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ZOOLOGICA
SCIENTIFIC CONTRIBUTIONS OF THE
NEW YORK ZOOLOGICAL SOCIETY
VOLUME 50 • 1965 • NUMBERS 1 TO 15
PUBLISHED BY THE SOCIETY
The ZOOLOGICAL PARK, New York
NEW YORK ZOOLOGICAL SOCIETY
GENERAL OFFICE PUBLICATION OFFICE
630 Fifth Avenue, New York, N.Y. 10020 The Zoological Park, Bronx, N.Y. 10460
OFFICERS
Fairfield Osborn
President
Laurance S. Rockefeller
Vice-President
John Elliott
Secretary
David Hunter McAlpin
Treasurer
SCIENTIFIC STAFF
William G. Conway
Paul Montreuil
John Tee- Van
Director, Zoological Park
Director, Aquarium
Christopher W. Coates
Director Emeritus, Aquarium
ZOOLOGICAL PARK
General Director Emeritus
Joseph A. Davis, Jr. . . . Curator, Mammals Herndon G. Dowling .... Curator, Reptiles
H. Bradford House . Assistant Curator, Mammals Victor H. Hutchison . . . Research Associate in
Grace Davall . . Assistant Curator, Mammals Herpetology
& Birds Allen Vinegar . . . Visiting Research Fellow,
Roland Lindemann . . Consultant in Mammal Herpetology
Management Charles P. Gandal Veterinarian
William G. Conway Curator, Birds Lee S. Crandall . . . General Curator Emeritus
Joseph Bell Assistant Curator, Birds & Zoological Park Consultant
AQUARIUM
Carleton Ray Curator Joseph R. Geraci Associate Curator
Louis Mowbray .... Research Associate in Field Biology
GENERAL
William Bridges .... Curator, Publications Dorothy Reville . . ,
John L. Miller . Associate Curator, Publications Sam Dunton . . . .
Henry M. Lester . . . Photographic Consultant
Jocelyn Crane
DEPARTMENT OF TROPICAL RESEARCH
Director Michael G. Emsley . . . .
Associates
Jane Van Z. Brower
Lincoln P. Brower
William G. Conway
Julie C. Emsley
William K. Gregory
Donald R. Griffin
David W. Snow
John Tee-Van
Editorial Assistant
. Photographer
Assistant Director
OSBORN LABORATORIES OF MARINE SCIENCES
Ross F. Nigrelli . . . Director and Pathologist
C. M. Breder, Jr Research Associate in
Ichthyology
Harry A. Charipper . . Research Associate in
Histology
Thomas Goreau .... Research Associate in
Marine Ecology
Martin F. Stempien, Jr.
Sophie Jakowska . . . Research Associate in
Experimental Biology
Klaus Kallman Geneticist
John J. A. McLaughlin . . Research Associate in
Planktonology
George D. Ruggieri, S.J. . Research Associate in
Experimental Morphogenesis
Research Associate in Bio-Organic Chemistry
EDITORIAL COMMITTEE
Fairfield Osborn
Chairman
William Bridges
Lee S. Crandall
Paul Montreuil
William G. Conway
Joseph A. Davis, Jr.
Herndon G. Dowling
Ross F. Nigrelli
Contents
Issue 1. May 28, 1965
PAGE
1. Courtship Behavior of the Queen Butterfly, Danaus gilippus berenice
(Cramer). By Lincoln Pierson Brower, Jane Van Zandt Brower &
Florence Pitkin Cranston. Plates I- VII; Text-figures 1-11 1
2. Observations on the Distribution and Ecology of Barker’s Anole, Anolis
barken Schmidt (Iguanidae). By J. P. Kennedy. Plate 1 41
3. Underwater Calls of Leptonychotes (Weddell Seal). By William E.
Schevill & William A. Watkins. Plate 1 45
4. Pulmonary and Cutaneous Gas Exchange in the Green Frog, Rana clami-
tans. By Allen Vinegar & Victor H. Hutchison. Text-figures 1-4. . . 47
5. Evoked Potentials in the Visual Pathway of Heliconius erato (Lepidoptera).
By S. L Swihart. Plates I-III; Text-figure 1 55
6. Neurosine, Its Identification with N-acetyl-L-histidine and Distribution in
Aquatic Vertebrates. By Morris H. Baslow 63
Issue 2. August 27, 1965
7. A New Trematode, Cathaemasia senegalensis, from the Saddle-bill Stork,
Ephippiorhynchus senegalensis (Shaw). By Horace W. Stunkard &
Charles P. Gandal. Text-figure 1 67
8. A Device for Sonic Tracking of Large Fishes. By George A. Bass &
Mark Rascovich. Plates I & II; Text-figures 1-5 75
9. Studies on Virus Diseases of Fishes. Spontaneous and Experimentally In-
duced Cellular Hypertrophy (Lymphocystis Disease) in Fishes of the New
York Aquarium, with a Report of New Cases and an Annotated Bibliog-
raphy (1874-1965). By Ross F. Nigrelli & George D. Ruggieri, S.J.
Plates I-X 83
10. Vortices and Fish Schools. By C. M. Breder, Jr. Plates I-IV; Text-figures
1-3 97
Issue 3. November 10, 1965
Page
1 1. Studies on Virus Diseases of Fishes. Epizootiology of Epithelial Tumors in
the Skin of Flatfishes of the Pacific Coast, with Special Reference to the
Sand Sole (Psettichthys melanosticus) from Northern Hecate Strait, British
Columbia, Canada. By Ross F. Nigrelli, K. S. Ketchen & G. D. Rug-
gieri, S. J. Plates I -XI; Text-figures 1&2 115
12. Waving pisplay and Sound Production in the Courtship Behavior of Uca
pugilator, with Comparisons to U. minax and U . pugnax. By Michael
Salmon. Plates I-V; Text-figures 1-7 123
13. Genetics and Geography of Sex Determination in the Poeciliid Fish, Xipho-
phorus maculatus. By Klaus D. Kallman. Text-figure 1 151
Issue 4. December 31, 1965
14. Speciation in Heliconius (Lep., Nymphalidae) : Morphology and Geo-
graphic Distribution. By Michael G. Emsley. Maps 1-30; Text-figures
1-173 191
15. A Technique for the Recording of Bioelectric Potentials from Free-flying
Insects (Lepidoptera: Heliconius erato) . By S. L Swihart & J. G. Baust.
Plates I & II 255
Index to Volume 50 259
ZOOLOGICA
SCIENTIFIC CONTRIBUTIONS OF THE
NEW YORK ZOOLOGICAL SOCIETY
VOLUME 50 • ISSUE 1 • SPRING, 1965
PUBLISHED BY THE SOCIETY
The ZOOLOGICAL PARK, New York
Contents
PAGE
1. Courtship Behavior of the Queen Butterfly, Danaus gitippus berenice
(Cramer). By Lincoln Pierson Brower, Jane Van Zandt Brower &
Florence Pitkin Cranston. Plates I-VII; Text-figures 1-11 1
2. Observations on the Distribution and Ecology of Barker’s Anole, Anolis
barken Schmidt (Iguanidae) . By J. P. Kennedy. Plate 1 41
3. Underwater Calls of Leptonychotes (Weddell Seal). By William E.
Schevill & William A. Watkins. Plate I. 45
4. Pulmonary and Cutaneous Gas Exchange in the Green Frog, Rana clami-
tans. By Allen Vinegar & Victor H. Hutchison, Text-figures 1-4. . . 47
5 . Evoked Potentials in the Visual Pathway of Heliconius erato (Lepidoptera) .
By S. L Swmart. Plates I-III; Text-figure 1 55
6. Neurosine, Its Identification with N-acetyl-L-histidine and Distribution in
Aquatic Vertebrates. By Morris H. Baslow. 63
Zoologica is published quarterly by the New York Zoological Society at the New York
Zoological Park, Bronx Park, Bronx, N. Y. 10460, and manuscripts, subscriptions, orders for back
issues and changes of address should be sent to that address. Subscription rates: $6.00 per year;
single numbers, $1.50, unless otherwise stated in the Society’s catalog of publications. Second-class
postage paid at Bronx, N. Y.
Published May 28,1965
1
Courtship Behavior of the Queen Butterfly,
Danaus gilippus berenice (Cramer) u 2
Lincoln Pierson Brower, Jane Van Zandt Brower
& Florence Pitkin Cranston* * 3
Biology Laboratory, Amherst College,
Amherst, Massachusetts
(Plates I -VII; Text-figures 1-11)
I.
II.
III.
IV.
V.
VI.
CONTENTS
Introduction
Acknowledgments
Page
... 1
... 2
Geographic Distribution and Taxonomy of
the Danainae 3
Scent Organs of the Danainae 3
A. Variation Within the Subfamily 3
B. Species Previously Studied 4
C. Structure and Histology of the
Abdominal Hairpencils 4
D. Structure and Histology of the Wing
Glands 6
E. Sexual Scents of Male Danainae 7
1. The Lycoreini 7
2. The Euploeini 7
3. The Danaini 8
F. Mechanical Interaction of the Hairpencils
and Wing Glands 8
Methods and Materials 9
A. Location and Ecology of the Study Area. 9
B. Rearing of the Females 10
C. Isolation and Aging of the Females ... .11
D. Presentation of the Females to the Wild
Males .12
E. Motion Picture Analysis 12
F. Tape Recording the Data 13
G. Numbers of Individuals Studied 13
Results 13
A. Description of the Courtship Behavior.. 14
1. Successful Courtship 14
2. Unsuccessful Courtship 16
3. Multiple First Aerial Component
Courtships 18
B. Quantitative Analysis of the Courtship
Behavior 19
1. Participation in the Seven Phases of
Courtship 20
2. Duration of the Courtship and Its
Phases 20
3. Sequence and Repetition of Phases in
the Courtship 28
4. Unsuccessful Courtships 28
iThis study is dedicated to the memory of Frank
Rinald.
Contribution No. 1,068, Department of Tropical Re-
search, New York Zoological Society.
3Present address : Dr. Florence Cranston Irvine, Strong
Memorial Hospital, Rochester, New York.
5. Lateral and Dorsal Copulation
Attempts 28
VII. Discussion 29
A. Courtship of the Queen Compared with
Other Danaines 29
B. Courtship of Euploeines and Lycoreines. . 30
C. Stimuli Involved in the Courtship 30
D. Function of the Hairpencilling 31
E. Functional Role of the Hairpencil-Wing
Gland Interaction 32
F. Speculation 33
VIII. Summary 33
IX. References 34
I. Introduction
THE study of sexual behavior of the Lep-
idoptera has contributed significantly to
the development of biology, particularly
in the fields of ethology (Baerends, 1959; Tin-
bergen, 1951), sexual selection (Richards, 1927;
Fisher & Ford, 1928; Brower, 1963), and chemi-
cal communication (Gotz, 1951; Karlson &
Butenandt, 1959; Wilson & Bossert, 1963).
Nevertheless, entire courtship patterns have been
described for only a few species, and our knowl-
edge of the roles that visual, tactile, chemical and
acoustic stimuli play is severely limited. This is
more true of the moths than the butterflies, but
even in the latter few adequate studies exist, and
it is with butterfly courtship that this paper will
be concerned. When one considers the diversity
in flight behavior, scent disseminating systems,
color, pattern, size and sound-producing organs
in these insects, the prospects for comparative
analyses are indeed fascinating.
There are three principal reasons why so few
comprehensive studies have been made: first,
entire courtships ending in copulation are rarely
seen in nature; second, when mating does take
place, the rapid series of complex events makes
recording extremely difficult; and third, there
1
2
Zoologica: New York Zoological Society
[50: 1
has been a remarkable lack of systematic experi-
mentation in the field, laboratory or insectary.
On the other hand, there are numerous fragmen-
tary references to pairs which have already
mated (Carpenter, 1935) and to incomplete
courtships, but in fact interpretations of the lat-
ter have often been incorrect, as Lederer ( 1960)
has pointed out.
Some of the best analyses of butterfly court-
ship have been done in the confinement of out-
door cages but the work of Crane & Fleming
(1953) and Crane (1955, 1957) has shown that
great care must be taken to be sure that the in-
sects have enough space, proper lighting, pro-
tection from wind and sufficient foliage to allow
their behavior to be normal. One example of
the possible pitfalls of this method was described
by Tinbergen, Meeuse, Boerema & Varosieau
(1942) in their experiments on the role of the
scent patches on the forewings of the male Gray-
ling butterfly ( Eumenis semele L.). An initial
finding that the removal of these had no effect
proved on closer study to be an artifact of crowd-
ing. Similarly, Stride (1958a) found that unre-
ceptive Hypolimnas misippus Linnaeus females
flew into the cage roof when pursued by their
males and were unable to exhibit their normal
evasive behavior. Moreover, in our work with
caged Queen butterflies, we found that the be-
havior of both sexes is incomplete and that the
males often trapped the females in corners where
copulation occurred.
Another valuable approach has been to pres-
ent males with dead butterflies, artificial dum-
mies or living butterflies that were restricted in
various ways. These methods have proved par-
ticularly useful in elucidating the stimuli in-
volved in the approach reaction of the male to
the female, and include attaching the dummies
and living or dead male or female butterflies to
wand-like rods (Tinbergen et al., 1942; Crane,
1955; Stride, 1956, 1957, 1958a, b), pinning
them to flowers (Magnus, 1950), tethering them
at the ena of threads (Tinbergen et al., 1942;
Brower, 1958) and tying them to leaves (Leder-
er, 1960).
This paper will present the results of another
method of investigating courtship in which lab-
oratory-reared female Queen butterflies, Danaus
gilippus berenice (Cramer), were released to wild
male Queens in their natural environment. It is
hoped that the new techniques developed for ob-
taining the data in a form that can be treated
statistically will prove a stimulus to further ex-
perimental research. The courtship behavior of
the Queen butterfly will also be compared as far
as is possible with that of other butterflies of the
subfamily Danainae as described in the literature.
No attempt will be made to compare the court-
ship of these butterflies with species of other
taxonomic divisions of the Rhopalocera since
this is to be the subject of a later publication.
Of particular interest is the major role that scent
appears to play in the courtship of the Danainae.
Consequently, the paper will summarize the lit-
erature on the morphology and histology of the
scent organs and will critically evaluate the in-
ferences as to their function that may be drawn
from their structure. As will be seen, the be-
havioral system in the Danainae that depends
upon scent stimuli opens a new area of investi-
gation in which it may be possible to reconstruct
the evolution of a chemical language that pre-
vents interspecific hybridization in nature.
II. Acknowledgments
Many people have provided assistance, en-
couragement and helpful criticism in the course
of this study. We are greatly indebted to Richard
Archbold, the late Frank Rinald and the staff of
the Archbold Biological Station in Florida where
the work was conducted during the summers of
1959-1961. In the summers of 1962-1964 the
research was continued at Simla, the New York
Zoological Society’s tropical research station in
Trinidad, West Indies, and we are particularly
grateful to Jocelyn Crane for her enthusiastic
support. The literature research and much of
the writing was done in Professor E. B. Ford’s
Laboratory of Ecological Genetics at Oxford
University, and the Hope Department of Ento-
mology library was used extensively with the
very able assistance of Mrs. Audrey Smith.
We wish to thank Professor E. B. Ford, F. R.
S., Dr. N. Tinbergen, Dr. Margaret Bastock
Manning and Miss Margaret Jones for reading
and criticizing the manuscript. We are also grate-
ful to Professor George Varley for making
Eltringham’s original histological material avail-
able to us, and to Lee Boltin for advice and help
with the photography.
Thanks are also extended to our Amherst
College and Mount Holyoke College under-
graduate assistants who accompanied us to
Florida or Trinidad, including P. W. Westcott,
C. T. Collins, T. Kohn, T. Pliske, J. Reiskind,
J. T. Hayes, F. G. Stiles, H. J. Croze and
Allison Hower.
This research would not have been possible
without financial support from the United States
National Science Foundation (Grants 8707,
20152 and 2291). Special National Institutes of
Health Fellowships ( 1-F3-GM20-178-01 and
1F3-GM-19-796-01) allowed the senior authors
a period of concentrated effort at Oxford for
writing and library research. To all we are most
grateful.
1965]
Brower, Brower & Cranston: Courtship Behavior of Queen Butterfly
3
III. Geographic Distribution and
Taxonomy of the Danainae
The Queen butterfly is a member of the family
Nymphalidae and belongs to the mainly tropical
subfamily Danainae. This subfamily is divided
into three tribes: the Lycoreini, whose members
occur only in the Neotropics and West Indies;
the Euploeini, whose members are limited al-
most exclusively to the Indo-Australian region;
and the Danaini, whose members are pantropical
with a few species extending into temperate
regions (Seitz, 1908; Fruhstorfer, 1910; Auri-
villius, 1911). In this paper the terms lycoreine,
euploeine and danaine will be used in specific
reference to these tribal divisions.
The taxonomic relationships of the Old and
New World danaines have never been satisfac-
torily worked out, although Forbes (1939) has
made the most significant contribution in this
respect. The reasons for this arise from nomen-
clatorial difficulties, the fact that taxonomists
have worked mainly with either New or Old
World material, and because the tribe is almost
certainly in a rapidly expanding phase of its
evolution.
It should be noted that the three best known
species of danaines which are often referred to
the genus Danaus are generically distinct. The
Monarch butterfly, familiarly known as “ Danaus
plexippus,” is in fact a member of a monotypic,
New World genus, and should be called Anosia
erippus (Cramer). It appears to occur as three
subspecies: Anosia erippus erippus (Cramer) in
southern South America; A. e. menippe
(Hiibner) in North America; and A. e. mega-
lippe (Hiibner) in the intervening areas. The
second species is “Danaus chrysippus” which has
been placed in another monotypic genus that
occurs widely in the Old World and is called
Limnas chrysippus (Linnaeus). Finally, the
Queen butterfly, Danaus gilippus Cramer, is a
New World member of the polytypic genus
Danaus which has a pantropical distribution.
The Old World Danaus, the New World Danaus,
and Limnas appear more closely related to each
other than any of them is to Anosia, the Mon-
arch.
According to Forbes, Danaus gilippus is one
of four New World Danaus species. Two of
these, D. gilippus and D. eresimus Cramer, are
widely distributed and occur as a number of
subspecies in the West Indies, Central and South
America and parts of southern North America.
The third, D. cleophile Godart, is limited to the
island of Hispaniola while the fourth, D. plex-
aure Godart, is found only in South America.
The subspecies studied in the present inves-
tigation was mainly Danaus gilippus berenice
(Cramer). This occurs throughout Florida, west
to Texas, and also in Cuba, but the latter popu-
lation may prove to be a distinct subspecies. It
has yet to be determined whether some of the
subspecies are in fact true species. For example,
D. g. berenice from Florida is very distinct in
color from the Trinidad D. g. xanthippus Felder,
and both differ in color and size from the Jamai-
can D. g. jamaicensis Bates. Some of the photo-
graphs are of the Trinidad subspecies, and refer-
erence will be made to this form on several
occasions.
IV. Scent Organs of the Danainae
The Danainae have attracted the attention of
numerous investigators ever since Fritz Muller
(1877b) speculated upon the functional rela-
tionship of two elaborate organs found in male
Danaus species. These are paired hairpencils
which the male can extrude from the end of his
abdomen, and pockets located on the upper sur-
face of the hindwings (Plate I). In discussing
the pockets, he said, “the position and shape of
these sexual cavities is such that the extremity
of the abdomen might easily be applied to them,
and as the hairs of the abdominal organs unite
in the form of a brush, it would not be impos-
sible, or even difficult, to introduce them into
the depths of the cavity.” (p. 619).
Thus began the biological mystery which en-
shrouds the physiological relationship of the
hairpencils and wing glands. To provide a basis
for solving this, the variation in occurrence,
position and structure of these two organs in
the systematic divisions of the subfamily Dan-
ainae will be reviewed. This will be followed
by a brief survey of the species so far studied,
and then by a detailed comparative examination
of the morphology and histology of both organs.
Following this there will be a discussion of the
sexual scents, and finally a summary of the
evidence that the males perform a solitary be-
havior in which they actually apply their hair-
pencils to their wing glands.
(A). Variation Within the Subfamily
As far as is known, the males throughout the
entire subfamily Danainae possess a pair of
abdominal hairpencils with the exception of the
species in the danaine genus Ideopsis which have
none, and those of the euploeine genus Hestia
which have four (Muller, 1877a; Seitz, 1908;
Haensch, 1909; Fruhstorfer, 1910; Forbes,
1939; Wheeler, 1946; Talbot, 1947). In con-
trast to the hairpencils, the glands on the wings
of the males are not found in all three tribes,
and there is considerable variation both in their
4
Zoologica: New York Zoological Society
[50: 1
form and position. Thus in the Lycoreini they
are altogether lacking. In the Euploeini they
occur on the hindwings of some species, the
forewings of others, and are absent from still
others. In the Danaini they are present on the
hindwings of all species and are usually con-
centrated in the form of a single patch (Amauris
and Parantica), a more complex pocket (Danaus
and Limnas ), or an even more complex pouch
(Tirumala). Sometimes, however, they occur dif-
fusely (Radena) or in the form of an undulating
band (Ideopsis). Because of these morphological
differences, wing gland will be used as a general
term, and wing patch, wing pocket and wing
pouch will be used as specific terms. As will be
seen, this terminology reflects their different
modes of origin in development from the pupal
to adult stage.
(B). Species Previously Studied
No histological investigations have yet been
made upon the lycoreines. Illig (1902) de-
scribed and figured the hairpencils of an un-
designated species of Euploea , Freiling (1909)
the hairpencils of Euploea asela Moore, and
Eltringham ( 1 9 1 5, 1935) the hairpencils of four
euploeines: Euploea core asela Moore, Trepsi-
chrois mulciber Hiibner, Tronga brookei Moore
and Hestia lynceus Drury. Eltringham also de-
scribed the patches on the forewing of the first
of these and on the hindwing of the second; the
other two lack areas of specialized scales on
their wings. For the danaines, Eltringham (1913,
1915) has investigated the wing glands and
hairpencils of eleven species: Amauris niavius
Linnaeus, A. psyttalea Plotz, A. egialea Cramer,
A. ochlea Boisd., A. hecate Butler, A. whytei
Butler; Tirumala petiverana Doubleday, T. lim-
niace Cramer; Parantica eryx Fab.; Limnas
chrysippus (Linnaeus), and Danaus lotis Cramer.
Muller’s (1877b) original paper gave a prelim-
inary histology of the wing pockets of the south-
ern South American Monarch butterfly. Those
of the North American Monarch have been
superficially investigated by Hausman (1951)
and Urquhart (1958, 1960). It is presumably
upon this subspecies that Illig (1902) carried
out his detailed study of both organs. Illig also
studied L. chrysippus, as did Eltringham ( 1915) .
Freiling (1909) described and figured the hair-
pencils of the African Danaus septentrionalis
Butler in great detail, but did not investigate
the wing pockets of this species. The only re-
maining danaine which has been studied is the
South American subspecies of the Queen butter-
fly ( D . gilippus gilippus Cramer). Muller
(1877b) compared the hairpencils and gross
histology of the wing pockets with those of the
South American Monarch.
(C). Structure and Histology of the Abdom-
inal Hairpencils
With the exceptions noted above, the hair-
pencils of the Danainae are paired organs lying
laterally inside the abdomen at the end of the
body and have arisen through invagination of
the intersegmental membrane between the 8th
and 9th sternites (Ehrlich, 1958). They have
been given a variety of names which allude to
their structure or function. “Hairpencil” refers
to the cylindrical bundle of individual hairs;
“abdominal” or “extrusible brush” to the fact
that when partially extruded it looks like a small
artist’s paint brush; “brush bag” to the structure
when normally retracted in the body, and “duft-
pinsel” because the brush is scented. They have
also been called “anal scent glands,” which is a
misleading term because they are neither con-
nected to nor derived from the digestive system.
The male butterfly extrudes both hairpencils
simultaneously by an increase in the pressure
of its abdominal body fluids. While various
muscles come into play to bring this about, as
far as is known there is no direct muscular con-
trol of the extrusion. On the other hand, there
is a large retractor muscle attached to the base
of each hairpencil which is mainly responsible
for retracting the organ (Plate VI, figure 1).
They can also be forced out by carefully squeez-
ing the posterior part of the male’s abdomen.
Plate I, figure 1, shows the abdomen of a male
Queen butterfly prior to being squeezed and
the hairpencils in their normal, completely with-
drawn position. Plate I, figures 2 and 4, show
them extruded to an extent of about 75%. Be-
cause the individual hairs are attached only at
their bases, the further out the pencil is forced,
the more it tends to splay. Plate I, figure 3, shows
the hairpencils completely everted. During
courtship, the Queen males sometimes extruded
them as far as this (Plate II, figure 1), but not
always (Plate II, figures 2-3). In Lycorea ceres
ceres (Cramer) which we have observed in
Trinidad, the hairs, unlike those of the Queen,
are extruded spontaneously when the living
males are handled (Plate V). This apparently
also occurs in the lycoreine genus I tuna (Muller,
1878) and in the euploeines (Fruhstorfer,
1910), which suggests that the hairpencils in
both these tribes play an additional role in pro-
tection, while in danaines they are used solely
in courtship.
The hairpencils of the Queen are about 4 mm.
long and .75 mm. in diameter (Plate I, figures
2 and 4). Those of the Monarch are much
smaller, while those of euploeines and lycoreines
are considerably larger, being up to 12 mm. in
length in one species of Lycorea (Illig, 1902) .
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Brower, Brower & Cranston: Courtship Behavior of Queen Butterfly
5
Except for the modifications discussed below,
each hairpencil consists of a bundle of hundreds
of scales which have become elongated as more
or less hollow hairs. Each of these hairs is con-
tinuous with one very large trichogen secretory
cell embedded in the basal tissue of the organ
(Plate VI, figure 1). Our own observations and
those of Illig, Freiling and Eltringham lead us
to accept the hypothesis that a secretion pro-
duced by these basal cells flows up their respec-
tive hairs and diffuses out or oozes through
small pores along their length. Presumably, the
minute globules between the hairs (Plate VI,
figures 1 and 2) represent this secretion. These
globules were observed by Illig in “Danaus
plexippus,” by Freiling in D. septentrionalis and
Euploea asela and by Eltringham in L. chrys-
ippus and D. lotis, although not in E. core asela.
This conflict with Freiling in regard to the latter
butterfly probably reflects a difference in their
histological techniques, but it could also be that
they were dealing with different species. Illig’s
findings that the globules are released at the
base of the hair where it enters the cell is almost
certainly an artifact of his preparation. Eltring-
ham (1915) provided evidence that the globules
in L. chrysippus are not chitinous since they
readily dissolve in eau-de-javelle.
Eltringham (1915, 1929) was unwilling to
accept the view that the hairpencils are secretory
organs in Limnas, Danaus, Amauris and Tiru-
mala, partly because he could find no glandular
cells in the hairpencils of Limnas and due to
his conviction that these organs become charged
with a secretion from the wing glands. How-
ever, we have found that the globules are present
between the hairs of sections of Queen hair-
pencils preserved prior to the time the male
emerged from its pupa. This new evidence, to-
gether with that of Brower & Jones (1965, see
section IV-E-3), proves that the hairpencils are
independent secretory organs in the Queen
butterfly, and it seems probable that they are in
all danaines.
We have also examined microscopically the
hairpencils of living Trinidad Queen males from
the time of hatching until several days old and
in all a black dust-like material was seen densely
packed between the hairs. Presumably these
particles are the analogs of the globules just
described. One wonders if they evaporate in situ
during the hairpencilling behavior or if they
shower forth as a rain of scented dust.
Brief mention will now be made of the hair-
pencils found in the remaining danaine genera
as described by Eltringham (1913, 1915). The
species of the genus Tirumala have only a single
type of hair, which is basically similar to those
in Limnas and Danaus. In Parantica as well,
only one kind of hair is found, but these exhibit
a further specialization in that distally they bear
small leaf-like structures which readily break
off to produce small particles. The function of
these is apparently similar to the particles pro-
duced in much larger amounts in Amauris. The
species of the latter genus are far more complex
than all the other danaines. For example, in
Amauris niavius there are three different kinds
of hairs: those arising from the base of the
gland, which are light in color and form one
tuft; those arising more distally on one side of
the gland, and forming an adjacent black tuft;
and those arising from the central part of the
organ. The central hairs are long, delicate,
threadlike structures segmented along their
length. These break up to produce numerous
minute particles which are found densely packed
between the other hairs and are presumably
wafted into the air when the hairpencils are
extruded. Eltringham thought that the hairs of
the black tuft are stiffer than those of the light-
colored ones and probably function to assist
in lifting the scales covering the wing patch,
thereby allowing the entire (?) brush to be
charged with secretion. In other species, the
stiff hairs are surrounded by the light ones and
form a central core. In Amauris egialea the
fragmenting hairs appear to be absent, but a
fourth quite different type is found arising from
the base of the organ and together they form
a cone protruding up into the center of the
light-colored hairs. These may not be hairs at
all, but rather scent-producing cells. However,
in Amauris ochlea a slightly different cone is
present and apparently does produce fragments,
and similar structures are present in other species
of Amauris.
Other variations on these basic themes are
seen in the hairpencils of the Euploeini, which,
however, do not produce the dust particles. The
genus Hestia is particularly remarkable in that
stiff hairs are apparently completely separated
from softer ones, with the result that the insect
has four hairpencils instead of two. It appears
from the observations of Illig (1902), Freiling
(1909) and Latter & Eltringham (1935) that
most of the euploeines possess two types of
hairs so arranged that the more distal ones splay
out at right angles to the proximal, inner ones,
giving an appearance similar to that of a daffodil
flower (see Freiling, Plate 16, figure 36).
Although Eltringham (1915, 1935, in Latter
& Eltringham) doubted that the hairpencils were
secretory organs in some danaine species, he
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held the opposite opinion for the euploeines.
In describing Tronga brookei, he said, “this
species has no brands or patches of scales on
the wing, and the brushes must therefore per-
form their scent-producing functions unaided”
(1915, p. 172). It is evident from this statement
that his reasoning was more strongly influenced
by gross morphology than glandular details.
This in turn undoubtedly resulted from the
limited amount of preserved material at his
disposal and it is a tribute to him that he was
able to produce as much information as he did.
In the lycoreines there are no wing glands
and since the hairpencils are odoriferous (sec-
tion IV-E) these organs must both produce
and disseminate the scent.
To summarize, the hairpencils seem definitely
to be secretory as well as scent-disseminating
organs in at least some species of all three tribes
of the subfamily. In the danaine genera Amauris
and Parantica, certain hairs are further special-
ized to produce fragments which mechanically
aid the scent-disseminating function of the hair-
pencil. As Eltringham emphasized 30 years ago,
there is still considerable uncertainty associated
with these organs, and it is clear that further
investigation of both their microstructure and
secretory activity is greatly needed. Besides the
specific variation, factors to be considered are
changes that occur in the development and
aging of individuals as well as observations of
the organs in living as opposed to preserved
material. Electron microscope examination of
the hairs and their gland cells along the lines
carried out by Barth (1960) on pierids would
also be of extreme interest in elucidating their
structure and function.
(D). Structure and Histology of the Wing
Glands
The following paragraph, taken nearly ver-
batim from Muller (1877b, pp. 616-617) gives
an excellent picture of the external morphology
of the wing pockets of the South American
Queen and Monarch butterflies (Danaus g.
gilippus and A. e. erippus): they are visible on
both sides of each hindwing as a small swelling
but are more prominent on the upper surface
(Plate I, figures 1 and 2). They are elliptical in
shape and lie closely parallel and posterior to
the second cubitus vein. In the Queen, each is
about 4 mm. long, by 1.5-2 mm. wide, while in
the Monarch they rarely exceed 2 mm. in
length by .6 mm. in width, even though the
Monarch is the larger of the two species. The
opening of the pocket is on the upper surface
of the wing. An area “denuded” of scales is
visible near the opening (Plate I, figure 2)
which Muller speculated resulted from abrasion
by the hairpencil as it was pushed into the
pocket.
The developmental origin of the wing pocket
sheds considerable light on its structure. Approx-
imately half of it arises through an evagination
of part of the upper wing membrane. When a
male has just emerged from its pupa, this evagi-
nated areas exists as a small flap-like projection
(Plate VII, figures 1 and 3), but as the wings
expand, this folds over the unevaginated portion
and forms the pocket (Plate VII, figures 2 and
4) ; to avoid confusion, it should be noted that
figure 1 is a section through a right wing pocket
and figure 2 a left wing pocket.
The inside of the pocket is lined with small
flat scales (Plate VII, figure 2). From our
studies of the Queen and those of previous
authors on other species, it is evident that these
scales arise from large cells which are arranged
in alternating rows with smaller cells, each of
which may (as in the Queen) or may not have
a very small filiform scale projecting from it.
The functional difference of these two cells and
their associated scales is not at all clear, but
it is certain that we are here dealing with an
active secretory organ. Evidence of this is seen
by comparing the section made through the
pocket 10 minutes after the male had hatched
(Plate VII, figure 1) with that of the 24-hour-
old male (Plate VII, figure 2). This shows that
the cells of the flat scales greatly enlarge during
the first day in the adult male’s life to fill nearly
the entire space between the upper and lower
membranes. Presumably secretion issues forth
from one or the other or both of the cell types
through the stalks of their respective scales and
accumulates so that it can interact with the
hairpencils when they are inserted. Note also
that the flat scales are arranged in such a way
that they will offer the least resistance to the
hairpencil during its insertion.
Certain of the conclusions that Urquhart has
made in his study of the Monarch butterfly are
incorrect. Without reference to Illig, Freiling
or Eltringham, he stated that a fluid, originating
in the wing vein adjacent to the pocket, flows
between the upper and lower wing membranes
and fills what he terms the “cavity” of the wing
pocket, “where it becomes transformed into a
white, spongy, wax-like substance” (1958, p.
10; 1960, pp. 53 and 151). By “cavity,”
Urquhart is referring to the collective glandular
tissue of the wing pocket, and not to its large,
obvious air space. He thus erroneously interprets
the gland cells as being an amorphous mass.
Moreover, it is highly doubtful that this vein
1965]
Brower, Brower & Cranston: Courtship Behavior of Queen Butterfly
7
supplies anything to the pocket that it does not
give to other non-specialized areas of the wing
(Illig, 1902). This seems verified for the Queen
butterfly by Plate VII, figure 2.
Although the wing glands of the danaine
genera Amauris and Parantica are less complex
patches, their histological structure is very sim-
ilar to the pockets of Danaus and Limnas.
This, however, is not the case with the danaine
genus Tirumala. In these butterflies, the wing
gland is a pouch which has arisen by invagina-
tion of the upper wing membrane and forms a
large space between the upper and lower wing
surfaces. During the development in the pupal
stage, it exists not as a pouch but as a flat area
on the upper wing membrane which produces
a copious amount of filamentous material. As
the butterfly hatches and invagination occurs,
this is incorporated within the pouch. According
to Eltringham (1915), the cells which elaborate
this material atrophy and are replaced by others
which greatly enlarge and produce an oily se-
cretion. This is discharged into the pouch and
is taken up by the filamentous material. Thus
in Tirumala, it appears that the wing glands
produce a form of dust which has to be trans-
ferred to the hairpencils, while in Amauris the
dust is produced in the hairpencil organ per se.
Nevertheless, the effect must be the same in these
two genera: the dispersal of scent around the
female is aided mechanically by its adherence to
the dust.
More evidence is needed for the wing glands
of the Euploeini, but as far as is known they do
not produce any kind of dust, although they
appear to be secretory (Eltringham, 1915, 1935;
Poulton, 1927).
(E). Sexual Scents of Male Danainae
It is of the utmost importance to emphasize,
as Fritz Muller (1877c, 1878) did nearly ninety
years ago, that the scents of butterflies can
arise from two different chemical systems: one
related to protection against predators, and the
other to sexual behavior. Characteristically, in
those species which are unpalatable to predators
(Brower & Brower, 1964) both sexes often have
a common repulsive scent, though in the female
it may be stronger. In contrast, the sexual scents
are usually limited to the males, and as Dixey
(1905, 1906a, b), Poulton (1906, 1907, 1927,
1929), Longstaff (1908), Eltringham (1925a),
Clark (1926, 1927), Pycraft (1939) and Ford
(1962) have pointed out for butterflies in gen-
eral, these are often agreeable to man. This is
a very important fact, but also is dangerously
tautological because there is no a priori reason
why chemical releasers of sexual behavior in
butterflies should smell pleasant to a member of
the Phylum Chordata.
Both repulsive and sexual scents may occur
in the same individual. Since the latter are often
produced in areas which are in some way shel-
tered from the air (Muller, 1877a, b, c, 1878;
Barth, 1959), they can easily be overlooked.
Unfortunately, many of the naturalists upon
whose observations the historical findings are
based did not consider these facts. Moreover, the
descriptions have had to be taken from indi-
vidual opinions which are qualitative and sub-
jective; for example, what appears pleasant to
one person may not appeal to another. The ad-
vent of gas chromatography has now provided
a means of quantitative comparison of even
minute amounts, but has not yet been used to
analyze butterfly scents, although it has for
moths (Rothschild, 1960). Hopefully, chrom-
atographic work in progress by L. Brower, T.
Eisner, J. Meinwald and T. Pliske will shed
much new light on this fascinating subject.
1. The Lycoreini
Muller (1878) described the hairpencils of
Lycorea sp. and Ituna ilione as smelling strong
and rather disagreeable. Longstaff ( 1914) stated
that the hairpencils of two “Lycorea atergatis”
individuals did not smell at all, and that those of
a third smelled slightly like a cockroach. He
indicated that his specimens came from either
Trinidad, W.I., or Venezuela, which suggests
that he was probably dealing with Lycorea ceres
ceres. This is the only lycoreine in Trinidad
(Kaye, 1921). Our research group has collected
hundreds of males of this species in Trinidad
and we are of the opinion that the scent of the
hairpencils is flowery, but at the same time
musky; curiously, men, more often than women,
consider it pleasant. Since these butterflies do
not possess the wing glands characteristic of the
other two tribes of the subfamily, there can be
little doubt that the hairpencils both secrete and
disseminate the scent.
2. The Euploeini
Longstaff (1905, 1908) stated that various
species of euploeines (and danaines) smelled
of acetylene, but did not definitely determine the
source of the smell. He later (in Lamborn,
Longstaff & Poulton, 1911), thought that neither
the hairpencils nor the wing glands produced it.
Dixey ( 1 906) , citing Wood-Mason, said that the
hairpencils of Euploea radamanthus Fab. are
finely vanilla-scented. Longstaff (1912) ex-
tended his review of euploeines and cited an
observation by Shelford that the hairpencils of
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Trepsichrois mulciber are sweetly scented, as
were those of Euploea montana Feld. Poulton,
Lever & Simmonds (1931) mentioned that the
hairpencils of Euploeas from Fiji smelled like
burnt gingerbread or caramelized toffee. As al-
ready mentioned, Eltringham’s (1915, 1935)
histological studies of Trepsichrois mulciber,
T ronga brookei, Hestia lynceus and Euploea
core asela led him to believe that the hairpencils
produce the scent in euploeines. There is thus no
evidence that the wing glands produce scents in
the euploeines, although in some species, as
noted above (section IV-D), they appear to be
actively secretory.
3. The D attain i
It is in this tribe that the greatest confusion
has resulted from failure to distinguish between
the protective and sexual scents. The major ex-
ception to this statement is the work of Muller.
In his classical papers he reasoned by analogy
with other butterflies that the wing pockets of
the South American Monarch and Queen pro-
duce the scent, which, however, he was unable
to detect on the wings of these butterflies. Muller
explained this apparent contradiction by saying
that the wing pocket was constructed to con-
serve the scent and would only give it up to the
hairpencils when they were inserted through the
narrow slit of the pocket. This appeared to him
a satisfactory explanation of the characteristic
scent of the hairpencils of these two species,
which he described as similar to but less intense
than the Lycorea hairpencils.
In our investigations of the Trinidad sub-
species of the Queen butterfly (Brower & Jones,
1965), we have smelled numerous wing pockets
of reared and wild males of a variety of ages and
in no instance were we able to detect a scent
arising from the intact wing pocket. On the other
hand, the hairpencils of reared males in which
the wing pockets had been sealed a few minutes
after emergence did develop a sweet scent, thus
proving that the hairpencils are independent se-
cretory organs.
We also disagree with Muller’s (1878) de-
scription of the scent as being unpleasant, but
agree that it is less intense’but broadly similar
to that of the lycoreines. Elusive differences de-
tectable to us exist in the Florida, Jamaican and
Trinidad subspecies. This is of great evolution-
ary interest and we hope to explore the problem
further.
Although Longstaff’s papers (1905, 1908)
mentioned that various danaines smell of cock-
roach, acetylene, muskrat, rabbit hutch, musty
dung, stale tobacco smoke, slightly pleasant,
sweet, etc., the results are inconclusive with re-
spect to which part of the butterfly they are ema-
nating from, as he himself later pointed out (in
Lamborn, Longstaff & Poulton, 1911).
Clark ( 1926, 1927) described the odor of the
female Monarch butterfly as rather strong and
disagreeable, resembling that of cockroaches or
carrots. The males have the same odor but in
them it is faint and overlaid with a very sweet
odor like that of milkweed or red clover flowers.
Apparently Clark thought that this was the sex-
ual scent which emanated from the wing pocket,
as he cited Scudder’s (1889) statement that the
scales of the pocket emit a slightly honeyed odor
distinct from the carroty smell which all the
scales possess. Hausman (1951) seems to have
accepted this uncritically and did not mention
the hairpencils at all. Urquhart stated that the
hairpencils of the Monarch smell like the flowers
of Spiraea. He also noticed a faint fragrant scent
on the wings of the male.
Finally, Lamborn (in Lamborn & Poulton,
1918) described the scent of the hairpencils of
A tnauris niavius dominie anus Trimen in the wild
as similar to aromatic snuff.
Considerable evidence points to the conclu-
sion that the hairpencils of the three tribes of
the Danainae produce a more or less fragrant
scent, and that the wing glands of the Euploeini
and Danaini either do not have any scent or, if
they do, it is indistinguishable to the human nose
from one of the component scents generally dis-
tributed over the wings or body of the butterfly.
(F). Mechanical Interaction of the Hairpen-
cils and Wing Glands
Although Muller (1877) originally argued that
the position of the wing glands is such that the
male could easily apply the hairpencils to them,
the actual behavior was hot recorded until 1911
when Lamborn (in Lamborn, Longstaff & Poul-
ton, 1911) observed it in Amauris niavius and
then again in Amauris egialea (in Lamborn,
Dixey & Poulton, 1912). Having noticed a male
settle on a leaf with its wings expanded, Lam-
born then saw the insect arch its abdomen dors-
ally. This resulted in bringing the posterior of
the abdomen to the level of the wing patches.
Following this, the male extruded the hairpencils
and by alternately flexing and straightening out
its abdomen, passed them back and forth over
the surfaces of the respective right and left wing
patches. In another instance (Lamborn, in Lam-
born & Poulton, 1913), the male A. egialea
snapped its wings together each time it com-
pleted a cycle of brushing the hairs across the
patches. Further details were observed in A.
niavius dominicanus (Lamborn, in Lamborn &
Poulton, 1918) : the stiff dark hairs were spread
1965]
Brower, Brower & Cranston: Courtship Behavior of Queen Butterfly
9
out fan-wise over the patch, while the light,
softer hairs were applied without fanning out. By
snapping the wings 10 to 12 times in 5 to 6 sec-
onds, the male was able to move the stiff hairs
over the patch while keeping the softer pencil
stationary. These observations confirmed Eltring-
ham’s (1913) suggestion that the stiff hairs prob-
ably function to lift up the covering scales of the
patch to facilitate secretion interchange with the
rest of the hairpencil. In one example, the dura-
tion of this behavior from the time the male first
extruded the hairpencils until it completely re-
tracted them was 1 minute and 40 seconds.
The only other danaine in which the mechani-
cal relationship has been observed is Pctrantica
agleoides Moore. Lamborn (1921) stated that a
male alighted on a plant, partially closed its hind-
wings, curved its abdomen dorsally and rubbed
the protruded but unexpanded hairpencils over
the patches at the rate of about 20 strokes per
minute. This behavior occurred for nearly five
minutes, after which he captured the insect. The
position of the wings of Parantica during this be-
havior is thus similar to that proposed by Muller
for Danaus. Urquhart ( 1958) was of the opinion
that the Monarch males juxtapose the two or-
gans, but gave no direct evidence other than that
he once observed a male sitting on a leaf with its
wings partially closed and the abdomen raised
and moving in a somewhat jerky way from side
to side. Stride (1958a) attempted to study the
interaction in L. chrysippus by putting a slow-
drying ink into the wing pocket, but was unsuc-
cessful.
In the present investigation of D. gilippus
Berenice, only two observations were made. One
male was seen sitting on herbage with its wings
closed dorsally. Owing to a small hole in the right
hindwing it was possible to see that it had bent
its abdomen dorsally and was attempting to push
the right pencil into the pocket. Instead it suc-
ceeded only in protruding it through the hole in
the wing. The other observation was made in-
advertently during the filming of an unsuccessful
attempt to copulate. The male paused and raised
its abdomen towards the right pocket. The hair-
pencil was not, however, extruded at this time.
It is probable that the males insert their hairpen-
cils into their wing pockets at frequent intervals
while they are not engaged in courtship.4 How-
ever, in our opinion, its occurrence during the
unsuccessful courtship was significant only as a
displacement activity. The fact that we observed
it during actual courtship only once in the entire
investigation strongly suggests that it is not a
4This has now been confirmed for the Trinidad sub-
species (Brower & Jones, 1965).
normal component of the interaction of the male
and female while they are together.
For the Euploeini, even less evidence is avail-
able. According to Latter & Eltringham (1935),
males of Euploea core asela have been seen ap-
plying the hairpencils to the scent area on the
forewing, but the details of the behavior are un-
known.
Thus the hairpencils seem to be the source of
the scent, but are applied by the males to the
wing glands. The possible functions of the be-
havioral interaction of these two glands will be
considered in the discussion after the use of the
hairpencils in the courtship has been described.
V. Methods and Materials
( A) . Location and Ecology of the Study Area
The experiments were conducted during the
summers of 1960 and 1961 in the vicinity of
the Archbold Biological Station in Highlands
County, south central Florida. During parts of
the Pleistocene Epoch when the sea level was
higher than at present, Florida was considerably
restricted in size, and the rolling sand-dune ridges
which now characterize the central highlands
were formed. (Deevey, 1949; Flint, 1957). Be-
cause of the topography and sandy soil, the area is
well drained and supports a specialized scrub flora
characterized by pines, palmetto palms and num-
erous species of bushy xerophytic trees (Davis.
1943). Among the herbs that grow within this
community are various species of Asclepias
(milkweeds) of the family Asclepiadaceae. These
serve as larval foodplants of the Queen butterfly
(Brower, 1961, 1962). The area has proved
commercially valuable for the growth of citrus
fruit and at the time of the study several new
orange groves were being developed. The har-
rowing operations employed in clearing the land
cut and spread the large tuberous roots of one of
the milkweed species, Asclepias tuberosa rolfsii
(Britton) Woodson. Consequently the plant was
temporarily abundant and supported a substan-
tial population of Queens.
The study area was specifically located at
Childs Station. Once inhabited, this now de-
serted railroad depot is an old field surrounded
by the new orange groves. Growing among the
grass and weeds were a few live oak trees,
Australian pines, and several overgrown, feral
cultivated shrubs including Mango and Hibiscus.
This presented an ideal situation for releasing
female Queens, because in the afternoon males
tended to fly in from the surrounding groves and
congregate in quantities sufficient for continuous
experimentation. Fortunately, their numbers
were low enough so that a courtship by one male
was not often interrupted by others.
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[50: 1
Preliminary work indicated that the courting
activity of this species is concentrated in the
afternoon so that it was decided to experiment
between 2 and 5 p.m. Eastern Standard Time.
The methods were worked out in June and July
of 1960, and the experiments were conducted
between July 22 and August 11 in 1960 and be-
tween July 2 and August 11 in 1961. Through-
out both summers laboratory-reared females
were presented to wild males in their natural en-
vironment according to the method described
below.
(B). Rearing of the Females
To obtain eggs for rearing quantities of but-
terflies, wild females were caught in the field and
temporarily stored in glassine envelopes (Ward’s
Natural Science Establishment, Inc.). When a
sufficient number had been captured, one to four
were released inside oviposition cages which had
been placed over blossoming young milkweed
plants (A . t. rolfsii). The cages were one-foot cubi-
cal structures consisting of a wooden frame with
plastic screening on the top and the three sides
and with plywood on the fourth to provide shade
during part of the day. During 1960 the females
were fed daily on a honey-water solution (ap-
proximately 1 part clover honey to 4 parts water)
to supplement the nectar, but in 1961 this was
not done because plants with sufficient flowers
were located and a maximum of two butterflies
was released in each cage. At intervals of 24
hours the eggs were collected with forceps by
plucking off the leaves and individual florets on
which they had been laid. These were put into
containers to prevent desiccation and taken back
to the laboratory where the larvae hatched and
were fed on A. t. rolfsii.
This foodplant was collected each day in the
orange groves or in recently cleared scrub areas
by breaking off the stems of young healthy plants
and accumulating them in plastic bags. It was
important to keep these bags shaded at all times
to prevent subsequent rapid deterioration of the
leaves. In the laboratory leaf-bearing stalks
were dipped in water to wash off the sand which
was splashed up on them by the heavy rainfall
that occurs in the region. After shaking off the
water, they were spread out on paper and al-
lowed to dry off, but not wilt. They were then
placed in an inch of water in quart plastic con-
tainers, covered with a plastic bag and stored in
a refrigerator until used later that day or early
the next. At the time of their use, they were
broken into short pieces still bearing their leaves,
and placed in the rearing containers. The leaves
on the basal part of the stalk deteriorated while
in the water and care was taken not to feed them
to the larvae.
During 1960, the rearing was done in the lab-
oratory, at first under variable conditions but
later in a controlled environment room which
proved highly advantageous. In this room eggs
were placed singly (by twos in 1961) in half-
pint containers with two or three fresh A . t. rolfsii
leaves. These containers are made of clear plas-
tic and are manufactured by the Wilpet Tool and
Manufacturing Company, Kearny, New Jersey
(Wilpak VSH No. 208). The internal measure-
ments are: height 4.7 cm., width at the top 8.9
cm. and width at the bottom approximately 7.5
cm. They have snap-on caps which have two
right angle air vents approximately 0.2 cm. wide
and .05 cm. deep. To help prevent desiccation
of the leaves and eggs in the container, two damp
cotton wads were added. These were about one-
half inch in diameter and had been immersed
in water and then squeezed out. All containers
were placed on a table approximately 36 inches
below a bank of G.E. 8-foot “slim-line” fluor-
escent lights, balanced with 18 artificial and 6
daylight tubes so as to simulate sunlight. The
surface area of the table corresponded to that
of the bank of lights and was approximately 96
by 48 inches. The lights were connected to a time
switch which turned them off at 8 p.m. and on at
8 a.m. in 1960, so that each day consisted of a
12-hour light and a 12-hour dark period. In
1961, they were set to come on an hour earlier
with a 13-hour light and 11-hour dark period.
In 1960, one large group of Queens was reared
at 25°C (77°F) and another at 30°C (86°F).
In 1961, all were reared at 28.3°C (83°F). Short
term fluctuations of temperature occurred to the
extent of ± 2°F and at rare intervals rose for
short periods (less than 1 hour) as much as 5°F
due to factors beyond our control. A fan circu-
lated air beneath the light bank during the
light period. At 25°C the mean development
time from oviposition to emergence of the adult
was 24.3 days, ranging from 22.8 to 26.9 days
± 3 hours. At 30°C corresponding rates were a
mean of 18.5 days, ranging from 16.8 to 19.9
days ± 2 hours (Brower, ms. in preparation). In
1961 the precise time of development was not
measured, but averaged slightly under three
weeks.
Between two and three days after oviposition
the eggs hatched. All containers were checked
once to twice daily, depending on the stage of
larval development. Towards the end of the
fourth instar, the larvae were isolated so as to
have one per container. The fifth instar larvae ate
voraciously and so required more frequent care
than the younger ones. Fresh milkweed leaves
were added daily, uneaten ones and fecal pellets
were cleaned out and moisture which had con-
densed on the inner sides of the containers was
1965]
Brower, Brower & Cranston: Courtship Behavior of Queen Butterfly
11
wiped out with a Kleenex tissue. The larvae were
not handled or removed from a leaf or stalk
since this causes high mortality. Instead, if they
were on a leaf, this was picked up, cut to mini-
mal size and replaced with the fresh food. The
larvae completed their development in about two
weeks and metamorphosed to chrysalids which
hatched approximately one week later. In 1960
the larvae formed their chrysalids on the tops
of the containers but this proved unsatisfactory
since the emerging butterflies became crippled
as they attempted to expand their wings within
the limited space. Therefore in 1961 larvae about
to pupate were transferred in the early afternoon
to a 2-foot cubical cage constructed of plywood
with a screen back and a hinged front screen
door. Their containers were opened and an ex-
cess of food was added. Within a few hours they
crawled to the top of the cage and began to spin
up as described in detail by Urquhart (1960) for
the Monarch butterfly.
During the course of rearing the animals in
the controlled environment room, it was found
that changes from instar to instar, from larvae
to pupae, and from pupae to adults assumed a
24-hour periodicity rhythm and preparation for
the changes always began late in the afternoon.
All adults hatched within one to two hours of
the artificial “dawn.” It thus appears that the
Queen butterfly has a circadian rhythm which
synchronizes development stages. Such “24-hour
clocks” are well known in other animals (Pitten-
drigh & Bruce, 1959; Beck, 1964).
The advantages of rearing under the con-
trolled conditions cannot be overemphasized.
Mortality due to disease, failure to develop prop-
erly or accidents in handling were less than 25%
from egg to adult. No epidemic diseases oc-
curred at all, whereas under variable room con-
ditions and less rigorous cleaning and feeding
schedules, mortality often was over 80%. The
synchrony in development obtained under the
controlled conditions is partly responsible for
this, since it enables one to avoid manipulation
at the critical time of change between successive
stages in development. In 1961, by setting up
approximately two dozen eggs at 24-hour inter-
vals, it was possible to produce a daily supply of
freshly emerging adults.
(C) . Isolation and Aging of the Females
Late in the morning after the butterflies had
hatched, the females were transferred from the
laboratory to outdoor cages (approximately 8
feet by 8 feet by 7 feet high) where they were
kept in isolation from males but not from each
other. During the summer of 1960, females
of ages varying from 1 day to 10 days post-
hatching were used. Their mating history prior
to a particular experimental courtship ranged
from virgin to four times previously mated,
though none was inseminated. The number of
times each underwent courtship varied from
once to 26 times over the ten-day span. In 1961
we extended the study to investigate the role
of visual selection by males when presented with
females of modified color pattern. Since we were
interested only in the effects of color, the pro-
cedure was standardized to eliminate the vari-
ables of age, number of times mated and num-
ber of times courted. All females were used only
on the afternoon of the second day after they
hatched and were released to males until mated
or until they had undergone a maximum of three
courtships without mating. In this way a female
which had been mated was not used again. Two-
day-old virgins were used for two reasons. First,
younger ones were apt to be insufficiently hard-
ened after emergence and therefore difficult to
handle without damage. Secondly, females older
than two days tended to fly out of the range of
easy recapture and often became lost after their
first release. In this paper, the 1961 findings are
limited to the experiments with females which
were not altered in color and served as normal
controls in the color modification experiments.
The results of the latter study have been sum-
marized elsewhere (Brower, 1963).
The butterflies were kept in the outdoor cages
and when they were to be used in the courtship
experiments were caught by hand and then put
into glassine envelopes and conveyed to the field
in a cylindrical 1.5 quart plastic container. In
1960 they were returned to the cages after their
use even if they had been mated, so that virgin
and non-virgin females were kept together. How-
ever, in 1 96 1 virgins were always kept separately.
During both summers the reared males were not
used except in some preliminary experiments
discussed below.
In 1960 the caged females were provided with
A . t. rolfsii flowers as a source of liquid food. The
stalks bearing the flowers were stripped of their
leaves and put into 8-ounce Coca-cola bottles
full of water which were wired at varying heights
from the ground to all sides of the cages. The
butterflies fed freely, but because the flowers
tended to senesce rapidly, it was necessary to
supplement them with honey solution. In 1961,
milkweed flowers were in short supply so the
butterflies were fed only the honey-water so-
lution.
At the time of release into the isolation cages,
each female was numbered with black “magic-
marker” (Cado Permanent marker, Esterbrook
Pen Co., Camden, New Jersey) so that it could
12
Zoologica: New York Zoological Society
[50: 1
be individually recorded throughout its use in
the experiments.
(D). Presentation of the Females to the Wild
Males
At the beginning of the study in 1960 several
different ways of presenting the females to the
males were attempted. They were first tied with
thread as described by Brower (1958) and the
thread attached to a stick as Tinbergen et al.
(1942) had done in studying the Grayling but-
terfly. In this way the female could fly at the
end of its tether and be presented to any passing
male. However, few sustained responses were ob-
tained, and the aerial component of the courtship
observed under natural conditions was not ade-
quately expressed.
In a second attempt we put several wild-
caught males into outdoor cages similar in con-
struction to those already described but consider-
ably larger. Females were then released by hand
to these males which did court and in some in-
stances succeed in copulating with them. How-
ever, the aerial component was again restricted
as the females flew towards the sides of the cage.
Moreover, because the males interfered with
each other, insurmountable problems of inter-
pretation resulted. An additional problem, simi-
lar to the one described by Stride (1958a) in
his cage studies of Limnas chrysippus, was that
the males, although they responded to the fe-
males initially, soon courted them with lowered
intensity and eventually ceased to exhibit sexual
behavior altogether.
We therefore returned to the field and tried
a new method of releasing females singly to the
wild males in their natural environment. Our
reason for not doing this before was based on
the knowledge common to all who have caught
butterflies: when released they almost invariably
fly off in a rapid escape flight. However, it was
discovered that the male could easily fly after,
overtake, court and often successfully mate with
her. This technique was therefore standardized
according to the following procedure: the fe-
male was removed from her storage envelope
and held gently at the junction of wings and
thorax between thumb and forefinger so that
her wings folded naturally over her dorsum. She
was then carried around in the courtship area in
this way until a male was found resting on or
flying over the herbage or feeding at flowers
(usually the composite, Bidens pilosa Linnaeus) .
Once located, the male became the “target” to
which the female would be thrown and it was
necessary to approach him carefully so as not
to stimulate his escape flight. If the male were
feeding or resting, we usually waited until he
flew up or was about to do so. The female was
then gently launched so that she would fly past
his anterior. This was successful in nearly all
instances. Occasionally, however, a female did
not fly when released but instead plummetted
to the ground. Such releases were disqualified,
as were those in which the male either did not
see the female or did not respond to her. When
the attempt failed for any of these reasons or
when the courtships terminated and the female
began to fly away, she was caught in a butterfly
net, brought back to the center of the area and
launched again. To make this procedure more
uniform, one of us served as launcher and the
other as netter.
Although wild males were present in the
courtship area at nearly all times, their numbers
were not sufficient either to allow the release
of each female to a different male, or to remove
males from the area after they had mated with
our females. However, we did mark the males
before we released them back into the natural
population. Consequently, it was always pos-
sible to tell whether a particular male which had
just mated with one of our females had mated
with others before, but we could not know
whether a courtship which failed to terminate
in mating involved one of these males or a new
one. Moreover, females were released to the
same male on several occasions, both on the
same and on different days. Thus all individual
courtships, although each is considered as a
single numerical unit, are not completely inde-
pendent in the statistical sense. However, this
lack of statistical independence is small both be-
cause few males mated with more than one ex-
perimental female and because the study in both
years was carried out over many days during
which there was a continual turnover of the
males. Moreover, we always captured the pairs
as soon as they had mated and gently separated
them. As a consequence, the males did not have
time to inseminate the females, which would
have lowered their sexual drive considerably
( Norris, 1 932) .
(E) . Motion Picture Analysis
It was not possible to take extensive motion
picture sequences for quantitative analysis be-
cause of the near impossibility of maneuvering
the camera close enough to the butterflies or
keeping it in focus during an entire courtship.
However, it was relatively easy to film individual
phases of their sexual behavior. To do this a
Bolex H-16 reflex camera (16 mm.) was used
primarily with the Kern Paillard 25 mm. Switar
lens, but also with the Som Berthiot Pan Cinor
25-100 mm. zoom lens, the K.P. 150 mm. Yvar
telephoto lens and the K.P. 10 mm. Switar wide
1965]
Brower, Brower & Cranston: Courtship Behavior of Queen Butterfly
13
angle lens. Ektachrome Commercial 7255 film
was used and most sequences were taken at 24
frames per second and a few in slow motion at
64 frames per second. The battery-operated Bo-
lex motor was used to film long scenes but it
does not operate at high enough speeds to take
slow motion scenes. A copy of the film made in
1960 was studied by single frame observation in
an editor and by projection. This was useful in
interpreting the behavior and suggested further
work, which was completed in the summer of
1961. In addition we also made an 18-minute
film which shows the courtship and the methods
used in studying it. (Brower & Cranston, 1962).
Copies of this may be rented or purchased from
the Psychological Cinema Register, Pennsyl-
vania State University, University Park, Penn-
sylvania, (P.C.R. film 2123K). Plate II, figures
3 and 4, were made from one behavioral se-
quence on the movie film. The individual color
positive frames were projected through an en-
larger onto a panchromatic black and white
negative film, and these were subsequently en-
larged to make black and white positive prints.
(Plate II, figures 1-2, were taken with a Hassel-
blad 500C camera with an 80 mm. Zeiss Planar
lens (Synchro Compur shutter) at 1/6000 of a
second (Ascor 323 electronic flash) on Kodak
Plus X Pan Professional black and white film.)
(F). Tape Recording the Data
Early in the summer of 1960 an attempt was
made to obtain quantitative results by having
one person observe and announce the events
while a second individual wrote them down.
However, the courtship takes place so rapidly
that this method proved inaccurate. Therefore
a small portable tape recorder5 was used to re-
cord verbally a precise description of each ex-
perimental courtship, thus permitting continuous
observation of the behavior as it occurred. In
the evening the recording was played back into
another tape recorder and a second tape was
made which served as a permanent record to be
analyzed later in detail. The original tape was
then erased and used for recording the next day’s
observations.
Because of the complexity of the courtship,
one of us announced the male’s behavior and
the other the female’s behavior. The fidelity of
the recorder was such that the two voices, even
if heard simultaneously, could easily be distin-
guished. Because of the small size of the recor-
der, it was possible to run after the courting but-
5“Midgetape Professional 500,” Mohawk Business
Corporation, Brooklyn, New York; battery operated, and
with transistors, this instrument is extremely durable,
weighs less than 5 pounds and measures only 9" X 4” X
terflies and keep close to them at all times, unless
they flew high into the air or into a tree, which
infrequently happened. Occasionally the pair
would fly through a bush and evade us. In such
instances, we would approach the bush from
opposite sides so as not to lose sight of them.
Even when this happened, the sensitivity of the
machine was still sufficient to record both voices.
Our voices did not appear to affect the butter-
flies during their sexual activities, although it
was necessary to be careful not to make quick
movements or to cast shadows on them.
Quantitative data were obtained by transcrib-
ing the verbal sequences to written ones and
then tabulating the frequency and duration of
each of the components in all courtships. Dura-
tion was determined with a stopwatch to the
nearest second. The methods of transcribing and
duration measurements are easily repeatable by
two people independently. The permanent tapes
were also used for rechecking the data and
proved exceedingly valuable for reference. For
example, in the course of the 1961 field work,
new hypotheses arose which were supported with
data by referring to the 1960 tapes.
( G ) . Numbers of Individuals Studied
In 1960, 187 courtships of 40 different fe-
males were recorded and analyzed. These fe-
males varied in age, mating history and the num-
ber of times courted, as described above. During
1961, 79 courtships of 41 two-day-old virgin
females were studied, making a total of 266
courtships of 81 females. As will be seen, even
though the 1960 females were heterogeneous
compared to those in 1961, the findings for the
two years, with minor exceptions to be discussed
below, are similar in nearly all respects. This is
most important because the hypotheses formu-
lated on the basis of the 1960 data were con-
firmed by the experiments in the second year.
The first section of the results will present the
descriptive aspects of the courtship, and the
quantitative comparisons will be considered in
the second part. The description was also partly
formulated from observations made during the
color-modification experiments in 1961, so that
a total of over 325 courtships of more than 125
females has been considered in arriving at the
conclusions presented in this paper.
VI. Results
The sexual behavior of the Queen butterfly is
a complex sequence of interactions of the male
and female. These occur in four main compo-
nents and consist of nine different phases (Table
1 ). This study will consider the first three com-
ponents of the courtship from the initial pursuit
14
Zoologica: New York Zoological Society
[50: 1
Table 1 . Components and Phases of Sexual
Behavior in the Queen Butterfly
I. First Aerial Component
Phase 1. Aerial pursuit
Phase 2. Aerial hairpencilling
II. First Ground Component
Phase 3. Ground hairpencilling
Phase 4. Hovering and striking
Phase 5. Copulation attempt
Phase 6. Copulation
III. Second Aerial Component
Phase 7. Post-nuptial flight
IV. Second Ground Component
Phase 8. Insemination
Phase 9. Termination of copulation
(phase 1) through copulation (phase 6) to the
beginning of the post-nuptial flight (phase 7).
The fourth component which includes two
phases, insemination and termination of copu-
lation, was not analyzed in detail. During court-
ship a male often repeated the various phases
leading to copulation and a considerable num-
ber of courtships consisted of two or more first
aerial components. These proved extremely im-
portant in elucidating the behavior and will be
called multiple first aerial component court-
ships.
(A). Description of the Courtship Behavior
1. Successful Courtship
When the female appeared in the visual field
of the male, he flew after her in an aerial pur-
suit (phase 1). She continued to fly and might
accelerate, but the male is capable of flying fas-
ter and rapidly overtook her in the air. As he
passed a few inches over her dorsum, his mode
of flight changed suddenly to a rapid bobbing,
and his extruded abdominal hairpencils were
rapidly swept up and down over her head and
antennae. During this aerial hairpencilling (phase
2, text-figure 1; Plate III, figure 1), the male
maintained his forward flight motion and though
he often buffeted the female, he always stayed
in front of her. The hairpencilling apparently
serves to disseminate the perfume over the fe-
male’s antennae as she flies through the air and
may also act as a tactile stimulus. She responded
to this activity by slowing her forward motion
and by descending towards the ground where she
alighted on available herbage.
As she landed, the courtship entered the first
phase of the ground component, known as
ground hairpencilling (phase 3, text-figure 2;
Plate II, figures 1-4). In this, the male continued
to hairpencil and buffet with the same bobbing
Text-fig. 1. Aerial hairpencilling, phase 2. The
male is above the female and his hairpencils are
shown partially splayed. Approximately .75 natural
size.
flight motion as before, except that he main-
tained a position close to her anterior without
moving forward. This phase was often particu-
larly intense as he rapidly danced in front of her.
A second directional component might be added
when he shifted from up and down to lateral
bobbing in which he swept his hairpencils back
and forth in front of her through a semicircular
arc up to about six inches in diameter.
The response of the female to the hairpen-
cilling male was either to fold her wings tightly
over her back or to flutter them while still hold-
ing on to the herbage. When the latter occurred.
Text-fig. 2. Ground hairpencilling, phase 3.
1965]
Brower, Brower & Cranston: Courtship Behavior of Queen Butterfly
15
Text-fig. 3. Hovering and striking, phase 4. The
male is shown at the moment of the downward beat
of his wings as he hovers above and in front of the
female.
the male usually retracted his hairpencils, hov-
ered a few inches above her, and intermittently
dropped momentarily onto her dorsum. This
phase of the courtship is called hovering and
striking (phase 4, text-figure 3; Plate III, figure
2), was extremely variable in duration, and was
short or even absent when the female was im-
mediately receptive; more will be said about it
below.
The folding of the wings by the female rep-
resents a positive reaction to the male’s hair-
Text-fig. 4. Lateral copulation attempt, phase 5.
The male is holding onto the undersurface of the
female’s left wings and is twisting his abdomen
towards hers.
pencilling and probably serves to stimulate his
next response which is to retract the hairpencils
and alight laterally to attempt copulation (phase
5, text-figure 4; Plate III, figure 3). He nearly
always alighted in the same direction that she
was facing by rapidly dropping from the hover-
ing position on to her right or left side. As he
alighted, he grasped the undersides of the fore-
and hindwings of the female with his meso-
and metathoracic legs in a position such that
the two butterflies formed an angle with their
parallel bodies at its base and their respective
appressed forewing tips at its apices. This angle
varied roughly from 45° to 90°. The male some-
times helped to balance himself by intermittently
fluttering or by holding on to the herbage in ad-
dition to the female’s wings. Shortly after
alighting on the female, the male twisted his
abdomen laterally and probed the lower area
of her hindwing in an attempt to make contact
with the tip of her abdomen. By this time he had
extruded his clasping organs and eventually
thrust his abdomen up between her hindwings,
located her genitalia and attached his claspers
thereto. He sometimes poked the undersides of
the female’s hindwing several times over most
of its area before he succeeded in contacting her
genitalia. It was not possible to observe the geni-
tal contact because the tips of their bodies were
hidden inside the female’s hindwings. (This dif-
ficulty could be overcome by cutting a small hole
in the wing of the female). The agility with
which the male maneuvered his abdomen is re-
markable and shows that it is a highly specialized
prehensile organ. Throughout the entire copula-
tion attempt, the female kept her wings folded
over her dorsum and appeared to remain pas-
sively quiescent. Both during and after the copu-
lation attempt, the male palpated the antennae
and dorsal head region of the female by alter-
nate movements of his right and left antenna
(text-figure 5).
Text-fig. 5. Antennal palpation by the male as the
female clings to herbage.
16
Zoologica: New York Zoological Society
[50: 1
Text-fig. 6. Post-nuptial flight, phase 7. The male
flies off carrying the quiescent female in copulo.
Shortly after copulation was achieved (phase
6), the male opened his wings slowly to an
angle of about 60° and then quickly closed them.
This wing-snapping might be repeated but usu-
ally occurred only once. It was invariably fol-
lowed by the post-nuptial flight (phase 7, text-
figure 6) which commenced as the male flew off
carrying the female suspended at the end of his
abdomen. As she was carried away upside down,
she neither struggled nor attempted to fly, but
kept her wings appressed and her legs folded
against her thorax. In no instance did the female
carry the male. The post-nuptial flight varied in
height and distance and was sometimes spec-
tacular. For example, when pursued by us, or
by a second Queen male, the male sometimes
carried the female as high as 80 feet and for a
distance of well over 1,000 feet. The flight ended
as he settled with her inconspicuously among
ground herbage or in a bush or tree (Plate IV).
If the pair was disturbed, the male reinitiated
this phase of their behavior. It seems most likely
that the function of the post-nuptial flight is to
carry the pair away from where they have been
so conspicuously active to a less obvious area
and thereby to reduce predation from vertebrate
enemies. Insemination (phase 8) occurs after
the pair has settled, and is followed by termina-
tion of copulation (phase 9) from about one to
several hours later. These two phases were not
analyzed in the present study.
2. Unsuccessful Courtship
The courtship can end during any of the first
five phases of the behavioral sequence, and ac-
tive termination by both sexes occurs (Table 2) .
A male would often pursue a female until he
caught up with her and then break away without
aerial hairpencilling. Other courtships progressed
into the aerial hairpencilling phase and then
ended as the male flew away. Since these court-
ships were unsuccessful because the male ac-
tively left the female during either phase 1 or
phase 2, they were termed aerial dismissal.
In other courtships the females gave definite
negative responses to the males in either of these
two phases. The first of these was aerial evasion
in which she kept flying and would not respond
to him by alighting. Her behavior included rapid
climbing and veering as well as hard downward
and straight line flight. Occasionally the pair
flew high into the air over distances comparable
to .the post-nuptial flight before the male would
finally leave her and fly toward the ground.
Table 2. Six Categories of Unsuccessful Courtship
Termination by the Male
Component of
Occurrence
1960
1961
Totals
A. Aerial dismissal
I
43
7
50 (27%)
B. Desertion*
II
38
7
45 (24%)
C. Homocourtship
II
13
3
16 (8%)
Subtotals
94
17
111 (59%)
Termination by the Female
D. Aerial evasion
I
9
2
11 (6%)
E. Rejection*
II
22
25
47 (25%)
F. Foliage evasion
I
11
8
19 (10%)
Subtotals
42
35
77 (41%)
Grand Totals
136
52
188
’"Arbitrarily determined as Desertion or Rejection if the ground component of the courtship lasted, respectively,
< 20 seconds, or > 20 seconds.
1965]
Brower, Brower & Cranston: Courtship Behavior of Queen Butterfly
17
A second way in which the female could avoid
the male was by foliage evasion. Sometimes she
would fly directly through a bush or tree and
the male would lose sight of her and search for
a few moments where she had entered. At other
times, she would fly into the foliage and im-
mediately alight, close her wings over her back,
and remain motionless. Again the male would
search but fail to find her. This behavior indi-
cates that the male is oriented primarily by sight
during the aerial pursuit phase of the courtship.
The female could also terminate the court-
ship after being induced to alight by not folding
her wings dorsally in response to the male’s hair-
pencilling. Rejection by the female was arbi-
trarily defined as an unsuccessful courtship
which lasted for more than 20 seconds in phases
3—5. It was in these courtships that phase 4,
the hovering and striking behavior of the male,
often became greatly prolonged. Instead of
folding her wings, the female would alternately
flutter and extend them laterally. The male
would hover above her while she was fluttering
and each time she stopped he would attempt to
alight dorsally on her outspread wings. If he suc-
ceeded, she would usually flutter again and drive
him off, but frequently he would attempt dorsal
copulation (text-figure 7). The female without
exception would prevent copulation from this
position by fluttering him off, by thrusting her
wings down in a single hard motion so that the
male would lose his balance, and/or by vigor-
ously twisting her abdomen away from the end
of his. Occasionally after a long period of this
activity, the male would succeed in alighting on
the female laterally, the position from which
copulation occurred. However, the female could
still resist his attempt by similar evasive move-
ments of her wings and abdomen (text-figure 8) .
These sustained periods of courtship often
came to an end as the male began to add a lateral
Text-fig. 7. Dorsal copulation attempt. The male
(his wings folded) is shown holding onto the out-
spread wings of the female as he unsuccessfully at-
tempts to mate with her.
Text-fig. 8. Evasive behavior of female during
a lateral copulation attempt. The male is shown
beneath the left wings of the female posturing
his abdomen towards hers. Simultaneously she
bends her body dorsally and thrusts her wings
ventrally, all the while clinging to the herbage.
component to his hovering flight, which gradu-
ally increased until he hovered more widely in
front of her and finally flew away. Her behavior
influenced his time of departure. If she closed
her wings as he hovered away and kept them
closed, he would leave her sooner than if she
fluttered them again as he hovered back towards
her. It has already been seen that the wing-fold-
ing is a positive stimulus to the male if he is close
to the female, but it also appeared to be a neutral
stimulus if he was far enough away: by closing
her wings she became inconspicuous so that he
could no longer see her.
Such long courtships frequently ended in
homocourtship. This occurred when another or
several other males were attracted by the visual
stimulus presented by the courting pair. The first
male would fly up towards the intruder which
in turn would respond to him instead of to the
female. The males would then often fly off to-
gether leaving the female behind. The proba-
bility of courtship ending in this way depended
both on its duration and on the numbers of
males in the area. Thus the longer the courtship
or the higher the population density, the greater
were the chances of its terminating by homo-
courtship. This activity was always of short dura-
tion and soon ceased as the males flew their
separate ways.
The male could also terminate the courtship
after he had induced the female to alight by
desertion, i.e. leaving the female after courting
her for ^ 20 seconds in phases 3—5 (Plate III,
figure 4). Sometimes he would hover in front of
her for only a short while and then fly away. At
18
Zoologica: New York Zoological Society
[50: 1
other times, he would attempt to copulate either
dorsally or laterally but without sustained vigor
and then leave her.
These findings clearly show that both sexes
have the power of rejection and can both termi-
nate the courtship during any part of the be-
havioral sequence prior to copulation. Moreover,
they show that the density of the local male
population is important in determining the out-
come of the courtship.
3. Multiple First Aerial Component Court-
ships
Many of the successful courtships did not fol-
COURTSHIP OF THE QUEEN BUTTERFLY
FEMALE BEHAVIOR MALE BEHAVIOR
appears
flies
alights on herbage
folds wings
acquiesces
post-nuptial
flight
pursues in air
overtakes and
hairpencils
hairpencils
while hovering
alights laterally
copulates
Text-fig. 9. Summary of the stimulus-response reaction chain in the courtship of the Queen butterfly.
The male behavior is shown on the right and the female behavior on the left.
1965]
Brower, Brower & Cranston: Courtship Behavior of Queen Butterfly
19
low the step-by-step sequence of phases described
above and summarized in Text-figure 9. Any of
the first five phases could be repeated several
times either alone or in various combinations
(Table 3). For example, a courtship might pro-
ceed to the attempt to copulate (phase 5) and
then revert to phase 4 as the male flew up from
the female and hovered in front of her. In other
courtships the hovering and striking (phase 4)
might be followed by ground hairpencilling
(phase 3) , or the male might revert directly from
attempting to copulate to ground hairpencilling
(phase 5 to phase 3). Often the male would alter-
nate between hovering and striking and attempt-
ing to copulate for long periods of time. Nearly
always when this happened, the male neither
hairpencilled again nor succeeded in mating un-
less the aerial pursuit flight was reinitiated. When
this occurred, the courtship was termed a multi-
ple first aerial component courtship and these
more often ended in copulation than did those
with a single aerial component (Table 4).
The greater chance of success in these multiple
courtships was not apparent until after the statis-
tical analysis of the 1960 data. This finding led
to the discovery of the functional significance of
the hovering and striking behavior of the male
(phase 4) which had been so noticeable in the
long courtships. In 1961, it became clear that
the female would often be induced to fly up again
by the hovering and striking of the male. As soon
as she flew up, the male would pursue her and the
courtship would start over again, often leading
through all the phases to copulation. Thus the
hovering and striking phase is of great import-
ance, since a female which is at first unreceptive
may eventually be mated if the male persists.
Moreover, it leads directly to the possibility of
sexual selection, because if two males have dif-
ferential stimulating powers, the more persistent
one will on the average be more successful in
mating.
(B). Quantitative Analysis of the Courtship
Behavior
The data tabulated from the tape records are
Table 3. Sequence and Repetition of the Phases in Successful Courtships in 1961
Courtship
No.
Phase sequence
Successful Courtships with Single First Aerial Component (N = 12)
24b
27a
185c
319a
1, 2, 4, 3, 5, 6, 7
43a\
59a )
65a /
67c (
1 42a 6
221a\
294a)
314a /
44b)
129a \
330a
198a
187a
191b
30a
120a
135a
114a
292a
297c
116a
143c
269a
1, 2, 3, 5, 6, 7
Successful Courtships with Multiple First Aerial Components
(N
=
15)
1,
2,
3,
2,
3,
5,
6,
7
1,
2,
4,
2,
3,
5,
6,
7
1,
2,
3,
5,
2,
4,
5,
6,
7
1,
2,
3,
4,
1,
2,
3,
5,
6,
7
1,
2,
4,
3,
4,
2,
3,
5,
6,
7
1,
2,
3,
2,
3,
5,
2,
3,
5,
6,
7
1,
2,
3,
4,
2,
3,
5,
3,
5,
6,
7
1,
2,
4,
3,
1,
2,
4,
3,
5,
6,
7
1,
2,
3,
4,
2,
3,
4,
2,
3,
4,
2,
3,
5,
6,
7
1,
2,
4,
3,
1,
2,
4,
5,
1,
2,
4,
3,
5,
6,
7
1,
2,
3,
5,
4,
2,
4,
5,
4,
5,
4,
2,
4,
5,
6,
7
1,
4,
1,
4,
1,
4,
1,
2,
3,
4,
2,
3,
4,
1,
2,
4,
2,
3,
4,
2,
3,
5,
6,
7
1,
2,
3,
4,
5,
4,
5,
4,
5,
4,
5,
4,
5,
4,
5,
4,
5,
4,
5,
4,
5,
4,
5,
4,
1,
2,
3,
5,
1,
3,
5,
6,
7
1,
2,
3,
4,
5,
4,
5,
4,
5,
4,
5,
4,
1,
2,
3,
4,
5,
4,
5,
4,
5,
4,
20
Zoologica: New York Zoological Society
[50: 1
Table 4. Relation of Single and Multiple First Aerial Component Courtships
to the Success of Courtship
Outcome of
Courtship
Category of Courtship
Totals
Single Aerial Component
Multiple Aerial Component
1960
1961
Total
1960
1961
Total
1960
1961
Total
Successful
30
12
42
21
15
36
51
27
78
Unsuccessful
119
36
155
17
16
33
136
52
188
Totals
149
48
197
38
31
69
187
79
266
% Successful
(20% )
(25% )
(21%)
(55%)
(48%)
(52% )
(27%)
(34%)
(29%)
Significance: by inspection there is no significant difference between the 1960 and 1961 data, which are therefore
lumped in a 2 x 2 contingency table. (Chi square = 23.6, d.f. = 1, P <; .001).
presented in full for 1961 (Table 5) to enable
verification of the analysis and to allow direct
comparison of future studies by variance analy-
sis. The various aspects of the data for both 1960
and 1961 as summarized in Tables 2, 4 and 6-9,
show that the findings for the two years are in
general very similar and justify the omission of
the detailed records for 1960 due to lack of
space. The analysis that follows will show (1)
the extent to which the butterflies participate in
the 7 phases of courtship, (2) the time spent in
each of the first 6 phases and in the whole court-
ship, (3) the sequence and repetition patterns
of the 7 phases, (4) the frequencies with which
courtship terminates prior to copulation due to
various causes and (5) the frequencies and signi-
ficance of dorsal and lateral copulation attempts.
1. Participation in the Seven Phases of Court-
ship
Table 6 and text-figures lOa-c summarize the
numbers and frequencies of participation in the
seven phases of courtship by successful, unsuc-
cessful and all courting pairs. The data are shown
separately as well as lumped for the two years.
The lumping is justified because inspection of
Table 6 indicates that the patterns for the two
years are similar. The lumped data will therefore
be considered first, and the minor differences be-
tween the iwo years will be discussed later.
Text-figure 10a demonstrates the regularity
with which successful courtships were based on
participation in all seven phases. Of the 78 in-
stances which led to copulation, 100% included
participation in phases 1, 5, 6 and 7, 95% in
phase 2, 87% in phase 3 and 82% in phase 4.
Moreover, as shown by Table 7, hairpencilling
occurred in either or both phases 2 and 3 in
100% of the courtships which were successful.
Thus copulation under natural conditions ap-
pears to be impossible in the complete absence
of hairpencilling. A comparison of text-figures
10a and b shows that several phases tend to be
omitted in unsuccessful courtships. Compared to
95% of the successful males which hairpencilled
in the air (phase 2) , only 48% of the unsuccess-
ful ones did. The difference is even greater in
ground hairpencilling (phase 3), being 87% and
29% respectively. Similar drops occurred in
phases 4 and 5. However, it is important to note
that the proportion of unsuccessful courtships
which entered the hovering and striking phase
(phase 4) was greater than the proportions en-
tering phases 2 and 3. In other words, sustained
courtships occur even though phases 2 and 3 are
omitted. Text-figure 10c shows the frequencies
in both successful and unsuccessful courtships;
this is the quantitative picture of the behavior of
a population with respect to participation in the
seven phases of courtship.
Several lines of evidence to be developed in
the course of this analysis all point towards the
conclusion that the 1961 females were both more
attractive and receptive than those in 1960. How-
ever, it is here difficult to separate cause and
effect. The females in some cases were more at-
tractive because they were more receptive, but
this was not always so. The differences in the
unsuccessful courtships for the two years are
suggestive in this respect. In 1961 a higher pro-
portion of courtships continued through phases
2-5, while in 1960 there was consistently less
participation in these phases. The only significant
difference between the two years in the successful
courtship category is in phase 4. This is almost
certainly to be explained by the greater female
receptivity and hence the by-passing of this phase
to a greater degree in 1961.
2. Duration of the Courtship and Its Phases
The duration of each phase in an individual
courtship was determined by taking the sum of
the times spent in its repetitions in that courtship,
and then tabulated as shown in Table 5. There
it can be seen that the individual courtships were
grouped into four categories: successful single
first aerial component courtships, successful mul-
tiple first aerial component courtships, unsuc-
1965]
Brower, Brower & Cranston: Courtship Behavior of Queen Butterfly
21
PARTICIPATION OF MALES IN SEVEN PHASES OF COURTSHIP (1960 + 61)
a) Successful males b) Unsuccessful males c) All males
(N =78)
(N = 188)
N = 266)
c: $
^ ^ -t:
£ <b
<3U Q g
S
< Of
!
Ci
c
■s
<5>
Xj X
5; v.
5 §
I ^
I <
<b <3f»
C: IS
§ 1 1
i|i
a Q,
,8“ fQ
<o <o
Text-fig. 10 a-c. Percentage of males participating in the seven phases of courtship, (a) 78 successful
courtships; (b) 188 unsuccessful courtships; (c) all 266 courtships representing the quantitative response
pattern of a large population. Data are in Table 6.
cessful single first aerial component courtships,
and unsuccessful multiple first aerial component
courtships. The individual values for each phase
within these categories were then added together
and their means calculated. These are summar-
ized for both years in Tables 8a-f. In addition to
showing the mean duration and range of each
phase of courtship, Tables 8a-f also show the
time spent in the particular phase as a percentage
of the total courtship time. These percentages
were used to construct figures lla-d, and the
total area under each of the curves represents
100% of the courtship time. The mean durations
of the entire courtship time within each of the
four categories were similarly calculated and are
shown in Table 8g.
Duration measurements for phases 1-4 were
easily made because each of these categories was
a discreet entity and did not overlap with any
other. This was also true for attempts to copulate
(phase 5) which were unsuccessful. However,
for those which were successful, it was necessary
to choose a criterion to indicate the end of the
attempt and the beginning of copulation. This
was the first wing-snap of the male, which in-
variably occurred in successful, but never in un-
successful, courtships. The experimental crite-
rion taken to set the limits of the duration of
copulation (phase 6) was the time between the
male’s first wing-snap until he flew off with the
female in the post-nuptial flight (phase 7). As
discussed above, this is not a measure of the total
duration of copulation, which in fact continues
throughout phase 8 (see Table 1). Nevertheless,
the fly-off marks the end of courtship per se and
is therefore biologically important. Moreover,
since the mated pairs were captured as soon as
they flew off, it was not possible to measure the
time span of the post-nuptial flight (phase 7).
The mean duration for all 266 courtships was
40.4 seconds and ranged from 1 second in a
courtship which consisted only of a short aerial
pursuit to 317 seconds in a long successful one
(Table 8g). (In another series of experiments
22
Zoologica: New York Zoological Society
[50: 1
Table 5. Duration and Number of Repetitions of Phases of 79 Successful and
Unsuccessful Courtships of 41 Females in 1961
All females 2-day-old virgins, experimentally courted < 3 times.
Letters a-c designate 1st to 3rd time courted.
Courtship
No.
2
No.
Cause of
Termination
(See Table 2)
1
Duration (Seconds) of Phase
2 3 4 5 6
Total
No. of Repetitions
of Phase
12 3 5
2
Successful Courtships with Single First Aerial Component (N =
24b 1 3 5 1 14 18 42
12)
1
1
1
1
3
27a
1
5
1
1
29
1
38
1
1
1
1
5
43a
7
3
2
0
8
9
29
1
1
1
1
11
59a
4
3
6
0
24
5
42
1
1
1
1
12
65a
3
1
6
0
9
3
22
1
1
1
1
15
67c
5
6
10
0
7
17
45
1
1
1
1
26
185c
1
1
1
1
11
1
16
1
1
1
1
52
142a
2
1
6
0
6
4
19
1
1
1
1
60
221a
1
3
2
0
7
2
15
1
1
1
1
68
294a
2
3
2
0
9
1
17
1
1
1
1
78
314a
3
2
3
0
15
0
23
1
1
1
1
79
319a
6
7
1
1
10
7
32
1
1
1
1
4
Successful Courtships with Multiple First Aerial Components (N :
30a 4 5 16 0 18 18 61
= 15)
1
3
3
2
7
44b
4
4
6
0
8
11
33
1
2
2
1
19
114a
3
8
31
65
25
3
135
1
4
4
1
20
116a
23
20
9
74
10
3
139
5
5
4
1
21
120a
2
7
10
1
33
29
82
1
2
3
2
22
129a
1
5
4
0
20
12
42
1
2
2
1
23
135a
3
7
2
2
5
0
19
2
2
2
1
27
187a
3
11
3
1
8
17
43
2
2
2
1
29
191b
2
3
13
2
21
7
48
1
2
2
1
38
269a
8
6
7
99
21
8
149
3
4
2
10
39
330a
2
4
3
1
5
2
17
1
2
1
1
55
143c
5
4
5
245
29
16
304
3
2
3
12
56
198a
2
19
1
1
10
1
34
1
2
1
2
67
292a
11
19
2
4
11
8
55
3
3
2
2
71
297c
1
11
9
15
29
9
74
1
3
1
4
6
Unsuccessful Courtships with Single First Aerial Component (N :
44a E 7 0 0 89 21 0 117
= 36)
1
0
0
21
8
51a
D
5
7
0
0
0
0
12
1
1
0
0
9
51b
D
8
45
0
0
0
0
53
1
1
0
0
13
67a
E
4
1
8
44
12
0
69
1
1
2
1
14
67b
F
2
22
0
6
0
0
30
1
1
0
0
16
113a
C
3
6
0
82
0
0
91
1
1
0
0
18
113c
E
3
0
0
102
0
0
105
1
0
0
0
24
185a
C
1
1
47
150
0
0
199
1
1
3
0
28
191a
E
3
1
77
181
0
0
262
1
1
3
0
30
245a
A
8
0
0
0
0
0
8
1
0
0
0
31
245b
E
2
0
26
32
0
0
60
1
0
1
0
34
248b
E
15
0
0
62
0
0
77
1
0
0
0
35
261a
E
1
1
3
90
3
0
98
1
1
1
2
37
261c
E
2
3
0
12
0
0
17
1
1
0
0
40
331a
E
1
0
0
21
0
0
22
1
0
0
0
41
331b
B
6
1
1
10
0
0
18
1
1
1
0
42
331c
A
6
0
0
0
0
0
6
1
0
0
0
43
19a
A
2
0
0
0
0
0
2
1
0
0
0
44
19b
F
6
16
0
12
0
0
34
1
1
0
0
47
20b
A
1
0
0
0
0
0
1
1
0
0
0
51
140c
E
1
2
4
17
1
0
25
1
1
1
1
53
143a
E
1
1
5
22
0
0
29
1
1
1
0
57
200a
A
1
0
0
0
0
0
1
1
0
0
0
continued
1965]
Brower, Brower & Cranston: Courtship Behavior of Queen Butterfly
23
Courtship 9
No. No.
Table 5, continued.
Cause of No. of Repetitions
Termination Duration (Seconds) of Phase of Phase
(See Table 2) 1 2 3 4 5 6 Total 12 3 5
Unsuccessful Courtships with Single First Aerial Component (N = 36), continued
58
200b
B
4
3
2
13
0
0
22
1
1
1
0
59
200c
E
3
9
0
21
0
0
33
1
1
0
0
61
224a
A
2
0
0
0
0
0
2
1
0
0
0
62
224b
B
3
0
0
3
0
0
6
1
0
0
0
63
224c
B
2
0
0
10
0
0
12
1
0
0
0
64
262a
B
3
0
0
2
0
0
5
1
0
0
0
66
262c
F
5
0
0
6
0
0
11
1
0
0
0
70
297b
F
2
3
2
10
0
0
17
1
1
1
0
73
302b
E
4
1
0
33
0
0
38
1
1
0
0
74
302c
E
1
5
4
40
11
0
61
1
1
1
1
75
307a
A
5
0
0
0
0
0
5
1
0
0
0
76
307b
E
1
0
43
99
61
0
204
1
0
2
10
77
307c E 1 0 0 71 15 0 87
Unsuccessful Courtships with Multiple First Aerial Components (N
1
= 16)
0
0
10
1
24a
F
9
29
29
9
103
0
179
4
9
7
4
10
51c
F
21
13
10
1
17
0
62
3
2
1
1
17
113b
E
1
3
21
180
1
0
206
1
2
2
1
25
185b
E
4
1
16
10
27
0
58
2
1
2
1
32
245c
E
4
0
16
34
0
0
54
2
0
1
0
33
248a
E
6
0
0
24
0
0
30
2
0
0
0
36
261b
E
6
4
20
187
22
0
239
4
4
3
15
45
19c
E
1
25
0
24
0
0
50
1
2
0
0
46
20a
E
5
14
37
86
0
0
142
1
6
6
0
48
20c
B
8
0
0
8
0
0
16
2
0
0
0
49
140a
B
4
9
16
83
0
0
112
4
6
5
0
50
140b
E
5
5
4
42
0
0
56
3
2
2
0
54
143b
C
1
2
5
70
0
0
78
1
2
1
0
65
262b
E
10
0
14
71
4
0
99
2
0
2
1
69
297a
F
7
19
2
1
0
0
29
2
1
2
0
72
302a
F
4
5
22
17
0
0
48
2
3
3
0
the longest of all courtships observed by us lasted
for 410 seconds, i.e., nearly 7 minutes!). A com-
parison of the means for successful courtships in
1960 and 1961 shows that both single and multi-
ple aerial component courtships lasted for com-
parable amounts of time in the two years. How-
ever, the unsuccessful ones were dissimilar in the
two years: in 1961 single and multiple aerial
Table 6. Participation of Males in Seven Phases of Courtship
Phase
Successful Males
Unsuccessful Males
All Males
1960
1961
Total
1960
1961
Total
1960
1961
Total
1
No.
51
27
78
136
52
188
187
79
266
Freq.
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
1.00
2
No.
47
27
74
60
30
90
107
57
164
Freq.
.92
1.00
.95
.44
.58
.48
.57
.72
.62
3
No.
41
27
68
30
25
55
71
52
123
Freq.
.80
1.00
.87
.22
.48
.29
.38
.66
.46
4
No.
48
16
64
75
43
118
123
59
182
Freq.
.94
.59
.82
.55
.83
.63
.66
.75
.68
5
No.
51
27
78
25
13
38
76
40
116
Freq.
1.00
1.00
1.00
.18
.25
.20
.41
.51
.44
6 & 7
No.
51
27
78
0
0
0
51
27
78
Freq.
1.00
1.00
1.00
.00
.00
.00
.27
.34
.29
Total
51
27
78
136
52
188
187
79
266
24
Zoologica: New York Zoological Society
[50: 1
Table 7. Relation of Hairpencilling to the Success of Courtship
Outcome of
Courtship
Courtship with:
Totals
Presence of
Hairpencilling
Absence of
Hairpencilling
1960
1961
Total
1960
1961
Total
1960
1961
Total
Successful
51
27
78
0
0
0
51
27
78
Unsuccessful
73
34
107
63
18
81
136
52
188
Totals
124
61
185
63
18
81
187
79
266
% Successful
41%
44%
42%
0%
0%
0%
27%
34%
29%
Significance: by inspection, there is no significant difference between the 1960 and 1961 data, which are therefore
lumped in a 2 X 2 contingency table. (Chi square = 48.5, d.f. — 1, P < .001).
component courtships both lasted for. a much
longer time than in 1960. This is another line of
evidence that the females in 1961 were more
attractive.
The average duration of all the successful
courtships was 55.2 seconds (Table 8g). The
shortest lasted for only 14 seconds, while the
longest carried on for 317 seconds. A vast dif-
ference exists in the duration of these, depending
on whether they are single or multiple aerial
component courtships, the latter lasting for an
average of 84.3 seconds, or nearly three times
as long as the single aerial ones (30.2 seconds).
Moreover, the range of single aerial courtships
is much less, being 14-69 seconds compared to
17-317 seconds. The time-frequency distribution
Table 8a. Duration of Aerial Pursuit (Phase 1)
Category of Courtship
% Duration
of
Total Courtship
Time in Seconds
Mean
Range
1960
1961
Total
1960
1961
Total
1960
1961
Total
Successful Courtships
Single Aerial
6.4
10.6
7.5
2.0
3.0
2.3
1-5
1-7
1-7
Multiple Aerial
7.7
6.0
7.0
6.6
4.9
5.9
2-49
1-23
1-49
Total Successful
7.3
7.0
7.2
3.9
4.1
4.0
1-49
1-23
1-49
Unsuccessful Courtships
Single Aerial
18.0
6.8
12.6
3.0
3.5
3.1
1-26
1-15
1-26
Multiple Aerial
7.1
6.6
6.8
4.7
6.0
5.4
2-8
1-21
1-21
Total Unsuccessful
14.0
6.7
10.3
3.2
4.3
3.5
1-26
1-21
1-26
Total Courtships
10.8
6.8
9.0
3.4
4.2
3.6
1-49
1-23
1-49
Table 8b. Duration of Aerial Hairpencilling (Phase 2)
Category of Courtship
% Duration
of
Total Courtship
Time in Seconds
Mean
Range
1960
1961
Total
1960
1961
Total
1960
1961
Total
Successful Courtships
Single Aerial
‘ 15.7
11.2
14.5
4.9
3.2
4.4
0-35
1-7
0-35
Multiple Aerial
18.8
10.8
15.6
16.1
8.9
13.1
0-167
3-20
0-167
Total Successful
17.8
10.9
15.2
9.5
6.3
8.4
0-167
1-20
0-167
Unsuccessful Courtships
Single Aerial
13.2
7.0
10.2
2.2
3.6
2.5
0-13
0-45
0-45
Multiple Aerial
9.5
8.8
9.1
6.4
8.1
7.2
0-32
0-29
0-32
Total Unsuccessful
11.9
7.8
9.8
2.7
4.9
3.4
0-32
0-45
0-45
Total Courtships
14.6
8.8
12.0
4.6
5.4
4.8
0-167
0-45
0-167
1965]
Brower, Brower & Cranston: Courtship Behavior of Queen Butterfly
25
Table 8c. Duration of Ground Hairpencilling (Phase 3)
Category of Courtship
% Duration
of
Total Courtship
Time in
Seconds
Mean
Range
1960
1961
Total
1960
1961
Total
1960
1961
Total
Successful Courtships
Single Aerial
5.5
13.2
7.6
1.7
3.8
2.3
0-13
1-10
0-13
Multiple Aerial
7.1
9.8
8.2
6.1
8.1
6.9
0-26
1-31
0-31
Total Successful
6.5
10.5
8.0
3.5
6.2
4.4
0-26
1-31
0-31
Unsuccessful Courtships
Single Aerial
5.5
12.1
8.7
0.9
6.2
2.1
0-16
0-77
0-7’’
Multiple Aerial
12.7
14.5
13.7
8.6
13.3
10.9
0-29
0-37
0-37
Total Unsuccessful
8.1
13.2
10.7
1.9
8.3
3.7
0-29
0-77
0-77
Total Courtships
7.4
12.3
9.6
2.3
7.6
3.9
0-29
0-77
0-77
Table 8d. Duration of Hovering and Striking (Phase 4)
% Duration
of
Time in
Seconds
Category of Courtship
Total Courtship
Mean
Range
1960
1961
Total
1960
1961
Total
1960
1961
Total
Successful Courtships
Single Aerial
Multiple Aerial
Total Successful
4.4
30.0
21.3
1.2
41.3
32.6
3.5
34.6
25.5
1.4
25.7
11.4
0.3
34.0
19.0
1.1
29.2
14.0
0-4
2-208
0-208
0-1
0-245
0-245
0-4
0-245
0-245
Unsuccessful Courtships
Single Aerial
Multiple Aerial
Total Unsuccessful
55.1
66.1
59.2
67.4
58.1
63.3
61.0
61.6
61.3
9.2
44.6
13.6
34.4
52.9
40.1
15.1
48.7
21.0
0-115
2-97
0-115
0-181
1-187
0-187
0-181
1-187
0-187
Total Courtships
41.5
53.4
46.9
13.0
32.9
18.9
0-208
0-245
0-245
Table 8e. Duration of Copulation Attempt (Phase 5)
% Duration
of
Time in Seconds
Category of Courtship
Total Courtship
Mean
Range
1960
1961
Total
1960
1961
Total
1960
1961
Total
Successful Courtships
Single Aerial
24.9
43.8
29.9
7.7
12.4
9.0
3-18
6-29
3-29
Multiple Aerial
22.3
20.5
21.6
19.1
16.9
18.2
3-155
5-33
3-155
Total Successful
23.2
25.5
24.1
12.4
14.9
13.3
3-155
5-33
3-155
Unsuccessful Courtships
Single Aerial
8.2
6.7
7.5
1.4
3.4
1.9
0-43
0-61
0-61
Multiple Aerial
4.6
11.9
8.7
3.1
10.9
6.9
0-25
0-103
0-103
Total Unsuccessful
6.9
9.0
8.0
1.6
5.7
2.7
0-43
0-103
0-103
Total Courtships
14.5
14.4
14.4
4.5
8.9
5.8
0-155
0-103
0-155
for successful single aerial component courtships
is nearly normal (i.e., Gaussian) whereas that for
successful multiple aerial ones is heavily skewed
to the right (Tables 5, 8g).
Moreover, this normal distribution is not char-
acteristic of single aerial courtships which are
unsuccessful. These, as well as the unsuccessful
multiple courtships, are skewed in a fashion simi-
26
Zoologica: New York Zoological Society
[50: 1
Table 8f. Duration of Copulation-Post-nuptial Flight (Phase 6)
Category of Courtship
% Duration
of
Total Courtship
Time in
Seconds
Mean
Range
1960
1961
Total
1960
1961
Total
1960
1961
Total
Successful Courtships
Single Aerial
43.2
20.0
37.0
13.4
5.7
11.2
1-31
0-18
0-31
Multiple Aerial
14.0
11.7
13.1
12.0
9.6
11.0
1-41
0-29
0-41
Total Successful
23.9
13.5
20.1
12.8
7.9
11.1
1-41
0-29
0-41
Unsuccessful Courtships
Single Aerial
0.0
0.0
0.0
0.0
0.0
0.0
0
0
0
Multiple Aerial
0.0
0.0
0.0
0.0
0.0
0.0
0
0
0
Total Unsuccessful
0.0
0.0
0.0
0.0
0.0
0.0
0
0
0
Total Courtships
11.1
4.4
8.1
3.5
2.7
3.3
1-41
0-29
0-41
Table 8g. Total Duration of Courtship (Phases 1-6)
Category of Courtship
Number of Males
Time in
Seconds
Mean
Range
1960
1961
Total
1960
1961
Total
1960
1961
Total
Successful Courtships
Single Aerial
30
12
42
31.0
28.3
30.2
14-69
15-45
14-69
Multiple Aerial
21
15
36
85.7
82.3
84.3
23-317
17-304
17-317
Total Successful
51
27
78
53.5
58.3
55.2
14-317
15-304
14-317
Unsuccessful Courtships
Single Aerial
119
36
155
16.7
51.1
24.7
1-125
1-262
1-262
Multiple Aerial
17
16
33
67.5
91.1
79.0
5-143
16-239
5-239
Total Unsuccessful
136
52
188
23.0
63.4
34.2
1-143
1-262
1-262
Total Courtships
187
79
266
31.4
61.7
40.4
1-317
1-304
1-317
lar to the successful multiple ones, the mean of
the single being 24.7 and ranging from 1-262
seconds, and the mean of the multiple being 79.0
and ranging from 5-239 seconds. There is, in
other words, a qualitative difference between
successful single aerial component courtships
and the rest; they tend very rapidly to proceed
to completion, whereas in the others the sequence
is broken, individual phases are repeated and a
disproportionate amount of time is spent in
phase 4.
Considering now the time spent in the individ-
ual phases of courtship, we see that phases 1
and 2 are roughly comparable for all four cate-
gories in 1960 and 1961 (Tables 8a and b). How-
ever, phases 3-5 (Tables 8c-e) are generally
longer in 1961 than in 1960, while the reverse
is true for phase 6 (Table 8f). Thus in 1961,
once a courtship began, more time tended to be
spent in ground hairpencilling, hovering and
striking, and attempting to copulate than in 1 960.
This again suggests that the 1961 females were
more attractive than those in 1960. Figures 11a-
d, based on Tables 8a-f, summarize the data for
the two years and illustrate that the first three
phases all take similar percentages of time ir-
respective of whether the courtships are success-
ful, unsuccessful, single, or multiple aerial com-
ponent; the range is also small, from 7.0 to
15.6% (2.1 to 13.1 seconds). However, the hov-
ering and striking (phase 4) is extremely vari-
able, from 3.5 to 61.6% (1.1 to 48.7 seconds),
and its analysis in relation to the four kinds of
courtship is of the utmost importance in illumi-
nating its functional significance. Text-figure 1 la
is a graph of the percentage of time spent in each
phase in all 266 courtships. This shows that as
a population the butterflies spend over three-fold
the amount of time in phase 4 than in any other
(46.9% in phase 4 compared to 14.4% in the
next largest, phase 5). Text-figure lib separates
the unsuccessful from the successful courtships
and shows that the unsuccessful males spend
more time (61.3%) hovering and striking. Nev-
1965]
Brower, Brower & Cranston: Courtship Behavior of Queen Butterfly
27
(a) (b)
(c) (d)
Text-fig. 11 a-d. Analysis of the average time spent in the first six phases of courtship. The duration of
each phase is expressed as a percentage of the total courtship time which equals the entire area beneath
each curve, (a) All courtships; (b) comparison of successful with unsuccessful courtships; (e) comparison
of multiple with single aerial component courtships which are unsuccessful; (d) comparison of multiple
with single aerial component courtships which are successful. See text for interpretation. Data are in
Tables 8a-8f.
ertheless, the successful ones do spend a sub- courtships into those with single or multiple aer-
stantial portion of time (25.5%) in this phase, ial components and shows that the percentage of
Text-figure 11c breaks down the unsuccessful time spent hovering and striking in both is vir-
28
Zoologica: New York Zoological Society
[50: 1
tually the same. However, this is not true of
successful courtships as shown in text-figure lid.
Hovering and striking is negligible in single aer-
ial component courtships (3.5% of the time)
whereas in multiple aerial component ones it oc-
cupies the major portion of the time (34.6%).
In fact, phase 4 in the successful single aerial
courtships consisted mainly of transitional hover-
ing lasting only one second and occurring be-
tween phases 2 and 3 or 5. Moreover, in these
instances the striking component was absent.
Since phase 4 is such a negligible feature in
these successful single aerial courtships which
are obviously the most efficient from the point
of view of time and energy expended, why then
is hovering and striking so prominent a feature
in all other courtships? The answer to this is
found partly in Table 4 which indicates that mul-
tiple aerial courtships are more often successful
than single aerial ones (P <.001 ). It was clear
in observing the behavior of the butterflies that
the hovering and striking occurred either when
the males omitted phases 2 and 3 or when the
females did not quickly fold their wings and be-
come receptive. Although at first unsuccessful,
the chances were high that mating could occur
if the male could sustain the courtship long
enough to reinduce the aerial component as in-
dicated by Table 4. In other words, hovering and
striking, as well as the dorsal attempts at copu-
lation, are functionally important because they
either directly stimulate the female to take flight
again, or they keep the male close enough to the
female so that when she does fly off he can re-
initiate the courtship.
The average proportion of time spent in at-
tempting to copulate (phase 5, Table 8e) in all
courtships is 14.4% (5.8 seconds), in successful
courtships 24.1% (13.3 seconds) and in unsuc-
cessful ones 8% (2.7 seconds). Little difference
exists between single and multiple aerial compo-
nent courtships within the successful and unsuc-
cessful categories. Finally, the time spent in cop-
ulation (phase 6, Table 8f) was 20.1% (11.1
seconds) for all successful males. It tended to
represent a much higher proportion of time of
the single aerial courtships (37%) than for the
multiple aerial ones (13.1%), but, as would be
expected, the actual time spent in this phase was
nearly equal for both (11.2 and 11.0 seconds,
respectively).
3. Sequence and Repetition of Phases in the
Courtship
In Table 3 the sequence and repetition pattern
for the phases of successful courtships in 1961
are summarized and it can be seen once again
that there is a qualitative difference between sin-
gle aerial and multiple aerial component court-
ships. Single aerial ones are highly regular and
with the exception of phase 4 (hovering and
striking), proceed in succession through the
seven phases. In 8 of the 12 courtships, phase 4
was omitted altogether and in the remaining
four it preceded phase 3; as noted above, in these
it consisted only of a period of approximately
one second during the transition from aerial to
ground hairpencilling as the female alighted.
Moreover, each phase occurred only once in all
of these courtships, and this was also true of all
but one of the 30 single aerial courtships in 1960,
in which the sequence was 1, 2, 4, 3, 4, 5, 6, 7.
In contrast, the multiple aerial component
courtships involved variable repetition of all the
phases, although even in these the normal se-
quence tends to be preserved. As seen in the
table, this is particularly true both near the be-
ginning and the end of the courtship. Further-
more, in the terminal portion, phase 4 is often
omitted as it is in successful single aerial court-
ships. The longest courtship in 1961 (no. 143c),
which lasted for 304 seconds, is illuminating in
this respect. This proceeded through the first 5
phases but then became very prolonged as the
male alternated between hovering and striking
the female and attempting to copulate with her.
Finally, after twice inducing her to fly off, the
courtship progressed rapidly through the normal
sequence to copulation.
It is thus evident that the sequence and repe-
tition of the phases leading to copulation is
highly stereotyped in the courtship of the Queen
butterfly, and it is clear that multiple aerial com-
ponent courtships are an elaboration of the basic
single aerial courtship in which phase 4 is par-
ticularly extended and repeated.
4. Unsuccessful Courtships
In Table 2 the data for unsuccessful courtships
in 1960 and 1961 are summarized, and it can be
seen that termination by the male or the female
occurred to about the same extent. Aerial dis-
missal by the male during phase 1 or 2 was re-
sponsible for ending 27% of the courtships. Of
nearly equal frequency were desertion by the
male and rejection by the female during the
ground component. Of somewhat less import-
ance, but nevertheless significant, was evasion by
the female either directly in the air or by flying
through foliage. These accounted for, respec-
tively, 6% and 10% of the unsuccessful court-
ships. Finally, homocourtship brought the se-
quence to an end in 8% of the cases.
5. Lateral and Dorsal Copulation Attempts
The only successful copulation attempts (phase
1965]
Brower, Brower & Cranston: Courtship Behavior of Queen Butterfly
29
5) are those that take place laterally (Table 9a) .
For both years, 250 attempts to copulate were
made of which 139 were lateral and 111 dorsal.
Fifty-six per cent of the lateral attempts were
successful, whereas none of the dorsal ones was.
The fact that the number of attempts from the
two positions did not depart significantly from
equality indicates the magnitude of importance
of the dorsal ones even though they never lead
to copulation per se. As already discussed, their
functional significance, together with hovering
and striking, is to reinduce the first aerial com-
ponent of the courtship and thereby greatly in-
crease the probability of achieving copulation.
Table 9b is an analysis of right and left lateral
copulation attempts and shows clearly that both
occur with a similar frequency and both are
about equally successful. There is thus no tend-
ency for asymmetry in mating position in the
Queen butterfly.
VII. Discussion
(A). Courtship of the Queen Compared with
Other Danaines
Observations of other danaine butterflies sug-
gest that their courtships are broadly similar to
that of the Queen, but sufficient data are not
available for quantitative comparisons. An in-
complete courtship of Limnas chrysippus was
noted by Marshall (1902) in which the male
was hovering above and intermittently dropping
dorsally onto a female as she clung to vegetation
and fluttered her wings. This appears compar-
able to phase 4 of the Queen and lasted for about
5 minutes before ending in homocourtship. What
appears similar to phase 3 was subsequently ob-
served by Carpenter (in Carpenter & Poulton,
1927). The male was seen hovering about four
inches above and in front of the female, rapidly
protruding and withdrawing its hairpencils. How-
Table 9. Relation of Male Position During Copulation Attempt
(Phase 5) to Success of Courtship
a. lateral vs. Dorsal Copulation Attempts
Position of Male with Respect to Female
Outcome of
Courtship
Lateral
Dorsal
Totals
1960
1961
Total
1960
1961
Total
1960
1961
Total
Successful
51
27
78
0
0
0
51
27
78
Unsuccessful
33
28
61
43
68
111
76
96
172
Totals
84
55
139
43
68
111
127
123
250
% Successful
61%
49%
56%
0%
0%
0%
40%
22%
31%
Significance: (1) by inspection there is no significant difference between the 1960 and 1961 data; in both years
copulation was achieved only from the lateral position (P < .001).
(2) in 1960, significantly more lateral than dorsal attempts to copulate were made (Chi square =
13.24, d.f. — 1, P < .001). In 1961, the apparent reversal of this tendency was not significant (x2 = 1.38; d.f. = 1;
.30 > P > .20). When the data for the two years are lumped, there is no significant difference in lateral and dorsal
attempts to copulate (^2 =r 3.14; d.f. = 1; .10 > P > .05).
b. Right vs. Left Lateral Copulation Attempts
Position of Male with Respect to Female
Outcome of
Courtship
Right Lateral
Left Lateral
Totals
1960
1961
Total
1960
1961
Total
1960
1961
Total
Successful
30
12
42
19
15
34
49
27
76
Unsuccessful
11
19
30
12
9
21
23
28
51
Totals
41
31
72
31
24
55
72*
55
127
% Successful
73%
39%
58%
61%
63%
62%
68%
49%
60%
♦Discrepancy from 84 in Table 9a due to omission in original tape records in 12 instances.
Significance: (1) the apparent greater success from the right in the 1960 data is not significant (Chi square =
1.16; d.f. = 1; .30 > P > .20). The apparent greater success from the left in the 1961 data is also not significant
(Chi square = 2.19; d.f. =c 1; .20 > P > .10). When the 1960 and 1961 data are lumped, there is no significant
difference (Chi square = .162; d.f. = 1; .70 > P > .50).
(2) Attempts to copulate from the left or right do not depart significantly from a .5 right: .5 left
expectation for both years (1960: Chi square = 1.38; d.f. = 1; .30 > P > .20; 1961: Chi square = .90; d.f. = 1*
.50 > P > .30).
30
Zoologica: New York Zoological Society
[50: 1
ever, the female was unreceptive and apparently
terminated the courtship by foliage evasion. An
experimental investigation on this species was
carried out by Stride (1958a). Having isolated
eight males in an insectary for six days, he then
released six females into the cage, and the males
immediately commenced courting them. Accord-
ing to Stride, the female normally flies in an
unhurried manner, but this is replaced in court-
ship by a rapid, rather jerky flight consisting of
a series of short dashes. This appears to be dif-
ferent from the Queen, but from then on their
courtship seems to be similar. “The male flew
above the female, and each time opportunity of-
fered he dipped down to strike the front part of
the female with his anal brushes. In a short time
the female settled on a leaf or the side of the cage
and the male settled beside her, facing the same
direction. Copulation was effected by a flexion
of the male abdomen in a forward direction. Any
further movement on the part of the paired but-
terflies was effected by the male . , (p. 229).
In the cage several males simultaneously hair-
pencilled a female but this group activity usually
ended in homocourtship.
Urquhart (1958, 1960) has described vari-
ous aspects of the courtship of the Monarch but-
terfly from which it may be inferred that the
aerial pursuit phase is similar to the Queen’s but
that the aerial hairpencilling phase is quite dif-
ferent. As the male pursues the female, she flies
from him in a spiral flight. He then overtakes
and apparently hairpencils her in small circles,
the pair thus rising in a vertical spiral. Neither
ground hairpencilling nor hovering and striking
was noted. However, it may be that what Urqu-
hart described as a walking phase is comparable
to the hovering and striking phase of the Queen
since both occur when the females are unrecep-
tive in the ground component. In this the male
Monarch struts in front of the female and opens
and closes his wings while she remains stationary
with her wings folded dorsally or only slightly
opened. Simultaneously, she was often seen ex-
tending her proboscis as if to feed, which Urqu-
hart speculates is in response to a flowerlike scent
emanating from the male’s wing pockets. We
did not observe this in the Queen. Copulation
followed lateral attempts as in the Queen. Three
aspects of elusive behavior by the female also
appeared similar to the Queen: aerial evasion
during the pursuit, wing thrusting and dorsal
twisting of the abdomen during the copulation
attempt.
Two incomplete courtships in Amauris psyt-
talea Plotz were noted by Carpenter (in Carpen-
ter & Poulton, 1914, 1929) in Africa. A male
was seen (1914) pursuing a female which settled
with her wings open on a dead flower stalk. The
male then hovered about four inches over her
head, rising and falling a little, but on the whole
at about the same level. During this his abdomen
hung down and at intervals of a few seconds he
rapidly extruded and withdrew the hairpencils.
The courtship went on for about a minute before
the female flew away, pursued by the male. Dur-
ing the hairpencilling the female sat quietly ex-
cept for an occasional slight movement of her
wings, which she apparently kept open the whole
time. Presumably, the very sudden protrusion of
the hairpencils and equally rapid withdrawal
causes the dust produced in enormous quantities
by this species to sprinkle forth over the anterior
of the female. The later observation (1929) was
less complete than this and the only difference
was that the female was pursued by several
males prior to her settling. Apparently the only
other recorded courtship of danaines is that of
Tirumala limnace, observed by Punnet (in Poul-
ton & Punnet, 1927) and again it is an incom-
plete observation of a pair in the ground compo-
nent in which the female seemed to be unrecep-
tive. The use of the hairpencils was not noted.
( B ) . Courtship of Euploeines and Lycoreines
Our knowledge of euploeine courtship is even
more limited, only Euploea core asela having
been observed. According to Latter & Eltringham
(1935), the female flies to the male and the pair
then fly about each other through the air, settle
on herbage and mate. Sevastopulo (in Sevas-
topulo & Carpenter, 1944) noted a male hover-
ing about two feet above a female which was
sitting on a leaf with her wings closed. During
this, the male protruded and withdrew its hair-
pencils, and every few seconds flew lower and
buffeted the female. This continued until the
female flew away closely followed by the male.
Thus there is evidence that the Euploeini differ
from the Danaini in that the female is attracted
to the male; more will be said about this below
(section D). Otherwise, the fragmentary obser-
vations suggest that the behavior of these two
tribes is similar.
Observations of lycoreine courtship are com-
pletely lacking.
(C) . Stimuli Involved in the Courtship
In the absence of experimental studies in
which artificial dummies or machines (Magnus,
1958) are employed, it is not possible to be cer-
tain what stimuli are acting, and at what time
they are effective. However, it seems valuable
in the light of what is known about other butter-
flies, to attempt a logical analysis of what stimuli
are involved in the courtship of the Queen.
1965]
Brower, Brower & Cranston: Courtship Behavior of Queen Butterfly
31
Let us begin by examining the role of the
visual stimuli. It seems reasonably certain that
the Queen male is initially attracted to the female
by seeing her in flight or while she is fluttering
at rest on herbage. Urquhart has noted that
Monarch males pursue numerous species of
butterflies in the wild, provided they are large
enough, and Magnus (1963) has argued force-
fully for a relatively unspecific but definitely
visual initial stimulus for butterflies in general.
During the course of our observations, we re-
leased a few females of Limenitis archippus
floridensis (Strecker) to Queen males and found
that they pursued these and even hairpencilled
one in the air. This species is a member of a
different subfamily, the Nymphalinae, and al-
though very similar to the Queen in appearance
(it is in fact a mimic of the Queen), it must
offer numerous other general and specific stim-
uli. The importance of size, pattern, type of
movement and color remain to be determined
by experiments along the lines of those carried
out by Tinbergen et al. (1942), Magnus (1950,
1958), Petersen, Tornblom & Bodin (1952),
Petersen & Tenow ( 1954) , Crane ( 1955, 1957) ,
Stride (1956, 1958a & b), Lederer (1960) and
Ford (1962). However, slight changes in color-
pattern seem unimportant. A series of experi-
ments was conducted in which females were
painted either to eliminate the white spotting
on the forewings or to increase its area on the
forewings. Courtship ended in copulation as
often with these color-pattern modifications as
with the painted controls (Brower, 1963).
The role visual stimuli play in the later stages
of courtship is unknown, but they are probably
involved whenever the male has to pursue the
female through the air for more than a few
inches. The fact that a female could easily evade
the male at a short distance by flying through
herbage supports this, as does his response to
a female during his wide hovering and her in-
termittent fluttering in prolonged unsuccessful
courtships. Moreover, termination by homo-
courtship suggests a conflict of objects offering
similar visual stimuli. The female Queen also
apparently responds visually to the male during
the first aerial component of the courtship. Our
interpretation is that her first reaction to the
pursuing male is to avoid the visual stimulus
he presents by initiating a generalized escape
flight which as described above is usually vig-
orous and sustained. The very great modification
of her behavior once she is overtaken and hair-
pencilled by the male in the air supports this
and appears to represent a change from visual
to chemical or chemo-tactic stimuli. The fact
that no courtships were successful unless hair-
pencilling occurred, in addition to the fact that
these organs are scented, argues strongly in favor
of the idea that scent is the dominant stimulus to
the female at this time. A bioassay technique
must be developed to verify this because the pos-
sibility that the hairpencilling is exclusively a
mechanical stimulus has not yet been disproved.
Whether the Queen female seeks out males
by looking for them as other species do (Lederer,
1960) is unknown, as is the question of whether
the male’s specific color-pattern is of importance
to her in the early or later stages of the court-
ship. There are cogent reasons for thinking that
the male’s color-pattern is of great importance
in some butterflies (Brower, 1963).
It is difficult to ascertain what stimuli the male
is responding to during the hairpencilling phase
of the courtship, but it seems more likely that
he is visually or tactilely and not chemically
oriented to the female. Our observation of a
male hairpencilling a Limenitis female in the
air suggests this, as does Stride’s (1958a) ob-
servation of a male L. chrysippus hairpencilling
a dead Hypolimnas misippus Linnaeus female
(Nymphalinae) which he held in his hand. The
vigorous movements of the male in orienting to
copulate with the female almost certainly stim-
ulate both partners tactilely. The fact that the
male’s tarsi usually cling to the undersides of
the female’s wings at this stage could offer addi-
tional tactile stimulation and at the same time
convey chemo-tactic information to the male.
The palpation of the female’s antennae and head
by the male’s antennae could similarly convey
chemotactic information, or it could be simply
mechanical stimulation (see Magnus, 1950). The
antennae of the two sexes might also be sensing
volatile substances emanating from each other.
The possible role of auditory stimuli arising
from the buffeting contact of the two butterflies
during the aerial and ground hairpencilling
should also be investigated, as sound apparently
does play a part in the courtship of some species
(Muller' 1878).
(D). Function of the Hairpencilling
If the interpretation presented in the last sec-
tion proves to be correct, then the hairpencil
perfume of the Queen male is to be regarded as
a pheromone which acts as a chemical arrestant
of the female’s escape flight from the pursuing
male. This follows the useful terminology set
forth by Dethier, Browne & Smith (1960). As
such, the perfume would be a proximity stimulus
and would serve not only to arrest the female’s
flight, but also to inhibit her from flying away
from the male once she had been induced to
alight.
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Zoologica: New York Zoological Society
[50: 1
In the Euploeini, the function of the hairpen-
cils may include an aspect which is completely
different from the danaines. Several observa-
tions have been made, mostly on Euploea core,
in which males have been seen patrolling certain
areas with their hairpencils fully extended in the
complete absence of females (de Niceville, 1872,
in Clark, 1926; Champion & Poulton, 1930;
Fyson & Poulton, 1930; Sevastopulo & Carpen-
ter, 1944). Latter & Eltringham (1935) have
provided evidence that this behavior attracts fe-
males from a distance. Courtship then proceeds
in the normal danaine manner. More work is
needed to verify that the hairpencils are attrac-
tive and if so that they act chemically and not
visually, since these organs in the euploeines
are extremely conspicuous when extended. If
visual attraction is not involved, then the ques-
tion arises, are the males producing a single
scent which is both an attractant at a distance
and an arrestant when applied in the normal
hairpencilling, or are two chemicals produced,
perhaps one by the hairpencils and one by the
wing glands?
( E) . Functional Role of the Hairpencil—Wing
Gland Interaction
The physiological role that the interaction be-
tween these two organs may serve involves sev-
eral possibilities, some of which can be elimi-
nated, at least in the Queen butterfly.
It is unreasonable to accept the original hypo-
thesis put forward by Muller (1877b) which so
greatly influenced the thinking of all subsequent
investigators. That is to say, it is very doubtful
( 1 ) that the wing glands per se produce the odor-
iferous substance and that the hairpencils per se
distribute it, both because the hairpencils are
complex secretory organs and as shown else-
where (Brower & Jones, 1965) produce scent
even when the wing pockets are sealed from
birth.
Let us therefore consider the reverse hypo-
thesis, namely (2) that the hairpencils per se
secrete the scent and the wing glands per se dis-
seminate it. This seems ruled out by the fact that
the hairpencilling behavior is a prerequisite to
successful courtship and by the form of the hair-
pencils when they are splayed, which on theo-
retical grounds alone makes them highly efficient
distributive structures.
A third possibility, originally put forward by
Eltringham ( 1935) is (3) that although only the
hairpencils smell noticeably to human beings,
both they and the wing glands produce sub-
stances which play completely independent and
non-interacting roles in stimulating the female.
This seems unlikely in view of the male’s behav-
ior in which he juxtaposes the two glands. Fur-
thermore, in the Queen butterfly, new evidence
suggests that the secretions of the two glands do
interact (see hypothesis 6 below).
This leads to Urquhart’s (1958, 1960) sug-
gestion (4) that only the hairpencils produce the
scent, but that both glands disseminate it. This
author reasoned that the perfume must be pres-
ent throughout the courtship. Since the hairpen-
cils are withdrawn during the attempt to copu-
late, they could not directly stimulate the female
at this time. But, if the juxtaposition of the two
glands prior to courtship transfers some of the
hairpencil perfume to the wing glands, then the
scent would be continuously present and copu-
lation could ensue. However, this storage hypo-
thesis seems doubtful, first of all because the
scent is undetectable or extremely faint in the
wing glands, but even more importantly by the
fact that these glands are also complex secretory
organs6.
If the scent of the hairpencils is distributed
adhering to a dust-like material, as it almost cer-
tainly is in some species (and perhaps in all, see
sections IV-C and D), then another possibility
exists. It may well be (5) that the odor has a
high evaporation rate which is lowered by chemi-
cally combining with a wing gland secretion.
This would allow the gradual release of the scent
from the dust which fell on the antennae of the
female and so prolong its effect during the criti-
cal final phases of courtship when the hairpencils
are withdrawn. Blum & Traynham (1960) put
forward a similar hypothesis to explain the ex-
istence of two secretory components in the de-
fensive glands of the pentatomid bug Oebalus
pugnax (Fab.). Presumably one is the active
product and the other slows its rate of evapora-
tion and so lengthens the life of the defensive
secretion in the area where it has been ejected.
Alternatively, (6) the different secretions may
combine chemically7 as a third product which
6As pointed out in section IV-D, Urquhart is incorrect
in his histological interpretation that the wing gland is a
scent receptor. Furthermore, based on our experience in
removing hairpencils for chemical analyses, the hairpen-
cil “fluid” which he experimentally observed being “ab-
sorbed” by the wing gland is the yellow hemolymph of
the butterfly squeezed out through the ruptured stalk of
the hairpencil and is certainly not the hairpencil secre-
tion.
tBrower & Jones (1965) have produced two lines of
evidence supporting a chemical interaction of the glands
in the Trinidad Queen. Wing pockets of reared males
were sealed from birth, and 5 days later the hairpencil
scent was of a different quality and lower intensity than
in a series of control males. Wild individuals of various
ages were similarly treated and 7 days later the scent of
their hairpencils was found to have diminished both in
strength and fragrance compared to control males.
1965]
Brower, Brower & Cranston: Courtship Behavior of Queen Butterfly
33
has greater stimulative power than either alone.
This hypothesis was also originally suggested by
Eltringham (1929) for the males of a brassolid
butterfly which has two different kinds of ab-
dominal glands. In his words, “whether these
two separate organs give rise to different scents
at different times, (hypothesis 3 of the present
paper ] or whether their volatile products com-
bine in the air to produce a single effect, we do
not know” ( p. 1 ) . He later (1935) extended the
idea of a combined product to Euploea core
asela. Recent biochemical studies have demon-
strated that certain insects do produce and store
secretions in different organs and then mix them
to produce a third product. For example, the
miniature explosions of the Bombadier beetles
of the genus Brachinus result from a mixture of
chemicals (Schildknecht & Holoubek, 1961).
Another example is seen in the cockroach, Peri-
planeta americana Linnaeus. The female of this
species has paired lateral abdominal glands, one
of which produces an enzyme and the other a
substrate. When these are released inside the
reproductive duct of the female, an organic acid
is formed which tans the cuticle of the oothecum
(Brunet & Kent, 1955).
Finally (7) the wing gland secretion may
serve only as a preening substance for the hair-
pencils.
Thus it can be seen that the functional rela-
tionship of the hairpencils and wing glands in
these butterflies has still to be solved. Fortu-
nately, the analytical tools are now available to
do this, and it is hoped that work in progress
(Brower, Eisner & Meinwald) will shed more
light on this fascinating problem.
(F.) Speculation
If it can be demonstrated experimentally that
the male sex perfume of the Danainae functions
biologically as an arrestant pheromone of the
female’s flight, then a whole new field of evolu-
tionary biochemistry will be opened. Males of
one species would be able to arrest their own
females but might not be able to arrest those of
other species. In other words, each species may
have its own chemical language. Moreover, if
the active arresting principles for a series of
species can be chemically characterized, it may
be possible to reconstruct how changes at a mo-
lecular level have resulted in the evolution of a
sexual isolating mechanism. Hybridization stud-
ies could then be made to gain an understanding
of the hereditary basis of the changes, and com-
parisons of subspecies and populations from
various parts of dines would yield knowledge of
how this chemical evolution occurs in nature.
It is, however, well to remember that the hair-
pencilling behavior is only part of the whole
courtship sequence of these butterflies. Conse-
quently, as in the sex attractants produced by
female saturniid moths (Schneider, 1962; Wil-
son & Bossert, 1963), the chemical specificity
may not be a simple lock and key mechanism.
VIII. Summary
1 . By means of experimentally controlled ob-
servations, it has been possible to describe and
analyze quantitatively the courtship behavior of
the Queen butterfly, Danaus gilippus berenice.
Laboratory- reared females were released singly
to wild Queen males in their natural environ-
ment in southern Florida and the courtship be-
havior was recorded verbally by means of a
transistorized tape recorder. A total of 266 court-
ships of 81 females is analyzed in this paper.
2. The components and phases of successful
courtship are summarized in Table 1 and text-
figure 9, and the reasons for termination of
courtship prior to copulation are in Table 2. The
courtship follows the well-known stimulus-re-
sponse reaction chain. The male pursues the fe-
male, overtakes her in the air and induces her to
alight on available herbage by rapidly brushing
her anterior with two scent-disseminating hair-
pencils which are extruded from the posterior of
his abdomen. If the female is receptive, she ac-
quiesces by folding her wings. The male alights
on the female laterally, attempts to copulate and
palpates her head alternately with his right and
left antenna. Copulation occurs, followed by a
post-copulatory flight in which the male carries
the female to an inconspicuous area where in-
semination takes place over a several-hour per-
iod during which both remain stationary. If the
female is unreceptive during the ground compo-
nent, the male often successfully reinitiates the
entire courtship sequence by fluttering above and
alighting on her dorsum.
3. The relationship of the hairpencil glands to
the wing glands in male Danainae is considered
in detail. On the basis of histological studies,
both organs appear to be actively secretory, but
only the hairpencils are characteristically odor-
iferous. The males push their hairpencils into or
rub them over their wing glands when they are
by themselves, and not engaged in courtships.
Seven hypotheses are discussed: (a) that the
wing glands produce the scent and the hairpen-
cils disseminate it; (b) the reverse; (c) that both
glands produce different active stimulants which
play independent roles in the courtship; (d) that
the hairpencils produce the scent which both
they and the wing glands disseminate at different
times in the courtship; (e) that the wing glands
produce a secretion which reduces the rate of
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Zoologica: New York Zoological Society
[50: 1
evaporation of the hairpencil secretion; (f) that
the two secretions combine as a third product
which has greater stimulating powers than either
alone; and (g) that the wing gland secretion is
a preening substance for the hairpencils. Hypo-
theses (a) -(c) are ruled out, (d) is considered
unlikely and limited evidence supports (f). Fur-
ther work is needed to solve the problem.
4. However, it seems virtually certain that the
hairpencils do disseminate the scent about the
female. This perfume is regarded as a phero-
mone which acts as a chemical arrestant of the
female’s non-specific escape flight from the pur-
suing male. Presumably it also functions to keep
her quiescent after the male has induced her to
alight.
5. If the arrestant perfume is species-specific,
it may be possible to reconstruct how changes at
a molecular level have resulted in the evolution
of a sexual isolating mechanism.
IX. References
Aurivillius, C.
1911. Danaidae. In A. Seitz, The Macrolepidop-
tera of the World. XIII. The African
Rhopalocera. Alfred Kernen, Stuttgart,
1925: 71-80.
Baerends, G. P.
1959. Ethological studies of insect behavior. An-
nual Review of Entomology, 4: 207-234.
Barth, R.
1959. Phylogenetische Betrachtungen der Duft-
apparate einiger Nymphalinae (Lepidop-
tera, Nymphalidae). Academia Brasileira
de Ciencias, Vol. 31, No. 4: 557-565.
1960. Maennliche Duftorgane Brasilianischer
Lepidopteren. 23. Mitteilung Vergleich-
ende Betrachtung der Duftschuppen ver-
schiedener Pieriden. Anais da Academia
Brasileira de Ciencias, 32: 281-298.
Beck, S. D.
1964. Time measurement in insect photoperi-
odism. American Naturalist, 98: 329-346.
Blum, M. S„ & J. G. Traynham
1960. The chemistry of the pentatomid scent
gland. XI Int. Congr. for Entomology,
Vienna, Symposium 3, Vol. 3: 48-52.
Brower, L. P.
1959. Speciation in butterflies of the Papilio
glaucus group. II. Ecological relationships
and interspecific sexual behavior. Evolu-
tion, 13: 212-228.
1961a. Studies on the migration of the monarch
butterfly. 1. Breeding populations of
Danaus plexippus and D. gilippus berenice
in south central Florida. Ecology, 42:
76-83.
1961b. Experimental analyses of egg cannibalism
in the monarch and queen butterflies,
Danaus plexippus and D. gilippus berenice.
Physiological Zoology, 34: 287-296.
1962. Evidence for interspecific competition in
natural populations of the monarch and
queen butterflies Danaus plexippus and D.
gilippus berenice in south central Florida.
Ecology, 43: 549-552.
1963. The evolution of sex-limited mimicry in
butterflies. Symposium on Mimicry, Proc.
XVI Int. Congr. of Zoology, Washington,
D. C. Vol. 4: 173-179.
Brower, L. P., & Iane V. Z. Brower
1964. Birds, butterflies, and plant poisons: a
study in ecological chemistry. Zoologica,
49: 137-159.
Brower, L. P., & Florence P. Cranston
1962. Motion picture film: Courtship behavior
of the queen butterfly, Danaus gilippus
berenice. Pennsylvania State University
Psychological Cinema Register, Film No.
2123K.
Brower, L. P. & Margaret A. Jones
1965. Precourtship interaction of wing and ab-
dominal sex glands in male Danaus butter-
flies. Proc. Ent. Soc. London (A), 40: In
press.
Brunet, P. C. J., & P. W. Kent
1955. Mechanism of sclerotin formation: the
participation of a beta-glucoside. Nature,
175: 819.
Carpenter, G. D. H.
1935. Courtship and allied problems in insects.
Trans. Soc. British Entomology, 2: 115-
135.
Carpenter, G. D. H., & E. B. Poulton
1914. Dr. G. D. H. Carpenter’s observation of
the epigamic use of its anal brushes by the
male Amauris psyttalea, Plotz. Proc. Ent.
Soc. London, 1914: cxi-cxii.
1927. Dr. G. D. H. Carpenter’s observation on
the epigamic use of its anal brushes by the
male Danaida chrysippus, L., in E. Madi,
Uganda. Proc. Ent. Soc. London, 1927:
44.
1929. The courtship of the African danaine but-
terfly Amauris damocles Beauv., f. psyt-
talea, Plotz, again observed by Dr.
G. D. H. Carpenter. Proc. Ent. Soc. Lon-
don, 1929 (4): 93-94.
Champion, H. G., & E. B. Poulton
1930. The protrusion of anal scent-brushes dur-
ing flight by the male Euploea core L.,
observed by H. G. Champion at Dehra
Dur, India. Proc. Ent. Soc. London, 5:
14-15.
Clark, A. H.
1926. Notes on the odor of some New England
butterflies. Psyche, 33: 1-5.
1965]
Brower, Brower & Cranston: Courtship Behavior of Queen Butterfly
35
1927. Fragrant butterflies. Smithsonian Report
for 1926. U. S. Govt. Printing Office,
Washington, pp. 421-446.
1941. Notes on some North and Middle Ameri-
can danaid butterflies. Proc. United States
National Museum, 90: 531-542.
Crane, Jocelyn
1955. Imaginal behavior of a Trinidad butterfly,
Heliconius erato hydara Hewitson, with
special reference to the social use of color.
Zoologica, 40: 167-196.
1957. Imaginal behavior in butterflies of the
family Heliconiidae: Changing social pat-
terns and irrelevant actions. Zoologica,
42: 135-145.
Crane, Jocelyn, & H. Fleming
1953. Construction and operation of butterfly in-
sectaries in the tropics. Zoologica, 38:
161-172.
Davey, K. G.
1960. The evolution of spermatophores in in-
sects. Proc. Royal Ent. Soc. London, (A),
35: 107-1 13.
Davis, J. H.
1943. The natural features of southern Florida;
especially the vegetation, and the Ever-
glades. Geological Bulletin No. 25, Florida
Geological Survey, Florida Department of
Conservation, Tallahassee.
Deevey, E. S., Jr.
1949. Biogeography of the Pleistocene. Bulletin
of the Geological Society of America, 60:
1315-1416.
Dethier, V. G„ L. B. Browne & C. N. Smith
1960. The designation of chemicals in terms of
the responses they elicit from insects.
Jour. Economic Entomology, 53: 134-136.
Dixey, F. A.
1905. [No title]. Proc. Ent. Soc. London, 1905:
liv-lix.
1906a. On epigamic and aposematic scents in
Rhopalocera. British Association, Section
D, York, 1906: abstract, 1 p.
1906b. [No title]. Proc. Ent. Soc. London, 1906:
i-viii.
1911. The scents of butterflies. Royal Institution
of Great Britain. March 3rd, 1911: 1-13.
Ehrlich, P. R.
1958. The integumental anatomy of the monarch
butterfly, Danatts plexippus. Univ. Kansas
Sci. Bull., 38 (2): 1315-1349.
Eltringham, H.
1913. On the scent apparatus in the male of
Amauris niavius Linn. Trans. Ent. Soc.
London, 1913: 399-406. 1 plate.
1915. Further observations on the structure of
the scent organs in certain male danaine
butterflies. Trans. Ent. Soc. London, 1915:
152-176. xi-xx plates.
1923. Butterfly Lore. Clarendon Press, Oxford.
180 pp.
1925. On the abdominal glands in Heliconius
(Lepidoptera). Trans. Ent. Soc. London,
1925: 269-275.
1929. On the scent organs of Opsiphanes cassiae
lucullus Fruhst. (Lepidoptera; Brasso-
lidae). Trans. Ent. Soc. London, 77: 1-4,
1 pi.
Fisher, R. A., & E. B. Ford
1928. The variability of species in the Lepidop-
tera, with reference to abundance and sex.
Trans. Ent. Soc. London, 1928 (pt. II):
367-384.
Flint, R. F.
1957. Glacial and Pleistocene Geology. John
Wiley, New York, xiv + 553 pp.
Forbes, W. T. M.
1939. Revisional notes on the Danainae (Lepi-
doptera). Entomologica Americana, 19
(new series) : 101-140.
Ford, E. B.
1962. Butterflies, 3rd Edn., reprinted. The New
Naturalist Series, Collins, London.
Freiling, H. H.
1909. Duftorgane der weiblichen Schmetterlinge
nebst Beitragen zur Kentniss der Sinnes-
organe auf dem Schmetterlingsfliigel und
der Duftpinsel der Mannchen von Danais
und Euploea. Zeit. F. Wiss. Zoologie
(1909), 92: 210-290. pis. 12-17.
Fruhstorfer, H.
1910. Danaidae. In A. Seitz, The Macrolepidop-
tera of the World. IX. The Rhopalocera
of the Indo-Australian Faunal Region.
Alfred Kernen, Stuttgart, 1927: 191-284.
Fyson, D. R., & E. B. Poulton
1930. Mrs. D. R. Fyson’s observations of the
epigamic behaviour of the male danaine
butterfly Euploea core L. in Madras. Proc.
Ent. Soc. London, 5: 48-49.
Gotz, B.
1951. Die Sexualduftstoffe an Lepidopteren. Ex-
perientia, 7 (11): 406-418.
Haensch, R.
1909. Danaidae. In A. Seitz, The Macrolepidop-
tera of the World. V. The American Rho-
palocera. Alfred Kernen, Stuttgart, 1924:
113-171.
Hausman, Sibyl A.
1951. The scent-producing organ of the male
monarch butterfly. American Naturalist,
85: 389-391.
36
Zoologica: New York Zoological Society
[50: 1
Illig, K. G.
1902. Duftorgane der mannlichen Schmetter-
linge. Zoologica (Stuttgart), 38: 1-34, 5
col. pis.
Karlson, P., & A. Butenandt
1959. Pheromones (ectohormones) in insects.
Annual Review of Entomology, 4: 39-58.
Kaye, W. J.
1921. A catalogue of the Trinidad Lepidoptera.
Rhopalocera (butterflies). Memoirs Dept.
Agriculture Trinidad and Tobago, No. 2,
163 pp.
Lam born, W. A.
1921. An oriental danaine butterfly brushing the
brands on its hindwings. Proc. Ent. Soc.
London, 1921: xcv.
Lamborn, W. A., F. A. Dixey & E. B. Poulton
1912. Amauris egialea stroking the brands of the
hindwings with its anal tufts. Proc. Ent.
Soc. London 1912: xxxiv-xxxvii.
Lamborn, W. A., G. B. Longstaff & E. B. Poulton
1911. Instances of mimicry, protective resem-
blance, etc., from the Lagos District. Proc.
Ent. Soc. London, 1911: xlvi-xlvii.
Lamborn, W. A., & E. B. Poulton
1913. Amauris egialea stroking the brands of the
hindwings with its anal tufts, again ob-
served by W. A. Lamborn. Proc. Ent. Soc.
London, 1913: lxxxiii-lxxxiv.
1918. The relation of the anal tufts to the brands
of the hindwings observed and the scent
perceived in a male Danaine butterfly by
W. A. Lamborn. Proc. Ent. Soc. London,
1918: clxxii-clxxiv.
Latter, O. H., & H. Eltringham
1935. The epigamic behaviour of Euploea
(Crastia) core asela (Moore) (Lepidop-
tera, Danainae), with a description of the
structure of the scent organs. Proc. Roy.
Soc. London, B (No. 806): 470-482.
Lederer, G.
1960. Verhaltensweisen der Imagines und der
Entwicklungsstadien von Limenitis Camilla
Camilla L. (Lep. Nymphalidae). Zeits. f.
Tierpsychologie, 17: 521-546.
Longstaff, G. B.
1905. Notes on the butterflies observed in a tour
through India and Ceylon, 1903-1904.
Trans. Ent. Soc. London, 1905: 61-144.
1908. Bronomic notes on butterflies. Trans. Ent.
Soc. London, (1908): 607-673.
1912. Butterfly hunting in many lands. Long-
mans, Green, London. 728 pp.
1914. Further notes on scents in butterflies.
Entomologists’ Monthly Magazine (2nd
series), 25: 1-8.
Magnus, D. B. E.
1950. Beobachtungen zur Balz und Eiablage des
Kaisermantels Argynnis paphia L. (Lep.
Nymphalidae). Zeits. f. Tierpsychologie,
7; 435-449.
1958. Experimental analysis of some “overop-
timal” sign-stimuli in the mating behaviour
of the fritillary butterfly Argynnis paphia
L. (Lepidoptera: Nymphalidae). Proc.
Xth International Congress of Entomol-
ogy, Vol. 2, 1956: 405-418.
1963. Sex limited mimicry. II— Visual selection in
the mate choice of butterflies. Symposium
on Mimicry, Proc. XVI International Con-
gress of Zoology, Washington, D. C , Vol.
4: 179-183.
Marshall, G. A. K.
1902. Miscellaneous observations on South Af-
rican insects. Trans. Ent. Soc. London,
1902: 538-540.
Muller, F.
1877a. On hair-tufts, felted patches, and similar
structures on the wings of male Lepidop-
tera. lenaische Zeitschrift fur Naturwissen-
schaft, 11: 99-114. In G. B. Longstaff,
1912, Butterfly hunting in many lands
(English translation). Longmans, Green &
Co., London, pp. 604-615.
1877b. On the sexual spots of the males of Danais
erippus and D. gilippus. Archivos do
Museo Na'cional do Rio de Janeiro, 2:
25-29. In G. B. Longstaff, 1912, Butterfly
hunting in many lands (English transla-
tion). Longmans, Green & Co., London,
pp. 616-619.
1877c. The scent-scales of the male “Maracuja
Butterflies.” Kosmos, 1: 391-395. In G. B.
Longstaff, 1912, Butterfly hunting in many
lands (English translation). Longmans,
Green & Co., London, pp. 655-659.
1878. Notes on Brazilian entomology. Trans.
Ent. Soc. London, 1878: 21 1-223.
Norris, Maud J.
1932. Contributions towards the study of insect
fertility. 1. The structure and operation of
the reproductive organs of the genera
Ephestia and Plodia (Lepidoptera, Phyci-
tidae). Proc. Zool. Soc. London, 1932:
595-611, 5 pis.
Petersen, B., & O. Tenow
1954. Studien am Rapsweissling und Bergweiss-
Iing ( Pieris napi L. und Pieris bryoniae
O.). Zoologiska Bidrag Fran Uppsala, 30:
169-198.
Petersen, B., O. Tornblom & N. O. Bodin
1952. Verhaltensstudien am Rapsweissling und
Bergweissling ( Pieris napi L. und Pieris
bryoniae Ochs.). Behaviour, 4: 67.
1965]
Brower, Brower & Cranston: Courtship Behavior of Queen Butterfly
37
PlTTENDRIGH, C. S., & V. S. BRUCE
1959. Hypothesis of an independent internal
timer for daily rhythms. In Photoperiod-
ism and related phenomena, ed. R. B.
Withrow. A.A.A.S., 1959: 475-505.
Poulton, E. B.
1906. [No title], Proc. Ent. Soc. London, 1906:
7-8.
1907. Protective substances in male scent-glands.
Proc. Ent. Soc. London, 1907: x-xi.
1927. The scents of butterflies. J. Darjeeling
Natural History Soc., 2: 47-54.
1929. Wild birds and butterflies. Nature, 124:
577-578.
PUNNETT, R. C., & E. B. POULTON
1927. Note by Professor R. C. Punnett, F.R.S.,
on the courtship of a danaine butterfly
in Ceylon. Proc. Ent. Soc. London, 1927:
44-45.
Pycraft, W. P.
1939. Some of nature’s “perfumers.” Illustrated
London News, 21 January, 1939. p. 96.
Richards, O. W.
1927. Sexual selection and allied problems in
the insects. Biological Reviews, 2: 298-
364.
Rothschild, Miriam
1961. Defensive odours and Mullerian mimicry
among insects. Trans. Roy. Ent. Soc. Lon-
don, 113: 101-121.
SCHILDKNECHT, H„ & K. HOLOUBEK
1961. Die Bombardierkafer und ihre Explosions-
chemie. V. Mitteilung fiber Insekten-Ab-
wehrstoffe. Angew. Chem., 73: 1-7.
Schneider, D.
1962. Electrophysiological investigation on the
olfactory specificity of sexual attracting
substances in different species of moths.
Jour. Insect Physiology, 8: 15-30.
Scudder, S. H.
1889. The Butterflies of the Eastern United
States and Canada. 3 vols., 1,958 pp. Cam-
bridge, Mass. Published by the author.
Seitz, A.
1908. Danaidae. The Macrolepidoptera of the
World. I. The Macrolepidoptera of the
Palaearctic Fauna. Alfred Kernen, Stutt-
gart, 1909: 75-78.
Sevastopulo, D. G„ & G. D. H. Carpenter
1944. Note on the courtship of Euploea core
core Cr. (Lep. Danaidae). Proc. Roy. Ent.
See. London, (A), 19: 138-139.
Stride, G. O.
1956. On the courtship behaviour of Hypolimnas
misippus L., (Lepidoptera, Nymphalidae),
with notes on the mimetic association with
Danaus chrysippus L., (Lepidoptera, Dan-
aidae). British Jour, of Animal Behaviour,
4: 52-68.
1957. Investigations into the courtship behav-
iour of the male of Hypolimnas misippus
L. (Lepidoptera, Nymphalidae), with spe-
cial reference to the role of visual stimuli.
British Jour, of Animal Behaviour, 5 : 153-
167.
1958a. Further studies on the courtship behaviour
of African mimetic butterflies. Animal Be-
haviour, 6: 224-230.
1958b. On the courtship behaviour of a tropical
mimetic butterfly, Hypolimnas misippus
L. (Nymphalidae). Proc. Xth Interna-
tional Congress of Entomology, Vol. 2,
1956: 419-424.
Talbot, G.
1947. The Fauna of British India, including Cey-
lon and Burma. Butterflies, Vol. II. Taylor
and Francis, Ltd., London. 506 pp.
Tinbergen, N.
1951. A Study of Instinct. Clarendon Press, Ox-
ford. 228 pp.
Tinbergen, N., B. J. D. Meeuse, L. K. Boerema
& W. W. Varossieau
1942. Die Balz des Samtfalters, Eumenis ( =
Satyrus) semele (L.) Zeits. f. Tierpsycho-
logie, 5 : 182-226.
Urquhart, F. A.
1958. Scent receptors in Lepidoptera. Contribu-
tions of the Royal Ontario Museum of
Zoology and Palaeontology, No. 49; pp.
1-16 (April 22, 1958).
1960. The Monarch Butterfly. Univ. Toronto
Press, xxiv +361 pp.
Wheeler, L. R.
1946. Sex brands in ldeopsis gaura, race pera-
kana, Fruh. (Danaidae). Entomologist’s
Record, Dec. 1946: 149-150.
Wilson, E. O., & W. H. Bossert
1963. Chemical communication among animals.
Recent Progress Hormone Research, 19:
673-716.
Wood-Mason, J., & L. De Niceville
1886. The Rhopalocera of Cachar. J. Asiatic
Soc. Bengal, 1886, Vol. XV. Pt. 2, No. 4:
343-393.
38
Zoologica: New York Zoological Society
[50: 1
EXPLANATION OF THE PLATES
Plate I
Fig. 1. Dorsal view of the posterior of a male
Danaus gilippus berenice showing the left
and right wing pockets and the tip of the
abdomen. The hairpencils are in their re-
tracted position.
Fig. 2. Dorsal view of the posterior of the ab-
domen and right hindwing of a male D. g.
berenice with the hairpencils about 75%
extruded, hp = hairpencil; shp = par-
tially evaginated membranous sheath of
the hairpencil; wp = right wing pocket;
owp = opening of the wing pocket
through which the hairpencil is inserted.
Fig. 3. Hairpencils of D. g. xanthippus fully ex-
truded and splayed. The individual hairs
arise from the glandular base (gbhp) of
the hairpencil (see Plate VI, fig. 1) which
is here shown completely evaginated; shp
= fully evaginated membranous sheath of
the hairpencil.
Fig. 4. Hairpencils of D. g. berenice about 75%
extruded.
Plate II
Figs. 1 and 2. A male D. g. xanthippus ground hair-
pencilling (phase 3) the female after hav-
ing induced her to alight on herbage. In
Fig. 1, the hairpencils (hp) are fully
splayed, whereas in Fig. 2, they are only
partially splayed.
Figs. 3 and 4. Two consecutive slow motion (64
f.p.s.) photographs of a D. g. berenice
male ground hairpencilling the female
(phase 3). In Fig. 3, the hairpencils (hp)
are partially extruded from the abdomen
(abd) which has begun to sweep down
across the head and antennae of the
female. In Fig. 4, 16 microseconds later,
the abdomen has completed the sweep; the
hairpencils are obscured by foliage.
Plate III
Fig. 1. A male D. g. xanthippus hairpencilling the
female in the air (phase 2). The posterior
of the male is between the open wings of
the female so that the extruded hairpencils
are not visible. Both butterflies are flying
rapidly towards the left.
Fig. 2. A male D. g. xanthippus , with hairpencils
retracted, hovering above the female
(phase 4). She clings to herbage, holding
her wings outspread in an unreceptive
position.
Fig. 3. A male D. g. xanthippus attempting to
copulate (phase 5) with the female from
the right lateral position. Note that the
male clings to the undersurface of the
female’s wings with his legs, while she
holds onto the herbage, her wings folded
dorsally in the receptive position. The
male’s abdomen is thrust up between the
hindwings of the female.
Fig. 4. A male D. g. xanthippus terminating an
unsuccessful courtship by desertion.
Plate IV
Fig. 1. Copulating pair of D. g. berenice with the
male clinging to herbage and holding the
female upside down at the end of his ab-
domen.
Plate V
Fig. 1. Male Lycora ceres ceres held in forceps,
showing the large hairpencils spontaneous-
ly splayed to the full extent. The left hair-
pencil is partially hidden from view by the
right one.
Plate VI
Fig. 1. Median longitudinal section through the
glandular base of the hairpencil of a 15-
minute post-emergent male D. g. berenice,
H and E, 100 X. se = trichogen secretory
cell; ih = individual hair of the hairpencil
originating in a trichogen cell; rm = re-
tractor muscle of the hairpencil; d =
globular secretion (“dust”) between the
hairs.
Fig. 2. Globular secretion (“dust”) between the
hairs of a 3-day post-emergent D. g. bere-
nice male, H and E, 400 X.
Plate VII
Fig. 1. Median transverse section through the
right wing pocket of a 10-minute post-
emergent D. g. berenice male, showing
how the pocket develops, H and E, 50 X.
uwm = unmodified wing membrane; Cu2
= second cubitus vein of the hindwing;
fowp = future opening to the lumen of
the wing pocket; f lumen = future lumen
of the wing pocket; fcwp = future cover
of the wing pocket; A = trichogen secre-
tory cells before expanding to fill nearly
the entire space between A and B.
1965]
Brower, Brower & Cranston: Courtship Behavior of Queen Butterfly
39
Fig. 2. Median transverse section through the ma-
ture left wing pocket of a 24-hour post-
emergent male D. g. berenice, H and E,
100X. uwm = unmodified wing mem-
brane; (Cu2 is not shown); owp = open-
ing to the lumen of the wing pocket
through which the hairpencil insertion oc-
curs; A = fully expanded trichogen secre-
tory cells nearly filling the space between
A and B; sc = individual trichogen secre-
tory cell; is — individual specialized flat
scales originating in respective trichogen
secretory cells. Note that the flat scales are
oriented in the direction offering the least
resistance to the insertion of the hairpencil.
Fig. 3. Dorsal view of a wing pocket of a 15-
minute post-emergent male D. g. xanthip-
pus prior to the folding over of the cover
to form the pocket. Cu2 = second cubitus
vein of the hindwing; fcwp = future cover
of the wing pocket; fowp = region of the
future opening to the lumen of the wing
pocket.
Fig. 4. Dorsal view of a wing pocket of a 24-
hour post-emergent male D. g. xanthippus
showing the mature organ. Cu2 = second
cubitus vein of the hindwing; cwp = cover
of the wing pocket; owp = region of the
opening to the lumen of the wing pocket.
The photographs for Plate I, Figs. 1 and 2, and
Plate IV are by Lee Boltin, and the remaining
photographs are by the authors and M. A. Jones.
BROWER. BROWER & CRANSTON
PLATE I
FIG. 2
FIG. 3
FIG. 1
FIG. 4
COURTSHIP BEHAVIOR OF THE QUEEN BUTTERFLY. DANAUS GILIPPUS BERENICE
BROWER, BROWER & CRANSTON
PLATE II
FIG. 2
FIG, I
FIG. 3
FIG. 4
COURTSHIP BEHAVIOR OF THE QUEEN BUTTERFLY, DANAUS GILIPPUS BERENICE
BROWER, BROWER & CRANSTON
PLATE III
FIG. 1
FIG. 3
FIG. 2
FIG. 4
COURTSHIP BEHAVIOR OF THE QUEEN BUTTERFLY, DANAUS GILIPPUS BERENICE
BROWER. BROWER & CRANSTON
PLATE IV
FIG. 1
COURTSHIP BEHAVIOR OF THE QUEEN BUTTERFLY, DANAUS GILIPPUS BERENICE
BROWER, BROWER a CRANSTON
PLATE V
FIG. 1
COURTSHIP BEHAVIOR OF THE QUEEN BUTTERFLY, DANAUS GILIPPUS BERENICE
BROWER, BROWER & CRANSTON
PLATE VI
FIG, 1
FIG. 2
COURTSHIP BEHAVIOR OF THE QUEEN BUTTERFLY. DANAUS GILIPPUS BERENICE
BROWER. BROWER & CRANSTON
PLATE VI!
COURTSHIP BEHAVIOR OF THE QUEEN BUTTERFLY. DANAUS GILIPPUS BERENICE
2
Observations on the Distribution and Ecology of Barker’s Anole,
Anolis barkeri Schmidt (Iguanidae)
I. P. Kennedy
Department of Anatomy, The University of Texas
Dental Branch, Houston, Texas 77025
(Plate I)
RECENTLY Robinson (1962) reported on
a population of Anolis barkeri living on
the western slopes of Volcan Santa Marta
in the region of “Los Tuxtlas,” Veracruz, Mexico,
at longitude 94°25\ latitude 18°25'. This is ap-
parently the first account of a population of this
anole since the species was described from a sin-
gle specimen by the late Karl P. Schmidt in 1 939.
Smith & Taylor ( 1950) recorded Anolis barkeri
only from the type locality of Cascajal, upper
Uzpanapa River, Veracruz. During a recent stay
in Catemaco, Veracruz, in the Tuxtlas, I jour-
neyed to Volcan Santa Marta for the purpose of
making observations on the ecology of this
poorly known, semi-aquatic anole, and those ob-
servations are reported here.
Distribution
Two specimens of A. barkeri were collected in
a preliminary visit to Volcan Santa Marta on
June 8, and the days and nights of June 22 and
23, 1964, were spent in collecting at this locality.
Four anoles were collected on June 22 and one
on the morning of June 23. Two were misplaced
in transit and one disintegrated in an experi-
mental fixative. Of the remaining four speci-
mens, three have been placed in the collection of
Arlington State College Vertebrate Museum and
one was sent to Dr. Carmona y Valle of the
Institute Nacional de Investigaciones Biologico-
Pesqueras, Mexico, D.F., in accordance with the
collecting permit issued by the Mexican govern-
ment.
In addition to the specimens cited by Robinson
(1962), at least 12 specimens of Anolis barkeri
are known that represent additional localities in
southern Mexico. Noteworthy are those that ex-
tend the range into the state of Oaxaca. Because
these specimens add considerably to the previous
distributional records they are listed here.
Veracruz. University of Illinois Museum of
Natural History Collection No. 40141, Coyame,
about 10 miles east of Catemaco, Veracruz. The
Museum of Natural History of Kansas Nos.
27503-4, 20 kilometers east northeast of Jesus
Carranza.
Oaxaca. University of Illinois Natural History
Collection Nos. 35517-9, 35521-2, from Cerro
Azul, above La Gloria. Museum of Comparative
Zoology No. 58221 from Cerro Azul. American
Museum of Natural History No. 64986, Santa
Maria Chimalapa; Nos. 64985, 64987, Rio
Grande at an altitude of 1,300 feet.
The American Museum specimens were col-
lected along streams. A delimitation of the range
of A. barkeri at this time is certainly premature
but the limited ecological observations which fol-
low suggest a habitat preference for stream mar-
gins which provide favorable temperatures and
boulders for basking. It would not seem unrea-
sonable to expect the species to occur along simi-
lar aquatic habitats in this region of southern
Mexico.
Ecological Observations
Extensive banana plantations occur in the re-
gion of Santa Marta but most of the area that
has not been cleared supports a dense rainforest.
Numerous springs on the upper western slope of
Volcan Santa Marta give rise to many small
streams that course down through the rainforest
to enter a swiftly flowing river. A Kollsman
Type C-12 altimeter measured an altitude of ap-
proximately 1,250 feet at the campsite atop a
steep-cut bank about 25 feet above the river.
Some of the seepages of the western slope form
41
42
Zoologica: New York Zoological Society
[50: 2
only trickles that are covered by ferns and thick
vegetation of the forest floor. Other wider
streams are several inches deep and have small
waterfalls along their course. In the more open
areas through which these wider streams tra-
verse, sunlight penetrates the forest canopy and
warms the exposed boulders that rest in the
stream beds. Anolis barkeri basks on these boul-
ders, usually in close proximity to the water. It
was also observed basking on the boulders along
the periphery of the river where the swift current
is much reduced. One anole was sighted clinging
to a small limb overhanging the water.
June 22 was a bright, sunny day. Basking
anoles were sighted by slowly walking wherever
possible in the beds of the streams and river. My
attention was usually attracted when the lizards
sought concealment. Escape behavior consisted
essentially of darting into the water or into a
crevice beneath a boulder. Those that darted into
the water were usually located in concavities be-
neath the boulders. Some were found resting in
the shallow water that trickles through these
crevices; others were observed clinging to the
underside of the boulders about an inch or so
above the water. The brown body coloration
blends well with the volcanic boulders, especially
when the lizards are wet, and in poorly lighted
situations they were not easily seen. Their mild
temperament is indicated by the fact that none
offered to bite when first seized and would only
bite after some provocation. A nematode was
observed protruding from the mouth of one im-
mediately after capture. It was a mermithid and
it is probable that the anole had just eaten a
grasshopper or similar host in which mermithid
nematodes are normally parasitic. Orthopteran
remains were found in the stomach of one anole.
Information on the nematode was supplied by
Mrs. M. B. Chitwood through the kindness of
Dr. Libbie H. Hyman.
In an attempt to obtain information on the
thermal ecology of this anole, temperatures were
measuied with a quick-reading Schultheis ther-
mometer. Body temperatures were measured by
inserting the bulb of the thermometer into the
cloaca as soon as possible after capture. Air
temperatures were measured by holding the ther-
mometer about a centimeter above the lizard’s
initial resting site. Water temperatures were
measured by holding the thermometer about a
centimeter beneath the surface. Even though the
environmental temperatures recorded by this
method are crude approximations, they show
close agreement with the lizard’s body tempera-
ture (Table I). Mean body temperature ex-
ceeded the mean air temperature of the resting
site by 1.2°C and the mean water temperature
by 2.1°C. Conduction from the surface of the
boulders is probably an important source of body
heat. No anoles were seen resting on these boul-
ders during one of the heavy afternoon rains on
Volcan Santa Marta.
Photographs of live Anolis barkeri are pub-
lished for the first time in Plate I, A, B. The larg-
est A. barkeri that I collected is a male with a
snout-vent length of 98 mm., 172 mm. tail, and
weight of 17.3 grams. Four males have a mean
snout-vent length of 86 mm. (80-98 mm. range)
and a mean weight of 12.2 grams (9.1-17.3
grams). Three females have a mean snout-vent
length of 69 mm. (61-79 mm. range). Snout-
vent length and corresponding weight of two of
the females are 79 mm., 10.2 grams; 61 mm., 5.2
grams.
A 79 mm. snout-vent-length female laid two
eggs on July 7 in the jar in which she was tempo-
rarily restrained. Her weight prior to laying was
10.2 grams, as compared to 7.5 grams after ovi-
position. Dissection of this female revealed that
one of the ovaries contained a well-developed
ovum. It is possible that the two ovaries alternate
in egg production, with multiple clutches per fe-
male each year. Such an ovarian cycle has been
demonstrated by Hamlett (1952), who showed
that in female Anolis carolinensis living near
New Orleans the ovaries alternate quite regu-
larly in continuous and rhythmic egg production.
Egg laying covers a period of four or five months,
with each female laying an egg every two weeks.
The reproductive potential, ovarian cycle and
period of egg laying for A. barkeri are com-
pletely unknown and probably differ consider-
ably from those of the smaller, non-aquatic A.
carolinensis.
Table I. Cloacal and Environmental Temperatures of Anolis barkeri.
Snout-vent
Cloacal
Air
Water
Length
Temperature
Temperature
Temperature
Number
Mean (Range)
Mean (Range)
Mean (Range)
Mean (Range)
mm.
°C
°C
°C
7*
78.7 (61-98)
24.4 (22.0-26.8)
23.2 (22.2-24.2)
22.3 (21.6-24.2)
♦Two of the seven anoles were being splashed by water when initially sighted and no air temperature is listed.
1965]
Kennedy: Distribution and Ecology of Barker's Anole
43
The eggs of A. barkeri are light cream-colored
ellipsoids (Plate I, C). Measurements of the two
eggs are: 17.0 X 9.7 mm., 1.1 grams; 17.2 X 9.5
mm., 1.0 grams. A 67 mm. snout-vent-length fe-
male contained an oviducal egg that measured
13x9 mm. and an ovarian egg of approximately
7 mm. in greatest diameter. The only other meas-
urement of eggs of A. barkeri is that of a pre-
served uterine egg which measured 17.3 X 9.2
mm. and was covered with fibrous striations
(Robinson, 1962) . The two eggs laid by the cap-
tive anole above were smooth in appearance
upon gross inspection. The manner in which the
eggs are deposited and the nesting site in nature
are unknown. Adaptations for incubation in the
moist humid environment of the rainforest are
to be expected.
Acknowledgments
I am deeply indebted to Dr. William F. Py-
burn and Mr. William E. Turner of Arlington
State College for much assistance in the field
and especially to Dr. Pyburn for driving me from
Playa Azul on Lake Catemaco to Volc6n Santa
Marta. Dr. Hobart M. Smith generously sup-
plied me with locality data for additional mu-
seum specimens of A. barkeri. Miss June More-
land greatly assisted in the preparation for my
studies in Veracruz, which were supported by a
grant (GU-482-A) from the National Science
Foundation to The University of Texas Dental
Branch.
Summary
Limited observations on the ecology and be-
havior of Anolis barkeri Schmidt were made in a
rainforest in southern Veracruz, Mexico. Anolis
barkeri is a semi-aquatic anole showing a habitat
preference for stream margins which provide
favorable temperatures and boulders for basking.
A mean cloacal temperature of 24.4°C was re-
corded for 7 anoles. Photographs of live A. bark-
eri and eggs of the species are published for the
first time. Locality records of additional speci-
mens in museums extend the range into southern
Oaxaca.
Literature Cited
Hamlett, George W. D.
1952. Notes on breeding and reproduction in the
lizard Anolis carolinensis. Copeia, 1952
(3): 183-185.
Robinson, Douglas C.
1962. Notes on the lizard Anolis barkeri
Schmidt. Copeia, 1962 (3): 640-642
Schmidt, Karl P.
1939. A new lizard from Mexico with a note on
the genus Norops. Zool. Ser. Field Mus.
Nat. Hist., 24 (2): 7-10.
Smith, Hobart M., & Edward H. Taylor
1950. An annotated checklist and key to the
reptiles of Mexico exclusive of the snakes.
Bull. U. S. Nat. Mus. No. 199: 1-253.
44
Zoologica: New York Zoological Society
[50: 2: 1965]
EXPLANATION OF THE PLATE
Plate I
Lateral view of Anolis barkeri Schmidt. A. Female
79 mm. snout-vent, 98 mm. tail, 10.2 grams. B.
Male 85 mm. snout-vent, 87 mm. tail (incomplete),
12.2 grams. C. Two eggs laid by the above female.
KENNEDY
PLATE I
C
OBSERVATIONS ON THE DISTRIBUTION AND ECOLOGY OF BARKER'S ANOLE,
ANOLIS BARKERI SCHMIDT (IGUANIDAE)
3
Underwater Calls of Leptonychotes (Weddell Seal)1 2
William E. Schevill & William A. Watkins
Woods Hole Oceanographic Institution ,
Woods Hole, Mass.
(Plate I)
THAT the Antarctic seal Leptonychotes
weddelli (Lesson) 1826 produces a var-
iety of calls underwater has been known
at least since E. A. Wilson’s account (1907, pp.
12, 14, and especially 16). He described the calls
graphically, recounted hearing the seals calling
beneath the ship as well as beneath the ice, and
supposed that the calls were communicative. Un-
fortunately his observations have been missed
by later workers, including the senior author
(Schevill, Backus & Hersey, 1962, p. 549). More
recent observers have seemed reluctant to con-
sider that the calls were made underwater, and
presumed that the seals were calling in air
trapped under the ice; for example, Lindsey
1937, pp. 139, 143 (though (pers. comm., 1951 )
he helieved that some of the calls were made
submerged), and Perkins, 1945, p. 278. Lindsey
recorded the in-air calls phonographically in
November, 1934; his record was not published,
but he has generously supplied copies of it to in-
terested students. In October and November,
1963, underwater recordings were made at
McMurdo Sound in the Ross Sea by Dr. Carleton
Ray of the New York Zoological Society and
Lt. David Lavallee, USN, using a Brush AX 58 C
hydrophone and a Uher (Report 4000) tape
recorder.
Since a seal calling with its head out of water
is audible to an immersed hydrophone, in-air
calls are also on the tapes. Some of these barks
or howls have fundamental frequencies between
50 and 400 cps with strong harmonic structure,
and last from !4 to 1 second.
Contribution No. 1527 from the Woods Hole Ocean-
ographic Institution.
-This work was supported by Contract Nonr 4029 be-
tween the Office of Naval Research and the Woods Hole
Oceanographic Institution.
The underwater sounds are impulsive. Some-
times they are made at such long intervals that
they might almost be called solitary, but charac-
teristically they occur in series, some of which
lasted as long as 42 seconds. These series begin
with high frequencies (between 1 and 10 kcps,
but usually 1 or 2 kcps) and a high repetition
rate (too high to be separated on these tapes,
with about 120-140 per second, the highest easily
read, as much as 5 seconds after the start of the
series); the frequency and repetition rate drop
gradually during a series, ending as low as 50
cps at a 1 second repetition rate. Lindsey (pers.
comm.) compared this sort of call to a reversed
recording of a ruffed grouse ( Bonasa umbellus)
drumming. Pulse duration varies from .005 to 1.5
seconds, the latter being the most isolated pulses,
and increases with the repetition interval. The
pulses are often a much as 40 db above back-
ground, and may be double or triple; that is,
they may have two or three components, and in
this case, of successively lower frequencies;
pulses at high repetition rates appear single.
Individual pulses as well as components of
multiple pulses are generally of distinct and de-
scending frequency; the first of each multiple
pulse is the highest. Harmonics are sometimes
noted, but may be a feature of the recording and
not of the actual sound. The average frequency
drop within each pulse is as follows:
2000 cps at 10000 cps
1000 4000
100 300
50 100
Each succeeding pulse starts a little lower in fre-
quency than the preceding ones.
Calls of both types, pulses and howls, are in
Lindsey’s 1934 record. He notes (1937, p. 143)
that the calls heard under the ice, resembling the
45
46
Zoologica: New York Zoological Society
[50: 3: 1965]
underwater ones on Ray and Lavallee’s tapes,
were made with the mouth shut, while others,
including “bellowings, roars, and moans,” were
made with the mouth open.
References
Lindsey, Alton A.
1937. The Weddell seal in the Bay of Whales,
Antarctica. Journ. Mammalogy, 18, 2, pp.
127-144.
Perkins, J.
1945. Biology at Little America III . . . Proc.
American Philos. Soc., 89, pp. 270-284.
Schevill, W. E., R. H. Backus & J. B. Hersey
1962. Sound production by marine animals. The
Sea, ideas and observations . . . , M. N.
Hill, ed., vol. 1, ch. 14, pp. 540-566. Wiley
(Interscience), N. Y., London.
Wilson, Edward A.
1907. Mammalia (whales and seals). National
Antarctic Exped., 1901-1904, Natural His-
tory, 2 (Zool.), pp. 1-66, ills.
EXPLANATION OF THE PLATE
Plate I
Fig. 1. Underwater pulses produced by Leptony-
chotes weddelli. This 2-second excerpt oc-
curred 10 seconds after the beginning of
a pulse series which lasted about 25 sec-
onds. A 200-cps analyzing filter bandwidth
was used.
kcps
SCHEVILL & WATKINS
PLATE I
UNDERWATER CALLS OF LEPTON YCHOTES (WEDDELL SEAL)
4
Pulmonary and Cutaneous Gas Exchange in the
Green Frog, Rana clamitans 1
Allen Vinegar2 & Victor H. Hutchison
Department of Zoology, University of Rhode Island,
Kingston, Rhode Island
(Text-figures 1-4)
THE Amphibia have developed several
respiratory mechanisms which occur in
various combinations: branchial, bucco-
pharyngeal, pulmonary and cutaneous. Krogh
( 1904) performed the first quantitative study of
pulmonary and cutaneous respiration in amphib-
ians on the European frogs Rana esculenta and
R. temporaria. Pulmonary respiration was sepa-
rated from cutaneous respiration by cannulating
the lungs. The cannula was then connected
through a stopper in the respiration chamber to
a system of circulating air separate from the one
in which cutaneous respiration was taking place.
Air was pumped mechanically into the lungs at
regular intervals. Similar techniques were used
by Dolk & Postma (1927) on R. temporaria.
These works showed that cutaneous oxygen up-
take remained relatively constant throughout the
year. Pulmonary oxygen uptake was greatest in
the spring and minimal during the fall and win-
ter. Pulmonary and cutaneous carbon dioxide
release showed the pattern of high release in the
spring and low in the fall and winter with the
greatest percentage of release being through the
skin at all times. Two experimental errors were
introduced into the above works. First, the ani-
mals were not acclimated to constant tempera-
ture and photoperiod and second, artificially
pumping air in and out of the lungs did not allow
the frogs to carry on their normal breathing
movements (Scholten, 1942; Cherian, 1958).
In the United States, Whitford & Hutchison
iSupported by National Science Foundation Grants
G-13953 and GB-1368 (to V. H. H.) and a Sigma
Xi-RESA Grant-in-aid (to A. V.3.
^Present address: Department of Reptiles, New York
Zoological Park, Bronx, New York 10460.
(1963, 1965, MS) improved the methods of
measuring gas exchange and acclimating the ani-
mals in their work on several species of sala-
manders. The present study represents the first
application of these improved methods to anuran
respiration. A comparison of respiratory mech-
anisms in frogs and salamanders will give fur-
ther clues to the evolution of respiratory mecha-
nisms in the Amphibia and the relation of these
mechanisms to the habitats of the animals.
Materials and Methods
The animals used for this study were collected
in Washington County, Rhode Island, during
1963. They were acclimated at a constant tem-
perature and photoperiod for at least two weeks
before they were used in an experiment. Accli-
mation temperatures were 5°, 15° and 25°C. The
photoperiods used were 8 and 16 hours (8L16D
= 8 hours of light, 16 hours of dark, and 16L8D
= 16 hours of light, 8 hours of dark, respec-
tively).
Respiration was measured in a closed system
respirometer consisting of four equal-volume
chambers. The animal was placed in one of the
front chambers and a mask of tygon tubing,
which covered the front part of the head without
obstructing the nares, was connected to the other
front chamber through an opening between the
two chambers. Each of the front chambers was
connected through a manometer to a rear cham-
ber which acted as a thermobarometer. The
method is described in more detail by Whitford
& Hutchison (1963) and differs from their de-
scription only in that the carbon dioxide was
absorbed with sodium hydroxide rather than
barium hydroxide. Sodium hydroxide forms a
soluble carbonate, thus eliminating the necessity
47
48
Zoologica: New York Zoological Society
[50: 4
of regularly breaking up the insoluble film of
barium carbonate formed when barium hydrox-
ide is used.
Respiration measurements were determined
for five-hour periods on animals acclimated at
15° and 25 °C, and for 26-hour periods on ani-
mals acclimated at 5°C. The 5° animals were run
for a full day to determine if any daily fluctua-
tions occurred in gas exchange. The decision to
do this was made after the 15° and 25° experi-
ments had been completed. The light and dark
periods at the time of the experiment were the
same as those during the acclimation period. A
red darkroom bulb was used to make the instru-
ment readings during the dark hours.
Results
Pulmonary and Cutaneous Gas Exchange
All values of gas exchange are given in micro-
liters per gram per hour (/d/g/hr). Pulmonary
oxygen consumption increased almost linearly
from 3.20 at 5°C to 60.1 1 at 25°C for 8L accli-
mated animals and linearly from 8.91 at 5°C to
60.06 at 25 °C for 16L animals. Cutaneous oxy-
gen uptake increased slightly from 14.21 to 22.99
for 8L animals and from 11.73 to 21.32 for 16L
animals (Table 1). The ratio of pulmonary to
cutaneous uptake increased with temperature
(Text-fig. 1 ) . A significant difference in the ratio
between 8L and 16L animals is apparent at 5°C
(t = 2.86, p < 0.025). No significant difference
was found at 15° or 25°C.
Pulmonary carbon dioxide release increased
from 1.92 at 5°C to 15.59 at 25°C for 8L ani-
mals and from 1.96 at 5°C to 17.07 at 25°C for
16L animals. Cutaneous carbon dioxide release
increased from 13.02 to 59.25 for 8L animals
and from 16.12 to 55.42 for 16L animals (Table
1 ). The ratio of pulmonary to cutaneous carbon
dioxide release increased only slightly from 5°C
to 25°C (Text-fig. 2). Over 80% of the carbon
dioxide released at all temperatures was through
the skin.
Text-fig. 3 shows the relationship between pul-
monary and cutaneous gas exchange in 16L ani-
mals. A plot of the data for 8L animals would
show the same relationships.
Relationship of Body Weight to Oxygen Uptake
Oxygen uptake is plotted as a function of
weight in Text-fig. 4. The data are plotted at
three temperatures with the 8L and 16L data
combined at each temperature. A regression of
metabolic rate on body weight was determined
at each temperature and the lines plotted on the
same figure. The general equation is M (metab-
olism) = kW (body weight)11 or log M = log
K + n log W. Log K represents the y-intercept
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1965]
Vinegar & Hutchison: Pulmonary and Cutaneous Gas Exchange in Rana clamitans
49
4i> —
4.0 —
Temperature *C
Text-fig. 1. Ratio of pulmonary to cutaneous oxygen uptake at the tempera-
tures and photoperiods indicated. The short vertical line pointing to the
photoperiod represents the mean of the sample. One black and one white
rectangle combined on one side of the mean represents one standard deviation,
and one black rectangle on one side of the mean represents two standard
errors. The long vertical line represents the range of the sample, with short
horizontal lines delimiting the extent of the range. Short lines pointing to
the right delimit 16L ranges and short lines pointing to the left delimit 8L
ranges. If there is no overlap between the black rectangles of two sets of
data, the difference between the means may be considered statistically signifi-
cant (Hubbs & Hubbs, 1953).
and n the slope when the data is plotted log-
arithmically, the equation of the line at 25 °C
was log M = 0.203 + 0.799 log W; at 15°C, log
M = —0.333 + 1.016 log W; at 5°C, log M =
—0.372 + 0.753 log W,
Discussion
In Rana clamitans the additional oxygen re-
quirements at higher temperatures are supplied
by an increase in the rate of pulmonary respira-
tion. Cutaneous uptake is passive and, therefore,
can not supply the additional oxygen needs. The
skin, however, is an important respiratory organ
as over 80% of carbon dioxide release occurs
through the skin at all temperatures.
Photoperiod has been shown to effect such
50
Zoologica: New York Zoological Society
[50: 4
Text-fig. 2. Ratio of pulmonary to cutaneous carbon dioxide release at the
temperatures and photoperiods indicated. The method of presentation is the
same as in Text-fig. 1.
Temperature ®C
Text-fig. 3. Mean pulmonary and cutaneous oxygen uptake and carbon dioxide release for 16L animals
at the temperatures indicated. Each point represents the mean value for all animals at that temperature.
1965]
Vinegar & Hutchison: Pulmonary and Cutaneous Gas Exchange in Rana clamitans
51
Text-fig. 4. Relation of oxygen uptake per hour with weight. Each point
represents the oxygen uptake and weight of a single animal. The regression
lines were obtained by the method of least squares.
phenomena as spring migration and reproduc-
tive cycles in birds, breeding cycles of mammals
and fish and disapause in insects (Withrow,
1959). Hutchison (1961) found seasonal differ-
ences in the critical thermal maximum (CTM)
of the newt, Notophthalmus viridescens. Hutchi-
son suggested that photoperiod is responsible for
the observed seasonal variation in CTM and that
it is likely that the animals react to a changing
ratio of hours of light to hours of dark rather
than to the total number of daylight hours.
Krogh (1904) and Dolk & Postma (1927)
found seasonal variation in the pattern of gas
exchange in Rana temporaria. Fromm & Johnson
(1955) noted a similar pattern in Rana pipiens.
Whitford & Hutchison (1965) found that the
spotted salamander, Ambystoma maculatum at
15°C had a significantly higher rate of oxygen
consumption when acclimated to a 16L photo-
period than when acclimated to a 8L photoper-
iod. This pattern could easily be due to the sea-
sonal changes in photoperiod.
Brown et al. (1955) reported on the occur-
rence in animals and plants of daily rhythms
which persist under conditions of constant dark-
ness and temperature. Many animals maintain
their 24-hour cycle, even when phases of the
cycle have been experimentally shifted from
their normal day-night synchronization to oppo-
site times of light and dark.
Photoperiod significantly affected oxygen up-
take only at 5°C in Rana clamitans in this study.
This does not rule out the possibility that photo-
period has an effect on seasonal oxygen con-
sumption in this animal. The gas exchange of
the animals at 5°C was measured over a period
of 26 hours, while the animals acclimated at 15°
and 25 C were used only for five-hour periods
from 1000 or 1100 hours to 1500 or 1600 hours
(EST). If any daily rhythmicity exists in their res-
piratory pattern, then the comparison of meas-
urements taken at the same time of day for 8L
and 16L acclimated animals might hide the effect
of photoperiod; i. e., metabolism could vary over
52
Zoologica: New York Zoological Society
[50: 4
a 24-hour period but might be the same in any
small segment of time. It would be necessary,
therefore, to measure the metabolism at 15° and
25 °C over a 24-hour period to see if photoperiod
has an effect at these temperatures.
The effect of photoperiod may not be the same
at all temperatures. Hutchison & Kosh (1965)
studied the effect of photoperiod on the CTM ol
painted turtles, Chrysemys picta, acclimated to
10°, 20° and 30°C. Animals acclimated under
16L had a higher CTM than those acclimated
under 8L at all acclimation temperatures. How-
ever, the difference between the 8L and 16L
animals decreased with increasing acclimation
temperature.
The ability of an animal to react to a change
in photoperiod would be a definite advantage
for the animal. An animal responding to an in-
creasing photoperiod in early spring by raising
its metabolic rate would be preadapting itself to
the coming warmer temperatures which further
increase the metabolism of the animal. Thus, an
animal’s physiological responses could become
preadapted to an increase in temperature before
the increase actually occurred.
The value of n in the equation M = kWn (see
explanation of symbols under results) has been
shown to be approximately 0.75 for unicellular
organisms, plants, poikilotherms and homeo-
therms (Hemmingsen, 1960). Tashian & Ray
( 1957) compared oxygen consumption in tropi-
cal frogs with consumption in temperate and
boreal species. The tropical anurans ( Hyla max-
ima, H. crepitans, Leptodactylus typhonius,
Eupemphix pustulosus, Prostherapis trinitatis)
had an n of 0.83 at 25°C and of 0.86 at 10°C.
The temperate and boreal frogs ( Rana sylvatica,
H. crucifer, R. clamitans) had an n of 0.70 at
24°C and 0.71 at 14°C. Cherian (1962) found
n = 0.925 for Rana hexadactyla at 29°C. Thus,
the values of 0.753 and 0.799 obtained for Rana
clamitans in this study at 5° and 25 °C are in
agreement with these other findings. The value
of 1.01 obtained at 15°C is not significant since
the 95% confidence limits on this figure indicate
that the actual value of n falls between 0.56 and
I. 46. Closer confidence limits were not obtained
at 15°C, probably because the metabolism-
weight data were more variable than at 5° or
25°C.
Summary
In Rana clamitans:
1. Pulmonary oxygen uptake becomes increas-
ingly important at higher temperatures.
2. Cutaneous oxygen uptake increases only
slightly with increasing temperature.
3. At all temperatures, over 80% of all carbon
dioxide is released through the skin.
4. Oxygen uptake is significantly affected by
photoperiod only at 5°C, although 24-hour
determinations might find the same effect at
15° and 25°C.
5. The relation between total oxygen uptake and
weight at 5° and 25 °C is the same as has been
found in other frogs.
Literature Cited
Brown, F. A., Jr., H. M. Webb, M. F. Bennett &
M. I. Sandeen
1955. Evidence for an exogenous contribution
to persistent diurnal and lunar rhythmicity
under so-called constant conditions. Biol.
Bull., 109: 238-254.
Cherian, A. G.
1958. Respiratory movements in the frog. Acta
Physiol. Pharmacol. Neerlandica, 7: 420-
424.
1962. Metabolism as a function of age and
weight in frog. Acta Physiol. Pharmacol.
Neerlandica, 1 1 : 443-456.
Dolk, H. E., & N. Postma
1927. fiber die Haut und die Lungenatmung von
Rana temporaria. Zeitschr. vergl. Physiol.,
5: 417-444.
Fromm, P. O., & R. E. Johnson
1955. The respiratory metabolism of frogs as
related to season. J. Cell, and Comp.
Physiol., 45: 343-359.
Hemmingsen, A. M.
1960. Energy metabolism as related to body size
and respiratory surfaces, and its evolution.
Rep. Steno Hosp., Copenhagen, 9 (Part
2): 3-110.
Hubbs, C. L., & C. Hubbs
1953. An improved graphical analysis and com-
parison of series of samples. Syst. Zool.,
2: 49-57.
Hutchison, V. H.
1961. Critical thermal maxima in salamanders.
Physiol. Zool., 34: 92-125.
Hutchison, V. H., & R. G. Kosh
1965. The effect of photoperiod on the critical
thermal maxima of painted turtles
( Chrysemys picta). Herpetologica, 20(4):
233-238.
Krogh, A.
1904. On the cutaneous and pulmonary respira-
tion of the frog. Skand. Arch. Physiol., 15:
328-419.
1965]
Vinegar & Hutchison: Pulmonary and Cutaneous Gas Exchange in Rana clamitans
53
SCHOLTEN, J. M.
1942. A few remarks on the respiratory move-
ments of the frog. Arch. Neerlandica Sci.,
26: 250-268.
Tashian, R. E., & C. Ray
1957. The relation of oxygen consumption to
temperature in some tropical, temperate
and boreal anuran amphibians. Zoologica,
42: 63-68.
Whitford, W. G., & V. H. Hutchison
1963. Cutaneous and pulmonary gas exchange
in the spotted salamander, Ambystoma
maculatum. Biol. Bull., 124: 344-354.
1965. Effect of photoperiod on pulmonary and
cutaneous respiration in the spotted sala-
mander, Ambystoma maculatum. Copeia,
1965 (1) (In press).
(MS) Gas exchange in salamanders. Physiol.
Zool., (In Press).
Withrow, R. B. (Ed)
1959. Photoperiodism and Related Phenomena
in Plants and Animals. Wash., D. C. Amer.
Assoc. Adv. Sci.
5
Evoked Potentials in the Visual Pathway of Heliconius
erato. (Lepidoptera) 1,2
S. L SWIHART
Department of Biology,
New York State University,
Fredonia, New York
(Plates I-III; Text-figure 1 )
[This paper is one of a series emanating from the
William Beebe Tropical Research Station of the
New York Zoological Society, at Simla, Arima Val-
ley, Trinidad, West Indies. The station was founded
in 1950 by the Zoological Society’s Department of
Tropical Research, under Dr. Beebe’s direction. It
comprises 250 acres in the middle of the Northern
Range, which includes large stretches of government
forest reserves. The altitude of the research area
is 500 to 1,800 feet, and the annual rainfall is more
than 100 inches.
[For further ecological details of meteorology
and biotic zones, see “Introduction to the Ecology
of the Arima Valley, Trinidad, B.W.I.,” by William
Beebe, Zoologica, 1952, 37 (13) 157-184.
[The success of the present study is in large mea-
sure due to the cooperation of the staff at Simla,
especially of Jocelyn Crane, Director, who con-
tributed so freely of her knowledge of the organ-
isms studied. The author particularly wishes to
acknowledge the invaluable technical assistance
rendered by Mr. Robert Varnum],
Introduction
It is axiomatic that reactive mechanisms are
dependent upon sensory perception. A logi-
cal extension of this premise is that the na-
ture of behavioral releasers is limited by the ac-
tion spectra of the sense organs. A not so logical
conclusion is that the action spectra of sense
organs, and behavioral releasers, are identical. In
some cases this may be true; particularly in
those situations where a simple sense organ can
resolve only the intensity of the stimulus, rather
Supported by a grant (NSF-GB-2331 ) from the Na-
tional Science Foundation.
Contribution No. 1,069, Department of Tropical
Research, New York Zoological Society.
than its “quality.” Notable exceptions seem pos-
sible in the case of chemoreceptors (Schneider,
1962) and photoreceptors.
While chemical releasers seem to be of pri-
mary importance in nocturnal insects, visual
stimuli dominate the sensory input of most di-
urnal species. Behavioral observations of butter-
flies have confirmed this viewpoint. As Ford
(1945) stated, “being day-flying species, the
male relies more on sight in finding his mate,
though scent may play a small part . . .”
Electrophysiological investigations into the
spectral sensitivity of the insect compound eye
have often produced luminosity curves, based
upon the electroretinogram (ERG), showing a
peak in the blue-green (e.g., Autrum & Stumpf,
1953; Goldsmith, 1960). There are, however, in-
stances when behavioral responses seem to be
specific for stimuli in other portions of the spec-
trum. One such case is the neotropical butterfly
Heliconius erato hydara Hewitson (1869) (see
Kaye, 1921), which has been shown to respond
preferentially to orange-red stimuli in its feed-
ing and courtship behavior (Crane, 1955). Swi-
hart ( 1963) demonstrated that the eye’s sensitiv-
ity, as determined by the electroretinogram,
peaked in the blue-green. Use of criteria other
than the usual ERG B wave indicated the pres-
ence of receptors maximally sensitive to red. A
more detailed analysis (Swihart, 1964) gave fur-
ther indirect evidence for a short latency receptor
maximally sensitive to the blue-green (528 m^i),
and a long latency one peaking in the red (61 6 —
636 m/x).
On the basis of this evidence, it was decided
to attempt to follow the passage of information
55
56
Zoologica: New York Zoological Society
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from the photoreceptors to the brain, in an effort
to determine at what level a special sensitivity
to the color red develops.
Methods and Materials
Equipment for stimulating photically was as
previously described (Swihart, 1963, 1964).
This consisted, basically, of an incandescent
lamp, narrow-band interference filters, a compur
shutter, rotating notched wheel (to provide
flicker) and an optical system which focused a
spot of light 2—3 mm. in diameter on the cornea
of the eye. Stimulus energies were determined
by “grease-spot” photometry using a standard
light source.
Potentials were amplified with Grass P-6 D.C.
amplifiers, displayed on a Tektronix 564, four-
beam storage oscilloscope, and recorded with a
Grass C-4 camera. In all recordings an upward
deflection indicates a negative polarity of the
active electrode.
ERGs were recorded with the aid of steel elec-
trodes with a tip diameter of ca. 15 /x placed
sub-corneally. Other potentials were recorded
with KC1 filled, glass capillary electrodes, with
tip diameters of 1.5 fi to ca. 8 /x.
Since this investigation involved the establish-
ment of the form and relationship of the poten-
tials characteristic of each of the tissues of the
visual pathway, it was arbitrarily decided to
compare all responses to a simultaneously re-
corded ERG. Certain previous efforts in this
area ( e.g ., Burtt & Catton, 1956) had recorded
only potentials resulting from various electrode
positions. In view of the high degree of vari-
ability found in insect visual responses, and their
sensitivity to injury, this technique seemed in-
advisable, since without continuous monitoring
of the ERG one cannot be certain that response
characteristics are maintained.
A second advantage of this technique is that
it affords a simple method for ascertaining the
relative spectral sensitivity of a response by com-
parison vvith the ERG. Thus stimuli of two dif-
erent wavelengths may be adjusted in intensity
so as to produce ERGs of identical size. If the si-
multaneously recorded nervous responses main-
tain a constant magnitude, then one may pre-
sume that the spectral sensitivities of the ERG
and the particular nervous response are probably
identical. If, however, the ERGs are of the same
magnitude, but the nervous responses are signifi-
cantly different in size, it becomes likely that the
nervous response represents the activity of either
receptors, or an integrative process with a spec-
tral sensitivity markedly different than those
processes responsible for producing the ERG.
Several techniques were tried in determining
micro-electrode position. The most satisfactory
was found to be inserting the glass electrode with
a micro-manipulator equipped with a microm-
eter scale. As the electrode was passed through
the head of the intact insect, the depth of pene-
tration was noted. When the “transit” was com-
pleted, the electrode was broken off in situ and
the head dissected under a 70x microscope with
ocular micrometer. Such a dissection could eas-
ily determine the tissues through which the elec-
trode had passed. This could then be correlated
with measurements from the micro-manipulator
to establish the position of the electrode tip at
the time of any given recording.
It should be pointed out that such experiments
were conducted with the electrode penetrating
the head from every practicable direction. In
many cases a dorso-ventral penetration would
pass through only a single nervous layer, hence
yielding positive information concerning the na-
ture of the response of that tissue. Additional
substantiation for electrode location was often
found in the fact that nervous responses would
remain essentially identical throughout a wide
range of electrode penetration, and then sud-
denly change with a very small shift in electrode
position. Dissections confirmed that these
changes in waveform corresponded with mea-
surements indicating the simultaneous passage of
the electrode into another tissue layer.
Results
Since the purpose of this investigation was to
follow the transmission of information from
photoreceptors to photc^erebrum, the most logi-
cal organization of results would seem to be
morphological, commencing with the eye itself
and progressing proximally towards the brain.
The Eye
Potentials recorded from the most distal por-
tions of the visual pathway (/.<?., from the sur-
face of the cornea, or subcorneally) have been
the subject of many investigations. The wave-
form and diurnal variation of the ERG of H.
erato has been previously published (Swihart,
1963, 1964). Unfortunately, many such studies
have utilized such long duration stimuli that the
fine structure of the ERG was not apparent.
The most significant small potential is usually
the earliest observable response to stimulation.
Previously (Swihart, 1963), the day-phase ERG
had been reported as possessing an A wave, par-
ticularly in response to long wavelength stimu-
lation, and the rising slope of the B wave as con-
taining slight irregularities. This is, indeed, an
oversimplification of the complex pattern of
interactions which produce the first portion of
the ERG. The very earliest observable response
1965]
Swihart: Evoked Potentials in the Visual Pathway of Heliconius erato
57
is usually a small, brief, negative potential, with
a latency of about 8 msec. If both this potential
and an A wave are present, then the negative
potential will always precede. Characterized by
a short latency and a phasic nature, this potential
seems to be little affected by stimulus duration.
Fig. 1 illustrates this initial response in ERGs
produced by white light stimulation.
At times it is difficult to observe this potential
closely. This is due, in large measure, to its being
submerged in background noise of nervous ori-
gin. The most convenient technique for remov-
ing this interference was found to be the sup-
pression of spike potentials by administering a
drop of 10% procaine to the preparation. While
this markedly affected the ERG waveform, by
eliminating the efferent components, the shape
of the initial potential did not appear to be modi-
fied, and higher amplifications were possible.
Figs. 1 & 2 illustrate this potential in anesthe-
tized preparations. Its variation as a function of
stimulus wavelength is demonstrated in Fig. 2.
It will be noted that a positive A wave is pres-
ent in the responses to the longer wavelengths.
At shorter wavelengths, the magnitude of this
negative potential increases and the latency of
subsequent portions of the ERG decreases, thus
concealing any positive A wave that might have
occurred with a latency comparable to that ob-
served at longer wavelengths. It should be noted
that these brief, initial negative responses can
normally be recorded only from the vicinity of
the cornea. Electrodes placed very much deeper
than the distal pigment concentration usually
fail to record this phenomenon.
Directly beneath this area large negative re-
sponses develop. These appear to be graded ac-
tion potentials, which develop when the initial
response reaches a critical magnitude (Figs. 1
& 3), hence the latency is proportional to stimu-
lus intensity. It is likely that these potentials
constitute the largest portion of the leading edge
of the ERG B wave (Fig. 4).
When a capillary electrode is placed near the
center of the retinula cells (i.e., between the pig-
ment concentrations), simple monophasic nega-
tive potentials are recorded. These may be of
very large size (up to 10 mV), and seem to be
particularly responsive to stimulation with longer
wavelengths (Fig. 5.)
One might be tempted to consider this poten-
tial as functionally related to those recorded
more distally. This interpretation, however,
seems most unlikely since these responses have
distinctly different spectral sensitivities, with the
initial responses being blue-green sensitive, and
the deep negative potential being maximally sen-
sitive to red (616 m^.). Latency considerations
also tend to substantiate this viewpoint, for the
latency of this deep response is usually much
greater ( ca . 15 msec.) than the more distal re-
sponses. Recordings from an intermediate lo-
cation illustrate the independence of this effect
and the brief initial negative response (Fig. 6).
It appears, therefore, that both this deep, large
negative response and the initial phasic response
may be considered as receptor potentials, reflect-
ing the activity of two different categories of
receptors with different spectral sensitivities.
Still deeper electrode penetration results in
producing an entirely different type of response,
which is a comparatively short latency positive
potential (Fig. 7). Both the spectral sensitivity
and latency of this effect seem to be identical
to that of the deeper, large negative potential. It
is sometimes difficult to obtain good recordings
of this waveform in an intact preparation due to
its extreme localization. It is, however, much
simpler in the case of a procaine-anesthetized
animal, under which circumstances it invades
and dominates the responses recorded from
much of the nervous tissue in the visual pathway.
It should be noted that this potential is most
clearly recorded from the region of the proximal
pigment cells and in the tracheated tissue layer
and not in the lamina gangularis, as has been
previously suggested (Autrum, 1958).
On the basis of action spectrum and latency,
it is the author’s opinion that these positive po-
tentials represent a reflection of the deep nega-
tive response, induced by current flow resulting
from receptor depolarization, and spreading
electrotonically. It seems likelv that it is this po-
tential which is responsible for the positive ERG
A wave at long wavelengths.
The lamina gangularis
Much discussion has arisen concerning the
role of the lamina gangularis. Recordings from
this area typically present a waveform consisting
of a large, but brief, positive potential, followed
by a sustained negativity. It appears that this
waveform represents the summation of the pre-
viously discussed positive potential, and a graded
action potential of negative polarity (Fig. 8).
The apparent similarity in the sizes of the posi-
tive potential in this figure is somewhat mislead-
ing, since vastly different white light stimulus
intensities will also produce matching positive
deflections. It seems likely that this constancy in
size is due to the interaction of two components
of opposite sign which vary nearly proportion-
ately and hence maintain a nearly constant re-
lationship. The negative potential recorded at
this level clearly has a different spectral sensitiv-
ity than the ERG, being maximally sensitive to
long wavelengths.
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Medulla externa
Responses recorded from this region appear
to be largely of spike potential origin. Swihart
(1964) described the patterns of single fiber re-
sponses observed in this general region of the
visual pathway. No additional types of fibers
have been observed. During the course of these
experiments, slightly larger electrode tip diam-
eters and the use of electrical filters served to
assist in the recordings of summated potentials
from small areas of the neuropile. Such record-
ings illustrate that there is a morphological lo-
calization of specific fiber types.
Swihart (1964) emphasized the role of effer-
ent components in the ERG. Most significant of
these effects were: ( 1 ) a B wave nervous compo-
nent, excitatory in function, resulting from the
summated response of “on” fibers, maximally
sensitive to the blue-green and probably origi-
nating in the medulla interna; (2) a positive
“dip” following the B wave, which served to in-
hibit receptor depolarization, resulting from the
inhibition of spontaneously active, red-sensitive,
neurons, located in the medulla externa; and (3)
an “off” effect (D wave), arising in the medulla
interna from the activity of red-sensitive fibers.
Recent investigations have supported the pre-
vious observations, with one exception: the ori-
gin of the B wave nervous component. Nearly
pure “on” responses were most clearly recorded
from the proximal periphery of the medulla ex-
terna (i.e., the vicinity of the cortex), particularly
in those regions not closely covered by the lam-
ina gangularis (Fig. 9).
Recordings from the interior of the externa
produce a sustained positive response which ap-
pears to be a summated response reflecting the
inhibition of spontaneously active neurons (Fig.
10). Latency considerations clearly differentiate
between the positive potentials which arise in the
receptors (latency ca. 15 msec.) and those ob-
served in the medulla externa (latency ca. 25
msec.) .
It is interesting to note that the B wave ner-
vous component responds to an increase in stim-
ulus intensity by a decrease in magnitude, while
the size of the positive response is directly pro-
portional to stimulus intensity (Fig. 11). This
is precisely what would be expected if the B wave
component were excitatory, and the positive po-
tential inhibitory, with their interaction tending
to stabilize the degree of receptor depolarization.
Such complex responses to stimulus intensity
make it difficult to meaningfully evaluate the
spectral response of these effects. It should, how-
ever, be noted that the positive response is often
preceded by a brief positive potential which can
easily be distinguished from the response itself
(Fig. 12). It seems likely, therefore, that the
level of spontaneous activity is regulated by the
electrotonic potentials which originate in the re-
ceptors.
Morphologically, the medulla externa resem-
bles a cup-shaped structure, with the opening
towards the posterior. Thus, only the distal half
of the “cup” is located directly beneath the re-
ceptors. Jn the anterior and proximal portions
of the structure, the magnitude of the positive
response is considerably reduced. In this region
a negative potential, similar to that recorded in
the lamina gangularis, becomes dominant (Fig.
13) . This description may also be applied to
potentials recorded from the internal chiasma.
Medulla interna
The medulla interna is structurally the small-
est of the tissues of the visual pathway, being
located in the “cup” formed by the medulla ex-
terna. Recordings from the posterior surface of
this structure reveal a pure “off” response (Fig.
14) .
The interior, however, produces a large nega-
tive response (Fig. 15) with an extremely long
latency {ca. 30 msec.), and great sensitivity to
long wavelengths (Text-fig. 1). It would seem
that this response represents the activity of fibers
characterized previously (Swihart, 1964) as
showing maximal activity during the C wave.
Such long latencies suggest that such a re-
sponse would be incapable of following a rapidly
flickering stimulus. This is indeed the case; flicker
fusion frequencies (F.F.F.) of the various re-
sponses vary greatly, being related to the latency
of the particular effect. Thus the F.F.F. of the
large negative receptor response, recorded from
the center of the eye, is markedly lower than that
of the ERG (Fig. 16). The frequency reaches
a low of less than 40 c.p.s. in certain portions of
the brain.
Protocerebrum
Two distinctly different types of response ap-
pear to dominate the main (dorsal) mass of the
protocerebrum. The posterior portion demon-
strates a brief, long latency, positive potential
(Fig. 17). which could possibly represent an
inhibition of the spontaneous activity known to
exist in the mushroom bodies. This response is
usually of low magnitude, and difficult to ana-
lyze, but appears to be proportional in size to
the magnitude of the ERG B wave {i.e., blue-
green sensitive).
The anterior, dorsal portion of the protocere-
brum shows a negative response which closely
resembles that observed in the medulla interna
(Fig. 18). In fact, it seems more than likely it
is this effect which induces this brain response.
1965]
Swihart: Evoked Potentials in the Visual Pathway of Heliconius erato
59
Text-fig. 1. Luminosity curves obtained by ploting the responses recorded from the medulla interna (long
latency, negative response, see Fig. 15). The solid line with triangles indicates the magnitude of the responses
elicited by stimulation with constant energy ( ca . 300 microwatts). The plot formed by dashed lines and
circles represents the magnitude of the same response, as measured in another individual, when stimuli
intensities were adjusted so as to produce equal magnitude ERG B waves. It will be observed that in each
case the maximum response is reached at the same wavelength (616 m^n). Note also the manner in which
the response is maintained at a constant magnitude, at longer wavelengths, when the ERG magnitude is
maintained at a constant size. This would seem to indicate that the receptor responsible for producing the
medulla interna response is also responsible for the ERG B wave at wavelengths greater than 616 m/x.
Fig. 19 illustrates the result of single fiber record-
ings from this region. It will be noted that spike
potentials are associated with a sustained nega-
tive potential (somewhat suppressed in these
recordings due to the use of a high frequency
bandpass filter). Since both the magnitude and
duration of this potential is greater in response
to stimulation with long wavelengths (for a
given magnitude of ERG), a greater response in
terms of spike potentials is induced by such stim-
uli. While short wavelength, high intensity stim-
uli may produce a high instantaneous spike
frequency, the longer wavelengths will produce
a train of spikes with a duration at least 25%
longer (comparison of 528 and 616 m^). Low
intensity, short wavelength stimuli may com-
pletely fail to elicit spike potentials, while longer
wavelengths produce well defined trains.
Electrodes which penetrate the ventral por-
tions of the protocerebrum record a large variety
of response types. Many of these are of a com-
plex waveform, with latencies much shorter than
the previously described “brain” responses (Fig.
20) . The physical distribution of these potentials
is, however, so narrow that they are extremely
difficult to work with experimentally.
Conclusions
These experiments have, in general, confirmed
previous observations concerning the origin and
nature of those potentials which comprise the
ERG. Fig. 21 illustrates the close match in slope
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Zoologica: New York Zoological Society
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and time between various nervous effects and
portions of the ERG.
It has become clear that the conventional
terminology for the ERG waveform is com-
pletely inadequate. Its adoption seems to have
arisen from the convenience of drawing a paral-
lel between the vertebrate ERG and the similarly
shaped (but of inverted polarity) insect ERG.
This has led to the unfortunate situation whereby
the terminology bears little relationship to bio-
logical reality. Thus, for example, the term “B
wave,” rather than designating a single homo-
genous potential, may well include as many as
four distinctly different components (i.e., two
receptor potentials, a graded action potential and
one of nervous origin).
The following terminology is, therefore, pro-
posed as retaining the advantages of the present
system, plus containing the precision necessary
for accurate description of insect ERG wave-
forms.
a (alpha) ; the initial phasic negative potential
of receptor origin.
A; retains its identification with the initial pos-
itive deflection which originates deep in the
receptors.
B; is maintained as a generic term referring to
the complex, large, negative “on” effect,
which may contain several components:
B'; a graded action potential,
B"; a large, receptor potential, and
B”; which is due to the activity of “on” fibers
in higher nervous centers.
C; continues as a generic term referring to the
response which is maintained throughout
the duration of stimulation. The C wave is
composed of two components of opposing
polarity:
C'; which is of negative polarity, and consists
largely of potentials of receptor origin,
C"; is of positive polarity, and is of nervous
origin.
D; continues to refer to the ERG “off” effect
which also appears to have the possibility
of containing two different components.
D'; which is the potential which dominates the
wave, and is due to the activity of “off”
fibers,
D"; which arises as an overshoot in the recov-
ery of the spontaneously active neurons. It
is possible that there are other effects which
contribute to the ERG “off” response.
These experiments have been purposefully
confined to the day-phase ERG, since its com-
plexity and behavioral associations were most
intriguing. Preliminary observations on the night
phase response indicate the presence of at least
some of the same types of nervous activity, par-
ticularly the spontaneous activity of the medulla
externa, albeit at a very much reduced level.
Elucidation of the exact source of the negative
potential which dominates the night-phase ERG
awaits further experimentation.
It will also require much additional effort be-
fore it becomes possible to state with certainty
the complete chain of events which are responsi-
ble for the passage of information from the eye
to the brain. In many cases complex waveforms
were recorded ( e.g ., Fig. 11) which were ana-
lyzed as being a summation of several simpler
patterns of response. This assumption may not
be entirely true, and other types of activity, not
described, may be significant.
In spite of such unanswered problems, certain
general conclusions are possible. It is increas-
ingly certain that in the case of H. erato, there
are two distinct types of receptors, with differing
spectral sensitivities, latencies, types of “output”
etc. Despite considerable interaction between the
receptors, their outputs remain sufficiently inde-
pendent to permit their association with particu-
lar patterns of nervous activity arising at dis-
crete locations along the visual pathway.
Those effects which arise in the medulla ex-
terna (i.e., B”', C") appear to serve primarily
in the regulation of receptor activity, rather than
the transmission of information. Although some-
what unlikely, it is possible that the inhibition of
spontaneous activity in the -externa may also
serve to transmit information to the interna, in
a manner analogous to that observed in the insect
ocellus (Ruck, 1961).
In any case, either directly or indirectly, the
red-sensitive receptor appears to be primarily
responsible for inducing the large, long latency
response found in the medulla interna.This effect
is doubtless a key step in the transmission of in-
formation to certain centers in the brain. It thus
serves to induce an activity pattern in neurons
in these higher centers which continues to ex-
hibit a disproportionate sensitivity to the color
red.
It seems clear, therefore, that the behavioral
sensitivity of H. erato to long wavelengths can
be given a firm basis in the physiology of the eye,
and the existence of specific neuronal pathways
that serve to mediate the transmission of sign
stimuli.
It is equally clear, however, that the analysis
of the sensory input from composite potentials,
such as the ERG, is totally unsatisfactory. As an
example, Magnus (1956) reported a behavioral
F.F.F. of about 75 c.p.s. for the fritillary Argyn -
nis paphia, while the ERG demonstrated a F.F.F.
1965]
Swihart: Evoked Potentials in the Visual Pathway of Heliconius erato
61
of 151 c.p.s. While this may be partially ex-
plained by differences in stimulus intensity
(Ferry-Porter law), it seems certain that it is
largely due to the limited capability of the ner-
vous system to transmit high F.F.F. Thus H.
er/ito shows a maximum F.F.F. subcorneally of
of about 160 c.p.s., and a F.F.F. at the medulla
interna of about 75 c.p.s.
It is firmly believed that continued electro-
physiological investigations into the responses
characteristic of the insect higher nervous cen-
ters will provide further information concerning
the physiological basis of innate behavior pat-
terns.
References
Autrum, H.
1958. Electrophysiological analysis of the visual
system in insects. Exp. Cell Res., Suppl., 5:
426-439.
Autrum, H., & H. Stumpf
1953. Electrophysiologische Untersuchungen
uber das Farbensehen von Calliphora.
Zeit. vergl. Physiol., 35: 71-104.
Burtt, E. T„ & W. T. Catton
1956. Electrical responses to visual stimulation
in the optic lobes of the locust and certain
other insects. J. Physiol., 133: 68-88.
Crane, J.
1955. Imaginal behavior of a Trinidad butterfly,
Heliconius erato hydara Hewitson, with
special reference to the social use of color.
Zoologica, 40: 167-196.
Ford, E. B.
1945. Butterflies. Collins, London, xiv + 368 pp.
Goldsmith, T. H.
1960. The nature of the retinal action potential
and the spectral sensitivities of ultra-violet
and green receptor systems of the com-
pound eye of the worker honeybee. J. Gen.
Physiol., 43: 755-799.
Kaye, W. J.
1921. A Catalogue of the Trinidad Lepidoptera,
Rhopalocera (Butterflies). Mem. Dept, of
Agriculture, Trinidad and Tobago, No. 2,
xii -f 163 pp.
Magnus, D. B.
1956. Experimental analysis of some “overopti-
mal” sign-stimuli in the mating-behavior
of the fritillary butterfly Argynnis paphia
L. (Lepidoptera: Nymphalidae). Proc.
Tenth Inter. Cong, of Ent., 2: 405-418.
Ruck, P.
1961. Electrophysiology of the insect dorsal
ocellus. J. Gen. Physiol., 44: 605-657.
Schneider, D.
1962. Electrophysiological investigation of the
olfactory specificity of sexual attracting
substances in different species of moths.
J. Ins. Physiol., 8: 15-30.
Swihart, S. L.
1963. The electroretinogram of Heliconius erato
(Lepidoptera) and its possible relation-
ship to established behavior patterns. Zoo-
logica, 48: 155-165.
1964. The nature of the electroretinogram of a
tropical butterfly. J. Ins. Physiol., 10: 547-
562.
62
Zoologica: New York Zoological Society
[50: 5: 1965]
Fig. 1
Fig. 2
Fig. 3
Fig.
EXPLANATION OF THE PLATE
PLATE I
ERG recorded with steel, subcorneal elec-
trode. Procaine anesthesia. Responses to
white light stimulation (ca. 62,000 micro-
watts) of various durations (10, 20 and
40 msec.) superimposed. Upward deflec-
tion of lower trace indicates period of stim-
ulation.
produce equal magnitude ERG B waves
(upper trace). Note that in this and all
subsequent ERG recordings, red produces
the greatest “dip” following the ERG B
wave, and the largest “off” response. Stim-
ulus duration 100 msec. Note also that the
receptor responses (center trace) match
each other, and that the size, slope and
timing of the leading edge of the receptor
response are identical to the leading edge
of the ERG B wave.
Comparison of ERGs and response from
the center of the retinula cells (between
pigment cells). Details of stimuli as in Fig.
4. Note that the response to the longer
wavelength is more than twice as great as
that elicited by the blue-green, even though
similar-sized ERGs are produced. It will
also be noted that the size, slope and la-
tency of this response are markedly differ-
ent from that of the ERG B wave.
6. Stimulation and recording as in Fig. 5. ex-
cept that in this case the capillary electrode
picked up part of the initial, superficial
response also. This is more clearly shown
in the photographic enlargement of the
leading edge of the recording of receptor
activity (part B). Note that the initial re-
sponses match in size and shape when the
ERGs match (c./., Fig. 2 where constant
energy stimuli was employed ) . The latency
and magnitude of the deeper response are,
however, totally independent of the size of
the initial response.
Initial portions of ERG response to vari-
ous colors, procaine anesthesia, steel elec-
trode. Sweep was triggered 1.5 msec, after
onset of stimulation. Stimulus energy about
300 microwatts at each wavelength.
Simultaneous recording from cornea (top
trace) and vicinity of distal pigment cells
(latter with capillary electrode), demon-
strating the variation in response charac-
teristic of various stimulus intensities;
procaine anesthesia. Eight responses are
superimposed, each representing a white
light stimulus with twice the energy con-
tained in the preceding. Maximum stimu-
lus ca. 62,000 microwatts. Time base as in
Fig. 2. Stimulus duration, 20 msec, (bot-
tom trace), with delayed sweep trigger.
Note that the initial superficial response
has a relatively constant latency (about 12
msec, in this specimen), unlike the deeper
response.
Recordings from the same sites as in Fig. 3,
except without anesthesia. Demonstrates
the superimposed responses to two differ-
ent colors (blue-green, 528 m/j, and red,
616 m/x) with intensities adjusted so as to
SWIHART
PLATE I
EVOKED POTENTIALS IN THE VISUAL PATHWAY OF HELICONIUS ERATO ( LEPI DOPTERA )
EXPLANATION OF THE PLATE
PLATE II
Fig. 7. Responses recorded from the vicinity of the
tracheated tissue layer. Stimulus details as
in Figs. 5 and 6 (100 msec, duration,
matching 528 m /jl and 616 m^). Long
wavelengths produce the greatest positive
deflection. Note that the size, slope and la-
tency of this positive response are quite
different from the “dip” following the ERG
B wave.
Fig. 8. Responses recorded from the lamina gang-
ularis. Stimuli characteristics similar to
Fig. 7. Note the red produces the greatest
negative response.
Fig. 9. Response characteristic of the cortex of
the medulla externa. Stimuli characteris-
tics as in Fig. 7.
Fig. 10. Response recorded from the center of the
medulla externa. Stimuli characteristics as
in Fig. 7. Note that the long wavelength
produces the greatest positive deflection,
and that the size, slope and latency of this
effect are very similar to that of the “dip”
following the ERG B wave (c./. Fig. 7).
Fig. 11. Parts A-D show variation in response of
medulla externa (recorded near internal
chiasma) to variations in stimulus inten-
sity. Stimulus energy increased four-fold
in each successive recording. Note the
decrease in the magnitude of the nervous
response which accompanies an increase
in stimulus intensity. Part E, superimposed
recordings from a freshly emerged adult
which has not yet developed a normal
ERG. White light stimuli with relative
energies of 1:16:132. Center trace illus-
trates responses recorded from the ex-
terna (close to the internal chiasma).
Strongest stimulus produced smallest neg-
ative “on” response and a sustained posi-
tive response during stimulation. Weakest
stimulus produced the largest “on” re-
sponse. Stimulus duration 100 msec.
SWIHART
PLATE 11
EVOKED POTENTIALS IN THE VISUAL PATHWAY OF HEL1CONIUS ERATO (LEPIDOPTERA)
EXPLANATION OF THE PLATE
Plate III
Fig. 12. Response from the center of the medulla
externa, white light stimulation (ca. 4,000
microwatts), 100 msec, duration. Note the
two distinctly different positive compo-
nents which contribute to the nervous
response (c./. Figs. 7 & 10).
Fig. 13. Recordings from the medulla externa, near
the internal chiasma. Stimuli characteris-
tics as in Fig. 7 (100 msec, duration, 528
mp and 616 m p with intensities adjusted
for equal magnitude ERG B waves). The
long wavelength stimulus produced the
greatest negative deflection.
Fig. 14. Recording from the posterior surface of
the medulla interna, showing pure “off”
responses characteristic of that area. White
light stimulation (ca. 4,000 microwatts)
for 100 msec.
Fig. 15. Recordings from the center of the medulla
interna. Stimuli characteristics as in Fig.
13. Note that long wavelengths continue
to produce the greatest negative deflection.
Fig. 16. Recordings of responses to flickering stim-
ulation, white light (ca. 4,000 microwatts).
Upward deflection of bottom trace indi-
cates period of stimulation. Top traces are
ERGs. First recording is response of eye
(red-sensitive receptors) to 200 msec, of
flicker at the rate of about 70 c.p.s. Second
recording is from the portion of the proto-
cerebrum yielding positive responses (see
Fig. 17). Stimulus was 500 msec, of flicker
at about 40 c.p.s. Some distortion in the
waveform in these illustrations has re-
sulted from the use of 1 c.p.s. electrical
filter.
Fig. 17. Recording from the posterior, dorsal por-
tion of protocerebrum. Stimuli details as in
Fig. 13 (i.e., match of blue-green and red
stimuli).
Fig. 18. Superimposed recordings from the ante-
rior dorsal portion of the protocerebrum,
again matching the responses to 528 and
616 mp. The longer wavelength produces
the greatest negative deflection. Stimulus
duration 100 msec.
Fig. 19. Typical single fiber responses from the
same region that produced Fig. 18. In these
recordings, the top trace is the usual super-
imposed recordings of the ERG responses
to 528 and 616 mp, 100 msec. The second
trace is the single fiber responses to the
longer wavelength. This beam was then
moved to a lower position on the face of
the oscilloscope and the response to the
short wavelength stimulus was recorded
(third trace). Note the considerably longer
duration of “spike” activity elicited by the
long wavelength stimulus.
Fig. 20. One of the more complex response pat-
terns which are characteristic of regions
deep within the protocerebrum. White light
stimulation ( ca . 4,000 microwatts), 100
msec.
Fig. 21. Several recordings of “nervous” responses
which tend to illustrate the manner in
which such effects contribute to the ERG
waveform.
First recording: a highly aberrant ERG
which is almost totally without a B wave,
and a simultaneously recorded “on” re-
sponse from the medulla externa. Note
that even in this extreme case, it is the time
of cessation of the nervous “on” effect
which determines the time of the “dip”
following the B wave.
Second recording: This demonstrates the
close relationship between the positive re-
sponse produced by the medulla externa,
and the positive portion of the ERG wave-
form.
Third recording: This illustrates the man-
ner in which the response recorded deep
within the receptor layer contributes a neg-
ative component to the slope of the sus-
tained response.
SWIHART
PLATE III
EVOKED POTENTIALS IN THE VISUAL PATHWAY OF HELICONIUS ERATO ( LEPI DOPTERA )
6
Neurosine, Its Identification with N-acetyl-L-histidine
and Distribution in Aquatic Vertebrates1
Morris H. Baslow
Department of Marine Biochemistry and Ecology, New York Aquarium, New York Zoological Society
Introduction
Neurosine, a ninhydrin negative imidazole
fraction isolated from the brain of several
bony fish, amphibians and reptiles (Bas-
low, 1963; 1964) has been found to be similar to
an imidazole fraction (IMi) isolated by Correale
(1958) from the brain of several cold-blooded
vertebrates. Recent studies show that the major
imidazole compound in the IMi fraction of the
frog Rana esculenta is N-acetyl-L-histidine
(Anastasi et al., 1964). The identification of
neurosine, obtained from fish brain, with N-
acetyl-L-histidine and the phylogenetic and tis-
sue distribution of this compound in primitive
and modern fishes and other aquatic vertebrates
is reported.
Materials and Methods
Tissues were homogenized in a solution of
95% ethanol and 0.1 N HC1 (1:1) and ex-
tracted at 6°C for two hours as described pre-
viously (Baslow, 1964) . After centrifugation the
clear supernatant was used for analysis.
Paper chromatograms were run with n-bu-
tanol: acetic acid: water (4 : 1 : 5); n-butanol:
1.5 M-ammonia (75 : 25), and n-butanol : ace-
tone : water : ammonia (10 : 10 : 5 : 2) mix-
tures on Whatman #1 paper. The spots of the
neurosine imidazole fraction and authentic N-
acetyl-L-histidine (Calbiochem) were located
on paper chromatograms by the Pauly reaction.
Electrophoresis experiments were run at 400-
500 VDC (Beckman Duostat, cell model R,
series D) in 1% acetic acid; 1% NH+OH, and
M
.-sodium borate 10 H2O.
Hydrolysis of authentic N-acetyl-L-histidine
was carried out in 6N HC1 at 100°C for one
hour, and enzymatically with fish brain homo-
genates at 24°C for 1.5 hours.
’Supported by a grant from the John A. Hartford
Foundation Inc.
The content of N-acetyl-L-histidine in tissue
samples was determined by comparison of the
weight of the excised spot, after chromatography,
of a known amount of authentic substance with
that from a known amount of tissue extract
(Lederer & Lederer, 1957). Assay values were
found to be reproducible with a variation of
± 15%.
Observations and Results
A. Identification of neurosine with N-acetyl-
L-histidine. Previously, the ninhydrin negative
characteristic of the major imidazole present in
the neurosine fraction was ascertained, in addi-
tion to its ease of conversion into a ninhydrin
positive substance by hydrolysis in 6N HC1 at
100°C for less than one hour or by incubation
with fish brain homogenates (Baslow, 1964). In
this investigation, synthetic N-acetylhistidine was
found to have similar acid and tissue hydrolysis
characteristics with histidine recovered as a
product.
On descending paper chromatograms, both
the Pauly positive spot of neurosine and N-ace-
tylhistidine and similar Rf values of 0.31; 0.07
and 0.41 respectively in n-butanol : acetic acid
: water; n-butanol : ammonia and n-butanol :
acetone : water : ammonia and appear as a
single spot in analysis of mixtures.
On electrophoresis, neurosine and N-acetyl-
histidine behaved identically. At 500 VDC for
two hours in 1% acetic acid (pH 2.8), both
migrate 7.9 cm. toward the cathode; at 400 VDC
for two hours in ^ sodium borate (pH 8.8),
5.2 cm. toward the anode; and 500 VDC for one
hour in 1% NHtOH (pH 10.5), 0.9 cm. toward
the anode.
B. N-acetylhistidine in brain and other tissues
of primitive and modern fishes. In previous anal-
ysis of fish brains for the presence of neurosine
(N-acetyl-L-histidine), this substance could not
be found in the brain of the sea lamprey, Petro-
63
64
Zoologica: New York Zoological Society
50: 6
myzon marinus, and the spiny dogfish, Squalus
acanthias, although it was present in all bony
fish examined (Baslow, 1964). A survey of the
brains of various fishes for the presence of this
compound (Table I) and its distribution within
the nervous system and other tissues of the killi-
fish, Fundulus heteroclitus (Table II) are re-
ported.
C. N -acetylhistidine content in the brain of
other poikilothermic vertebrates and fish-eating
mammals. Analysis of the brain of various cold-
blooded vertebrates and the rat, mouse and chick
have shown that the neurosine or IMi fraction
was present in amphibians and reptiles in addi-
tion to fish, but absent from the brain of homeo-
thermic animals (Correale, 1958, 1964; Baslow,
1964). In Table III the results of analysis of
brains and other tissues of several poikilotherms
and some fish-eating mammals are presented.
Table I. N-acetylhistidine in the Brain of Modern and Primitive Fish Species
Thermal
N-acetylhistidine
Class
Species
Range1
Salinity2
(jUg/gram Fresh Tissue)
OSTEICHTHYES
Opsanus tau (toadfish)
T
M
820
Spheroides maculatus (puffer)
T
M
975
Opisthognathus aurifrons (jawfish)
W
M
1,920
Pomatomus saltatrix (bluefish)
T
M
1,350
Fundulus heteroclitus (killifish)
T
M
1,080
Hippocampus hudsonius (seahorse)
W
M
1,870
Brevoortia brevicaudata (menhaden)
T
M
1,970
Chaetodon ocellatus (butterfly)
W
M
1,830
Lobotes surinamenisis (tripletail)
W
M
1,760
Prionotus evolans (sea robin)
T
M
1,470
Osteoglossum bicirrhosum (arowana)
W
FW
610
Electrophorus electricus (electric eel)
W
FW
1,000
Malapterurus electricus (electric catfish)
w
FW
1,520
Gymnarchus niloticus (knife-fish)
w
FW
380
Amia calva (bowfin)
T
FW
200
Polypterus ornatipinnis (bichir)
w
FW
430
Calamoichthys calabaricus (reedfish)
w
FW
500
Chondrichthyes
Mustelus canis (smooth dogfish)
T
M
Sphyrna tiburo (bonnetnose shark)
w
M
Carcharias limbatus (blacktip shark)
w
M
Negaprion brevirostris (lemon shark)
w
M
Dasyatis americana (southern stingray)
> w
M
«20
Urolophus jamaicensis (yellow stingray)
w
M
Hydrolagus colleii (ratfish)
Ar
M
Agnatha
Myxine glutinosa ( hagfish) _
Ar
M
Lower limit of the method 20 pg/ gram of tissue
’Temperate (T), Warm (W), Arctic (Ar).
-Marine (M). Fresh Water (FW).
1965]
Baslow: Neurosine, Its Identification and Distribution
65
Table II. N-acetylhistidine in the Nervous System and Other Tissues
of the Killifish Fundulus heteroclitus
N-acetylhistidine
Tissue
(/xg/gram Fresh Tissue)
Brain
Telencephalon
950
Diencephalon
760
Mesencephalon
1,000
Metencephalon
1,000
Myelencephalon
500
Spinal cord
240
Eye
Lens
765
Retina (pigment, chorioid and all cell layers)
165
Ocular fluid (vitreous and aqueous humors)
« 10/ml
Optic nerve
90
Heart
Liver
>
«20
Muscle
Lower limit of the method
20 jUg/gram of tissue
Table III. N-acetylhistidine Content of the Brain
POIKILOTHERMS AND FlSH-EATING MAMMALS.
of Several
Species
N-acetylhistidine
(/xg/gram Fresh Tissue)
Amphibians
Triturus viridescens (salamander) 715
Rana pipiens (grass frog) 580
Reptiles
Pseudemys floridana (turtle) 410
Mammals1
Phoca groenlandicus (harp seal)
Phoca hispida (ringed seal)
Phoca vitulina (harbor seal)
Delphinapterus leucas (white whale)
Eye >
Lens
Retina (pigment, chorioid and all
cell layers)
Ocular Fluid (vitreous humor)
Lower limit of the method
«20
20 jug/gram of tissue
'Tissues obtained 1-4 hours post-mortem.
66
Zoologica: New York Zoological Society
50: 6
Discussion
The distribution of N-acetyl-L- histidine in the
brain of fish seems to be based upon phylogen-
etic relationships rather than on the basis of
environmental factors such as salinity and tem-
perature. The substance could not be found in
the brain or other tissues of several fish-eating
mammals even though their daily intake may
reach 200 milligrams. Quantitatively, there ap-
pear to be lower concentrations of this com-
pound in the brain of fresh water bony fish and
amphibians than in marine forms. N-acetylhisti-
dine could not be found in the brain of members
of the primitive fish classes, the Agnatha and
Chondrichthyes, although Correale (1958) has
reported relatively large amounts of the IMi
fraction in the shark, Mustelus mustelus.
Four imidazole fractions have been isolated
from the brains of elasmobranchs, one of which
(CQ runs faster (Rf0.40) than N-acetylhisti-
dine and another (C3) which runs behind
(Rf0.26) this compound in an n-butanol: ace-
tic acid: water system (Baslow, unpublished ob-
servation). The individuality of the C4 and Ca
components has been established by the addition
of authentic N-acetylhistidine to elasmobranch
brain extracts prior to chromatography. The C2
fraction (R{0.22), which is present in fairly
high concentration, has only been isolated from
members of the Chondrichthyes and may rep-
resent the major imidazole in the IMi fraction
isolated from this group.
The presence of N-acetylhistidine in the optic
nerve, retina and lens of fish may indicate an
important role in visual processes. The meaning
of these findings and those of Correale (1958),
who found appreciable concentrations of N-ace-
tylhistidine in frog retina, and of Anastasi et al.
(1964) who find large quantities of this sub-
stance in amphibian lens is, however, obscure.
Ninhydrin-negative or faintly ninhydrin-positive
substances also reported in the N-acetylhistidine
fraction are probably the source of amino acid
residues isolated upon acid hydrolysis of the
neurosine fraction (Baslow, 1964). It is sug-
gested that the presence of this substance is
associated with development of higher order
central nervous control and integration of senses
typical of bony fish and their descendants, the
tetrapoda.
Summary
Neurosine, a ninhydrin-negative imidazole
fraction, isolated from the brain of cold-blooded
vertebrates, has been identified with N-acetyl-L-
histidine. This compound has been found in the
brain of bony fish (Osteichthyes) but could not
be identified in the brain of more primitive fish,
the cyclostomes (Agnatha) and sharks, rays and
chimeras (Chondrichthyes).
N-acetylhistidine has been found in high con-
centration in the lens, optic lobes (mesence-
phalon) and cerebellum (metencephalon) and
in lower concentration in the retina and other
portions of the brain and spinal cord, but not in
other bony fish tissues. It has been found in the
brain of bony fish living under all conditions of
physical activity, inhabiting environments in-
cluding marine and fresh waters and living in
thermal environments including tropical and
temperate waters.
***Since this article went to Press, Erspamer
et al. (Journ. Neurochem., Vol. 12, Pt. 2, pp. 123-
130, 1965) have suggested that neurosine and N-
acetyl-L-histidine are identical, and have confirmed
the absence of this compound in elasmobranchs.
Acknowledgments
I am indebted to M. F. Stempien of the De-
partment of Marine Biochemistry and Ecology,
New York Zoological Society, and H. W.
Graham of the Bureau of Commercial Fisheries,
Woods Hole, for the procurement of brains of
sharks and rays; to L. Margolis and J. A.
Thomson of the Fisheries Research Board of
Canada, Nanaimo, for chimera brains; and to
P. Montreuil and C. Ray of the New York
Aquarium for hagfish, seal and whale brains.
Literature Cited
Anastasi, A., P. Correale & V. Erspamer
1964. Occurrence of N-acetylhistidine in the
central nervous system and the eye of
Rana esculenta. J. Neurochem., 1 1 : 63-66.
Baslow, M. H.
1963. The enzymatic degradation of neurosine as
an index of fish quality. Am. Zoologist, 3
(4): 536.
1964. Neurosine, a new oligopeptide isolated
from the brain of fish and other cold-
blooded vertebrates. I. Identification and
partial characterization. J. Fish. Res. Bd.
Canada, 21 (1): 107-113.
Correale, P.
1958. Presenza di sostanze imidazoliche nel sis-
tema nervoso centrale dei vertebrati in-
feriori. Boll. Soc. ital. Biol, sper., 34 ( 12) :
601-604.
1964. Presenza di composti imidazolici negli es-
tratti di encefalo di anfibi Sud-Americani.
Boll. Soc. ital. Biol, sper., 40 (4) : 170-172.
Lederer, E„ & M. Lederf.r
1957. Chromatography, a review of principles
and applications. Elsevier Publishing Co.,
New York, 711 pp.
ZOOLOGICA
SCIENTIFIC CONTRIBUTIONS OF THE
NEW YORK ZOOLOGICAL SOCIETY
VOLUME 50 • ISSUE 2 • SUMMER, 1965
PUBLISHED BY THE SOCIETY
The ZOOLOGICAL PARK, New York
Contents
PAGE
7. A New Trematode, Cathaemasia senegalensis, from the Saddle-bill Stork,
Ephippiorhynchus senegalensis (Shaw). By Horace W. Stunkard &
Charles P. Gandal. Text-figure 1 67
8. A Device for Sonic Tracking of Large Fishes. By George A. Bass &
Mark Rascovich. Plates I & II; Text-figures 1-5. 75
9. Studies on Virus Diseases of Fishes. Spontaneous and Experimentally In-
duced Cellular Hypertrophy (Lymphocystis Disease) in Fishes of the New
York Aquarium, with a Report of New Cases and an Annotated Bibliog-
raphy (1874-1965). By Ross Nigrelli & George D. Ruggieri, S.J.
Plates I-X. 83
10. Vortices and Fish Schools. By C. M. Breder, Jr. Plates I-IV; Text-figures
1-3 97
Zoologica is published quarterly by the New York Zoological Society at the New York
Zoological Park, Bronx Park, Bronx, N. Y. 10460, and manuscripts, subscriptions, orders for back
issues and changes of address should be sent to that address. Subscription rates: $6.00 per year;
single numbers, $1.50, unless otherwise stated in the Society’s catalog of publications. Second-class
postage paid at Bronx, N. Y.
Published August 27, 1965
7
A New Trematode, Cathaemasia senegalensis, from the
Saddle-bill Stork, Ephippiorhynchus senegalensis (Shaw)1
Horace W. Stunkard2 & Charles P. Gandal2
(Text-figure 1)
A PAIR of saddle-bill storks, Ephippiorhyn-
chus senegalensis, known in Africa as
l. "Jabiru,” were received at the New York
Zoological Park, New York City, on July 3,
1964. The female died December 28, 1964, and
twenty-six worms were found in the throat and
esophagus. Identical worms have been removed
from the throat of the male bird also and since
in captivity there was no probability of infection
by trematodes, it appears that the parasites were
acquired in Africa. According to a statement
from the Import-Export-Zoo, Animals, Greven-
hofsweg 27, Harderwijk, Holland, the birds were
imported from Nigeria, and had been in Holland
about three weeks before shipment to America.
Whether or not they were taken in Nigeria is not
definitely established, but the species has a nor-
mal range throughout tropical Africa, from
Senegal to the Sudan and south to Southern
Rhodesia and Natal. It frequents and feeds in
swamps by the larger rivers and its food does
not differ from that of the white and black
storks. According to Bannerman (1953), it is
said to be partial to large water-beetles and has
been known to swallow a 3-lb. lung-fish. There
is no evidence that the saddle-bill is migratory
and it appears to be a resident bird. On the upper
Nile, it breeds in January and February.
Ten worms were studied as stained and cleared
whole-mounts and others in transverse and
frontal serial sections. The whole-mounts were
stained with paracarmine and the sections with
haematoxylin and erythrosin. The worms are
ovate in outline, with an anterior, mobile, pre-
acetabular conical portion and a wider, flattened.
1This investigation was supported by Grant NSF
G-23561.
-Research Associate, The American Museum of Nat-
ural History, New York, N. Y. 10024.
"Veterinarian, The New York Zoological Park, Bronx,
N._ Y. 10460.
oval posterior portion (Text-fig. 1). All are sex-
ually mature and their uteri are filled with eggs.
Different specimens vary in size from 9 mm. in
length and 5 mm. in width to 14 mm. in length
and 6.2 mm. in width. The cuticula measures
0.025 to 0.035 mm. in thickness and the ventral
preacetabular region bears broad, flat scales,
0.055 to 0.065 mm. in length, each of which is
composed of 2-6 fused spines. In certain speci-
mens, the scales, smaller and sparser posteriorly,
extend past the acetabular level. The acetabu-
lum, situated about three-eighths of the body
length from the anterior end, measures 1 .42 to
1.87 mm. in diameter.
The oral sucker is subterminal and varies from
1.00 to 1.87 mm. in diameter. The prepharynx
in a sectioned specimen is 0.31 mm. long and
0.22 mm. wide. The anterior end of the worm is
often bent ventrad and the pharynx may appear
in part dorsal to the oral sucker; in such prepa-
rations the prepharynx is not apparent. The
pharynx is 0.61 to 0.67 mm. long and 0.53 to
0.57 mm. wide. The esophagus has small lateral
evaginations, especially near the anterior end; it
extends to a level about midway between the oral
and ventral suckers. It is lined with epithelium
continuous with that of the digestive ceca, which
have small diverticula and end blindly near the
posterior end of the body.
The excretory pore is dorsal, near the poste-
rior end of the body, and the system, like that of
the echinostomes, is exceedingly branched, form-
ing a reticulum in the parenchyma and a lattice
of excretory tubules in the body wall.
The testes are situated, one before the other,
in the posterior third of the body. They are den-
dritic and the branches of the two organs over-
lap so much that it is difficult and usually im-
possible to distinguish one from the other. In
cross sections, there may be as many as six to
eight branches, one above the other. The lobes
67
68
Zoological New York Zoological Society
[50: 7
of the testes underlie but do not extend laterally
beyond the digestive ceca. The posterior testis
is flattened anteriorly where it meets the anterior
one and posteriorly it extends almost to the pos-
terior end of the body. The anterior testis has
a narrow bridge-like medial portion and two
lateral, wing-like portions that extend forward
to a level about midway between the acetabulum
and the posterior end of the body and far ante-
rior to the ovary. Sperm ducts pass forward on
either side between the digestive ceca and the
coils of the uterus. They tend mediad and dor-
sad, and dorsal to the anterior margin of the
acetabulum they join to form an S-shaped semi-
nal vesicle, enclosed in the cirrus-sac which is
circular to oval, 0.75 to 0.94 mm. in diameter.
The vesicle is in the dorsal part of the cirrus-sac;
it is followed by a much-coiled ejaculatory duct,
the initial portion of which is surrounded by se-
cretory cells. The cirrus-sac is situated immedi-
ately anterior to the acetabulum and may in part
overlie it; it is dorsal to and slightly right of the
metraterm, whose tip is inclosed in the wall of
the cirrus-sac.
The ovary is median, situated near the junc-
tion of the third and posterior fourths of the
body-length. It is spherical to oval, 0.32 to 0.48
mm. in diameter. The oviduct arises at the dorsal
posterior margin and turns posteriad and ven-
trad where it enters Mehlis’s gland and expands
to form the ootype. As it enters the gland,
Laurer’s canal is given off and the duct from the
vitelline receptacle is received. The vitellaria
consist of many small follicles in the extracecal
areas from the level of the acetabulum to the
posterior end of the body. Usually the follicles
are continuous at the posterior end. Vitelline
ducts from the anterior and posterior follicles
join at the anterior margins of the cephalic testis
and the resulting ducts pass posteriad and mediad
on the dorsal side of the body. They join behind
the ovary to form a large vitelline reservoir from
which a common duct passes anteriad and ven-
trad to open into the oviduct. Spermatozoa may
be present in the ootype and the initial portion of
the uterus, as it emerges from the ootype, is filled
with spermatozoa, but there is no seminal recep-
tacle. The first eggs are suspended in masses of
spermatozoa. The uterus coils posteriad until it
abuts against the median face of the anterior
testis and then forward in transverse loops, some-
times as many as six or eight above one another,
between the digestive ceca, to the level of the
acetabulum. The terminal portion of the uterus
passes on the left and below the cirrus-sac while
the metraterm enters the ventral wall of the cir-
rus-sac to open at the common genital pore. The
eggs are thin-shelled, operculate, and when ex-
pelled are 0.057 to 0.062 mm. in length, 0.032
Text-fig. 1. Cathaemasia senegalensis, type speci-
men, 11.5 mm. long, ventral view.
(Abbreviations)
A— Acetabulum
C— Cirrus-sac
I— Intestinal cecum
M— Mouth
O— Ovary
Ti— Anterior testis
To— Posterior testis
U— Uterus
V— Vitellaria
to 0.037 mm. in width, and fully embryonated.
The miracidia are ocellate and the eye-spots are
conspicuous. As noted by Dollfus (1950), the
eggs increase in size as they proceed along the
uterine coils.
Discussion
The genus Cathaemasia was erected by Looss
(1899) to contain a species described by Ru-
dolphi ( 1809) as Distoma hians from the esoph-
agus of the black stork, Ardea nigra (—Ciconia
nigra ) taken at Greifswald, Germany. Muhling
(1897) gave a more complete description and
figures of the species from parasites found in the
esophagus of the white stork, Ciconia ciconia. A
further account was given by Yoshida & Toyoda
( 1930) based on specimens from C. nigra which
had been imported from Africa and autopsied in
the Zoological Gardens of Osaka, Japan. The
1965]
Stunkard & Gandal: New Trematode from Saddle-bill Stork
69
species, hians, was included in the genus Dicro-
coelium by Dujardin (1845) when he erected
that genus, but morphological differences be-
tween Dicrocoelium dentriticum, type of the
genus, and MLihling’s redescription of D. hians
induced Looss (1899) to propose a new genus
for the latter species. The genus Cathaemasia
occupied an isolated taxonomic position until
Odhner ( 1926a) described the excretory system
of C. hians and predicated its close relationship
with the echinostomes, an opinion now generally
accepted.
L. Szidat (1939) reported the life-cycle of
C. hians. Twenty-three worms from the esoph-
agus of C. nigra lived for more than a week in
water (ca. 23° C.) and shed enormous numbers
of eggs. In sunlight, the miracidia emerged
promptly and were added to Petri-dishes con-
taining various species of snails. They entered
the snails and developed in Planorbis spp. and
Lymnaea palustris. Mother rediae appeared in
sporocysts after 10-12 days. Daughter rediae
migrated to the digestive gland and 37 days after
infection the first cercariae were shed. They
proved identical with Echinoc ere aria choano-
phila, larvae which Ursula Szidat (1936) had
found emerging from Planorbis spp. and Lym-
naea palustris and which encysted as metacer-
cariae in the choanae and roof of the mouth in
tadpoles of frogs and toads. The green frog,
Rana esculenta, is eaten regularly by the storks.
Until the discovery of the life-cycle of C.
hians, the species had uncertain taxonomic re-
lations. Looss (1899) included Cathaemasia
with Omphalometra Looss, 1899, in a new sub-
family, Omphalometrinae. Odhner (1911)
showed that Omphalometra was a member of the
Lepodermatidae (= Plagiorchiidae) and that
Cathaemasia manifested resemblances to the
fasciolids. Poche (1926) included Cathaemasia
in the family Fasciolidae. Fuhrmann (1928)
erected the family Cathaemasidae to contain
Cathaemasia and Mehlisia Johnston, 1913, a
genus based on Mehlisia acuminata Johnston,
1913, an intestinal parasite of the marsupial,
Dasyurus viverrinus, in Australia. Mehlisia was
included by Yamaguti (1958) in the family
Psilostomidae Odhner, 1913. The discovery of
the life cycle of C. hians threw new light on the
systematic position of Cathaemasia. The mor-
phology of the cercariae and the development of
circum-oral spines in the metacercarial stage
showed intimate relations with the echinostomes.
Moreover, Odhner (1926a) had shown that the
excretory system of Cathaemasia is similar to
that of the echinostomes. The adult stage, how-
ever, lacks the collar and spines and Szidat noted
morphological agreement between C. hians and
Philo phthalmus nyrocae. In species of these
genera, cuticular spines are largely restricted to
the ventral side of the body; the suckers are com-
parable in location, size and muscular develop-
ment; they agree in details of the digestive and
excretory systems, and in the location of the
testes, ovary, uterus and genital pore. In both,
the eggs are embryonated when passed and the
miracidia are ocellate. Members of these genera
live in the esophagus and on the ocular con-
junctiva, respectively, of birds, and Szidat predi-
cated that the Cathaemasidae and Philophthal-
midae are adventurous echinostomes that have
left the intestine and settled in new abodes. The
discovery of the life-cycle of Philophthalmus
gralli by Cable and his students, Fisher & West
(1958), however, showed that the philophthal-
mids have megalurous cercariae and that Cathae-
masia is nearer the echinostomes and psilosto-
mids than to the Philopthalmidae.
Several species have been assigned to Cathae-
masia; some of them have been removed to
other genera and the taxonomic status of others
remains equivocal. Braun (1901) described a
second species, Cathaemasia fodicans, from a
specimen in the Vienna Museum that, accord-
ing to the label, was from Sterna nigra, but later
authors, Odhner (1926b), Yoshida & Toyoda
(1930) and Szidat ( 1939) , regarded C. fodicans
as probably identical with C. hians. Odhner sug-
gested that the label on the specimen was an
error and should have been Ciconia nigra rather
than Sterna nigra. Odhner (1926b) described
two new species: Cathaemasia spectabilis from
the marabou stork, Leptoptilus crumenifer, tak-
en 25 years before during the Swedish Expedi-
tion to the White Nile, and Cathaemasia fame-
lica, based on a single specimen from the nim-
mersatt, Tantalus ibis, taken by the same Expe-
dition. It is a young individual, just beginning
egg-production, very similar to C. spectabilis,
and the differences may be explained by degree
of sexual maturity. Mendheim (1940) sup-
pressed C. spectabilis as identical with C. hians,
but the two species are probably distinct.
Wesley (1940) described three new species
of Cathaemasia from the esophagus of storks
taken in the region of Allahabad, U. P., India:
Cathaemasia orientalis from the white-necked
stork, Dissoura episcopus; Cathaemasia indicus
from the painted stork, Ibis leucocephalus; and
Cathaemasia mehrai from the Indian black ibis,
Pseudibus palillosus. The last species has a rudi-
mentary or vestigial circum-oral collar, with
twelve spines on each ventro-lateral corner. This
feature is a prime feature of the echinostomes,
and since the internal structure is so ' similar,
Wesley reduced Cathaemasidae to subfamily
status, Cathaemasinae, and included it in the
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Zoologica: New York Zoological Society
[50: 7
family Echinostomidae. The cercariae and meta-
cercariae of C. hians have circum-oral collars
and spines and otherwise are very similar to
those of Echinostoma revolution; moreover, the
adults of C. mehrai have collars and spines and
are so similar in internal morphology that the
decision by Wesley appears reasonable and jus-
tified. An additional species was described by
Wesley ( 1943) : Cathaemasia seetali from Xeno-
rhynchus asiaticus.
Von Linstow (1906) described specimens
from the esophagus of the white-necked stork,
Dissoura episcopus, taken in Ceylon, as Lypero-
somum squamatum. On bionomic and morpho-
logical grounds, Odhner ( 1926b) suspected that
the species belongs in Cathaemasia , and Doll-
fus ( 1950) made the definite assignment, Cath-
aemasia squamata. Travassos ( 1951) disagreed,
but despite the superficial and in part erroneous
original description, Dollfus was probably cor-
rect. Von Linstow represented the ovary as post-
testicular but the figure is a schematic represen-
tation and the description, except for the loca-
tion of the ovary, agrees so completely with
the description of Cathaemasia orientalis by
Wesley (1940) from the same host, that the two
may be identical. In this species the ovary is
very small and may be covered by coils of the
uterus. It is probable that von Linstow over-
looked the ovary and described the posterior
lobe of the caudal testis as the ovary. Dollfus
(1950) made the combination Cathaemasia
squamata , and if the two are identical the cor-
rect name of the species is Cathaemasia squa-
mata (von Linstow, 1906) Dollfus, 1950, and
C. orientalis disappears as a synonym.
In his paper, Dollfus (1950) described and
figured a single specimen from the throat of
Ardea goliath as C. hians. Travassos (1951)
studied specimens in the Helminthological Col-
lection of the Instituto Oswaldo Cruz, taken
from throats of Indian storks, Xenorhynchus
asiaticus, which he considered identical with the
specimen described by Dollfus and which he
described as a new species, Cathaemasia dollfusi.
Neither Dollfus nor Travassos referred to the
account by Wesley (1940). However, since C.
dollfusi occurs in Xenorhynchus asiaticus and
the description and figures of C. dollfusi are so
similar to those of Cathaemasia seetali Wesley,
1943, there is a strong presumption that the two
are identical. If this suspicion is correct, C. doll-
fusi is a synonym of C. seetali. Pande, Ahlewalia
& Srivastava (1960) reported five immature
specimens from the throat of X. asiaticus and
Ibis cancocephalus, but specific determination
was limited to Cathaemasia sp.
Elizabeth van den Broek (1960) described a
new species, Cathaemasia variabilis, from the
esophagus of abdim storks, Sphenorhynchus
abdimii, collected in Africa and examined in the
Zoological Gardens of Amsterdam. Macko
(1960) recognized two subspecies of C. hians:
C. hians hians and C. hians longivitellata. A
new species, Cathaemasia skrjabini, was de-
scribed by Leizullaev (1961) from Ciconia ci-
conia taken in Azerbaijan, South Russia. In
this species the vitellaria extend forward to the
level of the genital bursa. If this species is iden-
tical with C. hians longivitellata, as seems prob-
able, the specific name becomes longivitellata
and skrjabini is a synonym. In a second report,
Leizullaev (1962) reported morphological dif-
ferences in C. hians as a result of development
in different intermediate hosts.
Leidy (1891) described a species from the
American osprey, Pandion carolinensis, as Dis-
toma trapezium, a species which Stiles & Hassall
(1894) declared is identical with Distoma reti-
culation Wright, 1879.
Travassos (1916) described Pulchrosoma
pulchrosoma from the abdominal air-sacs of
Megaceryle torquata taken in Brazil and includ-
ed it in the subfamily Omphalometrinae. Har-
wood (1936) redescribed Distoma reticulation
Wright, 1879, from the air-sacs of the belted
kingfisher, Megaceryle alcyon, and assigned the
species to Cathaemasia. Zeliff (1941) described
three specimens from M. alcyon as Cathaemasia
reticulata (Wright, 1879) Harwood, 1936. Ca-
ballero & Llores (1948) described ten specimens
from M. torquata taken in Mexico, similar to
and presumably identical with those of Wright,
as Cathaemasia reticulata. They predicated that
P. pulchrosoma is identical with C. reticulata
and suppressed Pulchrosoma as a synonym.
Manter ( 1949) reported a single specimen from
the body cavity of M. alcyon taken in Nebraska,
and agreed that Pulchrosoma is a synonym of
Cathaemasia. Olsen (1940) described two speci-
mens from the intestine of the black crowned
night-heron, Nycticorax nycticorax, as a new
species, Cathaemasia nycticoracis, but the
worms do not agree with the generic concept
of Cathaemasia and their systematic position is
uncertain.
Travassos (1951) insisted on the validity of
the genus Pulchrosoma and recognized two
species: P. pulchrosoma from M. torquata, and
the species from M. alcyon which he had desig-
nated earlier as Pulchrosoma reticulata (Wright,
1879) Travassos, 1939. The contention of Tra-
vassos is strongly supported since the species of
Pulchrosoma and Cathaemasia differ in mor-
phology, in site of infection, and in the orders
of birds that serve as final hosts. Travassos divid-
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Stunkard & Gandal: New Trematode from Saddle-bill Stork
71
ed the family Cathaemasiidae into two subfam-
ilies: Cathaemasiinae which was ascribed to
Dollfus (there was no reference to Cathaema-
siinae of Wesley), and Ribeiroiinae, a new sub-
family. Cathaemasiinae contained three genera:
Cathaemasia, Pulchrosoma and Cathaemasio-
ides; Ribeiroiinae contained two genera: Ribei-
roia Travassos, 1919, and Trifolium Travassos,
1922.
The genus Cathaemasioides was erected by
Teixeira de Freitas (1941) to contain a new
species, Cathaemasioides callis, from the South
American stork, Euxenura galeata. The location
in the host was not given. Cathaemasioides was
distinguished from Cathaemasia on two fea-
tures: the posterior portions of the digestive
ceca bear short lateral branches and the vitel-
laria do not extend posteriorly beyond the testi-
cular level. These characteristics are hardly ade-
quate to delineate a new generic concept and
the species should be included in Cathaemasia
as Cathaemasia callis (Teixeira de Freitas,
1941) n. comb.
Szidat ( 1 940 ) discussed the parasites of storks
and the evidence supplied by the helminthic and
arthropodal species on the questions of ecology,
phylogeny and ancestral home of these birds.
Evidence supports the idea that the original
home was central Africa, from which they have
dispersed. The species that live in tropical areas
are resident, whereas the white and black storks
are migrants that breed in northern regions and
winter in Africa. Szidat had demonstrated that
these birds become infected with C. hians when
juveniles in their northern range. Concerning
C. hians he observed, p. 565, “Dieser Trema-
tode scheint nur in unseren beiden Storcharten
vorzukommen. Auch die Gattung ist in ihrem
Vorkommen nach alien, was wir wissen, durch-
aus auf Ciconiidae beschrankt.” The species of
Cathaemasia which infect storks resident in
Africa and Asia obviously would use interme-
diate hosts other than those of the migrant storks
whose asexual generations occur in European
snails. It follows that the parasites employ dif-
ferent intermediate hosts in Africa and Europe,
which may accelerate speciation. There are sev-
enteen species of living storks which range from
South America to Australasia and members of
at least ten genera are known to harbor some
ten or twelve species of Cathaemasia. It appears
that the hosts have evolved more rapidly than
their trematode parasites. However, the parallel
distribution of hosts and parasites can hardly
be accidental. The presence of Cathaemasia cal-
lis in the South American storks, Euxenura gale-
ata, is remarkable, in view of the temporal and
geographic separation of New World species.
A further divergence is manifest by the two
species of the genus Pulchrosoma, from the air-
sacs of American kingfishers. They are members
of the Cathaemasiinae, but infect birds of the
order Coraciiformes, distinct from the Ciconii-
formes.
The specimens from Ephipphiorhynchus sen-
egalensis are described as a new species, Cathae-
masia senegalensis. Type and paratype speci-
mens are deposited in the Helminthological Col-
lection of the U. S. National Museum under the
numbers, 60687 and 60688. The specimens
agree better with C. dollfusi than any other
species, but differ from all in the form and loca-
tion of the gonads. In all other species the ovary
is pretesticular, whereas in C. senegalensis the
ovary is situated between lateral lobes of the
anterior testis. In C. senegalensis, the testes are
more branched, more massive, and the branches
interdigitate to such an extent that in most speci-
mens the testes appear to merge.
Literature Cited
Bannerman, D. A.
1953. The Birds of West and Equatorial Africa.
Oliver and Boyd, London.
Braun, M.
1901. Zur Revision der Trematoden der Vogel.
Centr. Bakt., Abt. 1, 29: 895-897.
Broek, Elizabeth van den
1960. Cathaemasia variabilis n. sp. (Trematoda:
Cathaemasiidae) from the esophagus of
Sphenorhynchus abdimii. Jour. Helminth.,
34: 243-246.
Caballero, E., & L. Flores
1948. Parasitismo de Streptoceryle tor quota tor-
quata por Cathaemasia reticulata (Wright,
1879) Harwood, 1936 (Trematoda: Echi-
nostomatidae). Anal. Escula Nacion.
Cien. Biol., 5: 223-227.
Dollfus, R. P.
1950. Trematodes recoltes au Congo beige par
le Professeur Paul Brien (mai-aout, 1937).
Ann. Mus. Belg. Congo, C— Zoologie, ser.
V, 1: 1-136.
Dujardin, F.
1845. Histoire naturelle des helminthes ou vers
intestinaux. Paris.
Feizullaev, N. A.
1961. A new trematode, Cathaemasia skrjabini
n. sp., from Ciconia ciconia in Azerbai-
jan. Dokladi Akad. Nauk Azerbaijan
SSSR., 17: 63-65.
1962. The divergence in two species of trema-
todes, Cathaemasia hians (Rudolphi,
1809) and Chaunocephalus ferox (Ru-
dolphi, 1795) Dietz, 1909, on change of
the intermediate hosts. Dokladi Akad.
Nauk SSSR., 146: 238-241.
72
Zoologica: New York Zoological Society
[50: 7
Fisher, F. M., Jr., & A. F. West
1958. Cercaria megalura Cort, 1914, the larva
of a species of Philophthalmus. Jour.
Parasitol., 44: 648.
Fuhrmann, O.
1928. Trematoda, in Handbuch der Zoologie,
Kiikenthal u. Krumbach, 2: 1-140.
Harwood, P. D.
1936. Notes on Tennessee helminths, III. Two
trematodes from a kingfisher. Jour. Tenn.
Acad. Sci., 11: 251-256.
Leidy, J.
1891. Notices on Entozoa. Proc. Acad. Nat. Sci.,
Philadelphia, 42: 410-418.
Linstow, O. von
1906. Helminthes from the collection of the
Colombo Museum. Spolia Zelanica, 3:
163-188.
Looss, A.
1899. Weitere Beitrage zur Kenntnis der Trema-
todenfauna Aegyptens, zugleich Versuch
einer natiirlichen Gliederung des Genus
Distomum Retzius. Zool. Jahrb., Syst.,
12: 521-784.
Macro, J. K.
1960. Differenzierung von Cathaemasia hians
(Rudolphi, 1809) auf zwei Unterarten,
C. hians hians (Rud. 1809) and C. hians
longivitellata subsp. nov. Helminthol.
Bratislava, 2: 270-275.
Manter, H. W.
1949. The trematode Cathaemasia pulchrosoma
(Travassos, 1916) n. comb, from the
body cavity of a kingfisher (Megaceryle
alcyon) in Nebraska. Jour. Parasitol., 35:
221.
Mendheim, H.
1940. Beitrage zur Systematik und Biologie der
Familie Echinostomatidae (Trematoda).
Nova Acta Leopoldina, n.f. 8 (54): 497-
588.
Muhling, P.
1897. Beitrage zur Kenntniss der Trematoden.
Arch. Naturg., Jahrg. 62: 243-279.
Odhner, T.
1911. Zum natiirlichen System der digenen
Trematoden. IV. Zool. Anz., 38: 513-531.
1926a .Protofasciola n. g„ ein Prototypus des
erossen Leberegels. Arkiv. Zool., 18A
(20): 1-7.
1926b. Zwei neue Arten der Trematodengattung
Cathaemasia Looss. Arkiv. Zool., 18B
(10): 1-4.
Olsen, O. W.
1940. Two new species of trematodes ( Apharyn -
gostrigea bilobata: Strigeidae, and Catha-
emasia nycticoracis : Echinostomidae)
from herons, with a note on the occur-
rence of Clinostomum campanulatum
(Rud.). Zoologica, New York, 25: 323-
328.
Pande, B. P., S. S. Ahlewalia, & J. S. Srivastava
1960. Note on host-parasite relationships ob-
served in fluke infections of wild aquatic
birds. Parasitol., 50: 323-327.
Poche, F.
1926. Das System der Platodaria. Arch. Naturg.,
A. 91:1-240.
Rudolphi, C. A.
1809. Entozoorum sive vermium intestinalium
historia naturalis. Vol. 2. Amstelaedami.
Stiles, C. W., & A. Hassall
1894. A new species of fluke (Distoma [ Dicro -
coelium ] complexion) found in cats in the
United States, with bibliographies and
diagnoses of allied forms. (Notes on para-
sites. 21) Veterinary Mag., 1: 413-432.
Szidat, L.
1939. Beitrage zum Aufbau eines natiirlichen
Systems der Trematoden. I. Die Entwick-
lung von Echinocercaria choanophila U.
Szidat zu Cathaemasia hians und die Ab-
leitung der Fasciolidae von den Echino-
stomidae. Zeit. Parasitenk., 11: 239-283.
1940. Die Parasitenfauna des weissen Storches
und ihre Beziehungen zu Fragen der
Okologie, Phylogenie und der Urheimat
der Storche. Zeit. Parasitenk., 11: 563-592.
Szidat, Ursula
1936. Ueber eine neue Echinostomidencercarie,
Echinocercaria choanophila n. sp. Zool.
Anz., 116: 304-310.
Teixeira de Freitas, J. F.
1941. Cathaemasioides callis n. g., n. sp., trema-
todeo parasito de Euxenura galeata
(Molina). Mem. Oswaldo Cruz, 35: 489-
492.
Travassos, L.
1916. Informagoes sobre a fauna helmintologica
sul fluminense II. Brasil. Med., 30: 312-
314.
1951. O genero Pulchrosoma Travassos, 1916
e sua situagao no sistema de trematodeos.
Arq. Zool. Estado S. Paulo, 7: 465-492.
Wesley, W. K.
1940. Studies on the Indian species of the genus
Cathaemasia Looss with discussion on the
family Cathaemasidae Fuhrmann, 1929.
Proc. Nat’l Acad. Sci., India, 10B: 31-40.
1943. On a new species of the genus Cathaemasia
Looss. Proc. Nat’l Acad. Sci., India, 13:
328-332.
1965]
Stunkard & Gandal: New Trematode from Saddle-bill Stork
73
Yamaguti, S.
1958. Systema Helminthum. Interscience, New
York.
Yoshida, S., & K. Toyoda
1930. Notes on Cathaemasia hians (Rudolphi)
from the mouth of Ciconia nigra. Ann.
Trop. Med. Parasitol., 24: 85-94.
Zeliff, C. C.
1941. Observations on Cathaemasia reticulata,
a trematode from the belted kingfisher.
Amer. Natur., 75: 508-512.
8
A Device for the Sonic Tracking of Large Fishes
George A. Bass & Mark Rascovich
The American Museum of Natural History
(Plates I & II: Text-figures 1-5
Introduction
SINCE a device which would enable one to
follow the movements of unconfined and
untethered fishes would have value in
studies concerned with both their short term
movements and their larger migratory travels,
efforts were made to develop such an instrument.
A variety of possible solutions was considered,
finally settling on some sonic means as potenti-
ally most capable of practical development. The
sonic tracking transmitter, to be attached to a
fish, and the receiver, to be carried by a boat
fast enough to keep the fish under study within
range, comprise the system as developed. Speci-
fications of the system and the results of trials
on fishes are given.
We wish to express our appreciation to the
following: Dr. Sidney R. Galler, Head, Biology
Section, Office of Naval Research, for advice
and counsel; Mr. Frank Mather, III, Research
Fellow, Woods Hole Oceanographic Institution,
for fisheries and fish tagging information; Mr.
Frank M. Vargo, Chief Engineer, Airtronics In-
ternational Corporation, for electronic develop-
ment and applications; Mr. John Rybovich,
Rybovich Boat Co., and Mr. Jack Hargrave,
Naval Architect, for marine design; Capt. C. C.
Anderson, Palm Beach, Florida, operator of the
tracking boat, who was of great assistance dur-
ing the tests; and the management of the Lerner
Marine Laboratory for facilities in connection
with preliminary tests.
The development of this system has been sup-
ported in part by O. N. R. Contract Nonr
552(04) NR 301-257 held by C. M. Breder, Jr.,
of The American Museum of Natural History,
and in part by the George A. Bass Fund.
System Specifications
The transmitter consists of an aluminum
cylinder, 2 Vi" o.d. X lCPA" long, with a barium
titanate transducer molded into one end. See
Text-fig. 1. This transmitting package is de-
signed to withstand depths of 900' and weighs
34 ounces in seawater. The tracking signal radi-
ated by the transmitter consists of pulsed ultra-
sonic energy with a frequency of 38 KC and a
pulse duration of 50-100 milliseconds; the rep-
etition rate is one pulse every two seconds.
Power is provided by a 13-volt mercury battery
with a life of 150 hours and provides 12 watts
input to the transducer. It is streamlined, painted
a mat gray-green, and is attached to the fish by
means of barbed prongs with the transducer
facing aft for proper tracking configuration.
See Plate I, Fig. 1, and Text-fig. 2 for the
schematic.
Receiving transducers aboard the tracking
vessel are two in number, of barium titanate, and
mounted adjacent to a pre-amplifier in a ten-
foot-long hydrofoil boom fabricated out of al-
uminum. This boom is faired out over its lower
six-foot portion to provide a smooth hydrofoil
section over its submerged part. The transducers
are molded individually in rubber and mounted
with the axis horizontal and located at 90 de-
grees with respect to each other. Sound-absorb-
ing material surrounds each transducer, leaving
only the front face exposed to couple with sea-
water. Liquid rubber was used as an over-all
finishing coat to provide additional protection
and a smooth exterior surface. The transducers
are sufficiently unidirectional in their response
and are connected to the input of the dual chan-
nel, low noise, narrow band pre-amplifier. To
75
76
Zoologica: New York Zoological Society
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further reduce extraneous noise at this point,
the pre-amplifier has its own battery power
supply carried in the upper portion of the boom.
The pre-amplifier has a usable input sensitivity
of 2 microvolts with low impedance outputs to
match the 50 ohm coaxial cable used to connect
it to the receiver unit on the bridge or in the
cockpit. When in operation, the unit is mounted
vertically from the bow of the boat, usually
through a strong pulpit, and secured by welded
metal bracing, its lower end submerged ahead
of the bow-wave and 4-6 feet below the surface.
All fittings securing it to the boat are gasketed
with rubber insulation to guard against ship
noise and vibration. See Plate I, Figs. 2 and 5,
and Text-fig. 3 for the schematic.
The shipboard receiver is housed in a spray-
tight metal cabinet with a gasketed, removable
lid. All operating controls are mounted on a
subpanel accessible when the lid is removed. A
compartment is provided for a 12-volt battery
which powers the unit, and for accessories. The
receiver consists of a dual channel, narrow band
amplifier with low impedance output to match
the pre-amplifier. It is completely shielded to
minimize pickup from the boat’s electrical sys-
tem. The main operating controls consist of a
“Power On” switch, dual ganged “Gain” con-
trol, “Tone” control, “Range” sensitivity con-
trol, “Direction” sensitivity control, and “Vol-
ume” control. A visual signal read-out is
provided by a zero center meter which gives
directional information by deflecting either left
or right; a second meter gives an indication of
range by measuring strength of signal. Aural
read-out is obtained from a set of stereo head-
COMPONENT PARTS LIST
Cl — Subminiature electrolytic capacitor, 10 mfd/15v.
C2 — Subminiature electrolytic capacitor, 50 mfd/15v.
C3, C6 — Molded plastic capacitor, .033 mfd/50v.
C4 — Molded plasiic capacitor, .0047 mfd/50v.
C5 — Molded mica capacitor, 100 mmfd/200v.
Cl — Subminiature electrolytic capacitor, 200 mfd/15v.
D1 — Silicon diode, 100 MA/30v.
D2 — Silicon diode, 500 MA/50v.
K1 — Sensitive relay, S.P.D.T., 6V Coil.
LI — Adjustable inductor, 4.0 mil.
Q1 — Silicon NPN transistor, 200 mw.
Q2 through Q5 — Germanium PNP transistor, 200 mw.
Q6, Q7 — Silicon NPN transistor, lOw.
Rl, R5 — Molded composition resistor, 100Kohm/*/2W.
R2 — Molded composition resistor, lOKohm/’/iw.
R3, R7 — Molded composition resistor, 4.7Kohm/1/2W.
R4 — Molded composition resistor, 22K.ohm/'/2W.
Rfi — Molded composition resistor, lOOohm/'/^w.
R8, R9 — Molded composition resistor, 47ohm/,/iw.
R10 — Molded composition resistor, 12ohm/'/2w.
T1 — Driver transformer, 200ohm Pri. Imp., SOOohm CT Sec.
Imp.
T2 — Output transformer, 48ohm CT Pri. Imp., SOOohm Sec.
Imp.
Xducer (Transducer) — Barium titanate, cylindrical, molded
in rubber.
Z1 — Zener diode, 7.5v/lw.
1965]
Bass & Rascovich: A Device for Sonic Tracking of Large Fishes
77
COMPONENT PARTS LIST
Cl, C2 — Subminiature electrolytic capacitor, 10 mfd/3v.
C3, C4 — Subminiature electrolytic capacitor, 10 mfd/15v.
C5 through C8 & 03 through 08 — Ceramic disc capacitor,
0.1 mfd/50v.
C9, CIO — Molded mica capacitor, 500mmfd/200v.
Cll, 02 — Molded plastic capacitor, .008 mfd/50v.
09, C20 — Subminiature electrolytic capacitor, 100 mfd/15v.
C21, C22 — Subminiature electrolytic capacitor, 2 mfd/15v.
Dl, D2 — Silicon diode, 500MA/50v.
LI, L2 — Adjustable inductor, 2.5 mh.
L3, L4 — Adjustable inductor, 2.0 mh.
Q1 through Q10 — Germanium PNP transistors, 200 mw.
Rl, R2, R17, R18, R25, R26, R33, R34 — Molded composition
resistor, lKohm/l^w.
R3, R4 — Molded composition resistor, 22Kohm/Viw.
R5, R6, R9, RIO, R23, R24 — Molded composition resistor,
2.2Kohm/I/4w.
R7, R8 — Molded composition resistor, 220ohm/1/2\v.
Rll, R12, R31, R32 — Molded composition resistor, 100-
ohm/Viw.
R13, R14, R19, R20 - Molded composition resistor, 82-
Kohm/Vi w.
R15, R16, R21, R22, R29, R30 — Molded composition re-
sistor, lOKohm/Vivv.
R27, R28 — Molded composition resistor, 68Kohm/'/2w.
Xducer (Transducer) — Barium titanate, cylindrical, molded
in rubber.
phones and supplements that given by meter.
See Plate I, Fig. 3, and Text-fig. 4 for the sche-
matic.
The system, shown in Text-fig. 5 in block
diagram form, is designed primarily for use on
small boats of the sport fishing type, the one
used for all testing and tracking having been
only 32 feet over-all. Self-contained power
makes operation independent of the boat’s elec-
trical supply.
A useful accessory for emergency use when
the signal is either lost or too marginal for an
accurate bearing, is the hand-held “snifter.” This
is a single-transducer hydrophone mounted on
one end of a 9-foot-long. 1 Vi " aluminum tube,
a power supply, switch, and pre-amplifier boxed
in the opposite end, and connected to the ship-
board receiver by a length of coaxial cable. See
Plate I, Fig. 4. This lightweight unit can be held
over the side of the boat with the transducer
submerged, and rotated by hand when the track-
ing vessel is stopped; it has proved to be ex-
tremely sensitive. For inshore tracking in bays
or estuaries, .it can undoubtedly be used as the
main receiving transducer from small skiffs and
outboards if neither speed nor wave action is
of any consequence.
The over-all performance of the present sys-
tem is satisfactory for a tracking range of IV2 +
miles through sea-state 3 and at a speed of up
to 10 knots. At reduced speed with subsequent
reduction in extraneous noise in the system, the
range quickly builds up to better than 2 miles.
The range may be increased still further to ap-
proximately 10 miles by boosting the power out-
put of the transmitter, but this will, of course,
reduce its life.
Equipment Development
Development of this tracking system was
started in 1959 and continues through the pres-
ent. Prior to that time, limited sonic tracking
of salmon had been accomplished in rivers and
estuaries over short ranges and time periods.
See, for instance, Trefethen and colleagues.1
Marine tracking under oceanic conditions, in-
volving far greater distances and durations, pre-
sented a different and more complex set of
problems, the solution of one often compromis-
ing the solution of another. While the sonic tag
1Trefethen, P. S. 1956. U. S. Fish and Wildlife Serv.,
Special Sci. Rept. Fisheries No. 179, 11 pp.
Trefethen, P. S., J. W. Dudley & M. R. Smith. 1957.
Electronics, Vol. 30, No. 4, pp. 156-160.
78
Zoologica: New York Zoological Society
[50: 8
Text-fig. 4. Schematic of the shipboard part of the receiver.
COMPONENT PARTS LIST
BFO — Beat frequency oscillator, adjustable 36 KC to 40 KC.
Cl, C2 — Subminiature electrolytic capacitor, 5 mfd/15v.
C3 through C6, C9, CIO, C24, C25 — Ceramic disc capacitor,
0.1 mfd/50v.
C7, C8 — Molded plastic capacitor, .03 mfd/50v.
Cll, C12 — Subminiature electrolytic capacitor, 10 mfd/15v.
C13. C14 — Subminiature electrolytic capacitor, 100 mfd/15v.
C15, C16 — Molded plastic capacitor, .04 mfd/50v.
C17, C18 — Molded plastic capacitor, .005 mfd/50v.
C19, C20 — Molded mica capacitor, 500 mmfd/200v.
C21, C22 — Molded plastic capacitor, 1.0 mfd/50v.
C23 — Molded plastic capacitor, .0047 mfd/50v.
Dl, D2 — Silicon diode, 500 MA/50v.
FI, F2 — Filter, Bridged “T", Adjustable 36 KC to 40 KC.
LI — Adjustable inductor, 4.0 mil.
Q1 through Q13 — Germanium PNP transistors, 200 mw.
Rl, R2, R7, R8, R1 1, R12, R19, R20, R25, R26, R39 through
R44 — Molded composition resistor, lOKohm/I^w.
R3, R4. R9, R10, R34, R37, R38 — Molded composition re-
sistor, 100Kohm/'/6w.
R5, R6 — Dual concentric potentiometer, lKohm/!/2w.
R13, R14, R27, R28, R36 — Molded composition resistor,
IKohm/Viw.
R15, R16, R23, R24, R47, R48 — Molded composition re-
sistor, 100ohm/'/2W.
R17, R18 — Molded composition resistor, 47Kohm/!/2\v.
R21, R22 — Molded composition resistor, 470ohm/1/iw.
R30 — Molded composition resistor, ISKohm/Viw.
R31 — Molded composition resistor, 8.2Kohm/*/6w.
R32 — Molded composition resistor, 3.9Kohm/*/2 w.
R33 — Molded composition resistor, 680ohm/1/2W.
R35 — Molded composition resistor, 22Kohm/’/2W.
R45, R46 — Potentiometer, lOKohm/’/iw.
R49, R50 — Molded composition resistor, 47ohm/!/2W.
T1 T2 — Input transformer, adjustable 36 KC to 40 KC.
was designed for large fish of 250 lbs. and over,
miniaturization of the transmitting unit re-
mained difficult because anything less than 150
hours of transmitter life was not considered
practical for the project. Mercury batteries pro-
vided a solution to this problem. In general, how-
ever, less difficulty was experienced with the
transmitter than with the receiving components
of the system and its design has remained the
same since 1961.
Obviously the system described herein is to be
considered a step in the rapidly moving fields of
electronics and underwater supersonics which,
it is hoped, will eventually lead to much more
sophisticated instrumentation. The present model
provides no direct data on the depth at which
the fish may be located. This could be accomp-
lished by introducing some pressure transducer
approximately affecting the pulse rate or other
feature of the signal, but only at the expense of
greater bulk. The size of the transmitter could
be reduced but at the cost of shortening its life.
This may be of more importance than generally
thought, since Clancy ( 1963) 2 has shown that
2Clancy, D. W. 1963. Jour. Fish. Res. Bd. Canada,
Vol. 20, No. 4, pp. 969-981.
1965]
Bass & Rascovich: A Device for Sonic Tracking of Large Fishes
79
even a one-half-inch disc tag reduces swimming
speed in six-inch salmon fingerlings by about
50%.
Early models of the system were tested at sea
by towing an activated transmitter at various
depths and speeds while a tracking vessel
checked out the receiver system. By this method,
weaknesses in the housing and handling of the
receiving transducers quickly became evident
and a number of methods and designs were
tested and rejected. While excellent range char-
acteristics could be obtained when either stopped
or operating at very low speeds in a flat sea,
ambient noises with concurrent loss of range
quickly built up when speed and sea-state in-
creased. The ship’s noise proved by far the most
vexing engineering problem. Light, easily han-
dled “rods” supporting the transducer housings
were invariably too fragile and subject to high-
frequency vibrations when under way. Free-
towed underwater vehicles of delta-wing design
were too difficult to handle with the gear avail-
able on a small boat and also proved unsatis-
factory in tight maneuvering. The fixed, rigid
hydrofoil boom used in the tuna tests of May-
June, 1963, evolved from several earlier models
and turned out to be the most dependable for
both sturdiness and “silent operation.” However,
it is not considered the final solution and pre-
sents difficulties which will be discussed later.
The signal’s frequency of 38 KC, presumably
beyond the range of fish hearing, was chosen
because (at the time) it was compatible with
available electronic components, and tests made
in the fish pens at the Lerner Marine Labor-
atories caused no apparent reactions on available
marine species, even when radiated at powers
above 10 KW. Lower frequencies will, of course,
have greater range and penetration, but the
power required and the increased size of the
transducer made their use impractical in this
case.
Trials on Fishes
The following protocol of tests made directly
on fishes indicates both the manner in which it
was possible to handle the fishes and the type
of information they may be expected to produce.
Three species were used: Carcharhinus sp.,
probably C. milberti (Muller & Henle) ; Sphyrna
zygaena (Linnaeus); and Thunnus thynnus
(Linnaeus) .
Trials on Carcharhinus
An estimated 300-pound shark was released
with the sonic capsule off Jupiter Inlet, Florida,
in less than 30 fathoms. It was tracked for four
hours. After an initial run of about one-quarter
mile it settled down to cruising in various depths
between 15 and 21 fathoms. It followed a criss-
cross pattern in an area of about one square
mile at a speed of about three knots. The area
of this activity could well represent its normal
home territory. The distance from shore varied
between four and six miles.
Trials on Sphyrna
An estimated 300- to 350-pound hammerhead
was released with a transmitter three miles off
Palm Beach, Florida, over 60 fathoms, on April
16. After some initial meandering, the shark
headed in a generally easterly direction, at a
speed averaging about three knots. It was fol-
lowed for two hours, the tracking boat’s position
then being nine miles east-northeast of Palm
Beach Inlet.
Trials on Thunnus
All tuna work was carried out during late
May, 1963, out of Cat Cay, Bahamas. Sonic
capsules were attached to three tuna.
An individual of about 400 lbs. was caught
approximately five miles west of Gun Cay on
(xMTR.tm — nf) —
DIRECTIONAL READOUT
(VISUAL)
STEREO
PHONES
80
Zoologica: New York Zoological Society
[50: 8
May 24 in about 120 fathoms. It was released
immediately after the transmitter was attached
and sounded at once. Visual observation was
possible only for a few seconds when the tuna
was seen diving at high speed with a white-tip
shark, Carcharhinus longimanus (Poey)?, in
close pursuit. The tracking boat had been wait-
ing some 500 yards away and immediately
picked up a strong tracking signal. The tuna
evidently escaped the shark because, after its
initial fast run, it began swimming deep on an
erratic course which generally followed wide
circles of roughly half-mile diameter. This pat-
tern showed a northerly drift at first, but after
about fifty minutes the fish moved in a generally
southwesterly direction. Its speed varied a great
deal, between 3-12 knots, with frequent devia-
tions from its course, all of which made tracking
somewhat difficult. However, although the signal
occasionally became marginal, it was possible to
follow the fish. Tracking of this particular tuna
lasted one hour and seven minutes and was term-
inated because of a collapse of the hydrofoil
boom. This was caused by an unexpected wave,
possibly a wake from one of the many fishing
cruisers speeding about the area, which damaged
the supporting bracing of the hydrofoil boom.
A second tuna of about the same size as the
first, captured three miles northwest of Sand
Cay in about 15 fathoms, was similarly re-
leased on June 10, except that no sharks were
seen. The tracking boat was approximately 300
yards away and picked up a strong signal. It
was easily followed as the fish headed westerly
toward the Gulf Stream, about a half-mile dis-
tant, at approximately seven knots. After about
seven minutes the signal stopped abruptly. There
was no fading, as would be expected if the fish
had merely outdistanced the boat.
A third tuna was released with a transmitter
about two miles west of Little Cat Cay and be-
haved in a closely similar manner, except that
it showed a greater flurry of activity at the re-
lease and then quickly settled westerly toward
the Gulf Stream, about three miles away. Once
it reached deep water, it changed its course to
a steady southwest. The speed remained fairly
high, between 8 and 10 knots, with occasional
faster bursts. After two hours and fifteen min-
utes, over 20 miles offshore, the fish was being
followed at distances which varied from 500
yards to Wi miles through sea-state 3. At no
time did the signal even become marginal and
there was never any question as to the location
of the tuna ahead of the boat. Undoubtedly
tracking could have been continued for con-
siderable time and distance, but oncoming dark-
ness, the distance from Cat Cay and the fact
that the boat was not suited for extended stays
at sea caused a termination of the trail at this
point. The signal continued to be heard for more
than ten minutes after the course had been re-
versed.
Discussion
The tracking experiments on tuna off Cat
Cay and of two sharks in Florida waters, and
some twenty-five “sled tests” with towed tags,
have proved the feasibility of the basic system.
In its present stage of development it can be
useful in gathering ecological data and can con-
tribute to the study of behavior patterns of mar-
ine animals. The following details concern
various items which it is thought would be of
use to anyone undertaking similar developments.
Method of Housing and Handling the Re-
ceiving Transducers.— While the present design
of a hydrofoil boom carried ahead of the bow
wave worked satisfactorily, it had certain in-
herent limitations. Naturally, extremely rugged
bracings are necessary for deep-sea work. These
restrict the maneuverability of the boat to some
extent. For safety reasons, the entire unit must
be easily and quickly detachable. This model
was fixed in position, but a turnable one would
be much better, although vastly complicating
the design. Through-the-hull types of retractable
and trainable housings have been considered and
might well be more suitable for permanent in-
stallations, but the hull noise factor would be a
critical consideration. For long range deep-sea
tracking, it is probable that a combined system
of fixed installation and towed vehicle will prove
to be the most practical.
The loss of the second tuna was caused by
the failure of the boom bracings, which origin-
ally were made of aluminum. These were re-
placed by channel iron.
Recording.— The present system depends on
the tracking vessel’s crew for recording of the
movements of the fish. It obviously could be
coupled to an automatic course recorder, yield-
ing a permanent graph and tracing of the entire
operation.
Recoverable Transmitters.— The present trans-
mitters are quite expensive and become (so far)
a total loss after use on a pelagic fish. If the
transmitting part were given positive buoyancy
and were fastened to the attachment part by
water soluble glue or an electromagnet, it could
be released from the fish after a predetermined
period, with a good chance of recovery.
Attaching the Transmitter.— It was found that
in the handling of the tuna, at least, it was more
convenient to have several boats fishing and the
tracking boat hovering nearby to come up to
1965]
Bass & Rascovich: A Device for Sonic Tracking of Large Fishes
81
whichever boat hooked a fish. After the fish
had been brought alongside and the line passed
to the crew of the tracking boat, the transmitter
was attached just as soon as the fish had quieted
enough to make attachment possible. This was
accomplished as shown in Plate II, by a quick
thrust, which imbedded the four miniature “lily
irons” with which the capsule was provided.
The device was placed in the area shown so that
no vital organs would be damaged. The pole
on the end of which the capsule was attached
was withdrawn.
Summary
1. A system for tracking large (over 250
lbs.) fishes by sonar is described; it consists of
a transmitter attached to the fish, a boat-borne
receiver and a sensitive special sensor for use
near the instruments’ range limit.
2. The transmitter is supplied with 12 watts
for about 150 hours from self-contained bat-
teries which provide sonar pulses of 50 to 100
milliseconds every two seconds at 38 KC.
3 . The receiver has two hydrophones mounted
rigidly underwater and so placed and angled
that the signal from them makes it possible to
head the boat toward the transmitter-carrying
fish, by means of the vessel’s steering system.
4. A zero-centered meter and stereo ear-
phones deliver the output from the receiver,
which make tracking possible for distances of
1.5 to 2 miles, depending on the speed of the
boat and the state of the sea.
5. Tests with sharks and tuna proved that it
was fully practicable to follow such a trans-
mitting fish by means of this system.
Zoologica: New York Zoological Society
[50: 8: 1965]
EXPLANATION OF THE PLATES
Plate I
Fig. 1. The transmitter capsule ready for attach-
ing to a fish. The sonic transducer is to
the left.
Fig. 2. The submergible part of the two receiving
transducers, imbedded in their sound-pro-
tective matrix.
Fig. 3. The shipboard end of the receiving system,
showing both aural and optical indicators.
Fig. 4. The hand-held sonic detector of superior
sensitivity for use in marginal areas.
Fig. 5. The boat used for tracking, showing the
boom supporting the submerged sensors,
ahead of the prow.
Plate II
Fig. 6. The manner in which the sonic capsule is
attached to a fish.
Fig. 7. A tuna, just before release, showing the
capsule attached.
BASS 8c RASCOVICH
PLATE I
FIG. 3 FIG. 4
FIG. 5
A DEVICE FOR THE SONIC TRACKING OF LARGE FISHES
BASS & RASCOVICH
PLATE II
FIG. 6
FIG. 7
A DEVICE FOR THE SONIC TRACKING OF LARGE FISHES
9
Studies on Virus Diseases of Fishes. Spontaneous and Experimentally
induced Cellular Hypertrophy ( Lymphocystis Disease) in Fishes
of the New York Aquarium, with a Report of New Cases
and an Annotated Bibliography (1874-1965)
Ross F. Nigrelli & George D. Ruggieri, S. J.
New York Aquarium
(Plates I-X)
LYMPHOCYSTIS disease, a non-lethal viral
disease first (25) observed in Euro-
J pean flounder in 1874, is characterized
externally by the development of nodules on the
fins and skin (Figs. 1-5, 7-9); the growths may
also appear as tumor-like masses (Fig. 6) or as
flat, confluent patches in various parts of the
body (Figs. 10, 11). The lesions have a granular
appearance due to numerous white, spherical or
oval, tremendously enlarged connective tissue
cells, lying singly or in groups in lymph spaces
below the stratified epithelium (Figs. 12, 13, 14,
20, 23). These giant cells may also be found
in the gills, pharynx, ovary, spleen and in the
walls of the heart and gastro-intestinal tract
(7, 35); the lymphocystis cells in these organs
are probably displaced elements but their devel-
opment in situ (Fig. 14) is possible. The lymph-
ocystis cells are considered to be enlarged trans-
formed fibroblasts (24, 63-67), but the possi-
bility that they are hypertophied osteoblasts or
histiocytes is not excluded.
The transformed connective tissue cell, which
may enlarge from 10-15 microns to 500 microns
or more (an increase in volume of about a mil-
lion times) is typically surrounded by a hyalin
capsule (Figs. 14, 17, 18). The cell contains an
enlarged nucleus usually in various stages of
karyorrhexis, one or more enlarged nucleoli
and a densely granular, sometimes vacuolated,
cytoplasm with basophilic, Feulgen-positive (19)
inclusions, which may appear as a single, branch-
ing, perinuclear network or as several vacuolated
plaques (Figs. 1 3-23 ) . The inclusions arise from
one or more Guarnieri-like bodies, usually seen
in the smallest infected cells ( 1, 63, 64, 72, 73) .
Basophilic granules or rods that develop from
the surface of the inclusions (74, 75, 76, 83-86)
are readily visible as osmiophilic granules with
the light microscope, and show characteristic
viral morphology in electron-microscopic prep-
arations (58, 60, 61). The osmiophilic particles
may also be found in the nucleus and/or free
in the cytoplasm of the enlarged cell (86). The
inclusion particles, readily visible in ordinary
histological preparations (Figs. 18, 24), suggest
a cytomegalovirus.
Although lymphocystis disease is recognized
in general by the enlargement of the connective
tissue cell, gross and subtle species or family
similarities or differences are apparent in certain
cellular details (Figs. 13, 15,20, 23, 25), which
have not as yet been characterized. Some obvi-
ous differences are 1 ) maximum size that the
infected cell can attain, 2) origin, structure and
distribution of the basophilic inclusions, and 3)
the electron-microscopic morphology and size of
the virus particles.
Cellular distention appears to be a character-
istic feature in certain viral infections in higher
vertebrates (11). The enlargement in these in-
stances is moderate when compared to the
lymphocystis cell1 which, in some cases ( e.g .,
in diseased cells of the European flounder), can
increase a million-fold or more in volume. The
factors responsible for this tremendous enlarge-
ment have not been determined but cannot be
explained solely on viral multiplication, since
the amount of basophilic inclusions varies con-
1“Glugea-cysts” is another form of cellular gigan-
tism, but caused by intracellular protozoan parasites
belonging to the Microsporidia (68, 69, 81).
83
84
Zoologica: New York Zoological Society
[50: 9
siderably with the host cells of similar size in
the same lesion. Some of the increase in size
may be due to imbibition.
The histopathological changes associated with
the development of the hypertrophied cells are
usually mild (34-35). Early changes are mani-
fested by varying degrees of inflammatory re-
sponses. In more advanced stages of the disease,
the inflammatory reaction disappears and is re-
placed by a mild development of collagenous
fibers. Later, the overlying epithelium, which
may or may not be hyperplastic, is sloughed.
The contents of the cells eventually empty,
leaving only collapsed membranes and fibrous
tissue; healing, however, is usually complete with
no evidence of infection or scar tissue.
The origin and exact nature of the hyalin
capsule, a distinctive feature of the lymphocystis
cell, has not been firmly established. This mate-
rial is PAS-positive (Fig. 26), indicative of
mucoproteins, and the evidence suggests that it
is secreted by the individual infected connective
tissue cell (Figs. 14, 17), even though the cell
itself appears to be PAS-negative (Fig. 26).
When the cells are immediately adjacent to each
other, the membranes become fused (Figs. 16,
20) or form, as in the case of the extreme de-
velopment of lymphocystis cells in the striped
bass, a diffused gelatinous-like matrix (Fig. 25).
The infectious nature of the disease, first rec-
ognized by Weissenberg (63) more than fifty
years ago, was repeatedly demonstrated by him
(64-67, 71-73, 79-80, 87) and others (33), and
especially by the meticulous infection experi-
ments by Rasin (43, 44) 2 and more recently by
Wolf (93) and co-worker (94). The viral etiol-
ogy proposed by Weissenberg (63) in 1914,
and long accepted as the cause of lymphocystis
disease purely on circumstantial evidence (11,
18, 33, 50, 51), was finally and firmly estab-
lished in recent years by filtration and trans-
mission experiments (79, 93, 94), and the virus
particles identified and verified by the excellent
electron-microscopic studies by Walker and his
collaborators (58-61). Diseased tissue (virus)
retains its infectivity even after storage at —20°
C for two years, after desiccation of 105-days-
old nodules over KOH for six days at 18-20° C,
and after putrefaction in aquarium water for
five days at 18-20° C. Further, a saline suspen-
sion of emulsified lymphocystis tissue has been
found to be infective in dilution up to 1 : 1
million (43, 44). The virus is glycerol- and
ether-sensitive (93).
2Rasin also transmitted the disease from paradisefish
to giant gourami, this being the first successful inter-
generic transmission.
It is assumed that under natural conditions
the disease is transmitted by the ingestion of
lymphocystis cells or by contact with the con-
tents that may be released into the environment
when the cells burst (77). It has been suggested
that the virus gains entrance into a new suscepti-
ble host by way of the gills (73, 80) but fishes
that are scarred or possess open wounds are
definitely more susceptible (37, 43, 44, 93).
Protozoan, helminthic and crustacean (cope-
pods and argulids) ectoparasites, including
blood-sucking leeches, may play a direct role
in the transmission of the disease, or the lesions
caused by these parasites may be the foci for
the penetration of the virus.
In so far as is known. Table I lists the host
species in which lymphocystis disease has been
reported (see annotated bibliography) . It is quite
evident from this table that the members of
the Order Perciformes, or perch-like fishes, are
especially susceptible. This, however, may not
reflect a true picture, since the Perciformes is the
largest order of fishes, comprising more than
160 families in several sub-orders. Forty-nine
species of fishes, from 5 orders and 20 families,
have been thus far reported in which the disease
had developed spontaneously. Of interest in this
list is the report by Templeman (53) that the
disease also occurs in the North American plaice
(Hippoglossoides platessoides), the first instance
in a flatfish species from the western Atlantic.
The following species in the New York Aquar-
ium’s collection are also new hosts for the dis-
ease: Morone americana (Fig. 10) from Tom’s
River, N J., Lepomis pallidus from Connecticut,
Angelichthys ciliaris from Florida, Forcipiger
longirostris (Fig. 9) from Hawaii, Aequidens
pulcher from Trinidad and Scatophagus argus
(Fig. 3) from the Indo-Pacific. A second case
of the disease in Symphysodon discus (Fig. 1)
is also included.
Most of the species reported in Table 1 repre-
sent isolated cases, but relatively high incidence,
sometimes reaching epizootic proportions, have
been reported for flounders and other flat fishes
in the English Channel, Irish, North, Baltic,
Barents and Arctic Seas (5, 8, 36, 42) and for
the perch or ruff (8, 64) from the streams of
Middle and Northern Europe, including the
brackish shores of the Baltic (Fig. 5). In North
America, the disease is quite common in crappies
from the eastern part of the United States (17,
91), and especially in the economically impor-
tant walleye or pike perch from the Great Lakes
and other lakes in which this species occurs (7,
16, 37, 46, 56, 72). Although the disease is
not lethal, the affected walleyes are unsightly
and are discarded by commercial fishermen. In
1965]
Nigrelli & Ruggieri: Studies on Virus Diseases of Fishes
85
Table 1. Spontaneous Lymphocystis Disease: Host List
(M, Marine; B, Brackish; F, Freshwater; *, New Records)
Species
Common Name
Locality
Author
Class: Teleostomi
Subclass: Actinopterygii
I. Order: Clupeiformes
(1) Family: Osmeridae
1 . Osmerus eperlanus ( B )
European Smelt
North and
Baltic Seas
2, 14
II. Order: Cyprinodontiformes
(2) Family: Cyprinodontidae
2. Fundulus heteroclitus ( B )
Common Killifish
North Atlantic
71
III. Order: Perciformes
(3) Family: Serranidae
3. Roccus lineatus (B)
Striped Bass
North Atlantic
32 (N.Y.A.)i
4 . Serranus atricauda (M)
Mediterranean
41
5. Morone americana* (B)
White Perch
Eastern U.S.
(N.Y.A.)2
(4) Family: Centrarchidae (F)
6. Lepomis gibbosus
Pumpkinseed Sunfish
Eastern U.S.
32, 73 (N.Y.A.)
7. L. macrochirus
Bluegill Sunfish
59-61,73,92-94
(N.Y.A.)3
8. L. pallidus *
(N.Y.A.)4
9. L. humilis
Red-spotted Sunfish
31, (N.Y.A.)
10. L. megalotis
Long-ear Sunfish
50, 73
11. L. cyanellus X L. macrochirus
Blue-spotted x Bluegill
73
12. Pomoxis annularis
White Crappie
17, 91 ( N.Y.A.)5
13. P. nigromaculatus
Black Crappie
17, 73, 91, (N.Y.A.)5
14. Micropterus pseudaplites
False Large-mouth Bass
73
15. M. (Huro) salmoides
Large-mouth Bass
73 (N.Y.A.)6
(5) Family: Percidae
16. Acerina cernua (B)
Ruff or European Perch
Baltic and
North Seas
2, 8, 63, 64
74, 85 (N.Y.A.)7
11. Perea flavescens (F)
Yellow Perch
Eastern N.A.
54
18. Stizostedion vitreum (F)
Walleye or Pike-perch
6, 7, 12, 16, 18, 26,
31,33,37, 38,46,
54-60, 62, 72, 74
79, 80, 85, 92 (N.Y.A.)8
19. S. canadensis griseus (F)
Sauger
7
20. S. glaucum (F)
Blue Pike
7
(6) Family: Mullidae
2 1 . Mullus surmuletus (M)
Red Mullet
English Chan.
1,2
(7) Family: Sparidae
22. S argus annularis (M)
Sargo
Adriatic Sea
8, 14, 23, 24
(8) Family: Chaetodontidae (M)
23. Chaetodon striatus
Banded Butterfly Fish
Florida and
Bahamas
31 (N.Y.A.)
24. Pomacanthus arcuatus
Black Angelfish
31,32,78 (N.Y.A.)
25. Pomacanthus paru
French Angelfish
78
26. Angelichthys isabelita
Blue Angelfish
30, 52 (N.Y.A.)
27. Angelichthys ciliaris*
Queen Angelfish
(N.Y.A.)9
28. Forcipiger longirostris *
Forceps Fish
Hawaii
(N.Y.A.)
(9) Family: Pomacentridae (M)
29. Amphiprion percula
Common Clownfish
S. Pacific
9, 30 (N.Y.A.)
30. Premnas biaculeatus
Spiny Clownfish
9, 49
(10) Family: Scatophagidae
31. Scatophagus argus* (B)
Scat
Indo-China
(N.Y.A.)
(11) Family: Cichlidae (F)
32. Cichlosoma synspilum
Guatemala
78, 88
33. Aequidens portalegrensis
Port or Black Acara
S. America
33 (N.Y.A.)10
34. Aequidens pulcher*
Blue Acara
Trinidad
(N.Y.A.)10
86 Zoologica: New York Zoological Society [50: 9
Table 1. Spontaneous Lymphocystis Disease: Host List— (continued)
(M, Marine; B, Brackish; F, Freshwater; *, New Records)
Species
Common Name
Locality
Author
35. Syrnphysodon discus
Discus; Pompador Fish
S. America
40 (N.Y. A.)
(12) Family: Labridae
36. Lachnolaimus maximus (M)
Common Hogfish
Florida
2, 89 (N.Y.A.)
(13) Family: Blennidae
37. Hypsoblennius gentilis (M)
S. Calif.
78
38. H. jenkinsi (?) (M)
82
(14) Family: Anabantidae
39 . Macropodus opercularis (F)
Paradise fish
S. China
8, 14, 15, 43, 44,
(= M. viridiauratus)
(15) Family: Eleotridae
40. Dormitator maculatus (F)
Sleeper
Mexico
48, 96. Not 90.
31 (N.Y.A. )H
(16) Family: Hexagrammoidae
41. Ophiodon elongatus (M)
Blue Cod
British Col.
54
IV. Order: Pleuronectiformes
(17) Family: Pleuronectidae
42. Pleuronectes flesus (M)
European Flounder
Irish, North,
2-5, 8, 10. 13, 14,
43. PI. platessa (M)
Plaice
Baltic, Barents
Arctic Seas
English Chan.
19-22, 25, 27-29,
36, 39, 42, 45,47,
63-67,74,83,84,
86, 88,95
2, 8, 14, 20, 21,
44. PI. (= Limanda) limanda (M)
Dab
& North Sea
25, 27, 36, 47-49,
63,95
2, 8
45 . Hippoglossoides platessoides (M)
American Plaice
N. Atlantic,
53
(18) Family: Soleidae
46 . Solea vulgaris (M)
Common Sole
Newfoundland
North Sea
2. 8, 14, 20
V. Order: Tetraodontiformes
(19) Family: Monacanthidae
47. Ceratacanthus {— Aleutera)
Orange Filefish
Atlantic Coast
30, 35, 70 (N.Y.A.)
schoepfii (M)
(20) Family: Ostraciidae
48. Lactophrys tricornis (M)
West Indian Cowfish
Florida and
31, 33 (N.Y.A. )i2
49. L. cornutus (M)
East Indian Cowfish
Bahamas
Indian Ocean
31 (N.Y.A.)
1From Drs. Roland Smith (N.J. State Conservation
Dep’t), A. Perlmutter (N.Y. State Conservation Dep’t,
Marine Division, and N.Y.U.), D. Merriman (Bingham
Oceanogr. Lab., Yale Univ.).
2From Dr. B. Levine (Tom’s River, N.J.).
3From Dr. Allison (Univ. Alabama).
4From Dr. C. P. Helmbolt (Univ. Conn.).
5From Dr. D. Flansen (111. Nat. Hist. Survey, Univ.
111.).
GFrom Dr. Roland Smith.
'From Dr. Richard Weissenberg (Phila., Penn.).
sFrom Drs. R. V. Bangham (Coll, of Wooster) and
Louis A. Krumholz (Univ. Louisville).
9From Dr. Wm. Braker (Shedd Aquarium, Chicago).
10From Mr. E. Weiss (tropical fish dealer, Brooklyn,
N.Y.).
“From Dr. Myron Gordon (deceased) (Genetics
Lab., N.Y. Aquarium).
12From C. M. Breder, Jr. (former director, N.Y.
Aquarium).
addition, these fish are often simultaneously
affected with a neoplastic disease (fibro-sar-
coma) (55-57) (Fig. 6) . Attention is also called
to the high incidence (20-30%) of multiple
tumors in pike perch in certain lakes of the
USSR during the summer months, for which a
virus is suspected as the cause (38) .
Lymphocystis disease is quite common in the
orange filefish (35, 70) during their summer'
residency along the north Atlantic Coast, and
in striped bass (33) off the coast of New Jersey,
New York and Connecticut, particularly in the
spring and early summer. The disease in the
white crappie and pike perch also shows a sea-
sonal distribution, with the highest incidences
occurring during the spring spawning runs (17,
46,91)."
Table 2 lists the host species in the New York
1965]
Nigrelli & Ruggieri: Studies on Virus Diseases of Fishes
87
Table 2. Experimentally-induced Lymphocystis Disease in Fishes
in the New York Aquarium Collection
No. Fish In
Species
Common Name
Which Disease
WasTransmitted
Remarks
Order: Perciformes
(1): Family: Centrarchidae
1 . Lepomis macrochirus
Bluegill Sunfish
6
Spontaneous disease found in 1
fish in Bronx Zoo pond; 1 auto-
and 5 homotransplant; positive
takes in 10 days at 22° C; June,
1956.
(2) Family: Chaetodontidae
2. Forcipiger longirostris
Forceps Fish
1
Disease found in 3 fish; 1 posi-
tive autotransplant in 8 days at
25° C; Jan., 1965.
(3) Family: Cichlidae
3. Aequidens portalegrensis
Port or Black Acara
3
Disease found in 4 fish; 1 fish
used as donor. Serially trans-
planted for 3 passages; 4th
passage negative; disease de-
veloped in 10 days at 25 °C.
Infected fish designated port
no. 1, 2 & 3; Jan., 1952.
4. Aequidens pulcher
Blue Acara
3
Port No. 1 used as donor; 2
positive and 1 negative; 12 days
at 25° C.
5. Hemichromis bimaculatus
Fire-mouth1
1
Port No. 1 donor; 1 positive
and 3 negative; homotransplant
negative; 10 days at 25° C.2
6. Tilapia macrocepliala
Black-chinned
Mouth-breeder1
1
Port No. 1 donor; 3 positive;
homotransplant negative; 12
days at 25° C.2
7. Tilapia ovale
Oval Tilapia1
1
Port No. 1 donor; 1 positive;
homotransplant negative; 11
days at 25° C.2
8. Tilapia sparmanii
Sparman’s Tilapia1
2
Port No. 1 donor; 2 positive, 1
negative; 13 days at 25° C.
1Disease not previously described for these species.
2Fish donated by Dr. L. Aronson, American Mus. Nat. History.
Aquarium’s collection in which lymphocystis
disease was experimentally induced. Except for
Aequidens portalegrensis and A. pulcher, the
cichlids listed have not been reported as actual
or potential hosts for this disease. The transmis-
sion experiments were made simply by implant-
ing fragments of lymphocystis tissue into the
pockets from which the scales were removed, or
by intradermal injection of emulsified material
on one side of the same host (Fig. 9) or in
another fish of the same (Fig. 8) or different
species. Lesions typical of lymphocystis disease
usually appear in 10 to 12 days at approximately
22-25° C, temperatures at which these fish are
kept in the New York Aquarium. The incubation
period and the rate of development of the dis-
ease is temperature-dependent (44, 93, 94). In
certain species, the disease may persist for five
to six months (44) , or longer, and we have seen
lymphocystis cells appear and disappear within
a few days. Lymphocystis disease can be serially
transplanted for a limited number of passages
(44, 94), and apparently there is a certain de-
gree of host resistance (35, 79, 93, 94), either
natural or acquired, as indicated by some of the
experiments shown in Table II.
Summary
Forty-nine species of fishes, 20 families from
5 orders, with spontaneous lymphocystis disease
(viral induced cellular hypertrophy or cellular
gigantism) are reported. Twenty-six of these dis-
eased species, in 11 families and 2 orders, were
88
Zoologica: New York Zoological Society
[50: 9
found in the New York Aquarium’s collection.
New host records are: Morone americana (white
perch) from Tom’s River, New Jersey, Lepomis
pallidus from Connecticut, Angelichthys ciliaris
(queen angelfish) from Florida, Forcipiger long-
irostris (forceps fish) from Hawaii, Aequidens
pulcher (blue acara) from Trinidad and Scato-
phagus argus (scat) from the Indo-Pacific. A
second case in Symphysodon discus (discus or
pompador fish) from the Amazon Basin is also
reported.
Experimental transmission of the disease is
recorded for the following cichlids in which the
disease has not been previously reported: Hemi-
chromis bimaculatus (fire-mouth), Tilapia mac-
rocephala (black-chinned mouth-breeder), Til-
apia ovale (oval Tilapia) , and Tilapia sparmanii
(Sparman’s Tilapia).
Lymphocystis disease is briefly described and
an annotated bibliography (1874-1965) is in-
cluded.
Annotated Bibliography
1. Alexandrowicz, J. S.
1951. Lymphocystis Tumours in the Red Mul-
let (Mullus surmuletus L.). J. Mar. Biol.
Assoc., U.K., 30: 315-332.
Excellent histological description of the lymph-
ocystis cells; speculations on the events leading
to release of infective virus.
2. Amlacher, Erwin
1961. Taschenbuch der Fischkrankheiten.
Gustav Fischer, Jena., 286 pp.
Brief description of the disease. Species listed
are: flounder, plaice, sole, dab, ruff, red mullet,
smelt, angelfish and hogfish.
3. Awerinzew, S.
1907. Zur Kenntnis von Lymphocystis john-
stonei Woodcock. Zool. Anz., 31: 881-
884.
Henneguya johnstonei is a new name for Lym-
phocystis johnstonei.
4. 1909. Studien fiber parasitische Protozoen. II.
Lymphocystis johnstonei Woodc. und
ihr Kernapparat. Arch. f. Protist., 14:
335-362.
Disease in Pleuronectes flesus from Barents
Sea. The enlarged cells were described as proto-
zoans.
5. 1911. Studien liber parasitische Protozoen. V.
Einige neue Befunde aus der Entwick-
lungsgeschichte von Lymphocystis john-
stonei Woodc. Arch. f. Protist., 22: 179-
196.
11% of flounders (Pleuronectes flesus ) from the
Murmansk Coast (Arctic Sea) affected annu-
ally; intracellular structures reported as stages
in the development of a myxosporidian spore.
6. Bangham, Ralph V.
1946. Parasites of Northern Wisconsin Fish.
Trans. Wise. Acad. Sci., Arts and Lett.,
36 (1944): 291-325.
Lymphocystis in walleye pike from Wisconsin
Lakes.
7. Bangham, Ralph V., & G. W. Hunter, III
1939. Studies on Fish Parasites of Lake Erie.
Distribution Studies. Zoologica, 24:
383-448.
Lymphocystis disease in the following: 7 wall-
eye pike ( Stizostedion vitreum), 1 blue pike
(Stizostedion glaucum ) and 1 sauger ( Stizoste-
dion canadensis griseus); lesions mainly on fins.
Lymphocystis cells in walleyes also found in
wall of digestive tract and heart.
8. Bergman, Arvid M.
1922. Fiskarnas Sjukdomar. Albert Bonniers
Forlag, 73 pp.
Lymphocystis disease in flounders from Swed-
ish and Danish waters; excellent photographs
of the lesions and a drawing of “mature” lym-
phocystis cell from the ruff. Disease is found
annually in 5% of the ruff and in 6-1 1% of the
flounder from the Baltic Sea. Other species re-
ferred to are: plaice ( Pleuronectes platessa),
dab ( Pleuronectes limanda), sole (Solea vul-
garis), paradisefish ( Macropodus viridiauratus)
and the sargo (Sargus annularis).
9. Benisch, J.
1937. Liber das Auftreten der Lymphocystis-
Krankheit bei einigen Korallenfischar-
ten. Wochenschr. f. Aq. und Terrarien-
kunde, 34: 380-382.
First report of lymphocystis in the coral fishes
(Premnas biaculeatus and Amphiprion percula);
photographs included.
10. Claussen, K.
1917. Ober Knotchenformigen Hautauschlag
bei Flundern. Zeitschr. f. Fleisch. -u-
Milchhyg, 27: 241.
Lymphocystis in Pleuronectes flesus from the
North Sea; agrees with Weissenberg as to the
nature of the cells.
11. Cowdry, E. V.
1955. Cancer Cells. W. B. Saunders Co., Phil-
adelphia, 677 pp.
Discusses lymphocystis cells in relation to cellu-
lar gigantism in cancer generally and the role
of viruses in certain neoplastic diseases.
12. Davis, H. S.
1953. Culture and Diseases of Game Fishes.
Univ. of California Press, 332 pp.
Brief description of the disease and notes its
absence in salmonids.
13. Doflein, F.
1928. Lehrbuch der Protozoenkunde. II. Teil.
Verlag von G. Fischer, Jena, pp. 439-
1262.
On page 1136, discusses Lymphocystis john-
1965]
Nigrelli & Ruggieri: Studies on Virus Diseases of Fishes
89
stonei under the subclass Haplosporidia but
recognizes the interpretation given by Weissen-
berg and Joseph on the nature of the disease
cell, especially that the cytoplasmic network is
a reaction product, the result of an intracellular
infection with a chlamydozoan.
14. Duijn, C. Van, Jr.
1956. Diseases of Fishes. Water Life, Dorset
House, London, 174 pp.
Host list for lymphocystis disease: paradisefish
( Macropodus), smelt ( Osmerus eperlanus), floun-
der (Pleuronectes fiesus), plaice (Pleuronectes
platessa ), sole (Solea vulgaris) and Sargus.
15. Dyk, Vaclav
1954. Nemoci Nasich Ryb. Nakladatelstvi
Ceskoslovenske Akademie Ved, Praha,
391 pp.
Reports briefly on the disease generally and
specifically on Rasin’s experiments on the trans-
mission of the disease in the paradisefish.
16. Fischthal, J. H.
1 947. Parasites of Northwest Wisconsin Fishes.
Trans. Wise., Acad. Sci., Arts & Lett.,
37: 157-220.
Disease in walleye pikes in Upper Turtle and
Teal Lakes, Wisconsin.
17. Hansen, Donald
1951. Biology of the White Crappie in Illinois.
Bull. 111. Nat. Hist. Sur„ 25: 211-265.
Disease on the fins of black and white crappies,
Pomoxis nigromaculatus and Pomoxis annu-
laris, from bottom land lakes in the Illinois
River Valley. Incidence of the disease in the
white crappie: 1.4% (Senachwine Lake, April,
1942), 9.5% (Lake dePue, April 25-27, 1942),
19.5% (Lake Chautauqua, Sept. 17-18, 1943).
18. Hyde, R. R.
1937. Laboratory Outline on Filterable Vi-
ruses. Macmillan Co., 85 pp.
A comparative virologist who accepted the viral
concept for lymphocystis disease. Discusses the
disease in walleye pikes from Lake Erie.
19. Jirovec, Otto
1932. Ergebnisse der Nuclealfarbung an den
Sporen der Microsporidian nebst einigen
Bemerkungen iiber Lymphocystis.
Arch. f. Protist., 77: 379-390.
First to report positive Feulgen reaction for the
cytoplasmic network in the lymphocystis cell
from the European flounder, Pleuronectes
fiesus.
20. Johnstone, J.
1905. Internal Parasites and Disease Condi-
tions of Fishes. Proc. & Trans. Liver-
pool Biol. Soc., 19: 278-300.
Accepted Woodcock’s interpretation that the
lymphocystis cells in flounders and soles were
sparozoans. Photograph of disease included.
21. 1907. Internal Parasites and Disease Condi-
tions of Fishes. Proc. & Trans. Liverpool
Biol. Soc., 21: 270-303.
Similar report.
22. 1926. Report on the Investigations Carried
Out During 1925 at the Sea Fisheries
Laboratory at the University of Liver-
pool. Proc. and Trans. Liverpool Biol.
Soc., 40: 59-71.
Further report on lymphocystis disease in floun-
ders; accepts Weissenberg’s interpretation of
the disease.
23. Joseph, H.
1917. Ober Lymphocystis einen fraglichen
Protozoischen Parasiten. Verh. d. K. K.
Zool. -Bot. Ges. in Wien. Ber. de Zool.
Sektion, p. 64.
First report of the disease in Sargus annularis
from Adriatic Sea. Questions the protozoan na-
ture of lymphocystis cell.
24. 1918. Untersuchungen iiber Lymphocystis
Woodc. Arch. f. Protist., 38: 155-249.
Further discussion of the disease in Sargus an-
nularis; independently concluded that the en-
larged cells were hypertrophied fibroblasts of
the fish. First detailed histological description
of the disease.
25. Lowe, John
1874. Fauna and Flora of Norfolk. Part IV.
Trans. Norfolk and Norwich Nat. Soc.,
Fishes, pp. 21-56.
First to report lymphocystis in English floun-
ders (Pleuronectes fiesus and Pleuronectes pla-
tessa).
26. Mavor, J. W., & S. M. Feinberg
1918. Lymphocystis vitrei, a New Protozoan
from the Pike-Perch, Stizostedion vit-
reum Mitchill. Trans. Wise. Acad. Sci.,
Arts and Lett., 19: 559-561.
First report of lymphocystis disease in the New
World, but the cells were interpreted as proto-
zoan parasites.
27. McIntosh, W. C.
1885. Diseases of Fishes. 1. Multiple Tumours
in Plaice and Common Flounder. 3rd
Ann. Rept. Scot. Fish. Bd. for 1884., p.
66-67.
The lesions were later recognized as lympho-
cystis tumors.
28. 1886. Further Remarks on the Multiple Tu-
mours of Common Flounder. 4th Ann.
Rept., Scot. Fish. Bd. for 1885, p. 214-
215.
Additional report on multiple tumors, includ-
ing the lesions later reported as Lymphocystis
johnstonei by Woodcock.
29. Minchin, E. A.
1912. An Introduction to the Study of Proto-
zoa, with Special Reference to the Para-
sitic Forms. Ed. Arnold Publ., London,
517 pp.
First to doubt the protozoan nature of Lympho-
cystis johnstonei Woodcock from flounders.
30. Nigrelli, Ross F.
1940. Mortality Statistics for Specimens in the
New York Aquarium, 1939. Zoologica,
25: 525-552.
90
Zoologica: New York Zoological Society
[50: 9
Lymphocystis in 1 clownfish (Amphiprion per-
cula), 2 blue angelfish (Angeliclithys isabelita)
and 1 orange filefish (Ceratacanthus schoepfii).
31. 1943. Causes of Disease and Death of Fishes
in Captivity. Zoologica, 28: 203-216.
Lymphocystis found in 1940 in the following
species: 1 banded butterfly fish (Chaetodon stri-
atus), 2 black angelfish ( Pomacanthus arcua-
tus), 1 East Indian cowfish ( Ostracion cornutus),
1 West Indian cowfish (Lactophrys tricornis),
1 red-spotted sunfish (Lepomis humilis), 3
striped sleeper (Dormitator maculatus), 6 pike-
perch (Stizostedion vitreum).
32. 1950. Lymphocystis Disease and Ergasilid
Parasites in Fishes. J. Para., 36: 36.
Disease in black angelfish, striped bass (Roccus
lineatus), and pumpkinseed sunfish (Lepomis
gibbosus) in the New York Aquarium. The role
of copepod parasites briefly discussed.
33. 1952. Virus and Tumors in Fishes. Ann. N. Y.
Acad. Sci., 54: 1076-1092.
Photographs of lymphocystis disease in West
Indian cowfish, pike-perch and in cichlid (Ae-
quidens portalegrensis). Successful transmission
from diseased cichlid to healthy fish of the same
species by direct implantation.
34. 1954. Tumors and Other Atypical Cell
Growths in Temperate Freshwater Fish-
es of North America. Trans. Amer.
Micro. Soc., 83: 262-295.
North American host list and a brief descrip-
tion of the disease.
35. Nigrelli, R. F., & G. M. Smith
1939. Studies on Lymphocystis Disease in the
Orange Filefish Ceratacanthus schoepfii
(Walbaum), from Sandy Flook Bay,
N.J. Zoologica, 24: 255-264.
A review of the literature, together with a de-
tailed macroscopic and microscopic description
of the disease in the filefish, a summer resident
in the New York Bight. Lymphocystis cells
found in fins, ovary, spleen and wall of the
gastro-intestinal tract; stages in healing process
described. Attempts to transmit the disease to
killifish were negative.
36. Nordenberg, Carl-Bertel
1962. Das Vonkommen der Lymphocystis-
krankheit bei Scholle und Flunder im
Oresund. Kungl. Fysiogr. Sallskijets i
Lund Forhandl., 32: 17-26.
Incidence of disease in flounders: April-May
7%; July-Sept. 10-12%; Oct. -Dec. 3-4%; lan.-
March 7-8%.
37. Olsen, Donald E.
1958. Statistics of a Walleye Sport Fishery in
a Minnesota Lake. Trans. Amer. Fish.
Soc., 87: 52-72.
Fish that were marked by removing scales or
by clipping fins were more susceptible to the
disease.
38. Petrushevskii, G. K.
1957. Parasites and Diseases of Fish. Bull. All-
Union Sci. Res. Inst. Fresh-water Fish-
eries (USSR), 42: 1-338. (1961 Trans-
lation publ. for NSF and U.S. Dept.
Int. by the Israel Program for Scientific
Translation).
Multiple tumors in 20-30% of the pike-perch
in White Lake (USSR) during the summer
suspected to be viral in origin; the tumors may
be lymphocystis.
39. Plehn, M.
1924. Praktikum der Fischkrankheiten. E.
Schweizerbart’sche, Stuttgart, 179 pp.
Brief description of the disease in European
fishes.
40. Porter, Annie
1952. Report of the Honorary Parasitologist
for the year 1951. Proc. Zoological So-
ciety of London, 122: 535-536.
Lymphocystis in the disc cichlid (Symphysodon
discus).
41. 1953. Report of the Honorary Parasitologist
for the year 1952. Proc. Zoological So-
ciety of London, 123: 253-257.
The disease in five striped sea perch (Serranus
atricauda).
42. Raabe, H.
1935. Un Microsporidium dans des Lympho-
cystis chez les plies. Bull, de l’Institut
Oceanographique (Monaco), No. 665:
1-10.
Disease in flounders (Pleuronectes flesus) from
the Baltic near the Marine Station at Hel (Po-
land) in the Bay of Dantzig. High incidence of
lymphocystis found annually in the spring. The
development of the gigantic cell, characteristic
of lymphocystis, believed to be caused by an
intracellular microsporidium.
43. Rasin, K.
1927. Prispevek k pathogenesi Lymphocystis
johnstonei Woodcock. I. Biol. Spisy
Vysoke Skoly Zverolekarske Brno.
(Publ. Biol. Ecole Vet.), 6: 11-38. (Biol.
Abstract no. 24008, 1931).
First detailed experimental studies on transmis-
sion of lymphocystis disease in paradisefish,
Macropodus. Infection induced by implanta-
tion, by injection of saline suspension of emul-
sified diseased tissue, by smearing injured skin
with emulsion and by exposing injured (scaled)
fish to emulsified material introduced to tank
water; lymphocystis tissue 47 to 105 days old
infective, even 105-day-old material dried over
KOH at 18-20° C, but with diminished viru-
lency after 67 days of drying. Lymphocystis dis-
ease in Macropodus disappears in 5-7 months.
44. 1928. II. idem., ibid, 7: 1-14. (Biol. Abstract
No. 20631, 1931).
Virus (emulsion) causing lymphocystis disease
in Macropodus carried through 17 passages.
Lymphocystis material from fish dead for 24
hrs. produced disease in healthy fish in 9 days;
material obtained from fish allowed to putrefy
for 5 days in tank water at 18-20° C retained
1965]
Nigrelli & Ruggieri: Studies on Vims Diseases of Fishes
91
its infectivity; severity of disease related to di-
lution and to length of exposure time; 1: 1 mil-
lion dilution of suspension of emulsified ma-
terial infective. Rate of growth of lymphocystis
cells in experimental fish related to tempera-
ture; cells double in size in 12 days at 30° C
compared to growth of cells in fish in 24 days
at 18° C; fish kept at 16° C more resistant to
experimental infection; susceptibility of fish to
lymphocystis is increased by direct application
of virus (emulsion) to damaged skin. Inability
to demonstrate filterability of virus believed
to be due to absorption of virus on tissue frag-
ments which were removed by the filter paper.
Giant gourami (Trichogaster fasciatus= Colisa
fasciata) experimentally infected with lympho-
cystis from paradisefish (Macropodus); this rep-
resents first inter-generic transmission.
45. Reichenbach-Klinke, H.-H.
1957. Krankheiten der Aquarienfische. Alfred
Kernen Verlag, Stuttgart, 215 pp.
Short discussion of lymphocystis disease.
46. Ryder, R. A.
1961. Lymphocystis as a Mortality Factor in
a Walleye Population. The Progressive
Fish-Culturist, 23: 183-186.
Walleye population from Nipigon River, On-
tario. In 1956, 1,000 fish were tagged, 248
(24.8%) of which were diseased; 55 (22.2%) of
the diseased fish were recaptured. In 1957, 504
fish were tagged, 147 (29.2%) of which were
infected, and 52 (35.4% ) of these were recap-
tured. Incidence of the disease increased during
the spawning period from 17.5% at the start
of the tagging to 30.5% at its termination 10
days later; lymphocystis at its highest level dur-
ing and immediately after spawning; tagged
infected fish showed no trace of the disease in
summer, fall or winter. No appreciable effect
on mortality rates; diseased fish more suscepti-
ble to capture by gill nets.
47. Sandeman, G.
1893. On the Multiple Tumours in Plaice and
Flounders. 11th Ann. Rept. Scot. Fish.
Bd. for 1892, 391-392.
Most of the multiple tumors in these fish were
lymphocystis.
48. SCHAPERCLAUS, W.
1935. Fischkrankheiten. G. Wenzel u. Sohn,
Braunschweig, 72 pp.
Excellent photographs of the lesions on fins of
a plaice and on a female paradisefish.
49. 1954. Fischkrankheiten. Akademie-Verlag,
Berlin, 708 pp.
Photographs of lymphocystis cells of the plaice,
and the lesions in situ in the clownfish, Premnas
biaculeatus, reported by Benisch (1937).
50. SCHLUMBERGER, HANS G.
1958. Krankheiten der Fische, Amphibien und
Reptilien. In: Vol. II. Pathologie der
Laboratoriumstiere. Springer- Verlag,
Berlin.
Excellent macroscopic and microscopic photo-
graphs of lymphocystis in the long-ear sunfish,
Lepomis megalotis.
51. Smith, Kenneth
1940. The Virus. Macmillian Co., N. Y., 176
pp.
Lists lymphocystis among the known viral dis-
eases of plants and animals.
Smith, G. M., & R. F. Nigrelli
1937. Lymphocystis Disease in Angelichthys.
Zoologica, 22: 293-295.
First report of lymphocystis disease in a marine
fish (Angelichthys isabelita) of the North Amer-
ican Atlantic coast.
53. Templeman, Wilfred
1965. Lymphocystis Disease in American
Plaice of the Eastern Grand Bank. lour.
Fisheries Res. Board of Canada, in
press.
First description of lymphocystis disease in
North American flat fishes ( Hippoglossoides
platessoides); 1% of the fishes found to be in-
fected.
54. Walker, Roland
1947. Lymphocystis Disease and Neoplasia in
Fish. Anat. Rec., 99: 559-560. (abstract).
First report of lymphocystis in a Pacific Coast
fish, Ophiodon elongatus, from the Straits of
Georgia, B.C.,; also in 5 yellow perch, Perea
fiavescens, from Lake Erie and in walleye pike
from Lake Oneida, in which lymphocystis is as-
sociated with sarcomatous tumors.
55. 1957. Warty Walleyes. The N. Y. State Con-
servationist, 12: 28-29.
Lymphocystis and sarcoma in walleyes from
Lake Oneida, New York.
56. 1958. Lymphocystis Warts and Skin Tumors
of Walleye Pike. Rensselaer Review of
Graduate Studies, No. 14: 1-5.
The incidence of the disease in walleye pike
from Lake Oneida ranges from less than 1%
to 5%.
57. 1961. Fine Structure of a Virus Tumor of Fish.
American Zoologist, 1: (Abstract No.
71).
The virus of the sarcoma in walleye pike found
to be different from the lymphocystis virus.
58. 1962. Fine Structure of Lymphocystis Virus
of Fish. Virology, 18: 503-505.
First detailed electronmicroscopic report of the
lymphocystis virus. The viral particles of the
lymphocystis cells from the pike perch mea-
sure 200 millimicrons and show polyhedral
capsids surrounded by nucleoids.
59. 1965. Viral DNA and Cytoplasmic RNA in
Lymphocystis Cells of Fish. In: Viral
Diseases of Poikilothermic Vertebrates.
Annals N. Y. Acad. Sci., 126: 375-385.
Distribution of viral DNA and cytoplasmic
RNA in lymphocystis cells from walleye pike
92
Zoologica: New York Zoological Society
[50: 9
and sunfish (Lepomis) as revealed by U.-V.
Fluorescence Microscopy after staining with
acridine orange.
60. Walker, Roland, & R. Weissenberg
1965. Conformity of Light- and Electron- Mi-
croscopic Studies on Virus Particle Dis-
tribution in Lymphocystis Cells of Fish-
es. Ibid., 126: 386-395.
The viral particles in lymphocystis cells from
diseased walleye pike, bluegill sunfish, Euro-
pean flounder and the cichlid fish ( Cichlasoma )
are compared.
61. Walker, Roland, & Ken Wolf
1962. Virus Array in Lymphocystis Cells of
Sunfish. American Zoologist, 2: 566
(Abstract).
Electron microscopic studies of lymphocystis
cells in bluegill sunfish following subcutaneous
inoculation with cell-free filtrate of homoge-
nized diseased tissue from Micropterus. The
virus particles are similar to those seen in wall-
eye pike.
62. Watson, Stanley W.
1954. Virus Diseases of Fish. Trans. Amer.
Fish. Soc., 83: 331-341.
A brief review of the fish species susceptible to
lymphocystis disease. Lesions persist from 1 to
3 years; diseased walleyes from Saginaw Bay
weighed less (5.5 to 6.5%) than “healthy” fish
of the same length.
63. Weissenberg, R.
1914. Uber infetiose Zellhypertrophie bei
Fischen (Lymphocystiserkrankung) .
Sitz.-Ber. Klg. preuss. Akad. Wiss., 30:
792-804.
First to recognize the infectious nature of dis-
ease in European flounder, plaice and ruff; that
the disease is caused by a virus; that the en-
larged elements are hypertrophied host con-
nective tissue cells; that the inclusions are viral
reaction products.
64. 1920. Lymphocystisstudien. (Infektiose Hy-
pertrophie von Stutzgewebszellen bei
Fischen). I. Die reifen Geschwulste bei
Kaulbarsch und Flunder. Lymphocystis-
genese beim Kaulbarsch. Arch. mikr.
Anat., 94: 55-134.
Detail description of the development of the
lymphocystis tumor in the ruff, Acerina cernua,
and flounder, Pleuronectes flesus, from the
Baltic.
65. 1921a. Lymphocystisstudien. II. Abgrezung
Netzkorpers der Lymphocystiszellen
gegen das Golginetz (Joseph’s centro-
phormium). Sitzunsber. Gesellsch. Na-
turforsch. Fruende Berlin, 1920 (vor-
getragen in der Sitzung, vol. 15, Juni).
Discussion on the cytoplasmic network in the
lymphocystis cell in relation to Joseph’s inter-
pretation that the network is a centrophormium
or golgi-net.
66. 1921b. Neue Lymphocystisbeobachtungen. Sit-
zungsber. Berlin Mikrobiol. Gesselsch.
(Kurze mitteilung in der Sitzung vom
7 Juni, 1920). Berlin Klin. Wochenschr.,
nr. 2: 35.
Additional studies on lymphocystis disease in
European fishes and reiteration of the viral
etiology.
67. 1921c. Lymphocystiskrankheit der Fische. In:
S. v. Prowazek und W. Noller, Hand-
buch der Pathogenen Protozoen. 3:
1344-1380.
Review of lymphocystis disease in European
fishes.
68. 1929. Neue Gesichtspunkte in der vergleich-
enden Tumorforschung. Zeitschr. f. arz-
tliche Fortbildung, No. 17: 555-559.
Comparison of the cell hypertrophy due to virus
as in lymphocystis disease of the flounder and
ruff and that caused by intracellular micro-
sporidians in ganglion cells of the angler fish
( Lophius piscatorius), and certain connective
tissue cells of European sticklebacks.
69. 1937. Intracellular Parasitism in Fish Produc-
ing a Gigantic Growth of the Infected
Cells. Anat. Rec., 70: 68. (Abstract).
Further comparison of lymphocystis virus and
microsporidian parasites producing cellular gi-
gantism of the host cells.
70. 1938. Studies on Virus Diseases of Fish. I.
Lymphocystis Disease of the Orange
filefish (Aleutera schoepfii). Amer. J.
Hyg., 28: 455-462.
Description of disease in a filefish in the Phila-
delphia Aquarium. Line drawings showing the
development of the characteristic cytoplasmic
inclusions.
71. 1939a. Studies on Virus Diseases of Fish. II.
Lymphocystis Disease of Fundulus het-
eroclitus. Biol. Bull., 76: 251-255.
Description of the disease in the killifish. At-
tempt at infecting Fundulus heteroclitus and
F. diaphanus with walleye pike lymphocystis
material were negative; concluded that there
is a certain degree of host specificity.
72. 1939b. Studies on Virus Diseases of Fish. 111.
Morphological and Experimental Ob-
servations on the Lymphocystis Disease
of the Pike-Perch, Stizostedion vitreum.
Zoologica, 24: 245-254.
Sixty diseased pike-perch collected from Lake
Huron and Lake Erie. Detailed description of
the disease in this species; transmission of the
disease to young pike-perch from Spirit Lake,
Iowa; 5% of pike-perch from Saginaw Bay,
Lake Huron, were infected in Spring of 1937.
73. 1945. Studies on Virus Diseases of Fish. IV.
Lymphocystis Disease in Centrarchidae.
Zoologica, 30: 169-184.
Lymphocystis reported in following species: 18
Lepomis gibbosus, 21 L. macrochirus, 1 hybrid
1965]
Nigrelli & Ruggieri: Studies on Virus Diseases of Fishes
93
L. cyanellus X L. macrochirus, 1 L. megalotis,
2 Pomoxis nigromaculatus, 3 Huro salmoides,
1 Micropterus pseudaplites. Also reports trans-
mission experiments in L. gibbosus and L. mac-
rochirus; disease appeared in 25 days after
spraying lymphocystis emulsion over the gills;
Lepomis not susceptible to lymphocystis from
pike-perch. Development of Guarnieri-like
body to perinuclear network described and
figured.
74. 1946. Observations on the Developmental Cy-
cle of the Lymphocystis Virus in Fish
(Pleuronectes flesus, Stizostedion vit-
reum, Acerina cernua). Anat. Rec., 94:
89. (Abstract).
Concludes that lymphocystis is caused by a
macrovirus associated with plaques, somewhat
like the elementary bodies in viral diseases of
higher vertebrates.
75. 1949. Studies on Lymphocystis Tumor Cells
of Fish. I. The Osmiophilic Granules of
the Cytoplasmic Inclusions and Their
Interpretation as Elementary Bodies of
the Lymphocystis Virus. Cancer Re-
search, (9): 537-542.
The osmiophilic granules on the outer layers
of the lymphocystis inclusion bodies correspond
to the elementary bodies of other macrovirus
and are considered to be infective stages of the
lymphocystis virus.
76. 1951a. Studies on Lymphocystis Tumor Cells
of Fish. II. Granular Structures of the
Inclusion Substance as Stages of the
Developmental Cycle of the Lympho-
cystis Virus. Cancer Research, 1 1 : 608-
613.
Evidence suggests that non-osmiophilic gran-
ules of the inclusion substance multiply by fis-
sion and eventually form osmiophilic granules;
the former are considered the vegetative stages
which serve as growth for the virus within the
host cells and the osmiophilic granules are the
infective virus particles. The osmiophilic gran-
ules, which accumulate in large numbers as the
cells increase in size, are liberated by disinte-
gration of the tumor cells after they are ex-
truded into the water, or after death of the fish.
77. 1951b. Some Results of Morphological Studies
on the Developmental Cycle of the Lym-
phocystis Virus of Fish with Reference
to the Experimental Work of K. Rasin.
Anat. Rec., Ill: (Abstract no. 187).
The bursting of lymphocystis cells in situ pro-
duces infection of neighboring fibroblasts or
phagocytes.
78. 1951c. Four Additions to the List of Host Fish
in Which Lymphocystis Tumors have
been Observed as the Result of Spon-
taneous Viral Infection. Anat. Rec.,
Ill: (Abstract no. 289).
Spontaneous lymphocystis found in 1 black
angelfish Pomacanthus arcuatus, 1 French
angelfish Pomacanthus paru, 1 Hypsoblennius
gentilis, and 2 Cichlasoma synspilum.
79. 195 Id. Experimental Lymphocystis Infection of
the Killifish Fundulus heteroclitus with
Emulsion of Lymphocystis Tumors of
the Perch Stizostedion vitreum. Anat.
Rec., Ill: (Abstract no. 290).
Contrary to his 1939 (a) studies, positive in-
fection of killifish occurred when exposed to
tumor emulsion of Stizostedion; in 1944, 4
Fundulus of six fish treated became infected; in
1945, one out of 41 fish became infected; how-
ever, in both experiments, there was an early
cessation of growth of the tumor cells followed
by degeneration, indicating that the killifish is
not a suitable host for pike-perch lymphocystis
virus.
80. 195 le. Positive Result of a Filtration Experi-
ment Supporting the View that the
Agent of the Lymphocystis Disease of
Fish is a True Virus. Anat. Rec., Ill:
(Abstract no. 291).
First filtration experiment supporting viral
theory for lymphocystis. One Fundulus out of
31 specimens became infected when treated
with Stizostedion tumor material filtered
through Chamberland-Pasteur filter L5; one
Fundulus out of 41 fish treated with non-fil-
tered pike-perch material also became infected.
81. 1952. Parallel Features in the Parasitism and
Life Cycle of Fish Microsporidia and
Fish Viruses. Proc. Soc. Protozoologists,
3: (Abstract no. 5).
A new analysis of hypertrophy of tissue cells
induced by microsporidians and by lympho-
cystis virus.
82. 1955. The Third Spontaneous Case of Lym-
phocystis Virus Disease of Fish from
the Pacific Coast of North America.
Anat. Rec., 122: 434-435 (Abstract no.
38).
Disease in Hypsoblennius, probably H. jenkin-
si, from San Diego Bay, California.
83. 1956. Granular Components of the Basophilic
Lattice in the Lymphocystis Virus In-
clusion Bodies of Pleuronectes. Archiv
f. die Gesamte Virusforschung, 7: 1-17.
Studies on flounders Pleuronectes flesus with
spontaneously developed lesions from the Bal-
tic in the vicinity of Rugen Island and in ex-
perimentally infected fish kept in aquaria. A
basophilic lattice functions as a supporting
framework for the maturing lymphocystis in-
clusion bodies. The relationships of the baso-
philic granules to the lattice and the fate of the
lattice in advanced stages of the lymphocystis
cell are discussed in relation to the filamentous
virus resembling the influenza group.
84. 1960a. Some Remarkable Osmiophilic Struc-
tures of the Inclusion Bodies in the
Lymphocystis Virus Disease of the Eu-
ropean Flounder. Arch. f. die Gesamte
Virusforschung, 10: 253-263.
Diseased flounders from Morecambe Bay, Irish
Sea. Three types of osmiophilic structures are
demonstrated: granules, paired dumb-bell
94
Zoologica: New York Zoological Society
[50: 9
shaped rods (lying parallel or crossed) and
lattice. These represent developmental stages
of the lymphocystis virus. The elongated forms
are considered to be the infectious stage, since
they are found in great numbers in lympho-
cystis cell in an advanced stage of development.
85. 1960b. Paired Structures of the Inclusion Bodies
in the Lymphocystis Disease of Perches.
Bact. Proc. (Abstract no. M180).
Osmiophilic granules in the inclusion bodies of
the pike-perch appear as tetrads in relatively
young cells (250 microns). The tetrads con-
sist of two symmetrical dyads connected by a
delicate thread and sometimes by a denser fila-
ment, appearing as two rods with polar gran-
ules. Somewhat similar granules are found in
lymphocystis cells of Acerina cernua. It is sug-
gested that the virus of lymphocystis is fila-
mentous.
86. 1960c. Further Studies on the Lymphocystis
Disease of Fish. Anat. Rec., 137: 400.
(Abstract).
The filamentous-like rods with osmiophilic
granules at the tips are described and their
distribution in the lymphocystis cells in several
fish species indicated. In the tumors of the
European flounder and perches, the rods are
predominantly found within the cytoplasmic
inclusion bodies; in the Atlantic angelfishes,
they are found within the nucleus and as free
intracytoplasmic colonies; paired rods were
also found in leucocytes, apparently the result
of phagocytosis.
87. 1965. Fifty Years of Research on the Lym-
phocystis Virus Disease of Fishes (1914-
1964). In: Viral Diseases of Poikilo-
thermic Vertebrates. Annals N.Y. Acad-
emy of Science, 126: 362-374.
Review of Dr. Weissenberg’s research on lym-
phocystis disease from 1914, when he first pro-
posed the virus theory, to the present day.
88. 1965. Morphological Studies on the Lympho-
cystis Tumor Cells of a Cichlid from
Guatemala, Cichlasoma synspilum
Hubbs. ibid., 126: 396-413.
The young lymphocystis cell contains scattered
basophilic corpuscles in contrast to single Guar-
nieri-like body that produces the inclusions
seen in perches and flounder tumor cells. Vac-
uoles appear in the cytoplasm of young cell on
the walls of which small groups of osmiophilic
granules, filaments and sometimes paired rods
accumulate. Electronmicroscopic studies show
typical lymphocystis viral structures (poly-
hedral) in the cytoplasm.
89. Weissenberg, R., R. F. Nigrelli &
G. M. Smith
1937. Lymphocystis in the Hogfish, Lachno-
laimus maximus. Zoologica, 22: 303-
305.
Description of the lymphocystis cell, together
with an excellent drawing of a mature cell.
90. Wenyon, C. M.
1926. Protozoology. Vol. 1. William Wood &
Co., New York. 788 pp.
Pages 770-773 refer to Lymphocystis macro-
podis, a sarcocystis-like parasite in the intesti-
nal mucosa of the kangaroo (Macropits sp.);
not to be confused with lymphocystis disease in
the paradisefish, Macropodus.
91. Witt, A., Jr.
1957. Seasonal Variation in the Incidence of
Lymphocystis in the White Crappie from
the Niangua Arm of the Lake of the
Ozarks, Missouri. Trans. Amer. Fish.
Soc., 85: 271-279.
Total of 7,499 fish collected in 1950-1951 and
in 1952-1955. Seasonal variation in incidence
of the disease is as follows: July 10.7%, Oc-
tober 1.7%, November 6.9%, April 1.4%. The
lesions are found on tail fins in most (60% ) of
the diseased fish; 97% of the infected fish col-
lected in 1950-1951 were under 6.5 inches long
(3 yr.-old, or 1949 class). The disease is not
lethal but affected fish weighed 3-5% less than
healthy specimens of the same length. One wall-
eye in the collection was also infected, but no
other centrarchid.
92. Wolf, Ken
1958. Lymphocystis Disease of Fish. U. S.
Dept. Interior, Fish and Wildlife Serv-
ice, Fishery Leaflet No. 458, 4 pages.
A brief description of the disease for fishery
biologists, together with a selected annotated
bibliography.
93. 1962. Experimental Propagation of Lympho-
cystis Disease of Fishes. Virology, 18:
249-256.
Experimental transmission of the lymphocystis
virus from large-mouth bass to bluegill sunfish
and propagated in the latter species for two
years by implantation and by injection of fil-
tered (Millipore HA) fresh, aged (2 yrs. at
— 20°C) or desiccated material. The virus is
glycerol- and ether-sensitive.
94. Wolf, Ken, & C. P. Carlson
1965. Multiplication of Lymphocystis Virus in
the Bluegill Sunfish (Lepomis macro-
chirus). In: Viral Diseases of Poikilo-
thermic Vertebrates. Annals N. Y. Acad.
Sci., 126: 414-419.
Classical curve of multiplication at 25° C was
demonstrated for the lymphocystis virus in ex-
perimental infections in bluegill sunfish.
95. Woodcock, H. M.
1904. Notes on a Remarkable Parasite of
Plaice and Flounders. Trans. Liverpool
Biol. Soc., 18: 143-152.
First description of the lymphocystis cell, be
lieved to be a sporozoan parasite, for which
the name Lymphocystis johnstonei was pro-
posed.
1965]
Nigrelli & Ruggieri: Studies on Virus Diseases of Fishes
95
96. Zschiesche, A.
1910. Eizellen in der Haut von Macropoden.
Zool. Ans., 36: 294-298.
First to report the disease in the freshwater par-
adisefish, Macropodus, originally from China.
However, the enlarged cells were thought to be
eggs.
96
Zoologica: New York Zoological Society
[50: 9: 1965]
EXPLANATION OF THE PLATES
Plate I
1. Typical lymphocystis nodules in the dorsal fin
of the disc cichlid, Symphysodon discus. 4X-
2. Nodules on dorsal fin of West Indian cowfish,
Lactophrys tricornis. Note individual lympho-
cystis cells within the nodule and along several
of the fin rays. 4x.
3. Lymphocystis nodules in the anal fin of the
scat, Scatophagus argus. 2X-
4. Lymphocystis disease in the sleeper, Dormi-
tator maculatus. Slightly less than natural size.
Plate II
5. Lymphocystis lesions in the European perch
or ruff, Acerina cernua, one of the species in
which the disease was first described by Dr.
Weissenberg in 1914. Slightly larger than na-
tural size. Courtesy of Dr. R. Weissenberg.
6. Lymphocystis “tumors” in the pike-perch, Stiz-
ostedion vitreum, the species in which the dis-
ease was first reported in North America by
Mavor & Feinberg in 1918. About natural size.
Plate III
7. Typical fin lesions in the cichlid Aequidens
portalegrensis. This fish was the donor for the
transmission experiments reported in Table II
and shown in Fig. 8.
8. Aequidens portalegrensis showing typical skin
response to experimental infection. Natural
size.
Plate IV
9. Forcipiger longirostris (forceps fish), showing
characteristic tumor-like growth at the site in
which two crushed lymphocystis cells from the
right pectoral fin were introduced. Note the
cells on the left pectoral fin. About natural size.
10. Lymphocystis disease in white perch, Morone
aniericana. The hemorrhagic appearance is a
characteristic response in the early stages of the
disease. Note absence of nodules. About Vi
natural size.
11. A non-nodular response of lymphocystis dis-
ease in the striped bass, Roccus lineatus. The
individual hypertrophied connective tissue cells
are scattered just below the epidermis. 2X-
Plate V
12. An exceptional development of lymphocystis
cells on the dorsal surface of striped bass. The
granular lesions appear as extensive thickened,
yellowish patches. 3X.
13. Lymphocystis cells from the nodule in the cow-
fish shown in Fig. 2. Note the appearance of
the nucleus and the cytoplasmic inclusions and
compare with Figs. 15-24. Masson’s stain;
150X.
14. A typical lymphocystis cell in the gill of the
cowfish, showing the enlarged nucleolus, pe-
ripherally-scattered cytoplasmic inclusions and
thickened hyalin membrane. The tissue reaction
suggests that this cell developed in situ, and is
not a metastatic element. Masson’s stain; 350X-
Plate VI
15. Lymphocystis cells from forceps fish shown in
Fig. 9. Haematoxylin-eosin; 150X-
16. Another area of the growth in Fig. 15 showing
a binucleate cell, chromatin clumps within the
nucleus and basophilic cytoplasmic inclusions.
Note the gelatinous matrix. Haematoxylin-
eosin; 300X-
Plate VII
17. Two characteristic hypertrophied cells from the
lymphocystis disease in the forceps fish. The
bottom cell measures 75 X 95 microns; nucleus
36 X 35 microns; nucleolus about 12 microns.
Haematoxylin-eosin; 600 X.
18. Cell from forceps fish as seen in the interfer-
ence microscope. Note the plaques filled with
weakly-staining bodies. Haematoxylin-eosin;
800 X-
Plate VIII
19. Nuclear details of a single hypertrophied cell in
the forceps fish. Note the dissolution of the
nucleolus. Haematoxylin-eosin; 1350X-
20. Lymphocystis cells from white perch shown in
Fig. 10. There is some shrinkage from fixation.
In this species, as will be noted, the basophilic
inclusions form compact masses in the periph-
ery of the cell; the nucleus is highly vacuolated.
Masson’s stain; 300X-
21. Nuclear and cytoplasmic details in a single
white perch lymphocystis cell. Haematoxylin-
eosin; 1350X-
Plate IX
22. Inflammatory response associated with the lym-
phocystis disease in the white perch. Masson’s
stain; 300x.
23. A group of hypertrophied cells in experimen-
tally induced lymphocystis disease in Aequidens
portalegrensis shown in Fig. 8. The irregular
shape of the cells is not due to shrinkage. Note
that the capsular membrane is intact and fol-
lows the shape of the cell. Haematoxylin-eosin;
600 X.
24. Details in the nuclear area of a lymphocystis
cell from Aequidens. Note numerous granules
each surrounded bv_ a halo-like structure.
Haematoxylin-eosin; interference microscope;
2000 X.
Plate X
25. Lymphocystis cells in striped bass showing the
extensive and unusual development of hyalin
substance. Haematoxylin-eosin; 50x.
26. PAS-positive hyalin membrane surrounding
the individual lymphocystis cell in white perch.
This membrane or capsule is best seen in Fig.
14. 150x-
10
Vortices and Fish Schools
C. M. Breder, Jr.
The American Museum of Natural History
(Plates I-IV; Text-figures 1-3)
Introduction
The recent increase in research on the for-
mation and organization of fish schools,
especially that bearing on the ecology and
development of such assemblages, has produced
some distinctly useful information. See, for in-
stance, E. Shaw (1958a and b, 1961), Cahn &
Shaw (1963 and MS.), John (1964). None of
these investigators, however, has explored the
hydrodynamic aspects and consequences of the
effects of the passage of solid bodies such as
fishes through fluid media, although all are ap-
parently aware of the problem. The published
results of current researches in the fields of hy-
drodynamics, fluid mechanics and hydraulics
form a considerable literature, some of which is
distinctly pertinent to problems of fish locomo-
tion and social grouping, including such studies
as Rosen (1959), W. Shaw (1959), Birkholf
(1962), Rouse (1946 and 1963) and Gadd
( 1 963a and b ) . Rosen and Gadd cover the appli-
cation of modern fluid mechanics to studies on
fish locomotion, which is, of course, especially
germane to schooling problems.
Since swimming fishes envelop themselves in
a series of vortices and leave a dying trail of them
behind, it follows that these features of fluid
mechanics become a factor in the environment
of other fishes which approach or follow. The
broader aspects of the hydrodynamic details of
the environment within which fish schools oper-
ate are discussed herein. Other types of social
assemblages of fishes are not discussed in detail
at this time for reasons which will be indicated
later. The usage of “aggregations,” “school,”
“pods” and related terms follows that of Breder
(1959).
The phenomenon of continuing vortex forma-
tion by the relative motion between a mass of
fluid and a solid object immersed therein was
first discussed in detail by Karman (1912). These
series of vortices, which stream after such an
object, are usually referred to as Karman vortex
sheets, trails or streets. However, it has only been
in recent years that investigators have begun to
consider their possible importance to studies of
fish locomotion. Two possible approaches will be
considered. The first is that of the interaction
and consequences of the vortices cast off by each
fish. In this, the fishes’ reactions to other nat-
urally-occurring vortices are also examined. The
second is that in which an entire school of fishes
is itself considered a vortex when it forms a
closed figure. Such closed figures, usually almost
circular, rotate as a whole but have no forward
translation. The individual fishes face and circu-
late all clockwise or all counterclockwise. Such
groups are usually called fish mills.
Appreciation is acknowledged for assistance
from the following: to Miss Sara L. Page, a
Lincoln Ellsworth field assistant, for laboratory
and field assistance in the experimental work; to
Mrs. Mary G. Hume, Scientific Assistant of the
Department of Ichthyology, for laboratory and
office assistance; to the Goodyear Aircraft Cor-
poration for permission to use certain films for
study and the photographs in Plate I; to Mr.
George A. Bass for permission to use the photo-
graph in Plate II; and to Dr. James W. Atz, Dr.
Phyllis H. Cahn and Dr. Donn E. Rosen for
critically reading the manuscript and suggesting
valuable improvements.
Intrinsic Vortices
Since the appearance of the analysis of the
hydrodynamics of a swimming fish by Rosen
(1959), any study concerned with the approach
of one fish to another must necessarily include
attention to the possible effects of the locomotor
vortices produced by both. Rosen demonstrated,
by ingenious means, that vortices form alternate-
ly on each side of a swimming fish at the side of
the head which presents a concave aspect. These
97
98
Zoologica: New York Zoological Society
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appear to pass backwards, nested in the concave
areas of the fish’s undulations. This apparent
movement of the vortices is actually the forward
motion of the fish as it insinuates itself about the
successive vortices, which themselves remain
substantially stationary while the fish progresses
between them. See Text-figs. 1 and 2. With the
slight oscillation of the fish’s head these vortices
form alternately on one side and then the other.
As a consequence they are spaced just one-half
the frequency of the fish’s swimming cycle. These
alternating and oppositely rotating vortices align
themselves in a right and a left line so close to-
gether as to mark the track of the fish as a file
of contra-rotating vortices in a single wavy line.
This is brought about by a complex crossing over
from side to side of the vortices around the body
of the fish as it moves along, the details of which
do not concern the present purposes except to
note the following condition. The vortex ele-
ments which cross over, and may cross back
Text-fig. 1. Diagram of the relationships between
a school’s spacing and the regenerative vortex flow.
The center fish with the flow lines about it has been
traced from Figure 24 of Rosen (1959). The added
outer two dotted lines indicate the approximate
limit of vortex influence. The swirls indicated give
only a faint indication of the whole vortex system,
as these lines traced from a photograph show only
the marks made by their lower extremities because
of the manner in which these photographs were pro-
duced. Secondary vortices are not indicated. The
slightly wavy mid-line indicates the path of the
nose. The path of the tail tip is indicated by the
mid-line of greater amplitude. The horizontal line
at the lower left indicates about 1/10 second. The
fish’s speed varied from 24.0 to 18.8 inches per
second. The other four fishes have been traced from
still photographs of the same species, Brachydanio
albolineatus, reduced to the same scale, and spaced
as they occurred in their school at closest approach.
The upper fish is in a coasting position.
Text-fig. 2. Idealized diagram of four Brachydanio
albolineatus , one swimming in the track of another,
and one on either side of the latter, beyond the
influence of the lead fish. The larger solid arrows
near each fish show the approximate positions and
directions of rotation of the primary vortices. The
dotted arrows show the approximate positions and
directions of rotation of two of the secondary vor-
tices beside the lead fish. The dotted swirl at the
extreme right, after the following fish, represents
a degenerating and mostly spent vortex. For sim-
plicity each fish is shown in the same state of
flexure. The open dotted lines, starting at the snout
of each fish, show the approximate extent of in-
fluence of the vortex necklaces.
again, join the other side of the fish in such a
manner that they are all rotating with their for-
ward “pushing” side in contact with the fish in a
complicated arrangement of vortices which
Rosen calls a “vortex necklace.” There is no real
wake developed, the vortices simply degenerat-
ing where left. The vortices left by a fish rapidly
degenerate into what Rosen calls a “. . . twin-
armed spiral galaxy which rotates slowly, link-
ing its arm with its predecessor to form a wavy
trail. Its pressure has fallen almost to ambient,
and it has given up the larger part of the kinetic
and pressure energy it once possessed. The vel-
ocity of its particles is quite low, and the water
in the main arms drifts slowly in alternate di-
rections, largely perpendicular to the fish’s path.
The energy in these quiet slow orderly spirals
represents the energy the fish has expended to
propel itself.”
Much smaller and less energetic secondary
vortices occur which Rosen describes as forming
“. . . a zigzag pattern as at the corners of a series
of 60° equilateral triangles. Slightly farther back
on the trail [after the passage of a fish] these
disappear and the main row of vortices makes
its appearance in a single straight line.” The sec-
ondary vortices evidently have little effect, if any,
on locomotion. Rosen points out that this is not
a Karman trail, since that phenomenon covers
the formation of a double row of rearward mov-
ing vortices formed by the passage of a rigid
nonundulating form. These also form alternately
and rotate in the same direction as those found
1965]
Breder: Vortices and Fish Schools
99
about a fish. Viewed from above, the vortices
to the right of the fish rotate clockwise and those
to the left counterclockwise; see Text-figure 2.
The lack of a wake formation by fishes under-
going uniform rectilinear translation has also
been discussed by Hill (1949), and W. Shaw
(1959).
The Karman trail is stable only if conditions
are such that the distances between successive
vortices on both of the sides are 3.55 times the
distance between the two rows of vortices. This
condition exists within a range of Reynolds num-
bers from about 60 to 5,000, below which the
wake is essentially laminar and above which
there is full turbulence. See, for instance. Rouse
(1946 and 1963) or Schlichting (1951). Pre-
sumably if a fish coasted, holding its body rigid,
at an appropriate speed and distance, a common
action in many species, a Karman trail would
appear since the complex pattern described by
Rosen is completely dependent on the undula-
tions of the fish. From this it follows that the
phenomenon associated with rigid bodies, i.e.,
the Karman trail, is completely overriden by
the onset of undulations. This complex flow pat-
tern Rosen considers a third fluid process, which
he calls “Regenerative vortex flow,” being neither
turbulent nor laminar flow.
Evidently much fish swimming occurs at
speeds consistent with the formation of these
vortices, that is, at Reynolds numbers above
those in which full laminar flow is possible and
below those at which extreme turbulence is suf-
ficient to interfere with vortex integrity. This is
evidenced by thevortices shown by Rosen (1959)
to be produced by a small fish, one and five-
eighths inches long, and by Walters ( 1962) , who
made calculations of the Reynolds numbers and
the speed above which laminar flow is not found
for several of the larger scombroids.
The above does not imply that fishes are neces-
sarily limited to this intermediate range of
Reynolds numbers. It is notable, nevertheless,
that the speed of translation of a given school
slows down greatly when, as in “pod” formation,
the individuals give up their usual “standard
spacing” and pack together, eventually reaching
contact. Here not only are the vortices inter-
fered with, if in fact formation of them occurred
at these slower speeds, but in the extreme situa-
tion of approach, the boundary layer itself would
suffer disruption.
The speed of translation of a normally spaced
school is less than the sometimes higher speeds
attained by the individuals in it as they “jockey”
about. Obviously, if the school is to maintain its
integrity the velocity of each fish over a sufficient
period of time must be equal. At least some of
this position shifting is clearly the result of the
attainable speeds possible for given individuals
as related to the amount of moment-to-moment
impingement of others on the individual flow
patterns. This is naturally a very difficult thing
to observe directly because of the complex pat-
tern of interacting forces.
One of the problems involved with observing
the specific action of currents and other hydro-
dynamic features within a school of fishes con-
cerns the presence of gill slits on either side of
the head which expel water intermittently in ac-
cordance with the respiratory activity of the in-
dividuals involved. Not only does the presence
of these respiratory currents become involved
with the boundary layer, but the whole effect is
modified by the kind of fish under consideration.
For instance, as Walters ( 1962) indicates, some
fishes literally pump the respiratory water in at
the mouth and out of the gill slits, as do many
of the Cypriniformes and Beloniformes, while
others such as the Scombroidei have their respi-
ratory movements synchronized with their swim-
ming motions so that the exhalant water is ex-
pelled alternately from side to side always over
the side presenting a surface convex to the flow.
The vortices form, as previously noted, on the
opposite, or concave, side of the fish. The influ-
ence of exhalant water on locomotion without
reference to the effects discussed by Rosen
(1959) was the subject of comment by Breder
( 1924 and 1925) in connection with the offset-
ting of cavitation and the maintenance of the
boundary layer. Here the shapes of the gill open-
ings were noted to vary in different species, being
slit-like in the faster fishes and tending toward
the circular in the slower. Thus the long narrow
slits of the scombroids, which eject rearward a
thin sheet of water along the body surface, were
thought to have much influence on the main-
tenance of an intact boundary layer, while the
more circular orifices clearly were nearly a sim-
ple jet, the utility of which was almost entirely
that of simple jet reaction.
It naturally follows from these considerations
that any attempt to further analyze these matters
must be undertaken with great care in order to
keep distinct the effects of exhalant water from
those of the vortices created by the physical
movements of the entire body. It is clear that at
times the two might work together, as they evi-
dently do in the scombroids, while in other forms
the respiratory component might act merely as
a disrupting influence, or even be alternating in
its influence.
Evidence that these relationships may be very
complicated is apparent from the following find-
ing. Six-inch Carassius auratus Linnaeus, when
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Zoologica: New York Zoological Society
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photographed with 16 mm. Kodachrome at 64
frames/sec., while swimming in a stationary
suspension of bentonite between properly ori-
entated polaroid plates, demonstrated the form
and direction of the water emerging from under
the gill slits.1 In all cinematographic frames in
Plate I, left, this flow issued almost on a vertical
normal to the longitudinal axis of the fish. It
seemed to have an angular divergence of about
five degrees to the rear of this vertical, certainly
no more than ten degrees. This gave a slight up-
ward thrust to the head which could be clearly
seen, in the motion pictures, to be countered by
the pectoral fins, which immediately went into
what appeared to be appropriate countering ac-
tion. When this manner of exhalation takes
place there w’ould seem to be little interference
with the “regenerative vortex flow” of Rosen.
Checking on the motions of both the pectoral
fins and the fluttering of the opercular and
branchiostegal margins of quiescent goldfish
under ordinary conditions suggests that more
usually they drive their excurrent water straight
back and counter its thrust with appropriate pec-
toral movements. Also, in the case of the down-
wardly directed flow, there appears to be a slight
“pucker” of the branchiostegal basket at its in-
ferior median margin, which is absent when the
flow is directed horizontally.
All of the above-mentioned detail cannot be
seen in the small run of frames shown in Plate I,
left. The exhalant water, however, may be seen
as a small dark point, appearing to emerge from
the lower profile of the fish just back of the head,
seen from the third frame from the top to and
including the last and enlarging to a small plume
in the bottom picture. The two top frames are
at the end of the preceding inspiration. The
boundary layer can barely be seen in this series,
in which the fish was moving at about 2.7 inches
per second. It is much more distinct in the mid-
dle set of frames and the right set, where the
1These films were taken in 1946 by the Goodyear
Aircraft Corporation while they were developing a
“water tunnel,” planned to deliver good laminar flow
in an observation chamber at a considerable range of
velocities which could be gradually changed throughout
the possible range. The developers of this device gra-
ciously permitted the study of these films. The device
is now in the possession of the Lerner Marine Labora-
tory.
Bentonite is a mineral, certain forms of which are
composed of microscopic platelets, which are bire-
fringent. Owing to the shape of the platelets, they take
on an orientation which is related to the direction and
velocity of the water currents in which they are sus-
pended. Because of these two features, when used as
described above, bentonite produces a complex pattern
of colored bands. Hydrodynamicists frequently have
used this material to demonstrate detailed features of
complicated fluid flow.
fish was moving at 5 inches and 20 inches per
second respectively. In neither of these is there
any suggestion of a downward exhalation. Evi-
dently in straightforward swimming the exhaled
water passes along the sides parallel to the lon-
gitudinal axis of the fish. Here it becomes in-
volved with the boundary layer, as previously
noted.
The dark, twisted lines in the water which the
fish has passed by are evidently the dying “twin-
armed spiral galaxies” of Rosen (1959) as seen
in lateral aspect. Although the sequences are
short, only 3/32 second from first to last, it is
clear that these are shrinking features that are
not moving in the direction of the fish nor back-
ward from it.
A related feature of respiratory flow, which
is sometimes invoked by fishes but usually neg-
lected in such discussions as the present, is that
many, if not all, species of fishes can and some-
times do reverse this flow. This has been noted
by Townsend (1900) and Breder (1925 and
1926) but otherwise seems to have been over-
looked. Some specialized fishes have developed
the ability to a considerable extent, as, for in-
stance, the Balistidae, which regularly use it to
blow sand away from a burrowing crab or other
morsel. Other fishes that never do such things
can nevertheless expel water from their mouths.
Breder (1925) listed 52 species ranging from
sharks to balistids which had this ability devel-
oped to greater or less degree and indicated that
it was least in the sharks and pie-perciform
groups, and most fully developed in balistids
and plectognaths. Of interest in present connec-
tions is the fact that many of the schooling perci-
forms showed this ability very well developed,
including two haemulids, Haemulon sciurus
(Shaw) and Anisotremus virginicus (Linnaeus)
and six carangids, Caranx chrysos (Mitchill), C.
hippos (Linnaeus), Seriola zonata (Mitchill),
Trachinotus carolinus (Linnaeus) , Selene vomer
(Linnaeus) and Alectis crinitus (Mitchill). The
performances of Toxotes jaculatrix (Pallas) are
probably little more than an extreme specializa-
tion in this detail of behavior.
Since the behavior of water flow concerned
with all the preceding discussion is determined
by the speed of translation of the fish and the
viscosity of the water, values that determine the
Reynolds number, it should be noted that since
the viscosity of water varies inversely with its
temperature, this might be supposed to have
some influence on these features of fish locomo-
tion and aggregating characteristics. The influ-
ence which viscosity variation might have on
such behavior, within tolerable ranges for any
one kind of fish, would, however, not be ex-
1965]
Breder: Vortices and Fish Schools
101
pected to be great. Experimentally, water could
be so treated as to increase its viscosity greatly
by the addition of some inert material such as
methyl cellulose. Since these conditions do not
occur in natural waters, although such experi-
ments might easily show important locomotor
details, they would be too far afield from present
purposes to include here. It is not known what
effect a distinctly greater viscosity would have
on schooling, but it is most probable that the
problem of locomotion under such different con-
ditions, with which a fish could not have had
prior experience, would result in suppression of
schooling and if the viscosity was extreme
enough, would result in complete locomotor dis-
organization.
No effort has been directed toward measuring
the relationship of Reynolds numbers to swim-
ming speed under various conditions of temper-
ature. At best, the many other physical and bio-
logical reactions that are affected by a change
in temperature would be difficult to distinguish
from the strictly locomotor. However, in other
connections, the rate at which a goldfish can
swim steadily at different temperatures, to which
it has become adapted, has been measured by
Fry & Hart ( 1947). This rate rises rapidly from
5° C. to about 20° where it flattens out to about
30° at which point it falls off rapidly to the high-
est temperature measured, 38°, clearly close to
the fish’s limit of tolerance. This curve surely
represents the results of many temperature-in-
duced biological effects, some of which are evi-
dent, but the decreasing Reynolds number would
seem to be one component of the totality of ef-
fects, especially in the limb of the curve from
5° to 20°. Separation of all the influences would
not be easy.
These items need not concern the present
study particularly since all that is needed here
is an understanding of the total influence of each
fish on its near neighbors. However, a recogni-
tion of these details of the nature of the compo-
nents comprising the total locomotor effects
should help make some of the matters directly
relevant to present considerations more readily
understandable.
As the efficiency of this type of undulatory
locomotion depends on the integrity of the fish-
produced vortices, it follows that fishes swim-
ming close together must do so in a manner that
respects these vortices or suffer a considerable
reduction in their locomotor efficiency. Because
fishes in a school normally maintain a standard
distance between each other, the following ex-
periments were performed in order to determine
how this standard distance is related to the size
and location of the vortices.
Most small cyprinids will form temporary
fright schools on slight provocation, a feature
sometimes useful in a study of aggregations, for
instance, see Breder & Halpern (1946). They
used Brachydanio rerio Hamilton-Buchanan,
which readily forms very tight schools on such
occasions. Rosen (1959) used the closely re-
lated B. albolineatus (Blyth). Experiments dem-
onstrated that both species reacted in an essen-
tially identical manner under identical condi-
tions.
A series of electronic flash still pictures were
taken of aggregations of both species at their
tightest grouping. From these photographs, pairs
of fishes, (B. albolineatus), showing the closest
approach, as they formed schools, were selected
for reference to the diagrams Rosen (1959) based
on the same species for his locomotor studies.
Text-figure 1 shows a tracing of one of Rosen’s
diagrams (his Figure 24) based on several succes-
sive frames from his high-speed cinematographs
and compared to fishes from the fright group
direct from our still photographs, all reduced to
a common size. This figure indicates clearly that
the “regenerative vortex flow” patterns of each
fish would not encroach on the active portion of
another fish’s trail so long as they did not ap-
proach each other more closely. This may be
merely a standard feature of this particular
species or a general primary situation in the for-
mation of schools. These, and other observa-
tions, indicate that the side-to-side spacing of
fishes in a school is usually just a little over twice
the distance from the side of a fish to the outer
edge of the trail of vortices in the area of their
production. This insures their integrity until the
fishes have left them behind. As the maintenance
of the integrity of these vortices is important to
the efficiency of the fish’s locomotor efforts, this
may be the controlling factor that determines
how closely fishes in a school approach each
other.
An equation for characterizing a fish school on
a basis of the fish-to-fish distance was developed
by Breder (1954). 2 Comparison with the fishes
used in that study (di/1 of that equation) shows
that Brachydanio albolineatus fits well in this
group (di/1 = 0.30). Table I indicates that this
measure can vary between 0.16 and 0.55 on the
basis of such measurements on a sample of di-
verse species. This situation suggests that the
2The equation follows:
c = a - (fiPi) (f2P2>/ d2
where d = distance between individuals; f = number
of individuals; p = potential of each individual; fp =z
repulsive force; a — attractive force; and c — a measure
of the cohesiveness of the group. Where all p’s are
equal, as in most normal fish schools, they may be
dropped. See the original paper for full details.
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Zoologica: New York Zoological Society
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preservation of these vortices may be the de-
mand which determines the inter-fish distance.
If so, the “di/1” of the equation becomes not
less than one-half the distance a fish must keep
between itself and its nearest fellow in order to
preserve the integrity of both sets of vortices.
Similar measurements of the spacing in a run
of tuna, Thunnus thynnus (Linnaeus), from a
photograph, Plate II, taken eight miles south of
Cat Cay, Bahamas, indicates that the spacing of
these individuals is proportionally greater than
in any of the smaller fishes so far measured, di/1
being not less than 0.50. If the vortex trails are
primarily responsible for the spacing of fishes in
a school, this condition would not be unex-
pected, that is, as size increases, the distance
necessary to maintain the integrity of the vortices
also increases, but faster than the length incre-
ment.
By comparison, a very tight school of juvenile
Mugil cephalus Linnaeus ranging on a sandy
shore showed di/1 to be not less than 0.03+, see
Plate III, lower. The tuna averaged about 6 feet
in standard length and the mullet about one inch.
The measurements of the mullet’s distance is the
smallest so far determined. In these tight schools
there is not much forward motion and the indi-
vidual speeds of each fish may well drop to a fig-
ure at which vortex trails do not form at all.
Whenever fishes in this school had cause to in-
crease their speed, there was always an accom-
panying increase in the distance between them,
as can be seen in Plate III, lower, where a small
marginal group has started to accelerate with an
increase of di/1 to about 0.17— which is not far
from the average of small fishes of other species
previously measured. It should be noted that
Mugil cephalus is the species which so frequently
forms tight pods in which the fishes actually
come into contact and with minuscule forward
motion. No mullet of the size here discussed has
been seen to form pods and the present picture
represents the closest approach to pods by true
schools so far encountered in these studies.
The preceding discussion is concerned only
with the side-to-side relationships of fishes in a
school. The relationships of fishes following
others are somewhat different. Since there is no
wake, the only hydrodynamic influence of any
moment to be expected would have to come
from the dying vortices remaining in a slightly
staggered row. As these subside rapidly it would
not be expected that they would be of any con-
siderable influence. However, it is nonetheless a
fact that in many schools the individual fishes
appear to avoid a head-to-tail, single-file, swim-
ming habit. See, for instance, Plate II. Here, in
a school of nearly 100 tuna, not more than four
can be seen in such a position. While the posi-
tions of individuals are more or less continually
changing, this situation is common in schools
of many diverse species of fishes. In the single-
file, follow-the-leader, position the trailing fish
should receive whatever residual energy that may
be left in the expiring vortices of the lead fish,
as is indicated in Text-figure 2. Such energy
would have its influence at primarily right angles
to the course of the fish, alternately left and
right. The secondary vortices at this time would
not be expected to be influential. Further to
either side the trailing fish would be out of the
possible range of hydrodynamic influence of the
lead fish. The position where a definite retarding
influence would be felt, indicated by dotted lines
in Text-figure 2, is precisely the position in which
fishes are not apt to be found in a school unless
they are further to the rear of the lead fish than
those shown. As is clearly indicated in the figure,
the fish would be swimming into the “wrong”
side of the vortices. This distance may, in fact,
be a measure of how far rearward there is any
energy left in these vortices.
The evidence shown here for the existence of
these locomotor vortices gives a more solid basis
for the general views, more or less vaguely ex-
pressed, of inferred benefits to be derived from
birds and fishes progressing in groups. The well
known “V” formation taken by many species of
birds in flight and the staggering of individual
fishes swimming in groups has been noted by
many, for instance Breder (1926) and Matschin-
ski (1953).
The remaining dimension to be considered,
that of fishes arranged in a school of more than
one layer deep, again presents another situation,
different from the two horizontal dimensions.
Since the fishes undulate from side to side, these
two dimensions are the ones directly involved.
The only disturbance present in the third dimen-
sion is incident to the vortices crossing over from
side to side about the body of the fishes as indi-
cated in the diagrams of Rosen (1959). This
disturbance is slight and fishes swimming in
many layers do not regularly leave as much
swimming room above and below themselves as
they do in either horizontal direction.
Obviously fish schools vary widely among dif-
ferent species and in one kind under varying
conditions. Thus schools such as those shown in
Plates II through IV, while common enough, are
sometimes replaced by fishes swimming closely
head-to-tail in long trails. Such groups are not
very common nor well understood. It is thought
though that this type of behavior is not espe-
cially related to locomotor convenience, but to
other biological necessity.
1965]
Breder: Vortices and Fish Schools
103
Sensitivity to the water movements induced by
other fishes might be conceived of as being
mediated proprioceptively through necessary
changes in muscular tension accompanying
changing swimming efforts in response to cur-
rent changes. This would, of course, be in addi-
tion to the optical response, as the speed of pas-
sage changes the view in accordance with small
accelerations and decelerations. In addition,
most fishes are abundantly supplied with special
sensory devices involving the whole lateral line
complex. Moreover, van Bergeijk (1964) indi-
cated that apparently the lateral line organ is
employed as a near field acoustic detector and
the swim bladder-ear system as a far field de-
tector. This is in keeping with the view that the
lateral line cupulae are primarily displacement
receptors. Located as they are, it would be
strange indeed if they did not supply cues about
water movement. It would seem that the multi-
plicity of possible information paths gives a
measure of the importance of cues in this con-
nection and could conceivably go far in its total-
ity to account for the more remarkable unani-
mous wheelings and turnings of large schools.
The above would in no way invalidate the ideas
that aggregations in the dark may be prevented
from wandering too far from each other by
means such as auditory cues as, for instance,
indicated by Moulton (1958). Only the serried
ranks of schools being fully dependent on vision
would disappear. The general ability of fishes
to avoid obstacles in the dark by sensing differ-
ential water pressures should keep them from
collision.
A close inspection of Plate III, lower, reveals
a series of thin, light, wavy lines above the
school, especially prominent over its highest
point and running similarly to the left almost to
the rather pointed left and tail end of the school.
Lesser similar lines are to be seen adjacent to
other margins of the school. It is to be noted that
at no place remote from the school do these lines
appear. This condition was found to be the case
in the dozen other photographs made of this
school during this one observation session. No
other photographs taken by or seen by the au-
thor have ever showed this feature. It is believed
that the appearance of these lines is caused by
refractive peculiarities induced by some unno-
ticed optical circumstances present at the time
these photographs were taken. Examined in re-
lation to the degenerating vortices shown in
Plate I, it is thought that these are the composite
water disturbance induced by the whole group.
It is also to be noted that no such features are
to be seen at the advanced, right end of the
school, where they could not be formed in any
case.
It was mentioned in the Introduction that only
schools would be discussed in detail. The reason
for thus limiting this paper is that the present
state of knowledge of the influences of fish-gen-
erated vortices over distances greater than those
found in schools is nil. If there is any energy at
all left in them by the time they are reached by
another fish in a non-polarized aggregation, it
is not detectable by present methods. Thus, it is
not considered profitable to go into such a specu-
lative area at this time. The effects, so far as
known, in what Breder ( 1959) considered as un-
stable internodal positions between school and
pod, have been discussed in the preceding para-
graphs.
Another, and related matter, which will not
be taken up, is that of the approach of schools
to the surface, bottom or solid obstacles. Again,
there are so little data on the hydrodynamic as-
pects as to preclude little more than bare specu-
lation. It is noteworthy, however, that the ap-
proach of schools to the surface or the bottom is
much less restricted than to vertical solid sur-
faces. This would seem to relate, in part, to the
fact that the water disturbances produced by
fishes are primarily lateral, because of the geom-
etry of their propulsive mechanisms. Plates III
and IV, especially, indicate the lack of reluc-
tance of various types of schools to approach
surface or bottom. The much greater reluctance
to approach solid objects laterally is especially
noticeable about piles. A considerable amount of
this reaction is mediated through the optical
system. It has been shown, in one species at least,
that approach to a light-colored object will be
closer than to an otherwise identical but dark
object, Breder ( 1 95 1 ) . In this case the fishes ap-
proached the dark surface to within about one
and one-half times their own length while they
approached the light surface to about half of
that distance. Because of this condition and the
general complication of the situation, as well as
the inherent difficulties in trying to establish the
hydrodynamic values contributing to this be-
havior, if, in fact, any are involved, it is, again,
rather beyond present means of detection.
Extrinsic Vortices
The term “extrinsic” is here used to cover
vortices that have influences on fishes, other than
those intrinsic to the locomotor activities of
fishes themselves. They cover all the physically
caused vortices, most usually those created by
water currents. Commonly such are to be found
in flowing water where the presence of various
kinds of obstructions develops viscous shearing
forces that lead to various degrees of turbulent
flow in which the vortices are swept along, or to
standing vortices where eddy formation occurs.
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In the case of a rapidly flowing stream, such as
a typical trout stream, flow at a given point may
vary from the almost laminar, through inter-
mediate stages to the violently turbulent. Speed
of flow and the geometry of the situation deter-
mine the particular condition found. Superficial
observations show that fishes are forced to ad-
just their locomotor activities according to the
conditions. Thus, in a nearly laminar flow of a
sufficiently sluggish current, fishes may be seen
rather easily stemming the current at an equal
and opposite speed and holding a place, either
as a solitary individual or as a stationary school,
sometimes for long periods. A valid verification
of the character of the flow can usually be ob-
tained by observing the paths of fine particles,
either naturally present or artificially supplied.
In cases where the speed of flow exceeds that
at which essentially laminar flow is possible, the
aquatic equivalent of “dust devils” may be seen
under certain conditions where the flow passes
over a fine sand bottom. These are, of course,
caused by vortices resulting from separation of
boundary layers around some obstruction, up-
stream from where they become noticeable. Act-
ually, such a stream is more or less filled with
Karman trails which interact with each other in
a complex fashion that is not easily recognized
by simple observation. Because of the speed of
flow and the complex nature of the vortices being
swept along in series, ordinary swimming be-
comes impossible. Under such conditions fishes
are to be found stationed behind some large
rock or other sheltering obstruction. From time
to time they may dash out into the flow and
zigzag at great speed to some other sheltered spot
further upstream, or drop downstream, while
heading into the flow, to some other retreat. Al-
though it is difficult to prove by direct observa-
tion, every appearance indicates these zigzag sal-
lies in such fast flows are conditioned by the
presence of vortices passing downstream within
the general flow. It would seem likely that the
fish are taking advantage of the lessened flow
downstream on the side of the vortex which is
moving countercurrent. In fact, taking advan-
tage of these features may be the only means by
which such fishes are able to negotiate flows as
strong as they can be observed to negotiate. At
least, when the flow becomes truly turbulent, as
can again be checked by the erratic movement
of particles, most fishes do not even try to buck
the flow. Under these conditions only relatively
large fish ever hazard such attempts.
The Fish Mill as a Vortex
The fish mill, a closed-figure fish school, first
analyzed by Parr (1927), was considered by him
to be a structure in which schooling fishes are
sometimes trapped, which remains in one place,
while all the fish follow each other in a more or
less circular path, until some exterior event
breaks up the formation. Parr described the con-
ditions under which a mill could form in accord-
ance with his observations. This is no doubt
about the manner in which schools are frequent-
ly formed, but since the time he studied the sub-
ject, data have been obtained which indicate that
there are, in addition, other causes leading to
mill formation, perhaps many.
Types of Mills
Extrinsic mills.
Parr's mill.— The mill formation described by
Parr loc. cit. may be briefly defined as depending
on some extrinsic agency, such as an obstacle,
deflecting the anteriormost members of a nor-
mally advancing school so that they see the pos-
terior members and turn to join them. This act
closes the circuit and forms promptly into a typi-
cal circular mill.
Flow pattern mill or current-induced mill.—
Wherever a flow encounters a projecting obsta-
cle, a standing eddy forms in its lee. Under cer-
tain circumstances these may be of considerable
stability, as simple field observations can sub-
stantiate. Sometimes mills of fishes are to be
found circulating in them in a direction always
opposite to that of the circulation of the water as
indicated in the preceding section. It is easy to
imagine how such fish mills could be established,
but quite another to provide it rigorous proof.
Apparently all that it is necessary to postulate
is a school counterswimming the main flow in
the neighborhood of an eddy. If the school
should approach the shear line between the eddy
and the passing main stream, the tendency of
fishes swimming countercurrent to seek quiet
waters after a time of stemming a swift flow
could account for the school inching over into
the less rapid induced flow and forming a mill
concentric with the eddy.
Special cases.— Various activities of man some-
times cause the formation of fish mills. These
may be induced in manners identical with those
described above, usually by engineering work
involving modification of shore lines or other
changes in features of the physical environment.
Other types of man-induced mills may form on
novel bases not previously possible. It is well
known that strong lights placed close to the sur-
face of the water or submerged, sometimes for
the purpose of attracting fish, may induce mill
formation by those attracted. Such a mill will
have the light at or over its center; see, for in-
stance, Miyadi (1958). The mechanism involved
here is too obvious to warrant comment. In this
1965]
Breder: Vortices and Fish Schools
105
case the mill is pinned down to a stationary posi-
tion in relation to the light, for such mills dis-
perse on extinguishing the light or can be made
to follow the light if it is moved about slowly.
Intrinsic mills.
Viscous shear mill— Mills often form when
there is no obstacle or other evident extrinsic
influence on the leading members of an advanc-
ing school. Such a condition was described by
Breder (1959) as being observed in schools of
young Ictalurus. Since then further observations
have been made on similar behavior of approxi-
mately three-inch Mugil cephalus. It was possi-
ble in one instance to take serial photographs of
the process which show the essential action.
Plate IV shows a rather infrequently seen form
of intrinsic mill formation. This is apparently
the only photographic evidence that a forward-
moving school, through very quiet water and
with clearly no exterior interference, will so be-
have. This action was photographed in a tidal
basin, thirty feet in diameter, in almost the slack
water of high tide. The school happened to be
heading into the flow as the first photograph was
taken. Previous to this, it had been wandering
about in various directions. At no time did it
approach the shore closer than is indicated in
the photographs, by the foreground grass-heads.
A very light breeze was gently riffling the water
surface from the upper right. That this had noth-
ing to do with mill formation is clear, because
the same action has been witnessed in dead
calms. In fact, in the perhaps dozen times this
particular type of mill formation has been seen,
it has mostly occurred in extremely quiet water.
The impression has been that the slightest exte-
rior influence would completely inhibit the be-
havior. The present case happens to be the only
instance when it was possible to make such pic-
tures in rapid succession.
The exact forces at work are still not certain,
but may well be associated with a shearing action
within the school that develops when irregulari-
ties appear in a school of fishes advancing in
closely parallel rows and, in terms of hydrody-
namics, behaving almost as a simple laminar
flow. In the formation of a fluid vortex evidently
both viscous shear and inertial effects are in-
volved, see Rouse ( 1 963). That he questions some
of the current theory involved does not, however,
concern present purposes, for whatever the out-
come it would not alter the possible effects of the
fish-generated vortices. Prandtl (1904) showed
that the occurrence of such perturbations of a
sheet-like flow can only lead to amplification, so
for the implied convergence of the streamlines in-
volved, according to Bernoulli’s theorem, there
must follow a rise in velocity and a drop in pres-
sure, leading to further asymmetry of the flow,
and finally to a series of vortices. Because of the
sizes of the fish schools that have been under
observation, hardly more than one vortex could
be expected in a single school if the formation
of an intrinsic mill follows these hydrodynamic
principles. Perhaps if two started to form, one
would neutralize or engulf the other.
Sparring mill— While peck-order is evidently
almost negligible or absent in the most persistent
schoolers, there are other fishes that form “fright”
schools or other temporary aggregations. Such
a case would be illustrated by Astyanax, dis-
cussed at length by John (1964). He described
two fish circling each other, in the absence of
other individuals, and indicated that this could
be the beginning of school formation. It might,
however, be quite the contrary, and actually
represent the “sparring” of two antagonistic in-
dividuals in a somewhat “stylized” manner. If
this type of behavior ever occurs between two
individuals in a large school and leads to mill
formation, it has not been recognized, for there
have been no such instances reported.
Bearing on the above are the studies of Okuno
( 1963), who, by means of studies in the sea and
in large and small aquaria, reported that fishes
which formed stable schools in the sea and in the
large aquaria did not pursue one another in small
aquaria, whereas all other types showed some
sort of pursuit of their own kind or of others.
The latter included types that formed unstable
schools similar to those of Astyanax.
General Considerations on Mills
Since it might not be apparent that there is
an adequate justification for comparing the
purely physically-induced movements of fluid
particles with the biological activity of swim-
ming fishes, the following explanation is given.
No objection would be expected from the hydro-
dynamicists, as they have no qualms about com-
paring the flow of automobiles along a highway
with the flow of water in a stream.
As all biological activity is restricted by the
physical limitations of the organism as well as
the physical limitations set by the environment,
it is generally useful to assay a given situation
as to what part of an organism’s activity is rigidly
enforced by the environment and what part is
further limited by the constitution of the organ-
ism. This then makes possible a determination of
what might be called an organism’s “degree of
freedom.” These differences are not always easy
to distinguish except in a gross way, but one of
the present purposes is to attempt to delimit what
part of schooling is forced on a fish and what
part is subject to adjustment by the individual.
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The latter portions of the observed behavior
would be expected to be those showing the great-
est variations in environments that, while seem-
ingly identical, reveal fishes doing a number of
different things, whereas the most rigid and
stereotyped behavior would be suspected of be-
ing a mandate primarily imposed by immediate
physical necessity.
A fish school does not form because of a cen-
ter of attraction, but by the mutual attraction of
each fish to others. Fish mills, however, may be
formed by exterior or interior perturbations, as
previously indicated in the list of types of mills.
Only an intrinsic mill evidently is formed be-
cause of a central disturbance, which may be
comparable to the hydrodynamicists’ viscous
shear in the generation of vortices. Breder (1951)
showed that a mill of Jenkinsia rotated, with the
nearly axial fishes swimming much more slowly
than the peripheral ones, but that there was
much slippage between members, so that, al-
though the peripheral fishes were moving faster
than the nearly central ones, the school was not
rotating as though it were a solid wheel. Fish
mills resemble standing eddies rather than a
wash basin vortex or a hurricane. Because the
rotational flow of standing eddies is induced and
maintained by the influence of the passing flow
along the shear line, it follows that flow of the
eddies is moving fastest at their peripheries and
slowest near their centers of rotation. This fea-
ture resembles that of the mill just noted. At
certain rates of flow and conditions of turbulence
of the passing stream, the eddy breaks up in an
irregular series of smaller eddies moving along
the shear zone, as a form of Helmholtz insta-
bility. Only under certain conditions, involving
the geometry, the rate of flow and the viscosity,
will a fairly stable eddy be formed.
Vortices of all sorts are controlled by inertial
and viscous effects, which are in opposition to
each other, the first tending toward eddy forma-
tion and the second tending to dampen eddy
formation and leading to eddy destruction. If it
is proper to refer these effects to a fish school,
this would imply that a school continues in its
direction of motion until it is altered by some
influence, which could be either extrinsic or in-
trinsic and that all retarding effects interfere
with the integrity of the group. Obviously this
statement could be rewritten for a single fish and
it would be equally valid, but probably not worth
saying. However, in connection with a group
and the formation of mills it holds some interest.
If the cohesiveness of the school be equated to
viscosity, we could then discuss the formation
of intrinsic mills in terms of viscous shear and
inertial effects. This could involve a study of the
relative strength of the forces of cohesion from
fish to fish and the readiness with which a fish
transfers from immediate companions to others.
It could also consider the relative influence of
small differences in the deployment or in the po-
tential of companions to the right as compared
with those to the left of a given individual. It is
at this level of integration where intrinsic mill
formation should be expected to develop. Pos-
sibly here, too, a distinction could be made be-
tween inertial and viscous effects. They might
appear respectively as overshooting companions
or as laggards. This would also be the equivalent
of an overly sensitive and consequently over-
shooting pen on a paper tape recorder as
compared with one that is sluggish because of
overdamping. Probably in a given school the in-
dividuals are in a fairly narrow spectrum of de-
gree of reactivity. These differences in reactivity
would be expected to be distributed according
to some more or less normal frequency, with the
bulk of the individuals showing the peak occur-
ring near the mean or mode with many fewer at
the high and low extremes. If this is in fact
the case, then one would expect the compara-
tively few high and low reactors to have much
more influence on alterations in the behavior of
the school than the large numbers with inter-
mediate reactions. This small extent of behav-
ioral variation probably measures the amount
of information present in such a school, which
is obviously a system of great redundancy.
Pertinent to the preceding comments on the
behavior of fishes within a mill, but also common
to all schools, is the easily observed feature that
the fishes which comprise them do not retain
fixed positions relative to each other but are
more or less continually “jockeying” from one
position to another. One apparent reason for this
is evidently that they are all adjusting their
speed at any moment to that of their nearby
neighbors. That schooling fishes do not adjust
precisely to moving targets has been nicely
shown by Shaw & Tucker ( In Press) . They used
an opto-kinetic device in which a circular target-
bearing drum rotated concentrically around a
transparent circular tank. The target was a dark
band on an otherwise immaculate surface. The
fish to be tested were placed in the tank and
would follow the band around through a con-
siderable range of speeds, a fact that has been
known to be the reaction of a variety of fishes.
In this case records were kept of the locomotor
behavior of the fish under test. At a given uni-
form speed of target, one species, Caranx ruber
(Bloch), tended to overshoot the target, that is
to swim around the aquarium a few more cir-
cuits in the time alloted than the drum rotated,
while another, Selar crumenopthalmus (Bloch),
1965]
Breder: Vortices and Fish Schools
107
lagged slightly behind the speed of the drum. It
is noted that the first-mentioned is a considerably
faster-swimming fish. The difference in behavior
may well be caused by a conflict between the
tendency to follow a moving object with that to
swim at a speed relative to the species’ natatorial
ability, its size and the extent of fatigue. This
effect, by itself, would seem to be sufficient to
account for the continual adjustment commonly
seen in schools.
If the effects of the trail of vortices be added
to the above influence, in which individual fishes
are slowed down momentarily by running into
the “wrong” side of the vortices produced by
some other fish as against those which happen
to run into the “right” side of such vortices,
there is an added purely mechanical factor tend-
ing to produce irregularities in the velocity of
the individual fishes. This, however, should con-
tribute little to variation in the forward velocity
of the school as a whole, since these differences
should be largely symmetrical and consequently
self-effacing.
In the case of great differences of size of in-
dividuals swimming together, as pilot fishes
(Naucrates) with large sharks, the situation is
apparently different. Shuleikin (1958) reasoned
that when a shark is moving rapidly the pilots
could not possibly keep up with it unless they
occupied positions within the boundary layer of
the shark and were thereby swept along. Obvi-
ously, they are not so restricted when sharks are
moving slowly. Whether the “regenerative vortex
flow” of the shark also enters in as an assisting
agent has not been studied, but it would seem
to necessarily follow that it would, at least at
some times. This entire matter suggests the need
of further study as no one knows how long a
pilot fish will stay with a given shark or whether
the latter frequently loses its attendants when
swimming for long distances at high speed.
Disruption of Vortices and Schools
The disruption of mills and vortices by fright
or violent disturbance is sufficiently obvious not
to need elaborate discussion at this point. How-
ever, it may be noted that acceleration of fluid
flow will destroy a vortex and prevent vortex
formation and lead only to violent turbulence.
See Rouse (1963) for a discussion of these fea-
tures and those of “viscous decay” and inertia.
Mild fright will usually cause first a sudden ac-
celeration of the individuals in a mill or school
and then lead immediately to disruption. With-
out pushing this resemblance too far it may be
noted'that in both fluid flow and fish assemblages,
return to the prior condition is normally prompt.
Plate III, upper, shows a school of three-inch
Mugil cephalus exploding in fright at the near
passage of a kingfisher. This school had formed
a mill, as might be inferred from the radial ar-
rangement of the dispersing fishes. In a school
that is not a closed figure, the usual dispersal
lines merely fan out from the advanced end of
the school. This is the same school discussed
under Viscous shear mill and illustrated in Plate
IV.
The velocity of advance of a school, as indi-
cated earlier, must be precisely related to the
velocities of its constituents. If it is not, the
school disintegrates. There is evidently a range
of possible speeds of translation of the school as
a whole, only within which it is possible to main-
tain an intact school. Below some critical speed
of school advance, in still water, it would appear
that spontaneous individual differences in orien-
tation, without the steadying effects of sufficient
forward motion, are insufficient for the mainte-
nance of polarization. At this point the school
dissolves to an aggregation. The same situation
obtains in a stream flowing past a “standing
school.”
At the higher velocities attained by schools,
as with a burst of speed, there is usually a con-
siderable loosening of the school and often com-
plete disorientation as well, as in Plate III, upper.
Bursts of speed in a school almost always follow
a fright and are usually otherwise absent except
in the planktonic feeding of some forms. At these
times it is difficult, if not impossible, to discern
how much the loosening is referable to a “gen-
eral dispersal response,” and how much is refer-
able to the locomotor demands of the increased
speed.
Bainbridge ( 1958a and b) and Bainbridge &
Brown (1958) have shown that, in fishes em-
ploying undulatory body movements for locomo-
tion, at least, an individual twice the length of
another will travel twice as far if the frequency
of their tail beats is identical, according to the
formula:
V = y4 [L(3f — 4)]
where V = velocity, L = length of fish, and f —
frequency of tail beat. This relationship evidently
holds for fishes up to 12 inches in length and
perhaps considerably larger. It is assumed that
such comparisons are to be made between fishes
of like species and condition and that the ampli-
tude of the tail beat is equivalent. These condi-
tions very probably suffice to restrict the vari-
ability in size of the fish in a school to the small
ranges that have been observed. Measurements
of the ranges of the length of fishes, given as
ratios within a school, of the smallest to the larg-
est member, have been made by Ohshima (1950)
for Plotosus anguillaris (Bloch) 0.65, Schaefer
108
Zoologica: New York Zoological Society
[50: 10
(1948) for Thunnus albacares (Bonnaterre) 0.73
to 0.50 with a mean of 0.61, and Breder (1951)
for Jenkinsia lamprotaenia (Gosse) 0.61. Some
of these are evidently extreme because of the
methods used, for at least in Thunnus there may
have been portions of separate schools inad-
vertently mixed in their capture. It is to be noted
that the first and last species are within the range
shown for Thunnus and that Ohshima found that
schools broke up if the range he gave for Plotosus
was exceeded. These data together with similar
measurements on other species are given in
Table I.
It would seem that as differences in the lengths
of fishes within a school approach the condition
where one individual would be twice the size of
the others, schooling no longer occurs. This is
also the point at which the larger is able without
special effort to swim twice as fast as the smaller.
Certainly no stable school of a homogeneous
kind with such a size range has been reported.
It is also notable in this connection that Bain-
bridge ( 1958a) indicates that the ability of fishes
to sustain periods of swimming is proportional
to the length of the fish, but is related to it dif-
ferently in different species.
The adjustment of differences in speed can
ordinarily be easily seen in most fish schools, the
slower ones increasing the frequency of their
tail beat as well as increasing the amplitude of
the tail’s oscillation. Fishes outrunning the others
sometimes adjust by merely swimming slower,
but most frequently simply “coast” by holding
their bodies straight until the speed is suitably
slowed, as is indicated in Text-figure 1 by the
posture of the upper individual. Evidently such
accommodation to one another’s normal pace is
not acceptable beyond the size limits indicated
in the preceding discussion and may be one of
the primary causes of school dissolution. Since,
so far as known, schools become aggregations in
complete darkness there may be a considerable
amount of re-formation and dissolution with the
return of light, resulting in the degree of uni-
formity ordinarily found in schools by the time
it is light enough to make satisfactory observa-
tions under the usual field conditions.
Related to this but at the opposite end of a
series are the cases where different species of
fishes mingle as one group in certain parts of
their life history or under certain conditions of
environment. Such a case for Girella punctata
Gray and G. melanichthys (Richardson) has
been reported by Okuno (1962) where the young
of both species form common schools in the
middle parts of a bay but keep separate in all
other localities. This would seem to be related
to the conditions found with the cyprinid Note-
migonus crysoleucas (Mitchill) and the cato-
stomid Erimyzon sucetta (Lacepede) reported
by Breder ( 1959) . Here the young fishes aggre-
gated or schooled during the daytime but passed
the night in separate places. The opposite of this
was also reported in the same paper where two
kinds of fishes ( Jenkinsia lamprotaenia and An-
choa hepsetus (Linnaeus)), very similar in ap-
pearance, to human observers at least, firmly
maintained two tight and separate schools. What
visual differences caused them, at the distance
at which they turned, to avoid one another is
still unknown.
If the minimum normal swimming distance
between side-to-side fishes in a school is listed
according to the absolute size of the individuals
a rather interesting relationship may be estab-
lished. It is much easier to take photographs of
a school from above than to obtain precisely
accurate measurements of the individuals in the
same school. Therefore, the listing shown in
Table I. Ratios Characteristic
of Fish Schools
First column, species arranged in terms of rank
of absolute size of fishes, from smallest to largest;
second column, ratio of fish lengths to minimum
distance apart of fishes in a school; third column,
ratio of smallest to largest fish in a school.
Distance
Size
Species
Between
Ratio
lctalurus nebulosus
. . . 0.20
Mugil cephalus
. . 0.17
Brachydanio albolineatus . . .
. . 0.30
Jenkinsia lamprotaenia
. . 0.25
0.761
Atherina stipes
.. 0.18
0.75
Sardinella macropthalmus . .
.. 0.16
0.87
Selar crumenopthalmus . . . .
. . 0.49
Strongylura notata
. . 0.55
Thunnus albacares
. . 0.50
0.612
1From Breder (1954). Another school, under other
conditions; Breder (1951) gave a value of 0.61. Other
data except as noted below are from Breder (1954) or
are new. Plotosus has been omitted from this table
and Text-figure 3, because of various difficulties in in-
terpreting the data.
2From Schaefer (1948). This figure is a mean of a
number of schools which varied from 0.73 to 0.50. On
the basis of the other data it would seem that the lower
figure must represent a very unstable school or perhaps
two separate schools mixed in the catching. Although
the figure is included here, as the only one available,
it is doubtful that it is valid for present purposes. No
values for apparently normal schools of the interfish
distances were obtainable and size ratios extended from
groups ranging from 6.2 to 4.9 cm. with a size ratio
of 0.79 to one of 2.3 to 1.8 cm. with a size ratio of
0.78. However, there were three intermediate groups
which had size ratios extending from 0.74 to 0.78. Some
of these groups would be in the second place and some
in the third and fourth places in this table. The insertion
of these data would not modify the opinions expressed
herein.
1965]
Breder: Vortices and Fish Schools
109
Table I has been arranged according to rank of
absolute size of fishes named, a matter that is
relatively easy to estimate with great accuracy.
When these data are plotted as in Text-figure 3,
it is at once evident that distance between fishes
in a school approximates a linear relationship
between the length of the fishes in terms of rank
order and the minimum distances between the
individuals comprising a school in terms of per-
cent of fish length. Although the scatter is con-
siderable, the graph reaches over a range of
lengths of about one-half inch to about five feet
or more. This may be a measure of the increase
in the diameter of the vortices. Perhaps the scat-
ter is no more than should be expected when the
diverse nature of the body forms of the fishes
included is considered. Included in Text-figure 3
is a comparison of the range ratio of fish lengths
compared with the absolute size rank. Here,
as would be expected, there is no evidence of a
drift with increase in length of the fishes con-
cerned.
Other more obscure features may be perhaps
best illustrated by the following observations
made on feeding groups of young Mugil cepha-
lus about 25 mm. long. When feeding vigorously
in shallow, clear water, the following sequences
may frequently be seen. For example, a group
of about one hundred such fishes was seen feed-
ing, on the bottom, with the peculiar side-to-side
movement of their heads as they scraped algae
off stones and shells. At such times usually not
more than half the number were engaged in this
feeding activity. The non-feeders would be found
to be above the feeding group as a random ag-
gregation. Mostly they would be very quiet but
one might make a short swimming movement of
about twice its length, at which one after another
of the non-feeders would line up and follow the
first, forming as they did, a proper school which
would then stream off as a long, thin school, per-
haps for a distance of twice the original school’s
diameter, and then settle down and feed. It
seemed as though the first fish which initiated
the school would swim away from the group as
a consequence of the others all swimming toward
it and not that this initial fish separated from the
feeding group of its own activity. The other half
(the feeding half) paid no attention but con-
tinued feeding until it had probably removed
most of the edible portions of the area. At this
time they would stream off as a school and settle
on a new spot to again scrape algae as a loose
aggregation. After these settled it was noticed
that not all were feeding and like the previous
group about half were stationed above the feed-
ers. Since this whole group contained only about
50 fishes, the 25 non-feeders which streamed off
to find another feeding ground were about one-
Text-fig. 3. Ratios characteristic of fish schools.
Order of magnitude = Lengths of fishes in order
of rank. Index value for lower line = ratios of
fish lengths to minimum distance apart; for upper
line = ratios of largest to smallest fish in a school.
See text and Table I for full explanation.
quarter of the original group. This same thing
occurred with the other school of 50 so that
shortly there were four small schools of roughly
25 fish each.
The return cycle occurred when two of the
non-feeding roving bands encountered each other
and merged. During the period of observation
there were many shifts of this sort, back and
forth. When the observations were terminated,
after about one hour, there was one group of
about 75 and another of about 25. It is not to be
supposed that this type of school dissolution and
merging is especially common, but that it does
happen gives some idea of the complexity of the
basic pattern to be found in these fishes. More
usually these features are so masked by various
irrelevant details that only fragments of this
action may be seen. There is, unfortunately, no
way of distinguishing individuals, so it is not
known what the minute-to-minute history of a
single fish was in any instance. It would seem
possible, however, that the fish that formed the
feeding part were mostly those that had formed
the non-feeding part in the prior situation.
Vorticity in Other Systems
The determination of various features of fish
schools, especially as related to the water move-
ments generated by the locomotor activities of
the massed fishes, has naturally led to a variety
of considerations borne upon by current thought
in other fields of activity. The following com-
ments indicate similarities and differences be-
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Zoologica: New York Zoological Society
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tween vortices found associated with fishes and
found in other vortical situations.
In any study of animal assemblages it should
be recognized that in the inanimate part of an
environment a variety of physical forces causes
non-locomotor, living or non-living, objects to
assemble in groups, some even with a structure
not unlike that of a fish school. In all assem-
blages there is evidently some part which is
a mere submission to direct physical forces. In
fact, one may consider part of animal activity
to be as much a struggle to keep animals from
being inertly accumulated in groups by these
physical forces as it is a struggle to assemble in
groups useful to the species. Reference to studies
in other fields, not concerned with biological
matters, underscores this condition : for instance,
in cloud groups, Malkus (1963); in hurricanes,
cyclones, galaxies and water masses, Rouse
(1963); in physicists’ order from disorder in
particles, Purcell (1963); and in terms of gen-
eral reference, as leaves caught up in a swirl of
wind or water and iron filings in a magnetic field,
Breder & Halpern ( 1946) . In all these as well as
many others the assemblage has been sorted by
the physical forces involved so that the items
usually are nearly all of a single “species” with
little jumbling of unlike things together.
Since fishes in a school are usually equipoten-
tial or nearly so, they are clearly redundant from
the view of information theory and the larger
the school the greater the redundancy. Schools
vary greatly in size within a given species, some
of the size differences being associated with the
ecological and developmental condition of the
participants and some associated with incidental
details. Thus, the size of the schools of Mugil
cephalus, for instance, increase greatly during
the reproductive season while at other times the
schools are usually much smaller but more num-
erous. As it is presumed that these assemblages
have some utilitarian value, related to the life
processes of the species concerned, the question
of what determines an adequate redundancy,
what is too much and what is too little, would
seem to be of importance. This question can be
discussed without immediate reference to the
specific manner in which schools operate. It
would seem that here is a situation that selection
could easily alter. There is a variety of hypo-
theses and theories of the selective value con-
cerning schooling versus non-schooling, as in
Sette ( 1950) , Atz ( 1953) , Verheijen ( 1953 and
1956), Keenleyside (1955), Schafer (1955),
Brock & Riffenburgh ( 1960), Brock ( 1962) and
Olson ( 1964) . These ideas, however valid some
of them may be, are not in sufficiently specific
form to be applied directly to present consider-
ations.
If the equations of lohnson (1963), devel-
oped for a study of the relations of tissue redund-
ancy to aging, be applied with suitable modifi-
cation, to the size attainable and the length of
time a fish school may exist, they would seem to
have validity in terms of the present study. In
this sense, a single schooling-type fish, n = 1,
should possess no redundancy and should be un-
stable. This certainly checks with the observed be-
havior of an isolated but normally schooling fish.
Larger values for n lead to greater redundancy
and stability. This, in present terms, should mean
that the larger the number of fishes in a school,
the greater length of life for the school. Since
curves of the family developed by lohnson loc.
cit. can reach very large values of n, without
substantially altering their basic nature, there
would appear nothing in them to suggest a theo-
retical upper limit at which size a school would
begin to lose integrity, unless limitations be set
for the capacity of the environment or some un-
known attribute intrinsic in a given species.
A consideration of the relationships within
a fish school in reference to ideas centering about
notions of “emergence” and whether a group is
a mere aggregate of its parts or possessed of a
“wholeness” of its own, leads to some interesting
points. All such discussions are dogged by the
inherent vagueness of many of the terms and
concepts necessarily employed. Confining the
study to fish groups brings in the possibility of
being a little more precise in the handling of con-
cepts which do not have to pretend to have uni-
versal application. A useful discussion of the
semantics of notions about “wholes” and “parts,”
used in the broadest possible sense, is given by
Nagel (1963).
Limiting the view to model groups in which
all members are perfectly equipotential, the fol-
lowing conditions should obtain. In an equipo-
tential model of a fish aggregation the only dif-
ference between it and a scattering of solitary
individuals is that the fishes in the aggregation
maintain themselves in a close association, with-
out regard to orientation. The corresponding
model of a fish school reduces the random nature
of the fish orientations to one of regular order
in which parallel swimming is the predominant
feature. One of the results of this polarization is
that the constituent fishes may be more closely
packed and still retain adequate swimming room.
By stipulation these two models of fish groups
contain no other information than that given
above and would seem to be at the very bottom
of a series of organized animal groups, showing
perhaps the first two steps which would have to
be established as a basis for further structural
complications. Although obviously many possi-
bilities could exist, a conceivable next step could
1965]
Breder: Vortices and Fish Schools
111
be the establishment of pod formation and still
later, peck order.
In this one possible arrangement, there would
be (a) mutual attraction to a standard distance,
(b) polarization, (c) contact, (d) hierarchy. It
is to be noted that these items are not all operat-
ing in the same direction. The addition of (b)
to (a) tends to knit the group together. The ad-
dition of (c), the contact pod, to either (a) or
(a) + (b) would seemingly make for an even
more cohesive group, but the addition of (d)
tends to disrupt either (a), (a) + (b), (a) -f
(c) or (a) + (b) +(c). It is to be noted that
these four elements are features of the group and
not the individuals comprising it, as obviously,
for a single fish, (a), (b), (c) and (d) must
always be zero. Thus these features can be con-
sidered as a new element not possessed by a soli-
tary fish and to this extent, even in these simple
associations, the whole is greater than the sum
of its parts, something has “emerged”— a society
of only very elemental features. These thoughts
are clearly an oversimplification but such mod-
els should be useful in indicating the nature of
what belongs to a fish and what to a fish group.
Although many fish aggregations superficially
appear to have nothing more than these models,
it would seem probable that, on adequate analy-
sis, other and subtle interindividual relations
could be found. Also schools in which the mem-
bers appear to be equipotential may in fact be
merely ones in which the lack of such a state is
masked because unequal potentials are balanced,
a condition difficult to detect.
Since any aggregation of fishes may obviously
be considered as a dynamic system of interacting
parts, it is possible to treat the behavior of such
a group in terms of the concept of stability.
Analysis of this concept in other fields has fre-
quently yielded valuable information covering
the manner of operation of a great variety of
diverse types of systems. See the review of Cun-
ningham (1963). For present purposes it is suf-
ficient to consider a stable system as one which,
after small disturbances, returns to its former
state, and an unstable one as a system in which
small disturbances are not followed by a return
to the former state but lead to a new one, which
could include the final destruction of the system.
Although such ideas go back at least to Liapunov
(1892), stable and unstable systems are respec-
tively systems with negative feedback and posi-
tive feedback, in the terminology of cyberneti-
cists.
Systems, such as fish schools, cannot be linear,
for if they were, the size of the disturbance
would not be important, a situation that is cer-
tainly not true in any fish aggregation, where the
magnitude of a disturbance has a distinct bearing
on the outcome. This checks with theoretical
considerations, as noted by Cunningham loc cit.
The very fact that fish groups do occur demon-
strates that they have some degree of stability
which permits them to survive some kinds of
minor disturbances and indicates the presence
of negative feedback. This quantity may vary
considerably and is often measured in a rough
way by the terms “loose” and “tight,” sometimes
applied to fish schools or other groups such as ag-
gregations, and pods. Here the coherence of the
group increases from the first to the third as the
fish pass from an aggregation to a school to a
pod of individuals in physical contact.
The above approach to fish groups emphasizes
the special nature of the fish school and bears on
the meaning of some aspects of the descriptive
equations, of Breder (1954 and 1959), which
expressed the balance between the centrifugal
and centripetal influences in the serried ranks of
the fish school. What were called centripetal in-
fluences are clearly the effects of negative feed-
back, while those called centrifugal influences
are the effects of positive feedback. It is obvious
that the first must exceed the second at any dis-
tance between the fishes greater than the stand-
ard fish-to-fish distance for the group. At the
established standard distance the positive feed-
back becomes precisely equal to the negative.
In terminology of ecologists the same thoughts
may be attained by considering a fish school
and its immediate environment as an ecosystem,
which the term clearly covers. See, for instance,
Egler (1964). Further elaboration at this point
would be redundant.
Summary
1. Since fishes produce vortices when swim-
ming which surround them and leave a trail of
dying vortices after them, it follows that these
become a factor in the environment of those
fishes accompanying them, an element that is of
special significance to the structure of the fish
school.
2. The side-to-side spacing of fishes in a school
is usually just a little over twice the distance
from the side of a fish to the outer edge of the
trail of vortices in the area of their production,
which insures their integrity until the fishes have
left them behind.
3. As the maintenance of the integrity of these
vortices is important to the efficiency of the fish’s
locomotor efforts, this may be the controlling
factor that determines how closely fishes in a
school approach each other.
4. There is usually continual shifting of posi-
tions of fish within a school which is evidently
112
Zoologica: New York Zoological Society
[50: 10
partly controlled by accidental encounters with
parts of the vortices that reduce swimming effi-
ciency. This continual adjustment by the fishes
makes possible the continued existence of the
group.
5. The range in sizes of fishes that may com-
prise a stable school appears to be limited to
something closer than 1 to 0.6, taking the largest
individual as unity.
6. Also evidently responsible for some part of
the continual shifting is the fact that the fish
are not precisely of one size, nor are they of
identical swimming ability or degree of fatigue,
which produces somewhat of a conflict between
individually preferred swimming speed and the
attempt of each fish to keep close to its group.
7. Since vortices appear in various natural
conditions from many sources, fishes make ap-
propriate adjustments to them, especially notice-
able in certain rates of flow where a stream may
be filled with a mixture of several Karman vortex
trails, forcing fishes which venture into it to take
a marked zigzag course, both avoiding adverse
flow and benefiting from advantageous flow,
from one sheltered place to another.
8. Closed figure fish schools, the so-called fish
mills, may be initiated by both extrinsic and in-
trinsic causes, the first and classic cause being
something that turns the forwardly placed mem-
bers so they see the trailing members and pro-
ceed to follow them. The second is associated
with the structure of the school involving viscous
shear and showing behavior very like that of a
viscid fluid.
9. The disruption of schools by violent means
is usually followed by immediate re-formation,
while disruption by specialized feeding methods
or special feeding techniques is followed by re-
formation only after the full completion of the
special action involved.
10. Considering the fish school as a system of
interacting parts, the relations within it cannot
be linear, for if they were, the reactions of a
school as a whole would, on a basis of response
to disturbances, be notably different.
11. Similarities and differences between the
vorticular systems found in association with
swimming fishes and the vortices found in other
situations are discussed. Included are comments
on the theoretical size limits of schools, the na-
ture of their redundancy and the elements of at-
traction and repulsion present.
Bibliography
Atz, J. W.
1953. Orientation in schooling fishes. In Pro-
ceedings of a Conference on Orientation
in Animals, Feb. 6 and 7, 1953, Washing-
ton. Washington, D. C., Office of Naval
Research, Department of the Navy, pp.
103-130.
Bainbridge, R.
1958a. The speed of swimming fish as related to
size and to the frequency of the tail beat.
Jour. Exp. Biol., 35: 109-133.
1958b. The locomotion of fish. New Scientist, 4:
476-478.
Bainbridge, R., & R. H. J. Brown
1958. An apparatus for the study of the loco-
motion of fish. Jour. Exp. Biol., 35: 134-
137.
Bergeijk, H. A. van
1964. Evolution of binaural hearing. [Abstract
A9.] Program of the 67th meeting of the
Acoustical Society of America: 8.
Birkhoff, G.
1962. Helmholtz and Taylor instability. Proc.
Symposium Applied Math., Amer. Math.
Soc.. 13: 25-33.
Breder, C. M., Jr.
1924. Respiration as a factor in locomotion of
fishes. Amer. Nat., 58: 145-155.
1925. Fishes squirting water. Bull. New York
Zool. Soc., 28 (3): 69-72.
1926. The locomotion of fishes. Zoologica, 4:
159-297.
1951. Studies on the structure of the fish school.
Bull. Amer. Mus. Nat. Hist., 98: 1-28.
1954. Equations descriptive of fish schools and
other animal aggregations. Ecology, 35
(3): 361-370.
1959. Studies on social groupings in fishes. Bull.
Amer. Mus. Nat. Hist., 117: 393-482.
Breder, C. M., Jr., & F. Halpern
1946. Innate and acquired behavior affecting
aggregations of fishes. Physiol. Zool., 19:
154-190.
Brock, V. E.
1962. On the nature of the selective fishing
action of longline gear. Pacific Science,
16 (1): 3-14.
Brock, V. E., & R. H. Riffenburgh
1960. Fish schooling: a possible factor in re-
ducing predation. Jour, du Conseil, 25
(3): 307-317.
1965]
Breder: Vortices and Fish Schools
113
Cahn, P., & E. Shaw
1963. Schooling fishes: the role of sensory fac-
tors. Animal Behaviour, 11: 2-3. [Ab-
stract.]
[MS.]. A method for studying lateral line cupu-
lar activity of juvenile fishes.
Cunningham, W. J.
1963. The concept of stability. Amer. Scientist,
51 (4): 425-436.
Egler, F. E.
1964. Pesticides— in our ecosystem. Amer. Sci-
entist, 52 (1): 110-136.
Fry, F. E. J., & J. S. Hart
1947. Cruising speed of goldfish in relation to
water temperature. Jour. Fish. Res. Board
Canada, 7 (4): 169-175.
Gadd, G. E.
1963a. Some hydrodynamical aspects of swim-
ming. Ship Rept. 45, Natl. Phys. Lab.,
Ship Div., Feltham, England: 1-26.
1963b. The hydrodynamics of swimming. New
Scientist, 19 (355): 483-485.
Hill, A. V.
1949. The dimensions of animals and their mus-
cular dynamics. Royal Institution of
Great Britain, Weekly Evening Meeting,
Nov. 4: 1-24.
John, K. R.
1964. Illumination, vision and schooling of
Astyanax mexicanus (Fillipi). Jour. Fish.
Res. Bd. Canada, 21 (6): 1453-1473.
Johnson, H. A.
1963. Redundancy and biological aging. Science,
Sept. 6, 141: 910-912.
Karman, T. von
1912. l)ber den Mechanismus des Wider-
standes den ein bewegter Korper in einer
Fllissigkeit erfahrt, Nachr. d. Wiss. Ges.
Gottingen, Math. Phys. Kl., 509 (1911)
and 547 (1912).
Keenleyside, M. H. A.
1955. Some aspects of the schooling behaviour
of fish. Behaviour, 8 (2-3): 183-248.
Liapunov, M. A.
1892. In Russian. Karkov. Probleme general de
la stabilite du mouvement. Annales de
Toulouse, 9 (2): 203-474, 1907. Prince-
ton University Press 1949, Ann. Math.
Study No. 17.
Malkus, J. S.
1963. Cloud patterns over tropical oceans. Sci-
ence, Aug. 30, 141: 767-778.
Matschinski, M.
1953. La mecanique de la nage chez les poissons.
Bull. Fran^ais Piscicult., no. 171: 45-73.
Miyadi, D.
1958. Perspectives of experimental research on
social interference among fishes. In Buz-
zati-Tra verso, A. A. (ed.), Perspectives in
marine biology. Berkeley, University of
California Press: 469-479.
Moulton, J. M.
1958. The acoustical behavior of some fishes in
the Bimini area. Biol. Bull., 114 (3) : 357-
374.
Nagel, E.
1963. Wholes, sums and organic unities. In
Lerner, D. (ed.), Parts and wholes. Glen-
coe, New York, The Free Press: 135-155.
Ohshima, Y.
1950. An experiment on the shoaling behaviour
in fish: The case when two homotypic
shoals consisting of large and small indi-
viduals met with each other. Bull. Jap-
anese Soc. Sci. Fish., 16 (5): 195-200.
Okuno, R.
1962. Distribution of young of two reef fishes,
Girella punctata Gray and G. melanich-
thys (Richardson), in Tanabe Bay and
the relationship found between their
schooling behaviors. Pubis. Seto Marine
Biol. Lab., Kobe, Japan, 10 (2) : 293-306.
1963. Observations and discussions on the so-
cial behaviors of marine fishes. Ibid., 1 1
(2): 281-336.
Olson, F. C. W.
1964. The survival value of fish schooling. Jour,
du Conseil, 29 (1): 115-116.
Parr, A. E.
1927. A contribution to the theoretical analysis
of the schooling behavior of fishes. Occas.
Papers Bingham Oceanogr. Coll., no. 1 :
1-32.
Prandtl, L.
1904. Uber Flussigkeitsbewegung bei sehr
kleiner Reibung. Verhandlungen des III
Internat. Math.-Kongresses, Heidelberg:
484-491.
Purcell, E.
1963. Parts and wholes in physics. In Lerner,
D. (ed.). Parts and wholes. Glencoe, New
York, The Free Press: 11-39.
Rosen, M. W.
1959. Water flow about a swimming fish. Station
Tech. Publ. U. S. Naval Ordnance Test
Station, China Lake, California, NOTS
TP 2298: i-v, 1-94.
Rouse, H.
1946. Elementary mechanics of fluids. New
York, John Wiley & Sons, Inc.: i-xii, 1-
376.
114
Zoologica: New York Zoological Society
[50: 10: 1965]
1963. On the role of eddies in fluid motion.
Amer. Scientist, 51 (3): 285-314.
Schaefer, M. B.
1948. Size composition of catches of yellowfin
tuna (Neothunnus macropterus) from
Central America and their significance in
the determination of growth, age and
schooling habits. Fish. Bull. Fish & Wild-
life Serv., 51 (44): 197-200.
Schafer, W.
1955. Uber das Verhalten von Jungerherings-
schwarmen im Aquarium. Arch. f. Fisch-
ereiwiss., yr. 6 (5/6): 276-278.
SCHLICHTING, H.
1951. Boundary layer theory. Fourth ed. Eng-
lish. Dr. J. Kestin translator. 1960, New
York, McGraw-Hill Book Co., i-xx, 1-
647.
Sette, O.
1950. Biology of the Atlantic mackerel (Scom-
ber scombrus) of North America. Part II.
Migrations and habits. Fish. Bull. Fish &
Wildlife Serv., 51 (49): 251-358.
Shaw, E.
1958a. A study of current orientation as a stimu-
lus to schooling behavior in Menidia.
[Abstract.] Biol. Bull., 113 (2): 354-355.
1958b. A study of visual attraction as a stimu-
lus to schooling behavior in Menidia.
[Abstract.] Ibid., 115 (2): 365.
1961. Minimal light intensity and the dispersal
of schooling fish. Bull. Inst. Oceanogr.
Monaco, no. 1213: 1-8.
Shaw, E., & A. Tucker
[In Press], The optomotor response of schooling
carangid fishes. Animal Behaviour.
Shaw, W. C.
1959. Sea animals and torpedoes. Navord Rept.
6573, Tech. Publ. U.S. Naval Ordnance
Test Station, China Lake, California,
NOTS TP 2299: i-vii, 1-44.
Shuleikin, V. V.
1958. How the pilot fish moves with the speed
of the shark. Doklady Akad. Nauk
S.S.S.R. Transl. Biol. Sci. Sect., 119
(1/6): 140-143.
Townsend, C. H.
1909. Water-throwing habit of fishes in the New
York Aquarium. Bull. New York Zool.
Soc., no. 33: 488.
Verheijen, F. J.
1953. Laboratory experiments with the herring,
Clupea harengus. Experientia, 9, fasc. 5:
193-194.
1956. Transmission of a flight reaction amongst
a school of fish and the underlying sen-
sory mechanism. Ibid., 12, fasc. 5: 202-
204.
Walters, V.
1962. Body form and swimming performance
in the scombroid fishes. Amer. Zool., 2
(2): 143-149.
EXPLANATION OF THE PLATES
Plate I. Goldfish in a suspension of bentonite,
showing flow lines. Courtesy of the
Goodyear Aircraft Corp.
Plate II. A school of Thunnus thynnus viewed
from the air. Courtesy of Mr. George A.
Bass.
Plate III. Upper: An “exploding” school of Mugil
cephalus, startled by a passing kingfisher.
Lower: A tight school of Mugil cephalus
under which condition there is little for-
ward translation, except at the upper
margin, which shows loosening with in-
creased forward movement.
Plate IV. Stages in mill formation within a school
of Mugil cephalus, showing the “viscous
shear” type of origin. The position of the
school in the successive stages is indi-
cated by the wisp of grass on the shore
showing in the lower right-hand margin.
The two time intervals between the three
photographs are about equal, at approxi-
mately eight seconds.
NIGRELL1 a RUGGIERI
PLATE I
FIG. 3
FIG. 4
STUDIES ON VIRUS DISEASES OF FISHES. SPONTANEOUS AND EXPERIMENTALLY-INDUCED CELLULAR
HYPERTROPHY (LYMPHOCYSTIS DISEASE) IN FISHES OF THE NEW YORK AQUARIUM. WITH A
REPORT OF NEW CASES AND AN ANNOTATED BIBLIOGRAPHY (1874-1965)
NIGRELLI a RUGGIERI
PLATE II
FIG. 5
FIG. 6
STUDIES ON VIRUS DISEASES OF FISHES. SPONTANEOUS AND EXPERI MENTALLY- 1 N DUCED CELLULAR
HYPERTROPHY (LY M PHOCYSTIS DISEASE) IN FISHES OF THE NEW YORK AQUARIUM, WITH A
REPORT OF NEW CASES AND AN ANNOTATED BIBLIOGRAPHY (1874-1965)
NIGRELLI & RUGGIERI
PLATE III
FIG 8
FIG. 7
STUDIES ON VIRUS DISEASES OF FISHES. SPONTANEOUS AND EXPERIMENTALLY-INDUCED CELLULAR
HYPERTROPHY (LYMPHOCYSTIS DISEASE) IN FISHES OF THE NEW YORK AQUARIUM, WITH A
REPORT OF NEW CASES AND AN ANNOTATED BIBLIOGRAPHY (1874-1965)
NiGRELLI & RUGGIERI
PLATE IV
FIG. 9
FIG. 10
FIG. 11
STUDIES ON VIRUS DISEASES OF FISHES. SPONTANEOUS AND EXPERIMENTALLY-INDUCED CELLULAR
HYPERTROPHY (LYMPHOCYSTIS DISEASE) IN FISHES OF THE NEW YORK AQUARIUM. WITH A
REPORT OF NEW CASES AND AN ANNOTATED BIBLIOGRAPHY (1874-1965)
NIGRELLI 8 RUGGIERI
PLATE V
FIG. 12
FIG. 14
STUDIES ON VIRUS DISEASES OF FISHES. SPONTANEOUS AND EXPERIMENTALLY-INDUCED CELLULAR
HYPERTROPHY (LYMPHOCYSTIS DISEASE) IN FISHES OF THE NEW YORK AQUARIUM, WITH A
REPORT OF NEW CASES AND AN ANNOTATED BIBLIOGRAPHY (1874-1965)
NIGRELLI a RUGGIERI
PLATE VI
FIG. 15
FIG 16
STUDIES ON VIRUS DISEASES OF FISHES. SPONTANEOUS AND EXPERIMENTALLY-INDUCED CELLULAR
HYPERTROPHY (LYMPHOCYSTIS DISEASE) IN FISHES OF THE NEW YORK AQUARIUM. WITH A
REPORT OF NEW CASES AND AN ANNOTATED BIBLIOGRAPHY (1874-1965)
NIGRELLI & RUGGIERI
PLATE VII
FIG. 17
FIG. 18
STUDIES ON VIRUS DISEASES OF FISHES. SPONTANEOUS AND EXPERI MENTALLY- 1 N DUCED CELLULAR
HYPERTROPHY (LYMPHOCYSTIS DISEASE) IN FISHES OF THE NEW YORK AQUARIUM. WITH A
REPORT OF NEW CASES AND AN ANNOTATED BIBLIOGRAPHY (1874-1965)
NIGRELLI & RUGGIERI
PLATE VIII
FIG. 19
FIG. 21
STUDIES ON VIRUS DISEASES OF FISHES. SPONTANEOUS AND EXPERIMENTALLY-INDUCED CELLULAR
HYPERTROPHY (LY M PHOC YSTIS DISEASE) IN FISHES OF THE NEW YORK AQUARIUM. WITH A
REPORT OF NEW CASES AND AN ANNOTATED BIBLIOGRAPHY (1874-1965)
NIGRELLI & RUGGIERI
PLATE IX
FIG. 22
FIG. 23
FIG. 24
STUDIES ON VIRUS DISEASES OF FISHES. SPONTANEOUS AND EX PER I MENTALLY-I N DUCED CELLULAR
HYPERTROPHY (LY MPHOCYSTIS DISEASE) IN FISHES OF THE NEW YORK AQUARIUM. WITH A
REPORT OF NEW CASES AND AN ANNOTATED BIBLIOGRAPHY (1874-1965)
NIGRELLI & RUGGIERI
PLATE X
FIG. 25
FIG. 26
STUDIES ON VIRUS DISEASES OF FISHES. SPONTANEOUS AND EX PER I MENTALLY-I NDUCED CELLULAR
HYPERTROPHY (LYMPHOCYSTIS DISEASE) IN FISHES OF THE NEW YORK AQUARIUM, WITH A
REPORT OF NEW CASES AND AN ANNOTATED BIBLIOGRAPHY (1874-1965)
BREDER
PLATE I
VORTICES AND FISH SCHOOLS
BREDER
PLATE II
VORTICES AND FISH SCHOOLS
BREDER
PLATE III
VORTICES AND FISH SCHOOLS
BREDER
PLATE IV
VORTICES AND FISH SCHOOLS
ZOOLOGICA
SCIENTIFIC CONTRIBUTIONS OF THE
NEW YORK ZOOLOGICAL SOCIETY
VOLUME 50 • ISSUE 3 • FALL, 1965
PUBLISHED BY THE SOCIETY
The ZOOLOGICAL PARK, New York
Contents
PAGE
1 1 . Studies on Virus Diseases of Fishes. Epizootiology of Epithelial Tumors in
the Skin of Flatfishes of the Pacific Coast, with Special Reference to the
Sand Sole (Psettichthys melanosticus) from Northern Hecate Strait, British
Columbia, Canada. By Ross F. Nigrelli, K. S. Ketchen & G. D. Rug-
gieri, S. J. Plates I-XI; Text-figures 1&2 115
12. Waving Display and Sound Production in the Courtship Behavior of Uca
pugilator, with Comparisons to U. minax and U. pugnax. By Michael
Salmon. Plates I-V ; Text-figures 1-7 123
1 3. Genetics and Geography of Sex Determination in the Poeciliid Fish, Xipho-
phorus maculatus. By Klaus D. Kallman. Text-figure 1 151
Zoologica is published quarterly by the New York Zoological Society at the New York
Zoological Park, Bronx Park, Bronx, N. Y. 10460, and manuscripts, subscriptions, orders for back
issues and changes of address should be sent to that address. Subscription rates: $6.00 per year;
single numbers, $1.50, unless otherwise stated in the Society’s catalog of publications. Second-class
postage paid at Bronx, N. Y.
Published November 10, 1965
11
Studies on Virus Diseases of Fishes. Epizootiology of Epithelial Tumors
in the Skin of Flatfishes of the Pacific Coast, with Special Reference to
the Sand Sole (Psettichthys melanosticus) from Northern Hecate Strait,
British Columbia, Canada
Ross F. Nigrelli,1 K. S. Ketchen2 & G. D. Ruggieri, S. J.1
( Plates I-XI; Text-figures 1 & 2)
Introduction
SOLITARY or multiple epithelial tumors
described as cutaneous warts, papillomas
and hyperplastic epidermal diseases, and
for which a viral etiology has been suggested
or implied, have been reported in several species
of European and North American flatfishes
(Order: Pleuronectiformes, or Heterosomata)
(Table 1). The early reports deal with isolated
incidences while the more recent publications
are concerned with epizootics involving hun-
dreds of individuals in flatfish populations in the
following three general areas of the Pacific
coast of North America: (1) sand soles from
British Columbia (Ketchen, 1953); (2) lemon
and flathead soles from Washington (Pacis,
1932; Good, 1940; Chuinard, et al, 1964); and
(3) lemon and Dover soles from southern Cali-
fornia (Herald & Innes, pers. comm.; Young,
1964).
The present paper deals with the epizootiology
of the disease causing epithelial tumors in sand
soles from British Columbia, and includes the
histopathology of the tumors in this species and
in rock soles from the same area.
Description of the Tumors
Tumors from formalin-fixed specimens of
sand and rock soles were sectioned at 4 microns
and stained with the following: Harris’s hema-
toxylin-eosin; Heidenhain’s iron-hematoxylin
with and without eosin; Masson’s triple stain;
Giemsa’s stain; Heidenhain’s “Azan” variant;
Mayer’s mucicarmine; and PAS. Formalin-fixed
1New York Aquarium, Coney Island, N.Y. 11224.
fisheries Research Board of Canada, Ottawa.
tissue was also treated with osmium tetroxide
(2% sol.; vapor method) and in some instances
followed with Heidenhain’s iron-hematoxylin.
Macroscopically, the epithelial growths in the
sand sole are found in the skin of relatively
young fish (1-3 years old), usually less than
20 cm. in length (Table 2, Text-fig. 2). The
lesions appear as solitary or multiple, flat or
raised, grayish or brownish growths of various
dimensions. They occur on both sides of the fish
but more frequently on the pigmented or eyed
side of the body, usually adjacent to and often
associated with the rays of the fins (PI. figs. 1
& 2). In some cases, the tumors are also found
in the head region, occasionally involving the
limbus corneae and the operculum. Epithelial
tumors in the rock and lemon sole are shown
for comparison with the sand sole in PI. figs. 3
& 4. The tumor in the lemon sole (PI. fig. 4)
appears to be a papilloma, the pathology of
which will be described at a later date.
Microscopically, the lesions vary from a sim-
ple to an extensive hyperlasia of the epithelium,
with a papillary-like structure present in some
areas (PI. figs. 7-11, 15, 19, 22). However,
the over-all appearance of the growths is sug-
gestive of a regressive process. No mitotic fig-
ures were seen and the staining reaction, in
general, was weak, with some evidence of in-
flammatory responses and necrotic changes.
The epithelium in “normal” areas of the skin
consists of stratified cells, interspersed with
mucous cells (PI. fig. 5). In an area that rep-
resents a transitional region between “normal”
and hyperplastic epithelium (PI. fig. 6), en-
larged epithelial cells characteristic of the main
115
116
Zoologica: New York Zoological Society
[50: 11
Table 1. Epithelial Tumors in the Skin of Flatfishes (Pleuronectiformes, or Heterosomata)
Species
No. Fish
Reported
Common Name
Locality
Author
Hippoglossus hippoglossus
1
Halibut
North Sea
Johnstone, 1912
Pleuronectes platessa
2
Plaice
North Sea
Johnstone, 1925
Pleuronectes (Limanda) limanda
3
Dab
North Sea
Johnstone, 1925
Solea solea
2
Sole
North Sea
Thomas, 1930
Pseudopleuronectes americanus
2
Winter Flounder
L. I. Sound
Smith, 1935
Parophrys vetidus
Epizootic
Lemon or English
Sole
Washington,
California
Pacis, 1932; Good,
1940; Wellings,
et ah, 1965;
Herald & Innes,
MS
Psettichthys melanosticus
Epizootic
Sand Sole
B.C., Canada,
Washington
Ketchen, 1953;
present paper;
Wellings, et al.,
1965
Lepidopsetta bilineata
5
Rock Sole
B. C., Canada
Ketchen, 1953;
present paper
Hippoglossoides elassodon
Epizootic
Flathead Sole
Washington
Wellings, et ah,
1963, 1964, 1965;
Chuinard, et ah,
1964
Glyptocephalus zachirus
3
Rex Sole
Washington
Chuinard, et al,
1964; Wellings,
et ah, 1965
Microstomas pacificus
Epizootic
Dover Sole
California
Young, 1964
part of the growth are present (PI. figs. 12-14).
These elements are PAS-negative.
The hyperplastic epithelium is supported by
a stroma of collagenous fibers and vascular ele-
ments in which melanin-bearing cells are fre-
quently present (PI. figs. 7-9). Mucous cells,
when present, are usually arranged at the peri-
phery of the growth, or sometimes clustered
just below the surface (PI. figs. 10 & 11).
Sloughing and necrosis of the epithelium is
evident in some parts of the tumor. The char-
acteristic elements of the tumors are “swollen”
epithelial cells, measuring from 15 to 20 microns
or about 2 to 3 times the size of the normal cell.
These cells have weakly-staining nuclei and
vacuolated cytoplasm containing osmiophilic or
basophilic granular or filamentous inclusions
(PI. figs. 12-14).
The corium associated with the growths in
the sand sole is usually only slightly thickened or
edematous (PI. figs. 7 & 8). Extreme changes,
when present, are apparently related to encysted
worm parasites (PI. figs. 15 & 16). The reac-
tions are manifested principally by inflamma-
tory responses and by the development of an ex-
tensive, proliferative, angiomatous-like tissue
(PI. figs. 17-19) that extends into the support-
ing stroma of the hyperplastic epithelium and
into the deeper tissues through the intermus-
cular pathways, causing destruction of the sur-
rounding tissues (PI. fig. 20). In addition, peri-
arteritis, angititis and other sclerosing changes
of blood vessels, as well as an extensive and
striking lymphangiectasis of the cutaneous and
sub-muscular lymph vessels, are frequently as-
sociated with the lesions (PI. figs. 21-23).
Distribution and Incidence in Sand Soles
The high incidence of epithelial tumors in
juvenile sand soles were found in certain stations
along the east coast of Graham Island, British
Columbia (Text-fig. 1).
Most of the fish affected were 1 to 3 com-
pleted years in age. The group measuring from
5 to 17 cm. (mode 10 cm.) consisted of age 1
and 2 fish and the second group from 18 to 26
cm. (mode 22 cm.) consisted mainly of age
3 fish. (Table 3). No individuals of the 0-age
group were present in our samples, suggesting,
in contrast to other flatfishes, that the growth
of the sand sole in the juvenile stages is rather
slow.
As noted in Table 2, the incidence of the
lesions increased steadily from north to south,
being less than 10% in fish caught adjacent to
Rose Spit and over 40% in those caught near
Cape Ball (Stations X and XI, Text-fig. 1).
All these stations were inside the 5-fathom con-
1965]
Nigrelli, Ketchen & Ruggieri: Studies on Virus Diseases of Fishes
117
Text-fig. 1. Trawling stations along the eastern shore of Graham Island in Hecate Strait, British
Columbia.
tour. In 12 drags made in a section across the
deeper part of the bank between the depths of
13 and 18 fathoms, 153 sand soles were col-
lected but none showed signs of the tumor.
Text-fig. 2 is a composite graph of all fish taken
along the east coast of the island and clearly
shows the relationships between incidence and
size of fish. The absence of lesions in fish taken
in the drags across the bank in deeper water
may be explained by the fact that these fish were
118
Zoologica: New York Zoological Society
[50: 11
Table 2. Record of Sand Sole Catches from Shallow-water Sampling Stations along
the East Coast of Graham Island, with Information on Tumor Incidence
Station
No. of
Drags1
Numbers of fish
Tumorous
Percent.
Diseased
Caught
Measured
Examined for
Tumors
I
2
26
26
24
2
8.3
II
2
72
72
26
2
7.7
III
6
337
321
44
7
15.9
IV
2
118
118
45
7
15.5
V
5
117
117
36
5
13.9
VI
2
106
106
26
5
19.2
VII
1
45
45
VIII
2
307
223
115
28
24.4
IX
2
107
107
64
27
42.2
X
3
183
183
143
62
43.4
XI
3
208
208
206
86
41.7
Total
30
1626
1526
729
231
31.7%
1A11 drags were of 20 minutes duration, using a small-meshed “shrimp-trawl.” Foot rope length: 36 ft.; cod-end
mesh size: 1 in. between diagonal knots.
on the average several centimeters larger than
those taken along the east coast of Graham
Island. The highest incidence was found in the
vicinity of Cape Ball where the fish were smaller
than those sampled in other areas.
Epithelial tumors were also found occasion-
ally in juvenile rock soles (Lepidopsetta bilin-
eata) but none were seen in young butter (Isop-
setta isolepis) or in lemon (Parophrys vet ulus)
soles of the same area.
Discussion
Although papillomas have been reported in
flatfishes (Johnstone, 1912, 1925; Thomas, 1930;
Wellings, et al, 1963; Chuinard, et al, 1964),
the growths in the sand and rock soles from
British Columbia in our collection are inter-
preted as a hyperplastic epidermal disease in
which the development of the epithelium may
become extensive, sometimes bordering on a
papillomatous structure. This suggests that the
hyperplasia may represent a pre-neoplastic
state. A striking feature in some of the tumors
of the sand and rock soles is the development of
lymphangiectasis and a proliferative angiomat-
ous-like growth. The inter-relationships of these
with each other, with the presence of encysted
worm parasites to which these fish are highly
susceptible and with the development of the
epithelial hyperplasia, are not evident at pres-
ent. The need for further investigation is indi-
cated by the fact that in mammals angiomatosis
and lymphangiectasis are often inter-related,
congenital or hereditary in origin, and usually
occur in young animals or persons.
The epizootic nature of the epithelial tumors
in several species of flatfishes from the Pacific
coast, the presence of osmiophilic and basophilic
inclusions reported here in the “swollen” epi-
thelial cells in the sand and rock soles and in
the California English sole by Dr. Richard
Skahen (Herald & Innes, pers. comm.), and the
virus-like bodies demonstrated in the flathead
soles by electron-microscopy (Wellings & Chui-
nard, 1964; Wellings et al, 1965), strongly indi-
cate an infectious process of viral etiology. The
inclusions noted in the present studies are sug-
gestive of the cytomegaloviruses, and remi-
niscent of the cytoplasmic inclusions seen in the
cellular hypertrophy disease (lymphocystis tu-
mors) in European flounders (Weissenberg,
1960), other fishes (Nigrelli & Ruggieri, 1965),
and also of those seen in several of the pox and
other viral diseases of higher vertebrates (Love,
1959).
The widespread distribution and high inci-
dence of epithelial tumors in flatfishes of the
Pacific coastal areas is of considerable economic
and biological importance. Apparently, the
tumors in fishes of this area were first noted in
1922 by Dr. Carl Hubbs (Scripps Oceanograph-
ic Institution, La Jolla) who wrote that he was
concerned with the “wart-like dermal swellings”
in Parophrys in San Francisco Bay and with the
possibility that the disease may be correlated
with pollution (field notes quoted by Herald &
Innes, pers. comm). A survey made in 1951-
1953 under the direction of Dr. Herald showed
that the disease still existed in San Francisco
Bay with an incidence ranging from 16% to
32% in English soles (Parophrys vetulus) caught
in north bay trawls; a single sample from a
south bay “Chinese” shrimp-net catch showed
a 6% incidence. No fish less than 50 mm. in
length appeared to be affected.
1965]
Nigrelli, Ketchen & Ruggieri: Studies on Virus Diseases of Fishes
119
Text-fig. 2. Length-frequency distributions of infected and non-infected sand soles taken at the stations
along the east coast of Graham Island.
The epithelial growth in Parophrys vetulus,
commonly called the English sole in California
and Washington and the lemon sole in British
Columbia, was studied earlier by Pacis (1932)
and by Good ( 1940). Both of these workers re-
ported lower incidence than in California in
fish taken from several beaches at low tide in
and around Seattle. Pacis (1932) showed an
average incidence of 4.8%, with the tumors
occurring most frequently in soles measuring be-
tween 9 cm. and 20 cm.; most (73.6%) were
in their second year of growth. Good (1940)
repeated the studies on English soles from other
beaches of Seattle and obtained slightly higher
values (4.7% to 10%), and also showed an
apparent seasonal distribution, with the highest
incidence occurring in November and Decem-
ber. No diseased fish were found in April and
May. Further, he also found that soles under
50 mm. in length (1st year of life) were free of
the tumors. Starry flounders (Platichthys stel-
latus ) and rock soles (Lepidopsetta bilineata )
collected at the same time were free of the
disease.
Tumors, described as epidermal papillomas,
were reported recently in flathead soles, Hippo-
glossoides elassodon , from San Juan Islands and
Orcas Island, near Friday Harbor, Washington
120
Zoologica: New York Zoological Society
[50: 11
Table 3. Incidence of Tumors in Sand Sole,
by Size
Size
Group
cm.
Numbers of Fish
Tumorous
Non-
tumorous
Total
5
1
1
6
1
1
7
6
2
8
8
28
20
48
9
63
59
122
10
49
106
155
11
30
91
121
12
22
73
95
13
19
43
62
14
4
18
22
15
2
18
20
16
4
12
16
17
1
3
4
18
2
2
19
6
6
20
1
5
6
21
2
2
22
9
9
23
3
3
24
3
3
25
4
4
26
2
2
27
1
1
28
1
1
29
1
1
30
2
2
31
2
2
32
2
2
33
3
3
34
35
1
1
36
37
38
1
1
Total
231
495
726
(Wellings, et al, 1963; Chuinard, et al, 1964).
The disease was also found occasionally in rock
soles and rex soles (Glyptocephalus zachirus)
from the same area. The incidence in the flat-
head sole was 5.1% and tumors were found
most frequently in the 0-age group.
In northern British Columbia, the tumors are
apparently absent from both juvenile and adult
lemon (English) soles and butter soles (Isopsetta
isolepis), but they occur occasionally in the rock
sole. In Hecate Strait, for the past 5 years, the
average annual Canadian landings of each spe-
cies of sole have been as follows: 1.6 million
lbs. (rock sole); 1.2 million lbs. (lemon sole);
95,000 lbs. (butter sole) ; 2,000 lbs. (sand sole) .
The lemon sole is the preferred species. In
earlier years catches of lemon sole and rock
sole occasionally have exceeded 5 million lbs.
and catches of butter sole have reached about
4 million lbs. (see also, Ketchen, 1956). The
sand sole rarely appears in landings in “pure
culture.” It is so uncommon, at least in Hecate
Strait, that by the time it reaches commercial
size it is only incidental in landings of other
species. It grows to a maximum size of 63 cm.,
but average size in landings is not much more
than 40 cm.
This suggests that the young sand sole is
subject to a high natural mortality as a result
of the disease3. However, since the pathological
evidence indicates that it is a regressive disease,
other possible ecological factors may be respon-
sible for what appears to be a reduction of the
adult population of sand soles. The diseased
fish may be at a disadvantage in competition for
food or they may be more susceptible to preda-
tion and to abnormal environmental factors. It
is quite evident that brood stocks of sand soles
are present at all times to sustain a relatively
large annual population of at least young fish.
Whether or not the susceptible species (lemon
or English, flathead, rock, rex, sand and Dover
soles) from other areas of the Pacific coast of
North America are also subject to an apparent
high natural mortality, directly or indirectly re-
lated to the epizootics, has not been determined.
Summary
Epizootics in young ( 1-2 year old) sand soles,
Psettichthys melanosticus, in Hecate Strait,
British Columbia, are characterized by the de-
velopment of a hyperplastic epidermal disease
of the skin, which in some instances is associated
with lymphangiectasis and an extensive angio-
matous-like proliferative lesion. The epizootio-
logical picture suggests an infectious process,
and the cytological evidence indicates that a
cytomegalovirus may be the cause.
In British Columbia, the lesions are also found
occasionally in the rock sole (Lepidopsetta bi-
lineata) but not in the lemon sole (Parophrys
vetulus) or the butter sole ( Isopsetta isolepis).
All occur in the same general area as the dis-
eased sand soles.
Similar epizootics have been reported in the
lemon sole and flathead sole (Hippoglossoides
elassodon) from Washington, lemon sole from
San Francisco Bay and in the Dover sole (Micro-
stomus pacificus ) from Santa Monica Bay, Cali-
3To some extent the low incidence of sand sole in
commercial landings may be attributed to the limited
amount of fishing in depths less than 18 fathoms. How-
ever, research vessel exploration of these depths have
failed to reveal more than scattered occurrence.
1965]
Nigrelli, Ketchen & Ruggieri: Studies on Virus Diseases of Fishes
121
i'ornia. Epithelial tumors have also been reported
occasionally in the rex sole (Glyptocephalus
zachirus) and rock sole from Washington.
It is suggested that the epizootics may be a
contributing cause of the high natural mortality
in the sand sole in Hecate Strait, British Col-
umbia.
References
Chuinard, R. G., S. R. Wellings, H. A. Bern &
R. Nishioka
1964. Epidermal papillomas in pleuronectid
fishes from the San Juan Islands, Wash-
ington. Federation Proceedings, 23: 337.
Good, Harold V.
1940. A study of an epithelial tumor of Paro-
phrys vetulus. M.S. Thesis, University of
Washington, 98 pp., 35 figs.
Herald, Earl S., & Kenneth F. Innes
MS. The shrimp and associated organisms of
San Francisco Bay. 4. English sole, Paro-
phrys vetulus. Manuscript, pp. 4 & 4A-4C,
1 fig.
Johnstone, Jas.
1912. Internal parasites and diseased conditions
of fishes. Report for 1911, Lancashire Sea-
Fisheries Lab., No. XX: 33-74.
1925. Malignant tumours in fishes. Report for
1924, Lancashire Sea-Fisheries Lab., No.
XXXIII: 105-136.
Ketchen, K. S.
1953. Tumorous infection in sand soles of North-
ern Hecate Strait (British Columbia). Re-
port on the survey of Hecate Strait in
July, 1953. Manuscript, 3 pp. & 2 figs.
1956. Factors influencing the survival of the
lemon sole (Parophrys vetulus ) in Hecate
Strait, British Columbia. J. Fish. Res. Bd.,
Canada, 13: 647-694.
Love, Robert (Conference Chairman)
1959. The cytopathology of virus infection. An-
nals N.Y. Acad., Sci„ 81: 1-214.
Nigrelli, Ross F„ & George D. Ruggieri, S. J.
1965. Studies on virus diseases of fishes. Spon-
taneous and experimentally induced cell-
ular hypertrophy (lymphocystis disease)
in fishes of the New York Aquarium, with
a report of new cases and an annotated
bibliography (1874-1965). Zoologica, 50:
83-96!"
Pacis, Marcelo R.
1932. An epithelial tumor of Parophrys vetulus.
M. S. Thesis, University of Washington, 94
pp., 24 figs.
Smith, G. M.
1935. A hyperplastic epidermal disease in the
winter flounder infected with Cryptocotyle
lingua (Creplin). Amer. J. Cancer, 25:
108-112.
Thomas, L.
1930. Contribution a l’etude des lesions precan-
cereuses chez les poissons. Les papillomes
cutanees de la sole. Bull. Assoc. Frang. p.
l’etude Cancer, 19: 91-97.
Weissenberg, Richard
1960. Some remarkable osmiophilic structures
of the inclusion bodies in the lymphocystis
virus disease of the European flounder.
Archiv. f. die Gesamte Virusforschung,
10: 253-266.
Wellings, S. R., Howard A. Bern, Richard S.
Nishioka & J. W. Graham
1963. Epidermal papillomas in the flathead sole
Proc. Amer. Assoc. Cancer Res., 4: 71.
Wellings, S. R., & R. G. Chuinard
1964. Epidermal papillomas with virus-like par-
ticles in flathead sole, Hippoglossoides elas-
sodon. Science, 146: 932-933.
Wellings, S. R., R. G. Chuinard & M. Bens
1965. A comparative study of skin neoplasms in
four species of pleuronectid fishes. Ann.
N. Y. Acad. Sci., 126: 479-501.
Wellings, S. R., R. G. Chuinard, R. T. Gourley
& R. A. Cooper
1964. Epidermal papillomas in the flathead sole,
Hippoglossoides elassodon, with notes on
the occurrence of similar neoplasms in
other pleuronectids. J. Nat. Cancer Inst.,
33: 991-1004.
Young, Parke H.
1964. Some effects of sewer effluent on marine
life. California Fish & Game, 50: 33-41.
122
Zoologica: New York Zoological Society
[50: 11: 1965]
v
EXPLANATION OF THE PLATES
Plate I
Fig. 1. Epithelial tumors on pigmented side of the
sand sole, Psettichthys melanosticus, from
Hecate Strait, British Columbia. Fish
measured 8.7 cm. About 2 X-
Fig. 2. Flat, non-pigmented lesion on the eyeless
side of another sole measuring 11.9 cm.
1.5 X.
Fig. 3. Slightly raised tumor mass on rock sole,
Lepidopsetta bilineata, from Hecate Strait.
About 3.5 X-
Plate II
Fig. 4. Cauliflower-like tumor mass on the pig-
mented side of English sole (Parophrys
vetulus) from San Francisco Bay, Cali-
fornia. Courtesy Dr. Earl Herald & De-
partment of Ichthyology, California Acad-
emy of Sciences. Slightly larger than 2 X-
Fig. 5. Section of normal skin of a sand sole,
showing the arrangement of the mucous
cells. PAS. 300 X-
Plate III
Fig. 6. Section through a transitional area of the
skin of the sand sole, showing normal
epithelium and enlarged “swollen” epithel-
ial cells characteristic of the hyperplastic
area. Hematoxylin-eosin. 1350 X-
Fig. 7. Section through fin area of the tumor
growth in the sand sole, showing normal
and hyperplastic regions of the epidermis.
Hematoxylin-eosin. 150 X-
Plate IV
Fig. 8. Area of the tumor of the sand sole, show-
ing an excessive development of the epi-
thelium but paucity of corial tissue. Note
papillary arrangement, suggesting a pap-
illomatous-like structure. Azan. 52 X-
Fig. 9. Hyperplastic epithelium in sand sole,
showing melanin-bearing cells in support-
ing stroma. Giemsa. 150 X-
Plate V
Fig. 10. Hyperplastic epithelium in sand sole, show-
ing distribution of mucous elements in the
peripheral zone. PAS. 150 X-
Fig. 11. Clusters of mucous cells in the deeper
layers of the hyperplastic epithelium in
rock sole. PAS. 300 X-
Plate VI
Fig. 12. Details of “swollen” epithelial cells char-
acteristic of the tumors in sand sole. No
mitotic figures were seen; the nucleus is
weakly staining, the nucleolus slightly
swollen and cytoplasm vacuolated. Note
granular inclusions. Heidenhain’s hema-
toxylin. 1350 X-
Fig. 13. Higher magnification of another area,
demonstrating the cytoplasmic inclusions
shown in Fig. 12. Heidenhain’s hematoxy-
lin. 2500 X-
Plate VII
Fig. 14. Similar cells in rock sole. The central cell
shows filamentous inclusions. Heidenhain’s
hematoxylin. 1350 X-
Fig. 15. Corial region of the tumor, showing. en-
cysted worm parasites in sand sole. Azan.
150 X-
Plate VIII
Fig. 16. Another area of the same fish with en-
cysted metacercaria (Echinostome). Note
development of connective tissue. Hema-
toxylin-eosin. 600 X-
Fig. 17. Angiomatous-like reaction in sand sole
infected with the parasites. Hematoxylin-
eosin. 600 X-
Plate IX
Fig. 18. Similar reaction associated with the epi-
thelial hyperplasia in the rock sole. Hem-
atoxylin-eosin. 300 X-
Fig. 19. Section of tumor in sand sole, showing the
relation of the angiomatous-like tissue to
the supporting stroma of the epithelial
hyperplasia. Hematoxylin-eosin. 300 X-
Plate X
Fig. 20. Proliferation of the angiomatous-like tissue
shown in Fig. 17 into intermuscular path-
ways. Hematoxylin-eosin. 150 X-
Fig. 21. Periarteritis in another area of the same
section shown in Fig. 20. Hematoxylin-
eosin. 600 X-
Plate XI
Fig. 22. Lymphangiectasis in corial region associ-
ated with the epithelial hyperplasia in the
rock sole. Hematoxylin-eosin. 150 X-
Fig. 23. Lymphangiectasis in submuscular area of
sand sole with hyperplastic epithelium and
angiomatous-like proliferative tissue shown
in Fig. 17. Hematoxylin-eosin. 600 X-
NIGRELLI, KETCHEN & RUGGIERI
PLATE I
STUDIES ON VIRUS DISEASES OF FISHES. EPIZOOTIOLOGY OF EPITHELIAL TUMORS IN THE SKIN OF
FLATFISHES OF THE PACIFIC COAST, WITH SPECIAL REFERENCE TO THE SAND SOLE ( PSETTICHTHYS
MELANOSTICUS) FROM NORTHERN HECATE STRAIT, BRITISH COLUMBIA, CANADA
NIGRELLI, KETCHEN 8c RUGGIER!
PLATE II
FIG. 4
FIG. 5
STUDIES ON VIRUS DISEASES OF FISHES. EPIZOOTIOLOGY OF EPITHELIAL TUMORS IN THE SKIN OF
FLATFISHES OF THE PACIFIC COAST, WITH SPECIAL REFERENCE TO THE SAND SOLE ( PSETTICHTHYS
MELANOSTICUS) FROM NORTHERN HECATE STRAIT, BRITISH COLUMBIA, CANADA
N1GRELLI, KETCHEN & RUGGIERI
PLATE III
FIG. 7
STUDIES ON VIRUS DISEASES OF FISHES. EPIZOOTIOLOGY OF EPITHELIAL TUMORS IN THE SKIN OF
FLATFISHES OF THE PACIFIC COAST, WITH SPECIAL REFERENCE TO THE SAND SOLE ( PSETTICHTHYS
MELANOSTICUS) FROM NORTHERN HECATE STRAIT, BRITISH COLUMBIA, CANADA
N1GRELLI, KETCHEN & RUGGIERI
PLATE IV
FIG. 8
FIG. 9
STUDIES ON VIRUS DISEASES OF FISHES. EPIZOOTIOLOGY OF EPITHELIAL TUMORS IN THE SKIN OF
FLATFISHES OF THE PACIFIC COAST, WITH SPECIAL REFERENCE TO THE SAND SOLE ( PSETTICHTHYS
MELANOSTICUS) FROM NORTHERN HECATE STRAIT. BRITISH COLUMBIA. CANADA
NIGRELLI, KETCHEN & RUGGIERI
PLATE V
FIG. 10
FIG. 11
STUDIES ON VIRUS DISEASES OF FISHES. EPIZOOTIOLOGY OF EPITHELIAL TUMORS IN THE SKIN OF
FLATFISHES OF THE PACIFIC COAST, WITH SPECIAL REFERENCE TO THE SAND SOLE ( PSETTICHTHYS
MELANOSTICUS) FROM NORTHERN HECATE STRAIT. BRITISH COLUMBIA. CANADA
NIGRELL1, KETCHEN & RUGGIERI
PLATE VI
FIG. 13
STUDIES ON VIRUS DISEASES OF FISHES. EP1ZOOTIOLOGY OF EPITHELIAL TUMORS IN THE SKIN OF
FLATFISHES OF THE PACIFIC COAST, WITH SPECIAL REFERENCE TO THE SAND SOLE ( PSETTICHTHYS
MELANOSTICUS) FROM NORTHERN HECATE STRAIT, BRITISH COLUMBIA. CANADA
N1GRELLI, KETCHEN & RUGGIERI
PLATE VII
FIG. 14
FIG. 15
STUDIES ON VIRUS DISEASES OF FISHES. EPIZOOTIOLOGY OF EPITHELIAL TUMORS IN THE SKIN OF
FLATFISHES OF THE PACIFIC COAST, WITH SPECIAL REFERENCE TO THE SAND SOLE ( PSETTICHTHYS
MELANOSTICUS) FROM NORTHERN HECATE STRAIT, BRITISH COLUMBIA, CANADA
NIGRELL1, KETCHEN 8c RUGGIERI
PLATE VIII
FIG. 16
FIG. 17
STUDIES ON VIRUS DISEASES OF FISHES. EPIZOOTIOLOGY OF EPITHELIAL TUMORS IN THE SKIN OF
FLATFISHES OF THE PACIFIC COAST, WITH SPECIAL REFERENCE TO THE SAND SOLE ( PSETTICHTH YS
MELANOSTICUS) FROM NORTHERN HECATE STRAIT, BRITISH COLUMBIA, CANADA
NIGRELLI, KETCHEN & RUGGIERI
PLATE IX
FIG. 18
FIG. 19
STUDIES ON VIRUS DISEASES OF FISHES. EP1ZOOTIOLOGY OF EPITHELIAL TUMORS IN THE SKIN OF
FLATFISHES OF THE PACIFIC COAST, WITH SPECIAL REFERENCE TO THE SAND SOLE ( PSETTICHTHYS
MELANOSTICUS) FROM NORTHERN HECATE STRAIT, BRITISH COLUMBIA, CANADA
N IGRELL! , KETCHEN & RUGGIERI
PLATE X
FIG. 20
FIG. 21
STUDIES ON VIRUS DISEASES OF FISHES. EPIZOOTIOLOGY OF EPITHELIAL TUMORS IN THE SKIN OF
FLATFISHES OF THE PACIFIC COAST. WITH SPECIAL REFERENCE TO THE SAND SOLE ( PSETTICHTHYS
MELANOSTICUS) FROM NORTHERN HECATE STRAIT, BRITISH COLUMBIA, CANADA
NIGRELLI, KETCHEN a RUGGIER!
PLATE XI
FIG. 22
FIG. 23
STUDIES ON VIRUS DISEASES OF FISHES. EPIZOOTIOLOGY OF EPITHELIAL TUMORS IN THE SKIN OF
FLATFISHES OF THE PACIFIC COAST, WITH SPECIAL REFERENCE TO THE SAND SOLE ( PSETTICHTHYS
MELANOSTICUS) FROM NORTHERN HECATE STRAIT, BRITISH COLUMBIA, CANADA
12
Waving Display and Sound Production in the Courtship Behavior of
Uca pagilator, with Comparisons to U. minax and U. pugnax1'2
Michael Salmon
Department of Zoology, University of Maryland,
College Park, Maryland
(Plates I-V; Text-figures 1-7)
I. Introduction
MALE fiddler crabs (Genus Uca ) often ex-
hibit movements of the enlarged major
cheliped called “waving” or “beckoning”
(Crane, 1957). In some species, the cheliped is
also vibrated against the substrate to produce a
series of sounds. The purpose of this study was
to determine the role of waving display and
sound production in the behavior of Uca pugi-
lator. The behavior of this sound-producing
species was compared with that of two other
local species, U. minax and U. pugnax, from
which sound production had not been reported.
The influence of temperature, tide, light, dark-
ness, sound playbacks, tactile stimuli and other
crabs on waving display and sound production
by test crabs was determined.
Comparative studies of waving in fiddler crabs
have been published by Crane (1941.1, 1943.1,
1943.2), Peters (1955) and Altevogt (1955.1).
Crane (1943.1) reported that each species had
a waving display so characteristic that it could
be used to distinguish between closely related
forms. Similarity in waving display and in cer-
tain morphological features enabled her to form-
ulate a tentative phylogeny of over thirty Pacific
American species. She proposed that evolution
within the genus involved movement from a
stable, damp habitat only briefly exposed during
low tide, to periodically dry habitats such as
sloping mud or sand flats, beaches and banks of
fresh water streams subject to seasonal drying.
1Present address: Department of Zoology, De Paul
University, Chicago.
2This work was submitted in partial fulfillment of the
requirements for the degree of Doctor of Philosophy in
the Graduate School of Arts and Sciences, University of
Maryland, College Park, Maryland.
The more specialized species showed the most
complex waving displays. After completing a
study of Indo-Pacific forms, Crane (1957) of-
fered the following explanation to account for
the evolution of waving display within the genus.
In the “narrow front” species, the males exhibited
“vertical waves” in which the major cheliped
was raised and lowered without being flexed
away from the body. In the “broad front” spe-
cies, the cheliped was flexed laterally, away from
the body, during the wave. The primitive narrow
fronts that radiated from their center of dis-
tribution in the Indo-Malay region gave rise to
the advanced broad front forms typical of Cen-
tral and South America. Species of both groups
reached their greatest complexity in waving dis-
play in relatively exposed habitats. The evolu-
tionary trend to increase the conspicuousness
of the wave of the male was expressed as follows.
The size of the male, the amount of time de-
voted to waving and the tempo of the waving
movement, particularly when a female ap-
proached, were increased. Special movements of
the body and ambulatory legs, as well as the
evolution of sound production associated with
the wave, were developed. In addition, copula-
tion, rather then taking place on the surface
of the beach or in the female’s burrow as in the
narrow fronts, took place in the male’s burrow
where the female was enticed to follow the male
by his initial waving overtures.
There has been disagreement in the literature
concerning the function of waving display.
Some authors (Muller, 1869; Darwin, 1871;
Alcock, 1892, 1902; Pearse, 1914.1, 1914.2)
believed that waving was utilized by the male
to attract the female. Verway (1930), Hediger
( 1933, 1934) and Gray ( 1942) stated that wav-
ing had no courtship function but served to
123
124
Zoologica: New York Zoological Society
[50: 12
demarcate the burrow and surrounding area as
the territory of the male. Altevogt (1955.1),
studying U. marionis and U. annulipes, assumed
that if waving demarcated a territory, the male
should stay with his burrow “. . . for longer than
just for an occasional visit or for one high tide.”
He marked males and found that between con-
secutive high tides they wandered many meters
from one burrow to another. Some of the wan-
dering males were observed to wave as they
travelled. He concluded that waving probably
was involved with courtship display and had
no territorial function. He reaffirmed this view
in other studies on the same two species and on
U. triangularis (1955.2, 1957), as well as U.
tangeri (1959). Crane (1958) also observed
waving in U. marionis even when the male
possessed no burrow and remarked that waving
by non-territorial males was typical of primitive
and semi-primitive species. Pearse (1912),
studying several species at Manila, reported that
males waved their claws frantically “ . . . but they
apparently do this to an equal extent whether
females are present or absent and without any
apparent reference to mating . . .” However, he
pointed out that his observations were not made
during the breeding season. Several authors
(Alcock, 1892; Symons, 1920; Johnson &
Snook, 1927; Beebe, 1928; Matthews, 1930;
Burkenroad, 1947; Salmon & Stout, 1962; Von
Hagen, 1961, 1962) reported that the appear-
ance of a female caused males to wave more
rapidly, implying that waving was involved in
courtship activity. Crane (1941.1) felt that “. . .
waving is certainly carried on some of the time
as a warning to other males and to delimit
territory in some (but not all) species of Uca.
On the other hand, in many, if not all species,
waving definitely plays a large part in courtship
. . .” Schdne & Schone (1963) also stated that
waving was used in courtship and in aggressive
interactions between males and based their views
on studies of U. pugilator and Goniopsis cruen-
tata in which waving also occurs.
The earliest observations on the waving dis-
play of North American forms were made by
Pearse (1914.1), Swartz & Safir (1915) and
Gray (1942), but species-specific differences in
the displays were not reported until the publi-
cation of Crane’s (1943.2) study of U. pugi-
lator, U. pugnax and U. minax. Some of her
observations on the waving display of U. pugi-
lator were confirmed by Salmon & Stout ( 1962) .
Schone & Schone (1963) briefly compared the
waving displays of U. pugilator, U. rizophorae
and U. annulipes. Tashian & Vernberg (1958)
utilized differences in waving movements, in
addition to ecological and morphological cri-
teria, to indicate the species-specificity of U.
pugnax and U. rapax (then considered subspe-
cies) where their ranges overlapped in north-
eastern Florida.
Aurivillius (1893) and Rathbun (1914) pre-
dicted on morphological grounds that stridula-
tory sounds could be produced by some species
of Uca, but none have been reported. Dem-
bowski (1925) saw male U. pugilator making
a peculiar shivering movement with the major
cheliped which resulted in sounds lasting from
1-3 seconds. The sounds produced by a crab
near the burrow entrance resulted in the ap-
pearance of another crab on the surface, which
defended its burrow. Crane (1941, 1943.1) de-
scribed sound production by rapping of the
pollex of the major cheliped against the sub-
strate during the waving displays of six tropical
American species of Uca. In most cases, the
sounds were produced by excited males just be-
fore rushing into their burrows in response to
the approach of a near-by female. A drum whirl
( “Trommelwirbel”) sound was reported in U.
tangeri by Altevogt (1959, 1962) which was
also produced by excited males, and studies by
Von Hagen (1961, 1962) revealed that the
sounds could be used in fights for possession of
a burrow, as reported by Dembowski (1925)
for U. pugilator. Two distinct types of sounds
were produced by U. tangeri, the short whirl
of 1-3 beats and the long whirl of 7-12 beats.
The short whirl occurred when the male was
temporarily obscured from the female by an
obstruction in the field or mechanically pre-
vented from waving by dense plant growth. The
time between two short whirls was found to equal
the time between two consecutive waves at the
same temperature. The long whirl was produced
by excited males just before entering their bur-
rows, in response to the approach of a female, and
by males at night in front of the burrow entrance
of conspecifics. The long whirl caused the resi-
dent in the burrow to come out. If the resident
was a female, copulation might follow. If it was
a male, aggressive encounters ensued. Females
were also able to produce the long whirl sound
and did so in aggressive encounters involving
defense of the burrow. The sounds could be
produced in at least two ways. Males with intact
major chelae produced sounds by rapping the
substrate as described for other species of Uca.
Males with small regenerating major chelae and
females produced sounds by striking the sub-
strate with alternate movements of each cheliped.
Sound production by rapidly waving males
of U. pugilator was observed by Crane ( 1943.2)
and described as a rapping movement similar
to those she observed in tropical species. Burken-
1965]
Salmon: Waving Display and Sound Production in Uca pugilator
125
Text-fig. 1. Map of the area where studies were carried out. Populations of Uca pugilator were observed
on the western beach of Pivers Island (A), on the South side of the Causeway (B) and Beaufort Basin (C).
Populations of U. pugnax were studied at more muddy areas on Pivers Island ( D) and near the North River
(not shown on map) where colonies of U. minax were also observed, about seven kilometers from
Beaufort. The Duke Marine Laboratory occupies the southern half of Pivers Island.
road ( 1947) did not believe rapping was utilized
in sound production as he could detect no dis-
turbance of the sand grains below the cheliped
of a male U . pugilator that had just produced
sounds. He reported that waving occurred during
the day and sounds were produced at night and
only during the day when excited males, inside
their burrows, had been approached by a female.
Burkenroad, and later Salmon & Stout (1962),
hypothesized that the sounds substituted for
waving when visual cues could no longer be
utilized, i.e., at night and within the confines of
the burrow.
II. Materials and Methods
All field observations and experiments were
carried out from June 15 to July 28, 1962, and
from March 21 to September 10, 1963, while
the author was at the Duke University Marine
Laboratory, Beaufort, North Carolina. In 1962,
several large colonies of U. pugilator were used
for study on the western beach of Pivers Island
(Text-fig. 1-A). These colonies were consider-
ably reduced by March, 1963. Large numbers
of U . pugilator were transferred from the south-
ern beaches of the Causeway and from the North
beach of Beaufort Basin (Text-fig. 1-B and C)
to the western beach. By mid-May a colony of
several thousand crabs had been reestablished
on Pivers Island and the behavior of the trans-
ferred crabs did not appear to deviate from res-
ident individuals in other locations. A small
colony of U. pugnax was studied in the more
muddy northwestern beaches of Pivers Island
(Text-fig. 1-D). Additional observations were
made on small and widely scattered colonies of
126
Zoologica: New York Zoological Society
[50: 12
U. pugnax and U. minax located on the western
side of the North River, seven kilometers from
Beaufort.
All three species responded to the initial pres-
ence of an observer by rushing into their bur-
rows. They usually reappeared on the surface
within a few minutes and would exhibit ap-
parently normal behavior as long as no sudden
movement was made. By remaining motionless,
it was possible to watch the crabs from dis-
tances of less than two meters. Movies of wav-
ing behavior were made with a Paillard-Bolex
16 mm. camera with 135 mm. telephoto lens
to supplement drawings and to obtain more
accurate temporal data. In some cases observa-
tions were made of male U. pugilator enclosed
in 1.6 X 1.6 meter square house window screen
pens, 20 cm. high. These crabs were observed
for five minutes at 15-30 minute intervals
throughout the day. Some observations, such
as the rate of sound production or waving by
individual males, were quantified in the field
with the aid of stop-watch and counter. Tem-
perature, tidal conditions and time of day were
also noted.
Observations at night were made with the aid
of a weak flashlight. During the breeding season,
male crabs did not react to a weak light source
for at least thirty seconds, but, as previously
reported by Burkenroad (1947), bright light
from strong flashlights induced some males of
U. pugilator to wave at night. Female crabs of
all three species appeared much more sensitive
to light and immediately went into their burrows
or moved away from the light source.
The colonies of U. pugnax and U. minax were
not located near electrical outlets, therefore an
Aiwa transistor tape recorder (Model TP-30)
and microphone were used to record sounds of
these species. The microphone was placed di-
rectly over the burrow containing the experi-
mental crab. An Ampex tape recorder (Model
301, single tract), or a Magnecorder tape re-
corder mechanism (Model PT630-A) and re-
cording and playback amplifier ( Model PT63-J )
were used to record sounds of U. pugilator on
the western beach of Pivers Island. All record-
ings were made at tape speeds of 18.75 cm.
per second (7.5 i.p.s. ) , and with the record level
adjusted so that sounds peaked at no more than
minus one on the VU meter of the tape recorder.
When the tide was below the colony, an Argonne
contact microphone (Model AR-17), enclosed
in a Saran wrap covering to prevent damage
from moisture and sand, was used to make re-
cordings. The microphone was sensitive to sub-
strate vibrations and relatively insensitive to
air-borne sounds which made possible record-
ings virtually free of background noise. A
Chesapeake Instrument Corporation hydro-
phone (Model LF-310 with N-140 internal pre-
amplifier) was used to make recordings when
the crabs were submerged at high tide. Record-
ings were made by placing the contact micro-
phone or hydrophone 2.5 cm. from the male’s
burrow entrance. A weight, usually a small shell
from the beach, was placed on top of the contact
microphone to ensure firm contact between the
microphone and the substrate. The acoustical
response of individual males was recorded in
all experiments, but in order to obtain more data
during the diel recordings, the sounds of two
males located at least two meters apart, were
recorded simultaneously. Differences in the pitch
of their rapping sounds, probably due in part to
local dissimilarities in the substrate, made it pos-
sible to distinguish between their sounds.
Sound playbacks were made by recording se-
lected portions of sounds from tapes made in
the field on a 15-second cartridge of a Mohawk
Business Machine message repeater. The portion
of the cartridge tape that stopped the playback
every 15 seconds was removed so that playbacks
were continuous. All playbacks were made
through a University submergence-proof speak-
er (Model MM-2). The speaker was placed
face down about 2.5 cm. from the crab and
equidistant between the crab and the micro-
phone. By adjusting the volume of the playback
and monitoring with a tape recorder the sound
intensity of the playback relative to the intensity
of sounds produced by the test crab could be
controlled. This procedure also enabled simul-
taneous recording of both sound playback and
acoustical response of the crab. In control tests
the speaker was placed by the crab’s burrow
but no sound was played back.
Experiments to determine if female U. pugi-
lator would orient to sounds of conspecific males
were carried out. A box 60 X 25 X 16 cm. high
was constructed of 0.6 cm. -thick plywood and
filled 7.5 cm. deep with sand. A speaker was
placed faced down at each end of the box. The
females were placed under a small cardboard
box between the two speakers. After one minute
of playback the cardboard box was lifted to
release the female. One of the two speakers was
chosen at random for the playback and each
female was used only once. One minute after the
female was released her position in the box was
noted. Tests were carried out in darkness to
eliminate possible visual cues, and at various
times of the day. The intensity of the playback
was comparable to that of males in the field.
Introduction experiments to male crabs on
the surface of the beach during the day were
made with the use of threads and probes as de-
1965]
Salmon: Waving Display and Sound Production in Uca pugilator
127
scribed previously (Salmon & Stout, 1962). The
procedure was slightly modified as follows. The
thread was marked at 2.5 cm. intervals so that
the introduced crab could be moved 15 cm. to
either side of the male’s burrow and at a speed
of about 10 cm. per second. The probes were
placed so that the introduced crab passed the
test crab at known distances from its burrow.
The test male was frightened into his burrow
when the probes and introduced crab were
placed. The experiment began one minute after
he reappeared from the burrow. The effect of
movement of a female on the behavior of a test
male was determined by forcing the female to
stand without lateral movement near the male
for one minute. She was then pulled laterally
back and forth before the male for a second
minute and finally forced to remain without
lateral movement for a third minute. The num-
ber of waves produced by the test male during
each one minute period was quantified. In
another series of tests the effect of non-moving
females on male behavior was tested. The intro-
duced female was kept hidden from the male
behind a small sand barricade and then pre-
sented, but allowed no other movement. In a
third series of tests the female was introduced
at different distances from the male’s burrow. In
these tests a microphone was placed near the
burrow so that tape recordings could be made
during the introduction. This procedure enabled
quantification of both the number of sounds
and waves made by the male during the test.
Some experiments involved the effect of
changes in light and darkness. A small desk
lamp with a 100 watt incandescent bulb was
used to test the effect of light on sound produc-
tion by male U. pugilator at night. After a con-
tact microphone was positioned the lamp was
placed about one meter from the crab so that
the light would shine directly into the burrow.
The sounds produced by the crab were recorded
for two minutes before and for two minutes
during the time when the light was turned on.
Two wooden boxes, 20 X 15 X 14 cm. high,
were constructed of 0.6 cm. -thick plywood with-
out top or bottom. The open top of one box was
covered with black plastic sheeting which made
it lightproof from below. The other box was
covered with Saran wrap. After microphones
were placed near the burrows of two males, the
boxes were placed over both the burrows and the
microphones. These boxes were used in simulta-
neous recordings of pairs of male U. pugilator
during diel experiments. Two larger boxes, 70
X 25 X 14 cm. high, covered either with black
plastic or Saran wrap, were used in sound play-
back experiments during the day. A speaker
was placed face down, 2.5 cm. from the box,
for these tests.
A single sound consisted of several (3-14)
pulses, each one of which was produced as the
cheliped of the crab was rapped against the
substrate. The sounds were usually produced in
a series with the intersound intervals much
greater than the interpulse intervals. A Kay
Electric Company Sonograph Model Recorder
(B) was used to measure the sound duration in
milliseconds, the number of pulses per sound
and the frequency spectra of the sounds. A
Briiel and Kjaer Level Recorder (Type 2305)
was used to measure intersound intervals and in
some cases the number of pulses per sound.
In order to compare the interpulse intervals
of different sounds, the following procedure was
utilized. For each sound analyzed, the sound dur-
ation in milliseconds was divided by the number
of pulses in the sound. The resulting value, re-
ferred to as the sound duration to pulse ratio, gave
a relative measure of the interpulse interval of
each sound in samples produced under different
experimental conditions or at different tempera-
tures. Means of the sound duration to pulse
ratio, number of waves, number of sounds, or
number of pulses per sound were compared
statistically with t-tests. Deviations from the
mean under different experimental conditions
were analyzed with F-tests. The .05 significance
level was chosen. The sign test was used to ana-
lyze some of the data when parametric statistics
were not applicable.
Changes in the acoustical behavior of male
crabs during introduction experiments were brief
in duration (10-20 seconds), probably because
the female crabs used in the test were not sex-
ually receptive to the males. Therefore, the
acoustical behavior of males 15 seconds immedi-
ately before and during the introduction tests
were compared. In some cases the last 5 sounds
before and the first 5 sounds during a test were
compared. These sounds were usually produced
within 15 seconds before and during the test.
III. Results
A. Seasonal Changes in Courtship Activity
During the winter, temperate zone fiddler
crabs hibernate beneath the surface (Crane,
1943.2), presumably in their burrows. In 1963,
male and female U. pugilator were first observed
on the beach at Pivers Island in early March
(Mr. Clel Bartell, personal communication).
Field observations by Mr. Bartell in early March
and by me later in the month indicated that al-
most no courtship was exhibited although many
crabs emerged from their burrows during the
day when the tide was low. Feeding, burrow
128
Zoologica: New York Zoological Society
[50: 12
repair and occasional aggressive encounters
characterized their behavior at this time. Aggres-
sive interaclions frequently took place between
neighboring resident males or between residents
and intruders and consisted of shoving and push-
ing movements with the chelae and body. In-
terlocking of the major chelae in bouts between
males, followed by twisting and pulling move-
ments, occasionally took place. One or two males
each day were observed to wave three or four
times at a near-by female but the movement was
slow and the large chela was barely elevated.
Air temperatures during many March afternoons
rose to 25 °C. and crabs often exhibited active
courtship at colder temperatures later in the
season. By early April, waving activity was
prevalent in the colonies located at Beaufort
Basin, the Causeway and Pivers Island.
During March and part of April, no nocturnal
sound production by U. pugilator was heard in
the field. When low tide occurred at night only
a few crabs opened up their burrows to the sur-
face. Air temperatures at night ranged from 10°
to I5°C. during this time. Sound production by
males was first heard the night of April 17 at
Beaufort Basin and was prevalent in all local
colonies during low tides at night by the end of
that month. Waving during the day and sound
production at night continued until late August.
By September 10, when observations ended,
sound production at night had stopped and wav-
ing was observed only on rare occasions. Tem-
peratures were still comparable to those earlier
in the season. The reduction in waving and
sound production appeared to take place within
a one-week period.
B. Results of Studies on Waving Behavior
1 . Differences in waving display between the
three species. The topography of a single wave in
U. minax, U . pugnax, and U. pugilator, all drawn
from individual frames of 16 mm. film at various
times after the wave began ( indicated below each
drawing), is shown in Text-fig. 2. The waves of
U. pugnax and U. pugilator were made by males
when no female was present. Only one male U.
minax could be filmed as he was courting a near-
by female. Under these conditions the duration
of his wave, indicated at 2.5 seconds in Text-
fig. 2, was about two to three times as fast as
those exhibited by four other males when no
female was present. The duration of waves shown
by 15 male U. pugnax ranged from 2.5 to 5.0
seconds and by 20 male U. pugilator from 1.0 to
2.0 seconds.
Other differences between the waving displays
of the three species were observed in the field.
The minor chela moved asynchronously with re-
spect to the major during waves by five male U.
minax. In three male U. pugnax the minor chela
waved twice to a single wave of the major; it
might move synchronously with the major as
shown in Text-fig. 2, or rarely it was not moved
at all. In 20 male U. pugilator the minor chela
moved synchronously with the major, or rarely
was not moved at all. The major chela was raised
and lowered once in a series of four to seven
jerks in U. minax and without any associated
lifting movements of the ambulatories. In U.
pugnax the major chela was raised, extended
laterally and returned immediately to the front of
the body in a smooth continuous movement. The
second, third, or both pairs of ambulatories on
both sides of the body were raised and lowered
just before and after the major chela reached its
maximum lateral extension. In U. pugilator the
major chela was raised vertically, held at a max-
imum elevation for a fraction of a second, then
extended laterally and returned to the front of
the body. The ambulatories on the side opposite
the major chela were rasied once as the chela was
extended laterally from its maximum elevation.
In all three species the approach of a female
caused an increase in the rate of waving by male
crabs. When the female approached to within
4-6 cm. of the male’s burrow the form of the
wave changed as follows. The lateral extension
of the male’s claw during each wave no longer
occurred. Rather, the claw was vertically lifted,
and then lowered before the body as in the nar-
row front species. During this stage of courtship
male U. pugilator usually vibrated the claw
against the substrate to produce a series of
sounds. The vibration movements occurred be-
tween two consecutive waves, when the claw
was lowered from its maximum vertical eleva-
tion, and just before it was raised again. No
sound production was observed in U. minax or
U. pugnax during this stage of courtship.
The three species showed differences in male
group display behavior. Waving by U. pugnax
and U. minax was infrequent and of short dura-
tion when no female was present. In contrast,
groups of male U. pugilator waved almost con-
tinuously in the absence of females except for
brief periods of feeding, fighting and burrow
repair. Further, males in any one area of the
colony often began to wave rapidly in groups,
when no female was present. On other occa-
sions similar group waving by males started
when one male, in response to an approaching
female, began to produce sounds. Other males
within a one meter distance would then increase
their rate of waving even after the female had
moved away or had entered the sound-produc-
ing male’s burrow. The sounds were also cor-
1965]
Salmon: Waving Display and Sound Production in Uca pugilator
129
Text-fig. 2. Single waves of Uca minax (top two lines), U. pugnax (middle two lines) and U. pugilator
(bottom line ) . Sequences start at left and continue to the right through consecutive movements. The time ( in
seconds) below each sequence is the time from the beginning of the wave. For further explanation, see
text.
related with the sudden appearance of nearby
males, previously in their burrows, on the sur-
face of the beach. These newly emerged males
immediately joined other males in group waving
activity.
2. Results of introduction experiments. The
average number of waves by 30 male U. pugi-
lator 5 seconds before and 5 seconds during in-
troduction of conspecific females from behind
sand barricades is shown in Table 1 . The average
rate of waving nearly doubled during the 5-sec-
ond period of the introduction. The increase was
statistically significant at the .01 level. The effect
of movement by females on the waving by males
is shown in Table 2. The mean rate of waving
more than doubled when the female was moved
after she had previously been held without lateral
movement before the male. The rate was greatly
reduced after lateral movement. When com-
pared with t-tests, the mean number of waves
during all three periods was found to differ sig-
nificantly from one another. During periods
when the females were held motionless they were
attacked by 13 of the 30 test males. As soon as
the female was moved the attacking males im-
mediately began to wave at a high rate.
Table 1 . The Mean Number and Standard Devia-
tion of Waves by 30 Male Uca pugilator 5 Sec-
onds Before and During Introductions in Front
of Their Burrows of Conspecific Females from
Behind Sand Barricades
Before
During
Introduction
Introduction
t-Value
Mean
2.7
5.9
45.07*
S D
0.8
1.0
*Means differ significantly at the .01 level.
130
Zoologica: New York Zoological Society
[50: 12
Table 2. The Mean Number and Standard Deviation of Waves by 30 Male Uca pugilator One
Minute Before, During and After Continuous Movement of a Conspecific
Female Before Their Burrows
Before
Movement
(A)
During
Movement
(B)
After
Movement
(C)
t-Value
Mean
12.8
28.2
3.9
t(AxB) — 5.19*
t(AxC) = 3.72*
S D
11.2
11.8
7.0
t(BxC) = 10.13*
*Means differ significantly at the .01 level.
The effect of movement of other female Uca
was also determined and the results are shown
in Table 3. In all cases, there was a significant
increase in the mean rate of waving during the
period when the female was moved. The two
female U. rapax used in these tests (obtained
from Florida), elicited more waves from males
than did females of local species.
More than twenty male U. pugilator were re-
leased singly into areas of the colony containing
conspecific resident males. The released males
wandered through the colony, approached resi-
dent males and females, and tried to enter their
burrows. In all approaches by released intruding
males, resident males stopped waving and as-
sumed typical aggressive postures with the major
chela oriented toward the intruding males. When
the intruders moved away the residents started
waving again. In other cases ritualized fighting,
consisting of pushing and twisting movements
of the interlocked major chelae, would take
place. In over 80 per cent of these aggressive
encounters the resident males retained their bur-
rows. Resident males were never observed to in-
crease their waving rates when approached by
other males unless the intruding males were very
small, possessed a small major chela (typical of
males regenerating a new claw) or approached
with their bodies between their major chela and
the residents.
3. Results of sound playback experiments. The
results of sound playback of 56 sounds per min-
ute to 30 male U. pugilator are shown in Table 4.
The mean rate of waving by males before the
playback was low, probably because of the pres-
ence of the speaker near their burrows. During
the one minute playback the mean rate of wav-
ing increased almost four times. The mean rate
after the playback was reduced but still signifi-
cantly greater than the rate before the playback.
The sound playback of 56 sounds per minute
contained the greatest number of sounds ever
recorded from a male during a 15-second period
(14 sounds per 15 seconds) and probably was
Table 3. The Mean Number and Standard Deviation of Waves by 10 Different Male
Uca pugilator During One Minute Periods Before, During and After Continuous
Movement of Single Female Uca spp. Before Their Burrows
Species
Female
Before
During
After
of
Carapace
Movement
Movement
Movement
t-Value
Female
Width (cm.)
(A)
(B)
(C)
Mean:
6.5
20.5
5.2
t(AxB) = 2.64*
U . minax
1.7
SD:
5.9
15.7
16.5
t(AxC) = 0.26
t(BxC) = 2.70*
Mean:
9.5
19.6
6.9
t(AxB) = 2.30*
U . minax
1.8
S D:
12.9
8.6
7.5
t(AxC) = 0.62
t(BxC) = 3.53t
Mean :
11.8
30.5
10.6
t(AxB) = 3.56t
U. rapax
2.0
SD:
9.2
13.9
12.9
t(AxC) = 0.00
t(BxC) = 3.32t
Mean :
10.4
40.7
10.6
t(AxB) = 5.88t
U. rapax
1.7
SD:
9.0
13.9
9.6
t(AxC) = 0.02
t(BxC) = 5.84t
Mean:
8.2
22.4
11.0
t(AxB) = 2.69t
U. pugnax
1.3
t(AxC) = 0.63
SD:
12.2
11.4
7.8
t(BxC) = 2.61*
*Mean during movement of female (B) differs significantly from other means (A or C) at the .05 level.
tMean during movement of female (B) differs significantly from other means (A or C) at the .01 level.
1965]
Salmon: Waving Display and Sound Production in Uca pugilator
131
Table 4. The Mean Number and Standard Deviation of Waves by 30 Male Uca pugilator
Before, During and After Sound Playback of 56 Sounds per Minute
Before
Playback
(A)
During
Playback
(B)
After
Playback
(C)
t-Value
Mean
4.4
17.2
8.0
t(AxB) = 8.76*
t(AxC) = 2.58*
SD
4.1
6.8
6.6
t(BxC) = 5.29*
♦Means differ significantly at the .01 level.
near to the maximum rate of sound production
for the species.
Males frightened into their burrows were
tested for emergence time with and without
sound playback and the results are shown in
Table 5. With no sound playback, six males took
a minute or more to emerge and seven did not
emerge within the two-minute test period. When
sounds were played back to another 20 males,
16 emerged within one minute after the play-
backs began and only one male remained in his
burrow during the entire test period.
C. Results of Studies on Sound Production
1 . Results of field observations. The behavior
of 25 male U. pugilator as they were approached
by females is shown in Table 6-A. In all obser-
vations, approach by the female resulted in
sound production by the male. If the female ap-
proached slowly, sound production by males was
preceded by many (15-25) waves delivered at
a high rate. This type of approach by females
was most often observed. When females ap-
proached quickly or in several short spurts, verv
few waves were exhibited by the males. The be-
havior of females once at the male’s burrow is
shown in Table 6-B. In most cases the females
entered the burrow but left immediately. In a
few observations they completely by-passed the
burrow or entered and remained with the male
for over two minutes.
At night, males in the upper third of the beach
at Pivers Island produced sounds almost con-
tinuously when the tide was low. There appeared
to be no monthly changes in this behavior, as
recordings of many males in the same areas of
the beach were obtained on consecutive nights
when the tide was low. However, no observa-
tions on the acoustical behavior of individual
males throughout the summer were made. Sound
production at night was inhibited when there
were strong winds and rain. The number of
sound-producing crabs increased while the tide
was receding and reached a maximum on the
incoming tide. The transition from waving to
sound production was observed when low tides
coincided with sunset. Within 30 minutes after
sunset, waving stopped. Almost all male crabs
would enter their burrows and remain there for
about one hour. At first, only a few males would
produce a brief series of sounds. But within one
hour after sunset most of the males were pro-
ducing sounds from inside their burrows. During
the second hour after sunset the males would
move up to the entrances of their burrows where
they continued to produce sounds until the in-
coming tide and/or sunrise resulted in cessation
of this behavior. One sound-producing male in
position and the impression made by the rapping
major chela in the sand is shown Plate I. The
Table 5. The Time of Emergence in Seconds
from Their Burrows of 20 Male Uca pugilator
With and Without Sound Playback of 56 Sounds
Per Minute for Two Minutes1. 2
Male
Number
Without
Sound
Playback
(Controls)
With
Sound
Playback
( Experimentals)
1
DNE*
50
2
15
65
3
35
20
4
70
35
5
105
90
6
DNE
15
7
100
21
8
120
35
9
35
30
10
DNE
45
1 1
15
45
12
20
DNE*
13
50
14
14
60
25
15
118
90
16
50
20
17
DNE
25
18
DNE
30
19
DNE
7
20
DNE
15
*DNE: Did not emerge from
their burrows within
the two-minute test period.
tTwenty different males, tested alternately, were
used for each series.
2The number of control crabs that DNE is signifi-
cantly greater than the number of experimentals at the
.01 level (Chi-square = 5.62). The number of experi-
mental crabs emerging sooner than control crabs is
significantly greater at the .01 level (Sign test value
= 3).
132
Zoologica: New York Zoological Society
[50: 12
Table 6. A Summary of the Courtship Behavior of Male and Female Uca pugilator During the Day
A. The Approach of the Female to the Male
Behavior of
Female
Response of
Male
Number of
Observations
Slowly approaches the male
Many waves, followed by sound
production at the burrow entrance
18
Approaches the male quickly
Few waves, followed by sound
production inside the burrow
3
Female approaches the male
in 4-5 short spurts
Few waves, followed by sound
production outside or inside the burrow
4
B. The Behavior of Females at the Male’s Burrow
By-Passes Enters Burrow, Then
Burrow Leaves Immediately
Remains in Burrow
Over 2 Minutes
Number of Observations
9
21
4
male’s body was either slightly elevated or the
ventral surface sometimes touched the ground.
The ambulatories on the major side were ex-
tended and spread. The movement of the chela
before, during and after one rap against the
substrate is shown in Text-fig. 3 A-C. A single
sound as defined here was composed of several
(3-14) pulses, each one of which was produced
as the chela struck the substrate.
The results of per minute tallies of sounds for
15 minutes by eight males at night are shown
in Table 7. All but two males produced sounds
within each minute during the entire 15-minute
period. The range in per minute production by
each crab varied from 6 to 22 sounds during
these observations.
The mean, first standard deviation, and range
of per minute sound production by samples of
males at different air temperatures is shown in
Text-fig. 4. The mean number of sounds pro-
duced per minute increased with higher temper-
atures although there was considerable variation
in the number of sounds produced by any one
crab within each sample. Five sounds from re-
cordings of ten different males at 14°, 18.5° and
24° C. were selected at random and analyzed
sonographically. The sound duration, number of
pulses per sound and sound duration to pulse
ratio were calculated for each sound. The results
are shown in Text-fig. 5 A-C. Sounds produced
at higher temperatures were of shorter duration
and had smaller sound duration to pulse ratios.
There was no significant difference between the
mean number of pulses per sound at the three
temperatures. Sonograms of one sound produced
at each temperature are shown in Plate II. The
mean time interval between sounds of 20 male
U. pugilator at 24° C. was found to be 2.9 s.ec-
Table 7. The Number of Sounds per Minute Produced by Each of 8 Male Uca pugilator
at Night During a 15-minute Period
Time (in
Minutes)
1
2
3
Male Number
4 5
6
7
8
1
26
13
18
19
32
26
24
25
2
25
21
21
22
35
22
20
22
3
25
18
22
20
31
22
18
19
4
23
9
15
20
28
23
20
24
5
29
0
21
10
28
21
20
25
6
26
8
18
14
27
28
19
25
7
29
14
16
23
26
9
5
16
8
29
11
2
3
26
22
17
19
9
24
15
2
6
25
16
23
21
10
25
11
0
14
23
22
17
22
11
29
14
0
17
20
20
20
25
12
27
22
0
19
27
20
19
21
13
23
19
0
16
25
21
18
18
14
25
19
0
16
26
22
19
18
15
23
16
11
17
28
14
20
26
Range:
23-29
0-22
0-22
3-23
20-35
9-28
5-24
16-26
1965]
Salmon: Waving Display and Sound Production in Uca pugilator
133
onds with a range of 1.8 to 5.2 seconds. The
average standard deviation was 1 .65 with a range
from 0.5 to 4.1.
Resident male U. pugilator at night, when
touched by another crab, increased their rate of
sound production while simultaneously moving
6-20 mm. into their burrows. This behavior was
accompanied by rapid and repeated extension
and retraction movements of the ambulatories
on the side of the crab toward the burrow en-
trance. If the intruding crab followed the resi-
dent into the burrow, the resident’s ambulatories
would touch him when they were extended. The
resident responded to this contact by moving still
farther into his burrow and producing a rapid
series of five to ten sounds. If the ambulatories
did not touch the intruding crab, the resident
stopped producing sounds and moved toward
the burrow entrance. Both males and females
were observed to release this behavior in resident
males but only females, four in total, were ever
observed to move into the burrow of a sound-
producing male. An intruding male either moved
away from the resident’s burrow or struck the
resident sharply with the major chela, which
caused the resident to stop sound production and
adopt defensive postures. Aggressive behavior in
resident males at night could be elicited in a few
instances by striking the male sharply with the
flat surface of an autotomized chela from an-
other male. Sound production at a high rate and
associated ambulatory movements could be elic-
ited by gently touching the resident male with
an autotomized leg of another crab, a pencil
point, a blunt wooden stick or a leaf tip. The
results of tactile stimulation of male U. pugilator
with a leaf of Spartina are shown in Table 8.
Contact between the leaf and the crab’s leg, dor-
sal or posterior parts of the carapace, or major
chela usually resulted in sound production at a
high rate. There was a slight tendency for males
to respond aggressively to gentle tactile stimula-
tion of the major chela.
The rate of sound production by groups of
males was also observed to increase when a near-
by male, probably due to tactile stimulation by
another crab, increased his rate of sound pro-
duction. In addition, previously silent males in
the vicinity would begin to produce sounds.
2. Results of introduction experiments. Fe-
male U. pugilator were introduced during the
day at 2.5, 5.0, 7.5 and 10.0 cm. distances from
the burrows of groups of ten conspecific males.
The results are shown in Text-fig. 6. The males
produced many sounds at the burrow entrance
and few waves when the females were intro-
duced at 2.5 cm. from the burrow. As the fe-
males were introduced farther from the burrow.
,2.5 CM f
Text-fig. 3. Drawings of a male Uca pugilator pro-
ducing sounds just outside the entrance of his bur-
row. A-C: Movements of the major chela before
(A), during (B) and after (C) one rapping move-
ment of the chela against the sand.
the males produced many waves but progres-
sively fewer sounds.
The number of sounds produced by 30 male
U. pugilator 15 seconds before and during intro-
duction of conspecific males and females into
their burrows is shown in Table 9. During the
day none of the males produced any sounds be-
fore the introduction but at night all males were
rapping continuously before the test. The test
males produced about the same number of
sounds regardless of the sex of the introduced
134
Zoologica: New York Zoological Society
[50: 12
AIR TEMPERATURE IN DEGREES CENTIGRADE
Text-fig. 4. The correlation between temperature and the rate of sound production by male Uca pugilator
during 1963. In each sample, the vertical line indicates the sample range: the number below, the sample
size in numbers of animals; the horizontal line, the mean; and the broad portion of the line, the first stand-
ard deviation on each side of the mean. The samples were obtained from one-minute tape recordings or
direct observation in the field. The month/date when the data was recorded is shown above each sample.
crab. The average rate of sound production dur-
ing nocturnal introductions was significantly
greater than the average rate before introduc-
tions and was similar to the rate during day-time
introductions. The last 5 sounds produced by 30
male U. pugilator before, and the first 5 sounds
during, nocturnal introductions of conspecific
females were chosen for analysis. The mean num-
ber of pulses and variance in pulse number be-
fore and during the introduction are shown in
Table 10. There was no significant difference
between the mean number of pulses but the vari-
ance in pulse number per sound was greater dur-
ing the introduction. One of the last 5 sounds
before and one of the first 5 sounds during in-
troductions of females to 15 male U. pugilator
were selected at random and the sound duration
to pulse number ratio was compared. The results
are shown in Table 11. The mean ratio after the
introduction was significantly less than the ratio
before introduction, reflecting the decrease in
interpulse intervals after the introduction. A
sonogram of two sounds produced by the same
male before and after the introduction of a fe-
male is shown in Plate III and illustrates the
Table 8. The Response at Night by Male Uca pugilator to Tactile Stimuli with a Leaf
of Spartina on Various Parts of the Body1
Place of
Stimulation
Number of Responses Observed
High Rate Sound
Production
Aggressive Response
Goes Into Burrow
Ambulatories
18
2
0
Face of Chela
14
5
1
Dorsal Carapace
17
0
3
Posterior Carapace
16
1
3
1Twenty different males were used in each test.
1965] Salmon: Waving Display and Sound Production in Uca pugilator 135
Table 9. The Mean Number and Standard Deviation
of Sounds Produced by
30 Male Uca
pugilator
15 Seconds
Before and During
Introduction of Conspecific
Males
and Females into
Their
Burrows
Sex of
Time of
Before
After
Introduced
Introduction
Introduction
Introduction
t-Value
Crab
Mean:
0.0
10.7
Female
Day
S D:
5.5
Mean:
0.0
10.6
Male
Day
SD:
6.9
Mean:
5.9
10.2
Female
Night
S D:
2.4
3.4
5.51*
Mean:
5.0
8.8
Male
Night
SD:
2.1
4.3
4.28*
*Mean number of sounds during introduction is significantly greater than mean before introduction at the .01
level.
reduction in interpulse intervals of sounds pro-
duced during the introduction.
Male U. pugnax produced sounds when a total
of 1 8 females (14 U. pugnax and 4 U. pugilator)
and 7 conspecific males were introduced into
their burrows during the day. From 3 to 16
sounds were produced one minute after the
introduction. The sound duration, pulse number
per sound and interpulse intervals of the sounds
were highly variable. Some sounds consisted of
only one or two pulses and lasted less than a sec-
ond while others consisted of up to 30 pulses
and lasted over 5 seconds. The same crab pro-
duced sounds of long and short duration during
a single recording. The movements involved in
sound production were never observed, as the
test male was always deep in his burrow and hid-
den by the introduced crab. No sounds were
made by the test males until the introduction of
another crab. A sonogram of these sounds,
which seemed similar to stridulation sounds, is
shown in Plate IV.
Table 10. The Mean Number and Variance of
Pulses per Second Produced by 30 Male Uca
pugilator Before and During Introduction of
Conspecific Females1
Before
During
Introduction
Introduction
Mean
6.7
7.1*
Variance
9.37
24.63t
!The last five sounds before and the first five sounds
during the introduction of the female were chosen for
analysis.
*No significant difference between means (t = 0.08).
tVariances differ significantly at the 0.1 level (F
- 2.63).
On two occasions male U . pugnax produced
rapping sounds much like those of U. pugilator
but at a much slower rate (3-5 pulses per 5 sec-
onds) . Unfortunately no tape recordings of these
sounds were obtained.
Introduction of female U. pugilator into the
burrows of 30 conspecific females resulted in the
production of two sounds by one female. One of
the sounds consisted of 40 pulses and lasted 12
seconds; the other, of 73 pulses and lasted 29
seconds. A sonogram of a portion of one of the
sounds is shown in Plate IV. Another female,
nudged roughly with a stick at night, assumed
a defensive posture and hit the substrate with
alternate movements of her two minor chelae
for a few seconds before rushing into her bur-
row. The sounds from this female were similar
to those recorded during the day.
No sounds were produced by male U. minax
in response to introductions of other crabs.
3. Results of sound playback experiments. The
acoustical response of 20 male U. pugilator at
Table 1 1 . The Mean and Standard Deviation of
the Sound Duration to Pulse Ratio of One
Sound Produced by 15 Male Uca pugilator at
Night Before and During Introduction into
Their
Burrows of a
Conspecific Female1
Before
Introduction
During
Introduction
t-Value
Mean:
72.01
65.31
SD:
7.6
9.8
3.200*
!One of the last five sounds before and one of the
first five sounds during the introduction of a female to a
male were selected at random for analysis.
*Means differ significantly at the .01 level.
136
Zoologica: New York Zoological Society
[50: 12
I 4° C —
1 8.5° C
2 4° C —
SOUND DURATION IN MILLISECONDS
LlJ
o
UJ
3
o
ratio: sound duration/number of pulses
Text-fig. 5. The sound duration in milliseconds
(A), number of pulses per sound (B) and the ratio
of the sound duration to the-number of pulses (C)
of five seconds selected at random from those pro-
duced by each of ten males at 14°, 18.5° and 24° C.
All are plotted against frequency of occurrence.
The procedures utilized to make this analysis are
described under Materials and Methods.
night before, during and after one minute of
sound playback at different rates is shown in
Table 12. The average rate of sound production
by males during the playback of 24 and 56
sounds per minute was significantly greater than
the rate before and after the playback. With
playbacks of 48 sounds per minute, the average
rate after the playback differed significantly
from the average rate before the playback. When
the tape of 56 sounds per minute was reversed
before playback, the males produced a signifi-
cantly greater number of sounds during the play-
back than they did before the playback. The
other mean rates of sound production during
experiments did not differ significantly.
The effect of sound playback at night on silent
males previously frightened into their burrows is
shown in Table 13. Nine of 15 males not re-
ceiving sound playbacks during the four-minute
test period remained silent and all but two pro-
duced no sounds for one minute. One of 15
males receiving sound playbacks remained silent
and all but two males produced sounds within
one minute after the playback began. The in-
crease in mean number of sounds produced by
males receiving the playback was significant at
the .01 level.
Playbacks of 16 and 24 sounds per minute
were made at night to male U. pugilator for a
three-minute period to determine if the males
would synchronize their sounds with those of
the playback. The results are shown in Table 14.
There was no significant difference in the mean
rate or between variances of the sounds pro-
duced during and after the playback.
The results of sound playbacks to single males
under light-proof and clear-topped boxes during
the day are shown in Table 15. No males pro-
duced sounds under either box one minute be-
fore the playback, probably because the experi-
ment began within a few seconds after the box
had been placed over the crabs’ burrows. During
the playback there was a significant increase in
the mean number of sounds produced by males
under the light-proof box. During the one min-
ute period after the playback the males under
the light-proof box continued to produce a
greater number of sounds than those under the
clear-topped box. When the light-proof box was
placed over the burrows of 1 1 other males, but
without sound playback, the males produced no
sounds for at least three minutes.
A total of 54 female U. pugilator was tested
in the laboratory with playbacks of sounds from
conspecific males to determine if they would be
attracted to the sound source (See Materials
and Methods for procedure). Of these, 15 did
not move from the center of the box during the
playback. All the other females moved to and
remained against the right or left side of the box,
behind one of the two speakers. A total of 25
females moved to the experimental speaker
through which sounds were emitted while 14
moved to the silent control speaker. The prefer-
ence for the experimental speaker was not sig-
nificant at the 0.5 level (Chi-square=3.10).
D. Effect of Light and Darkness on Sound
Production and Waving Behavior
The results of three days of observations on
the behavior of male U. pugilator surrounded by
screen pens are shown in Table 16. Aggressive
interactions between males, feeding behavior
and burrow repair were consistent patterns of
behavior occurring frequently during the day
1965]
Salmon: Waving Display and Sound Production in Uca pugilator
137
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Text-fig. 6. The number of waves (upper graph) and the number of sounds (lower graph) produced
by ten different male Uca pugilator during one-minute introductions of conspecific females is shown. The
females were introduced during the day and at 2.5, 5.0, 7.5 and 10.0 cm. from the males’ burrows.
and at night. Waving behavior was observed only
during the day. The behavior of males in the
field deviated from those in the pens only in that
unconfined males occasionally produced sounds
during the day when females came near to their
burrows. Females were unable to scale the screen
walls of the pens surrounding the males utilized
for observations. The data show that on June 22,
waving behavior was exhibited by confined males
until 1945 hours, but not afterward, and sound
production started at this time and continued
until 2130 hours, or just before the high water
mark came near and the crabs went into their
burrows. On June 26 and 28, waving again was
exhibited only during the day and, in nightly
observations for two-hour periods, sounds were
heard.
The results of tape recordings near the bur-
rows of pairs of male U. pugilator during low
tides for a 24-hour period are shown in Text-
fig. 7 A-D. Continual sound production during
low tides occurred only at night. A few sounds
produced during the day were made by males
when a female approached their burrows. On
May 6 and June 4-5, sound production ended
shortly before sunrise and when the tide had ap-
proached near to the burrows of the males. On
July 21-22 and August 19-20, sound production
138
Zoologica: New York Zoological Society
[50: 12
Table 12. The Mean Number and Standard Deviation of Sounds Produced by 20 Male
Uca pugilator at Night Before, During and After One Minute of Sound Playback at
Different Rates and at an Intensity
of One-half that of the Male’s Sounds
Number of Sounds
Before
During
After
Per Minute in
Playback
Playback
Playback
t-Value
Playback
(A)
(B)
(C)
Control
Mean:
21.0
17.9
18.9
t(AxB)
= 1.24
(No Playback)
t(AxC)
= 0.71
SD:
7.6
8.2
10.8
t(BxC)
= 0.33
Mean:
15.5
18.3
16.3
t(AxB)
= 1.85
16
t(AxC)
= 0.68
SD:
3.9
5.5
3.6
t(BxC)
= 1.37
Mean:
20.8
25.5
21.6
t(AxB)
= 2.83*
24
t(AxC)
= 0.34
SD:
6.9
8.4
7.8
t(BxC)
= 2.12*
Mean:
20.7
20.6
19.4
t(AxB)
= 0.02
32
t(AxC)
= 0.52
SD:
5.6
7.1
8.7
t(BxC)
= 0.47
Mean:
20.5
19.6
20.7
tCAxB)
= 0.35
40
t(AxC)
= 0.08
SD:
6.3
9.5
8.5
t(BxC)
= 0.39
Mean:
24.4
25.2
28.9
t(AxB)
= 1.35
48
t(AxC)
- 3.42t
S D:
5.9
7.7
6.1
t(BxC)
= 1.78
Mean:
16.9
29.6
17.9
t(AxB)
= 6.6 It
56
t(AxC)
= 0.56
SD:
6.1
6.0
5.0
t(BxC)
= 6.69t
Mean:
18.6
25.3
21.5
t(AxB)
= 3.14*
56
t(AxC)
= 1.12
(Reverse)
SD:
6.7
11.9
8.2
t(BxC)
= 1.11
*Means differ significantly at the .05 level.
tMeans differ significantly at the .01 level.
Table 13. Number of Sounds and Time of First Sound Produced by Male Uca pugilator at
Night During Four Minutes With or Without Sound Playback of 56 Sounds per Minute1
With Sound Playback
Without Sound Playback
Male
Time of First
Number of
Male
Time of First
Number of
Number
Sound (In Seconds)
Sounds
Number
Sound (In Seconds)
Sounds
1
6
84
1
None Heard
0
2
51
25
2
226
1
3
7
1
3
None Heard
0
4
80
28
4
None Heard
0
5
5
120
5
None Heard
0
6
None Heard
0
6
18
19
7
80
2
7
None Heard
0
8
6
81
8
104
16
9
20
7
9
None Heard
0
10
11
51
10
23
106
11
2
106
11
None Heard
0
12
11
85
12
None Heard
0
13
164
5
13
114
12
14
11
121
14
79
17
15
9
128
15
None Heard
0
Mean:
56.3*
Mean:
11.4
SD:
49.3
SD:
27.2
1Fifteen different males, tested alternately, were used with and without sound playback.
*Means differ significantly at the .01 level (t = 3.0965).
NUMBER OF SOUNDS PER HOUR
1965]
Salmon: Waving Display and Sound Production in Uca pugilator
139
/ TIME OF DAY
Text-fig. 7. The number of sounds per hour produced by pairs of male Uca pugilator recorded simul-
taneously during low tides for a twenty-four hour period. A-D: number of sounds produced by males
under normal day-night cycles; E-F: number of sounds produced by a male under a light-proof box
(dashed lines) and a box covered with clear Saran wrap (solid lines). In the time scale, 0 and 24 cor-
respond to midnight and 12 to noon. The time of high tide, low tide, sunrise (SR) and sunset (SS) are
also indicated.
140
Zoologica: New York Zoological Society
[50: 12
Table 14. The Mean Number per Minute and
Standard Deviation of Sounds Produced by 10
Male Uca pugilator at Night During and After
Three Minutes of Sound Playback at an Inten-
sity One-half that of the Male1
Number of
Sounds Per
Minute in
Playback
During
Playback
After
Playback
t-Value
Mean
: 16.9
16.0
16
S D:
4.5
2.9
0.69*
Mean
: 16.7
17.9
24
SD:
8.3
4.7
0.92*
!Two different groups of ten males were used with
each different playback.
*No significant difference between means during and
after the playback.
ended shortly before sunrise but when the tide
was still quite low. The results of simultaneous
recordings of pairs of males, one under a light-
proof and the other under a clear-topped box,
are shown in Text-fig. 7-E. On July 24-25 the
male under the dark box (dashed lines) pro-
duced sounds during the day as well as at night
from 1300 to 2200 hours while the male under
the clear-topped box produced no sounds until
after sunset. Both crabs stopped producing
sounds when the tide approached their burrows
(2200 hours) and started again when the tide
retreated (0100 hour). The male under the
clear-topped box stopped producing sounds
again just before sunrise, while the male under
the dark box continued to produce 'sounds,
though at a low rate. The experiment was re-
peated for a six-hour period in September with
another pair of males (Text-fig. 7-F). The male
under the light-proof box continued to produce
sounds during the day but at a lower rate, pos-
sibly reflecting the decline in reproductive ac-
tivity in the colony during this time. No sounds
were produced by the control crab.
No sounds were detected in recordings with
a hydrophone during high tide periods during
the day or at night. However, it is quite possible
that the hydrophone might not have detected
sounds produced in the burrows after the burrow
entrances were sealed closed with sand plugs by
the crabs.
The effect of light on sound-producing males
at night is shown in Table 17. The 10 experi-
mental and 10 control crabs produced sounds at
comparable rates two minutes before exposure
to light. After the light was turned on the ex-
perimental crabs produced many fewer sounds
than they did the previous two minutes but the
control crabs continued to produce sounds at the
normal rate. Light also caused many males to
start waving, especially if the light source was
brighter than the 100 watt bulb used in experi-
ments. One such waving male is shown in Plate
V. The photograph was taken less than ten sec-
onds after he was exposed to a 150 watt light
source.
No sound production was observed at night in
colonies of U. pugnax and U. minax. Usually,
U. minax remained inside their burrows at night
but some V . pugnax were always feeding just
outside their burrows. Both species exhibited
waving behavior during the day, as did U. pugi-
lator.
IV. Discussion
A. Seasonal Changes in Courtship Behavior
Field observations in early March, 1963, sug-
gested that male U. pugilator did not exhibit any
courtship behavior for at least a month after
hibernation ended. Since air temperatures in
March afternoons were often higher than during
days when courtship was observed in the sum-
mer, presumably some physiological state of the
crabs rather than air temperature was responsi-
ble for this lack of reproductive activity. Tem-
perature was almost certainly not a factor in the
sudden decline of waving activity and sound
production that took place in September but,
rather, the cessation of courtship activity prob-
ably reflected endocrine changes.
Changes in the courtship of other Uca species
also appear to be independent of temperature.
Von Hagen (1962) reported that in U. tangeri
nocturnal wandering and copulation were ob-
served during June and July, 1960, and predom-
inantly on nights of the new moon. Also, females
exhibited a monthly cycle of egg development
during these periods. Crane (1958) found that
Table 15. Mean Number and Standard Deviation
of Sounds Produced by 30 Male Uca pugilator
Under Light-proof and Clear-topped Boxes One
Minute Before, During and After Sound Play-
back During the Day1
Box Type2
Before During After
Playback Playback Playback
Mean: 0.0
6.5
7.8
Light-proof
SD:
8.2
7.8
Mean: 0.0
0.1
0.1
Clear-topped
SD:
iThe sound playback consisted of 56 sounds per min-
ute.
^Thirty different males, tested alternately, were used
under each box type.
1965] Salmon: Waving Display and Sound Production in Uca pugilator 141
Table 16. The Number of Male Uca pugilator in a Screen Pen Exhibiting Waving Behavior
or Sound Production at the Burrow Entrance During Various Times of the Day
I. June 22, 1962:
8 Males
Time:
1615
1630
1700
1810
1840
1910
1945
2015
2100
2130
2200
Waving
1
1
1
6
2
4
1
0
0
0
*
Sound Production
0
0
0
0
0
0
2
5
3
2
*
II. June 26, 1962:
9 Males
Time:
0800
0830
0900
0930
1000
1030
1100
1130
1200
1230
2100
2130
Waving
5
6
7
5
4
3
5
3
2
*
0
0
Sound Production
0
0
0
0
0
0
0
0
0
*
1
3
III. June 28, 1962
: 9 Males
Time :
0900
0930
1000
1030
1100
1130
1200
1230
1300
1350
2330
00-15
Waving
4
7
4
2
8
5
5
5
4
*
0
0
Sound Production
0
0
0
0
0
0
0
0
0
*
4
5
*High water mark near to or over crabs which have gone into their burrows.
male U. maracoani showed five to six general
changes in their behavior patterns over a period
of days or weeks during the breeding season.
The males went through periods when they re-
mained in their burrows during low tide, then
underwent wandering-nonagressive, wandering-
aggressive, territorial and, finally, a display
phase when they waved and were behaviorally
dominant to males in all other phases. Prelimi-
nary dissections indicated that these changes
were not correlated with changes in gonadal state
and Crane therefore attributed control of the
phases to some other endocrine gland.
B. Comparisons Between Waving Display in
the Three Species
The descriptions of waving display in the three
species agreed in general with those of Crane
(1943.2) but there were some differences. The
single jerk or several jerks she reported in U.
pugnax as the major cheliped was returned to the
front of the body were not observed. Rather,
both the lateral extension and return of the chela
to the front of the body appeared to be a smooth
continuous gesture. I did not see the elevation
of the ambulatories she reported during the wave
of U. tninax but this may have been due to the
sharply sloping mud bank where field observa-
tions were carried out, which could have inhib-
ited ambulatory movements during the wave.
Our data on wave durations in the three species
are comparable. However no precise quantita-
tive studies have been published in which varia-
tion within waves of individuals or within a spe-
cies have been quantified. Crane ( 1943.2) stated
that in the study of North American species of
fiddlers, the geographic locality was of no impor-
tance. It is possible that crabs at extremes of their
geographic ranges might show differences in dis-
play.
Differences in group waving display in the
three species can be correlated with their evolu-
tion within the genus. Crane (1943.2), on the
basis of anatomical and behavioral evidence,
placed U. pugnax and U. minax in her “group 2”
species which she characterized as relatively
primitive, mud-dwelling forms exhibiting lethar-
gic courtship and locomotory movements. Males
in these species waved far less than U. pugilator
and it appeared that waving depended more on
the actual sight of the female in these species.
Uca pugilator, in contrast, show anatomical af-
finities to the more advanced species (Crane,
Table 17. The Mean Number per Minute and
Standard Deviation of Sounds Produced by 10
Male Uca pugilator at Night Before and During
Exposure to Light
Group of
Minutes
Minutes
Ten Crabs1
1, 2
3,4
t- Value
Experimental
Mean: 21.5
5.4
Crabs
SD: 8.4
4.5
7.55*
Control
Crabs
Mean: 19.2
17.4
0.79
SD 6.2
8.1
lExperimental crabs: Two minutes of darkness fol-
lowed by two minutes of light. Control crabs: Four
minutes of darkness.
*Means before and during light differ significantly at
the .01 level.
142
Zoologica: New York Zoological Society
[50: 12
1943.2) and devote much more time to waving
when females are not present. It was possible to
demonstrate that other stimuli such as sounds
from courting males caused male U. pugilator
to increase their waving rate (Table 4) . Gordon
(1958) reported that groups of male U. annu-
lipes often started to wave rapidly in the absence
of females. Similar behavior was observed in U.
pugilator. It is possible that in these species the
rapid waving of males is itself a stimulus that
other nearby males emulate.
C. Sound Production by Male U. pugnax and
Female U. pugilator
The stridulatory-like sounds from male U.
pugnax were produced when conspecific crabs
of either sex and female U. pugilator were intro-
duced into the male’s burrow. The fact that
males of this species also produce rapping sounds
similar to those used in courtship by U. pugilator
would seem to indicate that such sounds (stridu-
latory) are not involved in courtship. In addi-
tion, stridulatory sounds are employed by many
other species of decapods as aggressive signals
(Guinot-Dumortier & Dumortier, 1960). It is
hypothesized that stridulatory-like sounds pro-
duced by U. pugnax function as warning to an
intruder that a burrow is occupied, as has been
postulated by Crane (1941.2) for Ocypode.
Sound production by female fiddler crabs has
been observed in U. tangeri by Von Hagen
( 1962) and the sounds were produced in aggres-
sive interactions between females. It is probable
that the sounds produced by female U. pugilator
have a similar function although they may also
be involved in other behavior patterns.
D. Courtship Interactions Between Males
and Females
The introduction experiments involving fe-
males placed before the burrows of male U. pug-
ilator showed that the initial presence of a female
would cause males to increase their waving rate
more than twofold (Table 1). A moving female
was capable of eliciting even more rapid waving
movements (Table 2) . Non-moving females lost
the ability to induce waving in males within 30
seconds and were attacked by 13 of the 30 males
tested. The males abruptly ceased their attacks
and began waving when females were moved
during the experimental period. These experi-
ments demonstrated that lateral movements by
the female stimulated the males to wave for pro-
longed periods (over 30 seconds). Von Hagen
(1962) previously showed that in addition to
lateral movement, vertical movements of fe-
males and models stimulated waving in U. tan-
geri.
The waving responses of male U. pugilator to
females of different species before, during and
after they were moved before their burrows were
similar to the responses to conspecific females
under the same experimental conditions (Table
3). Burkenroad (1947) observed that U. pugi-
lator waved at Sesarma sp. which wandered into
the colony. Von Hagen (1962) found that U.
tangeri would wave at Carcinus maenus and
Pachygrapsus marmoratus. It appears that males
of U. pugilator and U. tangeri cannot discrimi-
nate between females of different Uca species,
and in fact treat any crab approximating their
size but lacking the major cheliped, as females.
These results support the hypothesis that selec-
tion of a conspecific mate must be accomplished
by the female, at least during the initial stages
of courtship. However, experiments which dem-
onstrate a selective response by females for con-
specific males are lacking for any species of Uca.
The courtship behavior of male U. pugilator
during the day changed according to the distance
of the female from the male’s burrow (Text-fig.
6). At distances of 5 to 10 cm. between the fe-
male and the burrow, more waves than sounds
were produced by the males. At 5 cm., the num-
ber of sounds increased and at 2.5 cm. many
more sounds than waves were produced. Obser-
vations of courtship interactions when the fe-
males were farther than 10 cm. from the burrow
showed that only waving took place. It follows
then that the initial stages of courtship by the
male during the day consist of waving display.
Sound production occurs only after the female
has come closer to the burrow. The data from
Table 6-A suggested that the relative amount
of waving and sound production was modified
by the pace at which the female approached the
male’s burrow. A slowly approaching female
would remain farther from the male’s burrow
for a longer period of time and the male would
tend to produce a greater number of waves.
Sound production by the male could be observed
just outside the burrow entrance after the slow
approach of the female. If the female ap-
proached quickly, fewer waves were produced
and sound production was confined to the inside
of the burrow. Burkenroad’s (1947) contention
that diurnal sound production occurred only
when the male was inside his burrow would seem
to apply only when the female approached
quickly.
Introductions of males and females into the
burrows of a male at night caused the rate of
sound production by the test males almost to
double (Table 9). Sounds were produced at
comparable rates immediately after similar in-
troduction tests during the day. These data indi-
1965]
Salmon: Waving Display and Sound Production in Uca pugilator
143
cate that sexual discrimination inside the burrow
does not take place. Under natural conditions
sexual discrimination appears to depend on cues
which occur earlier on the beach surface. Several
workers (Burkenroad, 1947; Altevogt, 1957;
Salmon & Stout, 1962) have demonstrated that
during the day sexual discrimination by the male
is based on visual cues, i.e., the presence or ab-
sence of the major cheliped. Field observations
in this study showed that sexual discrimination
at night depended on the intensity of contact be-
tween male and intruding crab. Gentle tactile
stimulation elicited courtship behavior consisting
of higher rates of sound production, movement
into the burrow and leg flicking movements by
the male. More intense contact resulted in the
cessation of sound production and aggressive
behavior. Gentle tactile stimulation with a var-
iety of objects and with a leaf of Spartina (Table
8) also elicited courtship behavior from the
males, which indicates that chemical cues are
secondarily involved (if at all) in the initial
stages of nocturnal courtship and in sexual dis-
crimination.
Burkenroad (1947) stated that sounds pro-
duced by the male after a female approached his
burrow during the day differed from sounds pro-
duced by lone males at night only in that the
intersound intervals were smaller. But he did not
physically analyze the sounds for other differ-
ences. When sounds produced by males at night,
before and during introduction experiments,
were analyzed, the pulse composition was more
variable (Table 10) and the interpulse intervals
were shorter during the introduction (Table 11
and Plate III). It is likely that these changes
would also characterize sounds produced by
males when approached by females during the
day, since in both cases the sounds emanate from
males that are sexually stimulated. It would be of
interest to determine if U. pugilator is capable
of discriminating between sounds of various
pulse composition. Since U. tangeri normally
produces two types of sounds (long and short
whirls) which differ in their pulse number, it is
quite likely that these differences can be detected
and may have communicative value in both U.
tangeri and U. pugilator.
E. Effect of Light and Temperature on
Courtship Behavior
The behavior of males isolated in screen pens
(Table 16) and the results of diel recordings
(Text-fig. 7) confirmed Burkenroad’s (1947)
original hypothesis that waving was confined to
diurnal and sound production to nocturnal peri-
ods. The tallies of per minute sound production
by individual males at night (Table 7) indicated
that the sounds were produced almost continu-
ously, although there were occasional periods
from a few seconds to five minutes when sound
production stopped temporarily. The experi-
ments in which males were covered with light-
proof boxes (Text-fig. 7) and exposed to arti-
ficial light at night (Table 17) showed that these
changes in courtship behavior were controlled
and synchronized principally by changes in the
daily light cycle. The response of males to sound
playbacks of 56 sounds per minute was also con-
trolled by light. During the day, the response of
males consisted of an increase in waving rate
(Table 4) but when covered with a light-proof
box, of sound production (Table 15).
An influence of temperature on rate of wav-
ing has been reported by Von Hagen ( 1962) for
U. tangeri. There was a gradual and linear in-
crease in the average rate of “spontaneous” wav-
ing (waving in the absence of females) from 2
to 14 waves per 30 seconds at body temperatures
of 17° to 44° C. These results indicate that an
adequate description of waving rate in any Uca
species must include data on temperature condi-
tions. Similar measurements were not made in
U. pugilator, as it was not possible to control for
the influence of females or for sound production
from neighboring males on the waving rates of
individual males. Attempts to control for possi-
ble visual stimuli by surrounding a male’s bur-
row with an opaque screen resulted in complete
inhibition of waving. Von Hagen (1962) found
that at any one temperature the number of waves
and short whirl sounds produced by the males
for a 10-second period were similar. His mea-
surements ranged from 1 .9 sounds and 2.0 waves
per 10 seconds at 21° C. to 4.4 sounds and 4.5
waves at 38° C. The average rate of sound pro-
duction by lone male U. pugilator at 20° C. was
18.5 sounds per minute or about 3 sounds per 10
seconds. It is possible that the slower rate of
sound production by U. tangeri at temperatures
comparable with U. pugilator is an adaptation to
the higher daily temperatures in Andalusia than
at Beaufort. The data in Text-fig. 4 show that
there was a correlation between higher tempera-
tures and an increase in the mean rate of sound
production by males at night. Since an increase
and decrease in temperature from one day to the
next was correlated with similar changes in rate
of sound production, it is likely that temperature
casually affected rates of sound production. Field
observations revealed that at colder temperatures
the cheliped of a sound-producing male was
raised and lowered much more slowly. It would
be expected therefore that the time between suc-
cessive contacts between the claw and the sub-
strate (the interpulse interval) and the total
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amount of time involved in the production of a
single sound (the sound duration) would in-
crease. The results of physical analysis of sounds
produced at lower temperatures showed that
these were the principal changes that occurred
(Text-fig. 5 and Plate II).
F. Chorusing Behavior
Alexander (1960) defined chorusing in orthop-
terans and cicadids as the tendency for . .
neighboring males in colonies to synchronize,
alternate or combine in some unusual fashion,
the individual phrases or pulses of their songs.”
He stated that the simplest kind of chorusing be-
havior consisted merely in the starting of song
by large numbers of individuals in a colony in
response to hearing other individuals start.
There is evidence for chorusing behavior be-
tween males of U. pugilator under natural and
under experimental conditions. The rate of
sound production by groups of males at night
was observed to increase when a nearby male,
probably in response to tactile stimulation by
another crab, increased his rate of sound produc-
tion. In addition, previously silent males in the
vicinity began to produce sounds. Sound play-
backs of 56 sounds per minute induced sound
production more quickly in males previously
frightened into silence (Table 13). Males pro-
ducing sounds before the playback responded
preferentially to sound playbacks at this rate by
increasing their own rate of sound production
during the playback (Table 12). Males also
showed a significant increase in rate of sound
production during the playback of 24 sounds per
minute. The range in increase of sound produc-
tion rate between control and experimental pe-
riods during this playback was 4.7 sounds per
minute, only 1.6 sounds per minute over the
range of increase during the control test when no
playback was made. It is possible that the in-
crease during the playback of 24 sounds per min-
ute was a chance phenomenon. Further experi-
ments are needed to clarify that problem.
Although it was possible to demonstrate in-
duction of sound production in silent males as
well as an increase in rate of sound production
during certain playbacks, there is no evidence
for more complex chorusing behavior involving
synchrony or alternation of sounds between
males. Three-minute playbacks at rates of 16 and
24 sounds per minute, comparable in rate to
many males in the field, did not influence the
mean rate of sound production by the males
tested (Table 14). In addition, synchrony or
alternation of sounds between neighboring males
was never observed in the field.
When sounds at a rate of 56 per minute were
played back to males during the day, courtship
behavior was also influenced. Males previously
frightened into their burrows responded to the
playback by coming to the surface faster than
males which received no playback (Table 5).
Both Dembowski (1925) and Von Hagen (1962)
have reported that U. pugilator and U. tangeri
in their burrows responded similarly to sound
production by other crabs in the field. Those
males already on the surface (as well as those
induced to come out of their burrows) responded
to playbacks by increasing their rate of waving
(Table 4). The results parallel those of sound
playbacks at night, as in both cases there is an
increase in the rate at which courtship move-
ments are produced as well as in the number of
males exhibiting courtship behavior.
There is some indication that visual stimuli
in addition to sounds are involved in chorusing
behavior. Gordon’s (1958) report of synchro-
nous claw waving in U. annuli pes between groups
of males in an area within the colony (also ob-
served in U. pugilator ) indicates that the males
can be stimulated to wave faster even when no
females are present. Presumably the stimulus in-
volved here is one or more males waving faster
than others. But experimental evidence to sup-
port this hypothesis is lacking.
G. Theoretical Aspects
Courtship in U. pugilator appears to be com-
posed of at least two phases. The “calling”
phase consisted of waving behavior during the
day, and sound production at night, both ex-
hibited by males in the absence of females. The
“courting” phase, in contrast, was released and
maintained in males only by the presence of the
female. During the day the courting phase con-
sisted of rapid waving when the female ap-
proached and rapid sound production starting
just before and after she entered the male’s bur-
row. At night the courting phase consisted of
rapid sound production accompanied by leg
flicking movements, released in the male by tac-
tile stimuli from the female.
There is strong evidence that in U. pugilator
waving is primarily involved in courtship. In-
truding females cause an increase in waving rate
while intruding males cause previously waving
males to cease waving and defend their burrows.
It is probable that waving serves at least three
functions: orienting the female to the male’s
burrow, stimulating her sexually and presenting
cues which identify conspecific males.
The sounds produced by males at night dur-
ing the calling phase are almost certainly di-
rected at the female. Both sexes initiate sound
production at rapid rates when they touch a resi-
1965]
Salmon: Waving Display and Sound Production in Uca pugilator
145
dent male. Sexual discrimination at night appears
to depend upon behavioral cues which occur after
this initial contact. The hypothesis that sounds are
attractive to the female is supported by experi-
ments of Von Hagen (1962). In two cases he was
able to induce female U. tangeri which had
paused near a male’s burrow, to enter the burrow
when artificial sounds simulating those of males
were played back. The negative results in sound
playback experiments to female U. pugilator in
this study may be due to a number of factors,
i.e., there was no way to determine before the ex-
periment if the females had copulated previ-
ously. In addition, they were tested almost im-
mediately after being subjected to the trauma
of handling and were only given one minute to
respond to the playback. Better-designed experi-
ments with females need to be conducted, pref-
erably in the field and with females raised in the
laboratory or isolated from males immediately
after hibernation. Females may respond to
sounds produced by males at night in several
ways. It may be possible for females to orient
directionally to the sound-producing male by
comparing the intensity of vibrations perceived
on the side of the body nearest the male with
vibration intensities on the other side. The sounds
might also induce more rapid wandering activity
by receptive females which, in dense colonies of
males, would increase the probability of contact
with the male.
There is considerable variability in both the
rate at which sounds are produced by U. pugi-
lator at any given temperature (Text-fig. 4) and
in the intervals between successive sounds in a
series. Alexander (1960, 1962) has pointed out
that the evolution of precise temporal song pat-
terns in male orthopterans is selected for when
more than one sound-producing species lives in
a particular area. The variability in calling
sounds of U. pugilator can therefore be attrib-
uted to its isolation from other species which
utilize sounds in a calling phase. There is some
evidence from introduction experiments that
rapping sounds are produced by courting male
U. pugnax but only when the males are deep
inside their burrows. Under these conditions
acoustical interference with neighboring male
crabs would be minimal. Although there is con-
siderable overlap in their ranges, the two species
are found in different habitats. Usually, U. pug-
nax is found in muddy areas and U. pugilator on
sandy beaches. Teal (1958) has demonstrated
that larvae of U. pugnax and U. pugilator tend
to select the substrate in which the adults are
found. Miller (1961) found that the mouth parts
of adult U. pugnax and U. pugilator show spe-
cies-specific modifications of the spoon-tipped
hairs used in feeding which enables the adults
to feed most efficiently on the substrate pre-
ferred by the larva.
The evolution of specific song patterns of male
orthopterans develops simultaneously with a cor-
responding specificity in response to the male by
the female (Alexander, 1960). Walker (1957)
has shown that in certain tree crickets (Oecan-
thinae), the females respond preferentially to
the pulse rate of conspecific males. Since the
pulse rate changes with temperature, a positive
response by the female occurs only if her body
temperature is approximately that of the male.
In these insects the pulse rates increase regularly
at higher temperatures and with little deviation
from the mean. The rate of sound production
and the intervals between sounds produced by
U. pugilator are variable at temperatures en-
countered in the field. It is likely that the female
shows little specificity for these properties in the
calling sounds of the male. In addition, the type
of chorusing behavior found in U. pugilator in
which neighboring males can stimulate each
other to produce sounds at night is characteristic
of orthopteran species in which there is no pre-
cise rhythm in the calling song (Alexander,
1960).
At least eight species of Uca are known to pro-
duce sounds during their day-time courtship.
None of the six tropical American rapping spec-
ies exhibit courtship behavior or produce court-
ship sounds at night (Crane, personal communi-
cation). On the basis of present evidence it ap-
pears that only in U. pugilator and U. tangeri,
which extend their ranges into temperate areas,
does nocturnal courtship occur. It seems logical
to postulate that in temperate regions, climatic
conditions limit the periods when successful re-
production can take place and that any mecha-
nism which increases the rate of fertilization
would be of great selective value to a temperate
species. The incorporation of acoustical signals
into nocturnal courtship of these two species en-
ables reproductive activities to occur at night,
independent of visual cues such as waving, which
are effective only during the day. The results of
field observations during the breeding season in-
dicate that climate does not directly affect the
reproductive activities of adult U. pugilator and
U. tangeri. Giese (1959) stated that the life
cycles of marine invertebrates were usually
timed so that the environment favored optimal
survival of the young. Boolootian et al. (1959),
in their studies of the reproductive cycles of five
west coast species of crabs, found that in three
of the species studied reproductive activities of
the adults were correlated with the availability
of food during the larval stages. It would be in-
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[50: 12
teresting to learn if the reproductive activities of
temperate Uca also showed this correlation.
Male U. tangeri undergo a wandering phase
and migrate to the entrance of the female’s bur-
row where sound production and copulation
may follow. Von Hagen (1961, 1962) has sug-
gested a possible explanation for this courtship
pattern. Customary claw harvests by local in-
habitants strip many males of their major cheli-
peds. As a result many males possess a small
claw and a regenerating major cheliped, much
reduced in size. It may be that males lacking
the major cheliped cannot produce sounds of
sufficient intensity to communicate to females
from a distance. Migration to the female’s bur-
row could be an adaption to bring the sexes
closer together before sound production occurs.
In addition, males of this species are able to pro-
duce sounds without the large major cheliped.
These unusual reproductive patterns for a broad
front fiddler crab may be, as Von Hagen (1961,
1962) has suggested, a cultural product of man.
In contrast, courting males of U. pugilator
confine their activities to the burrow and the area
surrounding the entrance, which they defend
against intruders. It is likely that, as is the case
in territorial sound-producing male orthopterans,
the male’s waving during the day and his sounds
at night function to attract the female into the
male’s territory where copulation takes place.
Burkenroad (1947) observed a total of eleven
mating couples at night near the water’s edge
during low tide, a considerable distance from
the sound-producing males found in the upper
portion of the beach. But Crane (personal com-
munication) believes that in such cases insertion
of the male abdominal appendages into the fe-
male’s genital aperature probably does not take
place.
Crane (1957) pointed out that in the more
advanced species of broad fronts much more
time was devoted to waving display. But she did
not present any evidence to support her conclu-
sion or suggest any causal mechanisms responsi-
ble for this change in behavior. The results of
experiments reported here have shown that
courtship in male U. pugilator is augmented by
sound stimuli emanating from other males both
at night and during the day. Synchronous claw
waving by groups of males during the day, in
the absence of sounds, indicate that visual stim-
uli may also augment courtship activity. It is
postulated that sounds and visual stimuli from
male U. pugilator are responsible for the greater
time devoted to courtship activity by neighbor-
ing males. In U. pugnax and U. minax, these
cues do not appear to operate and courtship by
males appears to depend more strongly on the
actual sight of the female. Alexander (1960)
has found in the orthopterans and cicadids that
although the basic function of the male’s sounds
is to attract a receptive female, the “. . . sounds
actually have a greater variety of effects upon
other males which hear them than upon fe-
males.” He attributed these “side” effects to se-
lection for chorusing behavior patterns which
enhance the primary function of bringing the
sexes together through adjustments in the social
organization of the species.
The disagreement in the literature concerning
the function of waving is due in part to the fact
that the majority of the studies have been purely
descriptive. While a great deal of valuable infor-
mation has been contributed by such studies, few
authors have employed experimental techniques
or quantified their observations. As a result most
of what is known about courtship in Uca is based
upon subjective interpretation of field observa-
tions. In addition, most of the studies have dealt
only with waving, the initial stage in courtship,
to the exclusion of subsequent courtship inter-
actions inside the burrow which might also yield
important clues to relationships between species.
More extensive experimental studies on the be-
havior of each species are needed before gen-
eralizations can be applied with a degree of cer-
tainty. Indeed, generalizing at this point may risk
masking a variety of behavioral adaptations
evolved within each species during their court-
ship.
V. Summary
1. The role of waving behavior and sound
production in the courtship behavior of Uca
pugilator was studied at Beaufort, North Caro-
lina, during the summers of 1962 and 1963.
Comparisons were made between the waving
displays of U. pugilator and two local species,
U. minax and U. pugnax , and between the acous-
tical behavior of U. pugilator and the European
species, U . tangeri.
2. When no female was present, waving be-
havior by male U. pugilator was confined to
males with burrows during diurnal low tides. At
night, sound production occurred during low
tides and almost continuously by lone males pos-
sessing burrows. When light-proof boxes were
placed over the males, sounds were produced
during the day. Conversely, exposure to artificial
light at night caused sound production by males
to stop within 30 seconds.
3. Waving rates of male U. pugilator more
than doubled when they were presented with
conspecific females or females of different Uca
species. When a female approached within 7.5
cm. of a male’s burrow the male began to pro-
1965]
Salmon: Waving Display and Sound Production in Uca pugilator
147
duce sounds between consecutive waves. If the
female followed the male into his burrow the
male produced many sounds at a rapid rate.
When a sound-producing male was touched
by a female at night, his rate of sound production
nearly doubled and equaled the rate of which
sounds were produced during the day. Gentle
tactile stimulation with a variety of inanimate
objects elicited the same response from the test
male. When touched by an intruding male at
night, the resident male at first increased his rate
of sound production, but subsequently stopped
sound production and defended his burrow
against the intruder.
4. Sound playback experiments to determine
if females were attracted to sounds produced
negative results. Playbacks to males demon-
strated that they would at night increase their
rate of sound production when the playback
consisted of 56 sounds per minute, the fastest
rate recorded in the field. Playbacks at slower
rates did not affect the rate of sound production
by the test males. Playbacks of 56 sounds per
minute also induced males previously frightened
into silence to produce sounds faster than con-
trol males not exposed to playback. During the
day playbacks induced males in their burrows to
come to the surface and those males already on
the surface to wave at faster rates. The signifi-
cance of these responses by the males to play-
backs was discussed and the results compared
to certain types of chorusing behavior shown
by male orthopterans and cicadids.
5. Sounds produced by male U. pugilator be-
fore and after contact with a female were physi-
cally analyzed. It was found that the sounds
after contact with the female were produced at
greater rates, had smaller interpulse intervals,
had a more variable pulse content per sound but
contained about the same mean number of pulses
per sound.
6. The rate of sound production in the field
by lone male U. pugilator at night was found to
increase gradually with higher temperatures. But
there was a considerable variation in both the
rate at which individual males produced sounds
and in the intersound intervals at any one tem-
perature. The theoretical significance of this
variability was discussed with reference to the
specificity of the female to sounds of the male
and was attributed to the ecological isolation of
U. pugilator from other sound-producing spe-
cies.
7. The waving display of U. pugilator differed
from U. pugnax and U. minax in the duration
of single waving movements, in the movements
of the ambulatories and the minor chelae and in
body movements which accompanied each wave.
In addition, waving by U. pugilator occurred
much more frequently than in the other two
species and even when no female was present.
8. Introduction of other Uca into the burrows
of male U. pugnax during the day resulted in the
production of stridulatory-like sounds. In two
cases, rapping sounds similar but not identical
to those of U. pugilator were heard. It was hypo-
thesized that the stridulatory-like sounds were
involved in aggressive behavior while the rap-
ping sounds were involved in courtship behavior.
No sounds were detected at night from male
U. pugnax or U. minax.
Burrow-owning female U. pugilator produced
sounds in response to intruding females by alter-
nately striking the ground with their two minor
chelipeds. It was hypothesized that these sounds
were also used as aggressive signals.
9. It was hypothesized that the presence of
nocturnal courtship and sound production, in
addition to diurnal courtship exhibited by most
Uca, was an adaptation of temperate species
which enabled faster completion of reproductive
activities during the brief periods when climatic
conditions were favorable for the survival of the
young. The ecological factors which account for
the differences between nocturnal and acoustical
behavior of U. pugilator and U . tangeri were
discussed.
VI. Acknowledgments
Special thanks are due Dr. Howard E. Winn
for support of this work through his grants
(U. S. P. H. S. NB-03241, NR104-489) , for ad-
vice and guidance throughout the study and for
criticism of the manuscript. Dr. John F. Stout
suggested the initial studies of Uca behavior
which led to this work. Dr. Edwin Cox and Dr.
Anthony R. Picciolo aided in the techniques used
to analyze the data. The generous cooperation
of the faculty and staff of the Duke Marine Lab-
oratory is especially appreciated. Dr. Maximo
J. Cerame-Vivas made available his transistor
tape recorder used in some of the experiments.
Mr. Richard Heard was an invaluable guide in
the location of new colonies. Mr. David E.
Schneider took most of the photographs and
helped in their processing. Miss June Harrigan
assisted in some of the experiments. Mrs. Erica
Kohlmeyer helped in the translation of some of
the German papers. Miss Jocelyn Crane, through
her papers and in personal conversation, was a
continuing source of ideas in the interpretation
of Uca behavior. Mr. Walter L. Salmon helped
in preparing the manuscript for publication, and
provided additional criticism.
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VII. References
Alexander, R. D.
1960. Sound communication in Orthoptera and
Cicadidae. In W. E. Lanyon and W. N.
Tavolga, (ed.). Animal sounds and com-
munication. A.I.B.S.
1962. Evolutionary change in cricket acoustical
communication. Evolution, 26: 442-467.
Aurivillius, C. W. S.
1893. Beziehunger der sinnesorgane amphibi-
scher Dekapoden zur Lebensweise und
Anthmung. Nova Acta Soc. Usal. (3),
16: 1-48.
Alcock, A.
1892. On the habits of Gelasimus annulipes.
Ann. Mag. Nat. Hist., 6: 415.
1902. A naturalist in Indian seas. London.
Altevogt, R.
1955.1 Some studies on two species of Indian
fiddler crabs, Uca marionis nitidus (Dana)
and U. annulipes (Latr.). Jour. Bombay
Natural History Soc., 52: 700-716.
1955.2 Beobachtungen und Untersuchungen an
indischen Winkerkrabben. Z. Morph, u.
Okol. Tiere, 44: 501-522.
1957. Untersuchungen zur Biologie, Okologie
und Physiologie indischer Winkerkrabben.
Z. Morph, u. Okol. Tiere, 46: 1-110.
1959. Okologische und ethologische Studien an
Europas einziger Winkerkrabbe Uca
tangeri Eydoux. Z. Morph, u. Okol. Tiere,
48: 123-146.
1962. Akustische Epiphanomene im Sozialver-
halten von Uca tangeri in Sudspanien.
Sonderdruch aus Verhandlungen der
Deutschen Zoologischen Gesellschaft in
Wien, 22: 309-315.
Beebe, W.
1928. Beneath tropic seas. G. P. Putnam’s Sons.
N. Y.
Boolootian, R. A., A. C. Giese,
A. Formanfarmaian & J. Tucker
1959. Reproductive cycles of five west coast spe-
cies of crabs. Physiol. Zoology, 32: 213-
220.
Burkenroad, M. D.
1947. Production of sound by the fiddler crab,
Uca pugilator Bose, with remarks on its
nocturnal and mating behavior. Ecology,
28: 458-461.
Crane, J.
1941.1 Eastern Pacific Expeditions of the New
York Zoological Society. XXVI. Crabs of
the genus Uca from the west coast of
Central America. Zoologica, 26: 145-207.
1941.2 Eastern Pacific Expeditions of the New
York Zoological Society. XXIX. On the
growth and ecology of Brachyuran crabs
of the genus Ocypode. Zoologica, 26: 297-
310.
1943.1 Crabs of the genus Uca from Venezuela.
Zoologica, 28: 33-44.
1943.2 Display, breeding and relationships of
fiddler crabs (Brachyura, genus Uca) in
the northeastern United States. Zoologica,
28: 217-223.
1957. Basic patterns of display in fiddler crabs
(Ocypodidae, genus Uca). Zoologica, 42:
68-82.
1958. Aspects of social behavior in fiddler crabs,
with special reference to Uca maracoani
(Latreille). Zoologica, 43: 113-130.
Darwin, C.
1871. The descent of man. Modern Library,
N. Y.
Dembowski, J.
1925. On the “speech” of the fiddler crab, Uca
pugilator. Trav. Inst. Nenchi, Vol. Ill, No.
48.
Gray, E. H.
1942. Ecological and life history aspects of the
red-jointed fiddler crab, Uca minax (Le
Conte), region of Solomons Islands, Mary-
land. Publ. No. 51, Chesapeake Biol. Lab.,
1-20.
Gordon, H. R. S.
1958. Synchronous claw-waving of fiddler crabs.
Animal Beh., 6: 238-241.
Guinot-Dumortier, D., & B. Dumortier
1959. La stridulation chez les crabes. Crusta-
ceana, 1: 117-155.
Giese, A. C.
1959. Annual reproductive cycles of marine in-
vertebrates. Ann. Rev. Physiol., 21: 547-
576.
Hagen, H. O. Von
1961. Nachtliche Aktivitat von Uca tangeri in
Sudspanien. Naturwiss., 48: 140.
1962. Frielandstudien zur Sexual- und Fortplan-
zungsbiologie von Uca tangeri in Andu-
lusien. Z. Morph, u. Okol. Tiere, 51:
611-725.
Hediger, H.
1933. Beobachtungen an der marokkanischen
Winkerkrabbe, Uca tangeri. (Eydoux).
Verh. Schweiz, naturf. Ges., 114: 388-389.
1934. Notes sur la biologie d’un crabe de l’em-
brouchure de l’oued Bou Regreg Uca
tangeri (Eydoux). Bull. Soc. Sci. Nat.
Maroc., 8: 254-259.
Johnson, M. E., & H. J. Snook
1927. Seashore animals of the Pacific coast.
Macmillan, N. Y.
Matthews, L. H.
1930. Notes on the fiddler-crab, Uca leptodac-
tyla, Rathbun. Ann. Mag. Nat. Hist., (Ser.
10) 5: 659-663.
1965]
Salmon: Waving Display and Sound Production in Uca pugilator
149
Miller, D. C.
1961. The feeding mechanisms of fiddler crabs,
with ecological considerations of feeding
adaptations. Zoologica, 46: 89-100.
Muller, F.
1869. Facts and arguments for Darwin. London.
Pearse, A. S.
1912. The habits of fiddler-crabs. Philippine J.
Sci., (Sec. D) 7: 113-133.
1914.1 On the habits of Uca pugnax (Smith) and
U. pugilator (Bose). Trans. Wis. Acad.
Sci., 17: 791-802.
1914.2 Habits of fiddler crabs. Ann. Rep. Smith.
Inst. 1913 (1914): 415-427.
Peters, H. M.
1955. Die Winkgebarde von Uca und Minuca
(Brachyura) in vergleichend-ethologis-
cher, okologischer und morphologisch-
anatomischer Betrachtung. Z. Morph, u.
Okol. Tiere, 43: 425-500.
Rathbun, M. J.
1914. New genera and species of American
Brachyrhynchous crabs. Proc. U. S. Nat.
Mus., 47: 117-229.
Salmon, M., & J. F. Stout
1962. Sexual discrimination and sound produc-
tion in Uca pugilator Bose. Zoologica, 47:
15-20.
SCHONE, H., & H. SCHONE
1963. Balz und andere Verhaltensweisen der
Mangrovekrabbe Goniopsis cruentata
Latr. und das Winkverhalten der eulitoren
Brachyuren. Z. fur Tierpsychol., 20: 641-
656.
Swartz, B., & S. R. Safir
1915. The natural history and behavior of the
fiddler crab. Brooklyn Inst. Arts and Sci.,
Cold Spring Harbor Monographs, 8 : 1-24.
Symonds, C. T.
1920. Notes on certain shore crabs. Spolia
Zeylan. Colombo, 11: 306-313.
Tashian, R. E., & F. J. Vernberg
1958. The specific distinctness of the fiddler
crabs Uca pugnax (Smith) and Uca rapax
(Smith) at their zone of overlap in north-
eastern Florida. Zoologica, 43: 89-92.
Teal, J. M.
1958. Distribution of fiddler crabs in Georgia
salt marshes. Ecology, 39: 185-193.
Verway, J.
1930. Einiges uber die Biologie ost-indischer
Mangrovekrabben. Treubia, 12: 169-261.
Walker, T. J.
1957. Specificity in the response of female tree
crickets (Orthoptera, Gryllidae, Oecan-
thinae) to calling songs of the males. Ann.
Ent. Soc. Amer. 50: 626-636.
150
Zoologica: New York Zoological Society
[50: 12: 1965]
EXPLANATION OF THE PLATES
Plate I
Fig. 1. Photograph of a male in position and pro-
ducing sounds at night just outside the
entrance to his burrow.
Fig. 2. The burrow entrance (left) and adjacent
impression (right) left in the sand by the
base of the major chela of another male
which had been producing sounds for
three previous hours.
Plate II
Fig. 3. Sonogram of one sound produced by a
male Uca pugilator at 14° C. (A), 18.5°
C. (B) and 24° C. (C).
Plate III
Fig. 4. Sonogram of two sounds produced at night
by a male Uca pugilator before (A) and
during (B) introduction of a conspecific
female into his burrow, illustrating the re-
duction in the interpulse intervals of
sounds produced during the introduction.
Pointed lines in A are the same length as
those in B, but in B they extend farther
into adjacent pulses.
Plate IV
Fig. 5. Sonogram of a sound produced by a male
Uca pugnax during the introduction of a
conspecific male (A) and by a female U.
pugilator during the introduction of a con-
specific female (B). Both introductions
were made into the burrow of the test
crabs during the day.
Plate V
Fig. 6. A male Uca pugilator waving at night.
The male had previously been producing
sounds but started to wave ten seconds
after exposure to a 150 watt incandescent
light source.
SALMON
PLATE I
FIG. 1
FIG. 2
WAVING DISPLAY AND SOUND PRODUCTION IN THE COURTSHIP BEHAVIOR
OF UCA PUGILATOR. WITH COMPARISONS TO U. MINAX AND U. PUGNAX
SALMON
PLATE II
CO
gjj
-J
o
>
o
o
MILLISECONDS
FIG. 3
WAVING DISPLAY AND SOUND PRODUCTION IN THE COURTSHIP BEHAVIOR
OF UCA PUGILATOR. WITH COMPARISONS TO U. MINAX AND U. PUGNAX
MILLISECONDS
SALMON
KILOCYCLES
PLATE III
FIG. 4
WAVING DISPLAY AND SOUND PRODUCTION IN THE COURTSHIP BEHAVIOR
OF UCA PUGILATOR. WITH COMPARISONS TO U. MINAX AND U. PUGNAX
KILOCYCLES
SALMON
6 '
5 '
4 ■
3 -
2 -
6 -
5 '
4 -
3 '
2 -
S '
B
PLATE IV
f
i
I
i *
1 1
i :
r
*_
*
I
k
§
i if
i t
- *.
l
i
1 If
• h * ■{
| !
! i
• t 1 li
1 \
* h t k i
1 if i E 1
1 *
f ‘ [
5 ft,*
1 ! ‘ u
\ ? 1 1
£ * f
i£ t
! * • \
200 400 600 800 SOOO S200 1400
MILLISECONDS
FIG. 5
WAVING DISPLAY AND SOUND PRODUCTION IN THE COURTSHIP BEHAVIOR
OF UCA PUGILATOR. WITH COMPARISONS TO U. MINAX AND U. PUGNAX
SALMON
PLATE V
FIG. 6
WAVING DISPLAY AND SOUND PRODUCTION IN THE COURTSHIP BEHAVIOR
OF UCA PUGILATOR. WITH COMPARISONS TO U. MINAX AND U. PUGNAX
13
Genetics and Geography of Sex Determination in the Poeciliid Fish,
Xiphophorus maculatus
Klaus D. Kallman
Genetics Laboratory of the New York Aquarium , American Museum of Natural History,
New York, N. Y. 10024
(Text-figure 1)
Contents
Page
Introduction 151
Materials and Methods 152
Results 154
A. Sex Determination in Laboratory Stocks
of Platyfish, Xiphophorus maculatus 154
B. The Sex Chromosome Mechanism of
Wild Populations of Xiphophorus maculatus 158
Belize River 158
New River 158
Rio Hondo Drainage 159
Lake Peten 161
Rio Usumacinta System 165
Rio Grijalva 167
Rio Coatzacoalcos 168
Discussion 169
Geography 169
Stability of Sex-Determining Mechanism . . 171
Crossing Over between Sex Chromosomes. . 172
Sex Reversal 173
Identity of the Y and “Z” Chromosomes ... 178
Evolution of Sex-Determining Mechanism in
Xiphophorus maculatus 181
Summary 186
Acknowledgments 187
Bibliography 188
Introduction
OF THE more than 140 known species of
poeciliid fishes, not more than two
dozen have been studied in any detail,
yet among these sex-determining mechanisms
have been discovered that are unique for ver-
tebrates (Gordon, 1947; C. Hubbs, 1964;
Hubbs & Hubbs, 1932; Kallman, 1962; Miller
& Schultz, 1959; Schroder, 1964; Schultz, 1961).
One species, Xiphophorus maculatus, the south-
ern platyfish, is thought to possess two sex-
determining systems. In certain strains, the fe-
males are the homogametic sex (XX 2 , XY $ ),
while in other strains the male is homogametic
(WY 2 , YY $ ). X. maculatus lives in the
Atlantic lowlands of Mexico, Guatemala and
British Honduras. It ranges from the rivers of
British Honduras westward across the Peten dis-
trict of Guatemala north to the Rio Jamapa,
near Veracruz, Mexico. It is absent from the
Yucatan peninsula (Text-fig. 1).
The WY-YY system of X. maculatus was
independently discovered by Bellamy (1922,
1928) and Gordon (1927) and subsequently
confirmed by Breider (1937, 1942) and Koss-
wig (1938). All four investigators worked with
domesticated stocks that had been imported
into Germany around the turn of the century
(Gordon, 1927). The location in Central
America from which the stocks originated was
never recorded, although many years later
Gordon (1952) was able to deduce that the
Belize River was the likely place of origin.
Gordon (1946, 1947, 1951 a, 1952) discovered
that the platyfish from three Mexican rivers,
the Rios Jamapa, Papaloapan and Coatzacoal-
cos, possessed a different sex-determining mech-
anism (XX 2 . XY $ ), and that a commercial
stock, allegedly from British Honduras, pos-
sessed the WY-YY system. Gordon (1950 a,
1951 a, 1952, 1954, 1957) also briefly reported
that females of the platyfish population of the
Rio Grijalva, Mexico, were homogametic, while
those from the New and Belize Rivers in British
Honduras were heterogametic. However, no
details were published. Gordon suggested that
the platyfish with opposing sex-determining
mechanisms were geographically isolated and
that fish living in rivers of British Honduras,
which flow into the Caribbean, possess the WY-
YY system, while fish inhabiting rivers that
drain into the Gulf of Mexico possess the
XX-XY type.
The XX-XY sex-determining mechanism has
also been found in Xiphophorus variatus by
Bellamy (1936), Kosswig (1937) and Rust
(1939) and in X. milled by Kallman (1965).
In other species, no sex-linked characters have
ever been detected, but interspecific crosses indi-
151
152
Zoologica: New York Zoological Society
[50: 13
cate that X. couchianus (Gordon & Smith, 1938;
Gordon, 1946; Zander, 1962) and perhaps X.
montezumae cortezi (Kosswig, 1959; Zander,
1965) have the XX-XY system. The swordtail,
X. hellerii, appears to have a polygenic sex-
determining mechanism (Gordon, 1957; Koss-
wig, 1964; Peters, 1964).
Fish (X. maculatus ) with different sex-deter-
mining systems are morphologically indistin-
guishable (Gordon & Gordon, 1954; Rosen,
1960) and mate readily not only with each other,
but also with X. variatus. The offspring are fully
fertile; the WY, WX and XX genotypes gen-
erally resulting in females, the XY and YY
conditions always in males, regardless from
which populations or species the X or Y chromo-
somes have been derived (Atz, 1959; Bellamy,
1936; Gordon, 1951 a, 1952; Gordon & Smith,
1938; Kosswig, 1935; Oktay, 1959 a, 1962).
Only a single cross in which the WY genotype
differentiated into males has been recorded
(Gordon, 1951 a). In this exceptional cross, the
Y chromosome had been derived from the Rio
Coatzacoalcos population of X. maculatus. This
cross has never been repeated and, therefore, it
is too early to speculate whether the “Y” from
this population has a stronger male determin-
ing potential than the Y chromosome from the
other populations. In an attempt to determine
more precisely the geographic distribution of
the two mechanisms, X. maculatus were col-
lected in several areas of Mexico, British Hon-
duras and Guatemala from which they had
never before been taken alive, and their sex
chromosome constitution was analyzed in the
laboratory.
Material and Methods
Identification of Sex. — In X. maculatus, as in
all other poeciliid fishes, the sexes are readily
distinguished by the shape of the anal fin. In
males this transforms into an intromittant organ,
the gonopodium, at the time of sexual maturity.
In extremely rare cases a fish may develop
without any gonad. Such fish superficially re-
semble females but possess a body shape differ-
ent from that of either sex. In cases of doubt,
however, sex was ascertained by autopsy.
Although more than 100,000 platyfish have
been raised at the Genetics Laboratory during
the last 25 years, not a single female (fish with
an ovary) has ever transformed into a male
(fish with a testis) or developed a gonopodium.
Consequently, in this paper a sex-reversed fish
is one that is functionally one sex, but geno-
typically the other.
Identification of Sex-determining Mecha-
nism. — Identification of the sex chromosome
constitution of wild-caught X. maculatus is
greatly facilitated by the existence of (1) labo-
ratory stocks of known sex chromosome con-
stitution and geographic origin and (2) a series
of phenotypically distinct, dominant multiple
alleles at a sex-linked locus. The chromosome
constitutions of the eight laboratory stocks are
listed in Table 1. The origin, sex ratio and sex-
linked pigment patterns of these strains are
described below. Of the five sex-linked ntacro-
melanophore alleles that Gordon (1948) de-
scribed from natural populations, four are in-
volved in the crosses reported in this paper:
N — Nigra: irregular black blotches or bands
along the flanks of the fish,
Sr — Stripe-sided: macromelanophores ar-
ranged in horizontal rows along the flanks,
Sp — Spot-sided: small, irregular spots of
macromelanophores along the flanks of fish,
Sd — Spotted-dorsal: irregular spots of mac-
romelanophores in the dorsal fin.
A difficulty occasionally encountered in rec-
ognizing these patterns is that the phenotypic
expression of the macromelanophore gene may
vary from zero penetrance to enhancement re-
sulting in a mild melanosis. However, long ex-
perience with our reference stocks has enabled
us to anticipate such difficulties. The Sd gene
of /p-163 A is only rarely expressed in inter-
strain platyfish hybrids, for example. In the Np
strain, the N, Sr and Sd alleles do not manifest
themselves in a small percentage of fish. Some
of the macromelanophore genes of the Lake
Peten fish also exhibit low penetrance in certain
hybrid combinations.
Diagnostic for the XX-XY sex-determining
mechanism are the following modes of inherit-
ance:
Father to son (pigment gene located on Y
chromosome) .
Father to daughter (pigment gene located on
X chromosome of father).
Maternal pigment pattern inherited by one-
half of daughters and one-half of sons (mother
heterozygous for pigment gene, located on X
chromosome) .
Indicative for the WY-YY sex-determining
system are the following modes of inheritance:
Mother to daughter (pigment gene located
on W chromosome).
Mother to son (pigment gene on Y chromo-
some of mother).
Paternal pigment pattern inherited by one-
half of daughters and one-half of sons (father
heterozygous for pigment gene, located on Y
chromosome) .
The last three types of inheritance, although
1965]
Kallman: Genetics and Geography of Sex Determination in Xiphophorus maculatus
153
inhabited by the platyfish, Xiphophorus maculatus.
Location of collecting stations: Belize — at mouth
of Belize River; San Estevan — 25 km. inland from
mouth of New River; Douglas and San Antonio —
on Rio Hondo, 32 and 40 km. inland (by air),
near western end of Lake Peten; Carmelita — 55 km.
NNW of Lake Peten, on tributary of Rio San
Pedro; Sebol — near the source of Rio de la Pasion.
Villahermosa is located at the tip of the arrow
pointing to Rio Grijalva.
consistent with the WY-YY system, cannot rule
out the possibility that one of the parents car-
ried an X chromosome; identical results are ex-
pected from the following three crosses: WY X
YY, WX X YY, WY X XY. WX and WY
females can be distinguished by crossing them
with XY males of the reference stocks in which
the X and Y chromosomes are marked by differ-
ent pigment genes. WY females give rise to two
types of male offspring, while WX females give
rise to only one class of sons. In addition the
olfspring of WX females occur in a 3 : 1 sex ratio.
In the absence of pigment markers, XX fe-
males can be distinguished from those carrying
a W chromosome by mating them with YY
males from reference stocks. XX females give
rise to all-male offspring, while W females pro-
duce males and females. Similarly, XY males
can be distinguished from YY males by mating
them with XX females of the reference strains,
since YY males sire all-male broods. A WY
female can be identified in still another, though
indirect, way. The female parent of any YY
son must have possessed the WY constitution.
Collecting Localities. — The following is a list
of stations from which platyfish were taken for
analysis of their sex chromosome constitution.
The dates and the expeditions responsible for
the collections are given in parentheses. The sta-
tions are listed from East to West (Text-fig. 1).
Belize River, British Honduras: just north of
the town of Belize ( 1949, Gordon, Fairweather,
Chaveria) .
New River, British Honduras: 1.6 km. north
of San Estevan (March, 1954, Gordon, Fair-
weather, Chaveria).
Rio Hondo : (a) east bank of the east branch
of Rio Hondo, opposite San Antonio, British
Honduras (March, 1954, Gordon, Fairweather,
Chaveria) .
154
Zoologica: New York Zoological Society
[50: 13
(b) small rill on east bank of Rio Hondo at
Douglas, about 8 km. downstream from the
previous location (March, 1963, Kallman,
Rosen, Dorion, Llarena).
(c) Aguada Corriental at Tikal, Guatemala:
(April, 1963, Kallman, Rosen). This aguada
belongs to the Rio Hondo drainage. Although
no outlet was observed during our visit, water
from this small pool overflows into a wooded,
swampy depression, El Bajo de Santa Fe, in the
rainy season, whence it flows through the Rio
Holrnul into the Rio Hondo.
Lake Peten, Guatemala: (a) near Flores at
the western end of Fake Peten ( 1954, Gordon).
(b) small stream running into the eastern
end of Fake Peten just south of Remate airstrip
(April, 1963, Kallman, Rosen).
Rio Usumacinta system: (a) Rio de la Pasion
— mouth of a small stream on the left bank
about 4 km. below Sebol, Guatemala (March,
1963, Kallman, Rosen, Camara).
(b) Rio de la Pasion — 200 meters inside a
small stream on right side of river, 8 km. below
Sebol, Guatemala (March, 1963, Kallman,
Rosen, Camara).
(c) Rio San Pedro de Martir — small stream
1 km. south of airstrip at Carmelita, Guatemala
(April, 1963, Kallman, Rosen).
Rio Grijalva, Mexico: collected near Villa-
hermosa (March, 1952, Gordon).
Rio Coatzacoalcos, Mexico: (1948, Gordon,
Atz, Wood).
Maintenance of Fish and Recording of Data.
— As soon as they are caught, all fish are placed
into plastic bags inside polystyrene containers.
Several hours later the original water is dis-
carded and replaced by clean water taken along
from the collecting station. At the same time
injured fish are discarded or preserved. To make
sure enough breeding fish reach the laboratory,
many more are collected than laboratory space
permitted us to use. Fish with macromelano-
phore patterns are selected, since the sex chro-
mosome constitution of such “marked” fish can
more readily be determined than that of the
wild type (unmarked). Sexes are not separated
until their arrival at the laboratory. Then the
fish from each station are counted and their
pigment pattern recorded. Fish that are not
completely healthy or have abrasions are placed
in a 0.6% sea salts solution with a few drops of
methylene blue, where they are kept until
recovery.
The fish are maintained according to the
method described by Gordon (1950 b). In addi-
tion, all fish less than two months old receive
a feeding of live brine shrimp nauplii every
afternoon. Under these conditions, platyfish be-
come sexually mature and are ready to mate at
the age of three months. When all offspring of a
particular cross are mature and exhibit their
respective pigment pattern, the data are recorded
in the central file of the Genetics Faboratory.
The fish are preserved in alcohol or formalin and
are thus available for future reference.
All wild-caught fish and their descendants and
the offspring of crosses between different refer-
ence stocks are identified by a pedigree number
given to them at birth or upon their arrival in
the laboratory. A second number following the
pedigree refers to individual fish, e.g. 1341 — 1
is female No. 1 of pedigree 1341 (the Fake
Peten fish). Numbers 1-10 are reserved for
females, numbers 11-20 for males. Wild-caught
fish of the Belize River, New River, Rio Hondo
( 1953 collection), Rio Grijalva and Rio Coatza-
coalcos are identified by the symbols Bp, Np,
Hp, Gp and Cp, respectively, followed by the
number of the particular individual. All crosses
pertaining to any one location have been listed
together in one or two tables and related crosses
have been grouped together wherever possible.
In several cases, a male was mated with two
females and all their offspring were given the
same pedigree number; one of these sibships
has then been called “a” and the other “b”.
Intrastrain crosses involving fish of the refer-
ence stocks have been summarized in Tables 2-5.
In the tables, fish belonging to any of the
reference stocks have been merely identified by
their code letters (Table 1). The chromosome
constitution of the wild-caught fish and their
descendants, as written in the tables, is the only
one that will adequately explain the results of
all crosses.
Results
A. Sex Determination in Faboratory Stocks
of Platyfish, Xiphophorus maculatus
New River Strain — Np: A single gravid fe-
male from the New River was the progenitor
of this strain. Among her offspring were fish
that carried the Sd, N or Sr alleles. All three
alleles have been retained through more than
1 1 generations of inbreeding by mating either
N females with Sd Sr males, Sd females with
N Sr males or Sr females with Sd N males
(Table 2). Sometimes the alleles were not ex-
pressed phenotypically, but in several instances
their presence was demonstrated through addi-
tional appropriate crosses. The sex ratio of 240
females to 276 males is in good agreement with
the expected 1 : 1 ratio. However, the possibility
that at least a few of the wild type, stripe-sided,
spotted-dorsal or nigra males were sex reversed
(WY $ ) or the result of crossing over cannot
1965]
Kallman: Genetics and Geography of Sex Determination in Xiphophorus maculatus
155
Table 1. Laboratory Stocks of the Platyfish, Xiphophorus maculatus*
Geographic
Origin
Year
Code
Sex Chromosome
Females
Constitution
Males
Generations
in the
Laboratory
New River
1954
Np
WY
YY
16
Rio Hondo
1954
Hp-1
WY
YY
15
Rio Hondo
1954
Hp-2
XX
XY
18
Rio Grijalva
1952
Gp
XX
XY
18
Rio Coatzacoalcos
1948
Cp
XX
XY
21
Rio Jamapa
1939
Jp 163 A
XX
XY
31
Rio Jamapa
1939
Jp 163 B
XX
XY
26
Rio Jamapa
1939
Jp 30
XX
XY
42
* Genetics Laboratory of the New York Zoological Society located at the American Museum of Natural History, as of
December, 1964.
be excluded. Only two fish among 240 female
offspring inherited the pigment pattern of the
female parent. Such mother-to-son inheritance
is characteristic for the WY-YY type of sex
determination. The W chromosome carries the
wild type allele; the N, Sr and Sd alleles are
located on the Y chromosomes.
One of the exceptional females died, but the
other was testcrossed with a wild type YY
(Hp-1) male.
Exceptional Np female Hp-1 male
X
wN YSr y+ r+
Fx (pedigree 1200)
Females: 44 N, 4 + ; Males: 44 Sr, 2 N
Since all but two of the nigra ( N ) offspring
were females and all striped (Sr) offspring
males, the exceptional N Sr female was probably
the result of a crossover. The four wild type
females of pedigree 1200 may have been the
result of nonexpressivity of the N gene, which
was very weakly expressed in the other females.
The two nigra males were not testcrossed; they
might have been exceptional WY males (see
similar cross in Table 10, ped. 1461 b).
Hondo Strains — Hp-1, Hp-2: Both strains
were descended from fish collected in the Rio
Hondo in 1954. Hp-1, which has been inbred
brother-to-sister for the last 15 generations, pos-
sesses the WY-YY sex-determining system. The
W chromosome carries no macromelanophore
gene; one of the Y chromosomes is marked by
the gene Sd and can be traced back to the off-
spring of Hp-1. The Y chromosome carrying
the wild type allele has been derived from Hp-1 1
(see also Table 8 for the early history of this
strain). Nine generations of this strain were ob-
tained by mating wild type females with Sd
males. These matings resulted in four classes of
offspring in approximately equal numbers:
Parents
w+ Y+ x T+ YSd
Offspring1
Females: 111 W+ YSd, 115 W+Y+\
Males: 118Y + YSd, 88 Y+ Y +
1 One additional Sd fish possessed no gonad.
Table 2. Inheritance of Pigment Genes and Sex Ratio in the New River (Np) Strain
of Xiphophorus maculatus
Parents
Offspring
Type
Female
of Cross
Male
Females
Males
N
N
N
Sr
Sr
Sd
N
Sr
+ i
Sd
Sr
Sd
SD
Sd1
+ i
w+ Yn X YSi Yar
39
30
1
1
3
46
39
-
4
5
l
1
W + YSd X Yn YSr
37
-
56
-
3
43
-
46
12
-
20
1
+ YSr x Ygd Yn
-
36
32
-
2
-
24
34
-
-
-
-
76
66
89
1
8
89
63
80
16
5
21
2
Total
240
276
1 Most of the wild-type males and females, as well as the Sd, Sr and N males, are due to nonpenetrance of the macro-
melanophore genes.
156
Zoologica: New York Zoological Society
[50: 13
Three other generations were obtained by
mating a Sd female with a wild type male.
Parents
1P+ YSd X Y + Y+
Offspring
Females: 64 W + Y+; Males: 61 Y + Y Sd
The sex ratio was 290 females to 267 males.
Strain Hp-2, which has been inbred brother-
to-sister for more than 18 generations, possesses
the XX-XY sex-determining mechanism. The Y
chromosome is marked by the Sd gene. Among
614 fish raised, only two exceptional males oc-
curred, but they were not testcrossed.
Parents
* + *+ X *+ YSd
Offspring
Females: 305 X + X + ;
Males: 307 A+ YSd, 2 X+ ?
Grijalva Strain — Gp: These platyfish, which
have been inbred for the last 13 generations,
possess the XX-XY sex-determining system.
The X chromosomes carry either the genes Sd
or Sp, and the Y chromosome is marked by Sd.
The sex ratio of 373 females to 350 males (in-
cluding all exceptions and individuals only par-
tially differentiated ) does not differ significantly
from unity. The high incidence of only partially
differentiated males may be related to pituitary
abnormalities that have recently been discovered
in this strain (Schreibman & Charipper, 1962).
The Gp strain can be traced back to a female
(XX) heterozygous for the Sp gene and to a
male (XSd Y+). In the third inbred generation
(ped. 864), an exceptional Sp Sd male oc-
curred which, when mated to one of his XSd XSd
sisters, sired offspring consisting of many Sp Sd
females and Sd males and 3 exceptional Sd
females (ped. 942, Table 3). From this series
of crosses it is apparent that the exceptional male
had the XSp Y Sd constitution and had arisen as
the result of a crossover.
One of the exceptional Sd females of pedi-
gree 942 was testcrossed to a X + Y Sr male (a
hybrid between a FIp-2 $ and a Np $ ).
Female 942 Male
Xad Y sd X X+ Y Sr
Fj (pedigree 1010)
Females: 8 Sd\ Males: 53 Sd Sr, 15 Sd
Although the frequencies of the three classes
of offspring differed significantly from expecta-
tion, the unusual sex ratio and the inheritance
of the Sr gene by the males only indicates that
the exceptional female had the XY genotype.
The exceptional Sd male of pedigree 718 was
also tested. When mated to a Jp 30 female
(XSl.XSr), 20 Sr females and 18 Sd Sr males
were produced. The exceptional male must have
resulted from a crossover.
Coatzacoalcos Strain — Cp : These fish pos-
sess the XX-XY sex-determining mechanism.
They have been bred by four types of brother-
to-sister matings for the last 17 generations.
Table 3. Inheritance of Pigment Pattern and Sex Ratio in the Grijalva (Gp) Strain
of Xiphophorus maculatus
Parents
Offspring
Ped.
No.
Female
Male
Females
Males
Sd
Sd
Sd
Sp
Sp
+
Sd
Sp
Sp
+
718
30
1
26
1
1
17
1
30
779
* + *S(2
—
16
12
-
16
-
-
14
864
x8PxSd
X8iY+
14
-
7
-
15
15
1
-
942
X Sd X sd
XSP Ysd
3
-
27
-
23
-
-
—
c m
r a
xSpxSd
X Sd Ysd
58
-
71
-
611
-
531
-
o n
s y
s
Xsd XSd
X sP Ysd
-
-
842
—
873
—
—
—
e
s
xSpxSd
XsP YSd
-
13
10
-
121
-
4
-
Total Number — Females: 373; — Males: 350; — No Gonads: 1
1 Fourteen of these '126 males possessed a modified anal fin that was arrested in its development, although the fish were five
to six months old.
- Several females had undeveloped gonads when sacrificed.
3 One additional fish had a well differentiated gonopodium, but no testis could be found upon autopsy.
1965]
Kallman: Genetics and Geography of Sex Determination in Xiphophorus maculatus
157
Table 4. Inheritance of Pigment Pattern and Sex Ratio in the Coatzacoalcos (Cp)
Strain of Xiphophorus maculatus 1
Parents
Offspring
Female
Male
Females
Males
No Gonad
Sd
Sp
+
Sp
Sd
+
Sp
XSp XSp
X + YSd
15
-
17
-
-
—
x3px+
X+ YSd
73
772
84
80
1
—
XSPX+
*SP Ysa
16
-
12
8
—
—
xsp YSd
20
—
—
21
—
63
Total: 201 2 ; 223 <J ; 6 no gonad.
1 For 12 out of 17 generations.
2 Many females isolated in an aquarium died and were not recorded.
3 These fish occurred among the offspring of a single female.
Complete records are available for twelve gen-
erations (Table 4). The excess of males is due
to the accidental loss of an aquarium of fe-
males, the number of which has not been re-
corded. The six Sp fish with no gonad occurred
among the offspring of a single female. The
single exceptional wild type male was not test-
crossed.
Jamapa Strains — Jp 30, Jp 163 A, Jp 163 B:
The origin of strains 30 and 163 has been de-
scribed by Gordon (1947) who showed that
Jamapa fish possess the XX-XY sex-determining
mechanism. Strain 30 is now in its 42nd gen-
eration of inbreeding. Both its X and Y chro-
mosomes are marked by gene Sr. The sex ratio
has not always been recorded, but complete
data are available for the 35th and the 38th
to 42nd generations inclusive (Table 5).
During the first six generations of inbreed-
ing, the X chromosomes of strain 163 were
marked either by gene Sd or Sp. Subsequently,
strain 163 was split into two sublines, A and B.
In the A line, which is now in its 30th genera-
tion of inbreeding, the Sd gene is located on the
Table 5. Sex Ratio in Jamapa (Jp) Strains of Xiphophorus maculatus
Parents
Offspring
Female
Male
Females
Males
Sd
Sp
Sd
Sp
Sd
Sp
Sr
Sr
Sr
Sd Sp
Sr Sr
Sr
Strain Jp 30
X Sr X8r
*8r Y Sr
-
-
137
-
-
- -
141
-
Strain Jp 163 B
XSp xsP
*sp YSr
—
387
—
—
9
— —
— —
386
Strain Jp 163 v
4
X3d XSd
xsd YSr
369
-
-
31
-
2
310
-
Distribution of Exceptional XY Females in Strain Jp 163 A
Generation
Mating
Offspring
XSd XSd ?
XSd Y gr 2
XSd Y Sr 8
14
a
5
8
2
17
a
18
1
10
17
b
17
5
16
24
a, b
27
14
16
24
c
1
1
2
28
a, b, d
44
0
17
28
c
41
1
21
31
a
15
1
12
31
b
17
0
10
158
Zoologica: New York Zoological Society
[50: 13
A chromosome, while in the B line, which has
been inbred for 26 generations, the X chromo-
some is marked by Sp. In both strains, the Y
chromosome is marked by gene Sr. In the past
the sex ratio of both strains has only been re-
corded every second or third generation unless
“exceptional” fish occurred. Therefore, the per-
centage of exceptions in both strains is actually
much lower than appears from Table 5. Both
strains are characterized by the sporadic occur-
rence of XY females (MacIntyre, 1961). In
strain 163 B, all nine exceptional females were
found among the offspring of a single fish of
the 11th generation. The 31 exceptional fe-
males in strain 163 A were produced by eight
females, four of which accounted for 27 of the
exceptions (Table 5). The two exceptional Sd
males of strain 163 A resulted from crossovers
between the X and Y chromosomes. When these
males were mated to females of strain 163 B,
50 of the offspring were Sp Sd females and 55
Sp Sd males (ped. 1297, 1700). The exceptional
males must have been homozygous for the Sd
gene.
B. The Sex Chromosome Mechanism of
Wild Populations of Xiphophorus macu-
latus
Belize River
In 1950 Gordon briefly mentioned that
platyfish collected in the Belize River possessed
the WY-YY sex-determining mechanism. How-
ever, no detailed experiments were ever pub-
lished. The crosses on which Gordon based his
conclusion are therefore listed here (Table 6) .
Two wild-caught males were mated with
Jamapa (AA) females. From these crosses 304
offspring were obtained, all males.2 This is con-
clusive evidence that the males had the YY
constitution.
Two wild-caught females (Bp-1, Bp-7) and
the daughters of two others (Bp 32, Bp 92) were
mated with their own Belize males or with
known XY males. The paternal pigment pat-
terns were inherited by one half of the male
and female offspring (ped. Bp-12, 309, 308)
while the pigment pattern of the female parent
was inherited only by the sons (ped. Bp-12, 329) .
This type of inheritance is diagnostic for the
WY-YY system. However, these crosses do not
rule out the possibility that one of the progeni-
tors may also have possessed an A chromosome.
New River
All knowledge about the sex-determining
2 Gordon (1951a) listed the offspring of one of these
crosses as 239 males and one female. But in the files
of the Genetics Laboratory the entry under this pedigree
lists only 239 males.
o
-c
a.
o
•c
ft.
es
s
m
o
a
s
o
ft
ft
o
Z
-d
o>
ft
+ | rr | | vo
v. 73 ^
^ CO
< Co
Z 1
1 1 ^ 1 1
73 1 2 <" "fr
lO 7 T-l
ft I ^
O3 04
ft ^ I I
^ m 1 1
I I I
+ I I N
Z I
<L> <U
ft a a
03 O O
a a
*2 I I
"a
to
112 1
£-111112:
to+-t-2oS +
ft ft ft ft ft ft
+ + fe; te; §
ft ft ft ft ft ft
Cl, CL CL Oh r\ . O
PC P5 CP PC 1— T cn
. -o 'W 33 -o I
&
ft ft ft ft ft ft
i- a + 4- j- +
ft ft ^ ^ ^ ^
^ m On
Q* Cl, Cl, Oh
<pq pq pp pp
Tf ' ON ON OO
O O 0-0 04 o
rh rh Cm rh (6 rh
Nonpenetrance of Jamapa Sd in inter-river hybrids.
1965]
Kallman: Genetics and Geography of Sex Determination in Xiphophorus maculatus
159
Table 7. Sex Ratio and Inheritance of Pigment Pattern Among the Descendants
of Wild-caught Xiphophorus maculatus from the New River
Parents
Offspring
Ped.
No.
Female
Male
Females
Males
Sd Sd
557
Cp
v+
Np-1 1
Sd
N
none
+
Sr
Sd
Sp
19
N
N
Sr
+
18
529
Jp
XapXs*
Np-1 2
Y+ y +
-
none
-
—
—
72
-
-
-
751
5302
Np-1
W+ YSr
unknown
9
i
13
6
3
—
2
—
7
6
5633
530-1
w+ rSd
530-13
YSrYN
—
24
19
—
24
—
—
16
—
—
5643
530-3
w+yn
530-11
Y Sr Ysd
5
—
6
—
—
—
8
4
-
-
6493
563-1
W+ Yn
530-14
Ysd YSr
16
—
22
—
1
—
19
8
-
-
1 Nonpenetrance of Jamapa Sd in inter-river hybrids.
2 Some fish were sacrificed before pigment patterns developed fully.
3 Fish not scored for Sr pattern.
mechanism of the platyfish population of the
New River has been derived from a single fe-
male and two males (Table 7). Both males
possessed the YY constitution, since crossing
them to Jamapa or Coatzacoalcos XX females
resulted in all-male broods. The female that
appeared to have been fertilized by several males
in nature, had the WY constitution. When one
of her Sd daughters was mated with one of her
N sons, one half of the male and female off-
spring inherited the N gene, while Sd was
inherited only by males. The same type of in-
heritance was observed when a female ( N ) was
mated to a male (Sd Sr). Inbreeding this pedi-
gree (649) gave rise to the Np strain. The
exceptional Sd male of pedigree 649 was not
testcrossed. It could have been a WY male (sex
reversal), a crossover between the W and Y
chromosome, or the result of nonexpressivity
of the N gene.
Rio Hondo Drainage
Three collections from this river system were
available for analysis. Two were made in the
Rio Hondo at San Antonio (1954) and Doug-
las ( 1963) and one in an isolated aguada in the
extreme headwater region at Tikal (1963).
Rio Hondo ( San Antonio, 1954): The crosses
pertaining to this collection have been summar-
ized in Table 8. Male Hp-1 1, when crossed with
a Jamapa XX female, gave rise to offspring of
both sexes (ped. 520), indicating that he pos-
sessed the XY constitution. Hp-1 was a WY
female; when one of her Sd sons was mated to
Hp-10, all-male broods were produced (ped.
552). This cross also demonstrates that female
Hp-10 was XX. Hp-2 must have been a WY
female. When one of her sons was testcrossed
with a Jamapa XX female, he sired all-male
offspring (ped. 558). Female Hp-3 gave rise to
Table 8. Sex Ratio and Inheritance of Pigment Pattern Among the Descendants
of Wild-caught Xiphophorus maculatus from the Rio Hondo (San Antonio, 1954)
Parents
Offspring
Ped.
No.
Female
Male
Females
Males
Sr
Sp
Sd
+
Sd
Sr
Sd
Sp
520
JP
Xgp XSd
Hp-1 1
5
2
-
—
—
—
4
527a
Hp-1
W+ Y+
unknown
—
1
2
4
—
—
3
552
Hp-10
X+X+
527a- 11
r+
—
none
—
30
—
—
—
537
Hp-2
W+ Y +
unknown
—
—
1
2
—
—
—
558
Jp
X Sr* Sr
537-11
Y Sd
—
none
—
—
25
34
—
Hp-32
Hp-3
X+X+
unknown
—
—
6
19
—
—
—
697
Hp-32
X+X +
Hp-32
YSd
—
—
19
21
—
-
—
551
Hp-5
YSd
Hp-11
Y +
—
-
29
15
—
—
—
650
551-1
w+ ?
551-11
YSd
—
7
7
9
—
—
—
736
650-3
W+ Y +
552-11
YSd
-
16
10
16
-
-
-
+
7
12
3
6
18
160
Zoologica: New York Zoological Society
[50: 13
a high percentage of males (ped. Hp-32), sug-
gesting that she was a XX female that had been
inseminated by both XY and YY males. A mat-
ing of one of her daughters with a son ( Sd )
produced only wild type females and Sd males
(ped. 697). This father-to-son inheritance is
diagnostic for the XX-XY type of sex-determi-
nation. Inbreeding pedigree 697 resulted in the
Hp-2 strain of X. maculatus. Female Hp-5,
which had been kept isolated from males for
eight months, was finally mated to Hp-1 1 (XY,
see ped. 520). Since this cross produced only
wild type females and Sd males, Hp-5 must
have been a WY female, with the Sd gene on the
Y chromosome. Hp-5 is a progenitor of the
Hp-1 line; its W chromosome can be traced back
to this female. Her offspring (ped. 551) were
inbred (ped. 650). A wild type WY female of
this brood was mated with an X + YSd male of
pedigree 552. Inbreeding of their offspring
(ped. 736) resulted in the Hp-1 line. The X
chromosome was eliminated three generations
later when a WY female was mated to a YSd Y +
male.
Rio Hondo ( Douglas , 1963): Four wild-
caught males from Douglas (ped. 1335) were
testcrossed with XX females belonging to the
Jamapa and Grijalva reference stocks. One
male gave rise to males and females in approxi-
mately equal numbers, indicating that he pos-
sessed the XY genotype. The other three males
must have been YY fish, since in all the crosses
only male offspring were produced (Table 9).
Eight females from the Douglas location (ped.
1335) possessed the WY chromosome consti-
tution. A ninth female was apparently an excep-
tional WW fish (Table 10). Seven sons of five
of the WY females were testcrossed with XX
females of the Jamapa and Coatzacoalcos stocks;
they gave rise to 338 offspring, all males (ped.
1506, 1482 a, 1461a, 1486, 1480, 1479,
1475). But when two of the males were mated
to known WY females of the New River refer-
ence stock, the offspring consisted of both sexes
in about equal frequencies (ped. 1482 b,
1461 b). Further evidence that these wild-
caught Douglas females were WY was provided
by crossing seven of their daughters with XY
males of the Jamapa and Grijalva strains. One-
half of the female offspring exhibited the
T-linked pigment pattern of the male parent,
and one-half of the male offspring inherited the
pigment gene located on the X chromosome of
the father. The female parents must, therefore,
have possessed the WY genotype (ped. 1459,
1467, 1508 a and b, 1540,^1557, 1460). In addi-
tion, the pigment pattern of four wild-caught fe-
males (1335-1, -2, -3, -4) was inherited only
by their sons, again strong evidence for the WY
genotype. Two females, 1335-7 and -9, were
shown to be WY by testcrossing them directly
with XY Jamapa males (ped. 1429, 1520).
Similarly, female 1335-8 was WY. Although
she produced only three young, her WY geno-
type was established by testcrossing each of
them. One daughter possessed the WY geno-
type, the other was a WX female, and the only
son was a XY male (ped. 1566, 1588, 1555).
Female 1335-6 appears to have been WW.
When she was mated to a XSp Y Sl. Jamapa male,
the offspring consisted of equal numbers of Sp
and Sr females, but no males (ped. 1422).
Although only 29 fish were reared, it is unrea-
sonable to attribute the absence of males to a
recessive lethal gene. Even if such a gene had
existed on the “Y” chromosome of the female
parent and also on the Y chromosome of the
Jamapa strain, at least one type of male (the
XY class) should have been found among the
offspring. It is also possible that 1335-6 had the
WX genotype, however, since the X chromo-
some is present in the Rio Hondo platyfish popu-
Table 9. Sex Ratio and Inheritance of Pigment Pattern Among the Offspring of Four
Wild-caught Male Xiphophorus maculatus from the Rio Hondo (Douglas, 1963)
Parents
Offspring
Female
Male
Reference
Wild-
Females
Males
Ped. No.
Strain
caught
Sp
Sd
Sp
Sd
+
1356a
JP
XSp
1335-11
27
—
27
-
-
1356b
Gp
% Sd XSp
1335-11
Y+ Y +
9
15
10
4
-
1371a
JP
*SP *sp
1335-14
Y Y
1 + 1 +
none
40
—
—
1371b
Gp
Xsa^sp
1335-14
Y Y
+ +
none
19
19
-
1385
Jp
XSpXSp
1335-15
Y Y
1 + 1 +
none
66
-
-
1387a
JP
XSp XSp
1335-16
Y Y
+ 1 +
none
28
—
—
1387b
Gp
Xsa^sp
1335-16
Y Y
1 + 1 +
none
6
8
-
1965]
Kallman: Genetics and Geography of Sex Determination in Xiphophorus maculatus
161
lation. In this case the sex ratio would have been
2 Sp $ : 1 Sr 2 : 1 Sr $ . Again, the proba-
bility that no males would occur among 29 off-
spring is extremely small. Moreover, the
observed ratio of Sp and Sr females is not in
accordance with the expectation (%2 = 14;
n = 2; p < .01). On the other hand, if the
Douglas female had the WW genotype, the off-
spring should consist of equal numbers of Sp
and Sr females and no males, and the actual
result fits this theoretical expectation very well.
The WW female probably arose from a mating
between a WY female and an exceptional WY
male. Such males have been reported to occur
sporadically in laboratory stocks ( Bellamy &
Queal, 1951; Breider, 1942; Gordon, 1951a;
Oktay, 1959 a, b) and are also to be expected
in nature. A male offspring of a wild-caught
female from another location of the Rio Hondo
drainage possessed the WY genotype (Table 12,
ped. 1363 b).
Other exceptional fish were observed among
the descendants of the Douglas platyfish. One
of the wild type males of pedigree 1461 b must
have had the WY genotype, since males and
females were produced when it was mated to a
XX female (ped. 1668). When mated to a
W+ Y Sd female of the Hp-1 reference stock,
the same male sired a brood that consisted of
90% females, half of them exhibiting the Sd
pattern of the female parent (ped. 1636). These
results are in agreement with the assumption
that the male had the WY genotype. The other
exceptional male of pedigree 1461 b was not
tested. The wild type and Sd males of pedigree
1482 b resulted from nonexpression of the N
gene (ped. 1689, 1737).
The two exceptional Sd males and females of
pedigree 1555 presumably had the Sp Sd geno-
type. In this pedigree the Sp pattern was some-
times weakly developed while the Sd gene was
strongly expressed, often accompanied by a
“spillover” from the dorsal fin onto the flanks.
Therefore, the Sp is sometimes masked by the
Sd. The exceptional females died before being
testcrossed. They could have been either WY
females (the result of a crossover) or XY fe-
males (sex reversal).
Aguada Corriental ( Tikal ): Six wild-caught
males (ped. 1343) from this small pool were
tested directly with XX females of three refer-
ence stocks (Gp, Jp 163 A and B), four of
them with two females each. Since the crosses
resulted in 374 offspring, all of them males
(Table 11), the wild-caught fish must have pos-
sessed the YY chromosome constitution.
Evidence from three types of matings shows
that all Tikal females (ped. 1343) were of the
WY genotype (Table 12). A total of 449 young
were obtained, all males, when eleven of the
sons of wild-caught fish were mated with XX
Jamapa females, (ped. 1529, 1440, 1495, 1556,
1523, 1533, 1505, 1660, 1565, 1625, 1441).
When two of the sons were mated to the daugh-
ters of wild-caught Tikal females, males and
females were produced in a 1 : 1 ratio (ped. 1468,
1435). In addition, some of the daughters of
wild-caught females were mated to XY males of
reference strains. In each cross, one-half of the
female offspring inherited the pigment gene lo-
cated on the Y chromosome of the male parent
(ped. 1438, 1442, 1538 a and b, 1539, 1534 a
and b, 1535, 1547). The results of all of these
crosses could only be consistent with the assump-
tion that Tikal females possess the WY genotype.
The Tikal matings gave rise to a single excep-
tion — the wild type male found among the off-
spring of female 1343-4 (ped. 1363 b). All the
sons should have exhibited the Nigra gene which
she carried on the Y chromosome. In order to
determine whether the exceptional male was
WY or a YY male that arose from a crossover
between the W and Y chromosome, it was mated
to a Jamapa (XX) female. The mating resulted
in males and females in approximately equal
numbers (ped. 1531), and this is strong evi-
dence that the genotype of the exceptional fish
was WY. That the females of pedigree 1531
had indeed inherited a W chromosome from
their father was demonstrated by crossing one
with a Jamapa (XY) male (ped. 1609). This
cross resulted in a sex ratio of 3 females to one
male, and about one-third of the females ex-
hibited the y-linked Sr trait of the Jamapa male.
Lake Peten
Two platyfish collections were made in Lake
Peten, one near Flores at the western end (1954)
and the other near Remate at the lake’s eastern-
most tip ( 1963).
Lake Peten (1954): The crosses pertaining
to this collection have been summarized in
Table 13. Three males, when mated to XX
females, produced both male and female off-
spring and must have possessed the XY geno-
type (ped. 532, 550, 549). A fourth male was
apparently YY (ped. 545). The sex chromo-
some constitution of only a single wild-caught
female, Pp-1, was identified. The analysis is
quite complicated, since only one macromela-
nophore pattern. Spotted-dorsal (Sd), was
present among her offspring and this showed
great variation in expressivity, and in several
cases no penetrance at all. Pedigrees 626, 640,
574 and 602 indicate that Pp-1 possessed a W
chromosome. Two male descendants, 574-13
Table 10. Sex Ratio and Inheritance of Pigment Pattern Among the Offspring of Nine Wild-caught Female Xiphophorus maculatus
from the Rio Hondo (Douglas, 1963)
162
Zoologica: New York Zoological Society
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Table 10. Sex Ratio and Inheritance of Pigment Pattern Among the Offspring of Nine Wild-caught Female Xiphophorus maculatus
from the Rio Hondo (Douglas, 1963) ( Continued )
Parents Offspring
1965]
Kallman: Genetics and Geography of Sex Determination in Xiphophorus maculatus
163
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and 602-11, sired all-male broods and must
have had the YY constitution (ped. 698 and
781). Consequently, two daughters of Pp-1
(533-3 and -5) were WY females. Unless one
assumes that the wild type phenotype of the 15
males of pedigree 595 resulted from nonpene-
trance of the Sd gene, there is good evidence
that a third daughter (533-8) was XX. The sex
ratio of pedigree 654 also shows that one son,
533-19, was XY. All crosses indicate that Pp-1
was a WX female and was fertilized by at least
two males, one XY the other YY. The son of
a second Peten female, Pp-2, appears to have
been XY (ped. 595).
Lake Peten (1963): The crosses involving
this platyfish collection (ped. 1341) also indi-
cate that both W and X chromosomes are pres-
ent. Seven wild-caught males were tested with
XX females of the Jamapa and Grijalva refer-
ence stocks (Table 14); four were found to
possess the XY genotype (ped. 1396 a and b,
1437, 1408, 1413) and three the YY genotype
(ped. 1388 a and b, 1416, 1439).
Among the offspring of one Peten male
(1341-16), six exceptional fish occurred (ped.
1413). The other males of this pedigree exhib-
ited the expected Sp Sd phenotype. Since the Sd
pattern was strongly developed, it seemed un-
likely that the Sp males had resulted from non-
penetrance of the Sd gene. When two of these
exceptional males were testcrossed with XX-
Jamapa females, all-female broods resulted
(ped. 1580, 1595), clearly indicating that they
were XX. The cause of the high incidence of
sex-reversed males (XT) is not apparent.
Of seven wild-caught Peten females tested
(Table 15), one possessed the WX, another the
XX and four the WY genotype. For one female
our analysis is incomplete; only a W chromo-
some was identified. Female 1341-1 exhibited
the Nigra pattern and must have possessed the
WX genotype. One of her wild type daughters
was WY; when she was mated with a XSp YSr
Jamapa male, the Sp and Sr patterns were in-
herited by both sexes (ped. 1522). Her Nigra
daughter, however, was XX; when she was
mated to a Jamapa male, the Sr gene was in-
herited by the male offspring only (ped. 1562).
The sons of female 1341-1 were XY males
(ped. 1485, 1490).
Among the descendants of this Peten female
an unusually large number of males and fe-
males appeared that exhibited the pigment pat-
tern of the opposite sex. In pedigree 1562, all
males should have been Sr, but one exhibited
only the N pattern. It was mated to a Jamapa
(XX) female. Among 57 offspring, ten were
males (ped. 1685). Because of the small per-
164
Zoologica: New York Zoological Society
[50: 13
Table 11. Sex Ratio and Inheritance of Pigment Pattern Among the Offspring of Six
Wild-caught Male Xiphophorus maculatus from the Aguada Corriental (Tikal)
Parents
Offspring
Ped. No.
Female
Male
Females
Males
(Reference Strain)
(Wild-caught)
Sr
Sr
Sp
Sd
Sp
Sd
+
1364a
Jp
X Sp
1343-13
y + y +
none
60
—
— ■
—
—
1364b
Gp
xSaxSa
1343-13
Y+ Y +
none
—
54
—
—
—
1367a
JP
*SpxSp
1343-14
y + y +
none
30
—
—
—
—
1367b
Gp
xsaxSd
1343-14
Y Y
none
—
34
—
— -
—
1393a
Jp
xSp*Sp
1343-15
Y Y
1 + 1 +
none
35
—
—
—
—
1393b
Gp
XSp XSd
1343-15
y+y +
none
13
14
—
—
—
1407a
Jp
XSPXSP
1343-16
ySry +
none
19
—
19
—
—
1407b
Gp
1343-16
Yar Y_|_
none
10
8
7
5
—
1414
Jp
xaaxaa
1343-17
Y Y
1 + 1 +
none
—
—
—
—
391
1427
Jp
XSd XSd
1343-18
Y Y
1 + 1 +
none
—
—
—
—
271
Total Number: 374
1 Nonpenetrance of Jamapa Sd in inter-river hybrids.
centage of male offspring (18%) and the in-
heritance of the Nigra pattern by both sexes, it
is concluded that the exceptional male of pedi-
gree 1562 had the XX genotype. If this is so,
then the ten males of ped. 1685 should also have
had two X chromosomes, but none of these was
ever testcrossed.
In pedigree 1485, all females should have
exhibited the Nigra and males the Spot-sided
pattern. However, one exceptional Sp female
was discovered. In a mating with a Jamapa male,
she behaved like a typical XX female (ped.
1649). This female, therefore, arose as a result
of crossing over between the X and Y chromo-
somes. Among her 143 offspring, four excep-
tional fish, two males and two females, were
detected. In view of the rarity of crossing over
between the X and Y chromosomes in Jamapa
strains (Tables 5, 24), the two females presum-
ably had the XY and the males the XX genotype.
In pedigree 1490, a cross very similar to the
one just described, the Nigra pattern should
have been inherited only by the females, but a
single N male occurred. This male did not arise
as a result of crossing over; in a mating with a
Jamapa XX female he sired 71 females and
two males (ped. 1570). The Nigra male and its
two male offspring therefore possessed the XX
constitution. Both males of pedigree 1570 were
backcrossed once more to the Jamapa strain.
One male gave rise to 53 offspring, all females,
the other to 71 females and ten males (ped.
1686, 1687).
The genotype of female 1341-2 was identified
as XX. One of her Nigra and two of her wild
type sons proved to be XY males (ped. 1550,
1576, 1590). One of her wild type daughters,
when mated to an unrelated Peten male, was
shown to be a XX female (ped. 1498 a; listed
among the offspring of 1341-4).
Peten females 1341-3 and -4 had the WY
chromosome constitution; some of their sons
when mated to XX Jamapa females sired all
male broods (ped. 1574, 1579). Other sons
proved to be XY males (ped. 1504, 1498 a and
b, 1496 b). Some of the daughters of the Peten
females possessed the WY, others the WX con-
stitutions. Both classes of females were mated
with XY males, the X and Y chromosomes
marked by different pigment genes. The WX
genotype of some daughters was demonstrated
by a 3 : 1 sex ratio and the fact that the female
offspring consisted of three pigment classes and
the males of only one (ped. 1575 a and b, 1513 a
and b). The WY genotype was identified by a
1 : 1 sex ratio and the inheritance of the Y-linked
pigment pattern of the father by both sexes
(ped. 1524, 1496 a). The results also indicate
that both wild-caught Peten females had been
fertilized by XY males.
Among the descendants of these females, six
fish exhibited the pigment patterns of the oppo-
site sex (two females of pedigree 1504, one
female of pedigree 1657, one female and one
male of pedigree 1498 a, one male of pedigree
1496 b). Four proved to be crossovers (ped.
1657, 1656, 1618, 1670). The high percentage
of crossing over in these sibships is quite un-
1965]
Kallman: Genetics and Geography of Sex Determination in Xiphophorus maculatus
165
usual, in view of the low incidence of crossing
over in other crosses. In pedigree 1498 a, among
62 fish, there were at least two crossovers. The
exceptional Sr female of pedigree 1657 was a
XY female (ped. 1724). One wild type female
of pedigree 1504 was not tested.
Peten females 1341-8 and -9 were kept iso-
lated in the laboratory for six months (no
broods produced) and then mated with Jamapa
males. From the inheritance of the pigment pat-
terns among the offspring, it is obvious that they
were both WY females (ped. 1447, 1451). The
analysis of the sex chromosome constitution of
Peten female 1341-5 is incomplete. Her two
sons died before they could be tested. Since three
of her daughters possessed the WY genotype
(ped. 1516, 1559 a and b), this wild-caught
Peten female must have possessed a W chromo-
some.
Rio Usumacinta System
Three collections of platyfish were made in
the Rio Usumacinta system, two near the origin
of the Rio de la Pasion at Sebol and one in the
headwaters of the Rio San Pedro.
Rio de la Pasion: The two collections of
platyfish from the Rio de la Pasion were given
pedigree No. 1327 and 1328. These fish or their
descendants will also be referred to as the
“Sebol” platyfish.
Five wild-caught males were tested directly
by mating them with one or two XX females of
the Jp, Gp and Hp-2 reference stocks (Table
16). Since the sex ratio of the offspring was of
primary importance, some were sacrificed before
their pigment pattern had developed. The five
males were found to possess the XY constitu-
tion. The sex ratio of only one cross (ped.
1362 a) differed significantly from the expected
1:1 ratio (y? = 8.9, p < .01). In order to de-
termine whether the paucity of males was some-
how related to the Y chromosome of male
1327-14, one of his sons (ped. 1362 a) was
crossed with a Jamapa XX female. This cross
resulted in 50 females and 56 males, a good 1 : 1
ratio. Similarly, when male 1327-14 was mated
to a second XX female belonging to the Grijalva
strain, a normal sex ratio was obtained (ped.
1362 b). The exceptional Sp Sd male of pedi-
gree 1347 b was not testcrossed.
Six Sebol females were tested; four exhibited
the WY and one the XX genotype. One female,
for which the analysis is incomplete, possessed
at least one X chromosome (Table 17).
A male offspring of this Sebol female (1327-1)
was XY (ped. 1476). One daughter was XX,
since only male offspring were obtained when
she was mated to a YY Sebol male (ped. 1419).
Since no other daughters of female 1327-1 were
tested, it cannot be decided whether she was
WX or XX. All evidence indicates that female
1328-2 possessed two X chromosomes. The sex
ratio and the pigment patterns of her offspring
(ped. 1336) strongly suggest that she was fer-
tilized by two XY males, one XSr, and the other
wild type. Four of her daughters, three Sd and
one wild type, were tested in three different
ways; all proved to be XX (ped. 1424, 1507 a
and b, 1510). The single son tested proved to be
XY (ped. 1466).
The sex chromosome constitution of Sebol
females 1327-3, 1328-1, -3 and -4 was identi-
fied as WY, since each of them gave rise to
sons that produced all-male offspring when
mated to XX females of the reference strains
or from the Sebol location (ped. 1477, 1469 b,
1537, 1456 b, 1478 a) . But when the same males
were mated to their sisters or to other Sebol
females carrying a W chromosome, male and
female offspring were produced in nearly equal
numbers (ped. 1469 a, 1456 a, 1478 b). The
existence of a IT chromosome among the daugh-
ters of three of the wild-caught females was also
demonstrated by mating their daughters to XY
males (ped. 1420, 1421, 1517 a and b, 1525).
It was also shown that Sebol male 1327-12,
which was not tested with any of the reference
stocks, must have possessed the constitution
XSpY+ (ped. 1420). The 3: 1 sex ratio and the
fact that the pigment pattern of the male parent
was exhibited only by some females while all
sons were wild type, is in agreement with the
assumption that female 1352-1 was WX and
male 1327-12 was XSp Y + . Since the mother of
1352-1 was a WY female, she must have been
fertilized in nature by a XY male. The existence
of WX and XX fish among the female offspring
of pedigree 1420 was verified through addi-
tional crosses ( ped. 1511a and b, 1512) .
Similarly, male 1328-16 that fertilized female
1328-4 must have possessed the XY genotype,
since two of four daughters tested proved to be
WX females. When crossed with XY Jamapa
males, they gave rise to offspring with a 3:1
sex ratio, and the X chromosome of the male
was inherited only by the females (ped. 1517 b,
1525).
Among the progeny of the crosses listed in
Table 17, only a single exceptional fish was dis-
covered: the Sp female of pedigree 1421. This
fish was mated with an Jamapa male (AT)
homozygous for the Sr gene. Since the Sp gene
showed strictly maternal inheritance (ped.
1610), it is concluded that the exceptional fe-
male resulted from a crossover between the W
and Y chromosomes.
166
Zoologica: New York Zoological Society
[50: 13
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Table 12. Sex Ratio and Inheritance of Pigment Pattern Among the Offspring of Eight Wild-caught Female Xiphophorus maculatus
from the Aguada Corriental (Tikal) ( Continued )
Parents Offspring
1965]
Kallman: Genetics and Geography of Sex Determination in Xiphophorus maculatus
167
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Rio San Pedro: Thirteen platyfish (ped. 1342)
were collected at Carmelita after several hours
of seining. Five differentiated into males, seven
into females and one died. None exhibited any
macromelanophore pigment patterns. All the
crosses involving these fish and their descend-
ants have been summarized in Table 18.
One male, when mated to Jamapa and Gri-
jalva XX females, gave rise to male and female
offspring in approximately equal frequencies
and, therefore, must have had the XY genotype
(ped. 1395 a and b). Four males, when tested
with XX reference stocks, sired all-male broods,
indicating that they possessed two Y chromo-
somes (ped. 1399 a and b, 1455, 1445, 1472).
In contrast, when three of these YY males were
mated with five Carmelita females, both male
and female offspring were obtained (ped. 1405
a and b, 1412, 1425 a and b). The sex chromo-
somes of the five wild-caught females were
identified by mating a male Fj of each intra-
Carmelita cross with Jamapa XX females. Only
male offspring were obtained from all the
crosses (ped. 1521, 1514, 1518, 1528, 1526).
The F, males must have possessed the YY con-
stitution and the five wild-caught females must
have been WY. In two cases, the existence of a
W chromosome was also demonstrated by mat-
ing a female F, of an intra-Carmelita cross with
a Jamapa XSpY8r male (ped. 1465, 1449).
The sex chromosomes of the two other Car-
melita females, 1342-1 and -2, were also identi-
fied as WY by crossing them with Jamapa
XSp YSl. males (ped. 1380 a and b).
Rio Grijalva
Information on the sex chromosomes of the
Rio Grijalva platyfish population is based upon
two females and four males. Although certain
critical crosses were not performed, and in
several crosses few offspring were obtained, the
data demonstrate that both W and X chromo-
somes were present in these fish (Table 19).
Another difficulty in interpreting the Grijalva
data is that none of the fish were testcrossed
with the reference stocks during the first gen-
erations in the laboratory.
The offspring of female Gp-1, which was
gravid when collected, consisted of Sp and wild
type males and females (ped. 450). One female,
450-1, was mated to a X+ Y ai male and gave
rise to Sd males and females and wild type males
(ped. 512). The absence of wild type females
cannot be explained, but the appearance of Sd
offspring among both sexes strongly suggests
that the female parent possessed a W chromo-
some inherited from Gp-1. That 450-1 had the
WY constitution was demonstrated by the fact
168
Zoologica: New York Zoological Society
[50: 13
that one of her Scl sons was a YY male; when
mated to a XX female heterozygous for the Sp
gene, he sired only male offspring of the four
pigment phenotypes (ped. 605).
Other evidence indicates that female Gp-1
had the WX constitution. After having been
isolated from males for several months, she was
mated with Gp-1 2, a male known to be YY
(ped. 451 b), heterozygous for Sd (ped. 477).
This mating produced both Sd and wild type
males and females, a pattern of inheritance only
possible if the mother is WY or WX and the
father YY. One of the Sd males of pedigree All
was then mated with a female known to be XX
and, with a single exception, wild type females
and Sd males were obtained (ped. 511). Since
Gp-1 2 possessed two Y chromosomes, his male
offspring must have inherited the X chromo-
some from Gp-1. Further evidence that Gp-1
possessed an X chromosome was obtained
through additional crosses. Two Sp females of
pedigree 450 were mated with Grijalva males
Gp-14 and -15 (ped. 475, 476). Since the wild
type daughters of these crosses both proved to
be XX females (see ped. 511, 518), it follows
that the Sp females of pedigree 450 had the XX
constitution, and that Gp-1 must have possessed
one X chromosome. Moreover, at least one of
the males that fertilized Gp-1 in nature must
have possessed the XY constitution, and Gp-14
and Gp-15 must be XY males.
When female Gp-2 was mated first with
Gp-1 2 and then with Gp-1 3, exclusively male
offspring were produced. This indicated that
both males had the YY and Gp-2 the XX con-
stitution.
Rio Coatzacoalcos
Gordon (1951 a and b, 1954) briefly re-
ported that platyfish collected in the Rio Coatza-
coalcos had the XX-XY type of sex-determina-
tion, but he published only the results of two
crosses (ped. 270 and 274). The latter, which
arose from the mating of a WY female (strain
“Bh”, of unknown geographic origin) and Cp-18,
a Coatzacoalcos male, is especially noteworthy,
since the entire WY class differentiated into
functional males contrary to expectations. These
results have given rise to the theory that the Y
chromosome of these Coatzacoalcos fish is
stronger “male determining” than the Y chromo-
some of other populations. This pedigree and
others involving ten wild-caught Cp fish have
been listed in Table 20. The macromelanophore
pigment pattern of all four wild-caught females
was inherited by one-half of their male and fe-
male offspring, while the pigment pattern of six
wild-caught males was inherited either by all the
daughters or by all the sons. This type of in-
heritance is characteristic of the XX-XY mech-
anism.
Table 13. Sex Ratio and Inheritance of Pigment Pattern Among the Descendants of
Wild-caught Xiphophorus maculatus from Lake Peten (1954 collection)
Parents
Offspring
Ped.
No.
Female
Male
Females
Males
N
Sd
Sp
N
+
Sd
Sp
N
Sd
+
532
Jp
% Sp XSd
Pp-1 2
t+f+
—
33
—
231
—
49
—
—
541
550
Cp2
X+*N
Pp-1 3
*+
—
—
—
223
—
—
—
—
183
545
Cp-
Pp-1 4
— •
none
—
—
—
—
7
—
12
549
Cp
X+ Xsa
Pp-1 5
t+f+
5
—
—
6
14
—
—
—
8
548
Pp-2
?
Pp-1 1
*+ r+
—
—
—
3
—
—
—
—
9
5923
548-1
9
532
—
—
—
8
—
—
—
—
12
533
Pp-1
w+x+
?
XY, YY
11
—
—
21
7
—
—
—
20
626
533-1
w + ?
530-1 14
YSd YSr
9
—
—
13
13
—
—
—
8
640
533-9
564-1 l1
Yn YSd
5
—
3
19
15
—
—
11
2
574
533-3
w+ Y +
533-13
9 Y
1 Sd
4
—
—
6
8
—
—
—
7
602
533-5
W+ Y +
533-15
Y+
13
—
—
16
15
—
—
—
15
595
533-8
X+Xsd
548-13
*+ y+
2
—
—
15
7
—
—
—
15
698
595-3
X+X +
574-13
Y+ YSd
—
none
—
—
28
—
—
—
27
654
595-1
533-19
X+ Y +
4
—
—
26
3
—
—
—
16
781
654-9
602-11
Y+ YSd
—
none
—
—
13
—
—
—
18
1 Nonpenetrance of Jamapa Sd in inter-river hybrids.
2 The descendants of pedigree 300; see Table 20.
3 Fish not scored for pigment patterns.
4 Descendants of New River fish; for history of pedigree see Table 7; pedigree 626 not scored for Sr pattern.
1965]
Kallman: Genetics and Geography of Sex Determination in Xiphophorus maculatus
169
Table 14. Inheritance of Pigment Pattern and Sex Ratio Among the Descendants of Seven
Wild-caught Male Xiphophorus maculatus from Lake Peten (1963 collection)
Parents
Offspring
Ped.
No.
Female
Male
Females
Males
Sp Sp
1388a
Jp
xsP XSp
1341-12
y + Y +
Sp
Sd
N Sr
none
Sr
+
Sp
31
Sd
Sd
+
2i
1388b
Gp
XSp X8d
1341-12
y + Y +
— -
—
none
—
—
18
17
—
6i
1396a
Jp
x3dxSi
1341-13
X+ Y +
—
—
— — -
—
352
—
—
—
372
1396b
Gp
xSvxsa
1341-13
X+Y+
10
9
— —
—
8i
5
5
—
41
1437
Jp
XSd X sd
1341-14
xnY +
—
—
182 —
—
—
—
—
—
I72
1408
Gp
XSp X8d
1341-15
X+Y +
14
8
— —
—
4i
14
6
—
3i
1413
Jp
X8p XSp
1341-16
x+YSd
12
6
—
22
—
1580
Jp
XSr X8r
1413-11
X8PX +
—
—
— 34
19
—
—
none
—
1595
Jp
XSr X8r
1413-12
xsPx +
■ —
- —
— 33
29
—
—
none
—
1416
JP
xsdxsd
1341-17
Y Y
1 + 1 +
—
—
none
—
—
—
—
—
552
1439
JP
X8pX8p
1341-18
Y Y
1 + 1 +
—
—
none
—
—
50
—
—
—
1 Expressivity of pigment patterns is highly variable in all Peten hybrids. The wild type fish are undoubtedly due to non-
penetrance of the macromelanophore genes involved.
2 Nonpenetrance of Jamapa Sci in inter-river hybrids.
Discussion
Geography
These experiments provide convincing evi-
dence that platyfish, Xiphophorus maculatus ,
with the XX-XY and WY-YY sex-determining
mechanisms are not isolated from each other,
but occur side by side and interbreed over a
vast area (Table 21). By means of appropriate
crosses both W and X chromosomes have been
found in fishes from the Rio Grijalva at Villa-
hermosa, from the Rio Usumacinta system at
Sebol and Carmelita, from Lake Peten and from
two areas in the Rio Hondo (Table 21). The
distance by air from Villahermosa (Rio Gri-
jalva) southeastward to Sebol is 400 km., from
Villahermosa eastward to the mouth of the Rio
Hondo is 480 km., and from Carmelita south to
Sebol is 180 km. This area comprises about 60
per cent, of the total range of this species.
Populations in which only the WY-YY mech-
anism has been identified inhabit the New River
and Belize River in British Honduras. The area
in which the WY-YY system may exist exclu-
sively is therefore quite limited and could ex-
tend from the mouth of the New River south
for at least 210 km. to Mango Creek, the south-
ernmost location in British Honduras from
which platyfish have been taken. This is no
more than 10 per cent, of the range of
X. maculatus, since the coastal plain in British
Honduras is quite narrow, varying from a width
of 45 km. between the New River and the
Caribbean in the north to less than 30 km. be-
tween the Maya Mountains and the sea in the
south. Only the XX-XY mechanism is known
from the platyfish populations of the Rio
Jamapa, Rio Papaloapan and Rio Coatzacoalcos.
Between the Rio Grijalva and the Rio Jamapa,
a distance of 320 km., the coastal plain is no-
where more than 100 km. wide. This area con-
stitutes roughly 30 per cent, of the platyfish
range.
An experiment of this type is subject to a
large sampling error, since X. maculatus as well
as many other poeciliid fishes, although wide-
spread, often exist in small, local breeding popu-
lations with only limited gene flow between them
( Darnell, 1962; Gordon & Gordon, 1957; Has-
kins, Haskins, McLaughlin & Hewitt, 1961;
Kallman, 1964). Platyfishes tend to stay close
to banks, aggregate in favorable locations and
apparently do not disperse over any great dis-
tances. Fish from a given collecting station are
much more similar in genetic makeup to each
other than to fish taken a few hundred meters
or more away and may not be representative of
the population of an entire stream system. The
W or X chromosome or one type of male may
easily be excluded by chance from a small
sample. Since many crosses are often necessary
for the unequivocal identification of the sex
chromosomes of wild-caught females, only a
few fish from each collecting station can be
tested in the laboratory. The danger of acci-
dentally excluding fish of one genotype from
the analysis is thus quite serious. This difficulty
is well illustrated by the platyfish from Car-
melita: among the 12 fish analyzed, only one
170
Zoologica: New York Zoological Society
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Kallman: Genetics and Geography of Sex Determination in Xiphophorus maculatus
171
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X chromosome was found. In the sample from
the Rio Hondo ( 1963), one X chromosome was
present among 13 fish (Table 21). On the other
hand, in the 1954 collection from the Rio Hondo
the percentage of X chromosomes was much
higher. Among the Sebol platyfish, four out of
six females possessed the WY genotype yet all
seven males tested were XY .
Because few individuals were tested, one
cannot be certain that in the Belize and New
Rivers only the ITT-TT system occurs. It
would be surprising if eventually the X chromo-
some were not demonstrated in the Belize River,
since one of its headwaters, the Rio Mopan,
comes within three kilometers of tributaries to
the Rio Hondo and to streams running into Lake
Peten. No obvious physical boundaries separate
the stream systems from each other.
The evidence for the XX-XY system of the
Rio Jamapa populations is based upon experi-
ments involving 11 fish (Gordon, 1947), part
of a larger collection taken at the very mouth
of the river. The claim for the XX-XY mecha-
nism of the Rio Papaloapan population rests
upon a still smaller sample. The crosses reported
by Gordon (1947) do not involve wild-caught
fish but their descendants. All eight fishes listed
in his table may have been the offspring of a
single mating. This is certainly true for all Sb
(Spotted-belly) fish, since this gene can be
traced back to one Sb male (Gordon, 1946).
The analysis of the Coatzacoalcos population is
based upon ten fish. Nothing is known about the
sex-determining mechanism of the fish from the
Rio Tonala. Since numerous swamps and water-
courses connect this river with the Rio Grijalva,
both IT and X chromosomes would be expected
here, too.
Stability of Sex-Determining Mechanism
The sex-determining mechanism of X. macu-
latus is a stable one. A 1 : 1 sex ratio has been
observed in our laboratory stocks, some of
which have been inbred at least 30-42 genera-
tions. Similarly, Bellamy & Queal (1951) found
no significant deviation from a 1 : 1 ratio among
the offspring of several hundred crosses involv-
ing domesticated strains of platyfish. There are
four types of matings (WY $ X YY $,
WY 2 X XY $ , 1TX $ X YY $ and
XX $ X XY $ ) that nearly always give rise
to a 1:1 sex ratio, regardless of whether the
parents belong to the same or to different geo-
graphical populations (Table 22). A ratio of
three females to one male is obtained from
crosses between WX $ and AT $ (Table 22),
and YY males always sire all-male broods when
mated with XX females (Table 23).
172
Zoologica: New York Zoological Society
[50: 13
Table 16. Sex Ratio and Inheritance of Pigment Pattern Among the Offspring of Five
Wild-caught Male Xiphophorus maculatus from the Rio de la Pasion (Sebol)
Parents
Offspring
Female
Male
Females
Males
Ped. No.
(Reference Strain)
(Wild-caught)
Sd
Sd
Sd
Sp
Sp
+
Sd
Sp
Sp
+
1347a
Jp
xgpxBp
1328-12
X sd -^ +
—
35
—
—
32
—
—
1347b
Gp
XsP
1328-12
6
—
9
—
4
9
1
41
1345a
Jp
1328-11
X + TSp
—
—
382
—
442
—
—
1345b
Gp
xSp xSd
1328-11
x+Yb,
4
8
—
ll1
—
131
6
31
1359a
Jp
^Sp X gp
1327-13
X+ Y +
18
—
—
—
20
—
—
1359b
Gp
XSpXSa
1327-13
X+ Y +
10
12
—
—
17
14
—
—
1362a
JP
*SP *sP
1327-14
X+ Y +
39
—
—
—
16
—
—
1362b
Gp
XspXst
1327-14
X+ Y +
4
14
—
31
6
6
—
31
1493
Hp-2
x+x+
1328-14
*saY+
12
—
—
—
—
—
—
15
Total Number:
223
213
1 These fish were sacrificed at the age of three months before all pigment patterns were fully developed.
2 Nonpenetrance of Jamapa Sd in inter-river hybrids.
One exceptional situation has been found. In
18 of the 20 crosses between WY females of
the Rio Hondo (the Douglas and Tikal loca-
tions) and XY males, females outnumbered
males. The excess of females was statistically sig-
nificant in only one pedigree, but when the
offspring of all 20 crosses are grouped, the
deviation from 1 : 1 becomes highly significant
(Table 22). Crosses between Rio Hondo males
and females were not made in sufficient num-
bers to ascertain whether a high percentage of
females is characteristic for the population or
whether this occurs only in certain inter-
population matings. However, no deviation
from a 1 : 1 sex ratio has been observed in the
two inbred Rio Hondo strains. Differential mor-
tality after birth cannot explain the excess of
females, since the number of fish that died be-
fore sexual maturity is negligible. The prepon-
derance of females may result from a selective
mortality of males before birth (although this
cannot be the case in the other stocks or popu-
lations that exhibit a 1:1 sex ratio), from a
preferential fertilization of “W” eggs, or from
a not quite random segregation of chromosomes
during oogenesis so that slightly more W than Y
chromosomes are incorporated into the devel-
oping egg.
The slight excess of males produced in crosses
of the type XX 2 X XY $ that involve Peten
fish can mainly be attributed to two pedigrees.
In addition, eight other males are known to be
genetic sex reversals, that is, XX males (Table
25).
Platyfish with the XY constitution always dif-
ferentiate into males regardless of the population
from which the chromosomes have been de-
rived; when mated with XX females from their
own or from different populations, 66 males
(YY), all but two of which were wild-caught,
sired a total of 3,479 young, all of which were
males (Table 23). But when ten of the same
males were mated with WY females, their
offspring were of both sexes and of equal
frequency.
Crossing Over between Sex Chromosomes
In many matings, the sex chromosomes of
the parents were marked by pigment genes so
that specific patterns were restricted to one sex.
Phenotypic exceptions represent either cross-
overs or sex reversals. Without additional
crosses, however, these cannot be distinguished.
In four cases, nevertheless, fish showing color
patterns of the opposite sex could be classified
as sex reversals without further matings (see
footnote,2 Table 25).
Crossing over between W and Y chromosomes
was demonstrated in two out of 1,334 fish
(0.2%). This value is nearly identical with the
frequency of crossing over between the X and
Y chromosomes (Table 24). Nine out of 22
exceptions among 5,136 XX or XY offspring
were so identified (0.2%). If half of the un-
tested exceptions are also considered crossovers,
the frequency is raised to about 0.3 per cent.
This rate is similar to the one reported by Bel-
lamy & Queal (1951) for their domesticated
platyfish stocks. These authors found that
roughly 0.5 per cent, of their fish were excep-
tions of which about one-half were crossovers
1965]
Kallman: Genetics and Geography of Sex Determination in Xiphophorus maculatus
173
and the other half sex reversals. These values
are lower than those of Gordon (1937 a), who
estimated the frequency of crossing over be-
tween the W and Y (= Z) chromosomes to be
1 per cent.
Crossing over between heterochromosomes
has also been found in the egg-laying cyprino-
dont, Oryzias latipes, which has an XX-XY
mechanism. Yamamoto (1964) reports that in
normal males, the incidence of crossing over
between pigment gene R and the sex-differential
locus or segment is 0.2 per cent., while in XY
females (produced by treating newly hatched
XY fish with estrone) crossing over occurs in
1 per cent, of all cases.
In spite of the rarity of crossing over, in at
least one brood there were two cases (ped.
1498 a, Table 24). In two pedigrees crossovers
were accompanied by other exceptional fish
(Table 24). Unfortunately they were not tested
and their genotypes are not known. If they were
crossovers, some sort of genetic factor may be
present that greatly increases the frequency of
crossing over. Such a factor is perhaps opera-
tive in the Peten fish; an unexpectedly high
number of crossovers occurred among their de-
scendants (among the 602 offspring of 9 XY
Peten males there were five crossovers). If the
exceptional sibs of the crossovers were sex re-
versals, however, the events would appear to be
related, since sex reversals are also very rare.
In this connection, the statement by Bellamy &
Queal (1951) that crossover WY females give
rise to an increased number of exceptional WY
males is significant. Unfortunately, these in-
vestigators did not publish their complete data.
Perhaps under certain circumstances crossing
over involves in part the sex differential segment
of the sex chromosome.
Sex Reversal
All the fish in Table 25 possessed pigment
patterns that permitted them to be assigned a
specific sex chromosome constitution. Of the
exceptional individuals, 103 are considered
without question to be sex reversed, that is, to
have the phenotype of one sex and the genotype
of the other. The genotypes of 17 fish remain
unidentified, and these are the same 17 untested
exceptions that were listed in Table 24.
The incidence of sex reversals in our matings
is slightly more than 1 per cent. (Table 25).
The data, however, are strongly biased in favor
of the exceptions. Not only were many found
among the highly inbred Jamapa strains, but
broods of Jp 163 A and B in which no excep-
tions occurred were not necessarily recorded,
while all broods with sex reversals were, of
course, counted. Moreover, many XX males
were the result of the selective mating of sex-
reversed fish. If the inbred Jamapa fish and the
offspring of sex reversals (ped. 1580 and 1595
in Table 14; ped. 1685, 1570, 1686, 1687 and
1724 in Table 15) are omitted from Table 25,
one may obtain a better estimate of the fre-
quency of sex reversal. The number of XX
females and males then becomes 1,781 and 8,
respectively, and the number of XY males and
females 5,404 and 4, respectively. With this
correction, the number of sex reversals is 41
(4 XY 2 , 8 XX $ ,29 WY $), 36 of which
occurred in three pedigrees. The total frequency
of sex reversal then becomes 0.5%.
All 30 XX males can be traced back to two
fish. Peten male 1341-16 gave rise to six excep-
tions in a single brood, and Peten female 1341-1
was the progenitor of the remaining 24 (Table
15). Since both Peten fish were collected in the
same seine haul, they may be closely related and
perhaps all XX males have descended from a
single fish.
Of the 44 XY females, 40 were discovered
among the inbred Jamapa strains. Again, the
appearance of exceptional fish is not a random
event, since five females gave rise to 36 sex
reversals (Table 5) . Three XY females occurred
in the same brood of Grijalva fish (Table 3).
All but two of the 29 WY males occurred in
Gordon’s (1951 a) cross in which the entire
WY class differentiated into females (ped. 274,
Table 20). Of the 17 unexplained exceptions,
1 3 occurred in six pedigrees associated with
crossovers or other exceptional individuals. Sex
reversals are thus not isolated events, but are
definitely concentrated in certain pedigrees.
Although the phenomenon of sex reversal has
been demonstrated and studied extensively in at
least three species of cyprinodont fishes, the
medaka, Oryzias latipes, the guppy, Poecilia
reticulata, and Xiphophorus maculatus, it is
still not well understood. Almost all of the ex-
planations offered to account for sex reversals
in these fishes can be considered as a variation
of an idea that originated with Winge (1934).
He suggested that in the guppy there are many
genes on the autosomes working either in a male
or female direction and that in rare cases, per-
haps through crossing over, many “potent” genes
favoring one sex become located in one auto-
some and that such an autosome then has a
disproportionate effect on sex-determination.
Yamamoto (1963), in his discussion of sponta-
neous sex reversals in the medaka, states that
the ratio of the sum of male- to the sum of
female-determining genes on the autosomes of
a population has a mean around which varia-
Table 17. Sex Ratio and Inheritance of Pigment Pattern Among the Offspring of Six Wild-caught Female Xiphophorus inaculatus from
Rio de la Pasion (Sebol)
174
Zoologica: New York Zoological Society
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Kallman: Genetics and Geography of Sex Determination in Xiphophorus maculatus
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tion takes the form of a normal distribution
curve. According to Yamamoto, the Y chromo-
some shifts this ratio decidedly toward the
male and the X toward the female. The rare sex
reversals are those individual variants at the
extreme right or left of such a curve. Similarly,
Anders & Anders ( 1963) and Oktay (1959 a, b)
attribute the occurrence of XY females or XX
males in the platyfish to the effects of autosomal
sex genes. They visualize that on rare occasions
fortuitous combinations of autosomes possessing
a large number of male- or female-determining
genes override the switch mechanism of the sex
chromosomes. Oktay suggests that the high
incidence of XX males in one of her stocks
resulted from the presence of many autosomal
genes with a male tendency. As she points out,
some support for such a view is provided by the
fact that when XX males are outcrossed to un-
related females, very few sex reversals are
found among the offspring. Similar observations
have been made by Aida (1936) in the medaka
and by Winge (1930, 1934) and Winge &
Ditlevsen (1948) in the guppy.
Yamamoto (1963) has also pointed out,
however, that the medaka has 24 pairs of
chromosomes and that the possible number of
germ cells with different configurations of auto-
somes is 246. If there are many autosomal genes
that influence sex determination, the chance of
obtaining the necessary fortuitous autosomal
combinations to effect sex reversal is small. The
haploid number for the platyfish is also 24
(Friedman & Gordon, 1934). The occurrence of
sex reversal, therefore, should be a rare, isolated
event and the offspring of a sex-reversed indi-
vidual should be normal. But as our experi-
ments have demonstrated, and also those of
Anders & Anders (1963) and Oktay (1959 a, b),
just the opposite is true. These observations
cannot be reconciled with the theory of a large
number of autosomal male and female sex
genes. Oktay’s original XX male was found
among the first backcross generation between
two unrelated platyfish stocks. We may, there-
fore, assume that there was considerable genetic
diversity. Yet when this fish was bred, more XX
males occurred. When they were mated with
their sisters, a stock was established in which
both sexes were characterized by the XX con
stitution. One would expect that after nine gen-
erations of inbreeding the percentage of males
would have increased considerably and that the
sex ratio would have become stabilized with the
increasing homozygosity, but this was not the
case. Although Aida (1936), in Oryzias, was
able to increase the percentage of XY males
through inbreeding and selection, so that in
176
Zoologica: New York Zoological Society
[50: 13
Table 18. Sex Ratio and Inheritance of Pigment Pattern in Crosses Involving Wild-caught
Xiphophorus maculatus from the Rio San Pedro de Martir (Carmelita)
Parents
Offspring
Ped.
No.
Female
Male
Females
Males
1395a
Jp
XSp X Sp
1342-11
A+T +
Sp
19
Sd
Sr
+
Sp
14
Sd
Sr
+
1395b
Gp
XstXsp
1342-11
*+ Y +
9
10
—
—
5
4
—
—
1399a
Jp
XSp XSp
1342-12
Y+ Y+
—
none
—
—
38
—
—
—
1399b
Gp
XSd XSp
1342-12
Y Y
1 + 1 +
—
none
—
—
28
22
—
—
1455
Jp
XSp XSp
1342-13
y y
—
none
—
—
27
—
—
—
1405a1
1342-3
W+Y +
1342-13
y y
—
—
—
4
—
—
—
7
1405b1
1342-4
W+ Y+
1342-13
y y
—
—
—
3
—
—
—
2
1521
JP
XSd Xsd
1405a-12
y+
—
none
—
—
—
—
—
552
1465
1405a-2
W+ Y +
Jp
YSv YSr
27
—
25
—
13
—
22
—
1514
Jp
xSdxSd
1405b-l 1
Y+ Y +
—
none
—
—
—
1
—
322
1449
1 405b- 1
W+ Y+
TP
*Sp YSr
23
—
18
—
13
—
18
l3
1445
Jp
XSp XSp
1342-14
Y Y
+ +
—
none
—
—
32
—
—
—
1 4 1 21
1342-5
W+ Y +
1342-14
y+ y+
—
—
—
7
—
—
—
6
1518
Jp
YSd X Sd
1412-11
y+
—
none
—
—
—
2
—
522
1472
Jp
XSp XSp
1342-15
y y
—
none
—
—
80
—
—
—
1425a1
1342-6
IV+ Y+
1342-15
y y
—
—
—
3
—
—
—
3
1425b1
1342-7
W+Y+
1342-15
y y
+ +
—
—
—
4
—
—
—
11
1528
JP
XSd XSd
1425a-12
y y
+ -f
—
none
—
—
—
—
—
382
1526
Jp
XSp XSp
1425b- 11
—
none
—
—
31
—
—
—
1380a
1342-1
W Y
YY + I +
Jp
XSp Y Sr
11
—
9
—
7
—
15
—
1380b
1342-2
W Y
n + 1 +
Jp
*Sp YSr
14
—
17
—
13
—
8
—
1 Only a few fish picked at random when 10 days old were raised to maturity. All other fish were sacrificed for another
experiment.
• Jamapa Sd usually not expressed in inter-river crosses.
3 Pigment pattern in this pedigree weakly developed; this wild-type male was sacrificed before its pigment pattern appeared.
some broods males outnumbered females sig-
nificantly, neither he nor Winge (1934) were
able to stabilize the percentage of males. In
these strains of the medaka and the guppy, mat-
ings of different males and females of the same
generation gave rise to highly variable sex ratios.
These observations suggest that Aida, Winge and
Oktay had selected for a gene complex that
made the sex-determining mechanism of the sex
chromosomes highly labile and susceptible to
other, still unknown, factors. Their data cer-
tainly do not demonstrate the existence of auto-
somal genes that effect sex per se.
Rare combinations of autosomal sex genes
could hardly account for the sudden appearance
of broods in which the entire XY class of fish
consisted of sex-reversed females, especially
since no exceptions had ever occurred previously
in the strains [Table 5; see also MacIntyre
(1961) and Anders & Anders3 (1963)]. If
these XY females were indeed the result of the
3 It is important to note that the platyfish stock of
Anders & Anders was derived from the Jamapa strains
which Dr. Myron Gordon brought to Europe more
than 15 years ago.
accumulation of “autosomal female” genes, one
would expect that under the inbreeding regime
to which the Jp 163 lines had been exposed, a
few exceptional females would have occurred
in earlier generations.
The results of several other crosses are also
in conflict with the theory of autosomal sex
genes. In Fx generations of three crosses be-
tween Jamapa and Peten fish, several XX males
were detected. Additional XX males (in still
higher frequency!) occurred in the first and
second backcross generation to Jamapa fish
(Table 15). This series of crosses confronts us
with the paradoxical situation, that on the one
hand a large number of autosomal female
genes must be attributed to the Jamapa strains,
since XY females occur in them, while, on the
other, the occurrence of XX males in the Fx,
1st and 2nd backcross generations must be
attributed to autosomal male genes.4
4 Aida ( 1936) suggested that XX males in the medaka
may be the result of a lowering of the female-determin-
ing potency of the X chromosome. Conceivably this
could take place through translocation or crossing over
involving part of the sex differential segment. An un-
usual X chromosome could not be the explanation for
1965]
Kallman: Genetics and Geography of Sex Determination in Xiphophorus maculatus
177
Table 19. Sex Ratio and Inheritance of Pigment Pattern Among the Offspring of Wild-caught
Xiphophorus maculatus from the Rio Grijalva
Parents
Offspring
Ped.
No.
Female
Male
Females
Males
Sd
Sp
Sd
+
Sp
Sd
Sp
+
450
Gp-1
W+X +
unknown
14
—
7
10
—
—
21
512
450-1
w+ Y +
45 lb-1 1
—
5
—
—
14
—
8
605
518-1
x+xSP
512-11
YadY+
—
none
—
6
2
2
All
Gp-1
W+X+
Gp-1 2
YSdY+
—
7
15
—
18
—
18
511
476-1
x+x+
477-11
X+ Yad
—
1
35
—
23
— ■
—
475
450-3
X+XsP
Gp-1 5
X+Y +
2
—
7
7
—
—
—
518
475-4
x+x+
475-14
XSPY +
27
—
—
—
—
—
40
476
450-2
x+xSP
Gp-1 4
X+ Y +
2
—
2
1
—
—
451a
Gp-2
X+XSP
Gp-1 3
Y+ Y+
—
none
— ■
21
—
—
25
451b
Gp-2
Gp-1 2
Y+ Ysd
—
none
—
6
2
2
2
The 27 wild type fish of pedigree 274 (Table
20), which apparently have the WY genotype,
were first reported by Gordon (1951 a), who
suggested that the “Y” chromosome of the
Coatzacoalcos strain was stronger than the Y
the sex reversals in the Peten x Jamapa crosses, how-
ever, since some XX males of the backcross generation
had inherited both X chromosomes from the Jamapa
strain. The occurrence of XX males, therefore, is not
dependent upon the presence of a sex chromosome de-
rived from the Peten fish.
of the other stocks and epistatic to the W
chromosome. This explanation has been ac-
cepted by most authors, although no additional
experiments to test this hypothesis were ever
performed.
Unfortunately, sex determination in these
cyprinodont fishes has been treated as if it were
a question of merely adding up the strength of
a large number of male and female factors.
With such an approach, almost any exception
can be explained by juggling figures and assign-
Table 20. Sex Ratio and Inheritance of Pigment Pattern Among the Descendants
of Wild-caugh Xiphophorus maculatus from the Rio Coatzacoalcos
Parents
Offspring
Ped.
No.
Female
Male
Females
Males
Sd Sd
Sr Sd
270
JP
XarXar
Cp-11
XSd ^ +
Sd
461
Sp
Sr
N
N
Sp
+
Sd
Sp
N
N
Sp
+
541
272
Jp
*sP xsa
Cp-12
z+y+
—
4
—
—
—
—
52
—
5
—
—
—
32
—
272-1
YSdx+
272-11
*Spr+
—
202
222
273
Jp
YSpYSd
Cp-13
x+y+
—
8
—
—
—
—
102
—
1
—
—
—
72
—
273-1
xSdx + 2
273-11
*SP Y +
—
192
1
132
269
Jp
XSrXSr
Cp-16
x+yn
—
—
72
—
—
—
—
—
—
—
50
—
—
333
JP
xSr x8r
269-11
XSr Ytf
—
—
43
—
—
—
—
—
—
—
29
—
—
341
Jp
XSr *Sr
333-11
Y Sr Yn
—
—
15
—
—
—
—
—
—
—
15
—
—
274
Bh
W+ YSp
Cp-18
X+ Y +
—
—
—
—
—
—
23
— -
59
—
—
—
27
275
Cp-2
XNX +
Cp-15
X+ Y +
—
—
—
13
—
—
14
—
—
14
—
—
23
300
275-1
XNX+
275-11
*nY ,
—
—
—
20
—
—
—
— ■
—
7
—
—
11
298
Cp-3
XSax+
unknown
11
—
—
—
—
—
12
11
—
—
—
—
11
326
Cp-6
V+
unknown
9
—
—
—
—
3
—
3
—
—
—
7
—
391
326-1
300-11
X»Y+
—
—
—
6
5
—
—
7
—
—
—
—
7
299
Cp-9
v+
unknown
12
—
—
—
—
11
—
—
12
—
—
—
19
1 Fish sacrificed before Sr pattern developed.
2 Nonpenetrance of Jamapa Sd in inter-river hybrids.
178 Zoologica: New York Zoological Society [50:13
Table 21. Sex Chromosome Constitution
OF
Wild-caught Xiphophorus
maculatus
Location
Number of Females
Number
of Males
WW
WY
WX
W?1 XX
X?1
XY
YY
Belize River
—
4
—
— —
—
—
2
New River
—
1
—
— —
—
—
2
Rio Hondo System
Rio Hondo, San Antonio, 1954
- —
3
—
— 2
—
1
—
Rio Hondo, Douglas, 1963
1
8
—
— —
—
1
3
Aguada Corriental (Tikal)
—
8
—
— —
—
—
6
Lake Peten
Lake Peten, Flores, 1954
—
—
1
— —
—
3
1
Lake Peten, Remate, 1963
—
4
1
1 —
—
4
3
Rio Usumacinta System
Rio de la Pasion, Sebol
■ — ■
4
—
— 1
1
7
—
Rio San Pedro de Martir, Carmelita
—
7
—
— —
—
1
5
Rio Grijalva
—
—
1
— 1
—
2
2
Rio Coatzacoalcos
—
—
—
— 4
—
6
—
1 The analysis for two fish is incomplete. Critical crosses to identify the second sex chromosome were not performed.
ing arbitrary valances to chromosomes or genes.
Some of the problems involved in devising a
workable scheme for polygenic sex determina-
tion have been pointed out by Kosswig (1964).
The experiments of Yamamoto (1953, 1955,
1958, 1959 a and b, 1962) and Dzwillo (1962)
on fishes and of Humphrey (1945, 1948) and
Mikamo & Witschi (1963) on amphibians have
shown that functional sex reversals can be pro-
duced artificially when the developing indi-
vidual or gonad primordium is exposed to suit-
able agents before a critical period, presumably
the limited time during which the sex chromo-
somes act. The W chromosome in amphibia and
the X chromosome in the medaka seem not to
be necessary for the production of eggs, since
functional YY (=ZZ) females can be pro-
duced. The Y chromosome is not needed for
the normal functioning of the entire male repro-
ductive apparatus, since functional males with
the WW (amphibia) or XX (fish) constitution
can be obtained. As Yamamoto has pointed out,
the action of the sex genes or sex chromosomes
may be restricted to the critical period of sex
differentiation; thereafter they have no apparent
function. We have already indicated above that
Oktay’s, Winge’s and Aida’s experiments sug-
gest selection for a gene complex that makes
the sex-determining action of the sex chromo-
some highly labile, but other causes cannot be
excluded. That sex reversals in platyfish are
often not isolated events suggest that relatively
few autosomal genes are involved. As new cyto-
logical methods for chromosome analysis have
become available, many gonadal and sexual
abnormalities in man and in other animals have
been traced to autosomal gene mutations, non-
disjunction, translocation or loss of a chromo-
some. Sex reversal in the platyfish may be due
to similar causes, but virtually nothing is known
about the chromosomes of this species except
that the diploid number is 48.
Identity of the Y and Z chromosome
Until Gordon announced that platyfish of the
Rio Jamapa, Rio Coatzacoalcos and Rio Papa-
loapan were homogametic in the female sex and
heterogametic in the male, the sex chromosome
constitution of the “domesticated” stocks of
unknown geographic origin was conventionally
written as WZ 2 and ZZ $ . In 1946 and 1947
Gordon suggested that the “Z” chromosome of
the domesticated races might be identical with
the Y chromosome of wild-caught Mexican fish
and that the usage of ZZ for the domesticated
male might be discontinued and YY substituted.
In a series of intra-specific crosses involving
several stocks of domesticated and wild-caught
fishes, Gordon (1951a, 1952) and Oktay
(1959 a) showed that the Z chromosome and
the Y chromosome were equivalent.
However, Kosswig & Oktay (1955), Oktay
(1959 a and b), Zander (1962, 1964) and
Anders & Anders (1963) have not only retained
the symbol “Z” to denote the chromosome de-
termining maleness in the domesticated races,
but have also extended its use to those wild
stocks in which the male is homogametic.
1965]
Kallman: Genetics and Geography of Sex Determination in Xiphophorus maculatus
179
Table 22. Summary of Sex Ratios of Wild-caught Platyfish and Their Offspring
No. and
type of
crosses
Origin of
fish
Table
Matings
1 P
9 $
WX X XY
9 S
WY x XY
9 S or
WY X YY WX X YY
Offspring
9 $
XX X XY
9
$
9
S 9
$
9
$
3
II
2 i*
Belize River
6
64
54
0.85
>0.3
2 h*
Belize River
6
72
84
0.92
>0.3
3 i
New River
7
92
80
0.84
>0.3
5 h i
Hondo
8, 9, 10
81
73
0.4
>0.5
21 i
Hondo
8
55
49
0.34
>0.5
112 h
Hondo
10
376
280
14.0
<0.01
2 h
Hondo
10
48
53
0.36
>0.5
2 i
Tikal
12
92
73
1.52
>0.2
9 h
Tikal
12
251
192
8.1
<0.01
1 h
Tikal
12
70
16
1.9
0.1
253 h i
Peten
13, 14, 15
854
945
6.6
<0.01
8 h i
Peten
15
244
288
1.6
>0.2
4 h
Peten
15
183
61
0.0
1.0
164 h i
Sebol
16, 17
432
394
1.75
>0.1
3 i
Sebol
17
130
118
0.5
>0.3
4 h i
Sebol
17
136
123
0.54
>0.3
4 h
Sebol
17
136
50
0.3
>0.5
4 h
Carmelita
18
144
110
2.27
>0.1
2 h
Carmelita
18
38
23
3.16
>0.05
5 i
Carmelita
18
21
29
1.3
>0.2
8 h
Coatzacoalcos
20
242
206
2.8
0.1
6 i
Coatzacoalcos
20
116
132
1.03
>0.3
127
389
127
447
407 1,278
1,126
1,763
1,773
* i: intrapopulation cross, h: interpopulation cross.
1 Sex ratio of one cross (ped. 551, Table 8) differs significantly from a 1:1 ratio, x2 = 4.6, .05 > p > .02.
2 Sex ratio of ped. 1520 (Table 10) differs significantly from a 1:1 ratio, x2 = 5.4, p = .02.
3 Sex ratios of two crosses deviate significantly from expected 1:1 ratio, ped. 532 (Table 13), x2 = 13.4, p < .01; ped. 1485
(Table 15), x2 = 6.06, .02 > p > .01.
4 Sex ratio of ped. 1362a (Table 16) differs significantly from a 1:1 ratio, x2 = 8.9, p < .01.
Kosswig & Oktay ( 1955) and Anders & Anders
(1963), although agreeing with Gordon that in
intraspecific hybrids the “Z” and Y chromo-
somes behave identically, maintain that a differ-
ence between “Z” and Y chromosomes can be
demonstrated in certain interspecific crosses. In
particular, they refer to matings between female
swordtails, X. hellerii, which appear to possess
a polygenic sex-determining system, and “ZZ”
homogametic domesticated X. maculatus males
(Bellamy, 1922; Kosswig, 1928, 1931, 1934,
1939). The sex ratio of the F, hybrids, all of
which have inherited a “Z” chromosome, was
highly variable; in some crosses only 10 per
cent, of the offspring were females, in others
there were as many as 50 per cent. In addition,
the sexual development of 17-45 per cent, of all
hybrids (of both sexes) was abnormal, exhibit-
ing greatly delayed maturation or arrested go-
nadal development. On the other hand, the “Y"
class hybrids obtained by mating a X. hellerii
female with a XY platyfish from the Rio Jamapa
consisted of 90% sexually indifferent fish, 6%
fertile females and 4% fertile males (Gordon &
Rosen, 1951). Similar results were recently re-
ported by Anders & Anders (1963). Because of
the great disparity in the sex ratio and the de-
gree of gonadal development between the Y and
Z class hybrids, Kosswig & Oktay (1955) and
Anders & Anders (1963) conclude that the Z
and Y chromosomes are distinct entities.
There are, however, several crosses^ that
clearly contradict this view. Kosswig & Oktay
(1955) briefly described two crosses between
180
Zoologica: New York Zoological Society
[50: 13
Table 23. Sex Ratios of Matings Between XX Females and YY Males
Parents
Offspring
Females
Males
Females
Males
Strain or
Number
Strain or Population
Number
Population
2
Jp 163; Jp 30
2
Belize River
0
304
2
Cp; Jp 163
2
New River
0
184
2
Hondo, 1954
2
Hondo, 1954
0
101
14
Cp; Jp 163 A, B; Jp 30
12
Hondo, 1963
0
648
2
Sebol
1
Hp-1
0
85
23
Gp; Jp 163 A, B; Jp 30
19
Tikal
0
903
3
Cp; Peten
3
Peten, 1954
0
105
6
Gp; Jp 163 A, B
5
Peten, 1963
0
260
8
Hp-2; Jp 163 A, B; Sebol
8
Sebol
0
381
10
Gp; Jp 163 A, B
9
Carmelita
0
438
2
Gp
3
Grijalva
0
70
74
66
0
3,479
Sex
Ratios of Matings Between WY Females and Some of
the Same
YY Males
Total
2
Np
2
Hondo, 1963
48
53
101
2
Tikal
2
Tikal
92
73
165
3
Sebol
3
Sebol
130
118
248
5
Carmelita
3
Carmelita
21
29
50
12
10
291
273
564
X. Iiellerii females and XY maculatus males5 in
which the T-class hybrids consisted of 66 fe-
males and 59 males. This is a ratio indistinguish-
able from the sex ratio of the “Z” class Fj
hybrids in some of Kosswig’s (1931) earlier
work, but quite different from the observations
of Gordon and Rosen and Anders and Anders
(Table 26). With these crosses the alleged dif-
ference between the “Z” and Y class hybrids dis-
appears completely. Kosswig & Oktay (1955)
minimize the importance of these findings by
attributing them to variables introduced by the
X. hellerii strain.
Zander (1964) has presented an extensive
series of experiments which clearly show that
the sex ratio of platyfish-swordtail hybrids de-
pends in part upon the subspecies from which
the swordtail parent was taken. He found that
the number of males in the “Z” class ranged
from 58 to 100 per cent., in the Y class from
27 to 95 per cent., and in the X class from 0 to
54 per cent.
In other crosses involving heterogametic
platyfish females of domesticated stocks and
swordtail males, all “Z” class hybrids differen-
6 These platyfish males are also descendants of the
Jamapa fish.
tiated into males (Kosswig, 1928; Kosswig &
Oktay, 1955; Senglin, 1941). Kosswig & Oktay
attribute the absence of females among the “Z”
class to cytoplasmic factors or to variables in-
troduced by the swordtail strain. It is interesting
to note that the sex ratio of the X class hybrids
is just as variable (Table 26).
The value of hybrid data in elucidating the
factors involved in sex determination in Xipho-
phorus may be seriously doubted in view of
the many physiological, developmental, endo-
crinological, behavioral and anatomical abnor-
malities that have been recorded for these hy-
brids (Atz, 1962; Clark, Aronson & Gordon,
1954; Gordon, 1937 b, 1948; Gordon & Rosen,
1951; Kosswig, 1929; Oztan, 1960, 1963;
Rosen, 1960; Sengiin, 1950; Tavolga, 1949).
In these hybrids, variable sex ratios and ab-
normal gonadal differentiation are manifesta-
tions of a general breakdown of developmental
homeostasis resulting from the juxtaposition of
two dissimilar genomes. Moreover, it is diffi-
cult to interpret the sex ratios of the hybrid
crosses when that of X. hellerii itself varies
greatly; in certain strains males predominate,
in others females (Breider, 1935; Peters, 1964;
Kosswig, 1964).
1965]
Kallman: Genetics and Geography of Sex Determination in Xiphophorus maculatus
181
At the most one can conclude (Table 26)
that the sex ratios as well as the degree of gonadal
differentiation of the hybrids may very well
depend upon the stock of swordtails used. None
of these Fj data suggest that the “Z” chromo-
some is different from the Y, since no differ-
ence in their genetic behavior has ever been
reliably indicated.
Anders & Anders (1963) suggest that
X. maculatus has evolved from an ancestor
with a polygenic sex-determining system and
that the step from the polygenic stage to one
involving sex chromosomes has occurred twice,
once leading to the WZ-ZZ and once to the
XX-XY mechanism. According to these authors,
during the polygenic stage all chromosomes
carried male- and female-determining factors,
but when the sex chromosome mechanism
evolved, the genes working in the direction of
the homogametic sex were lost from the chromo-
some determining the heterogametic sex. Thus
female (“F”) factors were eliminated from the
Y chromosomes and male (“M”) factors from
the W, creating two strong sex-determining
chromosomes. The “Z” and X chromosomes
retained “M” and “F” factors.
As support for their hypothesis Anders &
Anders (1963) report that YY males (produced
by mating a rare XY female with a XY male)
mature 3-4 weeks later than their XY brothers
and suggest that the X chromosomes, in addi-
tion to carrying “F” genes, also possess genes
that control the “normal” onset of sexual matu-
ration in the male. Just how these observations
provide evidence for or against the presence of
“M” factors in the X chromosome is not clear.
That YY (Sr Sr) males, which are fully fertile
and functional, mature slightly later and there-
fore grow larger, may be a metabolic effect re-
lated to the presence of two Y chromosomes.
Gordon & Gordon (1954) reported that Sr
males of the Jamapa population were larger and
relatively more deep-bodied than Jamapa males
with other pigment patterns. Such an effect
could be produced by a gene linked to Sr that
influences the time of sexual maturity. In YY
males homozygous for the Sr allele, this effect
might well be accentuated. The occurrence of
males with different body proportions related to
the age of sexual maturation (as well as the
extent to which other secondary sex characters
are developed), is a characteristic feature of the
genus Xiphophorus and other poeciliid genera
(Rosen & Bailey, 1964). The polymorphism
exhibited by adult males probably finds its most
extreme expression in the swordtail, Xipho-
phorus pygmaeus nigrensis (Rosen, 1960).
The difference in the sex ratio of the hybrids
of hellerii and maculatus with “Z” and Y
chromosomes has also been used as evidence
that “F” genes are present in the “Z”, but absent
from the Y chromosome. As previously men-
tioned, however, the percentage of females in
the Y class was just as high as that in the “Z”
class in several crosses (Table 26). Zander’s
(1964) recent experiments show that the per-
centage of females is sometimes even higher in
hybrids belonging to the Y class — just the op-
posite of what the theory of Anders & Anders
would lead one to expect.
The occurrence of ZZ females and the ab-
sence of YY females has also been cited to sup-
port the presence of “F” genes in the “Z”
chromosomes; YY females do not occur, since
“F” genes are missing from these chromosomes.
But the “ZZ” females to which Anders refers
(Kosswig, 1931, 1936) were not X. maculatus
females; they were hybrids between the platy-
fish and the swordtail. 13 Since all crosses involv-
ing these two species have shown that the sex
chromosomes of X. maculatus do not manifest
themselves normally in the hybrids, the data
cannot be accepted as proof of the existence of
“F” genes in the “Z” and their absence from the
Y chromosome.
According to the theory of Anders & Anders,
exceptional WZ males would be relatively rare,
since the W chromosome possesses only “F”
factors and the Z chromosome both “M” and
“F” genes. However, exceptional WY males
have been reported on several occasions (Brei-
der, 1942; Bellamy & Queal, 1951; Oktay,
1959 a).
The simultaneous existence of W and X
chromosomes and homogametic and heteroga-
metic males in the majority of the platyfish
populations and the demonstration that the
male-determining chromosomes of X. maculatus
and X. variants can replace each other (Bel-
lamy, 1936; Gordon & Smith, 1938; Kosswig,
1935; Oktay, 1959 a, 1962), is excellent evi-
dence that the “Z” and Y are one and the same
chromosome.
Evolution of Sex-determining Mechanism
in Xiphophorus maculatus
Gordon ( 1952) thought that populations with
the WY-YY and XX-XY systems were geo-
graphically isolated and suggested that each
specialized mechanism arose independently
from an undifferentiated polygenic condition,
perhaps like the one that exists in the swordtail.
Anders & Anders (1963) presented an essen-
6 (hel § X mac $ ) 2 X [(hel 2 X mac $ )
2 X mac $ ] $
182
Zoologica: New York Zoological Society
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tially similar view which has already been dis-
cussed in the previous section. This view implies
that sex chromosomes did not develop in the
platyfish until the last million years and that
during most of the 350 million years that fishes
have existed the multitude of forms ancestral to
Xiphophorus and the poeciliids possessed no sex
chromosome mechanism. This seems most un-
likely, since sex chromosomes are widespread
elsewhere. The platyfishes possess 24 pairs of
chromosomes and it would be a remarkable
coincidence, indeed, if the same pair had inde-
pendently evolved into sex chromosomes not
only in the two hypothetical isolated platyfish
populations, but also in X. variants, the sex
chromosomes of which are homologous to W ,
X and Y of maculatus (Atz, 1959; Oktay, 1962).
Moreover, the geography of the area does not
provide any evidence that such a separation ever
existed in the past. The coastal plains of southern
Mexico and British Honduras are continuous
across the Peten district of Guatemala. The
large interior lakes and swamps of northern
Peten provide ready-made avenues of dispersal
between the Caribbean lowlands to the East
and the Gulf of Mexico coastal plain to the
West.
Rosen (1960) suggests that X. maculatus or
its immediate ancestor invaded its present
range from an area in northern Veracruz and
southern San Luis Potosi where the genus Xipho-
phorus seems to have originated. No significant
differences in morphological traits between
platyfish inhabiting each of the river systems
have developed (Gordon & Gordon, 1954;
Rosen, 1960), although the frequency of the
macromelanophore alleles and tailspot patterns
is different for every drainage (Gordon & Gor-
don, 1957). During the Pleistocene, the ocean
level may have been sufficiently low to permit
the movement of platyfish between river sys-
tems (Rosen, 1960). The difference in the fre-
quency of the pigment patterns would then be
of more recent origin.
The W and X chromosomes are found to-
gether in the center of distribution of X. macu-
latus in the Rio Grijalva and Rio Usumacinta
drainage. These rivers are contiguous near their
mouths and form the largest river system in
Central America. Both chromosomes are also
found in Lake Peten and Rio Hondo. The W
seems to be absent from the Rio Coatzacoalcos,
Rio Papaloapan and Rio Jamapa to the West
and the X may be missing from the New and
Belize Rivers at the eastern edge of platyfish
distribution. As more populations are examined,
this picture may change, but present evidence
thus indicates that the W chromosome has
184
Zoologica: New York Zoological Society
[50: 13
Table 25. Sex Chromosome Constitution of Male and Female Xiphophorus maculatus
WX
ww
WX
WY
XY
XX
WX
or
or
or
or
or
or
or
WY
WX
XX
WY
WY
YY
XX
XY
YY
YY
XY
XY
9 8
9
9
9
9
8
9 8
9 8
8
8
+o
o*
9
Np
232
Hp-1
64
61
Hp-2
305
307
(2)i
Gp
215
52 216
(2) (1)
Cp
201
223
(1)
Jp A, B
756
40 698
Belize
59
304
55
(Table 6)
New River
92
(1)
184
79
(Table 7)
Rio Hondo
29
101
15
(Table 8 )
Rio Hondo
110
1
50
4
(1)
37
691
97
(2)
(Table 9, 10)
Tikal
117
1
41
919
79
(Table 11, 12)
Peten
145
6
323
(Table 13, 14)
Peten
50
67
750
24
1 657
(3) (2)
(Table 15)
Sebol
95
38
70
61
207
715
101
25
(1)
(Table 16, 17)
Carmelita
438
(Table 18)
Rio Grijalva
62
133
(1)
(Table 19)
Rio Coatzacoalcos
27
23
226
209
59
(Table 20)
819
29
178
111
4 90
(2)
2,904
30
44 6,118
175
396
(6) (7) (2)
Total 10,915
1 The numbers in ( ) are untested exceptions that are either crossovers or sex reversals.
2 The numbers in italics represent fish that are considered sex reversals because they have been identified as such through
testcrosses or the circumstances of their occurrence made it virtually certain that they were, e.g., the Sd Sr females of the
Jp strains, the six Sp males of pedigree 1413 (Table 14), the three Sd females of pedigree 942 (Table 3) and the wild type
males of pedigree 274 (Table 20).
arisen from the X in the region of the Rio Gri-
jalva and Rio Usumacinta. The nature of this
genic or chromosomal change is still unknown.
The W chromosome may have evolved before
the New and Belize Rivers in the East were
occupied by the species, and the platyfish that
first invaded these rivers may already have pos-
sessed the WY-YY system. It seems much less
likely that the W chromosome arose in the
rivers of British Honduras. In this case, the
New and Belize Rivers would have been pene-
trated first by platyfish with a XX-XY mecha-
nism, the X would have been replaced by the
W chromosome and, finally, the W would have
spread westwards throughout the Rio Grijalva
and Rio Usumacinta systems.
The evolutionary implications of the change
from the X to the W chromosome are not clear.
The frequency of the three chromosomes should
remain constant, if germ cells carrying the W,
X or Y have equal opportunities of fertilization
and if WX, WY, XX, XY and YY individuals
leave the same number of offspring. Neverthe-
less, the W chromosome apparently arose from
the X and has become widespread, so a distinct
selective advantage must have been associated
with it.
The origin of the W chromosome should be
considered in relation to the unusual sex-deter-
mining mechanisms that have been discovered in
poeciliid fishes. In many species of this group,
a 1 : 1 sex ratio is not necessary, since each male
Table 26. Sex Ratio of Fi Hybrids Between Xiphophorus maculatus and Xiphophorus hellerii
Class:
1965]
Kallman: Genetics and Geography of Sex Determination in Xiphophorus maculatus
185
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186
Zoologica: New York Zoological Society
[50: 13
is constantly active in courting and attempting
to inseminate many females. One male can fer-
tilize a large number of females, and a single
insemination may be sufficient for several suc-
cessive broods. There is direct evidence that in
several species females greatly outnumber males.
In Gambusia (Krumholz, 1963) and in the
guppy (Haskins et cil., 1961), the number of
males becomes drastically reduced through pre-
dation. In at least two species of Poeciliopsis,
there are females that give rise to offspring of
both sexes, but there are other females that give
rise to all-female progeny and this all-female
condition is inherited (Miller, 1960; Schultz &
Miller, 1959; Schultz, 1961). Several of such
all-female strains have been perpetuated in the
laboratory for many generations. They do not
reproduce by gynogenesis, since paternal traits
are expressed in the offspring (Miller & Schultz,
1959; Schultz, 1961). Hubbs (1964) reports
that in two populations of Poecilia latipinna
examined, females outnumber males. Breeding
experiments in the laboratory indicate that the
sex ratio in favor of females has, at least in
part, a genetic basis. Poecilia formosa is an all-
female species that reproduces by gynogenesis
after mating with males of closely related spe-
cies (Hubbs & Hubbs, 1932; Hubbs, 1964; Kali-
man, 1962). An outstanding example that a 1 : 1
sex ratio is not necessary in poeciliids is pro-
vided by the P. latipinna and P. formosa popu-
lations of Brownsville, Texas. In this area
females of P. latipinna and P. formosa out-
number males 25-100: 1 (Hubbs, 1964).
In those species in which a 1 : 1 sex ratio is
evidently not necessary, and in which an excess
of females may even be advantageous, the sex-
determining mechanism could undergo an adap-
tive radiation and evolve into new specialized
systems. Not all such evolutionary experiments
might be successful, but those resulting in a sex
ratio favoring females would be strongly selected
for. The W chromosome of X. maculatus may
represent such an experiment. If this view is
taken, the polygenic system of X. hellerii should
not be considered primitive but a more special-
ized condition that arose from the XX-XY
mechanism. Sex chromosomes are not terminal
stages in evolution; like all other chromosomes,
they evolve and change through translocations,
inversions and deletions, and the function of sex
determination can be taken over by other chro-
mosomes (White, 1954). To consider the sex-
determining mechanism of the swordtail as
advanced is also in much better accordance
with the fact that X. hellerii is the most wide-
spread, ecologically diverse and specialized
member of the genus (Rosen, 1960).
The XX-XY and the WY-YY systems of
X. maculatus cannot be regarded as two distinct
sex-determining mechanisms. The W and X
chromosomes occur together in many popula-
tions and breeding experiments show that fish
with different chromosome constitutions breed
and in all ways are compatible with each other.
The W , X and Y chromosomes of X. maculatus
are also homologous to the X and Y chromo-
somes of X. variants. The two species undoubt-
edly evolved from a common ancestor with an
XX-XY mechanism. Most likely, the W arose
from the X chromosome somewhere in the Rio
Usumacinta-Rio Grijalva system.
Summary
1 . The platyfish, Xiphophorus maculatus,
lives in rivers of the Atlantic coastal plain from
British Honduras westwards to the Rio Jamapa,
Veracruz, Mexico.
2. Genetic studies during the last 35 years
have shown that certain strains and populations
of X. maculatus are heterogametic in the female,
while others are heterogametic in the male sex.
All domesticated stocks of unknown geographic
origin and populations from British Honduras
were found to possess the WY $ -YY $ system,
but those from the Rio Jamapa, Rio Coatza-
coalcos and Rio Papaloapan in Mexico the
XX 2 -XY $ system.
3. Although sex chromosomes have never
been identified cytologically in this species, their
presence can be inferred from the behavior of a
number of sex-linked pigment patterns. X. macu-
latus with different sex-determining mechanisms
are morphologically indistinguishable and hy-
bridize readily; the offspring are fully fertile.
Fish with the WY, WX and XX constitutions
differentiate nearly always into females and
those that are XY or YY into males.
4. Eight stocks (6 XX-XY, 2 WY-YY ) of
known geographic origin have been maintained
in the laboratory for many generations; one,
Jp 30, inbred since 1939 for more than 42 gen-
erations by mating brother-to-sister. In all
strains, males and females occur in equal
numbers.
5. Platyfish were collected in all major drain-
age systems and their sex chromosome consti-
tution analyzed, in order to determine the
distribution of the X and W chromosomes. Fish
from the New River and Belize River of British
Honduras possess the WY-YY mechanism, but
since the sample consisted of only 9 fish, the
picture may change as more individuals are
collected. In the Rio Hondo system (British
Honduras, Guatemala) XY (2) and YY (9)
1965]
Kallman: Genetics and Geography of Sex Determination in Xiphophorus maculatus
187
males, XX (2), WY (19) and WW (1) females
were collected. The fish from Lake Peten (Gua-
temala) consisted of WY (4) and WX (2)
females and XY (7) and YY (4) males. The
Rio Usumacinta-Rio Grijalva system, which is
the largest in Central America, was sampled at
three widely separated points. In the Rio de la
Pasion WY (4) and XX (1) females and XY
(7) males were collected; in the Rio San Pedro
de Martir WY (7) females, YY (5) and XY ( 1 )
males and in the Rio Grijalva WX and XX
females (1 each) and XY and YY males (2
each) were found. No YY males and no W
chromosomes are known from the Rio Coatza-
coalcos, Rio Papaloapan and Rio Jamapa. The
area in which both W and X chromosomes
occur together is approximately 60% of the
platyfish range.
6. Fish with the various sex chromosome
combinations were found in the same seine
haul and breeding experiments with females that
were gravid when collected indicate that XY and
YY males fertilize all females, regardless of their
sex chromosome constitution.
7. The sex-determining mechanism of X. ma-
culatus is a stable one. When 66 YY males were
mated to XX females from their own or from
different populations, 3,479 offspring were ob-
tained, all males. But when 10 of the YY males
were bred with WY females, offspring of both
sexes were produced in equal numbers. Crosses
between WX females and XY males resulted in
a 3:1 sex ratio. Crosses between WY females
and YY or XY males, WX females and YY
males, and between XX females and XY males,
regardless of whether or not the parents be-
longed to the same population, gave rise to a
1 : 1 sex ratio with the following exception.
Matings between WY females of the Rio Hondo
system and XY males of other locations pro-
duced an excess of females.
8. Crossing over between the W and Y
chromosomes in females and between the X and
Y chromosomes in males occurs at a frequency
of approximately 0.2 per cent.
9. The frequency of sporadic genetic sex re-
versals (WY s , XX $ , XY 2 ) is about 0.5 per
cent. Sex reversals do not always occur at ran-
dom, but are concentrated in certain strains and
pedigrees. They may be found (a) in rigidly
inbred stocks, (b) among the offspring of het-
erozygous parents belonging to the same or
(c) to different populations. Some crosses sug-
gest that sex reversals and crossing over may be
related events. Genetic sex reversals in platyfish
have been attributed to fortuitous combinations
of autosomal “male” and “female” determining
genes that override the switch mechanism of the
sex chromosomes. Such autosomal “sex” genes
cannot account for some of the sex reversals
obtained in these experiments.
10. The sex-determining mechanism of popu-
lations or strains in which males are homoga-
metic is sometimes written WZ 2 -ZZ s ■ Several
authors believe that the “Z” chromosome is
different from the Y of fish with the XX-XY
system. In intraspecific crosses no difference be-
tween the Y and “Z” chromosomes can be
demonstrated. It is claimed that the difference
between the Y and “Z” chromosomes becomes
apparent in interspecies crosses with the sword-
tail, X. hellerii. A critical review of the macu-
latus X hellerii crosses, however, has failed to
reveal any consistent difference between the
"Z” and Y class hybrids.
1 1 . Since the W and X chromosomes and
homogametic and heterogametic males occur to-
gether over a vast area, it is best to eliminate
the symbol “Z”. Retaining it might lead to the
misunderstanding that X. maculatus possesses
two separate sex-determining mechanisms.
12. The WY-WX-XX-XY-YY system of X.
maculatus is a single integrated sex-determining
mechanism that arose from an ancestor which
was probably XX-XY. The possible evolution
of the W chromosome is discussed.
Acknowledgments
The help of present and former assistants of
the Genetics Laboratory is gratefully acknowl-
edged, in particular Mrs. Pamela MacIntyre and
my wife, Judith, who raised most of the fish of
the more recent collections. The 1963 expedi-
tion to Guatemala was successful and enjoyable
thanks to Mr. Robert Dorion, Guatemala City,
whose enthusiasm, hospitality and knowledge of
the country greatly facilitated the collections.
Senor Jorge Ibarra, Director, Museo Nacional
de Historia Natural, placed the facilities of his
museum graciously at our disposal. The expedi-
tion was supported by funds from the Depart-
ment of Ichthyology, American Museum of
Natural History, and by the New York Zoologi-
cal Society.
Dr. D. E. Rosen, a member of the 1963 ex-
pedition, and Dr. J. W. Atz, the American
Museum of Natural History, provided valuable
discussions and ideas. I also thank Dr. Atz for
his patient and excellent critical review of the
entire manuscript. The investigations were aided
by a grant from the U. S. Public Health Service,
Ca-06665, and by the laboratory facilities of
the American Museum of Natural History.
188
Zoologica: New York Zoological Society
[50: 13
Bibliography
Aida, T.
1936. Sex reversal in Aplocheilus latipes and a
new explanation of sex differentiation.
Genetics, 21 : 136-153.
Anders, A., & F. Anders
1963. Genetisch bedingte XX- und XY- $ $
und YY- $ $ beim wilden Platypoecilus
maculatus aus Mexiko. Z. Vererbungsl.,
94: 1-18.
Atz, J. W.
1959. Morphological and genetic studies on the
pigmentary patterns of xiphophorin fishes
and their hybrids. Ph.D. thesis, on file
New York University.
1962. Effects of hybridization on pigmentation
in fishes of the genus Xiphophorus. Zoolo-
gica, 47: 153-181.
Bellamy, A. W.
1922. Sex-linked inheritance in the teleost,
Platypoecilus maculatus Gunth. (Ab-
stract). Anat. Rec., 24: 419-420.
1928. Bionomic studies on certain teleosts
(PQeciliinae) II. Color pattern inheritance
and sex in Platypoecilus maculatus
(Gunth.). Genetics, 13: 226-232.
1936. Inter-specific hybrids in Platypoecilus:
one species ZZ-WZ; the other XY-XX.
Proc. Nat. Acad. Sci., 22: 531-535.
Bellamy, A. W., & M. L. Queal
1951. Heterosomal inheritance and sex deter-
mination in Platypoecilus maculatus.
Genetics, 36: 93-107.
Berg, O., & M. Gordon
1953. Relationship of atypical pigment cell
growth to gonadal development in hybrid
fishes. In Gordon, Myron (ed.), Pigment
cell growth. New York, Academic Press,
Inc., pp. 43-71.
Breider, H.
1935. Uber Aussenfaktoren, die das Geschlechts-
verhaltnis von Xiphophorus helleri
Heckel kontrollieren sollen. Z. wiss. Zool.,
146: 383-416.
1937. Gen und Genotypus. Nach Untersuch-
ungen an lebendgebarenden Zahnkarpfen.
Der Ziichter, 60: 70-77.
1942. ZW-Mannchen und WW-Weibchen bei
Platypoecilus maculatus. Biol. Zbh, 62:
187-195.
Clark, E., L. R. Aronson & M. Gordon
1954. Mating behavior patterns in two sym-
patric species of xiphophorin fishes: Their
inheritance and significance in sexual iso-
lation. Bull. Am. Mus. Nat. Hist., 103:
135-226.
Darnell, R. M.
1962. Fishes of the Rio Tamesi and related
coastal lagoons in East-Central Mexico.
Publ. Inst. Mar. Sci. Univ. Texas, 8:
299-365.
Dzwillo, M.
1962. Uber kiinstliche Erzeugung funktioneller
Mannchen weiblichen Genotyps bei Lebi-
stes reticulatus. Biol. Zbk, 81: 575-584.
Friedman, B., & M. Gordon
1934. Chromosome numbers in xiphophorin
fishes. Am. Nat., 68: 446-455.
Gordon, H., & M. Gordon
1954. Biometry of several populations of the
platyfish, Xiphophorus maculatus, from
Central America. Zoologica, 39: 37-59.
1957. Maintenance of polymorphisms by poten-
tially injurious genes in eight natural
populations of the platyfish, Xiphophorus
maculatus. J. Genet., 5: 1-44.
Gordon, M.
1927. The genetics of a viviparous top-minnow
Platypoecilus-, the inheritance of two kinds
of melanophores. Genetics, 12: 253-283.
1937a. Genetics of Platypoecilus. III. Inheri-
tance of sex and crossing over of the sex
chromosomes in the platyfish. Genetics,
22: 376-392.
1937b. The production of spontaneous melanotic
neoplasms in fishes by selective matings.
Am. J. Cancer, 30: 362-375.
1946. Interchanging genetic mechanisms for sex
determination in fishes under domestica-
tion. J. Hered., 37: 307-320.
1947. Genetics of Platypoecilus maculatus. IV.
The sex determining mechanism in two
wild populations of the Mexican platy-
fish. Genetics, 32: 8-17.
1948. Effects of five primary genes on the site
of melanomas in fishes and the influence
of two color genes on their pigmentation.
Spec. Pub. N. Y. Acad. Science, 4: 216-
268.
1950a. Genetics and speciation in fishes. Am.
Philo. Soc. Year Book, 1949: 158-159.
1950b. Fishes as laboratory animals. In “The
Care and Breeding of Laboratory Ani-
mals.” E. Farris, Editor, lohn Wiley &
Sons, New York, pp. 345-449.
1 95 1 a. Genetics of Platypoecilus maculatus. V.
Heterogametic sex-determining mecha-
nism in females of a domesticated stock
originally from British Honduras. Zoolo-
gica, 36: 127-134.
1951b. The variable expressivity of a pigment
cell gene from zero effect to melanotic
tumor induction. Cancer Research, 11:
676-686.
1952. Sex determination in Xiphophorus (Platy-
poecilus) maculatus. III. Differentiation
of gonads in platyfish from broods hav-
ing a sex ratio of three females to one
male. Zoologica, 37: 91-100.
1954. Two opposing sex-determining mecha-
nisms, one XX-XY, the other WY-YY,
in different natural populations of the
platyfish, Xiphophorus maculatus. Caryo-
logia 6, suppl., 960-964.
1965]
Kallman: Genetics and Geography of Sex Determination in Xiphophorus maculatus
189
1957. Physiological Genetics of Fishes. In “The
Physiology of Fishes,” Academic Press,
vol. 2: 431-501.
Gordon, M., & G. M. Smith
1938. The production of a melanotic neoplastic
disease in fishes by selective matings. IV.
Genetics of geographical species hybrids.
Am. J. Cancer, 34: 543-565.
Gordon, M., & D. E. Rosen
1951. Genetics of species differences in the
morphology of the male genitalia of
xiphophorin fishes. Bull. Am. Mus. Nat.
Hist., 95: 409-464.
Haskins, C. P., E. F. Haskins, J. J. A. McLaughlin
& R. E. Hewitt
1961. Polymorphism and population structure
in Lebistes reticulatus. In: Vertebrate
Speciation. University of Texas Press:
320-395.
Hubbs, C.
1964. Interactions between a bisexual fish spe-
cies and its gynogenetic sexual parasite.
Bull. Texas Mem. Mus., 8: 1-72.
Hubbs, C. L., & L. C. Hubbs
1932. Apparent parthenogenesis in nature, in a
form of fish of hybrid origin. Science,
76: 628-630.
Humphrey, R. R.
1945. Sex determination in ambystomid sala-
manders: a study of the progeny of fe-
males experimentally converted into
males. Am. J. Anat., 76: 33-66.
1948. Reversal of sex in females of genotype
WW in the Axolotl ( Siredon or Amby-
stoma mexicanum) and its bearing upon
the role of the Z chromosomes in the
development of the testis. J. Exp. Zool.,
109: 171-185.
Kallman, K. D.
1962. Gynogenesis in the teleost, Mollienesia
formosa (Girard), with a discussion of
the detection of parthenogenesis in ver-
tebrates by tissue transplantation. J.
Genet., 58: 7-24.
1964. Genetics of tissue transplantation in iso-
lated platyfish populations. Copeia (1964):
513-522.
1965. Sex determination in the teleost Xipho-
phorus milleri. Am. Zool., 5: 246-247.
Kosswig, C.
1928. Uber Kreuzungen zwischen den Teleos-
tiern Xiphophorus helleri und Platypoe-
cilus maculatus. Z. indukt. Abstamm.- u.
Vererb.-Lehre, 47: 150-158.
1929. Zur Frage der Geschwulstbildungen bei
Gattungsbastarden der Zahnkarpfen Xi-
phophorus und Platypoecilus. Z. indukt. -
u. Vererb.-Lehre, 52: 114-120.
1931. Die geschlechtliche Differenzierung bei
den Bastarden von Xiphophorus helleri
und Platypoecilus maculatus und deren
Nachkommen. Z. indukt. Abstamm.- u.
Vererb.-Lehre, 57: 226-305.
1934. Farbfaktoren und Geschlechtsbestimmung
(nach Untersuchungen an Zahnkarpfen).
Der Ziichter, 6: 40-47.
1935. Genotypische und phanotypische Ge-
schlechtsbestimmung bei Zahnkarpfen. V.
Ein X (Z)-Chromosom als Y-Chromosom
in fremdem Erbgut. Roux’ Archiv. Ent-
wicklungs. Organ., 133: 118-139.
1936. Homogametische ZZ- und fFlF-Weibchen
entstehen nach Artkreuzung mit dem im
weiblichen Geschlecht heterogametischen
Platypoecilus maculatus. Biol. Zbl., 56:
409-414.
1937. Genotypische und phanotypische Ge-
schlechtsbestimmung bei Zahnkarpfen.
VII. (Kreuzungen mit Platypoecilus xi-
phidium). Roux’ Archiv. Entwicklungs.
Organ., 136: 491-528.
1938. Uber einen neuen Farbcharakter des
Platypoecilus maculatus. Istanbul Univ.
Fen. Fak. Mecm., B 3: 1-8.
1939. Die Geschlechtsbestimmung in Kreuz-
ungen zwischen Xiphophorus und Platy-
poecilus. Istanbul Univ. Fen. Fak. Mecm.,
B 4: 1-54.
1959. Beitrage zur genetischen Analyse xipho-
riner Zahnkarpfen. Biol. Zbl., 78: 711-718.
1964. Polygenic sex determination. Experientia,
20: 1-10.
Kosswig, C., & M. Oktay
1955. Die Geschlechtsbestimmung bei den Xi-
phophorini (Neue Tatsachen und neue
Deutungen). Istanbul Univ. Fen Fak.
Hidrob., B 2: 133-156.
Krumholz, L. A.
1963. Relationships between fertility, sex ratio,
and exposure to predation in populations
of the mosquito fish Gambusia manni.
Int. Rev. ges. Hydrobiol., 48: 201-256.
MacIntyre, P. A.
1961. Spontaneous sex reversals of genotypic
males in the platyfish ( Xiphophorus
maculatus) . Genetics, 46: 575-580.
Mikamo, K., & E. Witschi
1963. Functional sex reversal in genetic females
of Xenopus laevis, induced by implanted
testes. Genetics, 48: 1411-1421.
Miller, R. R.
1960. Four new species of viviparous fishes,
genus Poeciliopsis, from northwestern
Mexico. Occ. Papers Mus. Zool. Univ.
Mich., 619: 1-11.
Miller, R. R., & R. J. Schultz
1959. All-female strains of the teleost fishes of
the genus Poeciliopsis. Science, 130:
1656-1657.
Oktay, M.
1959a. Uber Ausnahmemaennchen bei Platy-
poecilus maculatus und eine neue Sippe
mit XX- Maennchen und XX-Weibchen.
Istanbul Univ. Fen Fak. Mecm., B24:
75-91.
190
Zoologica: New York Zoological Society
[50: 13: 1965]
1962. Die Rolle artfremder Gonosomen bei der
Geschlechtsbestimmung von Bastarden
mit Platypoecilus maculatus. Istanbul
Univ. Fen Fak. Hidrob., B 6: 1-13.
OZTAN, N.
1960. The effects of gonadotropic and steroid
hormones on the gonads of sterile hybrid
fishes. Istanbul Univ. Fen Fak. Mecm.,
B 25: 27-56.
1963. The hypothalamic neurosecretory system
of a poeciliid fish, Platypoecilus macu-
latus and its sterile hybrid backcross with
Xiphophorus helleri. Gen. Comp. En-
docr., 3: 1-14.
Peters, G.
1964. Vergleichende Untersuchungen an drei
Subspecies von Xiphophorus helleri
Heckel (Pisces). Z. zool. Syst. Evolutions-
forschung, 2: 185-271.
Rosen, D. E.
1960. Middle- American poeciliid fishes of the
genus Xiphophorus. Bull. Florida State
Mus., 5: 57-242.
Rosen, D. E., & R. M. Bailey
1963. The poeciliid fishes (Cyprinodontiformes),
their structure, zoogeography, and sys-
tematics. Bull. Am. Mus. Nat. Hist., 126:
1-176.
Rust, W.
1939. Miinnliche und weibliche Heterogametie
bei Platypoecilus variatus. Z. indukt.
Abstamm.- u. Vererb.-Lehre, 77: 172-176.
Schreibman, M. P., & H. A. Charipper
1962. The occurrence of pituitary cysts in a
particular strain of platyfish ( Xiphopho-
rus maculatus) . Am. Zool., 2: 556.
Schroder, J. H.
1964. Genetische Untersuchungen an domesti-
zierten Stammen der Gattung Mollienesia
(Poeciliidae). Zoologische Beitrage, 10:
369-463.
Schultz, R. J.
1961. Reproductive mechanism of unisexual and
bisexual strains of the viviparous fish
Poeciliopsis. Evolution, 15: 302-325.
Sengun, A.
1941. Ein Beitrag zur Geschlechtsbestimmung
bei Platypoecilus maculatus und Xipho-
phorus helleri. Istanbul Univ. Fen Fak.
Mecm., B 4: 33-48.
1950. Beitrage zur Kenntnis der erblichen Be-
dingtheit von Formunterschieden der
Gonopodien lebendgebarender Zahnkarp-
fen. Istanbul Univ. Fen Fak. Mecm., B
15: 110-133.
Tavolga, W. N.
1949. Embryonic development of the platyfish
( Platypoecilus ), the swordtail ( Xipho-
phorus) and their hybrids. Bull. Am. Mus.
Nat. Hist., 94: 167-229.
White, M. J. D.
1954. Animal Cytology and Evolution, 2nd ed.
Cambridge University Press, Cambridge,
England.
Winge, O.
1930. On the occurrence of XX males in
Lebistes, with some remarks on Aida’s so-
called “nondisjunctional” males in Aplo-
cheilus. J. Genet., 23: 69-76.
Winge, O.
1934. The experimental alteration of sex chro-
mosomes into autosomes and vice versa,
as illustrated by Lebistes. Compt.-rend.
Lab. Carlsberg, Ser. physiol., 21: 1-49.
Winge, O., & E. Ditlevsen
1948. Colour inheritance and sex determination
in Lebistes. Compt.-rend. Lab. Carlsberg,
Ser. physiol., 24: 227-248.
Yamamoto, T.
1953. Artificially induced sex-reversals in geno-
typic males of the medaka ( Oryzias
latipes). I. exp. Zool., 123: 571-594.
1955. Progeny of artificially induced sex-
reversals of male genotype (XY) in the
medaka (Oryzias latipes) with special
reference to YY-male. Genetics, 40: 406-
419.
1958. Artificial induction of functional sex re-
versal in genotypic females of the medaka
(Oryzias latipes). I. exp. Zool., 137: 227-
264.’
1959a. A further study on induction of func-
tional sex reversal in genotypic males of
the medaka (Oryzias latipes) and proge-
nies of sex reversals. Genetics, 44: 739-
757.
1959b. The effects of estrone dosage level upon
the percentage of sex reversals in genetic
male (XY) of the medaka (Oryzias
latipes). J. exp. Zool., 141: 133-154.
1962. Hormonic factors affecting gonadal sex
differentiation in fish. Gen. Comp. En-
docr., (Suppl. ) , 1: 341-345.
1963. Induction of reversal in sex differentiation
of YY zygotes in the medaka, Oryzias
latipes. Genetics, 48: 293-306.
1964. The problem of viability of YY zygotes
in the medaka, Oryzias latipes. Genetics,
50: 45-58.
Zander, C. D.
1962. Untersuchungen iiber einen arttrennenden
Mechanismus bei lebendgebarenden Zahn-
karpfen aus der Tribus Xiphophorini.
Mitt. Hamburg Zool. Mus. Inst., 60:
205-264.
1964. Physiologische und genetische Unter-
suchungen zur Systematik xiphophoriner
Zahnkarpfen. Mitt. Hamburg Zool. Mus.
Inst. (Kosswig-Festschrift), 62: 33-348.
1965. Die Geschlechtsbestimmung bei Xipho-
phorus montezumae cortezi (Rosen)
(Pisces). Z. Vererbungsl., 96: 128-141.
SU‘S 73
ZOOLOGICA
SCIENTIFIC CONTRIBUTIONS OF THE
NEW YORK ZOOLOGICAL SOCIETY
VOLUME 50 • ISSUE 4 • WINTER, 1965
PUBLISHED BY THE SOCIETY
The ZOOLOGICAL PARK, New York
Contents
PAGE
14. Speciation in Heliconius (Lep., Nymphalidae) : Morphology and Geo-
graphic Distribution. By Michael G. Emsley. Maps 1-30; Text-figures
1-173 191
15. A Technique for the Recording of Bioelectric Potentials from Free-flying
Insects (Lepidoptera: Heliconius erato ). By S. L Swihart & J. G. Baust.
Plates I & II .255
Index to Volume 50 259
Zoologica is published quarterly by the New York Zoological Society at the New York
Zoological Park, Bronx Park, Bronx, N. Y. 10460, and manuscripts, subscriptions, orders for back
issues and changes of address should be sent to that address. Subscription rates: $6.00 per year;
single numbers, $1.50, unless otherwise stated in the Society’s catalog of publications. Second-class
postage paid at Bronx, N. Y.
Published December 31, 1965
14
Speciation in Heliconius (Lep., Nymphalidae) :
Morphology and Geographic Distribution1'
Michael G. Emsley
William Beebe Tropical Research Station,
New York Zoological Society,
Arima Valley, Trinidad, West Indies
(Maps 1-30; Text-figures 1-173)
[This paper is a contribution from the William
Beebe Tropical Research Station of the New York
Zoological Society at Simla, Arima Valley, Trinidad,
West Indies. The Station was founded in 1950 by
the Zoological Society’s Department of Tropical Re-
search under the late Dr. Beebe’s direction. It com-
prises 250 acres in the middle of the Northern Range,
which includes large stretches of government forest
reserves. The altitude of the research area is 500 to
1,800 feet, with an annual rainfall of more than 100
inches.
[For further ecological details of meteorology and
biotic zones see “Introduction to the Ecology of the
Arima Valley, Trinidad, B. W. I.” by William Beebe,
Zoologica, 1952, Vol. 37, No. 13, pp. 157-184],
Contents Page
I. Introduction 192
II. Acknowledgments, Materials and
Methods 192
III. Constitution and Geographic Distribution
of Heliconius 193
Subgenus Eueides 195
The alipherus Group 195
1. Heliconius alipherus. . . . (Map 1) . . . . 195
The edias Group 196
2. Heliconius edias (Map 2) . . . . 196
The vibilius Group 198
3. Heliconius vibilius (Map 3) . . . . 198
4. H. pavanus (Map 4).... 198
5. H. lineatus (Map 4) . . . . 199
6. H. eanes (Map 4) . . . . 199
7. H. isabellae (Map 5) . . . . 199
Contribution No. 1070, Department of Tropical Re-
search, New York Zoological Society.
2This study has been supported by the National Science
Foundation (G-21071 and GB-2331).
The lybiits Group
200
8. Heliconius lybius . . . .
. . (Map 6) . . . .
200
9. H. tales
..(Map 7)....
201
Subgenus Heliconius . . .
201
The natteri Group
201
10. Heliconius natteri . . .
. .(Map 8)
201
The hierax Group
202
1 1. Heliconius hierax . . . .
. .(Map 2). . . .
202
The godmani Group
202
12. Heliconius godmani . .
. .(Map 8) . . . .
202
13. H. aoede
. .(Map 9). . . .
202
14. H. metharme
. . (Map 8) . . . .
203
The wallacei Group
203
15. Heliconius wallacei . .
.(Map 10)
203
16. H. burneyi
.(Map 11)
203
17. H. egerius
.(Map 12)
204
The doris Group
204
18. Heliconius doris . . . .
.(Map 13)
204
The hecubus Group
205
19. Heliconius hecubus . .
. (Map 14) . . . .
205
20. H. xanthocles
. (Map 14) . . . .
206
The numatus Group
206
21. Heliconius numatus . .
.(Map 15)....
207
22. H. aristionus
.(Map 16)
208
23. H. atthis
. (Map 16) . . . .
208
24. H. ethillus
. (Map 17) . . . .
209
25. H. hecale
. (Map 21) ...
210
26. H. elevatus
. (Map 19) . . . .
210
27. H. melpomene
.(Map 18)
211
28. H. cydno
.(Map 19)
212
29. H. pachinus
. (Map 16). . . .
213
The hecalasius Group . . .
213
30. Heliconius hecalasius .
.(Map 20)
214
31. H . longarenus
. (Map 20) ... .
214
32. H. hermathenae
. (Map 21 )
214
33. H. himerus
. (Map 20) ... .
215
34. H. erato
.(Map 23)
215
191
192
Zoologica: New York Zoological Society
[50: 14
35 . H.telesiphe (Map 12) . . . . 215
36. H. clysonymus (Map 22) .... 216
37 .H.hortense (Map 22).... 216
The charitonius Group 216
38 . H. charitonius (Map 21).... 217
39 . H.ricini (Map 22) 217
40. H. demeter (Map 2) . . . . 217
41 .H.sarae (Map 24).... 217
42. H. leucadius (Map 25) .... 218
43. H. hygianus (Map 11).... 218
44. H. antiochus (Map 26) ... . 219
45. //. saplio (Map 25).... 219
46. H. hewitsoni (Map 10) . . . . 220
Maps 220
Taxonomic References 233
IV. Summary of Systematic Presentation . . . 235
V. Evolutionary Discussion 244
VI. Summary 254
VII. References 254
I. Introduction
BATES’ views on mimicry are now well
known but it is not so widely appreciated
that it was his observations on members of
the genus Heliconius in the Amazon basin that
really stimulated his curiosity. The diversity of
this neotropical genus, both in speciation and
intraspecific multiformity, has challenged taxon-
omists throughout the hundred years or so that
material has been accumulated, but the principal
difficulties that have faced museum workers are
still pertinent. These include the shortage of rea-
sonably long series of specimens from reliable
localities and the relatively small number of lo-
calities from which collections have been ob-
tained. Moreover, much of the older material is
accompanied only by vague or erroneous locality
data, but this is a point which has already been
elaborated in the detailed study of Heliconius
melpomene and H. erato (Emsley, 1964).
The taxonomic works of importance concern-
ing Heliconius are those of Stichel & Riffarth
(1905) and Seitz (1913), who used only macro-
scopic alary characters, and the more rational
approach of Eltringham (1916), who employed
also male genital characters in a determined ef-
fort to reduce the total number of recognized
species. With the exception of Michener (1942),
who introduced venation in a short revision of
the subfamily, the only use of other morpho-
logical features is by Emsley (1963), who based
a systematic arrangement of the subfamily on the
shape and distribution of the androconia, the
presence and shape of the signa on the bursa
copulatrix, the shape of the female abdominal
processes, the breadth of the duct to the sperma-
thecal diverticulum, the proportionate lengths of
the two components of the bifid pretarsal paro-
nychia together with the structure of the male
genital valves. These characters have also been
found to be of relevance to the systematics of
Heliconius and are the principal structures upon
which this reassessment is based.
II. Acknowledgments, Materials
and Methods
The materials upon which this study has been
made are the collections of the British Museum
(Natural History) at London and Tring, those
of the Hope Department of Entomology at
Oxford and the American Museum of Natural
History in New York, and a portion of the col-
lection of the Museum of Natural History in
Paris. The author is indebted to the trustees of
these institutions for study facilities and loan of
specimens and particularly to Mr. Howarth and
Mr. Tite of the British Museum at London and
Tring respectively for their willing cooperation.
Thanks are offered to Dr. E. W. Schmidt-
Mumm3 for a substantial gift of Heliconius
specimens from his most useful Colombian col-
lection and for his advice and assistance while
the author was traveling in Colombia. Malcolm
Barcant4 must also be included in the acknowl-
edgments for his assistance on field trips and
for access to his comprehensive collection of
Trinidad butterflies. The author is most grateful
to Jocelyn Crane, Director of the New York
Zoological Society’s Department of Tropical Re-
search, for the first instilling interest in this group
and for her continued support, to Julie Emsley
for her diligent assistance in the museums and
for the drawings accompanying this text and to
the National Science Foundation for the award
of a grant (G-21071) which financed this work.
Lastly, mention must be made of F. Martin
Brown5 who has kindly advised on this paper,
which concerns a group in which he has been
interested and most knowledgeable for many
years.
The relevant parts of the dried museum mate-
rial were removed, macerated in 5% potassium
hydroxide and examined in glycerine. Structures
dissected off museum specimens were preserved
in glycerine in minute vials which were then
attached by their stoppers to the pins of the
specimens. No permanent slide preparations
were made. The distribution of androconia was
3Dr. E. W. Schmidt-Mumm, Optometra, Calle 12, No.
7-19, Bogota.
■‘Malcolm Barcant, Lot 19, San Diego Park, Diego
Martin, Port-of-Spain, Trinidad, W. Indies.
5Martin Brown, Fountain Valley School, Colorado
Springs, Colorado 80907, U. S. A.
1965]
Emsley: Speciation in Heliconius
193
Text-figs. 1 & 2. Fore (1) and hind (2) wings of typical Heliconius to illustrate venational nomencla-
ture. C— costa; Sc— subcosta; R! to R5— first to fifth branches of the radius; Rs— radial sector; Ml to M3
—first to third branches of the media; Cu— cubitus; Cula and Cul b— branches of first cubitus; 1A and
2A— first and second anal veins; H— humeral branch of subcosta; M-Cu— medio-cubitus crossvein.
determined by microscopic examination of the
wings while they were immersed in 90% alcohol.
The reluctance of earlier lepidopterists to “dam-
age” their specimens by such dissection has re-
tarded the growth of our understanding of the
systematics of Heliconius and probably of many
other papilionoid groups.
In principal this paper is to be regarded as a
study in evolutionary taxonomy and no special
effort has been made to check the nomenclatorial
precedence of the names used, or to become too
deeply involved in the detailed variations within
the species. The prime objective has been to
define the geographic and polychromatic forms
within species and to relate them to each other
in such a way that their evolutionary history may
be postulated.
III. Constitution and Geographic
Distribution of Heliconius
Though the names used here are those adopted
by Neustetter (1929), it has been possible to
reduce the number of recognized species from
107 to 46. No new names are being proposed
to associate the species as there is already a con-
fusing number of infrageneric group names. In-
stead, species-groups will be suggested and the
species held to be the most primitive in each
association will be selected as the titular species
of the group.
In order to facilitate the description of alary
characters, the venational terminology is illus-
trated in Text-figs. 1 and 2, and the appearance
of the major and minor elements of the color
pattern can be identified by reference to Text-
figs. 3-12 (and see Emsley, 1964, color plate I,
figs. 1-8).
The nomenclatorial authorities are quoted: —
“Author year: page” and the strictly taxonomic
references are placed near the end of Section III
so they do not mask the more interesting general
references at the end of the paper.
Heliconiinae Swainson 1827: 187
Definition: Nymphalid Papilionoidea with the
humeral branch of the subcosta at the anterior
base of the hindwing recurrent and unforked
(Text-fig. 2); the presence in males of andro-
conia on some of the fore and/or hindwing
veins and with a pair of lateral capitate proc-
esses developed from the posterior margin of
the eighth abdominal segment of females.
Included genera and species are:
Philaethria Billberg 1820:77
194
Zoologica: New York Zoological Society
[50: 14
Text-figs. 3-10. The elements of the color pattern of Heliconius. 3, ventral view of right forewing to
show costal spot (csp) and lines over radius and cubitus; 4, similar view of hindwing to show costal
streak (cst), basal spots (bsp) and paired intervenal white streaks; 5, dorsal view of right forewing to show
red base (= dennis); 6, dorsal view of right hindwing to show ray in H. erato; 1 , ditto in H. doris eratonius;
8, ditto in H. melpomene timaretus; 9, ditto in doris doris; 1 0, ditto in H . tales. About twice natural size.
P. dido (Clerk 1764, pi. 30)
Dryadula Michener 1942:4
D. phaetusa (Linnaeus 1758:478)
Agraulis Boisduval & Le Conte 1836: 142
A. vanillae (Linnaeus 1758:482)
Dione Hiibner 1818:31
D. juno (Cramer 1779:38)
D. moneta Hiibner 1825, pi. 20.
D. glycera (C. & R. Felder 1861 : 102)
Podotricha Michener 1942:3
P. euchroia (Doubleday 1847:149)
P. telesiphe (Hewitson 1867b: 564)
Colaenis Hiibner 1819:32 (see footnote 6)
i;Since the survey of the subfamily (Emsley, 1963), it
has been noticed that the Commission on Zoological
Nomenclature rejected the generic name Dryas Hiibner
1806 (opinion 278 on January 22, 1954, published
October 1, 1954) on the grounds that it was included
in a work which is inacceptable for nomenclatorial pur-
poses (in tentamen).
1965]
Emsley: Speciation in Heliconius
195
Text-figs. 11 & 12. Diagrammatic representations of the positions of the forewing band (11) and hind-
wing bar (12) which are of common occurrence in Heliconius.
C. iulia (Fabricius 1775:509)
Heliconius Kluk 1802:82
46 species, discussed below.
Heliconius Kluk 1802:82 (see footnote 7)
Genotype: Papilio charitonia Linnaeus 1767 :757
Designated by Hemming, 1933:223
Definition : Heliconiinae with the discal cell of
the hindwing closed by cross-vein M2-M3 (Text-
fig. 2).
Subgenus Eueides Hiibner 1816:11
Subgenotype: Nereis dianasa Hiibner 1816:11
Definition: Heliconius with a narrow duct lead-
ing from the spermathecal diverticulum (Text-
fig. 18) and four-segmented tarsi on the fe-
male foreleg (Text-figs. 14, 15). These char-
acters are reinforced in most species by the
acute angle through which the signa of the
bursa copulatrix are curved and their tend-
ency to asymmetry (Text-figs. 24, 25), and
the exclusion of the androconia from the
membrane around the hindwing veins Sc +
R1 or Rs (Text-fig. 29).
THE ALIPHERUS GROUP
Group characters are the presence of andro-
conia on hindwing veins Sc + Rl, Rs, Ml, M2,
M3, Cu la and Cu lb (Text-fig. 75), but only
on forewing vein 1A; the strongly acute-angled
and asymmetrical signa (Text-figs. 24, 25); the
almost straight female processes (Text-fig. 161 ) ;
and the coarsely spinose and unequal parony-
chial processes (Text-fig. 23).
"Accepted as a valid generic name by the Commission
on Zoological Nomenclature (opinion 382 of April 15,
1955, published January 24, 1956). Paclt, 1955: 431,
gives evidence that Kluk’s publication date was 1780.
1. Heliconius alipherus (Godart 1819:246)
Map 1 : Text-figs. 15, 23, 24, 25, 32, 75 and 161
H. alipherus is the most widely distributed
and stable species of Heliconius , extending from
Mexico to upper Paraguay. It occurs on Trinidad
and Tobago (and possibly Grenada) where as
elsewhere within its range it is common. It is a
small orange butterfly (wingspan $ 56 mm., $
63 mm.) with a dorsal brown border which
extends proximally as a series of weakly devel-
oped venal and intervenal spikes; there is also
a dark line on the forewing along the discal
border of R which curves posteriorly across M3,
and another along 1A. The dark pattern of fe-
males is less strongly developed and the ground
color is a little lighter. Ventrally the ground
color has a pinkish tinge, the veins are brown
and there are ochreous patches at the apex of
the discal cell and at the distal extremity of the
forewing. There are no red basal spots (Text-
fig. 4) but the forewing costal spot (Text-fig. 3)
and hindwing costal streak (Text-fig. 4) are
differentiated in a darker orange.
The only appreciable geographic variation is
a cline of increase in the intensity and extent of
the dark markings and richness of the orange
ground color from west of Colombia into South
America east of the Andes. The pale and less
maculate western and northern forms have been
called cillenulus Seitz 1913:399 when the ground
color is buff and gracilis Stichel 1903:23 when
it is orange; they match the pale sympatric
Colaenis iulia moderata Stichel 1907:12 which
similarly occurs in Central America, and Col-
ombia and Ecuador west of the Andes. The
factor which contributes most to the pale appear-
ance is the reduction, sometimes to total absence,
of the dark forewing lines across M3 and along
1A.
196
Zoologica: New York Zoological Society
[50: 14
Text-figs. 13-15. External view of right tarsi of
female foreleg of 13, H. (Heliconius) melpomene ;
14, H. (Eueides) isabellae; 15, H. (Eueides) ali-
pherus.
Text-figs. 16-18. Lateral view of spermatheca, with
diverticulum (sp. div.), of 16, typical member of
subgenus Heliconius; 1 7, godmani group of sub-
genus Heliconius; 1 8, typical member of subgenus
Eueides.
Text-figs. 19-23. Ventral view of meso or meta-
pretarsus of 1 9, H. melpomene; 20, H. wallacei;
21, H. erato; 22, H. isabellae; 23, H. alipherus.
Specific Characters: In addition to the group
characters, there is the shape of the male genital
valves (Text-fig. 32) and the absence of a spine
at the apex of the female protarsus (Text-fig.
15).
THE EDI AS GROUP
Group features are the presence of androconia
on many forewing veins (Text-fig. 98), on hind-
wing vein Sc + R1 and extensively on Rs (Text-
fig. 76); the strongly curved female processes
(Text-fig. 170); and the rotund signa (Text-fig.
149).
2. Heliconius edias Hewitson 1861:155
Map 2; Text-figs. 34, 76, 98, 149, 170
This species, though broadly restricted to the
northern Andes, is differentiated into the west-
ern eurysaces Hewitson 1864:248, northern
vulgiformis Butler & Druce 1872:102, and cen-
tral edias and umbratilis Rober 1927:403. The
wingspan approximates to 72 mm.
Though occurring in Costa Rica and perhaps
as far north as Mexico, vulgiformis is the char-
acteristic form from Panama and has three
cream forewing spots in position A, one spot in
position B and an interrupted band in position
C (Text-fig. 11); there is no line over the cubitus
but the post 1A margin is orange, and the hind-
wing has a broad orange bar in coalesced posi-
tions I + II + III + IV (Text-fig. 12). The fore-
wing costal spot is orange and there may be a
yellow spot enclosed by the recurrent branch of
the hindwing subcosta (Text-fig. 4). There is a
submarginal (position V) row of paired white
spots on the ventral surface of the hindwing. Fe-
males are only slightly more pale than males.
The appearance of edias, from around the
spurs of the Andes in northern Colombia, is
similar to that of vulgiformis but the forewing
band spots are larger and more orange, there is
an orange line over the stem of the cubitus, and
the peripheral black invades the distal hindwing
vein endings. Females are much more pale than
males.
To the west, on the Pacific slopes of Ecuador,
the pale and diaphanous form eurysaces is quite
distinct. The markings are vague with the pale
orange line over the forewing cubitus broad and
contiguous with the inner forewing band in
position A, and the outer band in position C is
very faint. The orange forewing costal spot is
barely detectable. Females are even more pale
than the males, which are not unlike the most
pale female edias.
The status of proculus Doubleday 1848:146
and luminosus Stichel 1903:16 from the moun-
1965]
Emsley: Speciation in Heliconius
197
Text-figs. 24-28. Right lateral views of bursa copulatrices to show shape and orientation of signa. 24,
H. alipherus; 25, right side of left signum of H. alipherus to demonstrate asymmetry; 26, H. melpomene
or cydno or pachinus or ethillus or numatus or hecale or aristionus; 27, H. doris; 28, H. erato and other
non-signate species.
tains of Venezuela and eastern Colombia respec-
tively is still uncertain, for they differ from H.
edias in not having androconia on any forewing
veins other that 1A, but the hindwing distribu-
tion is similar and more extensive than in H.
vibilius. The female abdominal processes are
strongly curved as in H. edias (Text. -fig. 170),
and the male genital valves are of the long-
processed H. edias type (Text-fig. 34), as are
the signa (Text-fig. 149). The forewing band is
only represented by a compact cream band in
position A, which is a component of both H.
edias and H. vibilius, and the forewing costal
spot, which is orange in H. edias and yellow in
H. vibilius, is orange and yellow in proculus.
Temporarily, proculus is assigned to H. edias
and is considered an isolated form in which the
forewing androconia have been lost from all
veins except 1A, but the position is unsatisfac-
tory.
The form ascidius Schaus 1921:108 has not
been seen.
Specific Characters: The presence of an-
droconia on many forewing veins (Text-fig. 98)
together with the shape of the male genital valves
(Text. -fig. 34). The forms luminosus and pro-
Text-Figs. 29-31. Dorsal views of left hindwings of male Heliconius to show the androconial distribution
in 29, H. ( Eueides ) vibilius lampeto; 30, H. ( Heliconius ) sapho congener; 31, H. ( Heliconius ) pachinus.
198
Zoologica: New York Zoological Society
[50: 14
cuius have forewing androconia only on 1A.
Note that the genitalia alone are hard to dis-
tinguish from some members of the vibilius
group.
THE VIBILIUS GROUP
Group features are the hindwing androconia
only on veins Sc + R1 and Rs (Text-figs. 29,
76); the absence of androconia on all forewing
veins, including 1A; the female abdominal pro-
cesses which are similar to those of H. alipherus
(Text-fig. 161); the strongly arched slightly
asymmetrical signa (Text-fig. 150); and the de-
velopment of a recurved hook at the dorsal base
of the ventral component of the male genital
valves (Text-figs. 33, 35, 36, 37) (a character
which is shared with H. edias ) .
3. Heliconius vibilius (Godart 1819:245)
Map 3: Text-figs. 29, 33, 76, 150, 161
This is a wide-ranging species which extends
from southern Brazil to eastern Colombia and
from Panama to Guatemala and over which
there is still some taxonomic uncertainty. The
basic pattern is a dark brown ground color on
which the forewing carries a pair of cream or
orange bands in positions A and C, an orange
line over the cubitus and an orange posterior
border; on the hindwing there is an orange bar
in coalesced positions I + II + III which has the
veins differentiated in black. Ventrally the dorsal
pattern is reproduced but it is more pale and
there is a yellow spot contained by the recurrent
branch of the hindwing subcosta, a yellow
forewing costal spot and a single row of paired
intervenal white spots around the posterior mar-
gin of the hindwing. Females tend to be less
heavily or richly marked than males but are
similar in size, with a wingspan of approximately
72 mm.
In Central America the form vialis Stichel
1903:20 is known from southern Mexico to the
borders of Colombia but south of Costa Rica it
seems progressively replaced by Heliconius edias
vulgiformis. Very few specimens that can clearly
be assigned to H. vibilius are known from the
central Colombian or Ecuadorian Andean val-
leys, from Venezuela or the Guianas, but from
the Lower, Middle and Upper Amazon there is
the stable form vibilius which is distinguishable
from vialis only by the richer orange of the fore-
wing bands, the more extensive orange over the
forewing cubitus and by the vagueness of the
posterior margin of the hindwing orange bar.
In the upper tributaries of the Amazon the
pattern becomes more richly orange and the dis-
tal forewing band is absent ( unifasciatus Butler
1873:169).
In the valleys of the eastern Colombian,
Ecuadorian and Peruvian Andes above 650
meters there is a high degree of variability but in
general the orange markings are greatly extended
so they may appear to form the ground color ex-
cept in the position of hindwing bar III. Named
forms included in this complex are lampeto
Bates 1862:563, fulginosus Stichel 1903:12,
amoenus Stichel 1903:13, carbo Stichel 1903:
13, apicalis Rdber 1927:402 and acacates
Hewitson 1869b: 22. An especially pale form
from this area has been named pallidus Riffarth
1907:513. To the south in eastern and southern
Brazil the distal band is retained though the
color is still rich orange. Especially pale forms
occur here too and have been named pollens
Stitchel 1903:19.
The little known form copiosus Stichel
1906:57, which looks as if it should come from
eastern Ecuador but carries the locality of
British Guiana, is unlikely to be a series of label-
ling errors and may exemplify the extreme var-
iability of this species, or it may be an interspecific
hybrid between H. vibilius and H. isabellae.
Only a female has been examined.
In the A.M.N.H. there is a single female speci-
men recorded from La Lechera, Rio Opon, north
of Tunja, Boyaca, Colombia, which has typical
vibilius morphology and ventral alary color
pattern but which is dorsally similar to H. lybius
olympius. There is a similar specimen in the
B.M. from La Chima, which is in western
Ecuador. Both localities have aberrent material
in other species, so further specimens must be ob-
tained before the distribution can be confirmed.
Specific Characters: The shape of the male
genital valves (Text-fig. 33) together with the
absence of androconia from all the forewing
veins including 1A, and the extensive distribu-
tion of androconia over hindwing Rs (Text-fig.
76).
4. Heliconius pavanus Menetries 1857:116
Map 4: Text-figs. 33, 76, 148, 161
This species is known from a small number
of specimens from eastern and southern Brazil.
It is in appearance very like H. vibilius vibilius,
with which it is partially sympatric, but it differs
in that the hindwing has black intervenal spikes
on both surfaces and the stems of hindwing
veins Ml and M2 are retained and differentiated
in black; the peripheral light spots on the hind-
wing are silver and in two sub-equally developed
rows, the proximal of which are arranged in
pairs so they look like blocks leaning against
each other. The characters at the wingbase are
as in H. vibilius. Females have the light mark-
ings a pale straw color whereas the males are
1965]
Emsley: Speciation in Heliconius
199
orange, but the sexes are approximately similar
in size (wingspan 68-72 mm.)
Specific Characters: The signa of the fe-
male bursa copulatrix are reduced to short nar-
row bars with the deflection only just visible at
the posterior extremity (Text-fig. 148), and the
female foretarsi are similar to those of H. ali-
pherus in that they lack a terminal spine (Text-
fig. 15). The other characters including the
shape of the male genital valves (Text-fig. 33)
and androconia distribution are as in H. vibilius
(Text-fig. 76).
5. Heliconius lineatus Salvin & Godman
1868:145
Map 4: Text-figs. 35, 77, 150
This species is very similar in appearance to
H. alipherus but the dorsal and ventral ground
colors are a richer orange and the dark markings
are more extensive and more black. Ventrally
there is a round yellow spot enclosed by the
recurrent humeral branch of the subcosta and
an elongate yellow spot in the angle between
Sc + R1 and Rs. The forewing costal spot can
barely be differentiated from the orange ground
color. Females are larger (65-70 mm.) than the
males (60-65 mm.), more pale and have the
hindwing submarginal single row of white spots
expressed weakly on the dorsal surface.
H. lineatus is confined to Central America
where it is recorded from northern Panama to
southern Mexico. The form libitinus Staudinger
1885-88:80 has not been seen.
Specific Characters: The restriction of an-
droconia to hindwing veins Sc + R1 and to the
proximal half of Rs (Text-fig. 77); the deflexed
dorsal process of the ventral component of the
male genital valves (Text-fig. 35) and the color-
pattern.
6. Heliconius earns Hewitson 1861:155
Map 4: Text-figs. 36, 77, 150, 161
All the known forms of this species seem
sympatric and hence polychromatic but this can
be attributed to lack of precision in the locality
data, for they are all confined to the little-known
eastern slopes of the Andes in Colombia,
Ecuador, Peru and Bolivia. It is a small butterfly
with a wingspan of about 64 mm.
H. eanes has an eastern interface with H.
tales from which it can be immediately distin-
guished by the only single row of sub-marginal
ventral hindwing spots, compared with the
double row in H. tales. The cream forewing
band is always compact and centered over the
apex of the discal cell but it varies considerably
in size by being composed of B alone, or A + B
(Text-fig. 11). There is variable expression of
a yellow and red costal spot, a hindwing costal
streak which is yellow inside the humeral branch
of the sub-costa and red beyond, and a group
of red basal spots similar to those of H. lybius
lybius but which are usually masked by ray
(Text-fig. 119).
The known forms include eanes Hewitson
1861:155 which has a reduced forewing band
distal to the discal cell (B), dennis (Turner &
Crane, 1962) (Text-fig. 5) and full development
of an erato- type ray (Text-fig. 6); riff art hi Stichel
1 903 : 3 1 and aides Stichel 1 903 : 30 without dor-
sal dennis or ray; eanides Stichel 1903:30 which
is similar to eanes but with a larger band over
the apex of the discal cell (A + B); farragosus
Stichel 1903:30 with minimal dennis; felderi
Stichel 1903:31 with a red forewing band and
dennis but reduced ray; and pluto Stichel 1903:
32 with dorsally only a red band.
Data from museum specimens are vague but
the most precise locality data are consistent with
the situation that has been demonstrated in some
sympatric dennis-rayed species like H. erato
and H. melpomene (Emsley, 1964), in which
the dennis and ray characters are typical of the
lower altitudes and are lost at the higher levels
in the river valleys. Though the museum data
do not actively support the suggestion that the
red banded forms are at the highest altitude,
as in H. erato and H. melpomene , they do not
preclude the possibility. It is interesting to note
that the red-banded forms have the postero-
dorsal process of the male valves more ventrally
curved that the others. As in H. tales, the fore-
wing band tends to become triangular in the
Colombian Andes.
Specific Characters: The restriction of
androconia to a barely perceptible line along
Sc + R1 and the proximal half of Rs of the
hindwing (Text-fig. 77), the male genital valves
(Text-fig. 36) and the color-pattern.
7. Heliconius isabellae (Cramer 1781-82:117)
Map 5; Text-figs. 14, 37, 78, 150, 161
From the extreme south of the range of this
species to the estuary of the Amazon river the
form dianasus (Hiibner 1806) has a small entire
white or cream forewing band in position D
(Text-fig. 11); a cream discal band in position
A, broad orange lines over the cubitus and 1A,
a variably developed cream hindwing bar in
position II (Text-fig. 1 1 ) and an apically con-
tiguous orange bar in position IV. The ground
color is dark brown. The ventral pattern is sim-
ilar but less intense and with a row of paired
white dots in position V which are just visible
dorsally and which are continued onto the tip
200
Zoologica: New York Zoological Society
[50: 14
of the forewing. There is an orange forewing
costal spot, and submarginal yellow hindwing
costal streak and an occasional trace of a red
basal spot in the angle between Sc -f R1 and Rs.
Though connected to dianasus by intermed-
iates, the characteristic form of the Guianas
and the Amazon basin as far as the upper trib-
utaries in the foothills of the Andes is isabellae
(Cramer 1781-82: 1 17) which has both the dis-
cal and distal forewing bands broken into spots,
the hindwing bar II is yellow or orange and the
ground color remaining in position III is broken
into spots. This form extends into the Magdalena
and Cauca Valleys of northern Colombia, into
western Colombia and marginally into western
Ecuador.
At the extremities of the range in the eastern
Andes, perhaps due to the relative isolation of
the valley systems, above 650 meters there is
considerable variation in the details of the color
pattern but which in principle is due to an in-
crease in the amount of orange. Named forms
from these localities include hippolinus Butler
1873:169, margaritiferus Stichel 1903:5, per-
sonatus Stichel 1903:5, brunneus Stichel 1903:6,
dissolutus Stichel 1903:6, pellucidus Srnka
1885:130, olgae Neustetter 1916:597 and vegi-
tissimus Stichel 1903:8.
Around the spurs of the northern Andes there
are detailed variations like perimaculus Boullet
& Le Cerf 1910:25, arquatus Stichel 1903:9
and spoiliatus Stichel 1903:9 from the Cauca
Valley and western Colombia; and ecuadorensis
Strand 1912:181 from western Ecuador.
In Central America H. isabellae extends up
as far as Mexico ( zorcaon Reakirt 1866:243
and adjustus Stichel 1903:11) and almost cer-
tainly it is from this stock that Cuba and Puerto
Rico have been colonized ( cleobaeus Geyer
1832:7), as well as Hispaniola, where the light
markings are all orange ( monochromus Boullet
& Le Cerf 1910:25). The island forms are usu-
ally smaller (60-72 mm.) than those from Cen-
tral America (72-85 mm.) but similar to those
from the South American mainland.
Specific Characters: The restriction of the
androconia to hindwing veins Sc + R1 and Rs
but with a spur along the Rs-Ml crossvein
(Text-fig. 78); the very blunt and short up-
turned process of the dorsal component of the
male genital valve (Text-fig. 37); and the color-
pattern.
THE LYBIUS GROUP
Group features are the appreciably acute
angle through which the slender signa is de-
flexed (Text-figs. 151-154); the lack of a hook
on the ventral process of the male genital valves
(Text-figs. 38, 39); the presence of androconia
on the membrane in the vicinity of Sc + R1 and
Rs. (Text-figs. 79, 80), and on forewing vein
1A; and the geniculate female abdominal pro-
cesses (Text-fig. 169).
8. Heliconius lybius (Fabricius 1775:460)
Map 6; Text-figs. 38, 79, 119, 151, 152, 169
The dorsal color-pattern of this butterfly is
basically similar to that of H. alipherus, but the
dark markings are so much broader that the
ground color appears to be the black rather
than the orange. The forewing orange markings
are restricted to a subterminal band, a very
broad wedge-shaped arc over both branches of
the cubitus and along the posterior border of
the forewing. On the hindwing there is a large
regular orange bar covering areas I-IV (Text-
fig. 12) which is not invaded by spikes of
peripheral brown as in H. alipherus and H. lin-
eatus. The markings appear ventrally but, like
the ground color, are very much paler. The fe-
males and males are approximately similar in
size (65 mm.) but the color is less intense in
the females.
The form lybius (Fabricius 1775:460) is
widely distributed in the Guianas and Amazon
basin. It is distinguished by a red forewing costal
spot, a yellow hindwing costal streak and two
or three red basal spots (Text-fig. 119). All the
red spots are also expressed on the dorsal surface.
The apparent distributional continuity be-
tween lybius and olympius (Fabricius 1793:
166), which is known from northern and west-
ern Colombia, western Ecuador, northern Pan-
ama, Costa Rica and Nicaragua, is dependent
upon very few specimens from the eastern
Cordilleras. The form olympius is similar in
pattern to lybius but lacks the red basal spots,
has the forewing costal spot yellow and has the
subapical forewing band pure white and more
oval in shape. Some specimens of olympius from
Central America, though typical in all other
respects, have a small red spot on the dorsal
surface of the location of the forewing costal
spot in lybius.
The form lybioides Staudinger 1876:99 is
similar to olympius but has the subapical fore-
wing band a pale orange, and has a most inter-
esting geographic distribution. Museum data
labels give only Sevilla Island, Burica Island,
Chiriqui, Veraguas, Bugaba, Lino and San
Mateo, which with the exception of the slightly
westward San Mateo are all on the southern
slopes of the Chiriqui volcano or the nearby off-
shore islands. It has a distribution similar to that
of H. hewitsoni and H. pachinus.
1965]
Emsley: Speciation in Heliconius
201
Specific Characters: The distribution of the
androconia over the membrane as well as the
veins in the region Sc + R1 and Rs, but with
the androconia more heavily concentrated on
the veins (Text-fig. 79) ; the shape of the male
genital valves (Text-fig. 38) (the valves of the
non-Amazonian lybioides and olympius have
shorter dorsal processes than those of the
Amazonian lybius) ; and the extremely acute
angle through which the asymmetrical signa are
curved (Text-figs. 151, 152).
9. Heliconius tales (Cramer 1775-1776:62
and 154)
Map 7; Text-figs. 10, 39, 80, 153, 154, 169
The most characteristic feature of this species
is the double row of white spots in positions IV
and V (Text-fig. 12) on the ventral surface of
the hindwing. There is a yellow forewing costal
spot and a hindwing costal streak which is proxi-
mally yellow and distally red. The macro-char-
acters include dennis and the absence or variable
development of a unique ray pattern which
overlies the veins (Text-fig. 10) ; both characters
may occur in combination with a spotted or
compact cream forewing band.
In the Guianas and lower Amazon the char-
acteristic forms are surdus Stichel 1903:27 with
reduced ray and tales (Cramer 1775-78:62)
with complete hindwing ray, both of which have
dennis and the cream forewing bands broken
into discrete spots. To the west of the lower
Amazon the non-ray characters become less com-
mon and the forewing band becomes compacted
so that near Teffe ray is almost always fully devel-
oped and the forewing band is more or less en-
tire. Hence, the form aquilifer Stichel 1903:28,
which has a partially coalesced forewing band
without ray, is uncommon in this area whereas
the rayed form pythagoras Kirby 1900:13 is
more abundant. Westward from Teffe the fore-
wing band is fully compact and always with ray
and to the southwest the band lies beyond the
discal cell (calathus Stichel 1909:178) whereas
to the northwest in eastern Ecuador and Colom-
bia it is centered over the apex of the discal cell
(heliconioides C. & R. Felder 1861:102). As in
the other yellow-banded dennis-rayed species
the presence of ray and dennis breaks down in
central Colombia and western Venezuela, and
specimens with compact triangular forewing
band and reduced ray are known from that
region (cognatus).
In the northern Colombian forms like crystal-
inus Hall 1921:279 and xenophanes C. & R.
Felder 1865:377 the ray is replaced by a solid
proximal red area which appears to be composed
of bars I-III (Text-fig. 12).
Some specimens of H. tales from Santarem
have ray and dennis stone colored.
Specific Characters: The even distribution
of the androconia over the veins and membrane
on the Sc+Rl and Rs area of the hindwing
(Text-fig. 80) and on vein IA of the forewing,
the shape of the male genital valves (Text-
fig. 39), and the shape of the signa (Text-figs.
153, 154).
Subgenus Heliconius Kluk 1802:82
Subgenotype: H. charitonius
(Linnaeus 1767:757)
Definition: Heliconius with a very short broad
duct leading from the spermathecal diverti-
culum (Text-figs. 16, 17); five segmented
tarsi on the female foreleg (Text-fig. 13); the
presence of androconia on the membrane
around the hindwing veins Sc + R1 and Rs
as well as upon them (Text-figs. 30, 31); a
90 degree or less angle through which the
symmetrical signa of the bursa copulatrix are
curved (Text-figs. 26, 27); and finely pointed
meso- and meta-pretarsal paronychia (Text-
figs. 19-21).
THE NATTERl GROUP
Group features are the unique distribution
of androconia over many hindwing veins with-
out their encroachment onto the membrane
(Text-fig. 81), the absence of signa (Text-fig.
28) and the almost straight female abdominal
processes (Text-fig. 161).
10. Heliconius natteri C. & R. Felder 1865:375
Map 8; Text-figs. 45, 81, 120, 161
H. natteri is known only by a very few male
specimens from Bahia in eastern Brazil. It is
dark brown with a single oblique yellow fore-
wing band distal to the discal cell, a broad yel-
low forewing line along the cubitus, and on the
hindwing a dorsal and ventral yellow bar in posi-
tions II and III. There is a red costal forewing
spot, a yellow hindwing costal streak, and a pair
of red basal spots (Text-fig. 120).
H. fruhstorferi Riffarth 1899:406 is also
known by very few specimens but which are all
female and from either Esperito Santo or Per-
nambuco. The color pattern is similar to that
of natteri except that the forewing line over the
posterior margin of the forewing is orange, the
yellow bar is restricted to position II of the hind-
wing and may be overprinted with orange, and
there is an orange submarginal border to the hind-
wing in position IV. The minor characters are
similar. The apparent allopatry of the sexes may
not be a serious objection to their synonymic
association for there are probably not more than
202
Zoologica: New York Zoological Society
[50: 14
eight specimens of either sex known. The states
of Bahia and Esperito Santo have a common
boundary and the localities of fruhstorferi strad-
dle that of natteri, so as acute sexual dichro-
matism is uncommon in Heliconius it is probable
that they are dichromatic morphs not directly
associated with sex, as is already known in H.
ethillus and H. isabellae. Both sexes have a wing-
span of about 80 mm.
Specific Characters: The group features
serve also as specific characters together with
the structure of the male genital valves (Text-
fig. 45).
THE HIERAX GROUP
Group features are the androconia on the
hindwing cubitus (Text -fig. 82), the short signa
of the bursa copulatrix (Text-fig. 155), and the
almost straight female abdominal processes
(Text-fig. 161).
1 1 . Heliconius hierax Hewitson 1869b: 1 1
Map 2; Text-figs. 44, 82, 121, 155, 161
Heliconius hierax is known by a small number
of uniform specimens from the valleys of the
eastern Ecuadorian and Colombian Andes at
altitudes between 1,000 and 1,300 meters. It is
a medium-sized butterfly (wingspan 78 mm.)
with yellow forewing bands in positions B and E,
vague dennis posterior to the cubitus, and a red
bar on the hindwing in coalesced positions I +
II. The forewing bands are expressed ventrally
together with a red forewing costal spot, but
the hindwing has only a yellow costal streak, a
red basal spot complex like Text-fig. 121 and
paired intervenal white streaks emanating from
submarginal white spots. The forms semibrun-
neus N iepet 1923:96 from Ecuador and cinereo-
fuscus (Goeze 1779:122) from Surinam (!)
have not been examined.
Specific Characters: The unique male geni-
tal valves (Text-fig. 44), together with the group
characters.
THE GODMANI GROUP
Group features are the narrow arcuate signa
(Text-fig. 156), the coarsely denticulate dorsal
component of the male genital valves (Text-figs.
52, 53, 54), the extensive anterior area of the
hindwing invested with androconia (Text-figs.
83, 84, 85) and the almost tubular spermatheca
(Text-fig. 17). Each abdominal segment has a
conspicuous yellow spot on the middle of each
side. The female abdominal processes are strong-
ly curved (Text-fig. 165).
12. Heliconius godmani Staudinger 1882:397
Map 8; Text-figs. 17, 52, 83, 156, 165
Heliconius godmani is one of the few species
in the genus that has the alary color-pattern on
both dorsal and ventral surfaces similar and
equally well developed. The ground color is a
matt dark brown with the forewing band com-
posed of widely separate yellow spots, to which
is added a submarginal single row of yellow
fore and hindwing spots and an orange bar in
hindwing positions II + III. There are no basal
spots, only a vestige of a yellow forewing costal
spot and a reduced hindwing yellow costal streak.
H. godmani is known from very few museum
specimens, all of which have been taken from
near Rio San Juan in western Colombia. The
sexes are alike and have a wingspan of about
80 mm.
Specific Characters: The isolated male
genital valve (Text-fig. 52) is hard to distingu-
ish from that of the other members of the group,
but a valve of this type wedded to a godmani
color-pattern is diagnostic as is the unique dis-
tribution of hindwing androconia (Text-fig. 83).
13. Heliconius aoede (Hiibner 1816:12)
Map 9; Text-figs. 53,85, 126, 156, 165
In the Guianas and along the lower tributar-
ies of the Amazon the broken yellow forewing
band combined with dennis may occur with
an erato- type ray (Text- fig. 6) on the hindwing
(aoede) or without one (astydamius Erichson
1848:595). As one travels westward towards
Teffe, the frequency of the rayed individuals
increases to 100% and the forewing band be-
comes compact and entire. The shape of the
compact band may be short and broad (bartletti
Druce 1876:219) or long and broad (lucretius
Weymer 1890a: 290) but both seem sympatric
dichromatic forms occurring in the upper west-
ern tributaries of the Amazon up to about 800
meters. The more southern tributaries have the
forewing band short and narrow (cupidineus
Stichel 1906:31). The sexes are alike and have
a wingspan of about 75 mm. All forms have a
dark brown matt ground color, dennis, a reduced
hindwing costal streak and pure white head
markings. The forewing costal spot is masked by
dennis so it is probably red and the basal spots
are only faintly visible in non-rayed individuals
(Text-fig. 126). Most specimens have more or
less well developed paired intervenal white spots
around the margin of the ventral surface of the
hindwing. The rays are broader in the south-
western part of the range.
Specific Characters: The male genital
valves are hard to distinguish from those of the
1965]
Emsley: Speciation in Heliconius
203
other members of the group (Text-fig. 53) but
in combination with a dennis-ray color pattern
they are diagnostic. The hindwing androconial
distribution is also unique (Text-fig. 85).
14. Heliconius metharme (Erichson 1848:595)
Map 8; Text-figs. 54, 84, 156, 165
Heliconius metharme has a dark blue dorsal
ground color with a barely perceptible irides-
cence and a pair of forewing bands in positions A
(but not reaching the apex of the discal cell) and
D. There is a very strong erato- type (Text-fig. 6)
ray pattern on the ventral surface of the hind-
wing and a series of paired intervenal blue and
white streaks on the dorsal surface, the distal
extremities of which are expressed ventrally in
white. The forewing costal spot and hindwing
costal streak are both yellow and there is a fore-
wing ventral yellow line posterior and parallel to
the radius. The sexes are alike and have a wing-
span of about 82 mm.
This species seems most common in the mid-
dle Amazonian region where it bears a strong
resemblance to the sympatric H. doris meth-
arminae but from which it may be distinguished
by the more proximal position of the inner fore-
wing band, the stronger ray pattern and the yel-
low forewing costal spot and hindwing costal
streak.
Specific Characters: Though the genital
valves are similar to those of the other species in
the group, they are diagnostic in a dorsally blue
butterfly (Text-fig. 54) . The distribution of hind-
wing androconia is unique (Text-fig. 84).
THE WALL AC El GROUP
The group is characterized by the elongate
shape of the denticulate dorsal process of the
male genital valve (Text-figs. 40, 41, 42), the
short posterior process of the signum and the
rounded angle through which it is curved (Text-
fig. 157), and the extensive distribution of andro-
conia around Sc + R1 and Rs of the hindwing
(Text-figs. 86, 87, 88). The ventral process of
the meso and meta paronychia is about half as
long as the dorsal process (Text-fig. 20), and
the female abdominal processes are gently curved
(Text-fig. 162).
15. Heliconius wallacei Reakirt 1866:242
Map 10; Text-figs. 20,41, 86, 124, 157, 162
This is a large (82 mm. wingspan) dorsally
iridescent blue butterfly with a discal and distal
yellow forewing band in positions A and D, and
a yellow line along the radius and cubitus veins.
Ventrally there is a characteristic red basal spot
complex (Text-fig. 124), a red costal spot on the
forewing, a yellow and red hindwing costal spot
enclosed by the recurrent branch of the humeral
vein, a yellow line along the cubitus veins and a
series of variably developed paired intervenal
white streaks on the hindwing which emanate
from marginal white spots.
Though of wide distribution in South Amer-
ica east of the Andes, there is geographic varia-
tion only in the shape of the forewing band A
and in the prominence of the white streaks on
the ventral surface of the hindwings. In the
northern and northeastern parts of its range the
forewing band is long narrow and rectangular
(wallacei) (= mimulinus Butler 1873:168); in
Trinidad and the northeastern Guianas the band
is basically similar to that of wallacei but is
broader and more pointed at the posterior ex-
tremity ( kayei Neustetter 1929:83), whereas in
the southern Guianas, Lower Amazon and west-
wards to the slopes of the eastern Andes up to
about 1,200 meters, though at this altitude the
species is rare, the forewing band is broadly oval
( flavescens Weymer 1890a: 292). In the Gui-
anas and Lower Amazon, forms in which the
yellow of the forewing bands is replaced by white
have been named clytius (Cramer 1775-76: 103)
and similar white-banded forms with the north-
ern band shape are know as elsus Riffarth 1899:
407. From a number of localities in the Lower
Amazon specimens are known in which the fore-
wing band is variably reduced to two, three or
four smaller rounded spots, named colon Wey-
mer 1890a: 291, parvimaculatus Riffarth 1900:
207, and quadrimaculatus Neustetter 1925:14,
respectively. A specimen has been seen from
British Guiana (B.M. Tring collection) in which
the pair of forewing bands are enlarged and
fused into a large rectangular cream band which
occupies almost half the total area of the fore-
wing. Another aberration is halli Kaye 1919:217
from Serpa which has a short narrow white dis-
cal band. Specimens have also been seen which
lack the blue iridescence.
Specific Characters: Androconia on fore-
wing veins Ml, M2, M3, Cula, Culb and 1A,
and on hindwing veins Ml, M2, M3, Cula and
Culb, and on Sc + R1 and Rs and on the mem-
brane around them (Text-fig. 86); the shape of
the male genital valves (Text-fig. 41); and the
red basal spot complex (Text-fig. 124).
16. Heliconius burneyi (Hlibner 1816:12)
Map 11; Text-figs. 42, 87, 125, 157, 162
Heliconius burneyi has a matt dark brown
ground color with red dennis posterior to the
subcosta, with or without hindwing ray and a
variable yellow forewing band. The minor char-
acters are a red forewing costal spot, a red and
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Zoologica: New York Zoological Society
[50: 14
yellow costal streak contained by the recurrent
hindwing subcosta, a red basal spot complex as in
Text-fig. 125, and paired white radiating streaks
which emanate from white marginal spots on the
ventral surface of the hindwing. The forewing
costal spot and basal hindwing spots can be iden-
tified in individuals carrying dennis and ray by
the magenta color of the red. The dorsal ground
color lacks the iridescence of H. wallacei and the
matt brown ventral ground color lacks the pearly-
ness of H. egerius. A further point of contrast
with H. egerius is the less pointed but broader
and more regular wing shape (Text-figs. 123,
125).
In the Guianas and Lower Amazon the fore-
wing band is distinctly divided into a group of
three yellow spots which may be combined with
a very reduced ray pattern on the hindwing
( catherinae Staudinger 1885:79) or with a fully
developed erato- type ray (burneyi), (see Text-
fig. 6). Towards the western part of the range
full development of ray becomes a constant fea-
ture and the forewing band becomes compact
just proximal to the apex of the discal cell in
position A ( huebneri Staudinger 1896:312). In
south-central Colombia, though the ray pattern
is reduced almost completely, the forewing band
is still compact ( lindigii C. & R. Felder 1865:
377). There is variation in all localities in the
density of expression of both dennis and ray on
the ventral surface, but specimens from the ex-
treme western situations have stronger rays and
reduced forewing bands. The sexes are alike and
have a wingspan of about 90 mm.
Specific Characters: The restriction of an-
droconia to hindwing veins Sc + R1 and Rs and
on the surrounding membrane in the pattern
shown in Text-fig. 87, the shape of the male
genital valves (Text-fig. 42), and the basal spot
complex (Text-fig. 125) together with the pres-
ence of a red forewing costal spot.
17. Heliconius egerius
(Cramer 1775-76:54, 152)
Map 12; Text-figs. 40, 43, 88, 123, 157, 162
This species is very similar to H. burneyi in
appearance but ventrally the wings are a pearly
brown which is interrupted only by the forewing
band, a yellow costal spot and hindwing costal
streak, and faint basal spots in red (Text-fig.
123). In the Guianas and Lower Amazon the
yellow forewing band is always broken up into
separate spots over the positions A + B + C,
but the hindwing may present a broad red dorsal
bar which obscures or just does not obscure a re-
duced ray pattern (egerius), or a fully developed
erato- type ray which is usually without a bar
(hyas Weymer 1884:26). A variety of egerius
from French Guiana in which red markings are
buff has been named clearistus (Oberthiir 1923:
304). The status of egerides Staudinger 1896:
3 1 1 has not been ascertained. To the west of the
range the forewing yellow band is rectangularly
compact, almost entirely distal to the discal cell
(positions B + C) and with a fully developed
erato- type ray on the hindwing but without the
basal bar (astreus Staudinger 1896:311).
Judging by museum specimens, H. egerius is
not a common species and has been recorded
only along the Amazon and its lower tributaries
east of Sao Paulo de Olivenca and eastward into
the Guianas. Though known from only a rela-
tively small number of localities, it seems that
broken band is characteristic of the Guianas and
Lower Amazon and that full development of
ray only rarely extends into this area where bar
is common. The sexes are alike and have a wing-
span of about 90 mm.
The form astreus is especially interesting for
it has an additional dorsal process at the base of
the male genital valve (Text-figs. 40, 43).
Though such an intraspecific genital variation
seems most uncommon in Heliconius, it is similar
to that described in Papilio dardanus from west
and east Africa (Turner, Clarke & Sheppard,
1961), and it does not seem a sufficient reason to
erect a distinct species here. Unfortunately the
number of specimens is small and the few speci-
mens that are known from the likely interme-
diate localities have not been examined for this
character.
Specific Characters: The male genital
valves (Text-figs. 40, 43), the yellow forewing
costal spot and the relatively extensive hindwing
yellow costal streak, the wing shape (Text-fig.
123), the extensive distribution of androconia
in the vicinity of Sc + R1 and Rs of the hindwing
(Text-fig. 88), and the pearlyness of the ventral
ground color.
THE DORIS GROUP
Group features are the relatively small curved
signa of the bursa copulatrix (Text-fig. 27); the
subequal paronychial processes (as Text -fig. 19);
and the predominantly red hindwing costal
streak (Text-fig. 122). The female processes are
only gently curved (Text-fig. 163).
18. Heliconius doris (Linnaeus 1771:536)
Map 13; Text-figs. 7, 9, 27, 55, 89, 122, 163
The typical form of doris (= caeruleatus
Stichel 1906:35) is a black butterfly with about
an 86 mm. wingspan which has discal and distal
yellow forewing bands in positions A and E, and
with a more or less well developed hemistellate
bright blue patch on the dorsal surface of the
1965]
Emsley: Speciation in Heliconius
205
hindwing (Text-fig. 9). Dorsally and ventrally
the forewing has a yellow line along the cubitus
and ventrally a red costal spot. The hindwing has
a red, or red with minimal yellow, costal streak,
a weakly developed erato- type red ray pattern
which may obscure the red basal spots (Text-fig.
122), and variably developed paired intervenal
ventral white streaks which emanate from paired
white submarginal spots which are normally
present on both wing surfaces. The hindwing
also has paired marginal white fringing spots.
The typical blue form of doris extends com-
monly over the whole of tropical South America
including the Amazon basin, the Guianas, Vene-
zuela and the northeastern Andes. At the upper
limits of the range in eastern Ecuador specimens
are known in which the yellow of the forewing
band is replaced by white ( gibbsi Kaye 1919:
217), or is translucent ( tectus Riffarth 1900:
207). The amount of blue is variable in all lo-
calities and the extreme of reduction in which the
blue is barely perceptible has been named meth-
arminae (Staudinger 1896:315) because of its
similarity to H. metharme (No. 14).
North of western Venezuela into Central
America, though the hindwing is still dorsally
blue the discal yellow band is narrowed anteri-
orly over the apex of the discal cell and the ven-
tral red rays are less strongly developed ( aristo -
mache Riffarth 1901:131). The reduction of the
forewing bands may reach an extreme in which
they are scarcely visible ( obscurus Weymer
1890a:290), a condition which may also occur
in the doris zone.
From Surinam to Nicaragua at variable but
normally low frequency there are forms in which
some of the blue scales of the hemistellate hind-
wing patch are replaced by green or yellow ones,
though they are in other respects quite normal.
Individuals may have the majority of the scales
in this area yellow with the minority green (viri-
dis Staudinger 1885-88:77), with the majority
green and the minority yellow ( viridanus Stichel
1906:35) or with the yellow;, blue and green
scales equally represented ( virescens Riffarth).
As judged by museum specimens, these green
forms are most common in Panama and northern
Colombia and experiments conducted in Trini-
dad (Sheppard 1963:148) have shown that the
green form is truly polychromatic with both the
blue and erato- rayed form (see delilae below),
for at least two forms can be obtained from the
same clutch of eggs. Also in Panama are speci-
mens of aristomache in which there are some
white scales mixed in with the hindwing blue
( luminosus Riffarth 1901:132).
Throughout the Amazon and Orinoco basins
there is a polychromatic character in which the
blue of the doris- zone hindwing is overlayed by
an erato- type (Text-fig. 6) red ray pattern, either
completely ( delilae (Hiibner 1806-19)) or with
the blue visible at the margins of the red rays
( amathusius (Cramer 1777:124, 147)). To-
gether with the erato- type ray there is a redden-
ing of the dorsal surface of the forewing poste-
rior to the radius as in “dennis” (Turner & Crane,
1962:144) (Text-fig. 5). North of northwestern
Venezuela in the aristomache- zone there is also
a red ray character, but in which the rays are
comb-like (Text-fig. 7) and in which according
to its development the underlying color may be
completely obscured by the rays ( eratonius
Staudinger 1896:314, 317) or the blue or green
may be marginally visible ( transiens Staudinger
1896:314,317). The presence of dennis in these
rayed individuals decreases both in development
and frequency as one proceeds north until in
Nicaragua it is absent, hence the dennis associ-
ated with the northerly eratonius- type rays never
reaches the intensity or extent of that associated
with the southerly delilae-type rays.
Specific Characters: The shape of the male
genital valves (Text-fig. 55); the unique blue or
green ray pattern as in Text-fig. 9; and the pre-
dominently red hindwing costal streak (Text-
fig. 122).
THE H ECU BUS GROUP
Group features are the dense androconia
along hindwing veins Sc + R1 and Rs and on the
membrane around them (Text-figs. 90, 91); the
shape of the male genital valves (Text-figs. 56,
57) and the almost straight female abdominal
processes (Text-fig. 163).
19. Heliconius hecubus Hewitson 1857
Map 14; Text-figs. 56, 90, 99, 159, 163
This is a blackish-brown butterfly with a wing-
span of about 85 mm. with only a trace of iri-
descence in the ground color. The forewing
bands are narrow in positions C and E (Text-
fig. 11) and show a strong tendency to break up
into spots. There is also on the ventral surface of
the forewing a pearly-yellow line just anterior to
the cubitus and a brown costal spot. The hindwing
has a broad yellow bar made up of coalesced
radially elongate spots in position IV (Text-fig.
12), a submarginal border of paired intervenal
white streaks and, ventrally only, a silver-yellow
bar in position II which is separated from the
yellow bar in position IV by russet brown in po-
sition III. There is also a pearly-yellow hindwing
costal streak but no red basal spots.
Though the species seems confined to north-
ern Colombia and the eastern slopes of the east-
ern cordilleras of Colombia and Ecuador, the
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Zoologica: New York Zoological Society
[50: 14
scanty locality data are difficult to interpret. It
seems likely that the forms hecubus , cassandrae
C. & R. Felder 1862:419, and choarinus Hewit-
son 1872:83 occur sympatrically in the lower
Magdalena Valley and along the eastern Andes.
At first sight they appear to differ markedly in
the positions of the bars on the hindwing but the
differences can be attributed directly to the varia-
tion in the length of the stems of the veins that
bound the discal cell. In hecubus the discal cell
is very small and hence exceptionally proximal
in position, a trend that is present but to a lesser
degree in cassandrae and choarinus so the ele-
ments of the hindwing pattern are more distal
and less elongate. The form choarinus differs
from cassandrae principally in that the brown be-
tween the yellow hindwing bars II and IV is con-
tinued round to position I anterior to the discal
cell. The transitional stages can be seen in inter-
medius Riffarth 1907:509. The form tolimus
Fassl 1912:55 is similar to cassandrae but the
forewing bands are yellow and not white. Some
specimens have a few yellow scales on the dorsal
surface in the position of the forewing lines and
hindwing bar II. These may be the heterozygotic
expression of the characters discussed below.
From the Cauca, and perhaps from the Mag-
dalena Valley too, there is a broken yellow
banded form ( crispus Staudinger 1885-88:76)
which is like choarinus but the hindwing bar in
position IV is reduced to a row of small spots
and the yellow bar in position II is enlarged and
expressed fully on the dorsal surface. The re-
maining light markings may be expressed in
white ( crespinus Kruger 1925:151), but either
form may have the brown bar in position III ex-
tending into position I or not. The hindwing dis-
cal cell is normal in size.
Specific Characters: The male genital
valves (Text-fig. 56) cannot be distinguished
with certainty from those of H. xanthocles but
the color pattern is diagnostic. The signa are
broader, with up to eight rows of teeth, than any
other species and are relatively larger (Text-fig.
159), and the forewing has androconia on many
veins (Text-fig. 99) .
20. Heliconius xanthocles Bates 1862:561
Map 14; Text-figs. 57,91, 127, 158, 163
This species is one of the complex that has a
yellow forewing band in combination with den-
nis with or without an erato- type ray (Text-fig.
6). It is essentially Amazonian though it extends
into the Guianas where it is dichromatic in that
xanthocles has a broken yellow band in position
A— C, a distal band in position E (Text-fig. 11)
and dennis but no ray, whereas the sympatric
valus Staudinger 1885-88:78 is similar but with
ray.
Towards the middle of the Amazonian region
the forewing band becomes less broken ( para -
plesius Bates 1867:540) and always with ray,
but in the upper Amazon, although ray is pres-
ent, the yellow forewing band is unbroken, com-
pact and without the outer yellow band ( melete
C. & R. Felder 1865:376).
H. x. xanthocles, valus and paraplesius are the
only forms of any species in this complex which
exhibit an outer yellow band with the exception
otH. melpomene (?) tumatumari Kaye 1906:53
which may be the result of a wild cross between
H. melpomene and H. xanthocles. The wingspan
is about 72 mm.
Towards the extremities of the eastern upper
tributaries but below 600 meters the forewing
band becomes regular and either narrow ( melit -
tus Staudinger 1896:307), or broad ( melior
Staudinger 1896:307). The area of greatest
variety is in south-central Colombia where den-
nis, ray and the compact forewing band facies
disappear as in the other species in the complex.
In all xanthocles specimens there are inter-
segmental abdominal yellow annuli and outside
the Guianas there is a small lateral yellow spot
on each abdominal segment, but never as con-
spicuous as in H. aoede (No. 13 ) . The light head
markings are always all white. The forewing cos-
tal spot is masked by dennis so it is presumably
red, the hindwing costal streak is red beyond the
recurrent branch of the subcosta and yellow
within, and the red basal spots can be seen only
with difficulty in specimens carrying ray (Text-
fig. 127).
Specific Characters: Though the male geni-
tal valves (Text-fig. 57) are similar to those of
hecubus, there are no androconia on the fore-
wing veins, and the signa are less gross (Text-
fig. 158).
THE NUMATUS GROUP
Group features are signa with a well devel-
oped and sharply angled posterior limb (Text-
fig. 26), androconia fairly evenly and heavily
distributed over the hindwing veins Sc + R1 and
Rs and the membrane around them (Text-figs.
92-97), male genital valves in which the dorsal
processes lie clearly exterior to the lobose ventral
processes (Text-figs. 46-51) and are only termi-
nally denticulate. The hindwing costal streak is
typically yellow and the forewing costal spot is
red, the paronychial processes are subequal in
length (Text-fig. 19) and the female abdominal
processes are curved at their base (Text-fig. 164).
1965]
Emsley: Speciation in Heliconius
207
21. Heliconius numatus
(Cramer 1780-82:17, 251)
Map 15; Text-figs. 48, 92, 101, 164
This is one of the so-called “tiger” patterned
species of Heliconius which are considered to
mimic sympatric members of the distasteful
groups Danainae and Ithominae. The pattern is
composed of very variable areas of yellow or
orange on a matt black ground color. The sexes
differ only in that females are usually slightly
more pale than males. The high degree of poly-
chromatism together with most striking geo-
graphic differentiation makes the accurate de-
scription of the diversity of pattern and color ex-
cessively complicated. Here, only the more char-
acteristic forms will be described, though the
named varieties that belong to the species will be
indicated together with their geographic distri-
bution.
The gross range of H. numatus extends from
southern Mexico to western Ecuador and on the
eastern side of the Andes as far as southern Bra-
zil. In southern Mexico, Guatemala, Honduras
and Nicaragua the form telchinius Doubleday
1847:104 is monochromatic with a pair of yel-
low-spotted forewing bands in positions B and
D (Text-fig. 11), and an orange base to the fore-
wing posterior to the subcosta except for the
black ground color over 1A and the proximal
portion of the discal cell. On the hindwing there
are orange bars in positions I + II and IV (Text-
fig. 12). Ventrally the pattern is similar but with
the addition of a series of paired intervenal white
spots around the posterior margin of the hind-
wing and around the submargin of the forewing.
There is also a variably developed single white
spot posterior to the distal extremity of each of
the hindwing veins Sc + R1 and Rs. There is a
red forewing costal spot, a short hindwing yel-
low costal streak but no red basal spots. The
wingspan is about 95 mm.
In a southerly direction through Costa Rica
and Panama to northern Colombia, telchinius
persists at a decreasing frequency in polychro-
matic complex which reaches monochromatic
stability only in western Ecuador. There the
form metaphorus Weymer 1884:24 is smaller
(wingspan 85 mm.), lacks the discal yellow
band (B) but has the distal half of the normally
orange base to the forewing replaced by yellow
(A), has reduced ground color markings on the
forewing and has full development of bars I, II,
III and IV on the hindwing.
The transitional forms from Central America
and northern Colombia include occidentalis
Neustetter 1928:258, faunus Staudinger 1885-
88:74, albofasciatus Neustetter 1907:181, her-
manni Riffarth 1899:407, fasciatus Salvin &
Godman 1877:62, de fasciatus Neustetter 1908:
264, immoderatus Stichel 1906:9, clarescens
Butler 1875:223, albucillus Bates 1866:88, is-
menius Latreille 1817: 125 and hoppi Neustetter
1928:237.
Only very few specimens are known from
Colombia east of the Andes and Venezuela but
those that are known lead directly to the forms
which are common in the Guianas and the Ama-
zon estuary where there is considerable poly-
chromatism in the expression of the discal fore-
wing band and the hindwing bars. There are
always three yellow distal spots which comprise
the outer band D. These specimens rarely exceed
a wingspan of 85 mm. The forms in the Guianese
complex include numatus, guiensis Riffarth
1900:198, melanopors Joicey & Kaye 1916:
425, melanops Weymer 1893:304, mavors Wey-
mer 1893:305, bouletti Neustetter 1928:239,
sylvaniformis loicey & Kaye 1917:89, and dif-
fusus Butler 1873:168.
The last two forms named above are transi-
tional towards sylvanus (Cramer 1781:143,
252) which occurs right across northern Brazil
and leads to braziliensis Neustetter 1907:180,
hopfferi Neustetter 1907:181 and robigus Wey-
mer 1875:382 which extend around coastal Bra-
zil to Santa Catharina. There is a dichromatic
form of robigus in which the orange of hind-
wing bar I + II is yellow. This form ethrus
(Hiibner 1825:35) is analagous with polychrous
in H. ethillus.
From the Amazon estuary the variation in a
westerly direction is only moderate and such
forms as geminatus Weymer 1893:299, superi-
oris Butler 1875:224, sincerus Riffarth 1907:
501, gordius Weymer 1893:312, zobrysi Fruh-
storfer 1910: 194, nubifer Butler 1875:224, miri-
fcus Stichel 1906:11, prelautus Stichel 1906:
10, translatus loicey & Kaye 1917:91 and tal-
boti loicey & Kaye 1917:88 differ mainly in the
proportions of orange to yellow on the forewings,
the forms at the highest altitudes having the
least yellow.
Specific Characters: The presence of andro-
conia on forewing veins 1A, Culb, Cula, M3,
M2, Ml and sometimes on R4 + 5 (Text-fig.
1 01 ), and on hind wing veins Ml, M2, M3, Cula,
Culb and the crossveins bounding the discal cell
as well as over Sc + R1 and Rs and the mem-
brane around them (Text-fig. 92). The male
genital valves are similar to those of H. ethillus
and H. aristionus but the ventral process is
shorter and more rounded and the dorsal pro-
cess is apically curved towards the midline (Text-
fig. 48).
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[50: 14
22. Heliconius aristionus Hewitson 1852
Map 16; Text-figs. 51, 93, 130, 164
This species is more restricted geographically
than either of the other “tiger” patterned Heli-
conius (H. numatus, H. ethillus). In the eastern
Andes and Upper Amazon it may reach a wing-
span of 95 mm. but in the Middle and Lower
Amazons it normally approximates to 85 mm.
Along the eastern slopes of the Andes from
Bolivia to Colombia the forms occupying the
highest altitudes, which in eastern Ecuador are
800 to 1,200 meters, are aristionus, the more red
splendidus Weymer 1893:334, the more exten-
sively orange bicoloratus Butler 1873:167 and
the larger spotted pratti Joicey & Kaye 1917:90.
All these forms are one shade of orange or red
brown over the whole area covered by dennis
and forewing bands A + B + C with a matt
black ground color and have a red costal spot,
a yellow and orange hindwing costal streak but
no basal spots. The sexes are alike.
The data are vague on museum specimens
but personal field experience suggests that the
forms with the distal portion of the forewing
band yellow are from slightly lower altitudes in
Ecuador and Colombia (messene Felder 1862:
418) and are the transitional forms between the
orange and black aristionus and the yellow,
orange and black forms with barred hindwings
that occur at the 600 meter level in Ecuador
and at corresponding ecological levels to the
north and south. These forms include euphra-
sinus Neustetter 1928:239, lepidus Riffarth
1907:503, euphone Felder 1862:418, junctus
Neustetter 1925:11, euphorbus Stichel 1923:
261, nephale Seitz 1916:594, gracilis Riffarth
1907:504, phalaris Weymer 1893:334 and eu-
phrasius Weymer 1890b:21, 116.
At 500 meters in eastern Ecuador the appear-
ance is quite typical of all the Amazonian forms
and though there is much variation in points of
detail, the common features are a three spot
distal yellow band on the forewing in position
D and a yellow transverse band in position B
(Text-fig. 11) which abutts against a more or
less complete orange base to the forewing. The
hindwing is almost completely orange with the
ground color persisting only as a row of an-
teriorly truncate spots in position III and as a
peripheral border. There are no white submar-
ginal spots but some specimens have a single
red basal spot (Text-fig. 130). Such Amazonian
forms as these have been named artemis Rif-
farth 1907:502, mints Weymer 1893:296, ser-
gestus Weymer 1893:339, peeblesi Joicey & Tal-
bot 1925:647, nebulosus Kaye 1916a: 194, auli-
cus Weymer 1884:19, tarapotensis Riffarth
1901:59, timaeus Weymer 1893:331, lenaeus
Weymer 1890:284, idalion Weymer 1893:337,
confluens Neustetter 1912:55, obscurior Stichel
1906:15, subnubilis Stichel 1906:14, ignotus
Joicey & Kaye 1917:89, humbolti Neustetter
1928:442, alexander Neustetter 1928:442.
Some specimens from this region have the dark
markings excessively large, the normally yellow
markings almost completely orange and the or-
ange pattern a red-brown. Examples of these
are pardalinus Bates 1862:555, lucescens Wey-
mer 1893:321, aurorus Bates 1862:555, leopar-
dus Weymer 1893:319, hippolus Hewitson
1867a, lyrcaeus Weymer 1890a: 286, elegans
Weymer 1893:326, arcuellus Druce 1874:156,
seraphion Weymer 1893:330, radiosus Butler
1873:166, coloratus Stichel 1919a: 119, dilatus
Weymer 1893:323, maeon Weymer 1890a: 287,
tithoreides Staudinger 1900:404, garleppi Neu-
stetter 1928:239 and possibly pretiosus Weymer
1893:325 and staudingeri Weymer 1893:324.
Though occurring at low frequency in the Up-
per Amazon, the forms isabellinus Bates 1862:
554, floridus Weymer 1893:329 and gradatus
Weymer 1893:353 are more common at the
lower levels, where they form a link with the
Lower Amazonian and marginally Guianan
forms paraensis Riffarth 1900:197, lotus Rif-
farth 1900:197, thielei Riffarth 1900:195, xing-
uensis Neustetter 1925:11, schulzi Riffarth
1899:405 and novatus Bates 1867:539.
Specific Characters: The presence of an-
droconia on hindwing veins Ml, M2, M3, Cula
and Culb but not on the veins bounding the
discal cell, and on Sc + R1 and Rs and on the
membrane around them (Text-fig. 93); there
are forewing androconia only on vein 1A. The
male genital valves (Text-fig. 51) are barely
distinguishable from some of the other members
of the group. Females are almost impossible
to assign to species unless with a characteristic
form of wing pattern.
23. Heliconius atthis Doubleday 1847:102
Map 16; Text-figs. 50, 95, 129, 160
This butterfly has a matt black ground color
with a yellow band near the middle of the discal
cell of the forewing (proximal to position A,
Text-fig. 1 1), a dorsal and ventral forewing yel-
low line over the cubitus, a white fleck between
the origins of R1 and R2 (position B) and on
the hindwing a yellow bar in position II and a
row of yellow and white spots in position IV
which are continued onto the forewing. Ven-
trally only there is a row of russet spots in
position V which also run onto the forewing, and
a series of paired intervenal marginal white
spots. There is a red forewing costal spot, a yel-
low hindwing costal streak and a single red
basal spot (Text-fig. 129).
1965]
Emsley: Speciation in Heliconius
209
The species is geographically restricted to
western Ecuador below 500 meters where it is
common and occurs with the similar patterned
H. charitonius peruvianus (No. 38). The sexes
are alike, very stable and have a wingspan of
about 76 mm.
Specific Characters: Within the group the
color pattern is the only diagnostic feature for
the male genital valves (Text-fig. 50) are similar
to those of some of the other members as is the
distribution of hindwing androconia (Text-fig.
95 ) . The larger radius of curvature of the signa
(Text-fig. 160) is barely detectable.
24. Heliconius ethillus Godart 1819:219
Map 17; Text-figs. 49, 94, 100, 130, 164
This is a “tiger” patterned Heliconius which,
like H. numatus, ranges from southern Mexico,
where it has a wingspan of about 95 mm., to
western Ecuador and southern Brazil where it is
about 10 mm. smaller. The geographic varia-
tion is considerable and, together with the wide-
spread polychromatism, makes the description
and identification of named forms very complex.
The sexes are similar but females tend to be
larger and more lightly marked than males. The
minor characters are relatively constant and in-
clude a red forewing costal spot, a yellow hind-
wing costal streak and a single red basal spot
(Text-fig. 130), and paired intervenal marginal
white spots around the posterior border of the
hindwing.
In southern Mexico, Guatemala, western Hon-
duras and Salvador the form fornarinus Hewit-
son 1854 is monomorphic and dorsally black
with a broken yellow forewing band in posi-
tions D + E and a more or less complete yellow
band in position A + B. Ventrally the forewing
pattern is expressed together with a pair of rus-
set bars on the hindwing in positions I + II and
IV, and a single white submarginal spot pos-
terior to the extremities of each of the veins
Sc + R1 and Rs. The form styx Niepelt 1921:19
has the forewing markings transluscent.
From Honduras there is a substantial change
in the appearance for fornarinus becomes an
uncommon element in a polychromatic popula-
tion which, through intermediates like discoma-
culatus Weymer 1890a: 289 and chry santis
Godman & Salvin 1881:146, merges into zule-
ikus Hewitson 1854 which is the characteristic
form of Costa Rica and Panama. Typically
zuleikus has completely spotted forewing bands,
an orange base to the forewing posterior to the
cubitus, and hindwing bars I + II + III + IV,
but it occurs with other forms which have the
forewing bands white and with varying stages of
reduction of the orange bar III (albipunctatus
Riffarth 1900:199, xanthicus Bates 1864:57,
jucundus Bates 1864:56 and dentatus Neustetter
1907:183).
At low frequency in Panama, but more com-
monly in northern Colombia, the discal yellow
forewing band becomes more compact like the
Guatemalan fornarinus , and the distal yellow
band is reduced to a single row of three spots.
These forms vary considerably in detail, particu-
larly in the development of the hindwing bars,
and include claudiae Godman & Salvin 1881:
145, melicertus Bates 1866:87, zygius Riffarth
1907:504, muzoensis Neustetter 1908:226, sem-
iphorus Staudinger 1 896 : 284, holcophorus Stau-
dinger 1896:285, eucherius Weymer 1906:70,
rebeli Neustetter 1907:182, semiflavidus
Weymer 1893:302, depunctus Boullet & LeCerf
1909:461, orchamus Weymer 1912:73 and jun-
ta nus Riffarth 1900:196.
On the eastern slopes of the Colombian Andes
and extending around the Guianian Highlands
to the Guianas and the Amazon estuary, the
forms recognized in northern Colombia become
modified to forms like estebanus Kaye 1913:
132, anderidus Hewitson 1852, metalilis Butler
1873:167 and mentor Weymer 1884:22, which
differ in that there is a row of ground color spots
in hindwing position III, the forewing band is
more convex distally and the interface between
the yellow and the orange is more diffuse.
In eastern Venezuela, Trinidad and the
Guianas there are dichromatic forms in which
the orange of the forewing is partially replaced
by yellow and the hindwing bar II is more or
less all yellow. Forms with excess yellow are
ethillus Godart 1819:219 and flavofasciatus
Weymer 1893:303. In Trinidad the specimens
previously referred to as “numata” should more
correctly be designated H. ethillus ethillus for
the yellow form and H. ethillus metalilis for the
brown form. The genetics of this dichromatism
has been studied by Sheppard (1963) and
Turner (unpublished).
In the Guianas and Lower Amazon there are
a series of forms which differ principally in the
nature of the interface between the yellow and
the orange of the forewing bands and in the
variety of expression of the hindwing bars. These
forms include eucomus Hiibner 1816:11, sul-
phureus Weymer 1 893 : 3 1 1 , hyalinus Neustetter
1928:238, cephallenius Felder 1865:373, num-
ismaticus Weymer 1893:303, vetustus Butler
1873:165, metellus Weymer 1893:290 boyi
Rober 1923:57. These forms have become more
stabilized in the Middle Amazon in spurius
Weymer 1893:309, fortunatus Weymer 1884:
21, ennius Weymer 1890a:283, nigrofasciatus
Weymer 1893:307 and aerotome Felder 1862:
210
Zoologica: New York Zoological Society
[50: 14
79, but in the upper tributaries they become
more discretejy differentiated into tyndarus
Weymer 1896:317, versicolor Weymer 1893:
317, concors Weymer 1893:317, jonas Weymer
1893:308, sisyphus Salvin 1871:413, clams
Michael 1926:191 and felix Weymer 1893:315
from the Bolivian and Peruvian Andes; quital-
enus Hewitson 1852 from eastern Ecuador; and
ithacus Felder 1862:418, hero Weymer 1912:
75, cajetani Neustetter 1908:265, vittatus Butler
1873:166, sulphureofasciatus Neustetter 1925:
11, nigroapicalis Neustetter 1925:12, indecisus
Joicey & Kaye 1917:91 and marius Weymer
1890b: 116 from the eastern valleys of central
Colombia. These last-named forms merge into
those already mentioned from northern Col-
ombia and Venezuela. None of these forms
reach the altitudes attained by H. aristionus.
From the Amazon estuary there is a cline in
a southeasterly direction leading around the
coast of Brazil as far as Santa Catharina. The
characteristic form is narceus Godart 1819:217
which is distinguished by the distal forewing band
being entire and white and the hindwing bars
I + II and IV being fully represented. There are
transitional forms like brunnescens Neustetter
1907:180 and flavomaculatus Weymer 1893:
340 in which the entire distal band is yellow.
The dichromatism noted in Trinidad occurs in
Brazil too, the forms polychrous Felder 1865:
375 and physcous Seitz 1913:378 having excess
yellow on the forewing and the hindwing bar
II fully yellow. There is excess of orange in
satis Weymer 1875:380.
Specific Characters: The presence of an-
droconia in males only on the forewing vein 1A
and the posterior margin (Text-fig. 100) and
only on hindwing veins Sc + R1 and Rs and on
the membrane around them. (Text-fig. 94). The
male genital valves are a poor character for in
the Amazonian and Brazilian populations the
dorsal process is not so elongate as in the Central
American forms (Text-fig. 49) and there is
likely to be confusion with those of the other
species in the group. Females are difficult to
assign with certainty in the Amazonian and
Guianian regions.
25. Heliconius hecale (Fabricius 1775a:254)
Map 21
This is a most easily recognizable species as
it carries on its black ground color only a white
forewing band in position A + B and a trio of
white spots in position D. A pair of specimens
from El Chorr, Venezuela, have the proximal
band in position B + C. Ventrally there is in
addition a russet forewing costal spot and line
along the radius, and on the hindwing a yellow
costal streak and a row of paired intervenal
white spots around the posterior border. Some
specimens show a faint ventral russet bar in
positions I + II and IV as in H. ethillus fornar-
inus and H. cydtio. The form clearei Hall 1930:
278 differs only in the details of the forewing
band but fulvescens Lathy 1906:452 has a red-
brown base to the forewing and a red dorsal bar
in position I.
It is a large butterfly with a wingspan of 90
mm. which is known only from a few localities
in British Guiana, southeastern Venezuela, and
possibly Surinam and French Guiana. There is
a unique specimen in the collection of Barcant
(see page 192) which was authentically taken
near Rio Claro in Trinidad, but it is assumed to
have been an accidental introduction.
It is not known to what degree if any H.
hecale is geographically or ecologically isolated
from ostensibly sympatric forms of H. ethillus,
to which it is undoubtedly very closely related.
Specific Characters: It is morphologically
indistinguishable from H. ethillus, so the alary
color pattern is the only character known to be
of value.
26. Heliconius elevatus Noldner 1901:5
Map 19; Text-figs. 49, 93, 130, 160
This species is easily confused with H. mel-
pomene, as all the major components of the
alary color pattern are similar, even including
the association of hindwing bar I with forewing
dennis and the hindwing ray pattern (Text-fig.
8). In a previous paper (Ernsley, 1964), H.
elevatus elevatus and H. e. perchlorous were in-
cluded in H. melpomene in error.
H. elevatus seems restricted to the Upper
Amazon and the Andean valleys of Ecuador,
Peru and Bolivia. As is consistent with the other
dennis-rayed species that inhabit these areas, the
yellow forewing band is more or less compact
and centered over the apex of the discal cell at
the lower altitudes and distal to it at the higher
ones. All the known specimens have dennis and
ray expressed or both wing surfaces and ventral-
ly the forewing costal spot is obscured by den-
nis, so it is presumably red; the hindwing costal
streak is totally red, there is an arcuate yellow
line just posterior to the proximal half of Sc +
R 1 , the red bar I is expressed narrowly and there
are paired white submarginal spots around the
posterior border of the hindwing. The light head
markings are all white. There is one basal spot
as Text-fig. 130.
There is a long series of specimens in the
A.M.N.H. collection from Mt. Roraima, which
is near the Brazilian and British Guianese
border, which have all the morphological and
1965]
Emsley: Speciation in Heliconius
211
alary features of H. elevatus except that ray is
only expressed by a row of small spots which
represent the bases of the rays. The forewing
band is slightly more disperse. Temporarily these
forms are allocated to H. elevatus. The forms
perchlorus, schmassmani and aquilinus have not
been re-examined but probably belong to H.
elevatus.
Specific Characters: The presence of an-
droconia on hindwing veins Ml, M2, and M3 as
well as on Sc + R1 and Rs (as Text-fig. 93);
the shape of the genital valves which are in-
distinguishable from those of H. ethillus (Text-
fig. 49); the unusually large radius of curvature
of the signa (as Text-fig. 160); the red hindwing
costal streak; and the yellow line posterior to
the proximal ventral margin of Sc + R1 on the
hindwing.
27. Heliconius melpomene (Linnaeus 1758:467)
Map 18; Text-figs. 8, 19, 26, 46, 96, 131, 164
This species, together with H. erato, is ex-
ceptionally strongly differentiated into geo-
graphic races which in the areas between con-
trasting zones are highly polychromatic (Emsley,
1964).
In western Ecuador, Colombia, Central
America, Venezuela, Trinidad, southern Brazil,
southeastern Bolivia and in the deeper valleys
of the eastern Andes the forewing band is al-
ways red, but in the Amazon basin it is usually
yellow as is the forewing band of all the other
species of Heliconius in that region, with the
exception of H. hermathenae.
In western Ecuador and western Colombia
there is a yellow bar on the ventral surface of
the hindwing in position II (Text-fig. 12) to
which is added a similarly located dorsal bar
in northern Colombia, Central America, south-
ern Brazil, eastern Bolivia and the valley of the
Huallaga River in eastern Peru. There is a de-
creasing cline in the intensity of the blue irides-
cence from western Ecuador through northern
Colombia into Panama and Venezuela.
In the Guianas there is a polychromatic popu-
lation exhibiting the red forewing band, which
is typical of the northern races, in a large variety
of combinations with the broken yellow band
which is the characteristic feature of the popu-
lations of the Lower Amazon. All these com-
binations may occur with or without dennis,
which in H. melpomene has associated with it
a red hindwing bar in position I. Those with
dennis may or may not have radiating red rays
on the hindwing (Text-fig. 8). As one pro-
ceeds westwards the combination of dennis and
ray becomes more frequent until at Obidos and
beyond all specimens carry both. Simultaneously
the distinct group of forewing yellow band spots
begin to become coalesced, so by Teffe it is a
compact yellow rectangle almost completely dis-
tal to the discal cell.
In the valleys of the eastern Andes at about
650 meters the yellow forewing band becomes
discretely double and at about 850 meters the
color changes to red and white and dennis and
ray are lost. The altitudes quoted are based on
personal observation in the Pastaza valley in
eastern Ecuador and may differ from those of
other valley systems. At about the 1,300 meter
level in the Pastaza valley the timaretus Hewit-
son 1867:563 complex is exceptional, for the
members of it have a yellow forewing band and
either dennis and ray or ray alone (Text-fig. 8).
There are no other races known in which ray
occurs in the absence of dennis.
Each of the major valley systems of the
eastern Andes has a characteristic forewing
band shape. The broad bicolored red and yellow
band of heurippus Hewitson 1854 is from the
Guatiquia River in eastern central Colombia;
the double yellow band is from the Pastaza River
in eastern Ecuador between 650 and 850 meters,
and above this altitude it becomes red and white
or all red ( plesseni Riffarth 1907:333); the
Morone River in southeastern Ecuador is char-
acterized by a single distal oval yellow forewing
band ( ecuadorensis Neustetter 1908:267); the
Huallaga River forms have a large single red
band ( amarylis C. & R. Felder 1862:80) as do
those of the Upper Madre de Dios River ( eury -
ades Riffarth 1900:205), wheras those from the
Perene River ( xenocleus Hewitson 1852) have
large double all-red forewing bands. The details
of these races have been presented in Emsley,
1964.
So, in addition to the Guianas, it is in east-
central Colombia, the eastern Andes and in cen-
tral Bolivia that polychromatism is known, that
is, where the apparently stable Amazonian forms
meet the contrasting and stable peripheral pop-
ulations. In almost all forms the minor charac-
ters are relatively constant, for there is always
a red forewing costal spot and yellow hindwing
costal streak and the only exceptions to the basal
spot complex (Text-fig. 131) are some of the
forms isolated in the Huallaga and other Per-
uvian river valleys. In these cases specimens
from the highest altitudes lack the spots, which
are a variable feature in those from intermediate
levels.
The forms rubellius Grose Smith & Kirby
1892, wernickei Weymer 1906:8 and emilius
Weymer 1912:73 are held to interspecific hy-
brids between H. melpomene heurippus and H .
cydno, whereas seitzi Neustetter 1916:594 is a
212
Zoologica: New York Zoological Society
[50: 14
rare intraspecific hybrid between H. melpornene
heurippus and H. melpornene rosinus. The char-
acters of these forms are all either intermediate
between or combinations of those possesssed by
the suggested parental stock.
The Guianian forms tumatumari Kaye 1906:
53 (without ray) and bari Oberthiir 1902:23
(with ray) both possess a distal forewing yellow
band in addition to the broken yellow discal
band and are held to be interspecific hybrids
between H. melpornene and H. xanthocles. The
breeding capacity of these postulated wild hy-
brids is unknown.
In a recent communication. Dr. K. S. Brown8
has suggested that, contrary to the view ex-
pressed in Emsley (1964), besckei may be spe-
cifically distinct from H. melpornene narmus.
Both species appear to fly together near Brasilia
and on the east coast of Brazil, without the pres-
ence of specimens carrying intermediate or re-
combined characters.
Specific Characters : In respect of the group
characters like the signa (Text-fig. 26), female
abdominal processes (Text-fig. 164) and hind-
wing androconia (Text-fig. 96), H. melpornene
is quite typical and the only specifically useful
features are the male genital valves (Text-fig.
46), the basal spots (Text-fig. 131) and the
color pattern.
28. Heliconius cydno Doubleday 1847: 103
Map 19; Text-figs. 26, 47, 97, 164
Over its whole range the color pattern of this
species is subject to considerable geographic
and polychromatic variation, most of which
seems correlated with that of H. sapho (No. 45) .
The wing span of H. cydno approximates to 85
mm., but some of the valley forms may reach
95 mm.
The most northern form (galanthus Bates
1864:58) extends from British Honduras
through Guatemala, Honduras, Nicaragua and
Costa Rica. It has a bright blue iridescent dorsal
ground color with a single broad white distally
convex forewing band which is slightly incised
at the antero-dorsal angle of the discal cell.
The hindwing has a weak white border of rec-
tangular submarginal spots in position IV (Text-
fig. 12) which merge into a more strongly devel-
oped apical row in position V. Ventrally the
dorsal pattern is expressed together with a yel-
low hindwing costal streak and a pair of russet
sDr. K. S. Brown, Jr., Centro de Pesquisas de Produtos
Naturais, Avenida Pasteur 250, fundos, Rio de Janeiro
ZC-82, Brasil. Professor Brown would welcome Heli-
conius material from all sources for biochemical studies
of pigment and odor substances.
bars in positions I and III which form a nearly
closed U-shape. There is no forewing costal
spot and no trace of hindwing red basal spots.
At low frequency in Nicaragua and Guate-
mala the forewing band may be apically trun-
cate and yellow (diotrephes Hewitson 1869a: 33)
but with typical galanthus hindwing spots. From
Costa Rica to northern Colombia the hindwing
spots become more strongly developed by the
addition of a second row in position V which
are more pronounced posteriorly. These are as-
sociated either with a yellow apically truncate
forewing band or with a white distally convex
band which may be large (chioneus Bates 1864:
58) or small (exornatus Riffarth 1907:505).
The variation in forewing band and hindwing
border is carried into northern Colombia where
at the entrance to the Cauca and Magdalena
Valleys the characteristic type has a broad trun-
cate yellow band with a very strong hindwing
border consisting of large white submarginal
rectangular spots (cydno). This form extends
down the valleys and over the western and east-
ern cordilleras but its identity becomes lost in
combinations with other forms. On the western
side of the western cordilleras in Colombia the
dominent form is zelinde Butler 1869:17 which
has an apically truncate yellow band and very
weak white spots which are posteroventrally
confluent with fringing white scales as in galan-
thus. Further south the hindwing border be-
comes much more strongly expressed and in
western Ecuador it is a broad complete border
formed by coalesced bands III + IV + V. Forms
with this hindwing border are alitheae Hewitson
1869b: 10 which has a single yellow forewing
band emarginated in the discal cell, neustetteri
Riffarth 1908:114 which has the band partially
divided into three components, egregius Riffarth
1907:505 in which the three spots are separate,
and haenschi Riffarth 1900:200. The form aven-
tinus Oberthiir 1925:82 has the forewing bands
completely double and white but retains a hind-
wing border like alitheae.
In western Colombia there are a large number
of forms recorded which have various combina-
tions of forewing band and hindwing border, for
example, large yellow band with reduced white
border (bronchus Stichel 1906:21), fully con-
fluent double yellow bands and hindwing spots
barely visible ( flavidior Neustetter 1928:258),
double yellow bands with hindwing spots which
are small ( subcydnides Staudinger 1896:289),
medium ( cydnides Staudinger 1885-88:77) or
large ( epicydnides Staudinger 1896:289), dou-
ble white bands only ( albidior Neustetter 1928:
259), double white forewing bands and medium
width border ( aztekus Neustetter 1928:259),
1965]
Emsley: Speciation in Heliconius
213
and posteriorly confluent double white forewing
bands and medium width hindwing border ( con -
fluens Neustetter 1928:259).
In the terminal reaches of the Cauca Valley
there is a form with a virtually bandless forewing
and on the hindwing only a yellow bar in posi-
tion II ( gustavi Staudinger 1896:287). This
occurs together with forms in which the fore-
wing band shows characters which are inter-
mediate between either total absence and a
divided white band ( weymeri Staudinger 1896:
287), or absence and a spotted white band ( sub -
marginatus Fassl 1912:56). All these forms
show only a suspicion of the ventral russet U-
shape bars and the ventral costal streak.
In the Magdalena Valley there is a series of
forms in which the forewing band is broken up
into small spots with an additional submarginal
row of dots around the forewing margin. The
hindwing border in position IV is yellow. The
forewing band may be white or yellow and white
( hermogenes Hewitson 1857), or yellow ( lute -
scens Kaye 1916a: 194). Specimens exist in this
locality ( temerindus Hewitson 1873) in which
the white forewing band is intermediate between
the broken band of hermogenes and the broad
single band of chioneus.
If locality labels are to be trusted, some of
the characters which are typical of the Cauca
and Magdalena Valleys have spread slightly
over the cordilleras, which one would normally
expect to limit them. This is supported by forms
like submargincitus which combine weak expres-
sion of the hermogenes- type Magdalenan fore-
wing band with the Caucan hindwing bar II.
H. cydno may then be capable of existing at
higher altitudes than H. melpomene and H. erato,
both of which seem to find the Colombian cordil-
leras insurmountable barriers. This would sug-
gest that the interspecific hybrids postulated when
discussing H. melpomene have been made pos-
sible by invasions of H. cydno into the Guata-
quia Valley, where heurippus is found, rather
than the other way around.
It seems from the foregoing that none of the
named forms are monochromatically typical of
any one locality. In each area the species is at
least dichromatic with respect to either fore-
wing band, or hindwing border or both. Geno-
typic recombinations may give rise to either
recognizably intermediate characters or discrete
phenotypic recombinations, hence the large
number of named forms. The forms cydnides,
epicydnides and subcydnides have a wide distri-
bution in Colombia, as they are the double yel-
low band character combined with a series of
expressions of hindwing border. The most char-
acteristic forms seem to be galanthus from Cen-
tral America, chioneus and cydno from north-
ern Colombia outside the upper reaches of the
river valleys, hermogenes in the Magdalena Val-
ley, gustavi in the Cauca Valley, zelinde in west-
ern Colombia and alitheae in western Ecuador.
Specific Characters: As in H. melpomene,
the group features provide little of specific value
(Text-fig. 97) and the male genital valve (Text-
fig. 47) cannot be distinguished from that of H.
pachinus. The ventral hindwing russet U-shape
bars are useful but occur also in H. ethillus
fornarinus and very faintly in H. hecale.
29. Heliconius pachinus Salvin 1871:414
Map 16; Text-fig. 26, 31, 128, 164
This species shares its very restricted geo-
graphic distribution with the similarly colored
H. hewitsoni. Data labels examined have re-
vealed Chiriqui Volcano as the most common
locality, together with the off-shore islands of
Brava, Sevilla, Parida and Taboga. Other locali-
ties include Veraguas and Lion Hill in Panama,
and San Mateo, Pozoazul and Corillo in Costa
Rica.
The species differs from the sympatric H.
hewitsoni principally in the smaller size of the
red basal spot in the angle between Sc + R1 and
Rs (Text-fig. 128), the lack of a yellow line
along the ventral surface of the forewing radius,
and the more distal positions of both the outer
(E) and inner (B) forewing bands. Both species
have a red costal spot and a yellow bar on the
hindwing in position III. There is a red hindwing
costal streak. The wingspan approximates to 85
mm.
Specific Characters: The group features
are expressed quite typically, and morphological-
ly H. pachinus differs from H. cydno only in that
the androconia on the hindwing from a hooked
pattern distally (Text-fig. 31), but this pattern
also occurs in H. cydno weymeri so the only
characters of real value are the color pattern and
the unique red basal spot complex (Text-fig.
128).
THE HECALASIUS GROUP
Group features are the lack of signa on the
bursa copulatrix (Text-fig. 28); the poor devel-
opment of the dorsal process of the male genital
valves (Text-figs. 58-63, 65-66) ; the 2:1 propor-
tions of the lengths of the paronychial processes
(Text-fig. 20); the lack of androconia on the
forewing veins and their presence on hindwing
veins Sc + R1 and Rs, on the membrane around
them and usually on some other hindwing veins
(Text-figs. 102-108, 110); and the curved fe-
male abdominal processes (Text-figs. 165-168)
with the exception of H. telesiphe (Text-fig.
171).
214
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[50: 14
30. Heliconius hecalasius Hewitson 1853
Map 20; Text-figs. 58, 103, 166
This species extends from the Magdalena
Valley in northern Colombia, where it occurs
with the rather similar H. cydno hermogenes,
through Central America as far as Mexico,
where sexual dichromatism is much more pro-
nounced than in the south. Females are more
pale than males and have a more yellow antenna.
In the Magdalena Valley hecalasius has a non-
iridescent black ground color with scattered
yellow band spots and a peripheral row of sub-
marginal yellow spots on the forewing, and on
the hindwing a row of yellow spots in position
IV which enclose a russet patch which is most
intense at the anal angle. There is a yellow and
brown forewing costal spot and hindwing costal
streak but no basal spots. The only known local-
ity datum for gynaesius is Colombia, which if
accurate is most likely from the Cauca Valley.
The type has not been seen, nor any other speci-
men.
To the north in Panama, Costa Rica and
Nicaragua formosus Bates 1 863 : 247 has a great-
ly increased amount of orange on the hindwing
with consequent reduction in the size of the bar
IV yellow spots, and there is a trace of orange
at the base of the forewing posterior to the
cubitus.
In Guatemala, Honduras and southern Mex-
ico this trend is continued in octavius Bates
1866:86 which has even more orange and
smaller spots on the hindwing, more discrete
oblique forewing bands and more extensive
orange at the base. It is a pattern that is not
greatly dissimilar from that of the sympatric H.
lineatus.
Specific Characters: The male genital
valves (Text-fig. 58) are hard to distinguish
from those of H. longarenus (Text-fig. 59) but
only H. hecalasius has androconia on Ml and
M2 of the hindwing (Text-fig. 103) which are
most prominent on northern specimens; the
female processes are strongly curved (Text-fig.
166).
31. Heliconius longarenus Hewitson 1875:182
Map 20; Text-figs. 59, 104, 166
This species is known only by a few speci-
mens from western Ecuador and western Colom-
bia. The rather elongate forewings have a span
of about 90 mm. and the black non-iridescent
ground color carries a broad orange line over
the cubitus and a pair of oblique yellow bands
in positions B and D (Text-fig. 11), the distal
of which is continuous with a row of submar-
ginal yellow spots around the border of the wing.
On the hindwing there is an orange bar in posi-
tion II (Text-fig. 12) and a row of yellow spots
in position IV. The forewing costal spot and
hindwing costal streak are yellow and brown
and there is a white spot over the origin of the
cubitus and Rs. The appearance is generally
similar to that of H. hecalasius octavius or
gynaesius.
Specific Characters: The male genital
valves (Text-fig. 59) are useful when combined
with the absence of androconia from hindwing
veins other than Sc + R1 and Rs (Text-fig.
104). The female processes are strongly curved
(Text-fig. 166).
32. Heliconius hermathenae Hewitson 1853
Map 21; Text-figs. 61, 108, 136, 168
This red-banded species is particularly inter-
esting for its limited distribution along the lower-
middle Amazon where its sympatric species of
Heliconius are all of much wider range and few
of which exhibit a red forewing band. In appear-
ance H. hermathenae is very similar to H. chari-
tonius in that it has a broad yellow forewing
line over the cubitus, a red forewing costal spot,
a yellow hindwing costal streak, a group of basal
spots, some of which are expressed dorsally, a
yellow hindwing bar in position II and rows of
yellow dots in positions IV and V. But it differs
markedly by the replacement of the pair of yel-
low forewing bands in charitonius by a broad
B + C red band in hermathenae, the broader
and more rounded shape of the wings (wing-
span 80 mm.), the variably developed row of
ventral red spots posterior to the discal cell of
the hindwing (Text-fig. 136), and the lack of
the pearly-brown markings that are at the apex
of the charitonius hindwing. Some specimens
( vereattus Stichel 1912:1) have the forewing
band smaller, the yellow over the cubitus faint,
hindwing bars II and IV dorsally absent and
ventrally only discernible by a differentiation of
the brown ground color. This shadow effect of
the hindwing markings is similar to that demon-
strated as the heterozygous condition in H. mel-
pomene and H. erato (Emsley, 1964) and is
presumably the situation in this form too. The
precise relationship of Faro, which is the locality
for vereattus, to the rest of the range of herma-
thenae is not known but it seems likely that it
is near the perimeter.
Specific Characters: The male genital
valves are a good character (Text-fig. 61), and
the female abdominal processes are slender and
uniformly curved (Text-fig. 168); also there are
androconia on hindwing veins Ml, and M2 in
addition to the normal compliment on Sc + R1
and Rs (Text-fig. 108).
1965]
Emsley: Speciation in Heliconius
215
33. Heliconius himerus Hewitson 1867a
Map 20; Text-figs. 62, 102, 135
The forewing shape is broader and more
rounded than in most Heliconius and the wing-
span is about 75 mm. The black ground color
has a forewing yellow band in position A (Text-
fig. 11) but no costal spot, and on the hindwing
there is a red bar in position II (Text-fig. 12)
which is only weakly expressed on the ventral
surface, a ventral yellow costal streak and a red
basal spot complex (Text-fig. 135).
H. himerus seems sympatric with very few
other species of Heliconius, for it is known by
comparitively few specimens from a few local-
ities in southeastern Ecuador and northeastern
Peru at altitudes around 1,000 meters.
Specific Characters: Though similar to
those of H. erato (Text-fig. 60), the male genital
valves are characteristic in that the denticles
form a slightly flared margin to the tip of the
dorsal process (Text-fig. 62); there are andro-
conia on Ml, M2, and M3, but not on the mem-
brane around Rs (Text-fig. 102).
34. Heliconius erato (Linnaeus 1758:467)
Map 23; Text-figs. 21, 28, 60, 110, 140, 165
This species, together with H. melpomene, is
remarkable for its diversity in color pattern over
its very wide geographic range, for not only are
there races characteristic of different areas but
at the boundaries of zones which are charac-
terized by contrasting forms it is highly polychro-
matic. The genetics of some of the color pattern
components has been studied by Turner & Crane
(1962), Sheppard (1963) and Emsley (1964),
and the status of the different forms has already
been recorded (Emsley, 1964).
In essence, the situation is that in Central
America, central and northern Colombia, east-
ern, southern and southwestern Brazil and in
the valley of the Huallaga River in northeastern
Peru, though there are minor characters peculiar
to each area, the general pattern is one of a sin-
gle red forewing band in position A + B on an
iridescent blue or matt black ground color, with
a yellow bar on both surfaces of the hindwing
in position II. In eastern Colombia, Venezuela
and Trinidad the appearance is similar but the
yellow bar is lacking on both hindwing surfaces,
whereas in western Colombia and western Ecua-
dor it is lacking only dorsally. There is a cline
of decreasing blueness from a maximum in west-
ern Ecuador round the spurs of the Colombian
Andes to Panama and through the Guianas to
the Amazon basin where the ground color be-
comes matt black.
In the Amazon basin the characteristic form
has the proximal half of the forewing red (=
dennis, Text-fig. 5), the hindwing may or may
not have a red ray pattern that occurs in several
other species (Text-fig. 6), and the forewing
band is yellow and composed of a group of spots
over positions A-C (Text-fig. 11). The shape of
the band grades from a group of discrete spots
in the Guianas to a compact yellow rectangle
in position C in specimens from the upper tribu-
taries of the Amazon.
Above about 850 meters in the valleys of the
eastern Andes, red replaces yellow on the fore-
wing band and each valley has a distinctive band
shape that matches the sympatric forms of H.
melpomene very closely. The details of this mi-
metic situation have been presented in Emsley
(1964).
In the zones that are between areas with stable
but different characteristics, such as the Guianas,
central Colombia, the eastern Andes and central
Bolivia, the populations are polychromatic and
show recombinations of characters which are
typical of the neighboring zones together with
intermediate characters. It is these zones which
have been mainly responsible for the period of
taxonomic confusion through which both H.
erato and H. melpomene have passed.
Features common to nearly all the forms are
the red forewing costal spot, the yellow hindwing
streak and red basal spots (Text-fig. 140) which
reach maximum expression in southern Brazil
(H. erato phyllis). The light markings of the head
almost always contain some yellow. The wing-
span is about 75-80 mm.
Specific Characters: The male genital
valves are a good character (Text-fig. 60) ; there
are androconia on the membrane around both
Sc + R1 and Rs (Text-fig. 110). Except in speci-
mens from the valleys of the Cauca, Huallaga,
Perene and Ucayali Rivers there are always a
group of four basal spots which in southern and
eastern Brazil are carried out onto the disc (Text-
fig. 140); and the female abdominal processes
are curved and slender (Text-fig. 165).
35. Heliconius telesiphe Doubleday 1847:103
Map 12; Text-figs. 63, 105, 132, 171
Heliconius telesiphe is unusual in that the
paired forewing bands in positions A and E
(Text-fig. 1 1) are reddish-pink. There is bar on
the hindwing in position II which may be white
or yellow, a red costal spot, a yellow and white
hindwing costal streak, a group of red basal spots
(Text-fig. 132), and diffuse paired pale inter-
venal gray streaks on the ventral surface of both
fore and hindwings. The wings are elongate,
with a span of about 80 mm., and the hindwing
216
Zoologica: New York Zoological Society
[50: 14
has its posterior border scalloped but almost
straight (Text-fig. 132).
There is no doubt that it is an upland species,
and its range extends along the eastern Andes
between 1,000 and 2,600 meters from southern
Colombia to central Peru. It is either uncommon
or hard to catch, for it is not well represented in
museum collections. It is reasonably constant
over its whole range except for the color of the
hindwing bar which, north of about latitude 4°
S., is yellow ( sotericus Salvin 1871:413) but
which to the south is white (telesiphe). The ap-
parently mimetic relationship between Helicon-
ins telesiphe and the heliconiine Podotricha tele-
siphe is remarkable for not only do they occupy
an almost coincident distribution, but they each
have two grossly similar allopatric forms. Podo-
tricha telesiphe telesiphe (Hewitson 1867b:564)
has a white hindwing bar and occurs to the south
and P. t. tithraustes (Salvin 1871:415) has a
yellow bar and occurs to the north of the same
dividing line that separates the two forms of H.
telesiphe. There are no other species of Heli-
conius sympatric with H. telesiphe and it is the
only species of the genus which is known to ex-
ceed an altitude of 1,300 meters, except perhaps
H. cydno and members of the H. melpomene
timaretus complex.
There is a dichromatic form ( cretaceus Neu-
stetter 1916:597) in which the forewing bands
are white instead of red.
Specific Characters: The male genital
valves (Text-fig. 63) are indistinguishable from
those of some of the nearly related species, but
the occurrence of androconia on hindwing veins
1 A and 2A and M 1 is unique (Text-fig. 105); the
female abdominal processes are straight (Text-
fig. 171).
36. Heliconius clysonymus Latreille 1817:128
Map 22; Text-figs. 66, 106, 133, 167
This species has a single yellow forewing band
in position A (Text-fig. 11) on a non-iridescent
dark brown ground color, with an orange -red
bar in position II + III (Text-fig. 12) on the
hindwing which shows pink on the ventral sur-
face. There is a red costal spot, a hindwing yel-
low streak and three basal spots (Text-fig. 133).
The ventral ground color is brown with vague
paired pale intervenal light streaks on the hind-
wing and on the apex of the forewing. The wing-
span is about 80 mm., but smaller specimens are
known ( micrus Seitz 1913:395) which may be
as little as 60 mm.
The typical form, clysonymus, extends from
Panama through the western side of Colombia
as far as Rio Dagua, into the Cauca and Magda-
lena Valleys, and on the mountain slopes of the
eastern side of the eastern Cordilleras as far as
Caracas in Venezuela and down to Banos in east-
ern Ecuador. Though there are no precise data
available it seems to be restricted to between
500 and 1,300 meters. From Panama to the
known limits of the species in northern Costa
Rica the hindwing red bar becomes broader dor-
sally and more diffuse ventrally ( montanus Sal-
vin 1871:414). There are no locality records of
either H. clysonymus or H. hortense (No. 37)
from Nicaragua so the distribution of the two
species (?) seems discontinuous.
Specific Characters: Neither the male geni-
talia (Text-fig. 66), the hindwing androconia
(Text-fig. 106) nor the basal spots (Text-fig.
133) provide diagnostic specific characters, but
the complex taken as a whole, together with the
female abdominal processes (as Text-fig. 167),
will distinguish the species from all others ex-
cept H. hortense from which it may be separated
by its smaller and more regular wing shape.
37. Heliconius hortense Guerin-Meneville
1829-38:469
Map 22; Text-figs. 65, 107, 134, 167
This species is known only from Mexico,
British Honduras, Guatemala and Salvador and
is one of the largest Heliconius, with a wingspan
of about 100 mm. It has an unusually saturni-
form wing shape with pronounced scallops be-
tween the hindwing vein endings, but is in color
and pattern similar to H. clysonymus, with the
exception that the yellow forewing band is cen-
tered over the apex of the discal cell midway
between positions A and B.
Specific Characters: Neither the male geni-
tal valves (Text-fig. 65), the hindwing andro-
conia (Text-fig. 107) nor the basal spots (Text-
fig. 134) provide good characters, but taken
together with the curved female abdominal pro-
cesses (Text-fig. 167) they distinguish this spe-
cies from all others with the exception of H.
clysonymus from which it may be separated by
the larger size and special wing shape.
THE CHARITON lUS GROUP
Group features are the absence of signa on
the bursa copulatrix (Text-fig. 28), the sparse
distribution of androconia only on hindwing
veins Sc + R1 and Rs and on the membrane
around one or both of them (Text-figs. 109, 111-
118), the highly unequal lengths of the parony-
chial processes (Text-fig. 21), the rounded shape
of the male genital valves (Text-figs. 64, 67-74)
and the lack of terminal denticles, the presence
of conspicuous basal spots (Text-figs. 137-147)
and the very squat female abdominal processes
as in Text-fig. 172.
1965]
Emsley: Speciation in Heliconius
217
38. Heliconius charitonius
(Linnaeus 17 67 :7 57)
Map 21; Text-figs. 64, 109, 137
This is the most northerly ranging of all the
species of Heliconius, for in warmer years it
reaches California on the west coast of North
America and South Carolina on the east, and
even in abnormally cold years it can be expected
to survive north of the Mexican border and in
Florida. The geographic variation in this species
has been studied in detail by Comstock & Brown
(1950) and barely distinct races have been de-
scribed from Florida ( tuckeri Comstock &
Brown 1950:15), Mexico ( vazquezae Comstock
& Brown 1950:16), Cuba ( ramsdeni C. & B.
1950:14), Jamaica ( simulator Rober 1921:4),
Hispaniola ( churchi C. & B. 1950:14), Puerto
Rico and the Virgin Islands (charitonius) , St.
Kitts Antigua and Montserrat ( punctatus Hall
1936:276), and northern Colombia ( bassleri
C. & B. 1950:16). In southwestern Ecuador
and northwestern Peru the form peruvianus C.
& R. Felder 1859:396 is well differentiated by
the distal reduction of the forewing line along
Culb and the lengths of the fore wing bands,
which are white, and by the less elongate and
more rounded wing shape.
The ground color is a non-iridescent dark
brown with a yellow line over the forewing
cubitus which is deflexed posteriorly along the
anterior margin of Cu 1 b, a pair of oblique yel-
low bands in positions B and D and a red costal
spot. On the hindwing there is a yellow bar in
position II, a row of small spots in positions IV
and V, and on the ventral surface there is a
yellow costal streak, a brown marking at the
distal extremity of the bar III position and red
basal spots as in Text-fig. 137. The basal spots
are visible dorsally and include a pair on hind-
wing veins 1A and 2A. The wings are elongate
and have a span of about 85 mm.
Specific Characters: Neither the male geni-
tal valves (Text-fig. 64), the hindwing andro-
conial distribution (Text-fig. 109) nor the fe-
male abdominal processes (Text-fig. 172) are
diagnostic, but these characters taken with the
color pattern and the basal spot complex (Text-
fig. 137) are definitive.
39. Heliconius ricini (Linnaeus 1758:466)
Map 22; Text-figs. 67, 111, 139
This butterfly, with a wingspan of 65 mm,
looks superficially like a small H. clysonymus,
but the yellow forewing band is more proxi-
mal (A), there is a distal yellow band in position
D and a yellow line over both surfaces of the
cubitus stem. The hindwing has a dorsal bar over
coalesced positions I + II + III, a group of basal
spots, some of which are expressed dorsally
(Text-fig. 139), and a single red spot between
the veins 1A and 2A. There is a red costal spot
on the forewing, a yellow costal streak on the
hindwing and faint paired intervenal white
streaks emanating from submarginal white dots.
It is relatively constant throughout its range,
which extends from Caracas in Venezuela
through the Guianas into the Lower Amazon as
far as Ceara on the Brazilian coast. The form
insulanus Stichel 1909:179 from Venezuela and
Trinidad seems to differ from typical ricini only
in having been caught fresh before the red of the
hindwing bar had faded in sunlight. There are
no other sympatric species of Heliconius with a
similar color pattern.
Specific Characters: The male genital
valves are relatively small and without special
features (Text-fig. 67) and they cannot be dis-
tinguished from those of H. demeter or H. sarae.
The hindwing androconia are sparse (Text-fig.
Ill), the basal spot complex is distinctive (Text-
fig. 139) and the color pattern is clearly recog-
nizable.
40. Heliconius demeter Staudinger 1896:310
Map 2; Text-figs. 68, 112, 138
This species is known by comparatively few
specimens from widely separated localities in the
lower-middle Amazon, but such individuals as
are known conform to the trends in pattern no-
ticed in all the other dennis-rayed species.
In the Guianas eueidius Oberthiir 1916:37
(= egeriformis Joicey & Kaye 1916:430 = auto-
matius Oberthiir 1925:81) has a broken yellow
band together with dennis (Text-fig. 5) and an
erato- type ray pattern (Text-fig. 6) which bears
dorsally a basal bar in position I. In more west-
ern localities the forewing band becomes com-
pact, rectangular and distal to the discal cell
(demeter = bouqueti Noldner 1901:7).
The minor characters are a yellow forewing
costal spot, a yellow hindwing costal streak, three
red basal spots (Text -fig. 138), and a ventral
single row of paired white submarginal dots. The
light head markings are all white and the wing-
span is approximately 70 mm.
Specific Characters: The small male genital
valves have no distinctive features (Text-fig. 68) ;
the androconia are sparse (Text-fig. 112) but the
forewing costal spot is yellow.
41. Heliconius sarae (Fabricius 1793:167)
Map 24; Text-figs. 69, 113, 142
Heliconius sarae is a very widely distributed
yellow and blue butterfly which, though rela-
218
Zoologica: New York Zoological Society
[50: 14
tively uniform, has differentiated into recogniz-
able geographic races.
In Central America, and extending into north-
ern Colombia and Venezuela, the typical sarae
has a pair of yellow forewing bands in positions
A and D (Text-fig. 11), the proximal of which
is long and narrow, an intervenal white fringe
around the posterior border of the hindwing, and
one or two red spots on the ventral surface of
the hindwing in addition to the group of four
basal spots. The forewing costal spot is red as is
the comma-shaped hindwing costal streak (Text-
fig. 142) and there is a ventral yellow line along
the forewing radius. The wingspan is about 70
mm.
In Panama there is a dichromatic form ( then -
delus Hewitson 1874:224) which has a broad
yellow cream or white posterior border to the
hindwing which is composed of adpressed pairs
of short intervenal streaks in position IV. In this
form the peripheral white scales are lacking.
Throughout Central America there are forms of
sarae in which the inner forewing band is partly
white (veraepacis Bates 1864:57).
Where the species extends down the western
side of the Andes, the forewing band is shorter
and rectangular and the margin of the hindwing
in position V is narrowly pure white ( sprucei
Bates 1864:57).
East of the eastern Cordilleras of Colombia
and extending widely over the Amazon basin,
the long narrow inner band of sarae becomes
short, broad and oval and the number of post-
discal ventral hindwing spots increases from one
or two to four or five ( thamar (Hiibner 1806-
19) ) . Intermediate forewing band conditions oc-
cur in the Magdalena Valley, central Colombia
and Venezuela ( magdalenae Bates 1864:57),
together with specimens in which the discal band
is reduced and divided into a pair of spots ( lili-
anae LeMoult), or in which the distal band
is absent ( brevimaculatus Staudinger 1896:
292). Rare specimens are also known from this
area in which the forewing spots are ochreous
(aurentiacus) or white instead of yellow (albi-
maculatus Staudinger 1896: 292; albulus Riffarth
1900:208). White-banded forms also occur in
the Guianas (albineus Riffarth 1899).
Around the coast of Brazil the yellow discal
forewing band is broad and rectangular (apseu-
des ( Hiibner 1816:13)) with four to seven post-
discal red ventral hindwing spots (Text-fig. 142),
so there is a north-to-south cline in the develop-
ment of these spots with the maximum of two in
Central America rising to five in eastern Co-
lombia and to seven in southeastern Brazil.
It is interesting to notice that the variation in
the shape of the forewing band in sarae matches,
or is matched by, that of the sympatric forms of
H. wallacei, though it is doubtful if this is of
mimetic significance.
Specific Characters: The small male genital
valves are without distinctive features (Text-fig.
69), the androconia are concentrated on the
veins (Text-fig. 113), the anterior red costal spot
is small and rounded (Text-fig. 142) in contrast
with that of H. leucadius.
42. Heliconius leucadius Bates 1862:556
Map 25; Text-figs. 70, 114, 141
This species occurs sympatrically with H.
sarae thamar over the middle Amazon (and per-
haps lower) and along the foothills of the eastern
Andes; in appearance it is very similar but it can
be separated on the shape of the most anterior
basal spot (Text-fig. 141). The typical form
(leucadius) has a fine intervenal white fringe on
the posterior border of the hindwing but there
is a dichromatic form which has short coalesced
pairs of intervenal white streaks around the hind-
wing ( pseudorheus Staudinger 1896:291). The
two forms seem fully sympatric. The minor char-
acters are similar to those of H. sarae but H. leu-
cadius is a little larger (80 mm.) .
Specific Characters: The male genital
valves (Text-fig. 70) and androconial distribu-
tion (Text-fig. 114) hardly contrast with H. sarae
and reliance has to be placed on the shape of the
anterior basal spot which in H. leucadius is elon-
gate. Though probably not infallibly, leucadius
can be distinguished from sarae dorsally by the
failure of the discal forewing band to cross Culb
in leucadius.
43. Heliconius hygianus Hewitson 1867
Map 11; Text-figs. 71, 115, 143
This species is superficially similar to H. cly-
sonymus but differs considerably in points of
detail. The ground color is dark brown with a
narrow discal yellow forewing band in position
A and a small rounded yellow band in position E
(Text-fig. 11). There is a dorsal and ventral fore-
wing yellow line over the stem of the cubitus, a
red forewing costal spot, a red hindwing costal
streak enclosed by the recurrent humeral branch
of the subcosta, and a group of red basal spots
(Text-fig. 143). The hindwing also has a broad
dorsal and ventral orange bar in position II, but
is without trace of white on the margins of the
wings.
H. hygianus is known by a small number of
specimens taken from the western Ecuadorian
Andes at altitudes between 500 and 1 ,000 meters.
Specific Characters: The male genital
valves (Text-fig. 71) and androconial distribu-
1965]
Emsley: Speciation in Heliconius
219
tion are not good characters within the group,
so reliance has to be placed on the alary color
pattern.
44. Heliconius cintiochus (Linnaeus 1767 : 1068)
Map 26; Text-figs. 73, 117, 144
H. antiochus extends from the Magdalena
Valley and eastern cordilleras of Colombia
through Venezuela, the Guianas and along the
Amazon to the 400-meter level of its main trib-
utaries at the foothills of the Andes. Though
it could be expected to occur in Trinidad, there
are no authentic records of it having done so.
The typical form (antiochus ( Linnaeus 1767:
1068)) occurs over the whole range of the species
except in the Magdalena Valley, though it is un-
common in Venezuela and eastern Colombia.
It is a dark, slightly iridescent, blue above, with
a pair of entire narrow white forewing bands in
positions A and D (Text-fig. 11), a forewing
line over both surfaces of the cubitus (though it
is absent dorsally in albus Riffarth 1900:208)
and along the ventral surface of the radius (Text-
fig. 3) . In the lower Amazon and Guianian areas
the inner forewing band may be divided (zobe-
ide Butler 1869:18). Commonly in eastern
Colombia and always in the Magdalena Valley,
the forewing bands are yellow and again either
entire (araneus (Fabricius 1793 : 168)) or divided
(ocannensis Stichel & Riffarth 1905:181).
From a restricted locality on the border be-
tween Venezuela and British Guiana, there are
a small number of specimens known (salvinii
Dewitz 1877:86) in which, in addition to the
typical characters, there is a broad dorsal and
ventral hindwing yellow bar in position II. Some
specimens are known from neighboring locali-
ties in which there is a faint scattering of yellow
scales in the hindwing dorsal bar position and a
slight differentiation of the ventral bar area.
These may represent a heterozygous yellow bar
condition similar to that noticed in H. erato and
H. melpomene from Colombia (Emsley, 1964).
In all specimens the frons is white but the
remaining head markings are yellow. The fore-
wing costal spot is composed of scattered red
or yellow scales or both, the hindwing costal
streak is comma-shaped and red and the basal
spots form a complex which is similar to that
of H. sapho (Text-figs. 144 and 145) . Specimens
from Colombia are larger (85-90 mm.) than
those from the Amazon (75-85 mm.).
Specific Characters: The male genital
valves are thickened postero-ventrally (Text-
fig. 73), there are no androconia on the mem-
brane around Rs (Text-fig. 117) and the basal
spots are as Text-fig. 144, all of which are char-
acters common also to H. sapho and H. hewit-
soni, so specific distinction has to be based on
color pattern.
45. Heliconius sapho (Drury 1782:54)
Map 25; Text-figs. 72, 116, 145, 147
This species is variable in ground color, fore-
wing band pattern and in the development of
the light border to the hindwing. The charac-
ters which are reasonably constant include the
hindwing red basal spots and red costal streak
complex (Text-fig. 145) and red forewing costal
spot, so in order to describe the principal forms
the characters which undergo modification will
be treated separately.
The forewing band and hindwing light border
are each independantly modified. From Hon-
duras to Costa Rica the forewing band of leuce
Doubleday 1847:102 is white and rectangular
over positions A to D but with incisions on the
anterior and posterior margins and with a distal-
ly convex periphery. Between southern Costa
Rica and the valleys of northern Colombia, the
band becomes more restricted and distally trun-
cate but still entire (sapho). This band type per-
sists polychromatically in northern Colombia with
the semidivided band of eleusinus Staudinger
1885-88:7, which is itself a transition towards
the fully divided double yellow band (positions
A and D) of the sympatric eleuchius Hewitson
1854. Further south, on the western side of the
Andes as far as southwest Ecuador, the double
yellow divided band persists alone in primularis
Butler 1869:18. The form deflavus Joicey &
Kaye 1917:93 is an aberration of primularis in
which the hindwing border is very faint. The
form ceres Oberthiir 1920a: 30 has not been
seen but it is probably a minor variation of
eleusinus.
The hindwing border is narrow and white in
position V from Honduras to Costa Rica (leuce),
but broadens in sapho from Costa Rica and
Panama to the very broad white border of
eleuchius (positions IV + V). The narrow
border seen in leuce persists in Panama and
northern Colombia in eleusinus but the only
form known from western Colombia and west-
ern Ecuador is the very broad yellow and/or
white border of primularis in positions III + IV
+ V.
On the eastern side of the Andes between
central Colombia and northern Peru, congener
Weymer 1890b: 117 has a pair of yellow fore-
wing bands (positions A and D) and a medium
blue iridescent ground color without any hind-
wing border except white intervenal fringing
scales. The anterior red basal spot is smaller
than in typical sapho (Text-figs. 145, 147).
Specific Characters: The male genital
220
Zoologica: New York Zoological Society
[50: 14
valves are thickened postero-ventrally (Text-
fig. 72), there are no androconia around Rs
(Text-fig. 116) and the basal spots are as Text-
fig. 145, but as none of these characters differ-
entiates this species from either H. antiochus or
H. hewitsoni, reliance has to be placed on color
pattern.
46. Heliconius hewitsoni Staudinger 1875:98
Map 10; Text-figs. 74, 118, 146
This butterfly is exceptionally similar to H.
pachinus with which it is sympatric. It has a
pair of yellow forewing bands in positions A
and E on a scarcely iridescent dark blue ground
color, and has a broad yellow bar on the hind-
wing in position IV. The dorsal pattern is ex-
pressed ventrally together with a yellow fore-
wing line along the radius, a red costal spot, a
comma-shaped red costal streak on the hind-
wing and a group of red basal spots (Text-fig.
146).
The localities from which hewitsoni are known
are Sevilla Island, Parida Island, Chiriqui Vol-
cano, Bugaba, Lino (which are all in Panama)
and Pozoazul and other unspecified localities
in Costa Rica. It has been suggested by Seitz
(1913) and others that this is a high altitude
form of H. sapho but the data do not support
this view.
Specific Characters: The male genital
valves have a postero-ventral thickening (Text-
fig. 74), there are no androconia on the mem-
brane around Rs (Text-fig. 118), the basal spots
are as in Text -fig. 146, but none of these char-
acters are diagnostic, so reliance has to be placed
on color pattern. It may be distinguished from
H. pachinus by the more precise boundaries and
proximal position of the forewing bands, and
by the more elongate shape of the basal spot in
the angle between Sc 4- R1 and Rs (Text-figs.
146 and 128). All the basal spots in pachinus
have more diffuse edges then in hewitsoni.
NOTE ON MAPS
On the 26 maps that follow, the black areas
are where no Heliconius are known to occur,
as judged by museum specimens. It seems likely
that the distribution of Heliconius is more exten-
sive along the river valleys of the Brazilian high-
lands than is shown on the maps.
Map 1
1965]
Emsley: Speciation in Heliconius
221
Map 2
Map 3
222 Zoologica: New York Zoological Society [50: 14
Map 4
Map 5
1965]
Emsley: Speciation in Heliconius
223
Map 6
Map 7
224
Zoologica: New York Zoological Society
[50: 14
1965]
Emsley: Specialion in Heliconius
225
Map 11
226
Zoologica: New York Zoological Society
[50: 14
Map 12
Map 13
1965]
Emsley: Speciation in Heliconius
227
Map 14
Map 15
228
Zoologica: New York Zoological Society
[50: 14
Map 16
narceus etc.
Heliconius ethiUus
^metalilis, ethillus etc.
eucomus etc.
fortunatus etc.
^3-
fornannus
zuleikus ^
melicertus etc.
Ithacus etc.
Map 17
1965]
Emsley: Speciation in Heliconius
229
euryas
Heliconius melpamene
- 0. ..
heunppus
melpomene
rosinus
vulcanus
thelxiope etc.
cytherus
timaretus etc
plesseni /
ecuadorensis ' /^H
amaryllis ' /
xenocleus '
euryades
bescke
Map 18
Map 19
Zoologica: New York Zoological Society
[50: 14
Map 20
Map 21
1965]
Emsley: Speciation in Heliconius
231
H. ricini
Heliconius clysonymus
H. hortense
H. ricini
H. hortense
H.c. montanus
H. clysonymus
Map 22
erato
venus
Heliconius erato
chestertoni ^
colombmus
adonus
petiveranus
cyrbius
notabilis/ / Wfl
etylus ' yn H
favorinus '
microcleus
amphitrite
phyllis
Map 23
232
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[50: 14
Heliconius sarae
thamar
apseudes
Map 24
Map 25
1965]
Emsley: Speciation in Heliconius
233
Map 26
Taxonomic References
Apolinar, M.
1926. Bot Soc. colomb. Ci. nat. Bogota, 15.
1927. Bot. Soc. colomb. Ci. nat. Bogota, 16.
Clerk, ?
1764. leones, sect. 2.
Comstock, W. P. & Brown, F. M.
1950. Am. Mus. Novit., No. 1467.
Bates, H. W.
1862. Trans. Linn. Soc. Lond., 23.
1863. Proc. zool. Soc. Lond.
1864. Entomologist’s mon. Mag., 1.
1866. Entomologist’s mon. Mag., 3.
1867. Trans. R. ent. Soc. Lond., (3), 5.
Billberg, ?
1820. Enum. Ins. in Mus. Billberg.
Boisduval, J. A.
1870. Consid. Lep. Guatemala. Rennes.
Boisduval, J. A. & LeConte, J. E.
1836. Hist. gen. Lep. Chen. Amer., Sept.
Boullet, E. & LeCerf, F.
1909. Bull. Mus. Paris., 15.
1910. Bull. Mus. Paris., 16.
Bryk, F.
1953. Ark. zoo. (n. ser.), 5, Stockholm.
Butler, A. G.
1869. Ann. Mag. nat. Hist., (4), 3.
1873. Cistula Ent., 7.
1875. Ann. Mag. nat. Hist., (4), 15.
Butler, A. G. & Druce, H.
1872. Entomologist’s mon. Mag., 9.
Cramer, P.
1775-76. Pap. exot., 1.
1777. Pap. exot., 2.
1779. Pap. exot., 3.
1780-82. Pap. exot., 4.
Dewitz, H.
1877. Mt. Munch ent. Ver., 1.
Doubleday, E.
1847-48. Gen. diurn. Lep., 1.
Druce, H.
1874. Trans. R. ent. Soc. Lond.
1876. Proc. zool. Soc. Lond.
Drury, ?
1782. Nat. Hist., 3.
Erichson, ?
1848. Schomburgk, Guiana, 3.
Fabricius, J. C.
1775a. Gen. Ins.
1775b. Syst. Ent.
1793. Syst. Ent., 3.
Fassl, A. H.
1912. Ent. Rdsch., 29.
234
Zoologica: New York Zoological Society
[50: 14
Felder, C. & R.
1859. Wein. Ent. Monatschr., 3.
1861. Wein. Ent. Monatschr., 5.
1862. Wein. Ent. Monatschr., 6.
1865. Reise Novara, 2.
Fruhstorfer, H.
1910. Ent. Z. Stuttgart.
Geyer, ?
1832. Zutr. exot. Schmett., 4.
Godart, J. B.
1819. Enc. meth., 9.
Godman, F. D. & Salvin, O.
1881. Biol. Centr. Amer., Lep. Rhop., 1.
Goeze, ?
1779. Ent. Beytr., 3.
Grose Smith & Kirby, W. F.
1892. Rhop. Exot., 1.
Guerin-Meneville
1829-38. Iconogr. Regn., 3, Ins.
Hall, A.
1921. Entomologist, 54.
1930. Entomologist, 63.
1936. Entomologist, 69.
Hemming, F.
1933. Entomologist, 66.
Hewitson, W. C.
1852-54. Exot. Butt., 1.
1857. Exot. Butt., 2.
1861. Int. exot., 1.
1863. Proc. zool. Soc. Lond.
1864. Trans. R. ent. Soc. Lond., (3), 2.
1867a. Exot. Butt., 4.
1867b. Trans. R. ent. Soc. Lond., (3), 5.
1869a. Trans. R. ent. Soc. Lond., (3), 7.
1869b. Equat. Lep.
1872. Entomologist’s mon. Mag., 9.
1873. Exot. Butt., 5.
1874. Entomologist’s mon. Mag., 10.
1875. Entomologist’s mon. Mag., 11.
Hayward, K. J.
1931. Rev. Soc. ent. Argent., 4.
1952. Acta zool. Lilloana, 10.
Hoffman, C. C.
1940. Ann. Inst. Biol. Mexico, 11.
Hubner, J.
1806-19. Exot. Schmett., 1.
1816-19. Verz. bekannt. Schmett.
1825. Samml. Exot. Schmett., 2.
Joicey, J. J. & Kaye, W. T.
1916. Trans. R. ent. Soc. Lond.
1917. Ann. Mag. nat. Hist., (8), 20.
Joicey, J. J. & Talbot, G.
1925. Ann. Mag. nat. Hist., (9), 16.
Kaye, W. J.
1906. Entomologist, 39.
1913. Proc. R. ent. Soc. Lond.
1916a. Entomologist’s Rec. J. Var., 28.
1916b. Entomologist, 49.
1919. Ann. Mag. nat. Hist., (8), 3.
Kluk, ?
1802. Zwierz. Hist. nat. Pocz. Gospod., 4.
Kotsch, H.
1936. Ent. Rdsch., 53.
Kruger, R.
1925. Dt. ent. Z., 39.
1933. Int. ent. Z., 27.
Kirby, W. F.
1900. Exot. Schmett Hubner.
Lathy, P. I.
1906. Proc. zool. Soc. Lond.
Latreille, ?
1817. in: Humbolt and Bonpland, Voy. Amer.
2.
Lichy, R.
1960. Rev. Fac. Agron. Univ. cent. Venez., 2,
(3). Maracay.
Linnaeus, C.
1758. Syst. nat., ed. 10.
1767. Syst. nat., ed. 12.
1771. Mant. Plant., II.
Menetries, ?
1857. Lep. Ac. St. Petersb., 2.
Michael, O.
1926. Ent. z. Frankfurt., 39.
Neustetter, H.
1907. Verh. zool.-bot. Ges. Wien.
1908. Verh. zool.-bot. Ges. Wien.
1912. Fauna exot., 2.
1913. Verh. zool.-bot. Ges. Wien.
1916. in: Seitz, Grobschmett., 5.
1924. Trans. R. ent. Soc. Lond.
1925. Ost. Ent. Ver., 10.
1928. Int. ent. Z., 22.
1929. in: Strand, Lepidopterorum Catalogus,
(36).
1931. Int. ent. Z., 25.
1932. Ost. Ent. Ver., 17.
1938. Ent. Rdsch., 55.
Niepelt, W.
1923. Int. ent. Z., 17.
Nolder, ?
1901. Berl. ent. Z., 46.
Oberthur, C.
1902. Etudes d’ Ent., 21.
1916. Et. Lep. Comp., 12.
1920. Et. Lep. Comp., 17.
1923. Et. Lep. Comp., 20.
1925. Et. Lep. Comp., 22.
Paclt, J.
1955. Beitr. ent., 5.
Reakirt, T.
1866. Acad. nat. Sci. Philad.
Riffarth, H.
1899. Berl. ent. Z., 44.
1900. Berl. ent. Z., 45.
1901. Berl. ent. Z., 46.
1906. Insektenborse, Leipzig, 23.
1907. Dt. ent. Z.
1908. Berl. ent. Z., 53.
1965]
Emsley: Speciation in Heliconius
235
Rober, J.
1923. Ent. mitt., 72, Berlin.
1927. Int. ent. Z., 21.
Salvin.O.
1871. Ann. Mag. nat. Hist., (4), 7.
Salvin, O. & Godman, F. D.
1868. Ann. Mag. nat. Hist., (4), 2.
1877. Proc. zool. Soc. Lond.
Seitz, A.
1913. Grobschmett, 5.
1916. Grobschmett, with appendix, 5.
Srnka, A.
1885. Berl. ent. Z„ 29.
Staudinger, O.
1875. Verh. zool.-bot. Ges. Wien., 25.
1876. Verh. zool.-bot. Ges. Wien., 25.
1882. Proc. zool. Soc. Lond.
1885-88. Exot. Schmett., 1.
1896. Dt. ent. Z., Lep., 9.
1900. Dt. ent. Z., Lep., 12.
Stichel, H.
1903. Berl. ent. Z„ 48.
1906. Gen. Ins., Wytsman, 37.
1907. Gen. Ins., fasc. 63, Wytsman.
1909. Societas ent., 23.
1912. Int. ent. Z.
1919a. Zeit. f. wiss. Ins. Biolog.
1919b. Neue Beitrage zur Syst. Insektenk., 1.
1923. Dt. ent. Z.
Stichel, H. & Riffarth, H.
1905. Das Tierreich, Heliconiidae, 22.
Strand, E.
1912. Archiv. f. Naturgesch.
SWAINSON, W.
1827. Phil. Mag. (n. ser.), 1.
Talbot, G.
1932. Bull. Hill Mus., 4.
Weymer, G.
1875. Stettin ent. Ztg., 36.
1884. Stettin ent. Ztg., 45.
1890a. Stettin ent. Ztg., 51.
1890b. Lep. Reise Stiibel.
1893. Dt. ent. Z., Lep. 6.
1896. Dt. ent. Z., Lep. 9.
1906. Dt. ent. Z„ Lep. 19.
1912. Ent. Rdsch., 29.
ZlKAN, I. F.
1937. Ent. Rdsch., 54.
IV. Summary of Evidence for the
Systematic Presentation
Previous studies on the subfamily have re-
vealed (Emsley, 1963) that there are a consider-
able number of morphological characters of
value in establishing systematic relationships, but
concern was then principally with different gen-
era, each containing only a small number of
clearly defined species. Though the anatomy of
the imagines has been completely re-examined,
the only new characters that have been found to
be of use are the minor components of the alary
color-pattern. The major components of the col-
or-pattern have been avoided as far as possible
to guard against misjudgement over convergent
similarities due to Batesian or Mullerian mim-
icry. The relatively inconspicuous features like
the forewing costal spot, the hindwing costal
streak and the basal spot complex are less likely
to have been influenced by such effects or at least
have remained more conservative and hence of
greater value to the systematist.
The definition of Heliconiinae is reassuringly
clearcut, for no other Papilionoidea have the re-
current humeral branch of the hindwing sub-
costa unforked (Text-fig. 2) , have androconia on
the wing veins of males and have capitate pro-
cesses developed from the posterior margin of
the eighth abdominal segment of females (Text-
figs. 161-172).
Unfortunately, few criteria have been found
which will enable the genus to be divided into
larger units than the thirteen species-groups pro-
posed here. The shape of the duct from the
spermathecal diverticulum (Text-fig. 18) and
the reduced number of female protarsal articles
(Text-fig. 14) separates the genus into the sub-
genera Eueides and Heliconius. Within Eueides
occur typical Heliconius characters like the de-
velopment of the red basal spots (H. lybius
lybius) and the presence of androconia on the
membrane around Sc + R1 and Rs (H. tales, H.
lybius) which lessen the clarity of the taxonomic
division.
The evidence for the assertion that the Eueides
species are the more primitive is based on the ex-
clusive restriction of the androconia to the veins
of the wings and on the narrowness of the duct
from the spermathecal diverticulum, both char-
acters which are common to all the other genera
of Heliconiinae. Corroborating evidence is the
acute angle through which the signa of the bursa
copulatrix are curved, which is again a heliconi-
ine character. Less convincing but worth noting
is the occurrence of a denticulate zone along the
interior surface of the dorsal portion of the male
genital valve in all Eueides species (Text-figs.
32-39), in most of the other genera but in few
of the subgenus Heliconius (Text-figs. 40-74)
(on other criteria those species of Heliconius
which have this extensive denticulate zone are
considered among the most primitive).
The unity of Eueides is supported by a tend-
ancy to asymmetry in the signa which is at its
maximum in H. alipherus (Text-figs. 24, 25),
is strong in H. tales (Text-figs. 153, 154) and
H. lybius (Text-figs. 151, 152) and is detectable
236
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Text-figs. 32-39. Inner aspect of left genital valves of male Heliconius. 32, H. alipherus; 33, H. vibilius
or H. pavanus; 34, H. edias; 35, H. lineatus ; 36, H. eanes; 37, H. isabellae; 38, H. lybius; 39, H. tales.
throughout the subgenus. There is also a ten-
dancy for the pretarsal paronychia to be more
coarsely spinose and more broad apically than
in the subgenus Heliconius (Text-figs. 19-23).
The similarity between H. alipherus and Co-
laenis iulia, both in the hand and in flight, is
most striking and, in view of the correlated vari-
ation in their appearance in the northwestern
part of their grossly similar and extensive range,
it is tempting to postulate a mimetic association.
However, the occurrence of a similar pattern in
H. lybius and H. lineatus allows the possibility
that the pattern is a relic. In fact, it is not difficult
to imagine the derivation of the patterns seen in
H. natteri, H. hecalasius, H. longarenus and H.
vibilius from that of such an ancestor. The red
basal spots, which are highly developed in some
species of Heliconius, and are present in most,
are present also in Colaenis iulia, Agraulis vanil-
lae and in an orange form in Philaethria dido, so
these too may be an ancestral character.
The evolutionary scheme presented here has
been based on the premise that the presence of
androconia on many fore or hindwing veins is
a primitive character. This premise has been ac-
cepted because Philaethria, Dione and Podo -
tricha have androconia on nearly all the fore and
hindwing veins, Agraulis and Dryadula have
them on many hindwing veins and in Colaenis
they are present on up to six forewing veins and
on hindwing veins Sc + R1 and Rs, as in all Heli-
conius. If the discal cell of Colaenis was closed
by the cross-vein M2-M3, then the only charac-
ter which would be inconsistent with it being
1965]
Emsley: Speciation in Heliconius
237
Text-figs. 40-44. Inner aspect of left genital valves of male Heliconius. 40, H. egerius egerius; 41, H.
wallacei; 42, H. burneyi; 43, H. egerius astreus; 44, H. hierax.
placed in Heliconius ( Eueides ) would be the five-
articled female foretarsus.
Within Eueides, H. alipherus and H. edias
seem the most primitive on account of their more
extensive androconial distribution (forewing H.
edias , Text-fig. 98; hindwing H. alipherus, Text-
fig. 75). The signa of both these species are
broader than any other in Heliconius and similar
to that of Philaethria (Text-figs. 24, 25, 149 and
in Emsley 1963: fig. 124).
The male genital valves of H. vibilius, pava-
nus, eanes and lineatus are very like those of H.
edias (Text-figs. 33-36), but the androconial dis-
tribution is restricted to the hindwing veins Sc +
R1 and Rs (Text-figs. 76-77) and the signa are
more arcuate (Text-fig. 150). Straightness is
considered a primitive characteristic of the fe-
male abdominal processes, so no great impor-
tance is attached to this similarity in these species.
H. isabellae differs from the other members of
the vibilius group principally in the male genital
valves (Text-fig. 37) and in the details of the
androconial distribution (Text-fig. 78), so it is
deemed to be included. The male genitalia of this
group are not very different from those of H.
alipherus (Text-fig. 32) but on androconial dis-
tribution and asymmetry of the signa they must
remain distinct. No particular importance is at-
tached to the loss of the terminal spine on the
female foretarsus in H. alipherus (Text-fig. 15)
and H. pavanus as gross reduction of the fore-
tarsus is a feature of Eueides. A similar reduc-
tion was noticed in Dione and Agraulis (Emsley
1963:106). The reduction of the signa in pava-
238
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Text-figs. 45-51. Inner aspects of left genital valves of male Heliconius. 45, H. natteri; 46, H. melpomene;
47, H. cydno; 48, H. numatus; 49, H. ethillus or H. elevatus ; 50, H. atthis; 51, AT. aristionus.
nus (Text-fig. 148) is considered to be a speciali-
zation and perhaps illustrates the mode of loss
in some of the higher groups.
The two species H. tales and lybius have simi-
lar but distinctive genital valves (Text-figs. 38,
39) and are distinguished from all other Eueides
by the presence of androconia on the membrane
around the veins Sc + R1 and Rs. Their signa are
also more acute-angled and more slender than
any other species in the genus (Text-figs. 151-
154), and their female abdominal processes are
strongly curved (Text-fig. 169).
The subgenus Heliconius, which is character-
ized by the broad duct from the spermathecal
diverticulum (Text-fig. 16), the arrangement of
the androconia around the hindwing veins Sc +
R1 and Rs (Text-fig. 31) and the five-articled
female protarsus (Text-fig. 13), is divisible into
two classes on the presence or absence of signa
on the bursa copulatrix (Text-figs. 26, 28) . How-
ever, it is suggested that the loss of the signa has
occurred at least twice independently, once in
the natteri group and secondly in the mutual an-
cestor of the hecalasius and charitonius groups.
The signate groups of Heliconius sensu stricto
can be separated into groups on the shape of the
1965]
Emsley: Speciation in Heliconius
239
Text-figs. 52-57 . Inner aspect of left genital valves of male Heliconius. 52, H. godmani; 53, H. aoede;
54, H. metharme; 55, H. doris; 56, H. hecubus; 57, H. xanthocles.
signa (Text-figs. 148-160), but on its own this
character is of limited value for within groups
it has no recognizable specific features. The an-
droconial distribution (Text-figs. 81-118) shows
more variation within groups in that one or more
members usually has an extensive distribution.
The male genital valves have to be used with
discretion, for though most of the groups have
characteristically distinct shapes (Text-figs. 40-
74), within the groups only occasionally do they
provide valuable specific characters. The red
basal spots are widely distributed throughout the
subgenus and at least one member of each group
exhibits them and in some groups they are a
very conspicuous feature (Text-figs. 119-147).
No consistent variation was noticed in the female
foretarsi within the subgenus Heliconius but the
relative lengths of the paronychial processes are
different in some groups, the most noticeable
being the extreme reduction in the charitonius
group.
The natteri group, which contains only H. nat-
teri, forms a link between the two subgenera. It
is allied to Heliconius s.s. in the appearance of
the male genital valves (Text-figs. 45, 46-51),
yet the androconia though restricted to the hind-
wings are confined to the veins, as is typical of
Eueides (Text-fig. 81 ). As in most of the species
which are considered primitive, the female ab-
dominal processes are slender and straight. The
absence of signa is considered a loss, as signa
are of wide occurrence in the subfamily and
other Papilionoidea.
It does not seem possible to indicate which of
the groups containing hierax, godmani, wallacei,
doris, hecubus and numatus are the most primi-
tive as they all have members with and without
extensive venal androconia; nor does the shape
of the signa assist in this connection, as it has
already been noticed in Eueides that the differ-
ences between the signa of two species which are
closely related (pavanus and vibilius) can be as
great as that between two groups. However it
does seem that the hecalasius and charitonius
groups are more advanced, as they have termi-
nally reduced genital valves, no signa, no andro-
conia on forewing veins other than marginally
on 1A, and the hindwing androconia are sparse.
Though hierax is differentiated here as a sepa-
rate group on account of the unique signa (Text-
fig. 155) and androconial distribution (Text-fig.
82 ) , the male genital valves are similar in design,
though not in development, to those of the wal-
lacei group (Text-figs. 40-43), a similarity that
is also in evidence in the basal spot complex
(Text-figs. 121, 123-125). The female processes
are straight and slender (Text-fig. 161), which
is considered a primitive feature.
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Text-figs. 58-62. Inner aspect of left genital valves of male Heliconius. 58, H. hecalasius; 59, H. longare-
nus; 60, H. erato; 61, H. hermathenae; 62, H. himerus.
The wallacei group have affinities with both
hierax and the godmani group for there is in each
a tendency towards an arcuate signa (Text-fig.
157), and there is a similar tendency in aoede
(Text-fig. 85) and egerius (Text-fig. 88) for the
androconia to be dispersed over the anterior
membrane of the hindwing.
The godmani group are homogeneous, the gen-
ital valves are very similar (Text-figs. 52-54),
there is an unusually tubular spermatheca (Text-
fig. 17) , and the signum is reduced to a regularly
curved slender arc (Text-fig. 156). The main
variation is in the localization of the androconia
to the veins of the hindwing (Text -figs. 83-85)
which in godmani is reminiscent of natteri (Text-
fig. 81).
Heliconius doris is difficult to place, as outside
H. elevatus and the charitonius group it is the
only species that has red on the hindwing costal
streak, but the shape of the signa (Text-fig. 27)
is intermediate between that of the godmani and
wallacei groups and the male genital valves can
be allied most clearly with those of the wallacei
group (Text-fig. 55). Though the gross appear-
ance of the color-pattern is typical of many
species of Heliconius, non-red ray features are
unique (Text-figs. 7, 9) .
The two species H. hecubus and xanthocles,
though quite dissimilar in appearance, have al-
most identical male genital valves (Text-figs. 56,
57) which are distinguishable from those of all
other groups, though those of closest affinity
seem to belong to the wallacei and godmani
groups. The presence of androconia on the fore-
wing veins in hecubus (Text-fig. 99) is consid-
ered a primitive character and the differences in
the signa (Text-figs. 158, 159) suggests that these
two species have been distinct for a relatively
long time.
All the groups discussed so far have straight,
slender female abdominal processes and have
denticles along the greater part of the dorsal
component of the male genital valve, both of
which are characters which are considered to be
primitive in the genus. The only remaining sig-
nate group for discussion is the numatus group,
which is characterized by the restriction of denti-
cles on the male genital valves to the apex of the
dorsal component and the internal position of
the ventral component (Text-figs. 46-51). The
denticles at the base of the dorsal component in
melpomene (Text-fig. 46) and cydno (Text-fig.
47) may be a vestige of the ancestral distribution
which has persisted in the more primitive species.
The valves of the pairs of species elevatus and
ethillus (Text-fig. 51) and cydno and pachinus
(Text-fig. 47) cannot be distinguished and even
the valves of numatus (Text-fig. 48) and aristio-
nus (Text-fig. 51) can only be distinguished with
a series of each. Within the group the radius of
deflection of the signa varies, but in all species
the posterior arm is relatively long (Text-figs. 26,
160). H. numatus has androconia on many of
the fore and hindwing vein (Text-figs. 101, 92),
aristionus and elevatus have them on several
hindwing veins and forewing veins 1A, but mel-
1965]
Emsley: Speciation in Heliconius
241
Text-figs. 63-74. Inner aspects of left genital valves of male Heliconius. 63, H. telesiphe; 64, H. chari-
tonius; 65, H. hortense; 66, H. clysonymus; 67, H. ricini; 68, H. demeter; 69, H. sarae; 70, H . leucad-
ius; 71, H. hygianus; 72, H. sapho; 73, H. antiochus; 74, H. hewitsoni.
pomene, ethillus, atthis, hecale, cydno and pachi-
nus have them only on the veins Sc + R1 and Rs
(Text-figs. 94-97) of the hindwing and forewing
vein 1A. The development of the red basal spots
varies from complete absence without trace in
cydno, hecale and numatus, through the reten-
tion of a single spot in atthis, aristionus, ethillus
and elevatus (Text-figs. 129, 130), to reasonably
complete development in melpomene (Text-fig.
131 ) . The condition in pachinus is unlike that of
any other species and is discussed in the next
section (Text-fig. 128). The similarity between
the androconial distribution of wallacei and nu-
matus is attributed to the persistence of a primi-
tive condition and as in the other groups there
is a trend towards an even but dense distribution
of androconia around the hindwing veins Sc +
R1 and Rs.
The non-signate groups, other than natteri,
are the hecalasius and charitonius groups which
are assumed to have evolved from a common
non-signate ancestor.
The hecalasius group contains hecalasius, hi-
inerus, telesiphe and hermathenae which by vir-
242
Zoological New York Zoological Society
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Text-figs. 75-88. Dorsal view of left hindwings of male Heliconius to illustrate the variation in the
distribution of androconia. 75, H. alipherus; 76, H. edias or H. vibilius; 77, H. eanes or H. lineatus; 78, H.
isabellae; 79, H. lybius; 80, H. tales; 81, H. natteri; 82, H. hierax; 83, H. godmani; 84, H. metharme;
85, H. aoede; 86, H. wallacei; 87, H. burneyi; 88, H. egerius. About twice natural size.
1965]
Emsley: Speciation in Heliconius
243
Text-figs. 89-97. Dorsal view of left hindwings of male Heliconius to illustrate the variation in distri-
bution of androconia. 89, H. doris, 90, H. hecubus; 91, H. xanthocles; 92, H. numatus; 93, H. aristionus
or H. elevatus; 94, H. ethillus; 95, H. atthis; 96, H. melpomene ; 97, H. cydno. About twice natural size.
tue of their unusually extensive androconial
distribution are considered more primitive than
erato, longarenus, clysonymus and hortense
(Text-figs. 102-108, 110). The genital valves of
male hecalasius (Text-fig. 58), longarenus (Text-
fig. 59), hermathenae (Text-fig. 61), erato (Text-
fig. 60) and himerus (Text-fig. 62) are basically
similar and have terminal denticles which are
absent from the valves of telesiphe (Text-fig. 63),
clysonymus (Text-fig. 66) and hortense (Text-
fig. 65). All the members of the group have basal
spots except hecalasius and longarenus (Text-
figs. 132-136, 140). The reduction of the andro-
conia on the media veins of the hindwings of
specimens of hecalasius from southern localities
opens up the possibility that longarenus, which
has none, is conspecific; otherwise they are mor-
phologically similar and in color-pattern not
basically different. The unexamined gynaesius
may be of assistance in this problem. Though
the red forewing band of hermathenae is con-
sidered of independent origin from that occur-
ring in erato, there is a similarity in the arrange-
ment of the supernumerary basal spots (Text-figs.
136, 140) which suggests a close relationship,
for the arrangement of the proximal basal spots
on the other species in the group is relatively
uniform (Text-figs. 132-136, 140).
The charitonius group is morphologically ex-
ceedingly uniform. The female processes are
short and squat (Text-fig. 172), the male genital
valves are almost indistinguishable (Text-figs.
64, 67-74) except for a tendency in antiochus,
sapho and hewitsoni for the lower limb to be
ventro-distally thickened (Text-figs. 70, 72-74).
The androconia are confined exclusively to the
hindwing veins Sc + R1 and Rs and narrowly to
the membrane around them (Text-figs. 111-1 15),
or in some cases (antiochus, sapho and hewitsoni)
not even on the membrane around Rs (Text-figs.
244
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Text-figs. 98-101. Dorsal view of left forewings of male Heliconius to show variation in androconial
distribution. 98, H. edias; 99, H. hecubus; 100, H. ethillus; 101, H. numatus. About twice natural size.
1 1 6- 1 1 8 ). A subdivision within the group can be
identified by the red hindwing costal streak, a
character known elsewhere in the genus only in
H. doris and H. elevatus; these species comprise
sarae, leucadius, hygianus, sapho, antiochus and
hewitsoni (Text-figs. 141-147). The remaining
species are charitonius, ricini and demeter which
are normal in that the hindwing costal streak is
yellow. H. demeter is unusual in that the fore-
wing costal spot is yellow too, a condition known
elsewhere in the subgenus only in H. egerius. H.
leucadius seems to occupy a position intermedi-
ate between the sapho sub-group and sarae and
hygianus (see Text-fig. 173).
V. Evolutionary Discussion
So far in this systematic study, a deliberate
attempt has been made to avoid using the more
obvious color-patterns of the wings, as it is likely
that there are similarities due to convergence.
However, when the color-patterns are consid-
ered in relation to geographic distribution, they
provide useful data.
The over-all range of the genus Heliconius can
be divided into five zones: Central America and
northern Colombia; western Ecuador and west-
ern Colombia; eastern Ecuador, Peru and Bolivia
above 850 meters; coastal Brazil; and the Ama-
zon basin. Before launching a hypothesis to ex-
plain the present diversity of the genus, an ac-
count must be given of the geographic history of
the relevant portions of the American continents.
Palaeogeographers are not in complete agree-
ment over the details of the continuity of the land
masses in the early Tertiary, but here the views
of Weeks (1947) and Lloyd (1963) have been
followed and the four maps (27-30) drawn from
their data. The geological evidence suggests that
the maximum distance between the continents
during the Upper Eocene was 650 miles (Map
28), but in the absence of fossils it is difficult to
estimate how much of a barrier this was to the
dispersal of mobile Papilionoidea. Though the
distance was greater than this in the Palaeocene
and Oligocene (Maps 27, 29), there were always
some islands which could have acted as stepping
stones.
The neotropical Heliconiinae seem the only
major subdivision of the Nymphalidae which are
confined to one zoogeographical region. Some
Australasian and Oriental genera have been ex-
amined, but no heliconiine characters have been
found. The restricted distribution could be due
either to all the non-neotropical representatives
having become extinct, which in view of the suc-
cess enjoyed in South America seems unlikely,
or the group could have evolved at a time when
it was too late to disperse laterally into the other
continents because of the low northern tempera-
tures.
The Lamaride revolution, which produced the
Rocky and Andean mountain chains, began in
1965]
Emsley: Speciation in Heliconius
245
Map 30
the Cretaceous and by the Eocene had elevated
the row of large islands seen in Map 27. This up-
lift changed the course of the drainage in South
America from the east-west direction of the
Palaeocene epoch (Map 27) to the northerly
outlet of the Oligocene (Map 29). The Guian-
ian and Brazilian mountains are not figured on
the maps, but they are known to have been a
dominant feature of the geography of the conti-
nent since the Pre-cambrian and have undoubt-
edly impeded the dispersal of Heliconius around
coastal Brazil.
The second main wave of Andean orogeny
occurred at the end of the Miocene and raised
the western continent to such an extent that the
drainage changed to that known today, with the
consequent silting up of the inland sea of the
early Miocene (Maps 29, 30). This period was
probably the critical phase in the evolution of
Heliconius, for there would have been the op-
portunity for the colonization of a new area of
land, and not just competitive incursion into a
territory already occupied by a well-established
flora and fauna. It may well have been a critical
phase in the evolution of Passiflora too, but there
is insufficient data to consider the interaction of
the larval foodplants at this stage of our knowl-
edge.
In the following hypothesis it is assumed that
the two subgenera of Heliconius were already dis-
tinct at the time of incursion into South America.
Within the more primitive subgenus Eueides the
stable species alipherus, lybius, lineatus and to
a lesser extent vibilius still exhibit the ancestral
color-pattern also retained by Colaenis iulia. Of
the species listed, only the Central American
lineatus is not widely distributed and it may be
a relic of the North American fauna which sur-
vived on the southern peninsula while the main
evolution of the genus was taking place in South
America.
The hypothesis assumes that the invasion of
South America took place during the Eocene
and Oligocene so that by the beginning of the
Miocene the main species groups had become
differentiated, and the whole of the continental
area that was ecologically suitable had been colo-
nized. The geography of South America at this
time, about 25 million years ago, is shown on
Map 29. The western peninsula was isolated by
-water on all sides except the south where the
mountains may or may not have acted as a bar-
rier. As the orogenic movements increased, the
fauna of the western slopes would still have been
isolated even after the establishment of land con-
tinuity to the east, but by mountains instead of
water. It is on these western slopes that we now
find the peculiar species atthis, godmani, longa-
renus and hygianus, each of which belongs to a
distinct species group. It is suggested that these
species are endemic.
The small number of species that have colo-
nized eastern Brazil is probably due to the nar-
row entrance to the coastal plane that lies be-
tween the Brazilian highlands and the sea. Only
H. natteri and pavanus are considered truly na-
tive.
In the northwestern part of South America
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Text-figs. 102-109. Dorsal view of left hindwings of male Heliconius to illustrate variation in the distri-
bution of androconia. 102, H. himerus; 103, H. hecalasius; 104, H. longarenus; 105, H. telesiphe; 106,
H. clysonymus; 107, H. hortense; 108, H. hermathenae; 109, H. charitonius. About twice natural size.
during the early Miocene there were a few large
islands which had been united in the Eocene. It
is suggested that it was on these islands that the
endemic fauna of northern Colombia originated,
some species of which have since extended their
range. These endemic species are edias, hecubus,
hecalasius, cydno, sapho, clysonymus and chari-
tonius. It is probably also from this center that
telesiphe spread southwards down the eastern
side of the Andes. The existence of cydno and
sapho stock material in this area in the Upper
Miocene could account for the present distribu-
tion of pachinus and hewitsoni, for it was about
this time that the Talamanca island first appeared
( Map 30) . If the precursors of cydno and sapho
had managed to colonize Talamanca in the Up-
per Miocene, there would have been time for
reproductive isolation to have occurred before
the parent species advanced up the elevated isth-
mus of Central America in the Pliocene. The
present distribution of both pachinus and hewit-
soni is at the southern extremity of the Tala-
manca ridge and the islands off-shore. If this is
correct, H. lybius lybioides may well have had a
similar origin, for it too is peculiar to the Chiri-
qui volcano and the immediate neighborhood.
Further work may show that it is specifically dis-
tinct from the closely related H. lybius olympius
which inhabits the surrounding areas of Central
America.
The two species hewitsoni and sapho are mor-
phologically almost identical, as are pachinus
and cydno. However, hewitsoni and pachinus are
very similar in color-pattern, and so are sapho
1965]
Emsley: Speciation in Heliconius
247
Text-figs. 110-118. Dorsal view of left hindwings of male Heliconius to illustrate variation in the distribu-
tion of androconia. 110, H. erato; 111, H. ricini; 112, H. demeter; 113, H. sarae; 114, H. leucadius;
115,//. hygianus; 116,//. sapho; 117, H. antiochus; 118, H. Iiewitsoni. About twice natural size.
and cydno. The relationships among these four
species are therefore of some interest. H. hewit-
soni has very large hindwing red basal spots and
belongs to a species-group in which they are al-
ways very conspicuous. H. pachinus also has
very large basal spots, but these are of a unique
character, and its closest relatives have either
very small spots or no spots at all (H. cydno). The
spots of pachinus do not conform to the pattern
which is common to all other species of Heli-
con ins, and the edges of the spots are of an ap-
pearance unknown elsewhere. It is suggested that
the red basal spots of pachinus are not homo-
logous with those of hewitsoni but have been
evolved from a non-spot ancestor such as cydno.
The remarkable similarity between these two
sympatric species suggests a mimetic relationship
which may be similar to that between cydno and
sapho. If the relationship is Mullerian, then it
would have been advantageous for hewitsoni and
pachinus to have rapidly become as similar as
possible, and one would have expected the red
basal spots of hewitsoni to have become reduced
to the smallest dimensions that were commen-
surate with the efficient performance of their
function. Similarly, if pachinus had had red
basal spots or had acquired them later, they
should have increased in size until they matched
those of hewitsoni. But we find that the basal
spots of hewitsoni are much larger than is usual,
as if it is advantageous for it to maintain its iden-
tity. The situation suggests that relationship is
Batesian rather than Mullerian.
The closeness of the match of the color-pat-
tern in cydno and sapho leaves no doubt that the
relationship is mimetic, and H. cydno may lack
basal spots because, unlike pachinus, it has not
yet re-evolved them. If these arguments are cor-
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Text-figs. 119-131. Ventral view of left hindwings of Heliconius species to illustrate variation in the
basal spot complex. 119, H. lybius lybius; 120, H. natteri; 121, H. hierax; 122, H. doris; 123, H.
egerius; 124, H. wallacei; 125, H. burneyi; 126, H. aoede; 127, H. xanthocles; 128, H. pachinus; 129,
H. atthis; 130, H. ethillus or H. aristionus ; 131, H. melpomene. About twice natural size.
rect, palatability trials with suitable predators
should reveal that hewitsoni and sapho are both
more distasteful than pachinus and cydno. If,
however, the red basal spots are important in
courtship as a recognition mechanism, then the
persistence of this character may be necessary in
sapho for reproductive isolation. This could be
investigated experimentally.
While these northwestern species were differ-
entiating in what are now the Colombian Andes,
the main evolution of the genus was taking place
in eastern Ecuador and northeastern Peru. With
1965]
Emsley: Speciation in Heliconius
249
Text-figs. 132-140. Ventral view of left hindwing of Heliconius species to illustrate variation in red basal
spot complex. 132, H. telesiphe ; 133, H. clysonymus, 134, H. hortense; 135, H. himerus; 136, H. herma-
thenae; 137, H. charitonius; 138, H, demeter; 139, H. ricini; 140, H. erato. About twice natural size.
the continued uplift of the Andes towards the
end of the Miocene, the inland sea (Map 29)
was drained, and Heliconius seems to have ex-
ploited the opportunity for recolonization. The
present Amazonian representatives of the genus,
with the exception of hermathenae, exhibit only
two types of color-pattern. These are a more or
less iridescent blue ground color with one or two
yellow forewing bands (wallacei, metharme,
sarae, antiochus, leucadius, sapho congener and
doris doris), and a complex pattern which dis-
plays a black wing tip, a yellow forewing band
of variable width and an orange or red wing base.
This black-yellow-red (B-Y-R) pattern may be
achieved by the expression of dennis and ray
characters (Text-figs. 5-8, 10) as in the species
eanes, tales, aoede, burneyi, egerius, xanthocles,
elevatus, melpomene, erato, demeter and doris
delilae, or by variation in expression of spots and
bars as in isabellae, numatus, aristionus and
ethillus.
The dennis-ray species of wide distribution
acquire other patterns beyond the limits of the
Amazon basin and exhibit acute polychromatism
in the transitional zones of central Colombia, the
Guianas, central Bolivia and at about the 850
meter level in the Ecuadorian Andes, and at com-
parable ecological levels to the north and south.
The species which behave most spectacularly in
this respect are melpomene and erato, for in
both the forewing band changes from yellow to
red, dennis and ray are lost, and a yellow hind-
wing bar and increased iridescence acquired.
This has been described and discussed in detail
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Text-figs. 141-147. Red basal spots in Heliconius. 141, H. leucadius; 142, H. sarae; 143, H. hygianus;
1 44, H. antiochus; 1 45, H. sapho sapho; 1 46, H. hewitsoni; 1 47, H. sapho congener. About twice nat-
ural size.
in Emsley (1964). The Amazonian species
which effect the B-Y-R pattern with spots and
bars change most obviously in the eastern Andes,
where the patterns of numatus, ethillus , aristio-
nus, isabellae and vibilius become more exten-
sively orange and black at the expense of the
yellow. There is no experimental and little ob-
servational evidence to suggest the cause of the
apparently strong selection for a B-Y-R pattern
in the Amazon basin, but the most likely expla-
nation, for which some evidence was offered in
Emsley (1964), is that it is due to a mimetic
situation in which the Danainae act as models.
The systematics and evolution of the Danainae
are pertinent and should be investigated. To what
extent Mullerian relationships within Heliconius
are operative is unknown.
The hypothesis that the species-groups of
Heliconius had differentiated by the early Mio-
cene is supported by the fact that almost all the
groups have at least one member in this Ama-
zonian complex.
A completely unexplained phenomenon is the
uniformity of the variation in the shape of the
yellow forewing band in all the dennis-rayed
species in the Amazon basin. The specimens
from the Lower Amazon have a broad spotted
forewing band centered over the apex of the dis-
cal cell, but specimens from westerly localities
have the band narrow and rectangularly com-
pact and distal to the discal cell. There is also
a cline in the intensity and development of ray
from the Guianas, where it is least, to the south
and west where it is most intense.
There is considerable variation in the dennis,
ray and forewing band characters of melpomene
1965]
Emsley: Speciation in Heliconius
251
Text-figs. 148-160. Variation in the shape of the signa in Heliconius, as viewed from the right. 148,
H. pavanus; 149, H. edias; 150, H. lineatus, or isabellae, or eanes, or vibilius , 151, H. lybius left side;
152, H. lybius right side; 153, H. tales left side; 154, H. tales right side; 155, H. hierax; 156, H. aoede,
or godmani, or metharme; 157, H. wallacei or burneyi; 158, H. xanthocles; 159, H. hecubus ; 160, H.
at this.
in the vicinity of Obidos, Brazil. West of this
area all these butterflies have a yellow forewing
band, dennis and ray, but progressing towards
the northeast more and more specimens have
red on the forewing band and lack dennis and
ray. Around Obidos it had seemed that the red-
banded non-dennis non-ray form was rare, but
a series of reliably labelled specimens in the
American Museum of Natural History, all taken
from one locality very near Obidos on one occa-
sion, exhibit the red-banded non-dennis non-ray
pattern that is characteristic of Trinidadian mel-
pomene. Therefore it would seem that selection
among the various B-Y-R color-patterns differs
not only geographically but perhaps temporally
also. A detailed examination of label data might
indicate whether these fluctuations are seasonal,
annual or irregular.
The only red-banded species other than erato
and melpomene is H. hermathenae, which has
also been taken from the Obidos area. It is rela-
tively rare and may be maintained at a low popu-
lation level by periodic “boosts” which select for
the red-banded non-dennis non-ray color-pattern
in melpomene (and erato?). The charitonius-
type yellow markings of hermathenae are prob-
ably a relatively primitive character, the red of
the forewing band having been acquired inde-
pendently of that of erato and melpomene.
As the sympatric forms of numatus, aristionus
and ethillus vary together throughout their range,
the close similarity in their general appearance
suggests a mimetic relationship. In Honduras,
where ethillus occurs in the absence of numatus
and aristionus, ethillus fornarinus is quite unlike
any other form of any other species in the com-
plex. The ventral pattern is like that of H. cydno,
and the over-all appearance is very similar to
that of H . hecale, which is an uncommon species
restricted to a few localities in the Guianas. Both
cydno and hecale are members of the same spe-
cies group as ethillus. In view of the close syste-
matic relationship between ethillus and hecale, it
is possible that hecale represents a relic of the
stock from which ethillus evolved which has re-
tained the ancestral color-pattern. This is sup-
ported by the hecale-Yike appearance of ethillus
in Honduras, where numatus does not occur.
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16!
162
163
164
165
166
0-5 mm
Text-figs. 161-172. Variation in the shape of the female abdominal processes in Heliconius. 161, H.
alipherus or lineatus or vibilus or earns or isabellae or hierax or natteri; 162, H. wallacei or burneyi or
egerius; 163, H. xanthocles or hecubus or doris; 164, H. melpomene or cydno or pachinus or numatus
or ethillus or aristionus or hecale; 165,//. metharme or godmani or aoede or erato; 166, H. hecalasius or
longarenus; 167, H. hortense or clysonymus; 168, H. hermathenae; 169, H. tales or lybius; 170, H.
edias; 171, H. telesiphe; 172, H. sapho or hewitsom or same or antiochus or leucadius or hygianus or
ricini or demeter or charitonius.
This is further supported by the occurrence of
similar elements of the color-pattern in cydno.
Since the species clysonymus, hortense, hime-
rus, hierax, hygianus and ricini are all allopatric,
there are probably no mimetic relationships
among them. The red bar on the hindwing may
be a persistent primitive character if the ability
to produce red pigment were a prerequisite to
the colonization of the Amazon basin by the
B-Y-R patterned species. The relationship be-
tween clysonymus and hortense is uncertain be-
cause, though they are similar both morphologic-
ally and in color-pattern, the range of the former
in Central America does not extend up to that
of hortense (Map 22). In view of its advanced
morphological features, hortense can hardly be
a North American relic as is possible for lineatus.
Many of the species alleged to have evolved
in the Amazon basin have spread over more
or less the whole range of the genus. It has al-
ready been noted that those species possessing
the B-Y-R facies adopt another pattern outside
the Amazon basin, but the iridescent blue and
yellow species (IB-Y) have retained their char-
acteristic configuration with only minor modi-
fications over their whole range, as in sarae
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Emsley: Speciation in Heliconius
253
Text-fig. 173. Dendrogram illustrating the evolutionary relationships of Heliconius.
wallacei, antiochus and doris doris. This pattern
may be disruptive and without mimetic signifi-
cance. The only form of H. sapho that occurs
beyond the range of the mimetic H. cydno is
congener from the eastern Ecuadorian Andes,
which also has the iridescent blue ground color
and a pair of forewing yellow bands.
Heliconius doris is one of the more remark-
able species, for through dichromatism it effects
both the B-Y-R and IB-Y patterns. The forms
doris and aristomache have normal yellow fore-
wing bands but accomplish the iridescent blue
effect by having a brilliant blue ray pattern on
the hindwing. These two forms are widely dis-
tributed over South and Central America respec-
tively. In the Amazon basin there is a dichrom-
atic form delilae in which the blue rays are
overprinted with a bright red and there is red
dennis on the forewing. This produces a good
B-Y-R appearance. However, in Central
America there is another form, eratonius, in
which the blue rays are overprinted by red rays
of a different type from those of delilae. Though
it seems that the red rays have evolved inde-
pendently in the doris of Central America, the
stimulus is not known. In southern Central and
northern South America, H. doris is trichrom-
atic, for in addition to the forms with blue or
red rays there are forms with green rays which
are composed of variable combinations of yel-
low, green and blue scales. The significance is
not known but the pattern of the rays is similar
to those of the blue forms. While it is possible
that the wing colors in Heliconius may be in-
fluenced by the larval food plant, in H. doris
this is not the case, for in Trinidad all three
forms have been reared from one brood of eggs
laid by a single female and fed on one species
of Passiflora.
In review, it seems that the existing species of
Heliconius still portray the phases through which
the color-patterns have passed. The figures in
parentheses refer to the color plates of Seitz
(1913). There are also some excellent color
plates in Eltringham (1916).
It is suggested that the earliest Heliconius were
orange with longitudinal black markings as in
alipherus (80a), lybius (80a), linealus (79f)
and Colaenis iulia (84b). The evolution of yel-
low pigment would have led to the design of
natteri (78f), which with the exposure of spots
and bars of ground color in the light areas yields
patterns like those of isabellae (80d-g), vibilius
(79e, f), longarenus and charitonius (79a).
Accentuation of the spottedness of the forewing
and the richness of the orange of the hindwing
254
Zoologica: New York Zoological Society
[50: 14: 1965]
gives the pattern seen in edias (79d, e), hecala-
sius (76e), godmani and the diversity seen in
numatus, aristionus and ethillus (72-74). Con-
centration of the forewing yellow into discrete
bands, together with reddening of the hindwing,
produces the pattern of himerus (78a), hierax
(77d), hygianus (79a), clysonymus (79b), hor-
tense (79c) and ricini (79d).
The iridescent blue ground color with discrete
yellow forewing bands (the IB-Y pattern of
wallacei (77d-e), sarae {lit, 78a), leucadius
(lit), antiochus (lit) , sapho (lie)) is consid-
ered the penultimate pattern, the most recently
evolved being the independently acquired
dennis-ray (B-Y-R) characters of melpomene
(75, 76a-d), erato (78a-f), aoede (76f) xantho-
cles (77b), burneyi (77a), egerius, elevatus, de-
meter (78e) eanes (80c) and tales (80b).
VI. Summary
From a study of the meso- and meta-pretarsal
paronychia, female abdominal processes, sperm-
atheca, signa and protarsi, male genital valves
and androconial distribution, alary color-pattern
and geographic distribution, the genus Helicon-
ius is shown to be composed of forty-six species
in thirteen species groups in the two subgenera
Eueides and Heliconius. The geographic varia-
tion and polychromatism within these species is
described and discussed and a hypothetical evo-
lutionary history is postulated for the genus in
conjunction with the palaeogeography of Central
and South America.
VII. General References
Eltringham, H.
1916. On specific and mimetic relationships in
the genus Heliconius. Trans. R. ent. Soc.
Lond., 101-148, 1 17 figs., 2 col. plates.
Emsley, M. G.
1963. A morphological study of imagine Heli-
coniiae (Lep. Nymphalidae) with a con-
sideration of the evolutionary relationships
within the group. Zoologica, N. Y., 48:
85-130, 153 figs., 17 maps, 1 pi.
1964. The geographical distribution of the color-
pattern components of Heliconius erato
and Heliconius melpomene with genetical
evidence for the systematic relationships
between the two species. Zoologica, N. Y.,
49: 245-286, 15 tabs., 15 figs., 1 map, 2
col. pis.
Lloyd, J. J.
1963. Tectonic history of the south Central-
American orogen. In Backbone of the
Americas, a symposium, ed. Childs, O. E.
and Beebe, B. W., Memoir 2, Wisconsin.
Michener, C. D.
1942. A generic revision of the Heliconiinae
(Lepidoptera, Nymphalidae). Am. Mus.
Novit., No. 1197: 1-8, 17 figs.
Neustetter, H.
1929. Heliconiinae. In Lepidopterorum Cata-
logus (Edit. Strand), pt. 36: 1-136, Berlin.
Seitz, A.
1916. Macrolepidoptera of the world, 5. The
American Rhopalocera. Heliconiinae: 375-
399, 593-597, pis. 72-80, (With appendix).
Sheppard, P. M.
1963. Some genetic studies of Mullerian mimics
in butterflies of the genus Heliconius.
Zoologica, N. Y., 48: 145-154, 2 pis.
Stichel, H., & H. Riffarth
1905. Heliconiidae. Das Tierreich, 22: 1-290,
50 figs., Berlin.
Turner, J. R. G., C. A. Clark & P. M. Sheppard
1961. Genetics of a difference in the male geni-
talia of East and West African stocks of
Papilio dardanus (Lep.). Nature, Lond.,
191: 935-936.
Turner, J. R. G., & J. Crane
1962. The genetics of some polymorphic forms
of the butterflies Heliconius melpomene
Linnaeus and H. erato Linnaeus. I, Major
genes. Zoologica, N. Y., 47: 141-152, 1 fig.,
1 pi.
Weeks, L. G.
1947. Paleogeography of South America. Bull.
Am. Ass. Petr. Geol., 31, No. 7: 1194-
1241, 17 figs.
15
A Technique for the Recording of Bioelectric
Potentials from Free-flying Insects ( Lepidoptera : Heliconius erato )1,2
S. L Swihart & J. G. Baust
Department of Biology,
State University of New York,
Fredonia, New York
(Plates I & II)
[This paper is a contribution from the William
Beebe Tropical Research Station of the New York
Zoological Society, at Simla, Arima Valley, Trini-
dad, West Indies. The station was founded in 1950
by the Zoological Society’s Department of Tropical
Research, under Dr. Beebe’s direction. It comprises
250 acres in the middle of the Northern Range,
which includes large stretches of government forest
reserves. The altitude of the research area is 500 to
1,800 feet, and the annual rainfall is more than
100 inches.
[For further ecological details of meteorology
and biotic zones, see “Introduction to the Ecology
of the Arima Valley, Trinidad, B. W. I.,” by William
Beebe, Zoologica, 1952, 37 (13) 157-184.
[The success of the present study is in large mea-
sure due to the cooperation of the staff at Simla,
especially of Jocelyn Crane, Director, and Dr. M. G.
Emsley, Assistant Director, who contributed so
freely of their knowledge of the organisms studied.
The authors particularly wish to acknowledge the
invaluable assistance rendered by Dr. Donald R.
Griffin of the Rockefeller University and the New
York Zoological Society],
Introduction
In spite of extensive and highly imaginative
study of the neurological control of insect
behavior, many fundamental questions re-
main unanswered. Even the role of the brain
remains a subject of controversy. Roeder (1963)
stressed the role of inhibition, while other work-
ers ( e.g ., Wiersma, 1962) have contended that
this effect has been overemphasized.
Supported by grants from the National Science
Foundation (NSF-GB-2331 and NSF-GB-4218).
Contribution No. 1071, Department of Tropical Re-
search, New York Zoological Society.
Even as basic a question as the nature of the
control mechanisms responsible for the initia-
tion and maintenance of flight remain unan-
swered. Weis-Fogh ( 1956) gave evidence for the
purely reflex control of the non-fibrillar, indirect
flight muscles of the locust, Schistocera, and has
been supported by Pringle (1957). More re-
cently, however, Wilson (1961) gave excellent
evidence of the central nervous system playing
an essential role in supplementing the reflex
mechanisms in the same organism.
Both workers agreed that decerebrate animals
possessed all the mechanisms necessary for nor-
mal flight. That the brain should play no role in
such activities is somewhat surprising when one
considers that similar basic motor patterns, e.g.,
walking (Roeder, 1963) and sound production
(Huber, 1960), have been shown to be related
to protocerebral activity. It seems likely that, at
a minimum, such centers must be involved in
processing the complex sensory input which
arises during flight.
In the past, experiments in this general area
have concentrated on “tethered” flight, whereby
the organism was firmly mounted, usually by the
pterothorax, etc., and then induced to “fly” by
eliciting the tarsal reflex (Fraenkel, 1932), some-
times supplemented by an airsteam. Such a situ-
ation, while having the advantage of control-
ability, obviously fails to truly simulate actual
flight conditions, as the variations induced by
pitch, roll, moving field, etc., have been largely
eliminated, thereby minimizing the activity in
any feed-back loops that might exist.
Based upon this background, preliminary in-
vestigations were undertaken to determine the
255
256
Zoologica: New York Zoological Society
[50: 15
practicability of recording bioelectric potentials
from insects permitted to fly with comparative
freedom. This note reports the development of
a simple technique which has allowed the record-
ing of an “electro-encephalogram” from free-
flying butterflies, while simultaneously recording
photographically the physical activity of the or-
ganism.
Methods and Materials
Heliconius erato adonis , used in these experi-
ments, is a medium-sized (21/2" wingspread),
black, neotropical butterfly with brilliant scarlet
wing patches. It has been the subject of numer-
ous studies including: genetical (Emsley, 1964),
behavioral (Crane, 1955), and electrophysio-
logical (Swihart, 1965).
The insects were normally caught in the wild
and maintained in large outdoor insectaries until
required for experimentation.
The experiments themselves were conducted
in a smaller (6' X 6' X 6') insectary which was
completely enclosed by aluminum screening. The
cage and the electrical equipment were grounded
to earth.
The key element in the technique was the ex-
tremely fine wire which served as both electrode
and lead to amplifier input. Nichrome V alloy
wire with enamel insulation, .001" in diameter,
manufactured by Driver-Harris Co., was em-
ployed. This was found to have a remarkably
high degree of tensile strength and flexibility,
with a resistance of only 5,000 ohms/foot.
With the butterfly restrained, the stripped and
sharpened end of one wire about 4' in length was
placed just beneath the cuticle on the mid-dorsal
surface of the head. A similar wire that served
as an indifferent electrode was inserted into the
dorsal aspect of the thorax or abdomen. Rigid
attachment of the electrodes to the cuticle was
achieved with a rosin-beeswax cement (Fig. 1).
Tangling of the wires was minimized by cement-
ing them together at short intervals with very
small drops of UHU cement. The free ends of the
wires were fitted with pin jacks. Several butter-
flies treated in this manner were observed for
three to four days after the operation, and
showed no apparent ill effects.
The free ends of the wire were connected to
the cathode follower input of a Grass P-6 D.C.
preamplifier which was operated in the single-
ended mode, with the indifferent electrode
grounded directly to earth. The input itself was
suspended from the center of the roof of the
insectary, and consequently the butterfly could
fly freely throughout the upper two-thirds of the
cage.
The amplified potentials were monitored on
a Tektronix 564 oscilloscope and simultaneously
fed into the optical sound track of an Auricon
Cine-Voice 16 mm. camera (Model CM-72A)
equipped with a synchronous motor drive, oper-
ating at 24 frames per second.
Results
The recording obtained by this technique did,
of course, vary with the position of the band-pass
filters of the amplifier. Thus either a high-fre-
quency or low-frequency EEG could be re-
corded. Any form of mechanical stimulation,
such as touching the antennae, abdomen, blow-
ing on the insect, etc., resulted in high frequency,
non-synchronous activity, showing considerable
after-discharge. Little or no major low-frequency
activity accompanied such stimulation (Fig. 2).
On the other hand, as soon as flight was initi-
ated, a well-defined, low-frequency, rhythmic
discharge was observed. This consisted of a brief
train of spikes (1 to 6), followed by a period of
quiet. This pattern repeated itself approximately
17 times per second (Figs. 3, 4). On an average,
the quiet period lasted twice as long as the period
of activity. Frequently the first several trains,
associated with the initiation of flight, contained
a higher average number of spikes than were
recorded during sustained flight. Thus a typical
pattern was 4, 5, 5, 2, 4, 4, 5, 4, 3, 3, 3, 3, 2, 3, 2,
etc.
On a number of occasions recordings were
obtained from insects that were walking and fre-
quently such activity was accompanied by very
slow movements of the wings. Even though the
wing movements were of an amplitude quite sim-
ilar to those made during flight, no low-fre-
quency EEG was detected.
Conclusions
It seems clear that the recorded potentials
originated in the supra-esophageal ganglion. Not
only was the indifferent electrode carefully
grounded to earth, but no detectable difference
in the waveform resulted from changes in its
location ( thorax vs. abdomen) . Furthermore, re-
cordings from the thoracic muscles of Lepidop-
tera show a simple one spike per wingbeat relat-
ionship (Roeder, 1951), while recordings from
the thoracic ganglia (Pringle, 1957) show about
four spikes per wingbeat at regular time inter-
vals. Neither of these patterns is similar to that
recorded from the head.
There is, however, a published report of trains
of spikes associated with flight mechanisms that
is amazingly similar to that observed in the pres-
ent experiments. Wilson (1961) illustrates the
response recorded from nerve IB of Schistocera,
which carries the output of the wing sense or-
1965]
Swihart & Banst: Recording of Bioelectric Potentials in Heliconius
257
gans. His published records show trains of 2 to 5
spikes occurring at the wingbeat frequency, and
separated by periods of quiet twice the duration
of the active period. He further notes, “Activity
in the sensory unit is greatest at the beginning
and end of flight.”
In any case, it seems highly unlikely that such
a variable pattern of discharges can be associated
with the motor neurons of non-fibrillar flight
muscles. On the other hand, the failure to detect
trains when the organism moves the wings very
slowly is consistent with phasic sense organs.
As noted above, Weis-Fogh ( 1956) attempted
to demonstrate the reflex control of flight. Wilson
(1961) pointed out that such mechanisms act
“on top” of what is determined by the central
nervous system. In Wilson’s view, however,
such determination arose in the thoracic ganglia,
since decerebrate animals flew normally.
There is nevertheless some question as to the
level at which such determination occurs. Wilson
reports that severing the connectives between
thoracic ganglia 1 and 2 produced only ambigu-
ous results, while Chadwick (1953) reported
that flight movements never occur if the same
surgery is performed on Periplaneta.
The authors’ personal experience with H.
erato has indicated that even the insertion of a
semi-microelectrode into the protocerebrum of
an otherwise intact animal can result in a serious
impairment of flight ability. When such an or-
ganism is thrown into the air, the wings will be
moved, but the flight is often only an uncoordi-
nated downward spiral. Such animals may be
stimulated to walk and may live for many days
but cannot be induced to demonstrate effective
flight.
Furthermore, our knowledge of the basic
economy of the insect nervous system suggests
that we would not detect the activity of the wing
sense organs in the vicinity of the protocerebrum,
unless that organ was involved in processing this
information.
It is well known that in Schistocera, wind-
sensitive hairs on the head provide an important
input relative to flight activity. These are known
to discharge directly into the cord. In butterflies
there appears to be similar types of organs, i.e.,
the so called Jordan’s organ (Eltringham, 1933).
These are regions between the compound eyes
which contain many fine hairs, easily displaced
by the slightest wind current. The authors have
observed that a butterfly flying in tethered flight
can be stopped virtually instantly by touching
these hairs with a fine camel’s hair brush. As
opposed to the locust hairs, however, the nerve
from this organ is reported to run directly to the
protocerebrum.
On the basis of the foregoing discussion, the
following conclusions are suggested:
( 1 ) It seems possible that there may exist a
whole hierarchy of controls for certain motor
patterns, with each succeeding level capable of
“refining” the activity of the more peripheral
elements. Such a system may extend all the way
“up” to the protocerebrum.
(2) The investigation of such a hypothesis
can, perhaps, be associated by the utilization of
the technique presented in this note, as it would
seem to do much in facilitating the analysis of
neurological activity under conditions tending to
preserve the delicate patterns of sensory input.
References
Chadwick, L. E.
1953. The motion of the wings. Aerodynamics
and flight metabolism. The flight muscles
and their control. In Roeder, K. D„ Insect
Physiology, Wiley, New York.
Crane, J.
1955. Imaginal behavior of a Trinidad butterfly,
Heliconius erato hydara Hewitson, with
special reference to the social use of color.
Zoologica, 40: 167-96.
Eltringham, H.
1933. The Senses of Insects. Methuen, London.
Emsley, M. G.
1964. The geographical distribution of the color-
pattern components of Heliconius erato
and Heliconius melpomene with genetical
evidence for the systematic relationship
between the two species. Zoologica, 49:
245-86.
Fraenkel, G.
1932. Untersuchungen uber die {Coordination
von Reflexen und automatisch-nervosen
Rhythmen bei Insekten. I. Die Flugreflexe
der Insekten und ihre Koordination. Z.
vergleich Physiol., 16: 371-93.
Huber, F.
1960. Untersuchungen unber die Funktion des
Zentralnervensystems und insbesondere
des Gehirnes bei der Forthewegung und
der Lauterzeugung der Grillen. Z. verg-
leich Physiol., 44: 60-132.
Pringle, J. W. S.
1957. Insect Flight. Cambridge University Press,
Cambridge.
Roeder, K. D.
1951. Movements of the thorax and potential
changes in the thoracic muscles of insects
during flight. Biol. Bull., 100: 95-106.
258
Zoologica: New York Zoological Society
[50: 15: 1965]
1963. Nerve Cells and Insect Behavior. Harvard
Univ. Press, Cambridge.
SWIHART, S. L
1965. Evoked potentials in the visual pathway
of Heliconius erato (Lepidoptera). Zoo-
logica, 50: 55-61.
Weis-Fogh, T.
1956. Biology and physics of locust flight. IV.
Notes on sensory mechanisms in locust
flight. Phil. Trans. Roy. Soc. Lond., B,
239: 553-84.
WlERSMA, C. A.
1962. The organization of the arthropod central
nervous system. Amer. Zool., 2: 67-78.
Wilson, D. M.
1961. The central nervous control of flight in a
locust. J. Exp. Biol., 38: 471-90.
EXPLANATION OF THE PLATES
Plate I
Fig. 1. H. erato with the recording electrode ce-
mented firmly beneath the cuticle of the
mid-dorsal portion of the head. The wire
was placed beneath the cuticle and then
looped through the rosin-beeswax cement
so that attachment would be stronger. The
picture also shows the indifferent electrode
held beneath the cuticle of the dorsal por-
tion of the thorax (far right) and then
held by a second drop of cement to insure
rigid attachment.
Fig. 2. H. erato being stimulated mechanically by
touching the abdomen with a pin (a, i,
h, g) while feeding on Lantana flower. The
result of such stimulation was high-fre-
quency, non-synchronous activity showing
considerable after-discharge. In this figure,
as in Fig. 3, the optical tract of the film
has been shifted in position to compensate
for the normal displacement of the cam-
era’s recording head from the photo-
graphic image.
Plate II
Fig. 3. In this sequence, while walking towards a
flower taped to the side of the cage, H.
erato has been stimulated to fly by a flash
of light (a). Prior to actual flight (a through
f), the optical tract shows only the typical,
high-frequency, non-synchronous dis-
charge. However, as free flight commences
(g through j), the pattern is changed to a
well-defined pattern of low-frequency,
rhythmic discharge. This pattern is re-
peated twice; between frames h and i, and
toward the end of frame j.
Fig. 4. A longer portion of the optical track dur-
ing a period of free flight. The low-fre-
quency, rhythmic discharge can be ob-
served as consisting of brief trains of
spikes. Each activity train is then followed
by a period of quiet approximately twice
the length of the active period. Spikes may
number between 1 and 6 per train, and
the pattern repeats itself approximately 17
times per second. This particular sequence
lasted V3 sec. and shows 5 Vi trains of
3-4 spikes.
SWIHART 8c BAUST
PLATE I
Fig. 1
Fig. 2
j i h g f
A TECHNIQUE FOR THE RECORDING OF BIOELECTRIC POTENTIALS FROM FREE-FLYING INSECTS
( LEP1DOPTERA: HELICONIUS ERATO)
SWIHART & BAUST
PLATE II
mF’iTwniii wpiii P'fM iv^pv ^wfr t )*pM*pyyy j
Fig. 4
A TECHNIQUE FOR THE RECORDING OF BIOELECTRIC POTENTIALS FROM FREE-FLYING INSECTS
(LEPIDOPTERA: HELICONIUS ERATO)
[1965]
Zoologica: Index to Volume 50
259
Names in bold face indicate new
genera, species or sqbspecies; num-
bers in bold face indicate illustra-
tions; numbers in parentheses are
the series numbers of papers con-
taining the plates listed immediately
following.
A
Acerina cernua, (9) PI. II, 85
Aequidens portalegrensis, (9)
PI. Ill, IX, 85, 87
pulcher, 85, 87
Aleutera schoepfii, 86
Amia calva, 64
Amphiprion percula, 85
Angelichlhys ciliaris, 85
isabelita, 85
Anolis barkeri, 41, (2) PI. I
B
Brevoortia brevicaudala, 64
C
Calamoichthys calabaricus, 64
Carcharias limbatus, 64
Carcharinus sp., 79
Cathaemasia senegalensis, 67, 68
Ceratacanlhus schoepfii, 86
Chaetodon ocellalus, 64
striatus, 85
Cichlosoma synspilum, 85
D
Danaus gilippus berenice (1)
PI. I, II, IV, VI, VII, 14-18
gilippus xanthippus, (1)
Pis. I, II, III, VII
Dasyatis americana, 64
Delphinaplerus leucas, 65
Dormitator maculalus, (9) Pi. I, 86
E
Electrophorus electricus, 64
Ephippiorhynchus senegalensis, 67
F
Forcipiger longiroslris, (9)
PI. IV, 85, 87
Fundulus heteroclitus, 64, 85
G
Glyptocephalus zachirus, 116
Gymnarchus niloticus, 64
INDEX
H
Heliconius alipherus, 195,
196, 197, 236, 242, 252
antiochus, 219, 241, 247, 250, 252
aoede, 202, 239, 242, 248, 251, 252
aristionus, 197, 208, 238, 243,
248, 252
atthis, 208, 238, 243, 248, 251
burneyi, 203, 237, 242, 248,
251, 252
charitonius, 217, 241, 246,
249, 252
clysonymus, 216, 241, 246,
249, 252
cydno, 197, 212, 238, 243, 252
demeter, 217, 241, 247, 249, 252
doris, 197, 204, 239, 243,
248, 252
eratonius, 194
eanes, 199, 236, 242, 251, 252
edias, 196, 236, 242, 244,
251, 252
egerius, 204, 242, 248, 252
aslreus, 237
egerius, 237
elevalus, 210, 238, 243
erato, 55, (5) Pis. I-III,
196, 197, 215, 240, 247, 249, 252
adonis, 256, (15) Pis. I & II
ethillus, 197, 209, 238, 243,
244, 248, 252
(Euides) alipherus, 196
isabellae, 196
vibilius lampeto, 197
godmani, 202, 239, 242, 251, 252
hecalasius, 214, 240, 246, 252
hecale, 197, 210, 252
hecubus, 205, 239, 243, 244,
251, 252
(Heliconius) melpomene, 196
pachinus, 197
sapho congener, 197
hermathenae, 214, 240, 246,
249, 252
hewitsoni, 220, 241, 247,
250, 252
hierax, 202, 237, 242, 248,
251, 252
himerus, 215, 240, 246, 249
hortense, 216, 241, 246, 249, 252
hygianus, 218, 241, 247, 250, 252
isabellae, 196, 199, 236, 242,
251, 252
leucadius, 218, 241, 247, 250, 252
lineatus, 199, 236, 242, 251, 252
longarenus, 214, 240, 246, 252
lybius, 200, 236, 242, 251, 252
lybius, 248
melpomene, 196, 197, 211,
238, 243, 248, 252
limaretus, 194
metharme, 203, 239, 242, 251, 252
nalteri, 201, 238, 242, 248, 252
numatus, 197, 207, 238, 243,
244, 252
pachinus, 197, 213, 248, 252
pavanus, 198, 236, 251
ricini, 217, 241, 247, 249, 252
sapho, 219, 241, 247, 252
congener, 250
sapho, 250
sarae, 217, 241, 250, 252
tales, 201, 236, 242, 251, 252
telesiphe, 215, 241, 246, 249, 252
vibilius, 198, 236, 242, 251, 252
wallacei, 196, 203, 237, 242,
248, 251, 252
xanthocles, 206, 239, 243, 248,
251, 252
Hemichromis bimaculatus, 87
Hippocampus hudsonius, 64
Hippoglossoides elassodon, 116
hippoglossus, 116
plalessoides, 86
Hydrolagus colleii, 64
Hypsoblennius gentilis, 86
jenkinsi, 86
L
Lachnolaimus maximus, 86
Laclophrys cornulus, 86
tricornis (9) PI. I, 86
Lepidopsetta bilineala, (11)
Pis. I, V, VII, IX, XI, 116
Lepomis cyanellus X
L. macrochirus, 85
gibbosus, 85
humilis, 85
machrochirus, 85, 87
megalolis, 85
pallidus, 85
Leptonycholes weddelli, 45, (3)
PI. I
Limanda Timanda, 86
Lobotes surinamensis, 64
Lycora ceres ceres, (1) PI. V
M
Macropodus opercularis, 85
viridiauratus, 86
Malapterurus electricus, 64
Micropterus (Huro) salmoides, 85
pseudaplites, 85
Microslomus pacificus, 116
Morone americana, (9) PI. IV, 85
Mugil cephalus, (10) Pis. Ill, IV
Mullus surmuletus, 85
Mustelus canis, 64
Myxine glutinosa, 64
260
Zoologica: Index to Volume 50
[1965]
N
Negaprion brevirosiris, 64
O
Ophiodon elongatus, 86
Opislhognalhus aurifrons, 64
Opsanus tau, 64
Osmerus eperlanus, 85
Osleoglossum bicirrhosum, 64
P
Parophrys velulus, (11) PI. II, 116
Perea flavescens, 85
Phoca hispida, 65
groenlandicus, 65
vilulina, 65
Pleuronectes ilesus, 86
limanda, 86
(Limanda) limanda, 116
plalessa, 86, 116
Polypterus ornalipinnis, 64
Pomacanlhus arcuatus, 85
Pomaiomus sallalrix, 64
Pomoxis annularis, 85
nigromaculatus, 85
Premnas biaculealus, 85
Prionotus evolans, 64
Pseudemys floridana, 65
Pseudopleuronectes americanus, 116
Psiltichlhys melanoslicus, 116,
(11) Pis. I-XI
R
Rana clamilans, 47
pipiens, 65
Roccus linealus, (9) PI. IV, 85
S
Sargus annularis, 85
Scatophagus argus, (9) PI. I, 85
Serranus alrieauda, 85
Solea solea, 116
vulgaris, 86
Spheroides maculalus, 64
Sphyrna liburo, 64
zygaena, 79
Slizosiedion canadensis griseus, 85
glaucum, 85
vitreum, (9) PI. II, 85
Symphysodon discus, (9) PI. I, 86
T
Thunnus Ihynnus, 79, (8) PI. II,
(10) PI. II
Tilapia macrocephala, 87
ovale, 87
sparmanii, 87
Triturus viridescens, 65
U
Uca minax, 123
pugilator, 123, 125, 129, 133, (12)
Pis. I-V
pugnax,123
Urolophus jamaicensis, 64
X
Xiphophorus maculalus, 151, 153
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ZOOLOGICA
SCIENTIFIC CONTRIBUTIONS OF THE
NEW YORK ZOOLOGICAL SOCIETY
VOLUME 51 • 1966 • NUMBERS 1-12
PUBLISHED BY THE SOCIETY
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Contents
Issue 1. May 18, 1966
PAGE
1. Eastern Pacific Expeditions of the New York Zoological Society. XLVI.
Oxystomatous and Allied Crabs from the West Coast of Tropical America.
By John S. Garth. Text-figures 1 & 2 1
2. Behavior of Infant Rhesus Monkeys and Their Mothers in a Free-ranging
Band. By John H. Kaufmann. Plates I-IV. 17
3. Head Muscles of Boa constrictor. By Frances W. Gibson. Text-figures
1 & 2 29
4. The Behavior of Solenodon paradoxus in captivity with Comments on the
Behavior of Other Insectivora. By John F. Eisenberg & Edwin Gould.
Plates I & II 49
Issue 2. September 15, 1966
5. The Capture and Care of a Killer Whale, Orcinus orca, in British Columbia.
By Murray A. Newman & Patrick L. McGeer. Plates I-VIII; Text-
figures 1 & 2 59
6. Sound Structure and Directionality in Orcinus (killer whale). By William
E. Schevill & William A. Watkins. Figures 1-5 71
7. Effects of Vitamin Antimetabolites on Lebistes reticulatus. By George S.
Pappas. Text-figures 1 & 2
77
Issue 3. November 29, 1966
PAGE
8. A Digenetic Trematode, Parahaplometroid.es basiliscae Thatcher, 1963,
from the Mouth of the Crested Lizard, Basiliscus basiliscus. By Horace W.
Stunkard & Charles P. Gandal. Plates I & II 91
9. Enzootics in the New York Aquarium Caused by Cryptocaryon irritans
Brown, 1951 ( = Ichthyophthirius marinas Sikama, 1961 ), a Histophagous
Ciliate in the Skin, Eyes and Gills of Marine Fishes. By Ross F. Nigrelli &
George D. Ruggieri, S.J. Plates I-VII 97
10. Analysis of Underwater Odobenus Calls with Remarks on the Develop-
ment and Function of the Pharyngeal Pouches. By William E. Schevill,
William A. Watkins & Carleton Ray. Plates I-V; Phonograph Disk. . . 103
Issue 4. February 20, 1967
1 1 . Gene and Chromosome Homology in Fishes of the Genus Xiphophorus.
By Klaus D. Kallman & James W. Atz. Plates I- VI; Text-figure 1 107
12. On the Marking Behavior of the Kinkajou ( Potos flavus Schreber). By
Ivo Poglayen-Neuwall. Plates. I-III 137
Index to Volume 51
143
&f O, £73
ZOOLOGICA
SCIENTIFIC CONTRIBUTIONS OF THE
NEW YORK ZOOLOGICAL SOCIETY
VOLUME 51 • ISSUE 1 * SPRING, 1 966
PUBLISHED BY THE SOCIETY
The ZOOLOGICAL PARK, New York
Contents
PAGE
1. Eastern Pacific Expeditions of the New York Zoological Society. XL VI.
Oxystomatous and Allied Crabs from the West Coast of Tropical America.
By John S. Garth. Text-figures 1 & 2 1
2. Behavior of Infant Rhesus Monkeys and Their Mothers in a Free-ranging
Band. By John H. Kaufmann. Plates I-IV 17
3. Head Muscles of Boa constrictor. By Frances W. Gibson. Text-figures
1 & 2 29
4. The Behavior of Solenodon paradoxus in captivity with Comments on the
Behavior of Other Insectivora. By John F. Eisenberg & Edwin Gould.
Plates I & II 49
Zoologica is published quarterly by the New York Zoological Society at the New York
Zoological Park, Bronx Park, Bronx, N. Y. 10460, and manuscripts, subscriptions, orders for back
issues and changes of address should be sent to that address. Subscription rates: $6.00 per year;
single numbers, $1.50, unless otherwise stated in the Society’s catalog of publications. Second-class
postage paid at Bronx, N. Y.
Published May 18, 1966
1
Eastern Pacific Expeditions of the New York Zoological Society.
XLVI. Oxystomatous and Allied Crabs from the West
Coast of Tropical America.1,2
John S. Garth
Allan Hancock Foundation
University of Southern California
(Text-figures 1 & 2)
[This is the forty-sixth of a series of papers deal-
ing with the collections of the Eastern Pacific Ex-
peditions of the New York Zoological Society made
under the direction of William Beebe. The present
paper is concerned with specimens taken on the
Templeton Crocker Expedition (1936) and the
Eastern Pacific “Zaca” Expedition (1937-1938).
For data on localities, dates', dredges, etc. refer to
Zoologica, Vol. XXII, No. 2, pp. 33-46, and Vol.
XXIII, No. 14, pp. 287-298.]
CONTENTS
Page
Introduction 1
Ecological Considerations 2
Geographical Considerations 2
Systematic Considerations 3
Restriction of Synonymies 4
Explanation of Measurements 4
Acknowledgment 4
Systematic Discussion 4
Section Brachyura 4
Subsection Dromiacea 4
Superfamily Dromiidea 4
Family Dromiidae 4
Dromidia larraburei Rathbun 4
Hypoconcha panamensis Smith 4
Family Dynomenidae 5
Dynomene Ursula Stimpson 5
Subsection Oxystomata 5
Family Dorippidae 5
Ethusa mascarone panamensis Finnegan 5
Contribution No. 1085, Department of Tropical Re-
search, New York Zoological Society.
Contribution No. 282, Allan Hancock Foundation,
University of Southern California.
Ethusa lata Rathbun 6
Ethusa ciliatijrons Faxon 6
Clythrocerus edentatus, new species ... 6
Family Leucosiidae 8
Ebalia magdalenensis Rathbun 8
Lithadia cumingii Bell 8
Uhlias ellipticus Stimpson 8
Peresphona edwardsii Bell 9
Persephona townsendi (Rathbun) 9
Leucosilia jitrinei (Saussure) 9
Randallia ornata (Randall) 10
Randallia bulligera Rathbun 10
Randallia agaricias Rathbun 10
Randallia minuta Rathbun 11
Iliacantha hancOcki Rathbun 11
Ilicantha schmitti Rathbun 11
Family Calappidae 12
Calappa convexa Saussure 12
Calappa saussurei Rathbun 12
Mursia gaudichaudii (Milne Edwards) . . 13
Cycloes bairdii Stimpson 13
Hepatus kossmanni Neumann 14
Hepatella arnica Smith 14
Osachila lata Faxon 14
Osachila levis Rathbun 15
Osachila sona Garth 15
Literature Cited 15
Introduction
THE oxystomatous crabs of the families
Dorippidae, Leucosiidae, and Calappidae,
together with the allied crabs of the fam-
ilies Dromiidae and Dynomenidae, constitute
the subject matter of this report, the third in a
series dealing with the crabs of the Eastern Pa-
cific Expeditions of the New York Zoological
1
2
Zoologica: New York Zoological Society
[51: 1
Society. Unlike the previous two, which were
based on non-intertidal brachygnaths (Garth,
1959, 1961b), the intertidal brachygnaths hav-
ing been previously reported upon (Crane, 1947),
the present report covers both subtidal and inter-
tidal forms. It has therefore been given a differ-
ent title and is not designated as part 3. The gen-
eral statements made in the introductory sections
of part 1 and part 2 nevertheless apply, and will
be supplemented only as required by the group
under consideration.
The oxystomatous and allied crabs of America
were the subject of monographic treatment as
recently as 1937, while the “Zaca” Expedition
was in progress. Prior to this time the waters of
the eastern Pacific had been plied by the “Velero
III”, the oxystomatous crabs receiving the per-
sonal attention of Dr. Waldo L. Schmitt, mem-
ber of the Hancock Expeditions of 1933-34-35,
who saw that they came to the notice of the late
Dr. Mary J. Rathbun, who described them in two
preliminary papers (Rathbun, 1933, 1935).
Those that escaped immediate description were
either described in the monograph referred to
(Rathbun, 1937) or subsequently by the writer
(Garth, 1940). Therefore, although the “Zaca”
did as well in collecting this group as any other,
the 28 species obtained were already described
or in process of description, the single exception
being the Clythrocerus species described herein.
Attention was therefore directed towards the
brachygnathous groups, which had not been
monographed as recently, with the result that
the oxystomatous crabs and their allies, although
first in the systematic arrangement, are the last
to be reported upon.
Ecological Considerations
The field notes of Miss Jocelyn Crane have
been quoted extensively. These, while not as de-
tailed as for some of the groups more readily ac-
cessible to direct observation, nevertheless serve
to provide a useful frame of reference. Color in
life is recorded for 14 of the 28 species, while
aquarium behavior is recorded for Randallia
ornata and Cycloes bairdii. The use of Calappa
convexa as food and its method of capture by
native divers are reported. The placement of sea
anemones carried as commensals by Hepatus
kossmanni is noted, as is the infestation of this
species by a rhizocephalan parasite. The pelecy-
pod shells used as cover by Hypoconcha pana-
mensis have been identified as Glycymeris multi-
costata (Sowerby) and Papyridea aspera
(Sowerby). While the great majority of species
was obtained by shallow dredging, Uhlias ellip-
ticus, heretofore regarded as an intertidal form,
was found in coral obtained by diving. Also,
since no station number or depth is given, it is
assumed that specimens of Leucosilia jurinei
were collected ashore. Breeding season is in-
ferred from the presence of ovigerous females.
These were encountered for eight species in the
November-January period, with a concentration
in mid-December, and for three species in
March.
Geographical Considerations
The ranges of most of the species treated are
coextensive with the limits of the Panamic faunal
province, or from Magdalena Bay (exceptionally,
Cedros Island), Lower California, Mexico, to
Santa Elena Bay, Ecuador (exceptionally, Se-
chura Bay, Peru). To these ranges the records
of the “Zaca” can add little, since her activities
fell well within these limits ( See text-fig. 1 ) . How-
ever, where species are known from such widely
separated localities as the Bay of Panama and
the Gulf of California, often with but a single
record from each, the “Zaca” collections help
to obliterate the apparent discontinuities by fill-
ing in the intermediate localities, usually from
the southern end. Thus the range of Ethusa cil-
iatifrons, known previously from the Bay of
Panama, is extended northward to the Gulf of
Nicoya, Costa Rica, in the direction of its re-
cently reported occurrence in the Gulf of Cali-
fornia (Garth, 1961a), while the range of Ilia-
cantha schmitti, known previously from Ecuador
and Colombia (Rathbun, 1937), is similarly ex-
tended northward to Judas Point, Costa Rica.
Again bridging gaps in existing ranges, a “Zaca”
record for Uhlias ellipticus provides the first con-
tinuity between the type locality, Panama, and
San Jose Island, Gulf of California (Rathbun,
1937), while a series of stations in Nicaragua,
El Salvador, and Guatemala provides stepping-
stones for Persephona edwardsii between the
type locality, Panama, and Punta Piaxtla, Mex-
ico (Garth, 1946). The new species of Clythro-
cerus described below fills a hiatus in the distri-
bution of that genus in the eastern Pacific, where
it is now represented by C. planus off southern
California-northern Lower California, C. lami-
natus in the Galapagos Islands, and the new
species off Central America.
Species collected by the “Zaca” that occur
also in the Atlantic are Cycloes bairdii and
Ethusa mascarone (the americana form). Species
for which Rathbun (1937, p. 5) recognized At-
lantic analogues are Dromidia laraburrei ( D .
antillensis) ; Hypoconcha panamensis ( H . arcu-
ata) ; Ethusa mascarone panamensis (E. m.
americana) , E. lata (E. microphthalma) ; Ebalia
magdalenensis (E. cariosa); Uhlias ellipticus (U.
limbatus) ; llicantha hancocki (/. liodactylus) , /.
1966]
3
Garth: Oxystomatous and Allied Crabs
cedros isu
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EASTERN PACI F1C
EXPEDITIONS
NEW YORK
ZOOLOGICAL SOCIETY
SHORE
COLLECTING STATIONS
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PIEDRA BLANCA B.'
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Text-fig. 1. Shore collecting stations of the Eastern Pacific Expeditions of the New York Zoological
Society. For exact locations of associated dredge stations, refer to Zoologica, vol. XXII, no. 2, and vol.
XXIII, no. 14.
schmitti {I. sparsa); Calappa convexa ( C . flam-
mea), C. saussurei (C. angusta) ; Hepatus koss-
manni ( H . princeps). The writer would propose
the pairing O. sona ( O . antillensis ) rather than
the suggested O. galapagensis (O. antillensis) on
geographical as well as morphological grounds.
The genus Hepatella is restricted to the west
coast of America; the relationships of Dyno-
mene, Lithadia, and Mursia are with the Indo-
west Pacific.
Systematic Considerations
The 28 species of oxystomatous and allied
crabs here reported may be divided as follows: of
the subsection Dromiacea, superfamily Dromi-
idea, 3 species, of which 2 belong to the family
Dromiidae and one to the family Dynomenidae;
of the subsection Oxystomata 25 species, of
which 4 belong to the family Dorippidae (in-
cluding the new Clythrocerus) , 12 to the family
Leucosiidae, and 9 to the family Calappidae. Of
the Leucosiidae, the genus Randallia is repre-
sented by 4 species, the genera Persephona and
lliacantha by 2 each, while of the Calappidae the
genus Osachila is represented by 3 species, the
genus Calappa by 2. Such extensive sympatry is
4
Zoologica: New York Zoological Society
[51: 1
indicative of a multiplicity of ecological niches
among which the dredge as a collecting tool fails
to discriminate.
Species reported for the first time since the
types are the leucosiid Randallia minuta and the
calappid Osachila sona. Described as new to
science is the dorippid Clythrocerus edentatus,
which like its congeners has the last two pairs of
walking legs modified for carrying a fragment
of shell as covering. Because of the excellent
systematic treatment provided by Rathbun
( 1937) and the well defined generic limits with-
in the group, no new combinations are required.
The synonymy used is largely that of Rathbun.
Restriction of Synonymies
Following the format established in the earlier
parts of this series, the synonymies are restricted
to ( 1 ) the original description, (2) the first use
of the name in present combination, and (3)
the citation placing the species within the terri-
tory considered, if not included in the above
two. Reference is made to the Rathbun (1937)
monograph as containing the complete syno-
nymy, and to any reported occurrence since that
date, to and including Garth (1961a).
Explanation of Measurements
Standard measurements are those of length
and breadth of carapace. Length does not in-
clude the posterior spine of the Leucosiidae. In
the case of Mursia of the Calappidae breadth is
given both with (and without) the lateral spine.
Acknowledgment
In addition to those to whom gratitude was
expressed in the earlier reports of this series, the
writer is indebted to the late Dr. Norman T.
Mattox for the identifications of the pelecypod
shells used as covering by Hypoconcha pana-
mensis and to Mr. Timothy Wyatt for preparing
the illustration of the Clythrocerus species.
Systematic Discussion
Section Brachyura
Subsection Dromiacea
Superfamily Dromiidea
Family Dromiidae
Dromidia larraburei Rathbun
Dromidia sarraburei Rathbun, 1910, p. 553, pi.
48, fig. 4. (Error for larraburei) .
Dromidia larraburei, Schmitt, 1921, p. 183, pi.
33, fig. 1. Rathbun, 1937, p. 35, text-fig. 13,
pi. 7, figs. 4, 5, synonymy. Crane, 1937, p.
106. Garth, 1946, p. 346, pi. 61, figs. 1, 2.
Range-. From Monterey Bay, California, to
Sechura Bay, Peru. Galapagos Islands. Shore to
60 fathoms. (Garth).
Material examined : SE of Cedros Island,
Lower California, Mexico, November 10, 1937,
Station 126, D-19, 25 fathoms, 1 male.
Measurements : Male specimen, length 18.6
mm., width 19.4 mm.
Habitat-. Rocks, algae.
Color in life : Buff. Chelae tipped with coral
red. Eyes black; 2 black spots side by side on
intestinal region. (J. Crane, field notes).
Remarks: The specimen, which was kept in
an aquarium, was dead the next morning. (J.
Crane, field notes).
Hypoconcha panamensis Smith
Hypoconcha panamensis Smith, 1869, p. 249.
Rathbun, 1937, p. 47, pi. 9, figs. 6, 7. Garth,
1946, p. 348, pi. 61, figs. 3, 4; 1948, p. 16;
1961a, p. 121.
Range: From Rocky Point (Punta Penasco),
Gulf of California, Mexico (Garth, 1961a), to
Matapalo, Peru. Galapagos Islands. 3-100 fath-
oms. (Garth, 1948).
Material examined: 9 specimens from 4 sta-
tions:
Mexico
Manzanillo, November 22, 1937, Station 184,
D-l, 25 fathoms, 2 males.
Costa Rica
Port Parker, Station 203, January 20, 1938,
D-2, D-3, 10-12 fathoms, 2 males; January 22,
1938, D-9, 1.5-4 fathoms, coral, 1 female.
Cedro Island, Gulf of Nicoya, February 13,
1938, Station 213, D-l to D-10, 4-10 fathoms,
1 male.
Panama
Hannibal Bank, March 20, 1938, Station 224,
D-3, 35 fathoms, 2 males, 1 female.
Measurements: Males from 6.6 X 6.4 to 27.2
X 28.1 mm., females from 6.4 X6.7 mm. to a
size comparable to the largest male, but unmeas-
urable because of its soft-bodied condition.
Habitat: Sand, mud; shelly sand, shelly mud;
crushed shells; algae; coral.
Color in life: Of Manzanillo, Mexico, males:
1966]
Garth: Oxystomatous and Allied Crabs
5
Above and below white mottled with pink; pile
buff. (J. Crane, field notes).
Remarks'. The pink mottling of the crabs
themselves resembled the patches of coralline
algae found on their shell covers. The pelecypod
shells inhabited by the Manzanillo and Hannibal
Bank specimens were preserved and have been
identified by Dr. Norman T. Mattox as Glycy-
meris multicostata (Sowerby) and Papyridea
aspera (Sowerby), respectively.
Family Dynomenidae
Dynomene Ursula Stimpson
Dynomene Ursula Stimpson, 1860, p. 239. Rath-
bun, 1937, p. 54, pi. 12, figs. 1-4. Garth, 1946,
p. 349, pi. 61, figs. 5, 6; 1948, p. 16; 1961a,
p. 121. Schmitt, 1939, p. 25.
Range: From Espiritu Santo Island, Gulf of
California, Mexico (Garth, 1961a), to La Plata
Island, Ecuador. Galapagos Islands. Shore to 70
fathoms. (Garth, 1948).
Material examined : 2 specimens from as many
stations:
Mexico
3 mi. off Pyramid Rock, Clarion Island, May
12, 1936, Station 163, D-2, 55 fathoms, 1 fe-
male.
Panama
Hannibal Bank, March 20, 1938, Station 224,
D-l to D-3, 40-35 fathoms, 1 female.
Measurements : Females 5.8 X 7.6 and 7.1
X 8.2 mm.
Habitat: Rocks, dead coral; mud, sand, shells.
(The former more probable.)
Remarks: Since this species is invariably as-
sociated with rocky shore or coral, it is believed
that the bottom data for D-l and D-2 of Station
224 apply, rather than those of D-3. The bottom
type of Station 163 is not given.
Subsection Oxystomata
Family Dorippidae
Ethusa mas carome panamensis Finnegan
Ethusa mascarone americana, Rathbun, 1898,
p. 615. Not E. americana A. Milne Edwards.
Ethusa mascarone var. panamensis Finnegan,
1931, p. 616.
Ethusa mascarone panamensis, Rathbun, 1937,
p. 79, pi. 22, fig. 1, pi. 23, fig. 1.
Range: From Isabel Island, Mexico, to La
Libertad, Ecuador. Low tide to 25 fathoms.
(Rathbun, 1937).
Material examined: 15 specimens from 10 sta-
tions:
Mexico
Manzanillo, November 22, 1937, Station 184,
D-2, 30 fathoms, 1 male.
Port Guatulco, December 4, 1937, Station
195, D-2, 3 fathoms, 1 male.
Tangola-Tangola Bay, December 12, 1937,
Station 196, D-14, 5 fathoms, 1 male.
El Salvador
Meanguera Island, Gulf of Fonseca, Decem-
ber 23, 1937, Station 199, D-l, 16 fathoms, 3
females (1 ovigerous).
Nicaragua
Corinto, Station 200, December 29, 1937,
D-l, 6.5 fathoms, 1 male; lanuary 7, 1938,
D-27, 3 fathoms, 1 male.
Costa Rica
Port Parker, January 22, 1938, Station 203,
D-ll, 2-4 fathoms, 1 ovigerous female.
Murcielago Bay, January 23, 1938, Station
204, D-4, 2 fathoms, 1 male.
Piedra Blanca Bay, February 5, 1938, Station
208, [D-l to D-10], [2-6 fathoms], 1 male.
Cedro Island, Gulf of Nicoya, February 13,
1938, Station 213, D-l to D-10, 4-10 fathoms,
2 females, 1 young.
Golfito, Gulf of Dulce, March 9, 1938, Sta-
tion 218, D-4, 6 fathoms, 1 young.
Measurements: Males from 4.9 X 4.0 to 9.4
X 8.4 mm., females from 5.7 X 5.1 to 9.2 X
8.3 mm., ovigerous female 7.8 X 7.0 mm.,
young from 3.3 x 2.9 mm.
Habitat: Sand, often with mud and crushed
shell; mangrove leaves; rocks, sand, and algae.
Sand appears the common constituent, as was
mud with Ethusa lata.
Breeding: Costa Rica in late January.
Remarks: In the few instances in which young
and adults occur in the same lot, as at Cedro Is-
land, Gulf of Nicoya, it was noted that the larger
specimens had the exorbital spine directed
obliquely outward and that in at least one speci-
men it was as long as any of the frontal spines,
or, typically Ethusa mascarone americana A.
Milne Edwards. When it is recalled that Finne-
gan’s specimen measured only 5.0 X 4.0 mm.
and was therefore probably immature, it seems
advisable either that the two presently recog-
nized subspecies should be redefined on other
characters, or that only one subspecies of Ethusa
mascarone should be recognized from the east-
ern Pacific. The male from Corinto was particu-
larly granulate on the protuberances of the cara-
pace, and males of 5.8 mm. length and over
showed unequal chelae.
6
Zoologica: New York Zoological Society
[51: 1
Ethusa lata Rathbun
Ethusa lata Rathbun, 1893, p. 258; 1937, p.
84, text-fig. 19, pi. 24, fig. 1, pi. 25, fig. 1, pi.
28, fig. 3. Crane, 1937, p. 105. Garth, 1946,
p. 352, pi. 60, fig. 3; 1948, p. 17.
Range : From Cedros Island, west coast of
Lower California, and San Felipe Bay, Gulf of
California, Mexico, to La Plata Island, Ecuador.
Galapagos Islands. 2-100 fathoms. (Garth,
1948).
Material examined : 18 specimens from 5 sta-
tions.
Mexico
17 mi. SE X E of Acapulco, November 29,
1937, Station 189, D-4, 28 fathoms, 1 female.
Port Guatulco and Santa Cruz Bay, Decem-
ber 7, 1937, Station 195, D-19 to D-21, 17-23
fathoms, 2 males, 2 females.
Tangola-Tangola Bay, December 13, 1937,
Station 196, D-17, 23 fathoms, 3 males, 6 fe-
males.
Costa Rica
Port Parker, January 20, 1938, Station 203,
D-2, D-3, 10-12 fathoms, 2 males, 1 female.
Port Culebra, January 30, 1938, Station 206,
D-l, D-3, 14 fathoms, 1 female.
Measurements : Males from 5.3 X 5.5 to 10.3
X 11.2 mm., females from 4.9 X 5.1 to 15.0 X
17.0 mm., the latter post-ovigerous.
Habitat-. Mud, sandy mud, gravelly mud; shel-
ly sand; crushed shell; algae.
Color in life: Of Port Guatulco, Mexico, male:
Brownish gray. (J. Crane, field notes).
Of Gulf of Fonseca, El Salvador, females:
Cream mottled with brown; eggs crimson. (J.
Crane, field notes) .
Breeding: El Salvador in late December.
Remarks: The 15.0 X 1 7.0 mm. female, while
of good size, is not as large as the 26 X 29 mm.
female type of Aethusa pubescens Faxon, a syn-
onym of Ethusa lata Rathbun. A female of 9.9
X 10.4 mm. dimensions was also noted as having
borne ova. The variety of habitats shown above
is perhaps misleading. Mud was the common
constituent of all bottoms on which E. lata was
dredged. For color, food, and breeding see
Crane (1937).
Ethusa eiliatifrons Faxon
Ethusa eiliatifrons Faxon, 1893, p. 159; 1895,
p. 34, pi. 5, figs. 3, 3a, 3b. Rathbun, 1937, p.
88, text-fig. 20, pi. 24, fig. 2, pi. 25, fig. 2,
pi. 28, fig. 4. Garth, 1961a, p. 121 (by error
Ethusina eiliatifrons on p. 120).
Range: Bay of Panama, 127-259 fathoms.
(Faxon, 1893). Off Rio San Lorenzo, Gulf of
California, 42-48 fathoms. (Garth, 1961a).
Material examined : Off Ballenas Bay, Gulf of
Nicoya, Costa Rica, February 25, 1938, Station
213, D-l 5, D-l 6, 40-45 fathoms, 2 males, 1 fe-
male.
Measurements: Males 13.8 X 14.7 and 20.6
X 22.5 mm., female 25.3 X 28.3 mm.
Habitat: Mud bottom.
Remarks: The specimens are of goodly size
as compared with specimens of Ethusa lata and
E. mascarone panamensis. None is as large, how-
ever, as the 26.5 X 29.5 mm. male cotype
(M.C.Z. No. 4498). Apart from a single record
from the Gulf of California resulting from the
Vermilion Sea Expedition of the Scripps Insti-
tution of Oceanography (Garth, 1961a), the
species has not been reported since the type
specimens were obtained by the “Albatross” in
1891. The “Zaca” Expedition and the Vermilion
Sea Expedition records are from comparable
depths and together extend the bathymetric
range from the 127-259 fathoms of the “Alba-
tross” stations shoalward to the 40-48 fathom
bracket.
Clythroeerus edentatus, new species
Text-fig. 2
Type: Male holotype, A.H.F. No. 378, and
two male paratypes, N.Y.Z.S. No. 37,691, from
Meanguera Island, Gulf of Fonseca, El Salva-
dor, December 23, 1937, “Zaca” Station 199,
D-l, 16 fathoms.
Measurements: Male holotype, length includ-
ing frontal teeth 3.8 mm., without frontal teeth
3.4 mm., width 4.1 mm., exorbital width 2.6
mm., length of chela (lower margin) 3.0 mm.,
length of dactyl 2.2 mm., height of palm 2.0 mm.
Diagnosis: Carapace wider than long. No lat-
eral tooth or spine. Propodal finger of cheliped
truncated, dactylar finger strongly curved down-
ward.
Description: Carapace broader than long even
when frontal teeth are included. Dorsal surface
flattened medially, gently sloping laterally
towards postlateral margins, granulate only at
edges; furrows, with the exception of those out-
lining cardiac region, obliterated. Frontal teeth
narrow, inner margins convex, outer margins
concave, tips rounded, inclining outwards, the
quadripartite extension of the buccal frame vis-
ible in the U-shaped hiatus between. Inner or-
bital margin continuous with broadly curving
front, obliterating inner orbital tooth; outer or-
bital tooth acute, an open fissure between. Lat-
eral margins irregularly scalloped anteriorly, a
suggestion of an indentation, but no tooth, at
1966]
Garth: Oxystomatous and Allied Crabs
7
b
d
Text-fig. 2. Clythrocerus edentatus, male holotype; a, dorsal view; b, abdomen; c, right cheliped; d, left
outer maxilliped. Timothy Wyatt, del. (Scale of a, 2 mm.; scale of b, c, and d, 1 mm.).
widest portion of carapace. Pterygostomian
region sharply granulate; an infraorbital spine
or tooth.
Chelipeds massive, subequal, carpus broader
than long, outer margin rectangular, inner mar-
gin bearing a blunt tooth. Chelae swollen, palms
widening distally, lower margin straight or slight-
ly sinuous, inner surface concave, upper surface
at right angles to outer, marked by a low ridge
with a proximal tubercle, a similar ridge, inflated
proximally, on outer surface. Fixed finger stout,
truncated, occupying two-thirds height of palm,
minutely denticulate, and closing with two or
three basal denticles overlapping base of mov-
Zoologica: New York Zoological Society
[51: 1
able finger, which is slender, denticulate, and
strongly bent downward.
External maxillipeds with meri narrowing an-
teriorly and forming with the similarly atten-
uated epistome a projection visible dorsally be-
tween the rostral teeth.
Third visible segment of male abdomen tri-
partite in dorsal view and ornamented with sharp
granules. The female of the species is unknown.
Remarks : The new species differs from all
other American species of Clythrocerus in hav-
ing no lateral spine or tooth. It differs from C.
laminatus Rathbun of the Galapagos Islands
(see Garth, 1946, pi. 50) in having the frontal
teeth slender instead of broad, their tips rounded
instead of sub-acute, the orbits internally con-
fluent with the front instead of presenting a
small, rectangular inner orbital tooth, the inner
carpal projection of the cheliped a blunt tooth
instead of a rectangular plate, the propodal fin-
ger truncated instead of attenuated and of equal
length to the dactylar finger, and the latter curved
strongly downward instead of only slightly so.
The new species also fills a gap in the eastern
Pacific distribution of the genus, no member of
which has been reported heretofore from along
the Central American mainland coast. It is the
second new species to have come from Station
199, the other being Heterocrvpta craneae
(Garth, 1959).
Family Leucosiidae
Ebalia magdalenensis Rathbun
Ebalia magdalenensis Rathbun, 1933, p. 334, pi.
22; 1937, p. 128, text-fig. 34, pi. 35, figs. 4, 5.
Garth, 1961a, p. 121.
Range : From Scammon Lagoon, Lower Cali-
fornia, and Rocky Point (Punta Penasco), Gulf
of California, Mexico (Garth, 1961a), to La
Libertad, Ecuador. 2-18 fathoms. (Rathbun,
1937).
Material examined : 5 specimens from 2 sta-
tions:
Costa Rica
Port Parker, January 20, 1938, Station 203,
D-2, D-3, 12 fathoms, 1 male, 1 female.
Cedro Island, Gulf of Nicoya, February 13,
1938, Station 213, D-l to D-10, 8 fathoms, 1
male, 2 females.
Measurements'. Males from 6.0 X 6.0 to 7.8
X 7.6 mm., females from 5.6 X 5.7 to 8.3 X
8.5 mm.
Habitat'. Shelly mud; mud, sand, and crushed
shell.
Remarks'. Specimens from Port Parker were
collected in the same dredge hauls with Lithadia
cumingii Bell. Specimens from Cedro Island,
Gulf of Nicoya, are more granulate than Port
Parker specimens, especially on the ridges of the
carapace and on the legs.
Lithadia cumingii Bell
Lithadia cumingii Bell, 1855, p. 305, pi. 33, figs.
6, 7. Rathbun, 1937, p. 136, pi. 38, figs. 1, 2,
7-15. Crane, 1937, p. 102. Garth, 1946, p.
356, pi. 62, fig. 1; 1961a, p. 121.
Range: From Magdalena Bay, Lower Cali-
fornia, and George Island, Gulf of California,
Mexico (Garth, 1961a), to La Plata Island,
Ecuador. Galapagos Islands. 2-51 fathoms.
Material examined: 6 specimens from 3 sta-
tions.
Mexico
Manzanillo, November 22, 1937, Station 184,
D-2, 30 fathoms, 1 male, 2 females (1 ovigerous).
El Salvador
Meanguera Island, Gulf of Fonseca, Decem-
ber 23, 1937, Station 199, D-l, 16 fathoms, 1
male.
Costa Rica
Port Parker, January 20, 1938, Station 203,
D-2, D-3, 12 fathoms, 1 male, 1 female.
Measurements: Males from 7.8 X 8.6 to 12.3
X15.2 mm., females from 3.9 X 4.7 (young) to
12.8 X 16.5 mm., ovigerous female 12.0 X 14.8
mm.
Habitat: Gravelly sand; shelly mud; sand,
mud, and crushed shell.
Color in life: Of Manzanillo, Mexico, speci-
mens: Buffy brown; rostral region darker; eggs
coral red. (J. Crane, field notes).
Of Gulf of Fonseca, El Salvador, male: Brown
blotched with black; chelipeds brown except
abruptly black manus. Ambulatories and under-
parts black. (J. Crane, field notes).
Breeding: West coast of Mexico in late No-
vember.
Uhlias ellipticus Stimpson
Uhlias ellipticus Stimpson, 1871, p. 117, Rath-
bun, 1937, p. 149, pi. 36, figs. 1, 2. Garth,
1946, p. 357, pi. 60, figs. 4, 5.
Range: From San Jose Island, Gulf of Cali-
fornia, Mexico, to Panama. Galapagos Islands.
Intertidal. (Garth, 1946).
Material examined: Port Guatulco, Mexico,
December 6, 1937, Station 195, D-15, diving,
1.5 fathoms, 1 male, 1 female.
Measurements: Male 4.4 X 6.7 mm., female
4.4 X 6.75 mm.
1966]
Garth: Oxystomatous and Allied Crabs
9
Habitat : From coral obtained by diving.
Remarks'. This diminutive species has not
been reported previously from the Mexican
mainland, nor has it been taken previously from
coral.
Persephona edwardsii Bell
Persephona edwardsii Bell, 1855, p. 294, pi. 31,
fig. 8. Rathbun, 1937, p. 154, pi. 45, figs. 3, 4.
Garth, 1946, p. 358; 1961a, p. 121. Not
Boone, 1930, p. 53, fig. A.
Range : From Santa Maria Bay, Lower Cali-
fornia, Mexico (Garth, 1961a), to Cape San
Francisco, Ecuador. 2 fathoms. (Garth, 1946).
Material examined: 12 specimens from 3, or
possibly 4, localities:
Guatemala
7 mi. W. of Champerico, December 15, 1937,
Station 197, D-l, 14 fathoms, 2 males, 1 ovi-
gerous female.
El Salvador
LaLibertad, December 16, 1937, Station 198,
D-l, 13 fathoms, 1 female, 5 young.
Nicaragua
Monypenny Point, Gulf of Fonseca, Decem-
ber 24, 1937, Station 199, D-6, 4 fathoms, 1
female.
lncertae sedis
Locality and date unknown, 1 young male,
soft shell, 1 ovigerous female.
Measurements : Males from 19.5 X 18.3 to
24.5 X 23.5 mm., females from 15.2 X 13.8 to
25.3 X 24.0 mm., ovigerous females from 20.3
X 19.5 (rostrum broken) to 25.3 X 24.0 mm.,
all measurements without posterior spine.
Habitat : Exclusively mud.
Breeding: Guatemala in mid-December.
Remarks: Since the Saboga Island, Panama,
specimens reported by Boone (1930) are of an-
other genus and species (see synonymy for Ilia-
cantha hancocki Rathbun), additional records
for the true Persephona edwardsii from Central
American localities, such as the three above, as-
sume added significance. The two species share
three posterior carapace spines, but here the re-
semblance ceases. The carapace of P. edwardsii
is granulate and the chelipeds relatively massive
as compared to the smooth carapace and attenu-
ated chelipeds of the lliacantha species.
Persephona townsendi (Rathbun)
Myra townsendi Rathbun, 1893, p. 255.
Persephona townsendi, Rathbun, 1898, p. 613;
1937, p. 160, pi. 42, fig. 1, pi. 43, fig. 1. Crane,
1937, p. 104. Garth, 1948, p. 18.
Range: From off Punta San Fermin, Gulf of
California, Mexico, to off Cape Pasado, Ecuador.
2-58 fathoms. (Garth, 1948).
Material examined: 5 specimens from 4 sta-
tions:
Mexico
17 mi. SE x E of Acapulco, November 29,
1937, Station 189, D-4, 28 fathoms, 1 male.
4 mi. SSW of Maldonado Point, November
30, 1937, Station 192, D-l, 26 fathoms, 1 fe-
male.
Costa Rica
Cedro Island, Gulf of Nicoya, February 13,
1938, Station 213, D-l to D-10, 4-10 fathoms,
I young male.
Golfito, Gulf of Dulce, March 9, 1938, Sta-
tion 218, D-8, 6 fathoms, 1 female, 1 young.
Measurements: Males from 10.2 X 9.3 to
15.2 X 14.0 mm., females from 10.4 X 9.8 to
19.9 X 18.9 mm., young from 9.0 X 8.3 mm.,
all measurements without posterior spine.
Habitat: Mud; often with sand, crushed shell,
or mangrove leaves.
Color in life: Of Maldonado Point, Mexico,
male: Carapace cream marbled with red. (J.
Crane, field notes) .
Leucosilia jurinei (Saussure)
Guaia (Ilia) jurinei Saussure, 1853, p. 65, pi. 13,
figs. 4-4b.
Leucosilia jurinii, Bell, 1855, p. 295, pi. 32, fig. 1 .
Leucosilia jurinei, Rathbun, 1910, p. 552, pi. 45,
fig. 1; 1937, p. 170, pi. 48, figs. 1-8. Garth,
1946, p. 358.
Range: From Mazatlan, Mexico, to Sechura
Bay, Peru.
Material examined: 16 specimens from 3, and
possibly 4, localities:
Nicaragua
Castenones, near Corinto, January 5, 1938, 1
ovigerous female.
Costa Rica
Port Parker, January 13, 1938, shore, 3 males,
1 female.
Panama
Bahia Honda, March 16, 1938, 7 males, 3
ovigerous females.
lncertae sedis
Locality and date unknown, 1 large male, en-
crusted with bryozoans.
Measurements: Males from 8.5 X 7.8 to 20.4
10
Zoologica: New York Zoological Society
[51: 1
X19.6 mm., females from 7.3 X 7.2 to 18.1 X
16.4 mm., ovigerous females same.
Breeding : Nicaragua in early January, Pan-
ama in mid-March.
Habitat : Since no mention is made of depth
with any specimen, it is assumed that the speci-
mens listed above were collected ashore. That
Leucosilia jurinei is not strictly an intertidal
species, however, is attested by specimens from
Sechura Bay, Peru, in Hancock collections that
were taken in 9.5 fathoms.
Randallia ornata (Randall)
Ilia ornata Randall, 1839, p. 129.
Randallia ornata, Stimpson, 1857, p. 85. Rath-
bun, 1937, p. 172, pi. 49, figs. 1, 2, and syno-
nymy. Not R. ornata, Boone, 1930, p. 59, pi.
12.
Range : From Mendocino County, California,
to Magdalena Bay, Lower California, Mexico.
5.5-51 fathoms. (Rathbun).
Material examined : Eof Cedros Island, Lower
California, Mexico, March 27, 1936, Station
126, D-l to D-7, 38-48 fathoms, 1 female.
Measurements'. Female specimen, length 21.6
mm., width 20.1 mm., without spines.
Habitat: Not given.
Color in life: Carapace pale buff mottled heav-
ily with vinaceous purple (Ridgway : bordeaux) .
Mottling heaviest on posterior gastric and upper
branchial regions, almost absent on intestinal
[region]. Mottling interspersed with fine apricot
buff dots; these dots also present on intestinal
[region]. Basal three-fourths of merus of chel-
iped solid apricot buff, a large bordeaux splotch
at distal upper end of merus. Carpus, manus,
and dactylus white with a fine dusting of purplish
and buff on upper surface of carpus and manus.
Legs white except for purple patch at distal up-
per end of each merus. Underside pure white.
(J. Crane, field notes).
Behavior: When dropped on mud in an aqua-
rium, [the crab] immediately dug itself in, sink-
ing [its] hind end first, then pressing [its] anterior
portion and chelipeds under until the rostral re-
gion [was] completely covered. Then emerged
the rostrum and the eyes, the former remaining
mud covered because of the fine granules in this
region. (J. Crane, field notes).
Remarks: Of the several Randallia species
taken by the “Zaca,” R. ornata alone is temper-
ate, not tropical, allying itself with the fauna of
California-Lower California, and having as its
Gulf of California cognate R. angelica Garth.
The record of Boone (1930) from Punta Arenas,
Costa Rica, is in error. (See synonymy under
R. bulligera Rathbun).
Randallia bulligera Rathbun
Randallia bulligera Rathbun, 1898, p. 614, pi.
44, fig. 6; 1937, p. 176, text-fig. 38, pi. 50,
figs. 1, 2.
Randallia ornata, Boone, 1930, p. 59, pi. 12. Not
R. ornata Randall.
Range: From Magdalena Bay, Lower Cali-
fornia, Mexico, to Callao, Peru. 2-28 fathoms.
Material examined : 66 specimens from 5 sta-
tions:
Mexico
Port Guatulco, December 7, 1937, Station
195, B-19, 17 fathoms, 1 male, 9 young; D-21,
Santa Cruz Bay, 18 fathoms, 1 male, 26 young.
Tangola-Tangola Bay, Station 196, December
9, 1937, D-6, 7 fathoms, 1 ovigerous female;
December 13, 1937, D-16, 16 fathoms, 2 males,
2 females; D-17, 23 fathoms, 1 female, 3 young.
Guatemala
7 mi. E of Champerico, December 15, 1937,
Station 197, D-l, 14 fathoms, 2 males, 3 ovi-
gerous females; D-2, 14 fathoms, 3 males, 1 ovi-
gerous female.
El Salvador
La Libertad, December 16, 1937, Station 198,
D-l, 13 fathoms, 1 male; D-2, 14 fathoms, 1
male, 1 female.
Meanguera Island, Gulf of Fonseca, Decem-
ber 23, 1937, Station 199, D-l, 16 fathoms, 3
males, 6 females (4 ovigerous).
Measurements: Males from 5.8 X 5.5 to 12.5
X 11.8 mm., females from 7.1 X 6.8 to 12.4 X
12.0 mm., ovigerous females from 7.1 X 6.8 to
10.8 X 10.6 mm., young from 2.7 X 2.7 mm.
Habitat: Predominantly mud; occasionally
with sand or crushed shell.
Color in life: Of Gulf of Fonseca, El Salvador,
specimens: Brightest burnt orange with rose red
tubercles, under parts and distal part of chelae
white. Other specimens paler, buff with deeper
buff or pink tubercles. Eggs scarlet orange. Crane
(field notes) adds that the difference between
bright and pale specimens is not due to sex, there
being bright and pale specimens of both sexes.
Breeding: Mexico, Guatemala, and El Salva-
dor, early to late December.
Remarks: The smallest specimens, including
ovigerous females, were found at the most south-
erly locality, the largest at the most northerly.
Young have erect granules that are almost spin-
ules; old specimens are bryozoan encrusted.
Randallia agaricias Rathbun
Randallia agaricias Rathbun, 1898, p. 614, pi.
44, figs. 7, 7a; 1937, p. 178, text-fig. 40, pi. 50,
1966]
Garth: Oxystomatous and Allied Crabs
11
figs. 3, 4. Garth, 1946, p. 359, pi. 62, fig. 2.
Range-. From Thurloe Bay, Lower California,
Mexico, to La Libertad, Ecuador. Galapagos
Islands. 3-55 fathoms. (Garth).
Material examined : 5 specimens from 3 lo-
calities :
Mexico
Magdalena Bay, Lower California, March 29,
1936, 1 ovigerous female.
Costa Rica
Port Parker, Station 203, January 20, 1938,
D-2, D-3, 10-12 fathoms, 2 ovigerous females;
January 22, 1938, D-ll, 2-4 fathoms, 1 female.
Colombia
Gorgona Island, March 31, 1938, Station 232,
D-l, 2-8 fathoms, 1 male.
Measurements: Male 6.7 X 6.4 mm., non-
ovigerous female 7.2 X 7.3 mm., ovigerous fe-
males 6.4 X 6.5 mm. to 7.7 X 7.7 mm.
Habitat: Shelly sand, mud, algae; rocks; sand.
Breeding: Lower California and Colombia in
late March; Costa Rica in late January.
Remarks: “Zaca” specimens lack the mush-
room tubercles said by Rathbun to be character-
istic but agree with specimens in Hancock col-
lections reported by her as of this species.
Randallia minuta Rathbun
Randallia minuta Rathbun, 1935, p. 2; 1937, p.
179, pi. 84.
Range: From Puerto Culebra, Costa Rica, to
Secas Islands, Panama. 10-15 fathoms.
Material examined: Piedra Blanca Bay, Costa
Rica, February 5, 1938, Station 208, D-[l to 10],
[2-6 fathoms], 1 female.
Measurements: Female specimen, length 4.3
mm., width 4.1 mm.
tiabitat: Rocks, sand, algae.
Remarks: The specimen above is the first to
be recorded since the male type and an ovi-
gerous female were obtained in 1934 by the
Velero III. A slight clarification of the type lo-
cality as recorded by Rathbun ( 1935) should be
made: the “isles in bay” around which dredging
was done at Puerto Culebra by the Velero 111
were the South Viradores Islands; the depth of
Station 257-34 was 10 fathoms.
Iliacantha hancocki Rathbun
Iliacantha hancocki Rathbun, 1935, p. 2; 1937,
p. 187, pi. 57, figs. 1, 2. Garth, 1948, p. 18.
Persephona edwardsii, Boone, 1930, p. 53, fig. A.
Not P. edwardsii Bell.
Range: From Santa Maria Bay, Lower Cali-
fornia, Mexico, to Cape Santa Elena, Ecuador.
5-40 fathoms. (Garth, 1948).
Material examined: 12 specimens from 6 sta-
tions:
Mexico
4 mi. SSW of Maldonado Point, November
30, 1937, Station 192, D-l, 26 fathoms, 1 male.
Port Guatulco and Santa Cruz Bay, December
7, 1937, Station 195, D-20, D-21, 23-18 fathoms,
2 ovigerous females.
Costa Rica
Port Parker, January 20, 1938, Station 203,
D-2, D-3, 10-12 fathoms, 3 young.
Off Ballenas Bay, Gulf of Nicoya, February
25, 1938, Station 213, D-15, D-16, 40-45 fath-
oms, 1 male, 1 female; D-17, 35 fathoms, 1 male.
14 mi. S x E of Judas Point, March 1, 1938,
Station 214, D-l, D-3, D-4, 42-61 fathoms, 1
male, 1 female.
Panama
Gulf of Chiriqui, March 13, 1938, Station
221, D-4, 38 fathoms, 1 female.
Measurements: Males from 18.3 X 15.6 to
32.9 X 28.1 mm., females from 15.3 X13.2 to
33.0 X 29.1 mm., ovigerous females 28.7 X 25.5
and 29.0 X 25.7 mm., young from 5.8 X 5.2
mm. All measurements without posterior spine.
Habitat: Mud; shelly sand, mud, algae; mud,
shell, rocks.
Color in life: Of Maldonado Point, Mexico,
male; Regular coloring. (J. Crane, field notes).
This may refer to absence of pattern. ( J. G.) .
Breeding: West coast of Mexico in early De-
cember.
Remarks: The above series contains speci-
mens of both sexes of a size larger than the 23.4
X 20.6 male holotype, the only specimen of
which measurements are given by Rathbun
(1937).
Iliacantha schmitti Rathbun
Iliacantha schmitti Rathbun, 1935, p. 2; 1937,
p. 192, text-fig. 42, pi. 83, figs. 1, 2. Garth,
1961a, p. 121.
Range: From Point Tosco, Lower California,
and Angel de la Guarda Island, Gulf of Cali-
fornia, Mexico (Garth, 1961a), to La Plata Is-
land, Ecuador. 10-150 fathoms. (Rathbun,
1937).
Material examined: 4 specimens from 2 sta-
tions.
Costa Rica
14 mi. S x E of Judas Point, March 1, 1938,
Station 214, D-l, D-3, D-4, 42-61 fathoms, 2
females.
12
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[51: 1
Panama
Hannibal Bank, March 20, 1938, Station 224,
D-3, 35 fathoms, 1 male, 1 female.
Measurements'. Male 33.1 X 29.8 mm., fe-
males from 15.0 X13.6 to 32.6 X 29.0 mm. All
measurements without posterior spine.
Habitat : Mud, shell, rocks; sand, shells, algae.
Remarks'. This species and the more abundant
lliacantha hancocki were taken in the same
dredge haul at Hannibal Bank. Of the two spe-
cies, I. schmitti has the more attenuated cheli-
peds, the fingers alone being one and one-half
times the upper margin of the palm. It was noted
that the margin connecting the posterior spines
is visible in dorsal view in the female only, and
not in the male, as would be assumed from the
diagnosis given by Rathbun (1937).
The two localities above are well north of the
Colombia-Ecuador range recorded by Rathbun
(1937) and would represent an outright exten-
sion were it not for the fact that 7. schmitti was
found by Hancock Expeditions to occur exten-
sively in the Lower California-Gulf of California
region (Garth, 1961a). The “Zaca” Expedition
records serve to define the southern portion of
an apparently discontinuous range, and to ex-
tend it northward to Judas Point, Costa Rica.
Family Calappidae
Calappa convexa Saussure
Calappa convexa Saussure, 1853, p. 362, pi. 13,
fig. 3. Rathbun, 1937, p. 206, pi. 52, figs. 1-3.
Garth, 1946, p. 360, pi. 62, fig. 6; 1948, p. 19.
Range: From Magdalena Bay, Tower Cali-
fornia, Mexico, to Santa Elena Bay, Ecuador.
Galapagos Islands. 0-32 fathoms. (Garth, 1948).
Material examined : 5 specimens from 4 sta-
tions:
Mexico
Port Guatulco, December 6, 1937, Station
195, D-10, D-ll, 4-5 fathoms, 1 young.
Tangola-Tangola Bay, December 9, 1937, Sta-
tion 196, D-6, 7 fathoms, 1 young.
Costa Rica
Port Parker, January 22, 1938, Station 203,
D-10, 6-2.5 fathoms, 1 female, 1 young.
Piedra Blanca Bay, February 5, 1938, Station
208, dredges [D-l to D-10], 2-6 fathoms, 1
young.
Measurements'. Female specimen 19.3 X 24.5
mm. Young from 4.5 X 5.0 to 9.8 X 1 1.3 mm.
Habitat : Gravelly sand, crushed shell, dead
coral; rocks, sand, and algae. Fairly common in
12 feet on sand near rocks, according to pilot.
Natives catch in hands by diving. Good to eat.
(J. Crane, field notes).
Color in life: Lavender spotted finely with
white. Inside of cheliped orange. Ambulatories
and chelipeds spotted with yellow and mottled
with white and lavender. (J. Crane, field notes,
of large commercial Calappa bought in Aca-
pulco market. Specimen not seen by the writer
but said to be the same as Port Guatulco and
Tangola-Tangola species).
Remarks: Since the young of Calappa con-
vexa are narrow like C. saussurei, rather than
wide like the adults, reliance must be placed on
characters other than relative width to length in
separating immature specimens of the two spe-
cies. Of these the less tuberculate posterior third
of the carapace and lower third of the outer sur-
face of the palm of C. convexa, with granules
horizontally aligned in both instances, proved
most useful.
Calappa saussurei Rathbun
Calappa saussurei Rathbun, 1898, p. 609, pi. 41,
fig. 6; 1937, p. 206, text-fig. 43, pi. 63, figs.
1-4. Finnegan, 1931, p. 611, fig. 1. Crane,
1937, p. 98. Garth, 1948, p. 19; 1961a, p. 121.
Range: From Point Tosco, Lower California,
and Puerto Refugio, Gulf of California, Mexico
(Garth, 1961a), to La Plata Island, Eucador.
7-150 fathoms. (Garth, 1948).
Material examined: 1 1 specimens from 6 sta-
tions:
Mexico
Gorda Banks, Gulf of California, November
13, 1937, Station 150, D-27, 60 fathoms, 1 male,
1 young female.
Manzanillo, November 22, 1937, Station 184,
D-2, 30 fathoms, 2 males.
Nicaragua
Corinto, Station 200, December 29, 1937,
D-4, D-6, 0.5-2. 5 fathoms, 2 young; January 5,
1938, D-15, 1 fathom, 1 young.
Costa Rica
14 mi. S x E of Judas Point, March 1, 1938,
Station 214, D-4, 61 fathoms, 1 male, 1 female.
Panama
Gulf of Chiriqui, March 13, 1938, Station
221, D-3, 35 fathoms, 1 male.
Hannibal Bank, March 20, 1938, Station 224,
D-3, 35 fathoms, 1 female.
Measurements: Males from 23.0 X 27.1 to
34.5 X 42.3 mm., females from 19.2 X 22.3 to
1966]
Garth: Oxystomatous and Allied Crabs
13
34.8 X 42.6 mm. (spines broken), young from
3.8 X 3.9 to 10.2 X 12.0 mm.
Habitat : Sand, gravelly sand; mud, sandy
mud; rocks; sand, shells, algae; mangrove leaves.
Color in life: Of Gorda Banks specimens:
Small specimen: Pale tan, tubercles coral pink.
Large specimen: Pinkish all over; tubercles coral
as above. (J. Crane, field notes).
Of Manzanillo, Mexico, males: Pale phase.
(J. Crane, field notes).
Remarks : For food, breeding, and behavior
see Crane ( 1937, p. 99) .
Mursia gaudichaudii (Milne Edwards)
Platymera gaudichaudii Milne Edwards, 1837,
p. 108.
Mursia gaudichaudii, Schmitt, 1921, p. 190, text-
fig. 118. Rathbun, 1937, p. 220, pi. 66, figs.
1-3, pi. 67, figs. 1-6. Crane, 1937, p. 99. Garth,
1946, p. 361, pi. 62, figs. 3, 4.
Mursia gaudichaudi. Garth, 1957, p. 16, syno-
nymy.
Range: From Gulf of the Farallones, Cali-
fornia, to Talcahuano, Chile. Galapagos Islands.
20-218 fathoms. (Garth, 1957).
Material examined: 2 specimens from as many
stations:
Mexico
E of Cedros Island, Lower California, Mexico,
November 10, 1937, Station 126, D-14, 45 fath-
oms, 1 young female.
Tangola-Tangola Bay, December 13, 1937,
Station 196, D-19, 30 fathoms, 1 male.
Measurements: Male 30.4 X 56.8 (44.0)
mm., young female 11.2 X 15.1 mm. without
lateral spine.
Habitat: Mud, algae.
Color in life: Carapace and chelipeds olive
tan. Tubercles and spines rich chestnut. Under-
parts pure white. Dactyls tipped with coral pink.
(J. Crane, field notes). See also Crane (1937,
p. 100).
Remarks: The species enjoys the greatest lati-
tudinal range of any eastern Pacific brachyuran
and a correspondingly great bathymetric range
as well.
Cyc/oes bairdii Stimpson
Cyclois bairdii Stimpson, 1860, p. 237.
Cycloes bairdii, Rathbun, 1898, p. 610; 1937, p.
225, pi. 69, figs. 3, 4. Finnegan, 1931, p. 613.
Crane, 1937, p. 100. Garth, 1946, p. 362, pi.
62, figs. 7, 8; 1948, p. 19; 1961a, p. 121.
Range: From Santa Maria Bay, Lower Cali-
fornia, and Los Frailes, Gulf of California, Mex-
ico (Garth, 1961a), to La Libertad, Ecuador.
Galapagos Islands. 2-70 fathoms. (Garth, 1948).
Occurs also in the Atlantic.
Material examined: 132 specimens from 10
stations:
Mexico
3 mi. off Pyramid Rock, Clarion Island, May
12, 1936, Station 163, D-2, 55 fathoms, 3 males,
1 female.
Chamela Bay, November 17, 1937, Station
182, D-4, 16 fathoms, 1 male, 1 young.
Tenacatita Bay, November 21, 1937, Station
183, D-l, 15 fathoms, 1 female.
Port Guatulco, Station 195, December 4,
1937, D-3, 3.5 fathoms, 1 young; December 5,
1937, D-6, D-7, D-9, 3 fathoms, 3 young; De-
cember 6, 1937, D-10, D-ll, 4-5 fathoms, 1
male, 1 female, 6 young; December 7, 1937,
D-16, D-17, 6-10 fathoms, 1 male, 5 young;
D-19, 17 fathoms, 1 young.
Tangola-Tangola Bay, Station 196, December
9, 1937, D-l, D-5, D-6, D-8, 5-9 fathoms, 1
male, 23 young; December 12, 1937, D-9 to
D-14, 4.5-10 fathoms, 1 male, 8 young; Decem-
ber 13, D-16, 16 fathoms, 3 males, 3 females,
24 young.
Costa Rica
Port Parker, January 22, 1938, Station 203,
D-4, 7 fathoms, 1 young; D-l 2, 2 fathoms, 1
young female.
Murcielago Bay, January 23, 1938, Station
204, D-l, D-2, D-4, 4-2 fathoms, 5 young.
Port Culebra, January 30, 1938, Station 206,
D-2, 14 fathoms, 1 female, soft shell.
Piedra Blanca, February 5, 1938, Station 208,
[D-l to D-10], 2-6 fathoms, 5 young.
Colombia
Gorgona Island, March 3 1 , 1938, Station 232,
D-l, 2-8 fathoms, 30 young.
Measurements: Males from 11.2 X 11.8 to
31.0 X 32.3 mm., females from 11.7 X 11.8 to
32.3 X 32.8 mm., young from 4.1 X 4.2 mm.
None of the females is ovigerous.
Habitat: Sand, gravelly sand; mud, gravelly
mud, sandy mud; sand or gravel with algae;
crushed shell; dead coral.
Color in life: Of Chamela Bay, Mexico, speci-
mens: General color light chestnut; carpus,
manus, and dactyls of ambulatories of larger
specimen violet. Inner side of carpus, manus,
and dactyls of cheliped streaked with orange and
white in larger specimen; white with single large
orange spot on inside of distal end of manus in
smaller specimen. Underparts white. (J. Crane,
field notes) .
14
Zoologica: New York Zoological Society
[51: 1
Of Port Guatulco, Mexico, young: Mottled
brown and white; chelipeds white. (J. Crane,
field notes) .
Behavior : [When] kept in an aquarium, the
larger [of the two Chamela Bay specimens] never
buried itself; [it] paid no attention to dark, flash-
light, or daylight, [it] scarcely moved but kept
a fine stream of water shooting above its mouth
straight upward to a distance of two and one-half
inches. The smaller occasionally buried itself
half way, hind end first; [it was] much more ac-
tive than the larger. Both merged perfectly with
the coarse sandy bottom with tiny shells. (J.
Crane, field notes).
Remarks : Specimens of both sexes measured
above are larger than the 29 X 29 mm. female
taken by the “Zaca” at Arena Bank, Gulf of Cali-
fornia (Crane, 1937), although not as large as
the 45.8 X 49 mm. female recorded by Rathbun
(1937).
Hepatus kossmanni Neumann
Hepatus kossmanni Neumann, 1878, p. 28.
Hepatus kossmanni, Rathbun, 1910, p. 593, part
(Panama Bay); 1937, p. 239, pi. 72, figs. 3,
4. Crane, 1937, p. 101, pi. 1, figs. 5, 6. Garth,
1948, p. 20; 1961a, p. 121.
Range : From Abreojos Point, west coast of
Lower California, and Angeles Bay, Gulf of
California, Mexico (Garth, 1961a), to La Lib-
ertad, Ecuador. 2-25 fathoms. (Garth, 1948).
Material examined: 14 specimens from 6 sta-
tions:
Mexico
17 mi. SE x E of Acapulco, November 29,
1937, Station 189, D-2, D-4, 20-28 fathoms, 1
male, 3 females.
Tangola-Tangola Bay, December 13, 1937,
Station 196, D-17, 23 fathoms, 1 female, with
rhizocephalan.
Guatemala
7 mi. W of Champerico, December 15, 1937,
Station 197, D-l, D-2, 14 fathoms, 2 females,
4 young.
El Salvador
La Libertad, December 16, 1937, Station 198,
D-l, 13 fathoms, 1 male.
Costa Rica
Cedro Island, Gulf of Nicoya, February 13,
1938, Station 213, D-ll, 8 fathoms, carapace
fragment.
Golfito, Gulf of Dulce, March 7, 1938, depth
not given, 1 male.
Measurements: Males 21.9 X 30.3 to 39.2 X
45.1 mm., females from 13.3 X 19.2 to 35.9 X
48.9 mm., young from 7.7 X 10.8 mm.
Habitat: Exclusively mud.
Color in life: Of Acapulco, Mexico, specimen:
Carapace brown, formed of dark brown, very
fine marblings on cream. Legs banded chestnut
and white. Manus, dactyls, and underparts
white. (J. Crane, field notes).
Remarks: Specimens from near Acapulco and
from Tangola-Tangola Bay, Mexico, carried sea
anemones as commensals. According to Crane
(field notes) the anemone was in the exact cen-
ter of the carapace of the two larger specimens
from station 189. The largest female, also from
this station, was almost smooth, not lumpy as
is usual for the species.
Hepateila arnica Smith
Hepatella arnica Smith, 1869, p. 250, footnote.
Rathbun, 1937, p. 247, pi. 76, figs. 1, 2.
Range: From Isabel Island, Mexico, to Cape
San Francisco, Ecuador. 2-35 fathoms. (Rath-
bun) .
Material examined: Port Guatulco, Mexico,
December 5, 1937, Station 195, D-7, 4.5 fath-
oms, 1 young male.
Measurements: Male 7.8 mm. long, 10.1 mm.
wide.
Habitat: Rocks.
Remarks: A second species, Hepatella peruvi-
ana Rathbun, 1933, occurs with H. arnica in the
southern portion of its range, from Panama to
Ecuador, and continues to Peru. Neither species
is common.
Osachila lata Faxon
Osachila lata Faxon, 1893, p. 159; 1895, p. 32,
pi. 5, figs. 2, 2a, 2b. Rathbun, 1937, p. 257,
fig. 45, pi. 78, figs. 1, 2. Crane, 1937, p. 100
(part: not the ovigerous female from Arena
Bank), pi. 1, figs. 1, 2 (not figs. 3-4).
Range: From Santa Inez Bay, Gulf of Cali-
fornia, to Chamela or Perula Bay, Mexico. 30-
80 fathoms.
Material examined: Manzanillo, Mexico, No-
vember 22, 1937, Station 184, D-2, 30 fathoms,
6 males, 8 females, 1 young.
Measurements: Males from 22.5 X 28.7 to
30.6 X 40.4 mm., females from 18.0 X 23.1 to
25.0 X 31.9 mm., young specimen 7.0 X 8.9
mm.
Habitat: Gravelly sand.
Color in life: General tone . . . burnt sienna;
rostrum, lower manus, fixed dactyl, and under-
parts white. Ambulatories banded chestnut and
white. (J. Crane, field notes).
Remarks: As previously noted (Garth, 1946,
1966]
Garth: Oxystomatous and Allied Crabs
15
p. 366) only the male figured by Crane (1937,
pi. 1, figs. 1, 2) is of this species, the figured
female (Ibid., figs. 3, 4) being of the following
Osachila levis. The figure of the male has particu-
lar value, the specimen having been compared
by Dr. F. A. Chace, Jr. with Faxon’s then unique
type.
Osachila levis Rathbun
Osachila levis Rathbun, 1898, p. 612; 1937, p.
254, pi. 78, figs. 3, 4. Garth, 1946, p. 365, pi.
62, fig. 5; 1961a, p. 121.
Osachila lata , Crane, 1937, p. 100 (part: the
ovigerous female from Arena Bank), pi. 1,
figs. 3, 4. Not O. lata Faxon.
Range : From Puerto Refugio, Gulf of Cali-
fornia, Mexico (Garth, 1961a), to La Plata Is-
land, Ecuador. Galapagos Islands. 12-80 fath-
oms. (Garth, 1946).
Material examined: Hannibal Bank, March
20, 1938, Station 224, D-2, D-3, 35 fathoms, I
male, 6 females (3 ovigerous), 1 young.
Measurements : Male 21.0 X 24.5 mm., non-
ovigerous females from 28.7 X 33.5 to 32.3 X
38.2 mm., ovigerous females from 32.2 X 38.4
to 37.9 X 45.0 mm., young (male) 12.6 X 14.4
mm.
Habitat: Rocks, mud, dead coral; sand, shells,
algae.
Breeding: Three of the six females dredged at
Hannibal Bank were in berry.
Remarks: Specimens of both sexes are con-
siderably larger than the 19 X 21 mm. female
holotype. (See also Remarks under the preceding
and following species).
Osachila so na Garth
Osachila sona Garth, 1940, p. 56, pi. 12, figs. 1-4.
Range: Known only from the vicinity of
Medidor Island, outside Bahia Honda, Panama,
30-50 fathoms. (Garth, 1940).
Material examined: Hannibal Bank, Panama,
March 20, 1938, Station 224, D-2, 35 fathoms, 1
male, 3 females, 1 young.
Measurements: Male 17.2 X 21.5 mm., fe-
males from 30.1 X 37.8 to 35.6 X 46.4 mm.,
young 10.2 X 12.5 mm.
Habitat: Rocks, mud, dead coral. Encrusted
with coralline algae and bryozoans.
Remarks: The three females from Hannibal
Bank are all larger than the 20.0 X 25.5 mm.
female holotype, the single male larger than the
14.0 X 17.3 mm allotype, with which they were
compared. They were segregated from a more
extensive series of Osachila levis Rathbun, found
in the same dredge haul, by their greater pro-
portionate breadth to length, their rougher cara-
pace and dorsal leg surfaces, and their more ad-
vanced and strongly denticulate anterolateral
margins. It was also noted that the two species
were in a different phase of the breeding cycle,
three of the six female O. levis being in berry,
whereas none of the O. sona females carried ova.
To the six points distinguishing Osachila sona
from its nearest relative, O. galapagensis Rath-
bun (Cf. Garth, 1940, p. 58), a seventh should
be added: (7) The dactyls of the ambulatory
legs have paired inferior laminae, while in the
Galapagos species these laminae are lacking.
Literature Cited
Bell, T.
1855. Horae carcinologicae, or notices of Crust-
acea. I. A monograph of the Leucosiadae,
with observations on the relations, struc-
ture, habits, and distribution of the family;
a revision of the generic characters; and
descriptions of new genera and species.
Trans. Linn. Soc. London, vol. 21, pp.
277-314, pis. 30-34.
Boone, Lee
1930. Scientific results of the cruises of the
yachts “Eagle” and “Ara”, 1921-1928,
William K. Vanderbilt, commanding.
Crustacea: Stomatopoda and Brachyura.
Bull. Vanderbilt Mar. Mus., vol. 2, pp.
1-228, pis. 1-74.
Crane, Jocelyn
1937. The Templeton Crocker Expedition. III.
Brachygnathous crabs from the Gulf of
California and the west coast of Lower
California. Zoologica, vol. 22, pp. 47-78,
pis. 1-8.
1947. Intertidal brachygnathous crabs from the
west coast of tropical America with special
reference to ecology. Zoologica, vol. 32,
pp. 69-95, text-figs. 1-3.
Faxon, W.
1893. Reports on the dredging operations off
the west coast of Central America to the
Galapagos, to the west coast of Mexico,
and in the Gulf of California ... by the
U. S. Fish Commission steamer “Alba-
tross,” during 1891 . . . VI. Preliminary
descriptions of new species of Crustacea.
Bull. Mus. Compar. Zool. Harvard, vol.
24, pp. 149-220.
1895. Reports on an exploration off the west
coasts of Mexico, Central and South
America, and off the Galapagos Islands
... by the U. S. Fish Commission steamer
“Albatross,” during 1891 . . . XV. The
stalk-eyed Crustacea. Mem. Mus. Compar.
Zool. Harvard, vol. 18, pp. 1-292, pis.
A-K, 1-56.
16
Zoologica: New York Zoological Society
[51: 1
Finnegan, Susan
1931. Report on the Brachyura collected in Cen-
tral America, the Gorgona and Galapagos
Islands, by Dr. Crossland on the ‘St.
George’ Expedition to the Pacific, 1924-
25. Jour. Linn. Soc. London, Zool., vol.
37, pp. 607-673, text figs. 1-6.
Garth, J. S.
1940. Some new species of brachyuran crabs
from Mexico and the Central and South
American mainland. Allan Hancock Paci-
fic Exped., vol. 5, no. 3, pp. 53-127, pis.
11-26.
1946. Littoral brachyuran fauna of the Galapa-
gos Archipelago. Allan Hancock Pacific
Exped., vol. 5, no. 10, pp. (iv) 341-601,
pis. 49-87, text fig. 1.
1948. The Brachyura of the “Askoy” Expedition
with remarks on carcinological collecting
in the Panama Bight. Bull. Amer. Mus.
Nat. Hist., vol. 92, art. 1, pp. 1-66, pis.
1-8, text figs. 1-5.
1957. Reports of the Lund University Chile Ex-
pedition 1948-1949. No. 29. The Crustacea
Decapoda Brachyura of Chile. Lunds
Univ. Arsskr., n. s., Avd. 2, vol. 53, no. 7,
pp. 1-127, pis. 1-4, text figs. 1-11.
1959. Eastern Pacific Expeditions of the New
York Zoological Society. XLIV. Non-in-
tertidal brachygnathous crabs from the
west coast of tropical America. Part 1:
Brachygnatha Oxyrhyncha. Zoologica, vol.
44, pt. 3, pp. 105-126, pi. 1, text figs. 1, 2.
1961a. The biogeography of Baja California and
adjacent seas. (Symposium.) Distribution
and affinities of the brachyuran Crustacea.
Syst. Zool., vol. 9, pp. 105-123, text figs.
1-3. (Issued January, 1961).
1961b. Eastern Pacific Expeditions of the New
York Zoological Society. XLV. Non-in-
tertidal brachygnathous crabs from the
west coast of tropical America. Part 2:
Brachygnatha Brachyrhyncha. Zoologica,
vol. 46, pt. 3, pp. 133-159, pi. 1, text figs.
1,2.
Milne Edwards, H.
1837. Histoire naturelle des Crustaces, compre-
nant l’anatomie, la physiologie et la classi-
fication de ces animaux. Vol. 2, pp. 1-532.
Paris.
Neumann, R.
1878. Systematische Uebersicht der Gattungen
der Oxyrhynchen. Catalog der Podoph-
thalmen Crustaceen des Heidelberger
Museums. Beschreibung einiger neuer Art-
en. pp. 1-39. Leipzig.
Randall, J. W.
1839. Catalogue of the Crustacea brought by
Thomas Nuttall and J. K. Townsend,
from the west coast of North America and
the Sandwich Islands. Jour. Acad. Nat.
Sci. Philadelphia, vol. 8, pp. 106-147, pis.
3-7.
Rathbun, Mary J.
1893. Scientific results of explorations by the
U. S. Fish Commission steamer Albatross.
XXIV. Descriptions of new genera and
species of crabs from the west coast of
North America and the Sandwich Islands.
Proc. U. S. Nat. Mus., vol. 16, pp. 223-
260.
1898. The Brachyura collected by the U. S. Fish
Commission steamer Albatross on the
voyage from Norfolk, Virginia, to San
Francisco, California, 1887-1888. Proc.
U. S. Nat. Mus., vol. 21, pp. 567-616, pis.
41-44.
1910. The stalk-eyed Crustacea of Peru and
the adjacent coast. Proc. U. S. Nat. Mus.,
vol. 38, pp. 531-620, pis. 36-56.
1933. In: Glassell, S. A., Descriptions of five
new species of Brachyura collected on
the west coast of Mexico. Trans. San
Diego Soc. Nat. Hist., vol. 7, no. 28, pp.
331-344, pis. 22-26.
1935. Preliminary descriptions of seven new
species of oxystomatous and allied crabs.
Proc. Biol. Soc. Washington, vol. 48, pp.
1-4.
1937. The oxystomatous and allied crabs of
America. Bull. No. 166, U. S. Nat. Mus.,
pp. (vi) 1-278, pis. 1-86, text figs. 1-47.
Saussure, H. de
1853. Description de quelques Crustaces nou-
veaux de la cote occidentale du Mexique.
Rev. et Mag. de Zool., ser. 2, vol. 5, pp.
354-368, pis. 12-13.
Schmitt, W. L.
1921. The marine decapod Crustacea of Cali-
fornia. Univ. California Pubs. Zool., vol.
23, pp. 1-470, pis. 1-50, text figs. 1-164.
1939. Decapod and other Crustacea collected
on the Presidential Cruise of 1938. Smith-
sonian Misc. Coll., vol. 98, no. 6, pp. 1-29,
pis. 1-3.
Smith, S. I.
1869. In: Verrill, A. E., On the parasitic habits
of Crustacea. Amer. Nat., vol. 3, pp. 239-
250, text figs. 41-42.
Stimpson, W.
1857. Notices of new species of Crustacea from
western North America; being an abstract
from a paper to be published in the Jour-
nal of the Society. Proc. Boston Soc. Nat.
Hist., vol. 6, pp. 84-89.
1860. Notes on North American Crustacea, in
the Museum of the Smithsonian Institu-
tion. No. II. Ann. Lyceum Nat. Hist. New
York, vol. 7, pp. 176-246, pis. 2, 5.
1871. Notes on North American Crustacea, in
the Museum of the Smithsonian Institu-
tion. iNo. 111. Ann. Lyceum Nat. Hist.
New York, vol. 10, pp. 92-136.
2
Behavior of Infant Rhesus Monkeys and
Their Mothers in a Free-ranging Band
John H. Kaufmann1
Laboratory of Perinatal Physiology, National Institute of Neurological Diseases and Blindness, National
Institutes of Health, Public Health Service, San Juan, Puerto Rico
(Plates I-IV)
Introduction
DESPITE the recent increase in primate
field studies, there is relatively little
known of the early development and
socialization of infant monkeys in free-ranging
populations. Such information is needed for an
understanding of the behavior of primates in the
field, and is highly desirable as a standard of
comparison for the many studies of development
and socialization that are conducted in the phy-
sically and socially restricted environments of
laboratory colonies. For comparison with labo-
ratory studies, information on rhesus monkeys
( Macaca mulatto ) is especially pertinent. Yet
information on the behavior of rhesus infants in
the field has been limited to brief observations
by Southwick, Beg & Siddiqi (1965) in India,
and by Altmann (1962) in the free-ranging col-
ony on Cayo Santiago, a small islet off the east
coast of Puerto Rico (see Altmann’s report for
a description and history of the colony) .
Until recently, study of captive rhesus in-
fants was confined to highly artificial situations
in small indoor cages and “playrooms.” Foley
(1934), Hines (1942), Lashley & Watson
(1913), Mowbray & Cadell ( 1962) , and Tinkle-
paugh & Hartman (1932) all studied the indi-
vidual behavior of infants. Hansen (1962) and
Rosenblum (1961) included limited social inter-
action in their studies, and Harlow, Mason, and
others (summarized by Mason, 1965) have
made extensive studies of deprivation effects on
socialization. Perhaps the most unnatural aspect
of all these studies was the lack or great restric-
tion of social interaction. Although such restric-
Tresent address: Zoology Department, University of
Florida, Gainesville, Florida.
tion is necessary to obtain detailed, analytical
results, it leaves the possibility that the behavior
observed may be different, at least in its rate of
development, from that of free-ranging monkeys
in large groups. Certainly the socialization of
laboratory monkeys fails to include frequent in-
teractions with the many age and sex categories
found in large bands.
In an effort to help bridge the gap between
field and laboratory situations, Hinde, Rowell &
Spencer-Booth (1964) studied the behavior of
rhesus infants living in small social groups in
outdoor runs. Their paper summarizes the re-
sults of previous laboratory studies, and presents
abundant data that are directly comparable with
data taken in the field.
In the course of other field work during the
1963 birth season on Cayo Santiago, I had an
opportunity to observe the behavior of rhesus in-
fants in a large, free-ranging band. This paper
presents data on the behavioral development
and social relations of infants up to three months
old. Because the socialization of infant monkeys
is inextricably bound to the social behavior of
their mothers, the mothers’ social relations dur-
ing this period will also be considered.
Methods
All of the data presented here were obtained
from field observation of the colony’s largest
band during its 1963 birth season, which lasted
from January 7 to May 4. During this period the
band contained 40 mature females, 28 mature
males, 35 immature females (1-3 years old) and
25 immature males. In this band 30 infants were
born naturally on the island: 2 in January, 14 in
February, 10 in March, 2 in April and 2 in May.
17
18
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Four infants were delivered by cesarean section
and taken from their mothers for use in medical
experiments. I determined the social rank of the
mature males and females by observing displace-
ments at food and water, and the exchange of
threatening and submissive signals. All of the
monkeys but the infants were individually recog-
nizable by physical characteristics and tattoos;
the infants were identified by their association
with their mothers.
I recorded as many as possible of the observed
social interactions of infants and of their
mothers, and paid particular attention to the first
dates on which each infant performed significant
new acts. Two females were selected for special
study. One of these (11) was over ten years old
with a long breeding history; the other (DR) was
a four-year-old with her first infant. These two
and their infants were watched for one to two
hours each day, five to six days per week, during
the first month after birth. Thereafter a special
effort was made to observe them as often as
practicable along with the other females and
their infants. Approximately 70 hours were spent
observing the other females and infants. Obser-
vations were made during all of the daylight
hours, but were concentrated during the early
morning when the monkeys were most active.
Because every infant could not be observed con-
tinuously, I undoubtedly missed seeing many
acts when they were first performed. My obser-
vations should, however, give a good idea of
when each new act became common among in-
fants of a certain age.
Behavioral Development of Infants
Table 1 summarizes the infants’ behavioral
development.
A newborn infant typically clung tightly to its
mother’s underside, alternately sleeping and
nursing (Fig. 1). When she walked the infant
remained clinging ventrally by its hands and feet
(Fig. 2), though the mother might help support
it at first with one hand. Infants clung unaided
even when their mothers ran at top speed or
joined in a fight. As early as the second day after
birth some infants began sitting on the ground
and standing shakily on all fours for a few sec-
onds. At first they could hardly lift their heads
and abdomens clear of the ground, but even so
they sometimes crawled a faltering step or two
before collapsing in a heap. Standing and walk-
ing improved rapidly and by the end of the first
week advanced infants were able to walk several
feet, though slowly and clumsily.
In the second week infants began actively ex-
ploring within three feet of their mothers, han-
dling and mouthing plants, sticks and rocks. The
Table 1. Behavioral Development of Infants
Act
First day
ever seen
Week when
first performed
by most infants
Stand on all fours
2
1
Crawl
2
1
Sit upright on ground
4
1
Stand upright (supported)
7
2
Stand upright (unsupported)
26
*
Handle and mouth plants,
sticks, rocks
11
2
Hop (bipedal)
12
2-3
Jump (in trees)
41
7
Hang by legs and feet in
trees
23
*
Climb
On mother
7
1
On vines, bushes and trees
Up to 1 ft.
11
2-3
Up to 3 ft.
16
4-5
10 ft. and above
47
7-8
Follow mother
10 ft.
16
*
30 ft.
29
*
50 ft.
33
*
Ride on mother’s back
4
1-6
*Not seen performed by most infants by end of study.
distances which infants traveled from their
mothers were limited by the restraints imposed
by their mothers more than by the infants’ physi-
cal limitations, and these distances will be given
in the section on infant-mother relations. A bet-
ter indication of the infants’ capabilities is the
distance they walked in following their mothers
when they were not carried. Thus one infant fol-
lowed 10 feet on the 16th day and 30 feet on the
29th day, while two infants followed more than
50 feet at the end of the fifth week.
During the first week some mothers pushed
their infants up onto their backs instead of carry-
ing them below. This happened most often when
the infant was sitting by the mother’s side. At
first the infant rode on her back for only a few
seconds before falling to the ground; soon it
clung precariously as she walked, frequently slip-
ping low on her flank, shoulder or hip. By the
end of the first week some infants rode on top
frequently and adeptly (Fig. 3). In the time of
first riding on their mothers’ backs the infants
were extremely variable. Though some became
skilled during the first week, others did not begin
until the seventh week, and approximately equal
numbers began during each of the intervening
weeks. The range was 4-45 days, the mean 22
days, the median 26 days, and there was no
Kaufmann: Behavior of Infant Rhesus Monkeys
19
1966]
clearly defined mode. Of all my observations of
first dates for specific acts, these are probably the
most accurate because infants riding dorsally are
so conspicuous. One infant, extreme in this re-
spect, began riding on its mother’s back by the
fourth day. During the next ten days it was seen
riding 26 times, 10 of them (38%) on the
mother’s back. Even after they became proficient
at riding dorsally, most if not all infants rode
chiefly below for the first few months. Rarely I
saw a female carrying her infant and a yearling
at the same time, either with the infant below
and the yearling on her back, or with the yearling
below the infant and clinging to it.
The relationship between sex and rate of de-
velopment was obscured by the crudity of the
data, the relative permissiveness of the mothers
and the preponderance of females among the
early births (15-11 by April 1, though only
16-14 over-all). Females tended to ride on their
mothers’ backs sooner than males, but in most
activities neither sex was clearly ahead.
Social Relations of Infants
The speed of an infant’s socialization prob-
ably depends on the interplay of three factors:
(a) the infant’s own physical and mental char-
acteristics, (b) social facilitation, influenced by
the infant’s time of birth relative to its peers,
and (c) the relative permissiveness of its mother.
The effects of minor physical and mental differ-
ences between the infants could not be deter-
mined in the field, and no greatly accelerated
development or gross deficiences were seen. The
possible role of social facilitation was not clear
from this study, since all of the infants except
female ll’s had potential playmates from the
start, and social play typically began when the
infants were three to four weeks old. Female 1 l’s
infant, with no playmates available during its
first month, apparently did not begin social play
until the eighth week. This was partly due, how-
ever, to 1 l’s unusual persistance in keeping other
monkeys from her infant. In general, the moth-
ers’ temperament seemed most often to limit the
infants’ socialization. Almost every infant was at
first forcibly restrained by its mother from ap-
proaching, or being approached by, other mon-
keys.
Because of the limitations of field observations,
I could identify only the more obvious of the
infants’ vocal signals (Table 2) . Three indicated
generalized distress of varying intensity, whereas
“mewing” was apparently a more specific signal
which fuctioned as a “lost” call.
Table 2. Vocal Signals of Infants
Signal
Week when
first heard
Apparent causes
Mothers’ responses
Squeak
1
1. Inf. fell from mother’s back
2. Inf. unable to climb onto mother
1, 2. Picked up and held inf.
Gecker
1
1. Inf. unable to locate nipple
2. Inf. treated roughly by mother
3. Inf. left behind by mother
4. Inf. treated roughly by another
adult female
5. Inf. handled or carried by
sibling or other immature
1, 2. None
3. Returned and carried inf.
4, 5. Picked up and held inf.
Scream
1
1 . Inf. fell from mother’s back
2. Inf. fell from branch and hung
by hands
3. Mother chased another monkey
that was near inf.
4. Inf. carried by sibling
5. Siblings fighting near inf.
6. Inf. located (carried?) 100
yards from mother
1. Transferred inf. below
2-6. Ran to inf. and held it
Mewing
7
1. Inf. carried by sibling 30
minutes
2. Inf. left behind 30 ft. in
tree
3. Inf. left behind 20 ft. on
ground
1. Followed but made no attempt
to regain inf.
2, 3. Returned to inf. and
carried it
20
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With Their Mothers
For the first day or two after birth an infant
typically remained in constant close contact with
its mother’s body, clutching the skin and fur on
her chest and abdomen as she sat or stood, often
with one arm around the infant. Occasionally
she groomed it for short periods (Fig. 4), but
more often she groomed with other members of
the band. Females 1 1 and DR both groomed
other monkeys much less than they were
groomed. Soon the infants began to spend short
periods on the ground out of physical contact
with their mothers. Female ll’s infant was first
seen out of contact on day 2, when she sat aside
and watched it lie and crawl on the ground for
three minutes. She did this frequently from then
on, and as early as day 7 left her infant on the
ground as she chased another monkey several
yards. DR’s infant, less active and with a more
restrictive mother, was not seen out of contact
until day 12, though it tried to leave and was
restrained at least as early as day 6. Neither of
the infants was seen out of contact with its
mother for more than five minutes at any one
time during the first month. Table 3 summarizes
all of this activity for females 1 1 and DR and
their infants.
Gradually the infants spent more time out of
contact and went farther from their mothers
(Table 4). As the females allowed their infants
to wander more, they also became less protective
and permitted the infants greater social freedom.
Finally there came a time when the females es-
sentially no longer restricted their infants’ move-
ments or social interactions. This stage of rela-
tive independence was reached by some infants
as early as the fifth week, though most did not
attain it until the seventh or eighth week, and one
not until the eleventh week.
The mothers’ permissiveness in allowing their
infants to leave them in nonsocial situations was
apparently not correlated with rank. All six of
the primiparous females, however, were among
the most restrictive mothers in this respect.
All of the mothers were protective toward
their young, usually snatching them up when a
fight broke out nearby, or when an alarm call
was heard. The mothers also frequently picked
up and held their infants when the latter were
approached by another monkey. During rain
showers each mother sat hunched forward with
her infant huddled close in under her chest and
abdomen.
Females AS and KA, both primiparous, han-
dled their infants roughly at times. The rougher
was KA, who frequently pulled her baby away
as it nursed, held it upside down, thumped it on
the ground or dragged it around by its arm.
Table 3. Comparison of old Female 11 and
Primiparous Female DR in Percent, of Time
Spent with Their Infants and Other Monkeys
During the First Month after Birth
Female 1 1 and her infant Were observed for 36.4
hours, DR and her infant for 21 hours.
11 DR
% of time % of time
Mother in Contact with Infant
Mother held infant
58.6
90.4
Mother groomed infant
4.8
0.6
Mother groomed with others
Her other young
24.6
—
Adult females
5.3
7.3
Immatures
0.7
1.0
Adult males
2.5
0.0
Mother Not in Contact
with Infant
3.5
0.7
100.0%
100.0%
During the first month a mother would occa-
sionally turn her infant upside down and touch
her lips and/or nose to its perineum (Fig. 5).
Though this behavior might aid in olfactory rec-
ognition of the infants, it was done usually after
the females had been sitting for some time hold-
ing their infants, rather than as a greeting. This
behavior was not correlated with the age or
breeding history of the mothers, or the sex of
the infants. Hall & DeVore (1965) reported sim-
ilar behavior toward infant baboons, but by other
males and females which approached the infants
and their mothers. These authors interpreted this
behavior as a greeting, and Hall (1962) also de-
scribed perineal mouthing as a form of greeting
between adult baboons.
None of the four females whose young were
delivered by cesarean section accepted them
afterwards in the highly disturbed laboratory
situation. After they were returned to the band
without their infants, however, three of these
females were seen to hold and cuddle other in-
fants.
With Immature Siblings
The schedule of the infants’ interactions with
Table 4. Distances Infants Walked from
Their Mothers at Different Ages
Distance
in feet
Day when first
seen (range)
Weeks in which
most infants attained
each distance
1
4-16
1-2
3
6-21
2-3
5
12-34
3-4
10
12-53
4-6
30
34-66
7-9
1966]
Kauf matin: Behavior of Infant Rhesus Monkeys
21
monkeys other than their mothers is summarized
in Table 5.
Some siblings, especially females, were very
solicitous. Whenever the infant left its mother
they quickly approached and sat by it, and often
touched, held, or even carried it. Siblings occa-
sionally picked up infants that were left behind
and carried them to their mothers. When another
monkey approached the infant a sibling might
chase the intruder or hold the infant, and siblings
sometimes rushed to take infants that were held
by alien adult females. In addition, some siblings,
mostly females, played frequently with the in-
fants, whereas others seldom played with or pro-
tected them.
With Other lmmatures
Immatures of other mothers, especially fe-
males, also showed great interest in infants.
These immatures usually approached mother
and infant, groomed the mother, and while doing
so briefly touched the infant. On four occasions
I saw an immature female groom an infant for
a few seconds. These immatures rarely had an
opportunity to hold or carry infants because of
the close watch kept by the infants’ mothers and
siblings.
Apparently immatures learn to respect the
protection infants receive from their immediate
families. Infants less than seven weeks old ap-
proached immatures 19 times, and on 14 occa-
sions the immatures retreated. Five times the in-
fant was ignored. The rank of the infant’s mother
had no apparent effect on the reactions of the
immatures.
With Other Infants
At first the infants ignored other infants even
when they were in physical contact, as when
their mothers groomed each other. Within a
week the young began to approach and reach for
other infants, and in the third week they began
to play with them. At first the play consisted of
climbing and crawling near each other, with little
or no contact. Then they began to touch each
other, jump and grab at each other, pull hair,
Table 5. Social Contacts of Infants with Monkeys other than Their Mothers
Type of contact
Day when
first seen
Weeks when typically
seen for first time
With siblings
Touched by
1
Groomed by
2
1
Held or carried by
7
Rarely seen
Reached for, approached,
Rarely seen
touched
5
Played with
27
2
With other immatures
5
Touched by
4
Groomed by
8
1
Held or carried by
3
Rarely seen
Reached for, approached,
Rarely seen
touched
6
2
Played with
34
7
With other infants
Touched by
4
1
Reached for, approached,
touched
4
1
Played with (little or
no contact)
15
3-4
Played with (frequent
contact)
19
6-7
With mature females
Touched by
3
1
Groomed by
9
3
Held by
22
Rarely seen
Carried by
18
Rarely seen
Reached for, approached,
touched
4
2
With mature males
Approached
23
8
Touched, climbed on
39
8
Touched by
56
8
22
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wrestle, chase and give inhibited bites (Fig. 6).
Contact play was usually fully developed in the
sixth or seventh week.
A careful record of each infant’s playmates
failed to show a general tendency for close rela-
tives to play together a disproportionate amount
of the time. The only exceptions were the infants
of the two highest-ranking females in the band,
which are thought to be mother and daughter or
sisters. Though play between close relatives
might be more important later, during the first
three months the choice of playmates was ap-
parently influenced more by which of the avail-
able infants were most active. Some infants were
conspicuously more active in play than others,
and the most active players were born at various
times throughout the birth season. All infants
played with other infants much more than they
played with their siblings.
With Mature Females
Other females, some of them with infants of
their own, frequently approached mothers with
infants and either sat a few feet away (Fig. 1)
or groomed the mother. Usually the infant was
only watched, but occasionally a female would
touch or even groom it briefly. Newly mature
females, especially, showed an active interest in
the infants, and the most persistent of these fe-
males was a four-year-old that did not give birth.
Even though mature females usually ap-
proached and picked up lone infants not their
own, these females sometimes backed off when
approached by an infant, just as did the imma-
tures. In 33 observed incidents the female ac-
cepted the advance of an infant 18 times, re-
treated 7 times, hit or pushed it away 5 times, and
ignored it 3 times. All of the retreats were from
infants whose mothers ranked in the top four,
and all five of the hostile reactions occurred
when the infants were in their second month. In
addition, two females were seen lip-smacking at
infants near their mothers, and another female
presented her perineum to an infant as it ap-
proached, then touched it. Both lip-smacking and
presenting are appeasing or submissive acts.
After the seventh week, when the infants be-
came relatively independent of their mothers,
other females sometimes followed, held and
groomed the infants, and less often carried them.
If a female’s own infant was present, she held
both together. In all observations, the “adopted”
infant refused to cling and broke away, or was
snatched from the female by one of its siblings.
Several times I saw a female pick up another in-
fant when her own was nearby, then pull it from
her quickly and forcefully when it did not cling,
or when her own infant returned. Twice mature
females (seven and nine years old) showed ap-
parent concern and tried to retrieve infants from
trees where they were climbing, even though the
infants’ own mothers ignored them.
With Mature Males
Mature males were never seen to approach in-
fants. As early as the third day, however, mothers
with infants groomed males. Though sometimes
in contact with the males on such occasions, the
infants were always ignored.
After several weeks infants occasionally ap-
proached males on their own, touched them and
even climbed on them. Each male’s responses to
such approaches varied from time to time, but
some males were more receptive than others to
infants. The rank of the males apparently did not
affect their responses. In the 25 incidents ob-
served, mature males 7 times ignored infants that
approached them, 6 times held them gently in
their arms, 3 times retreated from them and 9
times threatened, hit or grabbed at them.
The infants seemed to learn slowly the mean-
ing of agressive signals. Males threatened infants
with direct, open-mouthed stares and head bob-
bing, and occasionally a male hit an infant or
grabbed it and briefly pinned it to the ground.
The infants completely ignored this hostile be-
havior except on one occasion. When a 58-day-
old infant approached the highest ranking male,
he hit it, and when that had no effect he hit it
harder. The infant crouched and gave a slight
grin, both typical submissive acts used by adults.
Social Relations of Mothers
With Their Own Immatures
Mothers were very tolerant toward their young
of the previous three years. Some infants from
the previous year still nursed occasionally until
the new infants were born, but otherwise the im-
matures’ relations with their mothers were little
changed. Some immatures, because of their in-
terest in the infant, probably spent even more
time with their mothers after the new young ar-
rived than they had before. From the first day,
mothers groomed their one- to three-year-olds
and let them huddle against the infants (Fig. 7) .
The immatures were also allowed to touch and
even groom the infants. When an infant began
to crawl, its mother sometimes restrained it from
approaching its siblings and also occasionally hit
the immatures when they touched the infant.
Several times a one- or two-year-old, sitting be-
side its mother and infant sibling, suddenly
backed or jumped away grinning and screeching
for no apparent reason, or when the mother sim-
ply shifted her position.
It is enlightening to compare the mothers’
relative protectiveness from month to month and
1966]
Kauf matin : Behavior of Infant Rhesus Monkeys
23
Table 6. Relative Protectiveness of Mothers toward Infants at Different Ages and in the
Presence of Different Associates
The indices show the percent of potential physical contacts between infants and other monkeys which
were prevented by the infants’ mothers. N = the number of incidents observed.
Infants’ associates
1st month
2nd month
3rd month
N
Index (% )
N
Index (% )
N
Index ( % )
Other infants
41
22.0
284
3.9
229
1.7
Immature siblings
95
27.4
42
11.9
4
0.0
Other immatures
75
70.7
35
34.3
27
7.4
in respect to different categories of associates.
This trait can be shown by the per cent, of poten-
tial physical contacts (between infants and the
members of a given category) which were pre-
vented by the mothers (Table 6). The mothers
prevented such contacts by restraining their in-
fants from approaching, or by chasing off, the
other monkeys. For example, during the first
month the mothers prevented 27.4% of the po-
tential physical contacts between infants and
their siblings, and allowed 72.6% of the at-
tempted contacts to occur.
During the second month mothers rarely hit
their immatures when they approached the in-
fants, though female 1 1 continued to do so occa-
sionally as late as day 53. Siblings were occasion-
ally allowed to carry infants in the second month,
and female 1 1 was especially tolerant in this re-
spect. On day 46, her three-year-old daughter
carried the infant several hundred yards during
a half hour period. Female 1 1 stayed within 20
feet of the pair and twice sat touching them, but
made no attempt to regain the infant. Three
times 1 1 chased three- or four-year-old females
that approached her two young. All of the other
instances of siblings carrying infants were for
short distances, usually when the mother walked
away and left her infant behind.
In the third month the infants associated
chiefly with their peers, and only four meetings,
all unrestricted, were seen between infants and
their immature siblings.
Besides the aforementioned indices, protec-
tiveness is also indicated by the ages at which in-
fants achieve relative social independence from
their mothers. By neither criterion did primi-
parous mothers differ appreciably from multi-
parous ones. There were also no marked differ-
ences between high- and low-ranking females in
the age at which their infants achieved independ-
ence, and the protective indices revealed no
consistent differences in the protectiveness of
mothers of different rank in the presence of their
own immatures or other infants. There was,
however, an apparent tendency for higher rank-
ing females to be more protective in the presence
of other immatures (Table 7) . These figures are
suggestive, but too much importance should not
be attached to them because of the small sizes of
most of the samples. It is to be expected that
manifestations of rank would be weak or absent
in most of the behavior observed during this
study. It is known that a mother’s rank tends to
be passed on to her offspring, but this is probably
accomplished through her intervention during
disputes over such items as food and resting
places, and by the passive respect shown her and
her young by lower-ranking adults. During the
first three months the infants are nursing, their
behavior is chiefly exploratory and nonagonistic,
and other monkeys either ignore them or are
friendly. There is some evidence that the young
do not respect rank themselves until they are
several years old. For example, the immatures’
behavior toward the infants was evidently not
affected by the mothers’ rank, but the behavior
of adult females was.
Table 7. Relative Protectiveness of Mothers of Different Rank in the Presence of the Immatures
of Other Females
The indices show the percent of potential physical contacts between infants and these monkeys which
were prevented by the infants’ mothers. N = the number of incidents observed.
Rank of mother
1st month
2nd month
3rd month
N
Index (%)
N
Index (%)
N
Index (% )
High
48
85.4
14
57.1
12
16.7
Low
21
52.4
16
25.0
7
0.0
Medium
6
16.7
5
0.0
8
0.0
24
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With Other Immatures
Immatures other than siblings were allowed
to touch and groom infants as early as the third
day. These immatures also groomed the mothers
and were groomed by them as early as the fourth
day. However, the mothers were much more
protective in the presence of other immatures
than in the presence of their own immatures.
Some mothers were not seen to chase other im-
matures from their infants after the third week,
but others did so into the third month. Old fe-
male 1 1, though more permissive in allowing her
infant out of contact, was much more protective
than primiparous DR in the presence of other
monkeys during the first month. Thus, 1 1 chased
immatures seven times as often as she permitted
contact, while DR permitted contact as often as
she prevented it. The former continued to restrict
contacts as late as day 5 1 , while DR was not seen
doing so after day 27.
During the second month immatures were al-
lowed to touch and groom the infants more than
before. They began playing with some of the in-
fants as early as the fifth week, but with most of
them not until the sixth to ninth week. Although
one primiparous female chased immatures from
her infant as late as day 66, all mothers allowed
their infants to play with immatures in the third
month.
With Other Infants
During the first month mothers usually let
other infants approach, touch and even play with
their own infants. The first contacts were per-
mitted during the first week, and play was per-
mitted commonly as early as the third to fourth
week. Most mothers stopped restricting infant-
infant contacts entirely during the fifth to sev-
enth week, but a few still restricted contacts
between infants as late as the twelfth week.
As mentioned above, some mothers showed
interest in other females’ infants. During 21
hours of observation in the first month after her
infant was born, DR approached the infants of
other females 14 times, whereas in 36 hours of
observation, 1 1 approached none.
With Mature Females
The effect of parturition on relations between
mature females is complicated by the year ’round
tendency for these females to sit near and groom
each other. There is certainly an increase in these
activities when young are born, but we have no
quantitative measure of it. Mothers let other fe-
males sit within a few feet of them the day the
young were born, and also exchanged grooming
with these females beginning in the first week.
Other females likewise handled and groomed the
infants during the first week. DR permitted such
handling by another female as early as the fifth
day, while 1 1 was not seen to do so until day 16.
During the first month mothers chased other fe-
males, or restrained infants from them, 1/4 as
often as they permitted such females to sit near
them, groom with the mother, or handle the in-
fant. Because these figures include sitting near
and grooming the mother, they are not strictly
comparable to the protective indices for imma-
tures and other infants. During the second month
mothers chased other females or restrained in-
fants from them only 1 /7 as often as they toler-
ated such females. Some mothers were not seen
to interfere with infant-female contacts after the
third week, while others did so until at least the
end of the seventh week. During the third month
mature females were seen holding or grooming
infants not their own on eight occasions, and no
restriction of such contacts was observed.
The females’ rank had no effect on which ones
were permitted to sit near a mother and infant.
In 80% of the grooming sessions between
mothers and other mature females, however, the
lower ranking female was the groomer. This per-
centage does not include the frequent grooming
between mothers and daughters. Of the other
females allowed to hold or carry infants ( exclud-
ing close relatives), three-fourths were of lower
rank than the mothers. Mothers of new infants
were apparently groomed more in the first month
after birth than in the succeeding months.
With Mature Males
On the day of birth, females carrying newborn
young fed in the usual manner among crowds of
mature males and females. Females with infants
groomed adult males as early as the third day,
and the mothers tolerated contact between the
males and infants at such times as long as the
males ignored the infants. The first potential
infant-male contact away from the mother was
observed on day 23, when an infant approached
male 56. As 56 started to leave, the the mother
rushed over, grinning, grabbed her infant and
ran away. The next such incident was observed
on day 39, when 1 l’s infant approached and
touched male 14. He ignored the infant and 1 1
did not interfere. All of the other contacts ob-
served occurred during the seventh week or later
when infants approached males. The infants
were relatively independent by this time and only
once did a mother interfere. This incident in-
volved female I l’s infant on the 58th day, and
suggests how the offspring of a high-ranking fe-
male may achieve high rank under its mother’s
protection, as suggested by Koford (1963). As 1 1
sat watching three feet away, the infant ap-
proached male 08 and climbed all over him. At
first he ignored it, but after a few seconds 08
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Kaufmann: Behavior of Infant Rhesus Monkeys
25
jumped up, ran a few steps, stared, and bobbed
his head at the infant. As it approached again, 08
continued to stare and bob his head and when the
infant reached him he hit it. Immediately 1 1 at-
tacked 08 and chased him 20 feet. The infant
quickly approached 08 again and touched him.
08 jumped back at the touch, then ran off as 1 1
ran toward him. Eight days later as he was
groomed by 11, 08 held 1 l’s infant in his arms
and let it climb on him.
Comparison with Other Studies
Because the emphasis in this study was on the
social relations of infants and their mothers, little
of the information collected in laboratory studies
is directly comparable. With a few exceptions,
the individual behavior of the laboratory mon-
keys, especially those studied by Hines (1942)
and by Tinklepaugh & Hartman (1932), devel-
oped at approximately the same rate as the be-
havior of those which I observed in the field.
Sitting up, hopping, climbing, handling objects
and playing all developed at about the same age
in the laboratory and in the field. The two in-
fants studied by Foley ( 1934) and by Lashley &
Watson (1913) did not begin standing or walk-
ing until the 11th and 13th day, respectively,
while the other laboratory infants and the infants
in the field all did so during the first week. Un-
supported bipedal standing, observed during the
fourth week in the field, was reported in the lab-
oratory only by Hines, who first recorded it in the
sixth week. The infants studied by Hines began
vertical jumping in the fourth week, about the
same time as did those in the field. But jumping
was not observed by Lashley & Watson until the
seventh week, and not by Foley until the four-
teenth week. It was evident in the laboratory
studies, just as it was in the field, that the close
relationship between mothers and their infants
delayed the performance of some actions of
which the infants were physically capable. For
example, the infants observed by Tinklepaugh &
Hartman were able to walk as early as the first
day in their solitary testing periods, but did not
walk away from their mothers until the eighth
to tenth day.
The individual behavior reported by Hinde,
Rowell, & Spencer-Booth (1964) for infants in
social groups in outdoor runs was very similar
to that seen on Cayo Santiago. Such activities as
walking, climbing, and mouthing and handling
foreign objects all developed at about the same
ages in both studies. There were two conspicuous
differences, however. Bipedal locomotion for a
distance of several feet occurred only occasion-
ally in Hinde’s colony, from the seventh week
on. On Cayo Santiago this behavior appeared in
the second week. Furthermore, none of Hinde’s
monkeys rode on their mothers’ backs until the
17th day, and most of them began in the third
or fourth week. Hinde, Rowell & Spencer-Booth
observed that the mothers frequently tried to pull
the infants to a ventral position, and they con-
cluded that rhesus mothers do not like carrying
their babies on their backs. On Cayo Santiago
this behavior appeared as early as the fourth day,
was very common with some individuals, and
was frequently encouraged by the mothers.
Though this particular study covered only the
first three months after birth, other observations
show that dorsal riding is common among older
immatures in the Cayo Santiago colony.
A few comparisons can be made of the sociali-
zation of infants in the laboratory and on Cayo
Santiago. Hansen’s (1962) study of mother-in-
fant interactions revealed decreasing ventral con-
tacts, cuddling, nursing and grooming during the
first three months. He called this period the stage
of “maternal attachment and protection.” The
mothers’ tendency to restrain and retrieve their
infants declined sharply and then leveled off at
about 60 days. Rosenblum (1961) recorded an
initial increase in social play among infants, with
a plateau reached at the end of the second month.
Thus the age at which the infants reached a stage
of relative independence from their mothers
(second to third month) was roughly the same
in these restricted experimental set-ups as in the
field.
Hansen’s mothers could interact only with
their own and other infants, and he recorded
much positive and negative behavior toward the
other infants by the mothers. This sort of be-
havior was much less common on Cayo Santiago,
where the mothers interacted more with older
monkeys. Hansen concluded from his study that
active rejection by the mother was more impor-
tant than previous field studies had indicated in
contributing to the infants’ independence. He
pointed out, however, that this rejection may
have been accentuated by the laboratory situa-
tion, and I am inclined to agree with this. On
Cayo Santiago rejection of infants seemed in-
significant compared to the infants’ interest in
other monkeys, especially other infants. From
preliminary studies, Harlow, Harlow & Hansen
(1963) reported no significant differences in the
maternal responses of primiparous and multi-
parous mothers. This tentative conclusion agrees
with my observations on Cayo Santiago.
The social behavior of the infants observed by
Hinde, Rowell & Spencer-Booth was also similar
to that of the Cayo Santiago infants. The qual-
itative descriptions by Hinde, Rowell & Spencer-
Booth of the positions of infants on mothers, of
nursing, of carrying, and of play apply equally to
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the Cayo Santiago monkeys. Even the frequency
of mother-infant grooming (less than 5% of
total time) was similar in the two studies. The
infants in their colony first broke contact with
their mothers and first walked away from them
at about the same ages (1-2 weeks) as the in-
fants on Cayo Santiago. As in the Cayo Santiago
colony, the apparent development of locomotor
patterns by the infants was affected by the re-
strictions imposed by their mothers and by the
attractiveness of other monkeys. Social play be-
gan at about the same age in both colonies, but
in Hinde’s colony it was restricted by the mothers
for the first 8-10 weeks, whereas on Cayo Santi-
ago such restriction stopped about two weeks
earlier. Grooming of infants by other adult fe-
males was common in both colonies, but in
neither colony did adult males groom infants
during the first three months. Hinde, Rowell &
Spencer-Booth saw tentative grooming of moth-
ers by infants very rarely, and I never observed it.
The three generalized distress calls which I
heard infants use were used in similar contexts
by Hinde’s infants, but apparently the mewing
“lost call” was not given in his colony— probably
because the runs were too small for the infants
to get “lost.” The “fear grin” was apparently not
used by infants less than ten weeks old in Hinde’s
colony, whereas a slight but clearly recognizable
grin was given in the appropriate context by a
58-day-old infant on Cayo Santiago.
Rowell, Hinde & Spencer-Booth (1964) also
reported on the relations between infants and
“aunts”— other females in the same band. As on
Cayo Santiago, these females tended to sit near
the mother and groom her to get near the infant.
However, grooming of the infants by “aunts”
did not begin in their colony until the fourth
week, while on Cayo Santiago it began in the
first week. Other females carried and cuddled
infants in the first three months in both studies,
and in Hinde’s colony “aunts” began playing
with the infants in the sixth week. Adult females
were not seen playing with infants on Cayo San-
tiago, but Rowell, Hinde & Spencer-Booth in-
cluded among the “aunts” females two and three
years old. I included these young females among
the “immatures,” which began playing with the
infants at about the same age. Relative social
independence from their mothers was achieved
in the second or third month by infants in both
colonies. Finally, Rowell, Hinde & Spencer-
Booth reported no consistent differences in the
behavior of “aunts” which ranked higher and
lower than the mothers, although the mothers
permitted contact between infants and subordi-
nate “aunts” more often than between infants
and “aunts” who outranked the mothers. This
agrees with my observations on Cayo Santiago.
The only information available on the early
development of rhesus infants in their native
India is that provided by Southwick, Beg &
Siddiqi (1965) on the behavior of one infant
and its mother during the first week after birth.
Their account generally agrees with the data
from Cayo Santiago.
To sum up, the individual and social develop-
ment of rhesus infants in captivity and in the
field is very similar for those patterns which are
appropriate to the captive situation. Certain so-
cial patterns are especially apt to be lacking in
the laboratory where social interaction is se-
verely limited. Not surprisingly, the few differ-
ences in rate of development that are apparent
in the two situations indicate a slightly retarded
development (or use) in captivity, especially of
social acts. Such differences are probably due to
a combination of individual differences (accen-
tuated by the small size of most laboratory sam-
ples), and the social restrictions of the captive
colonies. The Cayo Santiago colony is itself a
“captive” one, but the social environment for
very young infants is probably essentially like
that in wild bands in India. A more detailed
study of infant development on Cayo Santiago
would be both feasible and highly desirable.
Summary
The behavior of infant rhesus monkeys and
their mothers during the first three months after
birth was studied in the free-ranging colony on
Cayo Santiago. Newborn infants clung to their
mothers’ venters, but began to sit and crawl on
the ground as early as the second day. Some tra-
veled ten feet in the third week. Climbing on
vines and bushes became common in the second
to third week. At first an infant would cling be-
low as its mother walked, but as early as the first
week a few began riding on her back part of the
time.
The infants’ movements and social interac-
tions were restricted by their mothers for about
seven weeks. Siblings were frequently allowed in
contact with the infants from the first day, but
contacts with other immatures were severely lim-
ited during the first month. Toward other infants
the mothers were much more tolerant. Play with
immatures and other infants was common by the
seventh week. Other mature females tended to
gather around and groom mothers with infants.
These females were generally allowed to touch
the infants during the first week. Although adult
males usually ignored the infants, they were
sometimes hostile when the infants approached.
Some mothers who were relatively permissive
in allowing their infant to leave them in nonso-
cial situations were relatively protective in the
1966]
Kauf matin: Behavior of Infant Rhesus Monkeys
27
presence of other monkeys. Primiparous mothers
tended to be restrictive in the former respect, but
permissiveness was not correlated with social
rank. Protectiveness in social situations was not
correlated with past breeding history, and not
obviously with rank. High-ranking mothers, how-
ever, tended to be more protective in the pres-
ence of the immature offspring of other females.
Comparison of the Cayo Santiago infants with
those in laboratories and outdoor runs shows
close agreement in the rates of development of
most kinds of behavior. The exceptions were
chiefly in social behavior, and were probably due
to a combination of individual differences and
the more complex social environment on Cayo
Santiago.
Literature Cited
Altmann, S. A.
1962. A field study of the sociobiology of rhesus
monkeys, Macaca mulatto. Ann. N. Y.
Acad. Sci., 102: 338-445.
Foley, J. P., Jr.
1934. First year development of a rhesus mon-
key (Macaca mulatto) reared in isolation.
J. Genet. Psychol., 45: 39-105.
Hall, K. R. L.
1962. The sexual, agonistic and derived social
behavior patterns of the wild chacma
baboon, Papio ursinus. Proc. Zool. Soc.
Lond., 139: 283-327.
Hall, K. R. L., & I. DeVore
1965. Baboon social behavior. In I. DeVore, Ed.,
Primate behavior: field studies of mon-
keys and apes. New York: Holt, Rinehart
and Winston, pp. 53-110.
Hansen, E. W.
1962. The development of maternal and infant
behavior in the rhesus monkey. Ph. D. dis-
sertation, Univ. of Wisconsin.
Harlow, H. F„ M. K. Harlow & E. W. Hansen
1963. The maternal affectional system of rhesus
monkeys. In H. L. Rheingold, Ed., Ma-
ternal behavior in mammals. New York:
Wiley, pp. 254-281.
Hinde, R. A., T. E. Rowell & Y. Spencer-Booth
1964. Behavior of socially living rhesus monkeys
in their first six months. Proc. Zool. Soc.
Lond., 143: 609-649.
Hines, M.
1942. The development and repression of re-
flexes, postures and progression in the
young macaque. Contr. Embryol. Car-
negie Inst. Wash., 30: 153-209.
Koford, C. B.
1963. Rank of mothers and sons in bands of
rhesus monkeys. Science, 141: 356-357.
Lashley, K. S., & J. B. Watson
1913. Notes on the development of a young
monkey. J. Animal Behav., 3: 114-139.
Mason, W. A.
1965. The social development of monkeys and
apes. In I. DeVore, Ed., Primate behavior:
field studies of monkeys and apes. New
York: Holt, Rinehart and Winston, pp.
514-543.
Mowbray, J. B. & T. E. Cadell
1962. Early behavior patterns in rhesus mon-
keys. J. Comp. Physiol. Psychol., 55: 350-
357.
Rosenblum, L. A.
1961. The development of social behavior in the
rhesus monkey. Ph. D. dissertation, Univ.
of Wisconsin.
Rowell, T. E„ R. A. Hinde & Y. Spencer-Booth
1964. “Aunt”-infant interactions in captive rhe-
sus monkeys. Animal Behav., 12: 219-226.
Southwick, C. H., M. A. Beg & M. R. Siddiqi
1965. Rhesus monkeys in north India. In I. De-
Vore, Ed., Primate behavior: field studies
of monkeys and apes. New York: Holt,
Rinehart and Winston, pp. 111-159.
Tinklepaugh, O. L„ & C. G. Hartman
1932. Behavior and maternal care of the new-
born monkey (Macaca mulatto-' M. rhe-
sus”). J- Genet. Psychol., 40: 257-286.
28
Zoologica: New York Zoological Society
[51: 2
EXPLANATION OF THE PLATES
Plate I
Fig. 1. Two pregnant females watch as the band’s
highest-ranking female nurses her month-
old infant.
Fig. 2. Female DR’s 2-mo. -old infant clings below
as she walks. A 4-yr.-old female submis-
sively presents her perineum.
Plate II
Fig. 3 A 3-mo. -old infant rides on its mother’s
back as she feeds near the band’s highest-
ranking male.
Fig.
4.
A mother grooms her 2-wk.-old infant.
Plate III
Fig.
5.
A mother holds her infant upside down as
she mouths its perineum.
Plate IV
Fig.
6.
A mother sits unconcernedly as her 7-wk.-
old young plays with another infant.
Fig.
7.
A yearling sits in contact with its mother
and infant sibling.
KAUFMANN
PLATE I
FIG. 1
FIG. 2
BEHAVIOR OF INFANT RHESUS MONKEYS AND THEIR MOTHERS
IN A FREE-RANGING BAND
KAUFMANN
PLATE II
FIG. 3
FIG. 4
BEHAVIOR OF INFANT RHESUS MONKEYS AND THEIR MOTHERS
IN A FREE-RANGING BAND
KAUFMANN
PLATE III
FIG. 5
BEHAVIOR OF INFANT RHESUS MONKEYS AND THEIR MOTHERS
IN A FREE-RANGING BAND
BEHAVIOR OF INFANT RHESUS MONKEYS AND THEIR MOTHERS
IN A FREE-RANGING BAND
KAUFMANN
PLATE IV
3
Head Muscles of Boa constrictor
Frances W. Gibson
University of Arkansas, Fayetteville, Ark.
(Text-figures 1 & 2)
Introduction
THIS paper presents a complete description
of the head muscles of Boa constrictor, in-
cluding muscle form, origin, insertion, lo-
cation, variations and to a lesser extent function
and innervation. This will serve as a basis for
comparison of the head muscles of the other
American boids and, eventually, all Boidae. Boa
constrictor was chosen for basic description be-
cause of its generalized form, large size and
availability.
Morphological studies on snakes have usually
taken one of two approaches; either (1) an organ
has been described in a number of different, and
often unrelated, species (i.e., lungs, Brongersma,
1951; hemipenes, Dowling & Savage, 1960; tri-
geminal musculature, Lakjer, 1926) or (2) some
aspect of the anatomy has been described thor-
oughly in a single species (i.e., jaw muscles,
Cowan & Hick, 1951; Albright & Nelson, 1959;
circulation, Jacquart, 1855; Ray, 1934). These
and many similar, essential works, do not com-
plete our understanding of snake morphology.
No particular internal structure has been studied
throughout a taxonomic group, so it is not known
what amount of variation is normal and what is
of specific, generic or familial importance. Often
it is not known that a structure on which a taxo-
nomic group is partially based actually exists in
all members of that group. This lack of knowl-
edge of snake morphology has hampered taxon-
omists trying to erect a classification of the
Serpentes reflecting true relationships (Dowling,
1959).
Among the previous writers on head muscles
of pythonids and boids, D’Alton ( 1834) was the
first. His account of the muscles of the head,
trunk, pelvic and tail regions of Python bivittatus
forms an excellent beginning even though he
uses letters or descriptive phrases instead of
names for the muscles. Owen (1866) and Bronn
(1890) gave generalized discussions of snake
head muscles and innervations using illustrations
of Python. The more prominent head muscles of
Python regius were described rather briefly by
Phisalix, (1922). Lakjer (1926) included Boa
constrictor in his extensive comparison of the
adductor mandibulae and constrictores dorsales,
their innervations and functions in a number of
reptiles and birds. In 1935, Radovanovic com-
pared the form of a few head muscles in a group
of snakes including three boids and pythonids.
The usefulness of the description of the head
muscles of Eunectes murinus by Anthony & Serra
(1950) is limited by its brevity. Haas (1955)
suggested a new taxonomic position for Loxo-
cemus based on musculature. Frazzetta (1959)
began a series of papers on boid skulls; therefore,
descriptions of skulls will be omitted here.
Materials and Methods
Five specimens of Boa constrictor, four from
Chicago Natural History Museum (CNHM
34489, 31700, 31702, 31703) and one from the
American Museum (AM 79032) , were dissected
with the aid of a Bausch & Lomb stereozoom
dissecting microscope. A Boa constrictor skull,
CNHM 22363, was used in determining exact
locations of origins and insertions. Albright &
Nelson ( 1959) was used in identifying the mus-
cles but the terminology was found to be cum-
bersome and was abandoned in favor of Lu-
bosch’s terms (1938). The identification of
nerves was accomplished with the aid of Owen
( 1866) , Bronn ( 1890) , Lakjer ( 1926) and Oel-
rich (1956). Hoffstetter (1939) was used for
osteological terms when possible. A live speci-
men of Boa constrictor, caught in Trinidad, West
Indies, in the summer of 1960, was observed
while feeding, and muscle functions were de-
duced from these observations.
29
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Trigeminal Innervation
Externally, the opening in the cranium for the
trigeminal nerve is divided by a septum of bone
into an anterior and posterior trigeminal fora-
men. The anterior foramen carries the ramifica-
tions of the second (maxillary) branch of the
trigeminal nerve, Vo, while the posterior fora-
men carries the third (mandibular) branch, V3,
and several of its ramifications. The most promi-
nent ramus issuing from the posterior foramen
is the mandibular branch, itself, passing caudo-
ventrad over the lateral face of the adductor
posterior into the mandibular fossa. From the
dorsal surface of the mandibular ramus, close
to the foramen, a sizable ramus, the adductor
profundus and posterior nerve, is given off.
Lakjer ( 1 926, P 1 , XXI, figs. 1 80 & 1 82 ) labeled
this nerve “cutaneous,” which is undoubtedly a
mistake for all branches of the nerve ended in
the muscle. The mandibular branch also has a
ventral ramus, the pterygoideus nerve, lying on
the medial surface of the adductor posterior.
Lakjer indicates that there are rami of this nerve
to the pseudotemporalis and the adductor pos-
terior but these were not seen. Emerging from
the foramen are four smaller rami of the mandi-
bular branch lying rostro-dorsal to the mandi-
bular branch. The four rami may be united
briefly in varying combinations. The anterior
ramus is the adductor superficialis nerve and the
other three constitute the adductor medialis
nerve. No twig of the four rami passed to the
adductor profundus as is shown in Lakjer. Issu-
ing from the foramen ventral to the adductor
superficialis and medialis nerves is the pseudo-
temporalis nerve. It passes rostro-ventrad to the
pseudotemporalis and enters the lateral surface
of the muscle.
Before the mandibular branch of the trigemi-
nal nerve, V3, emerges from the skull, it pro-
duces two ramifications which constitute V4.
These are the retractor pterygoidei and retractor
vomeris nerve and the protractor pterygoidei and
levator pterygoidei nerve. There are three fora-
mina located, in general, ventro-medial and an-
terior to the foramina trigemini, by which these
ramifications leave the cranium. The retractor
pterygoidei and retractor vomeris nerve utilizes
the anterior one of the three and does not re-
branch until after its emergence. The protractor
pterygoidei and levator pterygoidei nerve divides
into branches a. and b. which exit through the
posterior foramen and the center foramen, re-
spectively. Branch a. supplies the protractor
pterygoidei while branch b. affords innervation
to both the protractor and levator of the ptery-
goid (Lakjer, 1926).
CONSTRICTORES DORSALES
la. Levator pterygoidei
lb. Protractor pterygoidei
lc. Retractor pterygoidei
ld. Retractor vomeris
The constrictores dorsales are the muscles of
the palatal region governing movements of the
visceral skeleton. A protractor quadrati is not
differentiated in Boa constrictor.
la. Levator pterygoidei.— ( Synonymy: Hebe-
muskel des inner Fliigelbeins, D’Alton, 1834;
pterygo-parietalis, Bronn, 1890; Radovanovic,
1935; post-orbito-pterygoideus, Anthony & Ser-
ra, 1950). (Text-fig. 1 ). The levator pterygoidei
is a fleshy, short muscle of the deep postorbital
region. The fibers run from the parietal to the
pterygoid in a ventro-caudal direction.
Location.— The levator pterygoidei is a deep
lateral muscle lying medial to the adductores
mandibulae externi and reaching anteriorly into
the orbital region, where its medial surface is in
contact with the retractor pterygoidei. The pro-
tractor pterygoidei lies immediately dorsal to the
levator in the insertional region.
Origin.— On the ventro-posterior edge of the
transverse process of the parietal and a small
portion of the ventro-rostral, or orbital, face of
the process.
Insertion.— On the dorsal face of the pterygoid
immediately posterior to the pterygo-ectoptery-
goid articulation and the lateral face of the crista
pterygoidea caudad to the point where the ridge
becomes the lateral edge of the pterygoid.
Innervation.— Branch b. of the protractor
pterygoidei and levator pterygoidei nerve leaves
the cranium through the middle foramen of the
V4 foramina. Branch b. innervates the levator
pterygoidei entering the muscle after sending
twigs to the protractor pterygoidei.
Function— The levator pterygoidei has a more
complex activity than the mere raising of the
pterygoid. The crista pterygoidea is laterally
concave and has an upswinging curve to its dor-
sal edge, which, when the pterygoid is protracted
and elevated, is pushed against the pterygoid
process of the basisphenoid. The pterygoid proc-
ess serves as a pivot and the ptergoid, due to the
shape of the crista pterygoidea, rotates on a
transverse axis at the point of contact. Thus, the
levator pterygoidei, in elevating and protracting
the posterior half of the pterygoid, causes the an-
terior area to be depressed, and in doing so, low-
ers the palatine process of the maxillary. The
ectopterygoid is likewise depressed, lowering
the posterior end of the maxillary. This action
is assisted by the pterygoideus. The maxillary
1966]
Gibson: Head Muscles of Boa Constrictor
31
LEVATOR PTERYGOIDEI
PSEUDOTEMPORALIS
DEPRESSOR MANDIBULAE
RETRACTOR QUADRAT!
PERVICO MAMDIBULARIS
VERTEBRAL HEAD
PTERYGOIDEUS
HYOTRACHEALIS
INTERMANDIBULARIS POSTERIOR VENTRAL1S
MEDIAL HEAD
NEUROCOSTOMANDIBULARIS'
Text-fig. 1. Deep muscles of Boa constrictor, lateral view. 1. Origin of adductor superficialis. 2. Origin
of adductor medialis. 3. Origin of adductor profundus. 4. Insertion of adductor superficialis. 5. Insertion of
adductor medialis. 6. Insertion of adductor profundus and posterior.
then pivots on its palatine process, raising the
anterior end.
lb. Protractor pterygoidei.— (Synonymy : In-
nerer, hinterer Fliigelmuskel, D’Alton, 1834;
presphenopterygoideus, Owen, 1866; pterygo-
sphenoidalis posterior, Bronn, 1890; Radovano-
vic, 1935; spheno-pterygoideus, Phisalix, 1922;
Anthony & Serra, 1950) . (Text-fig. 1 ) . The pro-
tractor pterygoidei is a large well-developed mus-
cle having its ventral surface in contact with the
mucosa anteriorly and with the pterygoid, pos-
teriorly. In Boa, although some of the fibers in-
sert on the quadrate, a protractor quadrati is not
differentiated. From the basisphenoid, the fibers
run caudo-laterad to the very end of the ptery-
goid, covering almost all of the dorsal surface of
the pterygoid from the pterygoid process of the
basisphenoid caudad. The protractor pterygoidei
is fleshy throughout. Although the crista ptery-
goidea tends to divide the muscle into two bun-
dles, two heads are not formed.
Location— The protractor pterygoidei is med-
ial to the adductores mandibulae externi. The
latero-anterior fibers are in contact with the
levator pterygoidei, while medially the fibers are
adjacent to body muscle which have their origins
on the basisphenoid and basioccipital. The an-
terior fibers are separated from the retractor
vomeris by a heavy sheet of fascia.
Origin.— On the basisphenoid along the mid-
ventral area and the median ridge. It also ex-
tends onto the medial and postero-medial faces
of the pterygoid process of the basisphenoid and
onto the basioccipital in the midventral region.
The level of the third pterygoid tooth socket
marks the anterior end of the origin.
Insertion— Beginning at the level of the foot-
plate (posterior to the insertion of the levator
pterygoidei) , on the dorsal surface of the ptery-
goid. A fasiculus of the protractor pterygoidei
inserts on the quadrate ventral to the process to
which the columella attaches.
Innervation.— The. protractor pterygoidei and
levator pterygoidei nerve of V4 divides into
branches a. and b. Branch a. finds its egress
through the posterior foramen of the V4 fora-
mina and innervates the protractor pterygoidei.
Branch b. utilizes the middle foramen and inner-
vates both the protractor and levator pterygoidei.
Function.— Protraction of the entire palato-
pterygoid complex, and, since the quadrate and
mandible are bound tightly by ligaments to the
posterior tip of the pterygoid, they also are pro-
tracted. Because of the location of the transverse
32
Zoologica: New York Zoological Society
[51: 3
process of the premaxillary, the maxillary cannot
move straight forward from a resting position.
The protractor pterygoidei pulls the pterygoid
mediad during protraction and this action is
reflected in the posterior tip of the maxillary
through the ectopterygoid. The anterior end of
the maxillary is thus abducted laterad as the bone
pivots at the palatine process enabling the maxil-
lary to be protracted.
The postero-ventral projections of the pre-
frontals are connected to the palatine and maxil-
lary by ligaments. These connections transmit
the movements of the palato-pterygoid complex
to the nasal complex and the protraction of the
former causes a dorsal rotation on a transverse
axis of the latter.
lc. Retractor pterygoidei.— ( Synonymy: In-
nerer, vorderer Fliigelmuskel, D’Alton 1834;
presphenopalatine, Owen, 1866; pterygo-sphen-
oidalis anterior, Bronn, 1890; Radovanovic,
1935; spheno-palatinus, Phisalix, 1922; Anthony
& Serra, 1950). Another muscle of the ventro-
lateral parietal region, the retractor pterygoidei,
is situated, for the most part, medial to the le-
vator pterygoidei and the course of the fibers is
rostro-ventrad and very slightly laterad. No
tendons are formed.
Location — In the region of its origin, the
retractor pterygoidei occupies the concave an-
tero-lateral face of the pterygoid process of the
basisphenoid and the levator pterygoidei lies
dorso-lateral to it. More anteriorly, the fascia of
the orbit covers the dorsal surface of the retrac-
tor pterygoidei. The pterygoid and mucosa are
found ventral to the muscle and the retractor
vomeris, ventro-medial, the two muscles being
separated by a sheet of heavy fascia. Caudally,
the pterygoid process separates the retractor
pterygoidei from the protractor.
Origin.— Considering the small size of the re-
tractor pterygoidei, the origin is rather broad,
occupying the area between the transverse proc-
ess of the parietal and the pterygoid process of
the basisphenoid, including the antero-lateral
face of the latter process, and the ventro-lateral
region of the parietal anterior to that process.
Insertion.— On the pterygoid, on its dorso-
medial ridge, between the levels of the vomerine
process of the palatine and the pterygoid process
of the basisphenoid.
Innervation.— The retractor vomeris and re-
tractor pterygoidei nerve leaves the skull through
the anterior foramen of the V4 group. The nerve
divides sending a branch to the retractor vomeris
and one to the retractor pterygoidei.
Function.— The protraction of the pterygoid
complex is accompanied by a slight depression
of the anterior end of the pterygoid and the
posterior end of the palatine plus some lateral
displacement of this part of the complex. The
retractor pterygoidei retracts the pterygoid com-
plex, elevates the anterior end of the pterygoid
and counteracts the lateral displacement.
Id. Retractor vomeris.— (Synonymy: Zuriick-
zieher des Vomer, D’Alton, 1834; prespheno-
vomerine, Owen, 1866; vomero-sphenoideus,
Bronn, 1 890; spheno-vomerinus, Phisalix, 1922;
spheno-vomeris, Anthony & Serra, 1950). The
retractor vomeris is a palatal muscle lying paral-
lel to the mid-ventral line of the cranium. This
muscle is comprised of a fleshy posterior and a
tendinous anterior portion. At the origin, the
muscle is compressed dorso-laterally and ventro-
medially so that it lies in a plane tilted about 45
degrees from the sagittal plane of the head. The
fibers run rostrad, converging somewhat from
the origin to the tendon.
Location.— At its origin, the retractor vomeris
is compressed between the retractor pterygoidei,
dorso-laterally, and the protractor pterygoidei,
ventro-medially. Anterior to the origin, the mu-
cosa covers the muscle ventrally and fascia en-
closing Meckel’s cartilage is dorsal to it.
Origin.— From the sharp anterior ridge of the
pterygoid process of the basisphenoid and a
small area of the wall of the process just lateral
to the ridge.
Insertion— The prominent tendon of the re-
tractor vomeris inserts on the posterior point of
the lamellar process of the vomer.
Innervation.— By a twig of the retractor vo-
meris and retractor pterygoidei nerve.
Function.—' The elevation of the nasal com-
plex, which includes the paired vomers, is op-
posed by the action of the retractor vomeris.
Adductores Mandibulae
2a. Adductor mandibulae externus superfici-
alis
2b. Adductor mandibulae externus medialis
2c. Adductor mandibulae externus profundus
and adductor mandibulae posterior
2d. Adductor mandibulae internus pterygoid-
eus
2e. Adductor mandibulae internus temporalis
(pseudotemporalis)
The adductores mandibulae, the largest group
of head muscles, form the contours of the head
in the parietal region, from the parietal crest to
the mandible and from the postorbital to the
quadrato-mandibular articulation. They are im-
portant in controlling the rotation of the mandi-
ble on a longitudinal axis, as well as the closing
1966]
Gibson: Head Muscles of Boa Constrictor
33
ADDUCTOR SUPERFICIALIS
\ ADDUCTOR MEDIALIS
\ \ ADDUCTOR PROFUNDUS
DEPRESSOR MANDIBULAE
\ CONSTRICTOR COLLI
CERVICOMANDIBULARIS vfrtfrrai HEAD
RETRACTOR QUADRAT I
’iNTERMANOIBULARIS POSTERIOR VENTRALIS
SUPERFICIAL HEAD
INTERMANDIBULARIS PORTION OF
NEUROCOSTOMANOIBULARIS
Text-fig. 2. Superficial muscles of Boa constrictor, lateral view.
of the lower jaw. The adductor superficialis initi-
ates the closing action, and, because of the posi-
tion of the insertion of the aponeurosis, also
rotates the teeth inward. The pterygoideus, by
contracting slightly in conjunction with the de-
pressor mandibulae, rotates the teeth outward
during the opening of the mouth.
The adductor profundus and adductor poste-
rior are separated in the area of the mandibular
branch of the trigeminal nerve only and are
treated together here.
The pterygoideus is not subdivided.
2a. Adductor mandibulae externus superfici-
alis.— (Synonymy : temporalis a, D'Alton, 1834;
masseter, Owen, 1866; Radovanovic, 1935; par-
ietali-quadrato-mandibularis a, Bronn, 1890;
temporalis anterior, Phisalix, 1922; Anthonv &
Serra, 1950) . (Text-fig. 2) .This muscle lies poste-
rior to the orbital region but anterior to the other
two adductor externus muscles. The fibers are
directed caudo-laterad from the origin and curve
caudo-ventrad around the side of the head, form-
ing a band. The fleshy part of the muscle lies in
a depression of the adductor medialis and is
superficial except where the muscle becomes
aponeurotic. There it is medial to the rictal plate
and zygomatic ligament. A sheet of fascia ex-
tends from the medial surface of the rictal plate
and at right angles to it, upward to the superficial
part of the adductor medialis, becoming continu-
ous with the fascia of the muscle. This sheet of
fascia separates the adductor superficialis from
the medialis.
Location.— A superficial muscle but its apo-
neurosis is covered by the zygomatic ligament
and the rictal plate. The muscle lies in a depres-
sion of the adductor medialis and only the
anterior end is in contact with the underlying
transverse process of the parietal.
Origin.— (Text-fig. 1). From the dorso-caudal
faces of the parietal, transverse process, and the
postorbital, just posterior to the fronto-parietal
suture.
Insertion — (Text-fig. 1). The extensive apo-
neurosis by which the adductor superficialis is
inserted also receives a portion of the adductor
medialis. The aponeurosis is attached to the
mandible, from the anterior edge of the coronoid
process, ventrad along the lateral face of the
angular passing just posterior to the supra-angu-
lar foramen, and caudad along the crista lateralis
to terminate anterior to the sigmoid fossa.
Innervation.— The adductor superficialis nerve,
which branches off the anterior ramus of the
adductor medialis nerve before emerging from
the posterior trigeminal foramen, enters the ad-
ductor superficialis on its medial surface.
Function— When the mandible is fully ab-
ducted, both ventrad and laterad, and rotated
laterad on its longitudinal axis, contraction of
the adductor superficialis rotates the teeth in-
ward and adducts the mandible dorsad.
2b. Adductor mandibulae externus medialis.—
(Synonymy: temporalis b, D’Alton, 1834; tem-
poralis, Owen, 1866; parietali-quadrato-mandi-
bularis b, Bronn, 1890; temporalis medialis,
34
Zoologica: New York Zoological Society
[51: 3
Radovanovic, 1935; Anthony & Serra, 1950).
(Text-fig. 2). This bulky muscle is the largest
of the three adductor externus muscles. The fi-
bers, converging ventrad, caudo-ventrad, and
rostro-ventrad, from a very wide origin, insert
both on the bone of the mandible and on an
aponeurosis. Part of the aponeurosis is continu-
ous with that of the adductor superficialis. There
is some indication of the development of two
fasciculi in the region of the insertion. Here the
aponeurosis is also separate, forming two layers
which soon fuse.
In the posterior portion of the adductor medi-
alis, there is fusion of several small caudo-medial
fasciculi with the adductor profundus. Some
specimens exhibit slight fusion between the ad-
ductor superficialis and medialis.
Location.— Dorsally, the adductor medialis lies
between the adductor superficialis and pro-
fundus and, in this area, it is superficial and
quite prominent. In the postorbital region, the
adductor superficialis crosses over the medialis.
Caudo-dorsally, the occipital slip of the depres-
sor mandibulae crosses a portion of the adductor
medialis. The large postero-ventral face of the
muscle adjoins the adductor profundus and pos-
terior. Medially, the muscle overlies the lateral
face of the pseudotemporalis, the crest of the
parietal, the supratemporal, supraoccipital, max-
illary branch of the trigeminal nerve, and the
levator pterygoideus.
Origin— (Text-fig. 1). Covering the entire face
of the parietal and supraoccipital crest. Most of
the fibers pass over the dorso-lateral face of the
supratemporal, forming only a loose attachment
with the periosteum. Near the quadrato-supra-
temporal articulation, some fibers originate from
the supratemporal, ventro-lateral, to dorso-me-
dial surfaces, and from a small portion of the
fascia of the depressor mandibulae. At the pos-
terior extremity of the origin, some of the fibers,
coming from the exoccipital and a tendon from
the ventro-medial face of the supratemporal,
pass dorso-rostrad over the supratemporal and
thence ventro-rostrad to the insertion.
Insertion— (Text-fig. 1). Either by fibers di-
rectly to the bone of the dorsal tip of the coro-
noid process or by tendon and fibers with the
fibrous portion confined to the caudo-lateral face
of the process. The greater part of the insertion
of the adductor medialis is aponeurotic. The
aponeurosis is actually a medial layer of the ad-
ductor superficialis aponeurosis and the two fuse
ventrally at the rostral end of the insertion which
runs from the coronoid process ventrad over the
lateral face of the supra-angular and on to the
crista lateralis.
Innervation.— The adductor medialis nerve is
comprised of three rami of V3 emerging from the
antero-dorsal part of the posterior trigeminal
foramen. The anterior ramus of the three gives
rise to the adductor superficialis nerve. The
nerves enter the medial surface of the muscle.
Function.— The fibers, straightened into a ven-
tro-lateral direction by the abduction and pro-
traction of the mandible, adduct the mandible
and rotate it mediad by their contraction.
Variations.— The fibers originating from the
exoccipital and the tendon from the ventro-me-
dial face of the supratemporal and the fascia of
the depressor mandibulae may be either a part
of the adductor medialis or a part of the ad-
ductor profundus.
Along the caudal border of the adductor medi-
alis, a shallow separation into two fasciculi with
a corresponding doubling of the aponeurosis is
sometimes discernible.
While the coalescence of the adductor medi-
alis with the superficialis is most often absent
and, when present, involves only a few fibers,
fibers common to both adductor medialis and
profundus are nearly always present and may
prevent a clear-cut division of the muscles for
half of their adjoining surfaces.
2c. Adductor mandibulae externus profundus
and adductor mandibulae posterior.— ! Synony-
my; temporalis c, D’Alton, 1834; posttemporalis,
Owen, 1866; parietali-quadrato-mandibularis c
and d, Bronn, 1890; temporalis posterior, Phisa-
lix, 1922; Radovanovic, 1935; Anthony & Serra,
1950) . (Text-fig. 2) . This is also a massive mus-
cle which lies, principally, caudo-ventral to the
adductor medialis, filling the angle formed by
the quadrate and the mandible. The direction of
the fibers varies from ventrad to rostro-ventrad.
The mandibular branch of the trigeminal nerve
provides a demarkation of the adductor pro-
fundus and posterior. The adductor posterior
does not form two heads.
A tendon originating from a lateral tuberosity
of the head of the quadrate, extends ventrad into
the muscle. Fibers of the muscle originate from
this structure on both its rostral and caudal faces.
The fibers from the rostral face pass rostro-vent-
rad while those from the caudal face are directed
caudo-ventrad.
Location— The adductor profundus and pos-
terior occupies the right angle formed by the
quadrate and the mandible. It is in contact dor-
sally and anteriorly with the medialis, dorso-
caudally and posteriorly with the depressor
mandibulae and the quadrate, ventrally with the
mandible and the pterygoideus. The dorsal half
of the muscle is superficial, but the ventral por-
1966]
Gibson: Head Muscles of Boa Constrictor
35
tion is covered by the aponeurosis of the ad-
ductor superficialis, the zygomatic ligament, and
the cervicomandibularis - neurocostomandibu-
laris aponeurosis.
Origin— (Text-fig. 1). The entire rostro-me-
dial face of the quadrate, along with all surfaces
of the free distal end of the supratemporal and
fascia of the depressor mandibulae in the region
of the quadrato-supratemporal articulation. The
tendon from the quadrate also provides for at-
tachment of fibers.
Insertion— (Text-fig. 1). The lower boundary
of the insertion of the adductor profundus fol-
lows the insertion of the adductor superficialis
and medialis, being posterior to the medialis in
the region of the coronoid process and dorsal to
the aponeurosis along the crista lateralis. The ad-
ductor profundus inserts on the lateral face of
the supra-angular from the quadrato-mandibular
articulation forward to these limits.
Innervation— A ramus emerging from the
dorsal surface of V3 passes over the lateral sur-
face of the adductor posterior and sends twigs
to both adductor profundus and posterior.
Function— Adducts the mandible, particularly
in setting the teeth firmly into the prey.
Variations.—' The group of fibers from the ten-
don on the ventro-medial face of the distal end
of the supratemporal may either pass ventral to
that bone and thence rostro-ventrad, or they may
pass dorsal to the bone. In the former case the
fibers are a part of the adductor profundus and
in the latter case they form a part of the adductor
medialis.
Other variations are described in conjunction
with adductor medialis.
2d. Adductor mandibulae internus pterygoid-
eus.— (Synonymy: Ausserer Fliigelmuskel, D’Al-
ton, 1834; transverso-maxillo-pterygo-mandibu-
laris, Bronn, 1890). (Text-fig. 1). The ptery-
goideus is a fleshy, deep-bellied muscle situated
medial to the proximal end of the mandible. Al-
though its fibers converge rostrally from the ori-
gin on the retroarticular process, they do not
form a tendon. A subdivision, pterygoideus ac-
cessorius, was not found, nor was there any
insertion of fibers onto the mucosa of the mouth.
Location— The pterygoideus covers the pos-
terior half of the ventral surface of the pterygoid
bone. The anterior two-thirds of the ventral sur-
face of the pterygoideus is covered by the mu-
cosa of the mouth and throat, while the posterior
third is in contact with the neurocostomandibu-
laris. The dorsal surface is adjacent to the mandi-
ble, the pterygoid and the adductor posterior.
Origin.— From the ventral surface of the pos-
terior tip of the ectopterygoid, caudad, covering
the ventral face of the pterygoid except for the
medial margin.
Insertion— On the retroarticular process and
the lateral, ventral and medial surfaces of the
compound bone of the mandible below the sig-
moid fossa.
Innervation.— V 3, before emerging from the
foramen, gives off from its ventral surface the
fair-sized pterygoideus nerve which passes me-
diad and ventro-caudad on the medial face of
the adductor posterior to the pterygoideus mus-
cle.
Function.— This muscle during abduction
causes a lateral movement of the distal end of the
mandible and a lateral rotation on the longitudi-
nal axis. At the same time, during protraction
of the pterygoid complex, contraction of the
pterygoideus depresses the ectopterygoid which
in turn depresses the posterior end of the maxil-
lary. This rotates the maxillary on a transverse
axis in the region of the palatine process, elevat-
ing the anterior end of the maxillary.
The pterygoideus assists in closing the mouth
and, working with the adductor profundus, exer-
cises a fine control of the rotation of the mandi-
ble.
2e. Adductor mandibulae internus temporalis
(pseudotemporalis).— (Synonymy; temporalis d,
D’Alton, 1834; parieto-mandibularis profundus,
Phisalix, 1922; temporalis anterior, Radovano-
vic, 1935; parieto-mandibular, Anthony & Serra,
1950). (Text-fig. 1). A deep adductor of the
mandible lying between the adductor medialis
and the parietal and separated from the medialis
by the maxillary branch of the trigeminal nerve,
V2. It is generally strap-shaped with a slight fan-
ning out of the fibers at their origin. The direc-
tion of the fibers is ventro-caudal.
Location— Adjacent to the parietal and con-
strictores dorsales medially and the adductor
medialis, laterally, the pseudotemporalis stretch-
es from the anterior part of the lateral face of
the parietal to the coronoid process.
Origin.— From the lateral face of the parietal
immediately below the parietal crest lying be-
tween the origin of the adductor superficialis
anteriorly and the supratemporal, posteriorly.
Insertion— On median plane of the coronoid
process and the anterior edge of the median
lamella of the mandibular fossa. There is no
fibrous insertion on the rictal plate, but the fascia
of the pseudotemporalis (anterior edge) is con-
tinuous with the median fold of the rictal plate.
Innervation— A single pseudotemporalis nerve
leaves the cranium via the posterior trigeminal
foramen ventral to the adductor superficialis
and medialis rami and passes rostro-ventrad, re-
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dividing and entering the lateral face of the mus-
cle. No pseudotemporalis ramus of the ptery-
goideus nerve was present.
Function.— An adductor of the mandible.
Variation— The fanning-out of the fibers at
their origin may be absent.
CONSTRICTORES VENTRALES
3a. Intermandibularis anterior
3b. Intermandibularis posterior dorsalis
3c. Intermandibularis posterior ventralis
The three muscles in the floor of the mouth
which are innervated by the mandibular branch
of the trigeminus, V3, are classified as the con-
strictores ventrales. They are, generally, long,
thin muscles with subdivisions into various
heads. They adduct the mandibles towards the
midventral line and constrict and elevate the
floor of the mouth after it has been stretched
during the deglutition.
A pair of aponeuroses, lateral to the midven-
tral line, separate the intermandibular muscles
of the right and left sides from each other and
from the skin of the area. The aponeuroses
stretch from the anterior tip of the mandibles
back to the insertion of the intermandibularis
anterior. Laterally, they become coalesced with
the aponeurosis of the neurocostomandibularis.
This arrangement permits a wide range of inde-
pendent action between the two mandibles.
Innervation of the constrictores ventrales is
by means of the inferior dentary nerve, which
is a branch of the mandibular ramus of the
trigeminal nerve (Hoffstetter, 1939). The infe-
rior dentary nerve enters the mandibular canal
through the Meckelian foramen located within
the manibular fossa. This nerve, joined by the
chorda tympani which has entered the canal by
way of the retroarticular foramen, courses an-
teriorly along with Meckel’s cartilage. Several
sensory branches leave the inferior dentary nerve
through various foramina, including the foramen
in the angular, before the main root reaches the
splenial, where a foramen and the beginning of
the Meckelian sulcus are located. The foramen,
which is ventral to the sulcus, provides the exit
for a motor ramus of the inferior dentary nerve.
The ramus, if named according to Lakjer’s
method, would be the intermandibularis-cuta-
neous nerve. It sends ramifications to the inter-
mandibularis anterior and posterior, dorsalis
and ventralis and to the skin.
3a. Intermandibularis anterior— (Synonymy :
Die sich kreuzenden Muskeln des Unterkiefers,
D’Alton, 1834; intermaxillaris, Bronn, 1890).
The intermandibularis anterior extends from the
distal tip of the dentary caudad for about two-
thirds of the length of that bone. The fibers
run caudo-mediad, none directly mediad. There
are two heads separated at their origin by the
origin of the genioglossus. These fairly heavy
bands of muscle remain distinct except at the
insertion.
The connective tissue of the midventral line at
the insertion of the intermandibularis anterior
is continuous with a median vertical sheet of
fascia. The dorsal end of the sheet attaches to
the floor of the mouth ventral to the tongue
and ends anteriorly at the point where the tongue
is protruded from its sheath. Thus the inter-
mandibularis anterior has a connection with the
tongue sheath.
No fasciculus which inserts on the mandi-
bular gland (pars glandularis, Albright & Nelson,
1959) is formed.
Location— Most of the ventral surface of the
intermandibularis is covered by the aponeurosis
of the neurocostomandibularis; only the inser-
tion is entirely superficial and, even in this area,
a small part is medial to one head of the inter-
mandibularis posterior ventralis. The dorsal face
of the intermandibularis anterior is adjacent to
the genioglossus, geniotrachealis and the inter-
mandibularis posterior dorsalis.
Origin.— The origins of the two heads of the
intermandibularis anterior, which are on the
ventro-medial surface of the curved distal tip of
the mandible, are separated by the origin of the
genioglossus.
Insertion.— On fascia of the midventral line,
between the levels of the anterior mylohyoid
foramen and the splenio-angular suture.
Innervation. — The intermandibularis-cutane-
ous branch of the inferior dentary nerve leaves
the mandibular canal through the foramen in
the splenial, directed ventro-mediad, sending a
branch to the intermandibularis posterior ven-
tralis and the skin before dividing into two ap-
proximately equal rami. The anterior ramus
turns rostrad to send twigs into the dorso-lateral
and ventral faces of the intermandibularis ante-
rior and into the dorsal surface of the inter-
mandibularis posterior dorsalis.
Function.— Adduction of laterally displaced
distal tips of the mandibular rami, contraction
of the floor of the mouth, or protraction of the
tongue sheath and/or larynx depending on in-
teraction with other muscles.
Variations.— Some fibers may originate on the
aponeurosis of the neurocostomandibularis.
There may be much interlacing of fibers at the
insertion with the intermandibularis posterior
ventralis.
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3b. Inter mandibular is posterior dorsalis.— It is
partially embedded in loose connective tissue,
making dissection tedious. It is a better develop-
ed and apparently more specialized muscle than
the other constrictores ventrales. The two heads,
glandular and mucosa, are equal in diameter.
The fibers, originating on the midventral line
dorsal to the intermandibularis anterior, proceed
rostro-laterad to the mandible. There they turn
rostro-medial and insert on the caudal end of
the mandibular gland and the mucosa dorsal and
caudal to the gland. The fibers at the insertion
of the mucosa head fan out and form a cup-
like depression around the dorsal and dorso-
caudal portion of the gland. The intermandi-
bularis posterior dorsalis, along with the genio-
trachealis, makes an almost complete muscular
encasement for the mandibular gland.
Location.— This is a deep muscle of the ante-
rior intermandibular region. Due to the curving
course of the intermandibularis posterior dor-
salis, this muscle lies ventral to the geniotrac-
healis and genioglossus at its origin and dorsal
to them at its insertion. The fibers inserting on
the dorsal-lateral area of the mandibular gland
are covered by a glandular fasciculus from the
geniotrachealis. The medial fibers of the mucosa
head insert quite close to fibers from the anterior
segment of the geniotrachealis. Since the fibers
of both muscles are embedded in connective
tissue, it is difficult to separate them but no
fusion was found.
Origin.— On the connective tissue of the mid-
ventral line dorsal to the intermandibularis an-
terior.
Insertion.— Insertion of the mucosa head is on
an extensive area of the mucosa caudal and dor-
sal to the mandibular gland from the level of
the anterior tip of the splenial rostrad over the
caudal one-third of the gland. The glandular
head inserts on the caudal tip of the gland and
the postero-lateral third of the glandular sheath.
Innervation.— The inferior dentary nerve gives
off an intermandibularis-cutaneous ramus
through the foramen in the splenial which, after
branching to the intermandibularis posterior
ventralis and intermandibular skin, bifrucates.
The anterior bifrucation sends twigs rostrally
and medially into the dorsal surface of the inter-
mandibularis posterior dorsalis and into the in-
termandibularis anterior.
Function— The reason for such a sizable mus-
cle of this particular arrangement is not im-
mediately clear. Obviously, its action would op-
pose that of the intermandibularis anterior and
glandular fasciculus of the geniotrachealis when
these two muscles are used to protrude and ele-
vate the tongue sheath and larynx. Also the inter-
mandibularis posterior dorsalis constricts the
mandibular gland, but it would seem that both
of these actions could be accomplished by a
much smaller muscle unless the contents of the
gland are forcibly extruded.
Variations.— The fibers at the origin of the
intermandibularis posterior dorsalis may inter-
digitate with those from the intermandibularis
posterior ventralis which insert in the same area.
3c. Intermandibularis posterior ventralis. —
(Synonymy: Die sich kreuzenden Muskeln des
Unterkiefers, D Alton, 1834; intermandibularis
posterior, Owen, 1866; Phisalix, 1922; Anthony
& Serra, 1950; intermaxillaris, Bonn, 1890).
(Text-figs. 1 & 2). The intermandibularis poste-
rior ventralis is comprised of three extremely
long, thin, completely separated heads with
fibers directed rostro-mediad from the medial
surface of the proximal end of the mandible to
the midventral line. The superficial head is only
Wi mm. wide and, since it is buried in the loose
connective tissue between the skin and the neu-
rocostomandibularis, almost impossible to find.
The medial and lateral heads are medial to the
neurocostomandibularis and are much larger.
The medial and lateral heads are flattened verti-
cally at their origins.
Location.— This muscle is found in the floor
of the mouth from the proximal region of the
mandible anterior for two-thirds the length of
the bone. The superficial head of the intermandi-
bularis posterior ventralis is ventral to the neuro-
costomandibularis, while the medial and lateral
heads are dorsal to it except at their insertions,
where they also become superficial. At their
origin, the two main elements are situated be-
tween the mandible and the pterygoideus.
Origin.— The origins of the main elements of
the intermandibularis posterior ventralis are
taken from the medial surface of the mandible,
the lateral head from the ventro-medial face of
the supra-angular just posterior to the caudal tip
of the angular, and the medial head posterior
to this and dorsal to the crista lateralis which in
this area forms a ventral ridge. Both origins lie
in an antero-dorsal, caudo-ventral line, the pos-
terior one curving slightly upward. The super-
ficial head originates from the aponeurosis of
the cervicomandibularis near the antero-ventral
tip of the fibers.
Insertion.— On a superficial pad of loose con-
nective tissue on the midventral line anterior to
the hyoid apparatus beginning posteriorly at the
level of the splenial-angular suture and reaching
the level of the foremost tip of the splenial
anteriorly.
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Innervation.— From the inferior dentary nerve,
the intermandibularis-cutaneous ramus proceeds
from the mandibular canal by way of the fora-
men in the splenial, ventro-medially. The first
branch, given off close to the foramen, sends a
twig caudally along the latero-dorsal edge of the
intermandibularis posterior ventralis innervat-
ing the muscle. The other twigs from this branch
continue medially, then turn ventrally to inner-
vate the skin.
Function— The superficial head appears to be
much too weak to assist in the swallowing action
and probably only helps to constrict the skin
after the swallowing has been completed. The
main elements of the muscle, however, by con-
tracting after the prey has passed their insertion,
constrict the throat, preventing the food from
being pushed back out the mouth as the rib re-
gion is brought forward. The possibility of such
actions as the retraction of the tongue sheath
and larynx and the protrusion and adduction
(toward the midventral line) of the proximal
end of the mandible seem unlikely because the
amount of loose connective tissue at the insertion
does not give the muscle firm anchorage.
Variations.— The medial and lateral heads may
be fused at their origin, having a common origin
which may be ventro-lateral on the crista later-
alis rather than ventro-medial. The insertional
fibers may interlace with intermandibularis an-
terior and intermandibularis posterior dorsalis.
A few fibers of the medial head may originate on
the fascia of the pterygoideus.
Hyoid Musculature
4a. Depressor mandibulae
4b. Cervicomandibularis
4c. Constrictor colli
These three muscles are placed in this cate-
gory not because of any direct connection with
the hyoid apparatus but because they are in-
nervated by the facial nerve and hence may be
homologous to hyoid musculature in lower ani-
mals (Albright & Nelson, 1959). Egress for
the facial nerve is by way of the facial foramen
in the floor of the posterior trigeminal foramen.
The palatine ramus arises close to the point of
exit and passes anteriorly ventro-mediad to the
Vidian canal. The facial nerve continues gener-
ally caudo-laterad, medial to the columella, to
the ventro-medial surface of the depressor man-
dibulae. About the middle of the columella, the
facial receives a ramus communicans from the
petrosal ganglion of the glossopharyngeal nerve.
Near the posterior end of the columella, the
facial divides into three approximately equal
branches: the ventro-lateral chorda tympani
which enters a tiny foramen in the retroarticular
process and passes forward into the mandibular
canal; the middle ramus, cervicomandibularis
and constrictor colli nerve; and the dorso-medial
ramus, depressor mandibulae nerve.
The hyoid muscles are located, mainly, poste-
terior to the quadrate from the mid-dorsal line
to the quadrato-mandibular articulation. The
constrictor colli, however, reaches ventrally
around the throat to the midventral line anterior
to the quadrato-mandibular articulation.
The constrictor colli is entirely superficial, as
is most of the cervicomandibularis. The depres-
sor mandibulae lies medial to the cervicomandi-
bularis except for its dorsal area.
The depressor mandibulae and cervicomandi-
bularis act as depressors of the lower jaw and
the constrictor colli contracts the throat region.
4a. Depressor mandibulae. — (Synonymy:
Niederzieher des Unterkiefers, D’Alton, 1834;
tympanico-mandibularis, Owen, 1866; occipito-
quadrato-mandibularis, Bronn, 1890; digastric-
us, Phisalix, 1922; Radovanovic, 1935; Anthony
& Serra, 1950). (Text-figs. 1 & 2). The depressor
mandibulae is a well developed muscle posterior
to the quadrate. A strong slip extends dorsad
forming an occipital head, distinct from the
quadrate head down to the insertion. There is
a dorsal extension of the fascia of the quadrato-
mandibular articulation to which the occipital
head attaches. The sheet of fascia presents a
rostro-lateral and a caudo-medial face. Fibers
from the quadrate head insert on both faces of
the fascia.
The dorsal portion of the occipital head is
directed caudo-laterad and the remainder, ven-
tro-laterad. The quadrate head is directed ven-
tro-laterad and its fibers completely surround
the tendon of the retractor quadrati.
Location— The depressor mandibulae lies be-
neath the constrictor colli and the cervicomandi-
bularis with only the dorsal portion being super-
ficial. The occipital head reaches rostro-medially
between the cranial insertion of the spinalis-
semispinalis and the more posterior portions of
the adductor medialis. The quadrate head ad-
joins the adductor profundus anteriorly and the
retractor costae biceps posteriorly. The retractor
quadrati emerges from its origin on the quadrate
from between the fibers of the quadrate head.
Origin.— The occipital head originates from
the posterior fifth of the parietal crest. The quad-
rate head originates from a wide area on the
posterior quarter of the supratemporal and the
upper three-fourths of the caudo-lateral face of
the quadrate.
Insertion.— On the lateral and caudo-dorsal
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Gibson: Head Muscles of Boa Constrictor
39
faces of the retroarticular process and on the
sheet of fascia, which is a dorsal extension of
the quadrato-mandibular articulation capsule.
The insertion of the occipital head is on the
dorsal lateral edge of the fascia.
Innervation— Three rami of the facial nerve
are located on the ventro-medial face of the
depressor mandibulae just dorsal to the posterior
tip of the pterygoid. The dorsal ramus is the de-
pressor mandibulae nerve and it penetrates the
muscle in this region.
Function.—1 The depressor mandibulae lowers
the mandible and the occipital head pulls the
distal end of the quadrate outward from the mid-
line of the body, displacing the mandible laterad.
Variations.— The occipital head may be tendi-
nous at its origin, in which case the origin is
moved forward on the parietal crest to about the
level of the anterior border of the supratemporal.
4b. Cervicomandibularis.— (Synonymy : Nack-
enunterkiefermuskel, D’Alton, 1834; trachelo-
mastoideus, Owen, 1866). (Text-fig. 2). The
cervicomandibularis, a heavy sheet of superficial
muscle, medial to the constrictor colli only, is
located in the lateral cervical region anterior to
the neurocostomandibularis and posterior to the
quadrate. It is equal in size to the vertebral head
of the neurocostomandibularis. The fibers are
directed from a mid-dorsal aponeurosis rostro-
ventrad to the mandible. The aponeurosis by
which the cervicomandibularis originates and
inserts are both continuous with those of
the neurocostomandibularis. Also, some of the
fibers of the two muscles fuse.
The aponeurosis of the insertion of the cervi-
comandibularis is quite large, bounded by the
mid-dorsal line above and the neurocostomandi-
bularis below. It is superficial to and separate
from the fascia and aponeurosis of the adductor
externus muscles and the depressor mandibulae.
Anteriorly it attaches to the parietal, postorbital
and rictal plate. Medial to the zygomatic liga-
ment, the aponeurosis passes ventrad over the
aponeurosis of the adductor externus muscles to
become confluent with the aponeurosis of the
neurocostomandibularis. At the inferior labial
gland, the aponeurosis has two layers, forming a
pocket in which the gland lies; the lateral layer
attaches to the skin lateral to the gland, and the
medial layer to the dentary. Anterior to the gland,
the aponeurosis is again a single layer and at-
taches to the dentary. It grows firmly to the pos-
terior tip of the gland and to the skin at the angle
of the mouth ventral to the rictal plate.
The dorsal part of the aponeurosis is much
thinner than the tougher portion found ventral
to the zygomatic ligament.
Four distinct heads of the cervicomandibu-
laris insert on this aponeurosis; three principal
ones, of almost equal size, lying in a dorso-
ventral plane, are here designated as dorsal, mid-
dle and ventral heads. At the point of attachment
of the zygomatic ligament to the quadrato-man-
dibular articulation, the middle head overlies the
ventral part of the dorsal head. Also in this area,
the middle head gives rise to a much smaller and
shorter medial head which attaches to the cap-
sule of the quadrato-mandibular articulation.
Location. — Radovanovic’s (1935) method of
distinguishing the border between the cervico-
mandibularis and the vertebral head of the neu-
rocostomandibularis by using the emergence of
the retractor quadrati as a demarkation has been
followed here, in spite of the fact that there is
fusion of fibers of the two muscles dorsally.
The medial surface of the cervicomandibu-
laris is adjacent to portions of the adductor pro-
fundus, depressor mandibulae, retractor quad-
rati, pterygoideus and trunk muscles.
Origin— From the tough aponeurosis of the
mid-dorsal area and the fascia of the spinalis-
semispinalis muscle group. The origin begins an-
teriorly at approximately the level of the neural
crest of the fourth vertebra and reaches poste-
riorly to the level of the ninth vertebra.
Insertion.— The dorsal head of the cervico-
mandibularis inserts on the aponeurosis dorsal to
the attachment of the zygomatic ligament and
on the ligament, itself, as well as the capsule of
the quadrato-mandibular articulation. The mid-
dle head has an aponeurotic insertion only, and
the part of the aponeurosis to which the dorsal
fibers of the middle head attach is lateral to the
attachment and posterior end of the zygomatic
ligament. The subsidiary, medial head inserts on
the quadrato-mandibular articulation posterior
lo the attachment of the ligament.
The ventral head has its insertion on the apo-
neurosis adjacent to the vertebral head of the
neurocostomandibularis. The ventral head does
not overlap the middle head.
Innervation.— Of the three rami of the facial
nerve found on the ventro-medial face of the
depressor mandibulae, the middle one is the
cervicomandibularis-constrictor colli nerve. The
cervicomandibularis-constrictor colli nerve
branches, the dorsal branch innervating the cer-
vicomandibularis, while the ventral branch con-
tinues through this muscle into the constrictor
colli.
Function.— Contraction of the middle and
ventral heads augments the neurocostomandi-
bularis in depressing the mandibles and in swing-
ing the distal end of the mandibles outward. The
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dorsal head, by means of the insertion on the
quadrato-mandibular articulation capsule, re-
tracts the quadrate and, thus, the entire palato-
maxillary complex as well as the mandible.
Variations— The medial head may insert par-
tially with the dorsal head on the quadrato-
mandibular articulation and partially with the
middle head on the aponeurosis.
4c. Constrictor colli.— (Synonymy: Riickwart-
zieher des Zungenbeins, D’Alton, 1834; atlanto-
epistropheo-hyoideus, Bronn, 1890; intermandi-
bularis superficialis, Anthony & Serra, 1950).
(Text-fig. 2) . The constrictor colli is a thin, nar-
row band of superficial muscle. It curves from
the mid-dorsal region, around the angle of the
jaw to the midventral area. Thus the fibers are
oriented caudo-laterad dorsally and rostro-me-
diad ventrally. The muscle is embedded in the
loose connective tissue beneath the skin and is
difficult to discern.
The fibers diverge in the throat region so that
the insertion is approximately ten times broader
than the origin.
Location— The constrictor colli overlies por-
tions of the depressor mandibulae, cervicoman-
dibularis and neurocostomandibularis.
Origin.— From the aponeurosis of the mid-
dorsal line overlying the spinalis-semispinalis
muscles and the deeper fascia with which the
aponeurosis is continuous, between the depressor
mandibulae and the cervicomandibularis. The
fibers do not extend to the mid-dorsal line.
Insertion.— On fascia near the midventral line
and on the dense fibrous connective tissue shield
found at the level of the larynx.
Innervation.— The ventral branch of the cer-
vicomandibularis-constrictor colli nerve passes
through the fibers of the cervicomandibularis
muscle and piercing the medial surface of the
constrictor colli slightly medial and caudo-dorsal
to the retroarticular process, innervates that
muscle.
Function.— The constrictor colli may not be as
weak and ineffectual as has been supposed. Be-
cause it is attached to inelastic tissues at its origin
and half of its insertion, its action must be one
of constriction. The throat, enlarged by the pas-
sage of food, would not offer any resistance to
this action and so a large muscle would not be
necessary. The constriction of the skin in the
area is secondary since the muscle is attached to
the skin by loose connective tissue only, except
for part of the insertion. The constriction action
is also used during the swallowing process. When
the throat has been enlarged and the floor of the
buccal cavity and anterior end of the oesophagus
displaced caudally by the passage of food, then
the constrictor colli, retractor quadrati and inter-
mandibular portion of the neurocostomandibu-
laris pull the skin forward over the prey, spread-
ing the two segments of the hyoid apparatus lat-
erad and dorsad.
Hypobranchial-spinal Musculature
5a. Hyoglossus
5b. Hyotrachealis
5c. Genioglossus
5d. Geniotrachealis
5e. Neurocostomandibularis
5f. Retractor quadrati
These muscles, grouped according to Albright
& Nelson (1959), include those innervated by
the glossopharyngeal, vagus, accessorius, hypo-
glossal and the first spinal nerves. Here, the
muscles of the neck region not concerned with
deglutition have been omitted. The innervation,
due to much mixing of fibers, is confusing and
has not been satisfactorily worked out.
All muscles of this group are flat, either fan-
shaped or bands. They are located in the lateral
cervical region posterior to the quadrate, and the
throat and intermandibular regions.
The four extrinsic muscles of the tongue and
larynx move those organs while the neurocosto-
mandibularis abducts the mandible and the re-
tractor quadrati acts on the hyoid and the skin.
The pathways of the glossopharyngeal, acces-
sorio-vagus, hypoglossal, and first and second
spinal nerves, and the lateral superficial cervical
trunk (sympathetic) are so interwoven and in
many places confluent, that it is necessary to de-
scribe all of them in order to make clear which
nerve is being discussed. The identification of
these nerves was accomplished through the use
of Owen (1866), Bronn (1890), Hoffstetter
(1939) and Oelrich (1956). Oelrich has de-
scribed the nerves of Ctenosaura in more detail
than the other author, and where the nerves of
Boa have had a distribution closely following
that of Ctenosaura, it has been assumed that the
nerves were made up of the same components
as those of Ctenosaura. It is realized, of course,
that this is a shaky basis for such an assumption
but, lacking a microscopic study of the nerves,
the best that can be done. Bronn ( 1890, p. 1486)
states that the Xth and Xlth cranial nerves are
always fused in snakes, so all references to the
vagus herein will mean the combined accessorio-
vagus.
The glossopharyngeal and vagus nerves,
bound together by a connective tissue sheath,
emerge from the skull through the jugular fora-
men in the exoccipital. The glossopharyngeal
nerve itself is small, but here it is accompanied
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Gibson: Head Muscles of Boa Constrictor
41
by many sympathetic fibers so that it is as large
as the vagus. The glossopharyngeal nerve, dorsal
to the vagus at the jugular foramen, enlarges into
the petrosal ganglion not far from the skull. At
the ganglion, the vagus lies medial to the glosso-
pharyngeal and the two nerves become fused in
the posterior part of the ganglion. Dorsally the
petrosal ganglion has two rami communicating
with the facial nerve; an antero-medial one to
the chorda tympani in the region of the colu-
mella, and one which goes antero-ventrally over
the lateral face of the ganglion to join the pala-
tine ramus of the facial. The hypoglossal nerve
issues from the skull via three small foramina in
the exoccipital which are connected by canals
within the bone. Outside the skull, the rami of
the hypoglossal fuse and receive fibers from the
first two spinal nerves. The deep cervical sym-
pathetic trunk, which connects the spinal nerves
close to the vertebrae, sends a terminal ramus
from the first spinal nerve antero-laterad to the
vagus quite near the jugular foramen. The term-
inal ramus is joined by a communicating ramus
from the hypoglossal before entering the vagus.
At this locus, the vagus has a communicating
ramus with the glossopharyngeal and another
with the hypoglossal. The combined hypoglosso-
spinal nerve coalesces with the vagus posterior
to the petrosal ganglion. Posteriorly from the
ganglion issue three main nerve roots which may
be fused for a short distance.
The three roots, the glossopharyngeo-vagal,
the vago-hypoglosso-spinal, and the vago-sym-
pathetic, proceed caudo-laterally and slightly
ventrally to the region of the posterior tip of the
pterygoid, where they swing more ventrad to
the mandibular area. The lateral superficial cer-
vical trunk, which is the sympathetic part of the
vago-sympathetic root, turns caudad between
the carotid artery and the jugular vein, the vagal
part of the root having previously separated from
the root and gone to the pharynx and trachea.
The other roots, the glossopharyngeo-vagal and
the vago-hypoglosso-spinal, turn rostrally and
run ventral to the mucosa between the mandible
and the trachea. Along the intermandibular
course, there is a short space in which the two
roots are fused, but subsequent distribution does
not indicate that there is any crossing of fibers.
5a. Hyoglossus. — (Synonymy: Zungenbein-
muskel, D’Alton, 1834). The hyoglossus is an-
other long, thin band of muscle which is flat
from its origin to the region of the tongue sheath,
where it becomes more circular in cross-section.
The fibers originate from the posterior tip of the
hyoid apparatus and follow the rostro-medial
course of the hyoid. Anteriorly, the muscle en-
ters the tongue sheath and becomes the intrinsic
muscle of the tongue (Albright & Nelson, 1959).
An element of the neurocostomandibularis,
which arises posterior to the hyoid, partially in-
serts on the fascia of the hyoglossus in the ven-
tral portion of the origin of the latter muscle.
Fibers of the dorsal portion of the origin of the
hyoglossus are continuous with the neurocosto-
mandibularis. Only an inscription intervenes.
Location— Ventral to the hyoid, oesophagus
and trachea; between these structures and the
neurocostomandibularis.
Origin— From the posterior one-eighth of the
hyoid apparatus. The origin surrounds the hyoid
except for its midventral area. From the mid-
ventral area, half of the fibers are directed lat-
erad and half mediad before they turn rostro-
rnediad and join ventral to the hyoid.
Insertion— In the tongue sheath.
Innervation. — The glossopharyngeo - vagal
nerve root, shortly after turning rostrad in the
intermandibular region, gives off a fairly promi-
nent branch of glossopharyngeal fibers, the lin-
gual ramus. The lingual ramus follows the main
root rostrad for some distance before turning
mediad to send several small rami into the hypo-
glossus. The principal part of the lingual ramus
proceeds rostrad along the dorso-lateral surface
of the hyoglossus and into the tongue sheath,
where it eventually embeds in the muscle. The
intrinsic tongue muscles are also innervated by
the lingual ramus of the inferior dentary nerve
of the trigeminal (carrying chorda tympani fi-
bers), which emerges from the beginning of the
Meckelian sulcus in the splenial and joins an
anterior ramus of the vago-hypoglosso-spinal
nerve. Presumably the fibers from the vago-
hypoglosso-spinal going to the tongue muscles
are hypoglossal. A second, very small twig from
the vago-hypoglosso-spinal nerve follows the an-
terior ramus into the tongue but does not fuse
with the others.
Function— Intrinsic tongue movements.
5b. Hyotrachealis ( Synonymy : Riickwart-
zieher des Kehlkopfs, D’Alton, 1834; hyoideo-
laryngeus, Bronn, 1890). (Text-fig. 1). The
hyotrachealis is a long strap of muscle passing
from the hyoid rostro-mediad to the larynx, dor-
sal to the geniotrachealis.
Location.— On the ventral surface of the mu-
cosa of the mouth and oesophagus except in the
region of its insertion, where it swings ventrad
to the larynx. The muscle is dorsal to the neuro-
costomandibularis and crosses the geniotrachea-
lis dorsally. At the origin of the muscle, the ptery-
goideus lies between it and the mucosa.
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Origin— From the rostro-lateral face of the
hyoid apparatus.
Insertion.— On the ventro-lateral and ventral
faces of the laryngeal cartilages. The pair of
hyotracheales almost meet midventrally.
Innervation.— Posterior to the point of fusion
of the vago-hypoglosso-spinal and the glosso-
pharyngeo-vagal nerves in the intermandibular
region, the vago-hypoglosso-spinal nerve gives
off a small ramus. The ramus sends very fine but
long twigs to connective tissues around the blood
vessels of the region and then continues medially
to innervate the hyotrachealis. Anterior to the
area of fusion, the glossopharyngeo-vagal nerve
sends very small branches into the hyotrachealis.
It may be that the ramus from the vago-hypo-
glosso-spinal nerve, since it does have fibers go-
ing to connective tissue and/or blood vessels, is
autonomic (Xth) and not motor.
Function— Either retraction of the larynx or
protraction of the hyoid, depending on the action
of associated muscles.
Variations— The origin of the hyotrachealis
from the hyoid may be confined to a few fibers
with the majority of the fibers arising from an in-
scription in the neurocostomandibularis. The
inscription is rostro-lateral to the origin of the
fibers from the hyoid. Some fibers do not origi-
nate in this area but come from some point far
caudal (the head was severed too far anteriorly
to be able to follow these fibers to their origin.
CNHM 31700). Although individual fasciculi
could be followed for some distance caudad, the
hyotrachealis was not entirely separable from the
neurocostomandibularis posterior to the hyoid.
There may be a coalescence of fibers of the
geniotrachealis and hyotrachealis.
5c. Genioglossus. — (Synonymy: Vorwartzie-
her des Zungenbeins, D’Alton, 1834; maxillo-
hyoideus, Bronn, 1890). The genioglossus is a
long muscle stretching caudo-medially from the
anterior tip of the dentary to the posterior ex-
tremity of the tongue sheath. It is flattened be-
tween the tongue sheath and the geniotrachealis.
The original area on the dentary is small, but at
the insertion the muscle fans out, almost sur-
rounding the tongue sheath. Since some of the
fibers insert on the fascia of the hyoglossus, they
give the appearance of being continuous with
the hyoglossus, but no fusion occurs.
Location.— This is a muscle of the deep, ante-
rior intermandibular region. The anterior quar-
ter of the genioglossus lies between the two
heads of the anterior intermandibularis for the
most part, with only a small portion of the dorsal
surface in contact with the geniotrachealis.
Caudally, the geniotrachealis swings slightly
ventrad to lie lateral to the compressed genio-
glossus, leaving the dorsal surfaces of both
muscles in contact with the mucosa. The middle
third of the genioglossus is covered with the
mucosa. The middle third of the genioglossus is
covered ventrally by the insertion of the inter-
mandibularis posterior ventralis. Here the genio-
glossus adheres closely to the tongue sheath,
as it does for the remainder of its length.
Origin.— On the ventro-medial plane of the
anterior curved tip of the mandible.
Insertion.— On the tongue sheath, from the
level of the posterior mylohyoid foramen (Oel-
rich, 1956) in the angular caudad to the level
of the last labial. In this area the fascia of the
genioglossus merges with the tongue sheath. The
insertion covers the tongue sheath from the mid-
ventral to almost the mid-dorsal line.
Innervation.— The anterior termination of the
vago-hypoglosso-spinal nerve root is a number
of anterior rami of hypoglossal fibers located
postero-Iateral to the larynx. One of these an-
terior rami turns sharply mediad, anterior to
the combined lingual ramus of the trigeminal
and an anterior ramus of the vago-hypoglosso-
spinal, and sends branches into both the genio-
glossus and geniotrachealis.
Function.— Protracts the tongue sheath.
Variations.— A small slip of the genioglossus
may separate from the main muscle mass and
insert on the tongue sheath anterior to the rest.
This slip is enclosed by the fascia of the tongue
sheath for some distance before its insertion.
5d. Geniotrachealis— ( Synonymy: Vorwarts-
zieher des Kehlkopfs, D’Alton, 1834; maxillo-
laryngeus, Bronn, 1890). The geniotrachealis is
a much elongated muscle, circular in cross-sec-
tion, which has fibers directed caudo-mediad,
closely paralleling the genioglossus. At its origin
it is almost completely encased by the two heads
of the intermandibularis anterior. Only small
ventral and dorsal areas are adjacent to the genio-
glossus and the mucosa of the mouth, respec-
tively.
Location.— This is another muscle of the deep,
anterior intermandibular region. The middle
portion of the geniotrachealis is ventral to the
mucosa and the mandibular gland, while the
posterior portion passes ventral to the hyotra-
chealis also. It is dorsal to the neurocostomandi-
bularis, intermandibularis anterior and genio-
glossus, as well as portions of the intermandi-
bularis posterior dorsalis and ventralis.
Origin— From the dentary on the medial sur-
face just ventral to the second or third tooth
socket.
Insertion— On the lateral and dorso-lateral
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Gibson: Head Muscles of Boa Constrictor
43
and dorsal walls of the trachea between the levels
of the anterior mylohyoid foramen in the sple-
nial and the posterior mylohyoid foramen in the
angular.
Innervation.— Three of the anterior rami of
hypoglossal fibers from the vago-hypoglosso-
spinal nerve turn mediad to innervate the genio-
trachealis. The most anterior ramus also sends
branches to the genioglossus.
Function.— Protracts the larynx
Variations.— The geniotrachealis varies from
a simple column of muscle to a complex of
branching segments and coalescing fibers. The
fibers of the geniotrachealis and hyotrachealis
may unite where the two muscles are in contact.
Anterior and dorsal to this, the geniotrachealis
may be joined by a dorsal segment which is as
large as the principal part of the muscle. The
dorsal segment arises from the dentary just dor-
sal to the origin of the main element of the mus-
cle. Many fibers insert on the mucosa postero-
medial to the mandibular gland, intermingling
with fibers from a fasciculus of the intermandi-
bularis posterior dorsalis, to which they seem to
fuse but do not. Most of the fibers of the dorsal
segment join the main head near its insertion.
Near the anterior end of the mandibular gland,
two prominent fasciculi leave the dorsal segment
and are directed caudo-laterad to the mandibular
gland. Fasciculus one and two originate from the
dentary antero-dorsal to the origin of the main
portion of the geniotrachealis and its dorsal seg-
ment and from the mucosa immediately caudo-
dorsal to this area. The fibers of fasciculus one
and the dorsal segment unite in this region. The
fibers of fasciculus one pass caudad over the
ventral surface of the mandibular gland and
some become embedded in the fibrous capsule
of the gland while others, after passing dorsad
around the postero-medial end of the gland,
turn anteriorly and fan out to insert on the mu-
cosa dorsal to the gland. One group of fibers
from fasciculus one maintains a more medial
course, not passing closely around the end of the
gland, but curving broadly to insert on the mu-
cosa dorsal and dorso-medial to the gland. This
insertion meets that of a portion of the inter-
mandibularis posterior dorsalis and the two mus-
cles form a cup in which the posterior portion
of the gland lies.
Fasciculus two lies dorsal to fasciculus one
and their fibers follow a parallel course until
the posterior third of the mandibular gland is
reached. There, fasciculus two curves sharply
laterad, closely applied to the gland, and encir-
cles the gland almost completely, to insert on
the dorso-medial face of the gland sheath. The
gland, its sheath and the glandular head of the
intermandibularis posterior dorsalis are enclosed
by fasciculus two. A small portion of the fibers
from fasciculus two follows fasciculus one and
inserts in the mucosa dorsal to the gland.
5e. Neurocostomandibularis. — (Synonymy:
Nackenunterkiefermuskel (part) and Kiefer-
zungenbeinmuskel (part), O’Alton, 1834; neuro-
mandibularis, costo-mandibularis, and mylohy-
oideus, Owen, 1866; Phisalix, 1922; cervico-
mandibularis and mylohyoideus, Bronn, 1890;
neuro-mandibularis and costomandibularis, Rad-
ovanovic, 1935; neuro-mandibularis, rectus sys-
tem, and branchiomandibularis spinalis,
Lubosch, 1938; vertebro-mandibularis, costo-
mandibularis, and mylohyoideus, Anthony &
Serra, 1950). (Text-figs. 1 & 2). This is a com-
plex muscle with numerous origins and inser-
tions. It covers the lateral cervical, throat, and
intermandibular regions and is superficial except
for the constrictor colli, the superficial head of
the intermandibularis posterior ventralis, and a
portion of the retractor quadrati.
The aponeurosis by which the neurocostoman-
dibularis inserts on the mandible lies medial to
the aponeurosis of the cervicomandibularis.
Most of the neurocostomandibularis aponeurosis
inserts on the lateral face of the dentary and
compound bone ventral to the infralabial gland,
and along this portion of its insertion it is fused
with the cervicomandibularis aponeurosis. At
the two extremities of the gland, the neurocosto-
mandibularis aponeurosis passes medial to the
gland and at the angle of the mouth it fuses with
the submucosa. Anterior to the gland the two
aponeuroses fuse and attach to the dentary.
Of the various heads, vertebral, hyoid, costal
and cutaneous, described for Thamnophis
(Cowan & Hick, 1951) and Elaphe obsoleta
(Albright & Nelson, 1959), only the vertebral
and costal heads are discrete in Boa constrictor.
In the throat region there is no distinct separa-
tion of body musculature and the neurocosto-
mandibularis.
There are two well-defined inscriptions, the
anterior one located at about mid-point on the
hyoid apparatus, and a complex, more posterior
one found at the posterior tip of the hyoid. The
complex is pectinate and lies at an angle running
antero-dorsad from the hyoid to the region of
the retroarticular process, bisecting the verte-
bral head. There are three small offshoots of the
main inscription which receive numerous fascic-
uli from several different muscles and tend to
divide the vertebral head into layers. The dorsal
offshoot receives four different muscle bundles:
a slip from the medial surface of the retractor
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quadrati, costal head of the neurocostomandi-
bularis, vertebral head, and a bundle which
passes anteriorly to the intermandibular section
of the neurocostomandibularis. The two ventral
offshoots receive all of these plus fasciculi from
the costocutaneous superior. The inscription
continues antero-mediad from the posterior tip
of the hyoid almost to the midventral line. This
part of the inscription does not branch. Near
the posterior tip of the hyoid, fasciculi from the
retractor quadrati, costal head of the neurocosto-
mandibularis (but not from the vertebral head),
costocutaneous superior, and a segment which
goes anteriorly to the intermandibular section
of the neurocostomandibularis attach to the un-
branched portion of the inscription complex.
Some of the fibers of the intermandibular part
of the neurocostomandibularis, which arise from
the inscription complex, insert on the hyoid and
the rest on the anterior inscription. A few may
continue across the anterior inscription to the
aponeurosis, but the inscription appears to bisect
the fibers of the intermandibular region com-
pletely and anchor medially to the anterior edge
of the first rib.
The innervation of the neurocostomandibu-
laris indicates that this is a composite muscle,
as is suggested by the extensiveness of the muscle
and the inscriptions within it. The fibers of the
neurocostomandibularis in the mandibular re-
gion (that is, anterior to the posterior inscrip-
tion, and between the hyoid and mandible) are
supplied by branches from the glossopharyngeo-
vagal nerve. Near the point where the nerves
and vessels turn rostrad into the intermandibular
area, the fibers are innervated by a long, fairly
large nerve which arises near the petrosal gang-
lion. Because of the fusion of the nerve roots,
it was not clear whether the long ramus came
from the glossopharyngeo-vagus or the vago-
hypoglosso-spinal nerve. It is likely that the
ramus is composed either of vagus or spinal
nerve libers. The vertebral head, costal head, and
the fibers of the neurocostomandibularis lying
postero-medial to the hyoid are innervated by
spinal nerves.
Vertebral Head.— This head is found in the
lateral cervical region posterior to the cervico-
mandibularis. The fibers, coming from a dorsal
aponeurosis, converge slightly as they pass an-
tero-ventrad around the retroarticular process
into the intermandibular area where they be-
come indistinguishable from fibers from other
origins.
Origin of Vertebral Head— On an aponeurosis
from the neural crests of the eighth to the thir-
teenth vertebrae. The aponeurosis covers the
spinal-semispinalis muscles.
Insertion of the Vertebral Head— On the in-
scription complex, or, if the inscription is inter-
preted as interrupting but not terminating the
fibers, the insertion would then be by the apo-
neurosis attached to the mandible.
Innervation of the Vertebral Head.— Branches
of the fifth and sixth spinal nerves enter the
ventral surface near the posterior inscription.
Costal Head.— The costal head is a deep-lying
portion of the muscle, occupying a position from
the twelfth rib anterior to the inscription com-
plex and medial to the vertebral head and the
costocutaneous superior. The medial surface of
the costal head is adjacent to the oesophagus.
The costal head represents the anterior fiber
bundles of the costocutaneous inferior which, in
the body region, arise from the tips of the ribs
and proceed craniad to insert on the fascia of
the medial surface of the costocutaneous su-
perior. From the twelfth rib forward the inser-
tion is changed, forming the costal head even
though no definite fascial space separated this
head from the costocutaneous inferior proper.
The fibers arising from each rib remain discrete
bundles, making it possible to determine the
extent of the two muscles.
Origin of the Costal Head.— From the extreme
tips of the first twelve ribs.
Insertion of the Costal Head— From the first
eleven ribs, the fiber bundles pass craniad to
insert on the inscription complex. The fibers
from the twelfth rib insert on the medial surface
of the posterior tip of the hyoid. This insertion
separates this bundle from both the costocutane-
ous inferior and the costal head but has been
included with the costal head here for the sake
of convenience.
Innervation of the Costal Head.— The rami of
the spinal nerves, beginning with the fifth, pass-
ing over the medial surface of the costal head,
give off very fine twigs to the muscle. The fifth
to the tenth spinal nerves follow this pattern,
but the number of nerves involved undoubtedly
varies.
Intermandibular Portion of the Neurocosto-
mandibularis —The term, intermandibular por-
tion, while admittedly unsatisfactory, is used in
the absence of definable heads and delimitations
from the body musculature. As used here, it will
include the area between the mandibles and back
to the posterior end of the hyoid.
The costocutaneous superior is a large mass
of body muscle formed by bundles running from
the lateral surface of the ribs caudad to the lat-
eral edges of the gastrosteges. Anterior to the
ribs, the origins are switched to various struc-
tures. Two bundles arise from offshoots of the
1966]
Gibson: Head Muscles of Boa Constrictor
45
inscription complex, and larger groups of fibers
come from the ventro-medial part of the main
line of the inscription complex, the hyoid, and
the anterior inscription.
There is so much fusion of fibers from this
muscle and the intermandibular portion of the
neurocostomandibularis that no distinction can
be made and origins and insertions become con-
fused. Fibers of the lateral part of the inter-
mandibular portion begin at the inscription com-
plex and proceed craniad to the aponeurosis, but
toward the midventral line they arise from the
hyoid and fuse rostrally with other fibers which
lie between gastrosteges, posteriorly, and the
anterior inscription or hyoid, anteriorly.
Innervation of the Intermandibular Portion of
the Neurocostomandibularis.— The nerve supply
for the neurocostomandibularis medial and an-
terior to the posterior inscription is varied. Pos-
tero-medial to the hyoid, it is innervated by the
fifth, sixth and seventh spinal nerves. Since the
transition from neurocostomandibularis to cos-
tocutaneous superior is gradual, it is impossible
to say how many more spinal nerves are in-
volved. The area dorso-lateral to the point where
the nerves and vessels turn rostrad into the inter-
mandibular region is supplied by the long ramus
which arises from the nerve roots just posterior
to the petrosal ganglion.
Function of the Neurocostomandibularis.—
Primarily a depressor of the mandible. However,
when the mandibles are held stationary with the
teeth embedded in the prey, the action of the
muscle is more complicated. As the head of the
prey is moved from the buccal cavity into the
oesophagus, the mandibular action is supplanted
by contraction of throat muscles. Whereas the
skin and intermandibular muscles have been re-
laxed to permit the extensive stretching necessary
to get the prey in the mouth, now the intermandi-
bular portion of the neurocostomandibularis
contracts, bringing the skin and hyoid apparatus
forward over the prey. Because of the lateral
flare of the posterior part of the hyoid, the action
produces a constriction of the throat laterally,
leaving the ventral part free to stretch over the
prey and not constricting the total diameter,
which would tend to expel the prey. The laterad
and dorsad swing of the posterior tip of the
hyoid is augmented by the contraction of the
retractor quadrati. The costal head of the neuro-
costomandibularis pulls the tips of the anterior
ribs forward and outward, enlarging the diameter
of the oesophagus either so that food can slip
on down, or, after the head of the prey has
passed this point, to get a “grip” on the prey in
order to pull it further into the oesophagus. After
the head of the prey has passed the first ribs, the
costocutaneous superior, anterior part, is also
used in pulling the skin forward over the prey.
Variations of the N eurocostomandibularis.—
The costal head may involve varying numbers
of ribs and the bundles from the ribs may not
be discrete, in which case the fasciculi inserting
on the offshoots of the inscription complex are
not so well defined and the whole costal head
tends to be inserted on the inscription medial to
the vertebral head. This almost eliminates the
overlapping layers of the vertebral head. The
number of offshoots which receive fasciculi from
the costocutaneous superior may vary. It may
be that age determines how well defined the
branches of the inscription complex are; in the
older snakes the additional growth of connective
tissue may obscure the original pattern.
The exact number of branches of the inscrip-
tion complex receiving fasciculi from the retrac-
tor quadrati was most difficult to determine and
may be variable.
5f. Retractor quadrati. — (Synonymy: Riick-
wartzieher des quadratum, D’Alton, 1834; cer-
vico-squamosal, Phisalix, 1922; cervico-supra-
temporal, Anthony & Serra, 1950). (Text-figs.
1 & 2) . This muscle of the lateral cervical region
forms a strong fibrous cord proximally, which
lies deep to the cervicomandibularis, and a su-
perficial fan-shaped distal area. The distal por-
tion overlies the neurocostomandibularis and
the inscription complex. The fibers radiate pos-
tero-ventrad, ventrad and rosto-ventrad.
Medially, the retractor quadrati gives off an
element which subdivides into four or five very
thin fasciculi. The fasciculi enter the vertebral
head of the neurocostomandibularis at different
levels and insert on the inscription complex.
(See neurocostomandibularis).
Location— Proximally, the retractor quadrati
is embedded in the depressor mandibulae; the
middle section is deep to the cervicomandibu-
laris and its anterior edge is in contact with the
nerves and blood vessels emerging from the cer-
vical region. Distally, the muscle is superficial to
the neurocostomandibularis except where the
medial fasciculi penetrate it.
Origin— By a short tendon from the proximal
end of the postero-lateral face of the quadrate
near its medial border.
Insertion.— On fascia attached to the skin
which follows the contours of the hyoid and on
the skin.
Innervation— The third and fourth spinal
nerves send rami laterad in the triangular area
of fascia, vessels and nerves located posterior to
the retroarticular process. The rami from the
two spinal nerves branch medial to the retractor
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[51: 3
quadrati and the branches coalesce before enter-
ing the muscle. The fifth spinal nerve pierces
the retractor quadrati but does not supply the
muscle.
Function— The retractor quadrati supple-
ments the action of the intermandibular portion
of the neurocostomandibularis and constrictor
colli in pulling the skin of the lateral neck region
and hyoid upward and forward over the prey.
It is doubtful that this muscle actually retracts
the quadrate because of the position of the origin.
Variations— The number of fasciculi entering
the vertebral head of the neurocostomandibu-
laris varies, or it may be that in smaller speci-
mens the fasciculi are so small that they are
missed.
Summary
The adductor mandibulae externi do not ex-
hibit the degree of differentiation that is found
in Colubrid snakes (Albright & Nelson, 1959;
Cowan & Hick, 1951). There is some fusion of
fibers in the dorsal area of the adjoining surfaces
of the adductor mandibulae externus medialis
and profundus. The adductor profundus is sepa-
rated from the underlying adductor posterior
only in the region in which the nerve V3 pene-
trates. There is no protractor quadrati formed in
Boa constrictor. The intermandibular posterior
dorsalis and the geniotrachealis develop seg-
ments which insert on the mucosa dorsal, dorso-
lateral and dorso-medial to the mandibular
gland. The segments form a depression in which
the posterior portion of the gland fits. The genio-
trachealis also has segments which surround the
posterior half of the gland and attach to it. The
intermandibularis posterior dorsalis also forms
a glandular head which inserts directly to the
caudal end of the gland. A very thin, obscure,
superficial head of the intermandibularis poste-
rior ventralis follows the course of the rest of the
muscle but lies ventral to the neurocostomandi-
bularis. A constrictor colli was found in all spec-
imens examined. In the region of the posterior
attachment of the zygomatic ligament, the cervi-
comandibularis forms several separate heads.
They insert on the aponeurosis and on the quad-
rato-mandibular articulation capsule. The costo-
cutaneous superior takes its origins from the ribs
and courses caudad to insert on the gastrosteges.
Anterior to the ribs, the origins are shifted to the
inscriptions in the neurocostomandibularis and
the hyoid. The more medial portions of the mus-
cle fuse with the intermandibular portion of the
neurocostomandibularis making separation of
the two muscles impossible. The retractor quad-
rati forms several small medial slips which pene-
trate the neurocostomandibularis and insert on
the inscription complex in that muscle. The in-
scription complex also receives heads from the
costocutaneous inferior and the costocutaneous
superior.
The innervation of the adductores mandibu-
lae is afforded by seven rami which separate from
Vs just before or just after it emerges from the
posterior trigeminal foramen. One ramus is the
adductor superficialis nerve; three constitute the
adductor medialis nerve; one is the pseudotem-
poralis nerve; one is the adductor profundus and
posterior nerve, and one is the pterygoideus
nerve. The three rami constituting V4 separate
from V3 within the cranium and emerge from
small foramina ventral and rostro-ventral to the
posterior trigeminal foramen. These rami are the
retractor pterygoidei and retractor vomeris
nerve, the protractor pterygoidei nerve and the
protractor and levator pterygoidei nerve.
The main ramus of Vs enters the mandibular
canal to become the inferior dentary nerve. A
branch of the inferior dentary nerve, the inter-
mandibularis-cutaneous nerve, leaves the canal
by way of the foramen in the splenial to supply
the intermandibularis anterior and posterior,
dorsalis and ventralis, and the skin.
The hyoid musculature— that is, the depressor
mandibulae, cervicomandibularis and constrictor
colli— is innervated by rami which diverge, along
with the chorda tympani, from the facial nerve
in the region just medial to the columella.
Innervation of the hypobranchial-spinal mus-
culature because of mixing of the fibers of the
glossopharyngeal, vagus, accessorious, hypo-
glossal and spinal nerves is confusing. There is
much doubt as to the origin of the fibers making
up the rami to the muscles. A lingual ramus
from the glossopharyngeo-vagal nerve trunk
supplies the posterior region of the hyoglossus
while a ramus formed from the fusion of a
ramus lingualis lateralis (from the vago-hypo-
glosso-spinal trunk) and a lingual ramus (from
the inferior dentary nerve) enters the intrinsic
muscles of the tongue more anteriorly. Twigs
from both the vago-hypoglosso-spinal and the
glossopharyngeo-vagal trunk enter the hyotra-
chealis. Hypoglossal fibers from the vago-hypo-
glosso-spinal trunk supply both the genioglossus
and the geniotrachealis. The neurocostomandi-
bularis receives nerves from several sources:
spinal nerves, a ramus from the glossopharyngeo-
vagal trunk and a long ramus, which originates
just posterior to the petrosal ganglion. Because
of fusion of nerves in the region of the petrosal
ganglion, it could not be determined whether the
long ramus arose from the glossopharyngeo-
vagal or the vago-hypoglosso-spinal trunk. The
retractor quadrati is innervated by spinal nerves.
1966]
Gibson: Head Muscles of Boa Constrictor
47
The constrictores dorsales control movements
of the visceral skeleton. The adductores mandi-
bulae assist in the rotation of the mandible on its
longitudinal axis, as well as adducting the mandi-
ble. The constrictores ventrales constrict and
elevate the floor of the mouth and adduct the
mandibles towards the midventral line. The
hyoid musculature depresses the lower jaw and
contracts the throat region. The hypobranchial-
spinal musculature provides movement for the
larynx, intrinsic and extrinsic movements of the
tongue, abduction of the mandible and hyoid
and contraction of the skin.
Acknowledgments
The kind cooperation of many persons and
several institutions has been gratefully accepted.
The National Science Foundation has generously
supported the work through Grant-14575, while
Dr. D. D. Davis and the Chicago Natural His-
tory Museum have supplied laboratory space,
specimens, and invaluable advice. Dr. Herndon
G. Dowling, New York Zoological Park, first
suggested the problem, donated specimens and
lent his patient guidance throughout. Apprecia-
tion is also extended to Dr. Robert Inger of the
Chicago Natural History Museum and Dr. Rich-
ard Zweifel of the American Museum of Natural
History for specimens loaned.
Literature Cited
Albright, R. G., & E. M. Nelson
1959. Cranial kinetics of the generalized colu-
brid snake Elaphe obsoleta quadrivittata.
I. Descriptive morphology. II. Functional
morphology. J. Morph., Vol. 105, no. 2.
pp. 193-292.
Anthony, J., & R. G. Serra
1950. Anatomie de l’appareil de la morsure chez
Eunectes murimis L. (Boidae) . Osteologie,
myologie, vaisseux et nerfs. Revista Brasi-
leira de Biologia, Vol. 10, no. 2. pp. 23-44.
Brongersma, L. D.
1951. Some remarks on the pulmonary artery
in snakes with two lungs. Zoologische
Verhandelingen, 14: 1-35.
Bronn, H. G.
1890. Klassen und Ordnungen des Thier-reichs.
Band VI, Abthlg. 3, Leipzig and Heidel-
berg, C. F. Winter’sche Verlagshandlung.
Cowan, I. M., & W. B. M. Hick
1951. A comparative study of the myology of
the head region in three species of Tham-
nophis (Reptilia, Ophidia). Trans. Royal
Soc. Lond., 45: 19-60.
D’Alton, E.
1834. Beschreibung des muskelsystems eines Py-
thon bivittatus. Archiv fiir Anatomie,
Physiologie und Wissenschaftliche Medi-
cin. (Johannes Muller), 7: 346-64; 10:
432-50; 12: 528-43.
Dowling, H. G.
1959. Classification of the Serpentes: A critical
review. Copeia, 1: 38-52.
Dowling, H. G., & J. M. Savage
1960. A guide to the snake hemipenis: a survey
of basic structure and systematic charac-
teristics Zoologica, Vol. 45, part 1. pp. 17-
28.
Frazetta, T. H.
1959. Studies on the morphology and function
of the skull in the Boidae (Serpentes).
Part I. Cranial differences between Python
sebae and Epicrates cenchris. Bull. Mus.
Comp. Zool., 119: 453-472.
Haas, G.
1955. The systematic position of Loxocemus bi-
color Cope (Ophidia). American Museum
Novitates, N. 1748. pp. 1-8.
Hoffstetter, R.
1939. Contribution a l’etude des Elapidae actuels
et fossiles et de l’osteologie des ophidiens.
Archives du Museum d’ Histoire Naturelle
de Lyon, 15: 1-78.
Jacquart, H.
1855. Memoire sur les organes de la circulation
chez les serpents. Python. Annales des
Sciences Naturelles, 4: 321-325.
Kochva, E.
1962. On the lateral jaw musculature of the
Solenoglypha with remarks on some other
snakes. J. Morph., Vol. 110, no. 2. pp. 227-
284.
Lakjer, M. T.
1926. Studien fiber die Trigeminus-versorgte
Kaumuskulatur der Sauropsiden. Copen-
hagen, C. A. Reitzel.
Lubosch, W.
1938. Amphibien und Sauropsiden. In “Hand-
buch der Vergleichenden Anatomie der
Wirbeltiere. Vol. 5.” L. Bolk, E. Goppert,
E. Kallius, and W. Lubosch. Berlin und
Vienna, Urban und Schwarzenberg.
Oelrich, T. M.
1956. The anatomy of the head of Ctenosaura
pectinata (Iguanidae). Miscellaneous Pub-
lications. Museum of Zoology, University
of Michigan, No. 94. pp. 1-122.
48
Zoolog ica: New York Zoological Society
[51: 3
Owen, R.
1866. Anatomy of Vertebrates. Vol. 1. London,
Longmans, Green and Co.
Phisalix, M.
1922. Animaux Venimeux et Venins. Paris, Mas-
son et Cie.
1935. Anatomische studien am schlangen kopf.
Jenaische Zeitschrift fur Naturwissen-
schaft, 69: 321-421.
Ray, H. C.
1934.' On the arterial system of the common
Indian rat snake, P. mucosus (L). Journal
of Morphology, 56: 533-577.
Radovanovic, M.
4
The Behavior of Solenodon paradoxus in Captivity with
Comments on the Behavior of Other Insectivora
John F. Eisenberg1
Department of Zoology,
University of Maryland
&
Edwin Gould2
Department of Mental Hygiene,
Laboratory of Comparative Behavior,
Johns Hopkins University
(Plates
I. Introduction
Solenodon paradoxus, confined to the island
of Hispaniola, and S. cubanus, endemic to Cuba,
comprise the sole living members of the family
Solenodontidae. A full-grown specimen of S.
paradoxus may weigh up to 1 kgm. and attain a
head and body length of 300 mm. Although large
size and primitive molar cusp pattern have led
taxonomists to include this genus with the tenrecs
of Madagascar, further morphological studies
have led certain workers to conclude that Sol-
enodon is a primitive soricoid more closely allied
to the shrews than to the zalambdadont tenrecs
(McDowell, 1958).
The behavior of S. paradoxus was reviewed
by Dr. Erna Mohr ( 1936-38) . Since her series of
papers, however, much more has been learned
concerning the behavior of not only the soleno-
don but also the insectivores of the families
Tenrecidae and Soricidae. For this reason we felt
it would be useful to describe in detail the major
features of the solenodon’s behavior patterns and
to interpret them within a much broader theoret-
ical context than was possible thirty years ago.
Research supported by a General Research Board
Grant from the University of Maryland, together with
funds from the Department of Zoology.
2Research supported by the National Science Founda-
tion, Grant No. GB 1728, and the United States Air
Force, Grant No. AFOSR 586 64.
& II)
For comparative purposes the authors utilized
the extensive collection of living tenrecs main-
tained by Dr. Gould at Johns Hopkins Uni-
versity, and drew upon their previous behavioral
studies of insectivores, which have already been
published in part elsewhere (Eisenberg, 1964;
Gould, 1964, 1965).
II. Specimens and Maintenance
Four specimens of Solenodon paradoxus (one
male, three females) were purchased from a
dealer in the Dominican Republic. The male
(M) and one female (J) were immature and,
extrapolating from their weights (Mohr, 1936
II), were judged to be four and six months old,
respectively. The juveniles were studied as a
pair by Dr. Eisenberg. In addition, all four ani-
mals were employed in two-animal encounters
and were recorded during studies of vocal com-
munication.
For observational purposes they were kept as
pairs in 4 X 4 ft. cages having solid plywood
walls and no top. The cages were provided with
logs and pieces of sod but the floor was covered
with newspapers as a sanitary precaution, since
the animals were prone to scatter their food on
the cage floor before commencing to eat. Card-
board boxes served as shelters and, again in the
interests of sanitation, these boxes were replaced
weekly.
At first the animals were fed a mixture of
crickets, ground meat, egg yolk, canned milk,
49
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pablum, banana and a vitamin supplement
(ABDEC). This mixture was readily taken by
all four but after two months J began to refuse
the preparation and was switched to dead white
mice, which were beheaded and skinned before
being offered.
The animals were found to be quite sensitive
to minor skin irritations. Areas on the flanks and
abdomen were potential loci where prolonged
scratching could produce a local abrasion with
subsequent infection. The tail and soles of the
feet were also subject to minor abrasions which
could become infected. All areas of irritation
responded to treatment with White’s A-D Oint-
ment. It would appear that fresh, damp humus
provides the best substrate for caged animals,
but sanitary requirements necessitated the use
of newspaper as the least abrasive substitute.
Observational Procedures
In order to study the solenodon’s methods of
foraging and its encounter behavior, a 4 X 4 ft.
arena was utilized. This arena had an earth-
covered floor with pieces of bark and logs scat-
tered on the substrate. Observations were made
at night with a dim white light or a ruby bulb.
Encounters were staged by simultaneously plac-
ing two specimens in the arena. Interaction pat-
terns were recorded on a portable tape recorder
and later transcribed on paper. Supplementary
observations and recordings were run in small
rooms measuring 10x15 feet. The vocal reper-
toire of the animals was recorded by a Uher 300
tape recorder coupled to an Electrovoice uni-
directional microphone, with taps speeds of IV2
ips. Recordings from the Uher were analyzed on
a Kay Sonograph. Ultrasonic vocalizations were
studied with a Granath microphone sensitive to
sounds between 5 kc. and 150 kc. Sounds were
transmitted from the microphone to a Precision
Instrument tape recorder 202 that recorded at
60 ips. A Krohn-Hite band pass filter 310AB
eliminated noise beyond and below the Soleno-
don sounds. The sounds were then played back
and photographed on an oscilloscope, using a
Grass instrument 35 mm. oscilloscope camera.
Body temperatures were measured throughout
a 24-hour cycle by an electric telethermometer
(Yellow Springs Instruments). The thermo-
couple was inserted in the anus of the solenodon
to a depth of 2 to 3 centimeters.
III. General Maintenance Behavior3
General Comments on Activity
Solenodon paradoxus appears to be strictly
8Unless otherwise defined, all behavioral terms are
identical with those described in Eisenberg, 1963.
nocturnal. It avoided bright lights and almost all
exploratory activity was confined to the early
evening hours. During the day, the animals
would arouse from time to time and scratch or
defecate but prolonged excursions out of the
nest box were always curtailed in the presence
of bright light.
In the laboratory Solenodon exhibits a slight
diel variation in its body temperature but shows
no tendency to slip into an annual period of
torpor so characteristic of certain tenrecoids
such as Echinops (Herter, 1962a, 1962b). An
adult female Solenodon remained active through-
out more than one year in captivity, including
the summer months when twenty Echinops in
the same room were torpid (room temperature
20-23° C.). Table 1 indicates the contrast be-
tween Solenodon and Echinops with respect to
thermoregulation. The data in this table were
recorded in March and April of 1965 when the
laboratory colony of Echinops was torpid. The
cloacal temperature of Echinops fluctuated with
the ambient temperature, remaining only .6 to
1.6° C. above the environment, whereas the
rectal temperature of a female Solenodon was
maintained at an average level of 6.4° C. above
the ambient.
Locomotion and Rest
On a plane surface during a slow walk the
animals employ a crossed extension limb syn-
chrony but when disturbed a quadrupedal ri-
cochet is exhibited, with the forelimbs and hind-
limbs alternately striking the ground. Solenodons
can run surprisingly fast and if familiar with
their living space they are quite able to move
directly to the nearest shelter. They seem in-
capable of jumping but can climb, using a slow
crossed extension pattern of coordination. When
climbing, they reach up with the forelimbs while
resting on the hind limbs and the stout, muscular
tail.
When alone, a solenodon sleeps on its side,
generally curled in a semicircle. When two ani-
mals sleep together the sleeping postures are
quite variable, and generally one crawls under
the other. The bottom animal usually maintains
a posture on its side but the top animal often lies
prone at right angles to its partner’s body.
Attitudes During Exploration
The behavior patterns during the exploration
of a novel environment are not markedly dif-
ferent from those of other mammals (Eisenberg,
1963; 1964). At first the animal moves slowly,
pausing to assume an elongate posture generally
with one forepaw raised off the ground. Later on
an upright posture may be assumed with both
forefeet off the ground while the head is rotated
1966]
Eisenberg & Gould: Solenodon paradoxus in Captivity
51
Table 1. Comparison of Thermoregulation between Echinops and Solenodon paradoxus*
Specimen
Number
of
Readings
Range of
Ambient
Temperature
C°
Range of
Rectalf
Temperature
C°
Average
Difference
between Rectal
and Ambient
Temperatures
Solenodon
10
24.0-26.8
30.5-33.7
6.4° C.
Echinops
33
21.0-27.3
21.4-28.4
.6° C.
32
21.0-27.3
22.3-31.6
1.6° C.
33
21.0-27.3
21.8-30.2
1.3° C.
*Data were taken at 3- to 4-hour intervals throughout at least one 24-hour period from three adult Echinops
and one adult Solenodon during March and April, 1965.
tCloacal temperatures for Echinops.
to the left or right or bobbed up and down.
Cracks and interfaces are sniffed thoroughly
and the long, flexible snout is inserted in any and
all available niches. After a thorough investiga-
tion of a novel area the animal establishes paths
which are then utilized in a stereotyped fashion.
Attitudes of Defense and Escape
When startled by a sudden motion or disturb-
ance, a solenodon generally flees. If it is in a
familiar area, the flight response is directed to-
ward the nearest shelter. When seized by the
tail, it makes strenuous efforts to pull away, but
it will also turn and attempt to bite. The claws
are extremely sharp and a struggling animal may
inflict deep scratches on the handler. Neverthe-
less, with some dexterity a solenodon can be
caught and held with impunity. A fast-moving,
cat-sized predator should have no difficulty in
dispatching it, and it is not surprising that on
Hispaniola the introduced cat, dog and mon-
goose apparently have been responsible for the
decline in numbers of the solenodon. Prior to
the introduction of these animals, the island was
apparently free from medium-sized or large
predators.
Comfort Movements and Care of the
Body Surface
The yawn, shake and stretch exhibited by Solen-
odon are basic patterns common to all mammals.
In addition, the solenodon may rub its side
against logs or grass and wipe its snout by low-
ering the head and drawing the nose through the
soil. A stereotyped washing sequence involving
the tongue and forepaws is lacking. The tongue
and teeth are occasionally employed to clean the
flanks but the forepaws were never employed in
self-care. Instead, the hind feet are used to
scratch almost the entire body and thus become
the dominant “cleaning organs.” The extremely
flexible hip joint permits a rather complete cov-
erage of the body surface except for the rump
and perineum. Interestingly, hair is entirely lack-
ing on the rump, around the base of the tail and
around the anus. It would appear that this is an
adaptation to the reduced role of the mouth and
forepaws in self-care.
Feeding and Drinking Behavior
The solenodon takes water from a dish and
laps with the tongue in a typical mammalian
fashion. Its demand for water is quite pro-
nounced, with a prolonged intake after arousal
and after feeding. Water intake is undoubtedly
related to the amount of moisture contained in
the food, and in the wild the solenodon’s diet of
invertebrates with a high water-content may per-
mit it to move independently of a permanent
free-water source. When drinking from a dish,
the long snout is in the way and is generally bent
upward in a slight bow. Even so, the nostrils are
often submerged, whereupon the animal exhales
explosively. After a period of lapping, the head
is raised while the water apparently is still being
swallowed. This head-raising was also noted
when the animal was swallowing or chewing
foodstuffs and may be functionally related to
swallowing in that the esophagus is straightened
and held at a constant descending slope. It also
permits the animal to survey its surroundings im-
mediately after being engaged in drinking or
chewing. This could be of adaptive significance
in permitting the detection of predators.
The mode of capturing food varies somewhat
with the type of prey and the circumstances of
foraging. The basic act is quite stereotyped: the
animal moves about with its nose to the ground,
sniffing and poking it into any crack or under
any object. If a prey object (e.g., a cricket) is
contacted with the nose, the animal simultane-
ously extends its forepaws on either side of the
prey while sliding its head forward. As it scrapes
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back with its forepaws, the mouth opens and the
undershot lower jaw is slipped under the cricket,
thus completing the catch. The forepaws are
also used to dig in the earth or tear open logs. In-
sect larvae or centipedes are captured easily since
the narrow lower jaw fits into many of the
natural cracks and larval tunnels of rotten logs.
While foraging, the snout is moved constantly.
The prey is apparently located by tactile and
perhaps by auditory or olfactory stimuli. The
great mobility of the snout permits a consider-
able “search radius” as the animal moves slowly
forward. The long claws and powerful forelimbs
permit both burrowing and the tearing up of
rotten logs. If the substrate is very loose, the
animal will move forward with the tip of the
snout about half an inch to an inch below the
surface of the soil.
The prey-capturing movements are so stereo-
typed that they are often shown even with re-
spect to prepared foods presented in a dish. Fe-
male J was prone to utilize the forepaw reach
and/or digging movements when eating from
a dish. As a result the food would be scattered
all over the floor and each individual piece of
meat would be “captured.” Male M was less
prone to exhibit these movements and often ate
by a combination of lapping with the tongue and
scooping with the lower jaw. The animals are
somewhat at a disadvantage in eating soft food
from a dish or from a plane surface. If the arti-
ficial foods are liquid enough they can be lapped,
but more solid foodstuffs are often “captured”
with stereotyped movements.
Large prey objects such as mice are picked up
in the mouth, chewed and shaken by rapid,
alternate, lateral head movements. While the ani-
mal sits on its hindlegs and holds the prey in its
mouth, the forepaws are used (alternately or
simultaneously) to tear the exposed body dis-
tally. The carcass is thus torn to pieces and each
piece is picked up and eaten in turn. The jaw
movements are vertical with no apparent side-to-
side chewing motion, but at any given time only
one side of the jaw is employed during the
shearing action of the molars.
Although pieces of food are picked up and
carried, the animals never cached food in the
den nor did they bury food in any special place
(see also Mohr, 1938).
Elimination and Marking
Urination and defecation are generally per-
formed together after the animal has aroused
and left the nest. During defecation the tail is
bent slightly upwards while the animals rests on
all fours in a slightly-hunched posture. As the
animal moves away from the newly deposited
feces it may depress its anal region and drag it
on the substrate. There is no kicking back move-
ment or attempt to cover the feces. In captivity
defecation and urination appeared to occur ran-
domly in the cage, with one exception. If the
animals defecated during the day they used one
spot immediately adjacent to the nest entrance.
The inhibiting effect of light appeared to prevent
a longer excursion.
Marking is generally defined as a behavior
pattern serving to deposit some chemical sub-
stance employed in olfactory communication.
Feces and urine are potential substances for
chemical communication but, as explained pre-
viously, they are not localized except at the en-
trance to the nest box. The animals have pro-
nounced glandular areas on the ventrum, axilla
and flanks (Mohr, 1937), but aside from the
occasional side rub described under “Comfort
Movements” there were no stereotyped marking
movements. Perhaps glandular secretions are
left behind in the course of the animal’s foraging
activity, or again the depressing and dragging of
the anal region after defecation may serve to
spread exudates from the anal glands, but novel
marking movements were not observed in this
study.
Construction of Artifacts
As reported by Mohr ( 1938), Solenodon digs
tunnels and may live in small family groups
within the same burrow system. It is doubtful
whether nesting material is carried to the bur-
row; no transport of nesting material by juveniles
or by non-breeding adults was observed in cap-
tivity. A parturient female may, however, build
a nest and is quite capable of transporting mate-
rials in her mouth. Each day during July, a
solitary female that had nursed a young eight
months earlier, constructed a nest of shredded
newspapers sometime after the daily cleaning of
her cage. Earlier in the spring we observed no
nest building; therefore, the behavior may be
related to sexual activity.
IV. Patterns of Social Behavior
Communication
Classically, the forms of animal communica-
tion are as variable as the sense organs capable
of receiving the potential signals. In Solenodon
the small eyes and nocturnal habits preclude
vision as a dominant communication channel
and leave us with a consideration of the chem-
ical, tactile and auditory senses. The forms of
tactile communication will be discussed under
encounter behavior. The chemical aspects of
communication were not studied but judging
from the ubiquitous gland fields on the body it
is of no small importance. As for the auditory
1966]
Eisetiberg & Gould: Solenodon paradoxus in Captivity
53
Table 2. Physical Description of Solenodon Vocalizations
l.Soft Squeak
Eleven recordings from two individuals were measured.
Greatest energy: 2,100 cps. to 3,600 cps. or 1,800 cps. to 2,300 cps.
Harmonics are present at 4,800 to 6,300 cps. or 3,300 to 4,100 cps.
Duration of sounds ranged from .03 to .13 sec.
Interval between sounds in a series ranged from .17 to .80 sec.
2. Twitter
Two series from one individual.
Greatest energy: 1,700-2,200 cps.
Harmonics are present at 2,800 and 3,300 cps.
Duration of sound series is about .13 sec. while each component averages 25
msec, with a separating interval of 5 msec.
3. Chirp
Four recordings from one individual.
Greatest energy: 2,500-3,400 cps.
Harmonics blurred but energy distribution ranges from 1,400 to 12,000 cps.
Duration: .1 to .2 sec.
4. Click
Energy concentrated at 9,900 to 31,000 cps. Average of 11 pulses: 16,000 cps.
Duration: 0.1 to 3.6 msec. Average of 9 pulses: 0.8 msec.
Delivered in bursts with numbers of sounds varying from 1 to 6 within a given
burst.
aspects of communication, a list of sounds fol-
lows, with a discussion of their potential com-
municatory significance (Table 2 and Plates I &
II). Although no experiments were done to
verify the signal value of these sounds, the vocali-
zations show remarkable similarities to those of
soricoids.
1. Chewing. — The vertical jaw movements
generally produce an audible smacking or
crunching sound. These chewing sounds often
attract the cage mate.
2. Digging Sounds.— The usual shuffling sound
of forepaw movements and kicking back often
serve to attract the cage mate.
3. Sounds Accompanying Walking or Run-
ning.— The sounds accompanying rapid move-
ment often induce movement and following in
a young animal.
It appears that the animals learn to associate
sounds of digging or chewing with food and
these sounds promote aggregation and social
cohesion. This was especially true of the J and
M relationship. The young male (M) was quite
prone to remain in contact with J, and again the
sounds of her movements served to direct and
coordinate his movements.
4. “Puff.” — This sound is a sharp exhalation
which seems to function in the clearing of nasal
passages.
5. “Piff.” — This explosive sound is a variant of
“Puff.”
6. Cough. — This sound accompanies sudden
explosive exhalations through the throat.
Vocalizations
1. Twitter.- — -This is a sound of uncertain sig-
nificance. It is generally heard when a specimen
is excited at feeding time, when an animal is
picked up or during contact-promoting behavior.
It appears to be a repetitive version of vocaliza-
tion 3, below.
2. Chirp. — This is a single, forceful note given
when an animal is in an upright defensive pos-
ture.
3. Soft Squeak. — -This sound is repeated in
bursts of two or three notes during contact be-
tween two familiar animals which have been
separated.
4. Squeal.- — This long, high-pitched sound ac-
companies a fight.
5. Click. — This is a sharp, high-pitched sound
produced during exploration of a novel area or
when initially encountering a strange animal.
This vocalization is similar to the echolocation
pulses of shrews (Gould, 1964). In common
with shrew pulses, there is no frequency modu-
lation.
Interaction During an Encounter
An encounter between two solenodons strange
to each other is marked by several interesting
features. One or both animals approach with
head raised, mouth half-open, and nose twitch-
ing. Puffs and piffs are clearly audible but these
sounds may be concomitants of clearing the
nostrils and have no direct communicatory func-
tion. Ultrasonic clicks are produced and, in
addition to their presumed communicatory
significance, these sounds may serve to localize
the partner. The slow approach with heads
raised continues until the vibrissae touch. The
noses may then touch, whereupon several varia-
tions can occur. (1 ) It is not uncommon for one
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Zoologica: New York Zoological Society
[51: 4
animal to seize the snout of the second in its
mouth. The snout is gently held for a few sec-
onds and then released. (2) Contact is also
maintained by pushing the nose tip into the ear
of the partner. ( 3 ) Asa variant, the animals may
stand parallel to one another while one (or
both) pushes the nose into the axilla, groin or
flank or presses the snout on top of the rump.
These three patterns of initial contact serve to
keep the position of the mouth “neutralized”
and allow the glandular areas to be sniffed.
A similar pattern is present in two genera of
tenrecs, Centetes and Microgale, and appears to
serve the same function. However, the jaws
merely enclose the snout of another tenrec and
were never seen to clamp on it. This distinctive
behavior pattern of Solenodon, Centetes and
Microgale is obviously another variation of
mouth-to-mouth contact which is discussed in a
phylogenetic sense by Tembrock (1964).
Contact between solenodons may be rein-
forced by licking on the rump or back and in
addition one animal may place its forepaws on
the back of the partner while it presses the nose
firmly against the rump or presses across the
back and on the flank of the opposite side of the
partner.
Agonistic behavior may develop out of an
encounter and generally involves “rumping” or
pushing suddenly with the hidequarters against
the body of the partner. A partner may also be
pushed by a sudden jab with the snout. Active
aggression may be manifested by slapping with
a forepaw, kicking with the hindfeet or deliver-
ing a slashing bite by moving the head from side
to side while snapping the jaws. Occasionally,
both animals may rise upright on their hindlegs
and, while keeping their balance, push against
one another with their forepaws. This stance
may include grasping the partner with the fore-
paws, and if one animal is toppled both may
roll together on the ground before separating.
A defeated animal will generally avoid the
second by moving away or fleeing. An aggres-
sively aroused animal has been observed to chase
a second animal, but no sustained aggressive be-
havior was noted. None of the agonistic interac-
tions is unique but all are variations on common
mammalian behavior patterns (Eisenberg, 1962;
1963; 1964).
Interaction Patterns among Cage Mates
The two adult females (A and B) as well as
the young pair (J and M) were kept as two sep-
arate social units. The cagemates slept together
and exhibited little agonistic behavior except at
feeding. At feeding time, rumping, wrestling,
rushing and moving away were commonly ex-
hibited between J and M. J was dominant until
M reached about six months of age, whereupon
a definite dominance reversal occurred and M
was allowed first position at the feeding dish.
Gradually the rivalry at the food dish declined
since M was not as prone to attack as J had been
in the previous months.
The adult females slept in contact but gen-
erally avoided play or intimate contact when
they were foraging in the cage. The two juveniles
were quite active and indulged in frequent con-
tact, which included nose to nose, nose to body
(the body loci included those previously dis-
cussed), rubbing one side of the body against
the partner, following and wrestling. Wrestling
was a slow version of the upright and rolling
fight described previously and it never ended in
a chase or in bloodshed. Occasionally one ani-
mal would slide its head under the chin of the
partner exhibiting a head over— head under con-
figuration. Very infrequently one animal would
lick the other on the back or rump. (See also
Mohr, 1936 I).
V. Ontogenetic Aspects of Behavior
Since M was judged to be about four months
of age at the beginning of the study, we possessed
a unique opportunity to study the changing be-
havior of M and his relation to J as he matured.
M possessed a marked tendency to follow J and
learned to eat at least one food item by associa-
tion with J at feeding time; however, at the time
of his dominance assertion (two months later)
he was no longer prone to follow J in an open
field-testing situation.
Although the following response was very
strongly developed in M, J was also prone to
follow and, on occasion, would move behind
M if he initiated a sustained movement. M not
only followed, but he also attempted to contact
J whenever she stopped. He would rest his nose
on her rump or nape and occasionally attempted
to climb on her or under her (see also Mohr,
1936 I; 1937). Initially, he preferred to eat from
the same dish as J and this led to a certain
amount of antagonism from J; however, he per-
sisted and was generally on hand whenever she
fed.
J was adept at catching crickets from the be-
ginning, but M did not attempt to catch or eat
them. The animals were tested alone with crick-
ets for five days and J always captured and fed
while M would sniff and occasionally capture
with his forepaws but did not feed. On the sixth
night they were fed together. Since M always
followed J and attempted to feed with her, he
was exposed to the crickets and actually licked
her mouth while she was chewing. This associa-
1966]
Eisenberg & Gould: Solenodon paradoxus in Captivity
55
tion was sufficient to induce him to bite the next
cricket and, after dropping it, to pick it up and
eat it. Thereafter M caught and ate crickets
which were presented to him. It is interesting to
note that the young of Echinops telfairi have also
been observed to lick the mother’s mouth when
she is feeding. The usual avoidance movements
are not initially shown by the mother to her very
young offspring and it would appear that par-
ental food preferences can be transmitted to the
young in this fashion. Of course, if this learning
is to occur the young must be with the female as
she forages, hence there must be a strong follow-
ing tendency on the part of the juvenile and a
further tendency to seek out and maintain physi-
cal contact with the mother when she feeds. It
seems probable in the case of our solenodons
that M treated J as a parental object and was
exhibiting behavior patterns typical of a juvenile-
adult situation.
In summary it would appear that the young
mammal develops associations among the vari-
ous stimuli such as parental odor, tactile input,
warmth and nourishment. As the juvenile ma-
tures it seeks to follow the parent and maintain
on olfactory and tactile input. The sounds of the
parent as it moves and forages become synchron-
izing and directional signals to which the juvenile
responds. Chewing sounds become associated
with feeding and mouth to mouth contact helps
to establish food preferences. The parent can
serve to direct food preferences as well as the
choice feeding loci. Specialized insectivores such
as Solenodon may derive a special benefit from
a prolonged association with the family group,
since feeding loci and food selection could thus
be insured in each generation. This may account
for the small family groups of Solenodon that
are frequently caught in the same tunnel (Mohr,
1937).
VI. Some Comparisons of Solenodon with
Other Insectivora
One of our objectives was to determine wheth-
er Solenodon shared behavioral traits with the
Soricidae which might bear on its taxonomic
status. Shrews of the genus Sorex and Blarina
emit pulses which serve as a crude means of
echolocation (Gould, 1964). The Tenrecidae
also echolocate (Gould, 1965); Echinops, Hemi-
centetes, Microgale and probably Centetes util-
ize tongue clicks rather than pure tones as in
shrews. Clicks of the tenrecs range between 5
kcs. and 17 kcs. Shrews produce ultrasonic puls-
es ranging from 25 kcs. to 60 kcs., the sounds
probably originating from the larynx. The clicks
of Solenodon resemble the echolocating pulses
of Sorex more than they resemble pulses of ten-
recs. High frequency clicks of both Sorex and
Solenodon are composed of pure tones in con-
trast to the clicks of tenrecs that drop in fre-
quency at the end. Andrew ( 1 964) has discussed
the resemblance of vocalization in Sorex and
Tupaia with respect to three general types of
sounds. The twitter, chirp and soft squeak of
Solenodon probably fit into Andrew’s classifica-
tion and a thorough analysis of tenrec vocaliza-
tions will probably fit into Andrew’s general
scheme.
When we turn to other behavior patterns the
picture is less clear. All of the present day in-
sectivores are quite specialized. Although the
order Insectivora is primitive in some morpho-
logical features, its members have diversified to
fill a variety of niches and, as a consequence,
have evolved profound differences in behavior.
In many respects Solenodon has a simplified
behavioral repertoire. Its main specializations
apparently concern an adaptation to foraging in
soft litter and rotten logs. We find a long, flexible
snout; under-shot lower jaw; enlarged forepaws
bearing long claws; powerful forelimbs; noc-
turnal habits; a reduced litter size with a pro-
longed juvenile development; a tendency for the
young to follow the parent, and the formation
of small family groups. Solenodon does not ap-
pear to cache food and it is doubtful that it
aestivates. The specializations of its snout and
forelimbs appear to have prevented the reten-
tion of or evolution of complex self-care pat-
terns involving the forepaws and tongue. The
hindfoot has remained the dominant cleaning
organ and selection has favored the loss of hair
on the rump and around the anus.
Sorex vagrans is specialized for foraging in
leaf litter by being very reduced in size. Like
Solenodon, the hindfoot is the dominant clean-
ing organ. Unlike Solenodon, it has not lost its
hair around the perineum and rump, but uses
its tongue in self-care and together with its sub-
terranean activity is able to maintain its pelt
free of foreign matter. Sorex is further special-
ized by having a pronounced tendency to cache
food (Eisenberg, 1964).
The menotyphlan Tupaidae are very divergent
morphologically, having specialized for diurnal-
ity and having evolved complex marking patterns
involving a special chest gland. In T upaia glis the
forepaws and mouth are dominant cleaning or-
gans (Kaufman, 1965). However, the specializa-
tions in marking and body care typified by Tu-
paia should not be thought of as necessarily ad-
vanced. Complex marking and cleaning move-
ments are exhibited by many species of the Ten-
recidae and Erinaceidae.
Erinaceus europaeus, the hedgehog, does not
56
Zoologica: New York Zoological Society
[51: 4
exhibit cleaning movements with its forepaws
but it does have a complex, stereotyped marking
pattern termed “self-anointing” or Selbstbe-
spucken. Essentially this pattern consists of lick-
ing a foreign substance (e.g., urine, feces, etc.)
while accumulating a mass of saliva in its mouth.
This saliva is then spread on the sides of the body
with the tongue (see Herter, 1957; Eisentraut,
1953). No other insectivore appears to show
this response except the arboreal tenrec, Echi-
nops telfairi, which has evolved a similar pat-
tern. Echinops will sniff and lick urine of another
tenrec and then wipe a forepaw in the urine.
Resting on three legs Echinops will reach back
with its forepaw and spread the mixture of urine
and saliva on its side. It does the same after rub-
bing its forefeet in sand or on the waxy surface
of certain Euphorbia plants. As with the true
hedgehog, the process is stereotyped and repe-
titive. In addition it should be noted that in con-
trast to Erinaceus, Echinops has a complex,
stereotyped washing pattern involving the fore-
limbs in which it sits hunched on its hindlegs
while alternately wiping its muzzle with its fore-
paws (see Herter, 1963a).
Outside the breeding season Solenodon gen-
erally does not build a nest. In this respect adult
Centetes, Erinaceus and Echinops are similar.
However, Erinaceus will build a leaf nest at the
time of hibernation and young Centetes build a
nest when the room temperature drops. On the
other hand, several genera of shrews, including
Sorex and the tenrec, Hemicentetes , habitually
build nests regardless of the season and their
reproductive state.
Finally it should be mentioned that Centetes
ecaudatus, although lacking complex cleaning
movements with the forepaws, has a specialized
comfort movement at the time of defecation.
The animal invariably digs a hole with its fore-
paws, deposits the feces in the hole, and then
covers the feces by a combination of backward
thrusts with the forepaws and the hindfeet.
We wish to reiterate that although the be-
havior patterns of Solenodon are simplified they
do not necessarily reflect a behavioral simplicity
common to morphologically primitive mammals.
In our brief review we have indicated the exist-
ence of rather complicated marking and com-
fort movements in the primitive Erinaceidae and
Tenrecidae as well as in the advanced Tupaidae.
It may well be that the lack of behavioral com-
plexity is a primitive trait in Solenodon but it is
equally probable that Solenodon represents an
endpoint in specialization for a certain type of
foraging efficiency and exhibits a reduction with
respect to certain forms of behavioral complex-
ity.
Summary
Observations on captive solenodons were un-
dertaken in 1962 and 1964 but during the win-
ter and spring of 1965 two adult and two juvenile
specimens of Solenodon paradoxus were studied
intensively for three months. A series of stand-
ard tests were run in order to study their main-
tenance and social behavior. With the exception
of mating behavior and early parental care, the
behavior patterns of Solenodon paradoxus were
described in detail. Solenodon exhibits a rather
specialized set of foraging patterns with an over-
all simplification of its behavioral repertoire.
Its vocalization patterns resemble those of the
Soricidae and Tupaiadae. Solenodon produces
high-pitched vocal pulses similar to the echolo-
cating sounds employed by Sorex.
The simplified behaviorakrepertoire of Soleno-
don may well be the result of specialization rath-
er than representative of a primitive mammalian
condition.
Acknowledgments
The advice and cooperation of Mr. Joseph
A. Davis, Curator of Mammals at the New York
Zoological Park, are deeply appreciated.
Initial studies of sound recordings of Soleno-
don were conducted when Gould worked under
the direction of Dr. Alvin Novick of Yale Uni-
versity.
References
Andrew, R. J.
1964. The displays of the primates. In: Evolu-
tionary and genetic biology of primates
(John Buettner-Janusch, Ed.). Academic
Press, N. Y„ 2: 227-309.
Eisenberg, J. F.
1962. Studies on the behavior of Peromyscus
maniculatus gambelii and P. californicus
parasiticus. Behavior, 19: 177-207.
1963. The behavior of heteromyid rodents. Univ.
Calif. Publ. Zool., 69: 1-100.
1964. Studies on the behavior of Sorex vagrans.
Am. Midi. Nat., 72: 417-425.
Eisentraut, M. C.
1953. Sichbespucken bei Igeln. Zeit. f. Tierpsy-
chol., 10: 50-55.
Gould, E.
1964. Evidence for echolocation in shrews. J.
Exp. Zool., 156 (1): 19-38.
1965. Evidence for echolocation in the Tenreci-
dae of Madagascar. Proc. Amer. Phil. Soc.
(In press).
Herter, K.
1957. Das Verhalten der Insektivoren. Handb.
d. Zool. VIII, Lieferung, 9: 1-50.
1966]
Eisenberg & Gould: Solenodon paradoxus in Captivity
57
1962a. Uber die Borstenigel von Madagaskar
(Tenrecinae). Sitzgsber. Ges. Naturf.
Freunde Berlin, N. F. 2: 5-37.
1962b. Untersuchungen an lebenden Borstenigeln
(Tenrecinae). I. Uber Temperaturregulie-
rung und Aktivitatsrhythmik bei dem Igel-
tanrek Echinops telfairi Martin. Zool.
Beitrage, N. F., 7: 239-292.
1963. Untersuchungen an lebenden Borstenigeln
(Tenrecinae). II. Uber das Verhalten und
die Lebensweise des Igeltanreks Echinops
telfairi Martin in Gefangenschaft. Zool.
Beitrage, N. F., 8: 125-165.
Kaufmann, J. H.
1965. Studies on the behavior of captive tree
shrews (Tupaia glis). Folia Primat., 3: 50-
74.
McDowell, S. B.
1958. The greater Antillean insectivores. Bull.
Amer. Mus. Natur. Hist., 115: 115-214.
Mohr, E.
1936-38. Biologische Beobachtungen an Solen-
odon paradoxus in Gefangenschaft (Parts
I-IV). Zool. Anzeieer, 113: 177-188; 116:
65-76; 117: 233-241; 122: 132-143.
Tembrock, G.
1964. Vergleichende Verhaltensforschung bei
Saugetieren. Zool. Gart., N. F., 29: 241-
261.
58
Zoologica: New York Zoological Society
[51: 4
EXPLANATION OF THE PLATES
Plate I
Fig. 1. Sonographs of Solenodon vocalizations.
The ordinate displays the sound frequency
while the abcissa is scaled in milliseconds.
A. A single chirp. Note the broad energy
distribution at the onset and termination.
B. A twitter. Note the harmonics. C. A
single soft squeak. Note the single har-
monic.
Plate II
Figs. 2 & 3. Oscilloscope traces of sound pulses emit-
ted by Solenodon as it searched an un-
familiar place. Sweep speed: 5 msec., un-
expanded. The oscilloscope trace moved
from left to right and bottom to top. The
band pass filter was set at 5 kcps. low pass
and 100 kcps. high pass.
Fig. 2. Duration about 1.1 msec.; Frequency
about 21 kcps.
Fig. 3. Duration about 0.6 msec.; Frequency
about 11 kcps.
KILOCYCLES
EISENBERG a GOULD
PLATE 1
7
A
B
C
200 400 600 800 1000
MILLISECONDS
FIG. 1
THE BEHAVIOR OF SOLENODON PARADOXUS IN CAPTIVITY WITH
COMMENTS ON THE BEHAVIOR OF OTHER INSECTIVORA
EISENBERG & GOULD
PLATE II
FIG. 2
FIG. 3
THE BEHAVIOR OF SOLENODON PARADOXUS IN CAPTIVITY WITH
COMMENTS ON THE BEHAVIOR OF OTHER INSECTIVORA
ZOOLOGICA
SCIENTIFIC CONTRIBUTIONS OF THE
NEW YORK ZOOLOGICAL SOCIETY
VOLUME 51 • ISSUE 2 • SUMMER, 1966
PUBLISHED BY THE SOCIETY
The ZOOLOGICAL PARK, New York
Contents
PAGE
5. The Capture and Care of a Killer Whale, Orcinus orca, in British Columbia.
By Murray A. Newman & Patrick L. McGeer. Plates I- VIII; Text-
figures 1 & 2 59
6. Sound Structure and Directionality in Orcinus (killer whale) . By William
E. Schevill & William A. Watkins. Figures 1-5 71
7. Effects of Vitamin Antimetabolites on Lebistes reticulatus. By George S.
Pappas. Text-figures 1 & 2 77
Zoologica is published quarterly by the New York Zoological Society at the New York
Zoological Park, Bronx Park, Bronx, N. Y. 10460, and manuscripts, subscriptions, orders for back
issues and changes of address should be sent to that address. Subscription rates: $6.00 per year;
single numbers, $1.50, unless otherwise stated in the Society’s catalog of publications. Second-class
postage paid at Bronx, N. Y.
Published September 15, 1966
5
The Capture and Care of a Killer Whale, Orcinus orcci,
in British Columbia
Murray A. Newman
Vancouver Public Aquarium
Stanley Park, Vancouver, B. C.
Patrick L. McGeer
Kinsmen Laboratory of Neurological Research
University of British Columbia
Vancouver, B. C.
(Plates I-VIII; Text-figures 1 & 2)
Introduction
A lthough a dozen or more species of small
L\ cetaceans have been captured and main-
X Attained alive for varying lengths of time,
only one capture of a killer whale (Orcinus orca)
is recorded in the literature (Caldwell & Brown,
1964) . That specimen was evidently ill and lived
only 18 hours after being caught in a large net
off Southern California.
The attempted capture of an adult female by
Marineland of the Pacific collectors in northern
Washington in September, 1962, resulted in the
animal tangling the line around the propeller
and attacking the boat (personal communication
from Frank Brocato) . Fearing that the boat
would be damaged, the collectors killed the ani-
mal.
Killer whales are most abundant in the waters
of British Columbia in late spring, summer and
early fall (Table 1 ) , while in Southern California
they are most often observed in fall, winter and
early spring (Norris & Prescott, 1961). This
may possibly indicate a seasonal migration, but
some individuals remain in the north during the
winter and they have been recorded in Puget
Sound at all seasons (Scheffer & Slipp, 1948).
They are particularly common during the
summer in the Strait of Georgia and Johnstone
Straits, where they often gather in large numbers
in association with the migrations of salmon and
herring. The whales are frequently seen near
the mouths of the Fraser and Campbell Rivers
in summer by both commercial and sports fisher-
men. While they are the best known and most
abundant species of whale in these inland waters,
they may swim far offshore, where they are oc-
casionally seen by the crew of the Department
of Transport weather station “Papa” at 50°N
Latitude, 145°W Longitude, approximately 970
km. west of Vancouver Island (Pike & Giovando,
1963).
History
East Point, Saturna Island, is a narrow penin-
sula of land with steep, sandstone cliffs that
drop off into many fathoms within a few meters
of the shore.
Vancouver Public Aquarium collectors
mounted a harpoon gun there on May 20th,
1964, with the intention of killing a specimen
as a basis for the preparation of a replica for
the Aquarium’s new British Columbia Hall.
Eight pods of Orcinus, totalling about 60
whales, were observed during the 57 days of
waiting. All came from the direction of the
Strait of Juan de Fuca and the open ocean.
Dates of sighting were May 22, 24, 26, 28, June
25, July 2 and July 16. Almost a month passed
between May 28 and June 25 without a sighting.
The collecting crew harpooned a young male
orca on July 16 (Fig. 1). A harpoon 117 cm.
long and 5 cm. in diameter, with 36 cm. spread
flukes and weighing 6.8 kg., was fired from the
shore. The whale was struck as it was swimming
parallel to the cliffs, about 20 meters from land.
59
60 Zoologica: New York Zoological Society [51: 5
Table 1
Killer Whales Seen from East Point Lighthouse
Saturna Island
1958-1963*
Month
Total
Seen
Average Number
Remarks
Jan. -Feb.
64
Av. for 3
yrs— 0.4/day
Seen infrequently, none in 1961 and 1962.
March
38
Av. for 3
yrs— 0.4/day
Seen infrequently, none in 1961 and 1962.
April
52
Av. for 5
yrs— 0.4/day
Seen infrequently, mostly going north.
May
332
Av. for 5
yrs— 2.2/day
Increasing; going north and south. Many
young.
June
466
Av. for 5
yrs— 3.0/day
Increasing. More going south.
July
463
Av. for 5
yrs— 3.0/day
As for June.
August
631
Av. for 6
yrs— 3.4/day
Peak month. Larger groups. Mostly going
north.
Sept.
344
Av. for 4
yrs— 2.9/day
Decreasing. Mostly going north. None re-
ported in 1959.
Oct.
220
Av. for 4
yrs— 1.8/day
Decreasing.
Nov. -Dec.
—
—
None.
*Compiled by Mrs. Peter Fletcher and made available by Ian MacAskie of the Fisheries Research Board,
Nanaimo, B.C.
The harpoon entered the left side of the body,
just posterior to the calvarium and dorsal to the
vertebral column, and passed completely through
(Fig. 2).
The whale appeared to be stunned by the shot.
Two other whales assisted it to the surface for
the first two or three minutes. The animal slowly
recovered and began swimming and breathing
normally. It headed toward the remaining whales
in the pod, numbering about 12, which held
their position at the surface some distance away.
A 12-meter fishing boat, which had been waiting
nearby, then retrieved the floats on the end of
the 203-meter harpoon line, and the wounded
whale struggled vigorously for a few moments.
Soon afterwards it ceased to struggle, seeking
instead to avoid the boat.
The whale was towed into shore and tied
briefly to a mooring while an attempt was made
to assess its injury. Spectators soon descended
on the scene in boats frightening the whale,
which swam into a bed of kelp. At this point it
became extremely distressed and uttered shrill
whistles so intense that they could easily be
heard above the surface of the water 100 meters
away. The animal was quickly towed out to
deeper water in the channel, and it was then de-
cided to tow it to drydock in North Vancouver,
80 kilometers away, where more detailed ob-
servations could be made. This trip took 16
hours.
The whale was pulled into the dock by the
line held to a stage suspended over the dock from
a movable crane (Fig. 3). Upon entering the
drydock, the animal commenced swimming in
slow counterclockwise circles, a pattern it con-
tinued to follow throughout its life in captivity.
The whale manifested no apparent distress
either from the wound or the voyage, and plans
were initiated to maintain it in captivity.
The rope was removed the next day and the
whale given 30 million units of S.R. penicillin as
a prophylactic measure against wound infection.
This was injected just anterior to the dorsal fin
through a 100 mm. #15 needle.
Six days after capture, the animal was given
another 15 million units of S.R. penicillin with
a syringe mounted at the end of a 2.5 m. pole
(Fig. 4). One gram of thiamine was injected by
a “capture gun” into the mid-dorsal region.
A semi-permanent pen, 14 m. x 23 m., was
constructed inside an abandoned pier at the
Canadian Army Base, Jericho, in Vancouver’s
outer harbor. The pilings were torn from the
middle of the pier and the sides lined with chain
link wire fencing. The location was not far from
the mouth of the Fraser River, where the water
conditions vary considerably. The water at times
was fairly clear, with a surface saline content
of 23 per thousand. At other times it became ex-
tremely muddy, and the saline content dropped
as low as 12 to 15 per thousand. Depth of water
within the pen varied with the tide from 3 to 6 m.
at the shallow end and 4 to 7 m. at the deep end.
The drydock was towed to the new location
1966]
Newman & McGeer: Capture and Care uf Kilter Whale
61
on July 24, 1964, and the whale transferred. Al-
though the whale had not eaten, it appeared to
be in good health with the harpoon wound heal-
ing.
The whale continued to reject all offerings of
food and held its distance from people on the
dock. It never demonstrated aggressive tenden-
cies of any kind. For a brief period, the whale
was studied by an observer on a small raft. It
could easily have overturned the raft but never
more than brushed against it.
On August 6, 1964, the whale was netted and
restrained at one end of the pool. The wound
was inspected and found to be healing well. A
blood sample was taken. The animal was injected
with 30 million units of S.R. penicillin, one gram
of thiamine, 1.5 mg. of vitamin B12 and one
gram of Hydroxyzine hydrochloride (atarax)
just anterior to the dorsal fin.
During the last week of August, lesions began
to appear on the skin (Fig. 5). These lesions,
caused by a fungus, progressed relentlessly until
the animal died.
On September 9, the whale was first observed
to devour a fish suspended on a line into the pen.
The same day it ate 90 kg. of lingcod similarly
suspended. The next day, it was fed fish sus-
pended from the raft inside the pen and there-
after was fed by hand (Fig. 6).
On October 9, 1964, it took three fish but re-
fused to rise out of the water at all to obtain
them. After swimming listlessly for a few min-
utes, it gave an abortive blow while partly under-
water and then sank out of sight.
The whale was lifted out of the water two and
one-half hours later and an autopsy commenced.
During the last two days of its life, the saline
content of the pen reached the lowest recorded
level, 12 per thousand.
Sounds
Extensive recordings were made of the sounds
of the captive whale using a barium titanate
hydrophone.
In common with porpoises and dolphins, the
killer whale emitted two distinct classes of
sounds. The first class consisted of whistles and
squeaks, which were presumably for communi-
cation. The second class consisted of clicks, evi-
dently for the purpose of echo location.
The whistles were varied in nature. The
“whee-ooo-eee” sound most frequently heard is
shown sonographically in Fig. 7. This sound was
heard in a wide variety of behavioral situations.
It was heard during the approach for food, when
it was being netted, when it was being transferred
to its new pen and when it was swimming around
in the absence of any disturbances. Some sounds
were clearly coordinated with the expiration of
air from the blowhole as (Wood, 1953) described
in both Tursiops and Stenella, although this was
the exception rather than the rule.
A typical train of navigational clicks is shown
in Fig. 8. These clicks were occasionally blended
with whistles, but the two types of noise were
never emitted simultaneously as has been re-
ported for Tursiops truncatus (Lilly & Miller,
1961 ). The upper limit of the hydrophone was
15,000 cps. No sounds seemed to be near this
upper cut-off frequency.
On many occasions, the whale collided with
lines suspending fish in the pen. This happened
both in the dark and under conditions of good
visibility. The large size of the animal retarded
maneuverability within the pen and it apparently
had difficulty in avoiding suspended lines. The
degree of echo locating accuracy attributed to
Tursiops by Kellogg (1961) was never deter-
mined for Orcinus and the despondence of the
animal during its period of starvation and isola-
tion may have affected this ability. Orcas must
nonetheless possess considerable ability at echo
locating as they are known to be skillful in avoid-
ing fishermen’s nets.
Feeding Behavior
The whale was offered food from the first
day in captivity, but it is unlikely that very much,
if any, was consumed prior to the 54th day.
Live and dead fish, horse heart, live and dead
poultry, live and dead octopus, squid, whale
tongue, whale meat and blubber, and live and
dead seals were offered at various times.
From the first day of known feeding, con-
sumption went to 45 to 90 kg. per day. A few
fish each day were stuffed with vitamin pills
and minerals. Once feeding began, it showed
marked preferences. The main food accepted
by the whale was soft-rayed fishes such as salmon
(Oncorhynchus spp.), lingcod (Ophiodon elong-
atus) and Pacific cod (Gadus macrocephalus).
Some rough, spiny rockfishes (Sebastodes spp.)
were accepted, but many were rejected. Ratfish
(Hydrolagus colliei) were accepted after removal
of their sharp dorsal spines, but dogfish sharks
(Squalus suckleyi) were rejected even after re-
moval of the spines. Lingcod and Pacific cod
were preferred to squid and horse heart, but
both of the latter were taken in limited amounts.
The whale used its teeth merely for grasping
the fish and never for chewing. In most cases,
it would swallow the fish immediately, head first,
although occasionally it would swim for a time
with the fish held crosswise in its mouth before
rotating it with the tongue and swallowing it.
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Text-fig. 1. Duration of submergence (apnea) in captive Orcinus orca on August 12, 1964, before it
began feeding.
At feeding time, the whale would usually
swim in tight circles, about 10 meters in dia-
meter, near the raft from which it was fed. At
some distance away, it could usually be sum-
moned by slapping the water with a fish. It
swam slowly to the corner of the raft to ac-
cept the fish and would rise partly out of the
water to reach food held two or three feet
above the surface. It always took the food in a
slow and deliberate manner.
The feeder became very confident of the
whale’s harmlessness, occasionally patting it on
the head as it approached for food, and, by slow-
ly rotating the fish over the whale’s head, causing
the animal to turn over on its back. Tursiops
and lnia also swim upside down occasionally
and probably other cetaceans do it, too (Layne
& Caldwell, 1964).
General Behavior
The most astonishing aspect of the behavior
was the complete lack of ferocity or aggressive-
ness. At no time did it make any hostile moves
towards any human involved in the capture,
treatment, netting or feeding operations.
Until the captive whale began feeding, its ac-
tions were extremely difficult to observe be-
cause it was only visible a few seconds at the
surface before it disappeared a minute or more
in the cloudy water (Text-fig. 1). The longest
recorded period of submergence was 3 minutes,
36 seconds. After the whale began feeding on
September 9, it tended to make shorter dives
(Text-fig. 2).
It moved at a constant rate of speed (2 or 3
knots) in a counterclockwise direction without
ever apparently resting. While in the drydock,
it was observed by many people throughout the
day and was not seen to vary from its pattern
of swimming in circles. When is was transferred
to its new pen, guards were posted 24 hours a
day to protect the whale from the public. These
guards also never observed any cessation of
movement. In contrast to this, the whales in
Johnstone Strait were seen occasionally resting
at the surface for brief periods.
It is strongly suspected from this that killer
whales do not experience deep sleep but the
low salinity and concomitant low buoyancy at
the enclosure may have necessitated constant
movement and prevented resting at the surface.
The behavior of the captive animal under-
went a considerable development as it recovered
from its injuries and adjusted to captivity, al-
though it went into a decline just before it died.
During August, it was seen slapping its flukes
and flippers on the surface of the water and
occasionally leaping. After it began feeding.
1966]
Newman & McGeer: Capture and Care of Killer Whale
63
Text-fig. 2. Duration of submergence (apnea) in captive Orcinus orca after initiation of feeding on
three separate days.
this behavior was seen more often. It quickly
learned where to obtain a fish and became re-
sponsive to its feeder. It became tame in the
sense that it grew less wary and afraid of man
and at no time gave any indication of aggres-
sive tendencies.
Lob-tailing and flipper-slapping frequently
took place during a feeding period if an insuffi-
cient amount of food was presented to the whale
or if for some reason there was a delay in the
middle of the feeding. These behavior patterns
seemed to indicate annoyance.
Jumping was observed on three occasions
between 10:00 a.m. and noon in association with
feeding (Fig. 9). On each occasion the animal
jumped almost clear out of the water several
times. It was also seen to jump early in the
morning (4:30—7:00 a.m.) by the guards on
various occasions.
Compared with Tursiops, the captive Orcinus
was large and clumsy, with poor maneuver-
ability and little facial expression. Ability to flex
its head was very limited, although it could
“bend its neck” up and down and back and
forth very slightly. As it bent its head down-
ward, folds became apparent under its neck.
When a fish was suspended in the water, the
whale would often move alongside and examine
it with one eye. This required a certain adjust-
ment of the head which was done with great
effort because of the considerable momentum
of the large body and the limited flexure of the
head.
Some playfulness was observed. Many live
fish had been released in the pen and one day,
about a week after the whale began feeding, it
was seen chasing a 7 kg. lingcod at the sur-
face. The whale would seize the fish and toss it
a meter or more, then chase it, seize and toss it
again. This continued for about 10 minutes be-
fore the fish was eaten.
Respiration was accompanied by a noise of
very short duration consisting of a soft expira-
tion and a short, sharp inspiration. The spout
resembled a vertical puff of steam 2 to 3 m.
high (Fig. 10).
General Care of the Whale
The harpoon wound developed a mucus-like
discharge for the first few days. Penicillin was
given twice during this period. The rope itself,
when withdrawn from the wound, showed no
evidence of purulent material and did not cul-
ture pathogens.
Attention during the early stages was pri-
marily directed at means for stimulating ap-
petite. Thiamine was given both as a vitamin
and as an appetite stimulant. Atarax and vitamin
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—
B12, also thought to be helpful tor this purpose
(personal communication from David Brown),
were tried. None of these measures seemed to
help and for many weeks a pessimistic outlook
prevailed regarding the possibility that the ani-
mal would commence to eat. The animal became
very noticeably thinner during its fast.
After approximately one month in the Jericho
pen, the skin began to deteriorate from its
smooth, coal-black sheen gradually to one
covered with dull gray annular and configurate
coarse granular keratotic lesions, about 8 to 40
cm. in diameter, interspersed with sparse dis-
crete granulomatous nodules about 5 to 8 cm.
at the base and elevated 1 to 3 cm. (Fig. 5).
The lesions seemed to commence at first from
areas which had been superficially scratched at
the time of netting, but they soon spread to most
regions of the body, including the white ventral
surface. The lesions seemed superficial and,
while unsightly, were not considered a serious
threat to the animal's life.
Four weeks prior to the death of the whale
scrapings were taken of the skin lesions. Cul-
tures established that these were due to a fungal
infection, that the fungus grew best at 21 °C
and in one percent salinity. The fungus could not
be cultured at a saline content equivalent to
ocean water and grew poorly at 36.6°C.
It was hoped that the improved nutritional
status following initiation of feeding would help
to clear up the fungal infection, but the lesions
continued to develop. They appeared to advance
with extreme rapidity in the week prior to death.
Copper sulfate was applied daily with a brush for
a period of 15 days to certain regions of the
body to see if this would inhibit the fungus, but
this was without apparent effect.
Laboratory and Autopsy Findings
Physical data on the whale are recorded in
Table 2. The whale measured 467 cm. from the
tip of the snout to the notch of the flukes. It
weighed 1,040 kg. and was a male. During life,
its sex had not been determined, although it
had been suspected of being a female because of
its small size. (The name “Moby Doll” had been
chosen in a radio contest, creating an awkward-
ness when the sex was finally learned.).
Despite the fact that the animal had con-
sumed approximately 1,600 kg. of fish in the
month prior to its death, it was emaciated. The
outline of the ribs was clearly visible in the
thoractic region. Its blubber was thin, being
about 3 to 5 cm. thick around most parts of the
body.
The harpoon wound had healed well with no
sign of infection or fistula formation. It had
Table 2
Physical Measurements of Subadult Male
Orcinus orca
Length of body
467 cm.
Snout to blowhole
72 cm.
Snout to eye
57 cm.
Snout to dorsal base
206 cm.
Snout to flipper
97 cm.
Length of gape
49 cm.
Height of dorsal fin
57 cm.
Ant. -Post. Length of dorsal at base
53 cm.
Width of flipper
40 cm.
Length of flipper
66 cm.
Tail notch to top of dorsal
241 cm.
Tail notch to umbilicus
180 cm.
Tail notch to anus
149 cm.
Tail notch to genital opening
180 cm.
Width of flukes
53 cm.
Length of flukes
127 cm.
No. of teeth:
mandible— 1 1 on ea. side)
maxilla — 1 1 on ea. side )
44
Weight of body
1040 kg.
Liver
45 kg.
Lungs
L.
10 kg.
R.
9.34 kg.
Heart
6.8 kg.
Spleen
.92 kg.
Brain
6480 g.
Kidneys
L.
3680 g.
R.
4200 g.
Testes*
L.
183 g.
R.
156 g.
Adrenals*
R.
132 g.
*Weight taken after preservation for one month in
10% formalin.
entered on the left lateral side of the body, just
at the posterior aspect of calvarium. It went
through muscle and blubber and produced a chip
fracture of the occipital bone. The chip was
about 5 cm. in diameter, involving only the ex-
ternal table.
Multiple nodules were found in the lung,
subpleural in location, ranging up to 2.5 cm.
in diameter. Cultures from these nodules grew
a fungus, tentatively identified as Aspergillus
fumigatus, as well as Staphylococcus aureus and
Proteus.
Microscopic section of the lungs showed a
heavy collection of inflammatory cells, mainly
polymorphonuclear leukocytes with numerous
macrophages surrounding the nodules. In some
areas definite branching mycelia, which were
budding, could been seen.
Large lymph nodes, ranging in size from 6
to 10 cm., were located in the neck. Granu-
lomatous lesions in these enlarged nodes cul-
1966] Newman & McGeer: Capture and Care of Killer Whale 65
Table 3
Blood and Serum Values
Whole Blood
Sample 1
Sample 2
Serum Sample 1
Sample 2
Hemoglobin gm. %
—
11.3
Protein gm % —
10
White Blood Count
5500
7200
Albumin gm. %
2.4
Polymorphs %
61
33
Globulin gm. %
7.6
Staff cells %
10
21
Chloride meq/ 1
95
Eosinophils %
8
1
Sodium meq/1
148
Lymphocytes %
16
38
Potassium meq/ 1
12.3
Monocytes %
2
4
Phosphate meq/1
8.1
Hematocrit %
—
37.5
Uric acid mg. %
0.6
Carbohydrate mg. %
114
1 12
Cholesterol mg. %
280
Urea nitrogen mg. %
—
47
Phosphatase
Creatinine mg. %
—
1.5
(King Armstrong units) —
2.8
Plasma cells %
—
3
Amylase
<4
Glutamic-oxalic transaminase
units
45
Lactic dehydrogenase units —
755
Thymol turbidity units
1
Thymol flocculation units —
0
tured Aspergillus, Staphylococcus and Proteus.
Microscopic sections showed an accute inflam-
matory reaction to be present.
Each kidney contained a mycotic abscess,
measuring about 4 cm. in diameter. Microscopic
sections showed mycelia with inflammatory cells
in the abscess with complete destruction of nor-
mal tissue.
The liver had one lobe with no gall bladder.
It appeared normal grossly, but microscopic
sections showed an infiltration with polymorphs
and plasma cells. No evidence of parasites was
seen.
The stomachs were all heavily infested with
nematodes tentatively identified as Anasakis
simplex, a common parasite of the Pacific cod,
which constituted the main diet of the whale
in captivity. The rest of the gastrointestinal
tract appeared normal.
The spleen, pancreas, heart, bladder, adrenals
and genitalia all showed no evidence of path-
ology.
The skin was extensively covered with the
shallow annular and configurate lesions pre-
viously described. These were found to be en-
tirely superficial and cultured the same un-
identified fungus that had been found from the
previous skin scrapings.
The most striking organ was the brain. It
weighed 6,450 g., a remarkable size for this ani-
mal. It approached weights reported for some
of the largest species of whales (Lilly, 1964).
The only other brain weight of Orcinus so far
recorded was that of a Southern California
specimen (Caldwell & Brown, 1964), a female,
521 cm. in length, in which the brain weighed
only 4,500 g.
The cortex was extremely large and well de-
veloped with extensive convolutions. There were
two very tiny necrotic patches on the occipital
surface of the cortex, possibly reflecting a minor
degree of damage incurred at the time of the
chip fracture to the skull. Details of the ana-
tomical dissection of the brain will be reported
separately. Catecholamine and serotonin values
were obtained for a number of areas and fell in
the range already reported for other mammalian
species.
Table 3 gives various values for whole blood
and serum. Sample 1 was taken at the time the
animal was netted and Sample 2 at the time
of autopsy. Many of the values are remarkably
close to human values. The probable explanation
lor the high serum values for potassium, phos-
phate, lactic dehydrogenase and glutamicoxalic
transaminase is that Sample 2 was not obtained
until five hours after death, but abnormal levels
ante mortem cannot be ruled out. The serum
uric acid was much lower than in humans, yet
crystals morphologically identical with urate
appeared in the urine upon cooling.
Serum protein values were grossly different
from the human on chemical fractionation.
Electrophoresis established that there was mark-
edly less true albumin and markedly greater
globulin. The significance of this finding to the
pathology is hard to judge in the absence of
normal serum protein values for the killer
whale. In the second blood specimen, but not
the first, 3% plasma cells were found. Plasma
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Zoologica: New York Zoological Society
cells are occasionally seen in the peripheral
blood of humans suffering from severe infec-
tions. There was a mild shift to immature poly-
morphs in the first blood sample and a high
eosinophil count. In the second specimen, the
shift to immature cells was more marked, but
the eosinophil count dropped.
The urine values given in Table 4 are com-
parable in most respects to other mammalian
species. Sodium and potassium values are not
high, in keeping with a previous report for
humpback whales (Bentley, 1963). This is fur-
ther reinforcement for the notion that whales
obtain their water from food and metabolism
and do not drink seawater.
Aliquots of the urine were desalted and sol-
vent extracted for paper chromatography. The
amino acid chromatogram was quite similar to
that of human and rat urine. Chromatograms
of the indoles, phenolic acids and phenolic
amines showed great difference, however. Gen-
erally speaking, there were far fewer com-
pounds appearing in the whale’s urine, probably
reflecting the lack of vegetable products in the
diet.
Examination of the skeleton revealed that
the animal was very young. Carpals were al-
most non-existant and bone centers were very
small. There was much cartilaginous material.
During the dissection, the rather narrow
amount of jaw opening possible, the marked
lack of jaw mobility, the strong, dense, con-
nective tissue surrounding the temporal man-
dibular joint and the relatively minor amount
of tooth wear became evident. Once the muscles
of mastication had been completely removed
from the mandible, it was possible to open the
jaw to 37 cm. measured between the most an-
terior points on the maxillary and mandibular
alveolar crests. Further opening was prevented
by strong ligamentous attachments between the
mandible and other bones of the head. It was
not possible to move the mandible laterally
more than a centimeter either side of the mid-
line at the anterior end of the mandible.
Wear facets were noted on all of the teeth oc-
curring for the most part on both mesial and
distal surfaces. It has been reported by Carl
(1946) that wear has been observed primarily
on the anterior or mesial surface of the lower
teeth and the posterior or distal surface of the
upper teeth. This condition was noted on several
individual teeth in the Vancouver specimen.
Wear on buccal and lingual surfaces was not
prominent. This has been reported and has
been ascribed to the “varied lateral position of
the free-moving opposing lower jaw” (Caldwell
& Brown, 1964). Explanation of such wear on
Table 4
Urine Values
Specific gravity
1.024
Sodium meq/1.
58
Potassium meq/1.
65
Creatinine mg/ml.
0.58
Indican mg/ 100 ml.
1.4
Uric acid mg/ml.
0.29
the basis of mandibular mobility does not seem
tenable in the light of structures observed in
the Vancouver specimen. Some loss of tooth
structure was noted along the gingival margin
of the teeth in the Vancouver specimen partic-
ularly on the lingual surface.
Due to the thick inflexible nature of the lips
and skin, in order for the animal to open his
mouth, it is necessary to have some specialized
structures allowing elongation of the corner of
the mouth. This is accomplished in part by over-
lapping of the upper and lower lip and also by
the presence of cracks or folds at the external
side of the corner of the mouth. No ecto-para-
sites were found in these folds.
Discussion
Orcinus orca is one of the largest predatory
animals that has ever existed and it may be the
largest carnivore ever to feed on mammals. Its
wolf-pack tactics used in hunting marine mam-
mals are well known. The great abundance of
killer whales in the inner passages of British
Columbia may account for the scarcity there
of other cetaceans, very few of which, with the
exception of the harbor porpoise and occasion-
ally the minke whale, are ever seen in the Strait
of Georgia. Scheffer & Slipp (1948) consider
Orcinus as a serious factor affecting California
gray and other baleen whales on the North
Pacific coast. Yet the young specimen captured
at Saturna Island preferred fish to mammalian
flesh.
The boldness and ferocity which is so much
a recognized part of the behavior of the wild
killer whale contrasted greatly with the apparent
harmlessness of the captive specimen.
The immaturity, wounded condition and iso-
lation of the animal probably affected its be-
havior considerably. Its immaturity may have
accounted for its lack of aggressiveness. Its
wounds and subsequent skin afflicitions may
have retarded its adjustment to captivity and
delayed initiation of feeding. Isolation may well
have repressed the degree of playfulness one
would expect to find in a young delphinid.
1966]
Newman & McGeer: Capture and Care of Killer Whale
67
Support similar to that given the wounded
and stunned whale by two other members of its
pod has been described in many cetaceans (Nor-
ris & Prescott, 1961), and this behavior has
even been described between two different gen-
era (Caldwell, Brown & Caldwell, 1963). This
seems to be, however, the first time it has been
observed in Orcinus orca.
Killer whales have been benign to man. They
are very common in the inside passage of British
Columbia, with innumerable contacts between
whales and fishermen, but they have never been
reported to upset or damage boats of any size
in the area, nor have they ever been reported to
attack swimmers or skin divers. Stephens (1963)
reports six known encounters between divers
and killer whales in various parts of the world
without the former being threatened or harmed
in any way. The report of Marineland collectors,
whose boat was struck by an orca in 1962, is an
exception.
Cook & Wisner (1963) related the story of a
fisherman aboard a boat off Long Island, New
York, who cast a hand-held harpoon into the
back of a killer whale that approached the boat.
The whale pulled free of the harpoon and then
followed the boat until it reach shallow water.
It never struck the boat or manifested any re-
taliatory actions, although the people in the boat
described their terror at being followed.
Severe tooth wear in adults has been described
by Carl (1946) and by Caldwell & Brown
( 1964) . This wear must be a serious debilitating
factor affecting the predatory and feeding be-
havior of the adult. Possibly this explains the
preference for the tongue of the great baleen
whales. Such tongues consist of soft, watery tis-
sue which would be relatively easy to tear by
blunt, worn teeth.
Hancock ( 1965) described an attack by seven
killer whales on a rorqual near Vancouver Is-
land. He said that the two calves, which were
about 4 meters in length, remained close to the
females while the three males were 300 meters
ahead when first observed. Very little could be
observed at the surface while the orcas were
killing and devouring the rorqual. Later, the
corpse was found to be lacking the tongue and
the entire outer skin. The body was intact except
for a small tear in the abdomen. It would be
valuable to have more field observations on their
feeding behavior.
The refusal of the animal to take any food
for 54 days after capture was extremely frus-
trating. It has been observed ( Brown, 1 962) that
pilot whales seem to withstand prolonged fasting
with far less weight loss than the small delphi-
nids. One of these animals survived 14 days of
fasting without apparent weight loss.
It is not possible to say with certainty why the
whale died. The most striking pathological find-
ings were the mycotic infection of the lungs,
kidneys and lymph nodes, plus an indication of
secondary bacterial infection in these areas. The
white blood count showed a distinct shift to the
left but not an extreme elevation in count. The
infection of the skin was from a different fungus
than that infecting the lungs, kidneys and lymph
nodes. Although it looked severe, it was never-
theless entirely superficial and probably did not
contribute to the death of the whale. The same
could be said for the nematode infestation.
While heavy, it was entirely confined to the
stomach. Such infestations are compatible with
good health in many species.
The pathological findings would seem to indi-
cate death from a widespread mycotic infection
with a superimposed terminal bacterial infec-
tion. There were other obvious contributing fac-
tors. The extended fast depleted body reserves.
The enervating effects of acute mycotic and bac-
terial infections together with the debilitated
condition of the animal probably led to exhaus-
tion and drowning in the water of low salinity.
Although the saline content varied consider-
ably during the time the animal was in captivity
and although the water was often muddy, there
was no evidence of clouding of the cornea, which
has been reported to occur in dolphins and some
seals kept under conditions of low salinity.
The size of the brain and the high degree of
development of the cortex would suggest the
possibility of advanced intelligence of this spe-
cies. It seems highly probable that they could
be trained and that they would not be particu-
larly dangerous.
Methods for capturing killer whales need to
be devised. It was extremely lucky that this par-
ticular animal was not killed by the initial har-
poon shot. Had the harpoon struck slightly
caudally, it would have penetrated the cervical
cord. Slightly rostrally, it would have penetrated
the brain.
The water in which the whale was maintained
was obviously unsuitable. What special prob-
lems might accrue in the way of warding off
infection and devising a thoroughly suitable diet,
still remain to be determined.
Summary
1. A young, male killer whale (Orcinus orca)
was harpooned at Saturna Island, Strait of
Georgia, British Columbia, and towed to Van-
couver where it was maintained alive for 86
days.
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[51: 5
2. The captive whale fasted 54 days after
which it began eating 45-90 kg. of fish per day.
It became fairly tame and could be fed by hand.
3. Its behavior consisted mainly of counter-
clockwise swimming, during which it was sub-
merged out of sight for an average period of 90
seconds with only a few seconds at the surface
for respiration.
4. Two distinct types of sound were produced.
One type consisted of clicks, evidently con-
cerned with echo location. The other consisted
of whistles and squeaks, presumably a form of
communication.
5. Soon after capture, the whale was given 30
million units of S.R. penicillin. Six days later, it
was given a further injection of 15 million units
of S.R. penicillin and one gram of thiamine.
Three weeks after capture, it was netted, in-
jected with an additional 30 million units of S.R.
penicillin, one gram of thiamine, 1.5 mg. of
vitamin B12 and one gram of atarax. A blood
sample was taken at this time.
6. Annular, keratotic lesions began to appear
on the skin late in August and grew progres-
sively worse.
7. The whale died on October 9, at which
time the salinity of the water in its enclosure
was only 12 per thousand, one-third that of the
open ocean. Nodules in the lung, lymph nodes
and kidneys following autopsy cultured Asper-
gillus, Staphlyococcus and Proteus. The stomach
was heavily infested with nematodes.
8. Maximum jaw opening was 37 cm. Lateral
jaw movement was only a centimeter. There
were 1 1 teeth in each quadrant. Wear facets
existed on both mesial and distal surfaces.
9. The experience indicated the feasibility of
maintaining and possibly training killer whales
in captivity.
Acknowledgments
The whale was harpooned by Mr. S. Burich
and Mr. Josef Bauer. Its capture was made pos-
sible through the cooperation of Mr. C. Levelton
and Capt. M. Gay of the Department of Fisher-
ies and Mr. P. H. Quinney and Mr. P. Fletcher
of the East Point Light House. Burrard Drydock
facilities were made available by Mr. David
Wallace. Lt. Col. W. H. V. Matthews permitted
the construction of a pen at the Jericho Military
Base. Major H. Robertson (retired), Capt. J. C.
Grey (RCN), Lt. Comdr. A. Rowse (RCN)
organized the construction of the pen. Medical
assistance and advice in the care of the whale
was freely given by Drs. J. H. Sturdy, R. A.
McKechnie, W. H. Cockroft, D. H. Williams,
John Eden, D. G. Middaugh, W. C. Gibson and
R. A. English. Data were supplied by Mr. Ian
MacAskie, Mr. Gordon Pike, Mr. M. Bigg, Dr.
J. H. Sturdy, Dr. R. A. English, Dr. W. H.
Cockroft, Dr. John Eden, Dr. H. D. Fisher,
Dr. D. G. Middaugh, Dr. E. G. McGeer and
Dr. J. R. Adams. Assistance with the manuscript
was given by Dr. H. D. Fisher, Mr. V. Penfold
and Mr. J. Bauer. The Royal Canadian Navy
at Esquimalt loaned sound equipment. The Leon
and Thea Koerner Foundation and the Van-
couver Public Aquarium Association provided
grants.
Addendum
An adult male Orcinus orca and a juvenile
were accidentally trapped within a gillnet at
Namu, British Columbia, in June, 1965. The
small specimen escaped but the large one (Fig.
1 1 ) was purchased by Edward I. Griffin, who
built a floating cage 60 x 40 x 16 feet deep and
transported the animal to Seattle, a distance of
450 miles. The animal, which was 21.5 feet long
and weighed 7,800 pounds, quickly became tame
and permitted divers to swim with it, never man-
ifesting predatory or aggressive inclinations. It
ate mainly salmon, consuming 300-400 pounds
per day. It died July 9, 1966.
A small female, about 14 feet in length, was
captured by Griffin in Puget Sound in November,
1965. This specimen was flown to San Diego
where it is on public exhibit in an oceanarium.
It is quite tame, eats only fish and has learned
to perform various tricks including leaping out
of the water for its food.
References
Bentley, D. J.
1963. Composition of the urine of the fasting
humpback whale. Comp. Biochem. Phy-
siol., 10: 257-259.
Brown, D. H.
1960. Behavior of a captive Pacific pilot whale.
Jour. Mamm., 41 (3): 342-349.
1962. Further observations on the pilot whale in
captivity. Zoologica, 47 (1): 59-64.
Brown, D. H., R. W. McIntyre, C. A. Delli
Quadri & R. J. Schroeder
1960. Health problems of captive dolphins and
seals. 137 (9): 534-538.
Brown, D. H. & K. S. Norris
1956. Observations of captive and wild cetacea.
No. 1. Jour. Mamm., 37 (3): 120-145.
Caldwell, D. K. & D. H. Brown
1964. Tooth wear as a correlate of described
feeding behavior by the killer whale, with
notes on a captive specimen. Bull. South-
ern Calif. Acad. Sci., 63 (3): 128-140.
1966]
Newman & McGeer: Capture and Care of Killer Whale
69
Caldwell, M. C., D. H. Brown & D. K. Caldwell
1963. Intergeneric behavior by a captive Pacific
pilot whale. Contrib. Sci. L. A. County
Mus., 70: 1-12.
Carl, G. C.
1946. A school of killer whales stranded at
Estevan Point, Vancouver Island. Rept.
Prov. Mus. Nat. Hist. & Anthr. pp. 21-28.
Cook, J. J. & W. L. Wisner
1963. Killer whale. Dodd, Mead. New York 64
pp.
Evans, W. E. & I. H. Prescott
1962. Observations of the sound production
capabilities of the bottlenose porpoise: A
study of whistles and clicks. Zoologica, 47
(3): 121-128.
Hancock, D.
1965. Killer whales kill and eat a minke whale.
Jour. Mamm 46 (2) : 341-342.
Kellogg, W. N.
1961. Porpoises and Sonar. Univ. Chicago Press.
177 pp.
Layne, J. N. & D. K. Caldwell
1964. Behavior of the Amazon dolphin, Inia
geoffrensis (Blainville), in captivity. Zoo-
logica, 49 (2) : 81-108.
Lilly, J. C.
1961. Man and Dolphin. Doubleday, N.Y., 312
pp.
1964. Arrivals in aquatic environments, adapta-
tion of mammals to the ocean. In: Hand-
book of Physiology, Section 4: Adaptation
to the Environment. Am. Physiol. Society.
Scheffer, V. B. & J. W. Slipp
1948. The whales and dolphins of Washington
State with a key to the cetaceans of the
west coast of North America, Amer. Midi.
Nat., 39 (2): 257-337.
Stephens, W. M.
1963. The Killer. Sea Frontiers, 9(5): 262-273.
Wood, F. G. Jr.
1953. Underwater sound production and con-
current behavior of captive porpoises, Tur-
siops truncatus and Stenella plagiodon.
Bull. Mar. Sci. Gulf and Carib., 3 (2):
120-133.
70
Zoologica: New York Zoological Society
[51:5
Explanation
Pl. I
Fig. 1. Samuel Burich about to fire harpoon at
killer whales on July 16, 1964, at Saturna
Island, British Columbia. Photo by J.
Bauer.
Fig. 2. Head of young male Orcinus showing har-
poon which passed through muscle and
blubber just posterior to calvarium.
Photo by D. Middaugh.
Pl. II
Fig. 3. Orcinus struggling on harpoon line secured
to suspended stage above. Note white
undersides of flukes.
Photo by D. Middaugh.
Pl. Ill
Fig. 4. Injecting penicillin into the animal with
syringe at the end of a pole.
of Plates
Pl. IV
Fig. 5. Side of whale showing annular keratotic
lesions on skin.
Pl. V
Fig. 6. The whale seizing a Pacific cod from the
hand of the senior author.
Photo by Brian Kent.
Pl. VI
Fig. 7. Sonograph of whale’s whistling sound.
Fig. 8. Sonograph of navigational clicks.
Pl. VII
Fig. 9. Whale leaping out of water.
Pl. VIII
Fig. 10. The spout resembled a vertical puff of
steam 2 to 3 meters high.
Fig. 11. Edward Griffin swimming with the adult
male killer whale at the Seattle Aquarium.
NEWMAN & Me GEER
PLATE I
FIG. 1
FIG. 2
THE CAPTURE AND CARE OF A KILLER WHALE (ORCINUS ORCA )
IN BRITISH COLUMBIA
NEWMAN & Me GEER
PLATE II
FIG. 3
THE CAPTURE AND CARE OF A KILLER WHALE (ORCINUS ORCA )
IN BRITISH COLUMBIA
FIG 4
NEWMAN & Me GEER
PLATE III
THE CAPTURE AND CARE OF A KILLER WHALE (ORCINUS ORCA)
IN BRITISH COLUMBIA
NEWMAN & Me GEER
PLATE IV
FIG. 5
THE CAPTURE AND CARE OF A KILLER WHALE (ORCINUS ORCA )
IN BRITISH COLUMBIA
NEWMAN & Me GEER
PLATE V
FIG. 6
THE CAPTURE AND CARE OF A KILLER WHALE (ORCINUS ORCA)
IN BRITISH COLUMBIA
NEWMAN a Me GEER
PLATE VI
FIG. 8
THE CAPTURE AND CARE OF A KILLER WHALE (ORCINUS ORCA)
IN BRITISH COLUMBIA
NEWMAN & Me GEER
PLATE VII
FIG. 9
THE CAPTURE AND CARE OF A KILLER WHALE (ORCINUS ORCA )
IN BRITISH COLUMBIA
NEWMAN & Me GEER
PLATE VIII
FIG. 10
FIG. 11
THE CAPTURE AND CARE OF A KILLER WHALE (ORCINUS ORCA)
IN BRITISH COLUMBIA
6
Sound Structure and Directionality in Orcinus (killer whale)
William E. Schevill & William A. Watkins1
(Figures 1-5)
Introduction
Orcinus orca (Linne) 1758, the killer whale,
has long been noticed and spoken of
under a wide variety of vernacular and
technical names. For all the attention devoted to
it, very little has been noted, or at any rate re-
corded, of its phonation (or sound production).
Grieg ( 1907) describing the trapping and killing
of 47 killers, mentioned what he called flute-like
sounds from the young and roars from the old
bulls. Valdez (1961) described killer whale clicks
as heard by ear through the hull and as recorded
on an echo-sounder in the first published refer-
ence to hearing this species under water. Schevill
(1964, p. 313) listed unpublished recordings by
the Royal Canadian Navy (made in June, 1956,
along the west coast of the Queen Charlotte
Islands and on February 19, 1958, in Saanich
Inlet, Vancouver Island, B. C.) and by the United
States Navy (on October 20, 1 960, in Dabob Bay,
Hood Canal, Washington). As far as we know,
these are the only recordings made before the
capture of the Vancouver killer, which was har-
pooned in the Strait of Georgia July 16, 1964
(Newman 1964, 1964a). The underwater calls
of this young bull were recorded by Dr. Patrick
L. McGeer of the University of British Colum-
bia and by us (this study). Mr. Gerald Kooy-
man of the University of Arizona has generous-
ly given us some of his Orcinus recordings of
January, 1965, in McMurdo Sound, Ross Sea.
The present study is based on our own tapes,
although we have had the benefit of comparison
with those just listed. The captivity of Mr. Ted
Griffin’s Namu-Seattle Orcinus in 1965 has led
to a great deal of recording by several workers,
not reported at the time of writing.
1 Contribution No. 1787, Woods Hole Oceanographic
Institution.
Material and Methods
Our records were made from August 16 to
18, 1964, on our portable Rowboat Recorder
( Watkins, 1963), which has a flat response from
30 cps to 30 kcps. Our subject was the young
bull Orcinus at Vancouver, British Columbia,
captured a month before (Newman, 1964,
1964a). At its death after 12 weeks of captivity,
this animal was 4.67 m long and weighed 1,034
kg. The pen in which it was confined was cut
out of an old wharf and measured about 14 by
23 m, with a water depth from 3 to 7.5 m, de-
pending on the tide. The water was chiefly
Fraser River outflow of very low salinity and
high turbidity. Since the sides of the pen were
of coarse wire mesh and the water was simply
part of the bay, in which there was very little
traffic, the acoustic conditions were far and
away superior to the tanks in which captive
cetaceans are usually confined. Not only were
we free of the noises of pumps and land traffic,
but the coarse mesh sides did not return the
troublesome echoes of the usual tanks. Especial-
ly at night, when the bay traffic virtually ceased,
we had listening conditions approaching the best
at sea.
Phonation and Concomitant Behavior
A striking feature of this whale's phonation
was the total absence of the familiar delphinid
whistle-like squeal. All the sounds recorded were
clicks, or composed of clicks, which themselves
were unlike those of typical delphinids. When
these clicks were repeated sufficiently slowly,
they were individually recognizable (Figs. 3-5);
when the repetition-rate was greatly increased,
the effect was strikingly different (Fig. 2): a
strident scream resulted, often quite loud (we
estimate more than 60 db re 1 dyne/cm2 at 1 m
from the source). Because of the rapid click-
rate (too rapid to show much more than the
71
72
Zoologicu: New York Zoological Society
[51: 6
sharp front characteristic of separate clicks),
these screams are rich in harmonics. As noted
further on, it is our impression that these strident
screams are used for communication (calling),
while the separate clicks appear to be used like
the more familiar delphinid click (as in Tursiops
truncatus, for example), apparently in echolo-
cation.
The whale’s habitual circuit of its pen was
counterclockwise at speeds of 2 to 4 knots, the
loop usually taking 35 seconds. It often blew
(respired) once a circuit, but sometimes made
two or three circuits on one breath. This routine
seemed to be interrupted only at times of call-
ing. (The whale had not then begun to accept
hand-feeding. )
The calling appeared to be stimulated by the
passing of small boats and occurred both by day
and especially by night. During the 3 to 5 min-
ute calling periods, the whale sometimes slowed
its swimming or executed smaller circles, often
near the gate. The strident screams were con-
sistently loud enough to be heard plainly in air.
There would be 30 to 50 of these screams, each
lasting usually less than a second and separated
one second or more, the spacing increasing until
the last calls might be 15 to 30 seconds apart.
The final two to five calls ordinarily were longer,
lasting as much as 3 seconds. During these call-
ing periods there were very few or no slow
clicks between the screams, as if to reduce local
interference in favor of careful listening.
During daylight the whale was silent except
for infrequent screams, but at night each circuit
of the enclosure was accompanied by either
steady clicking (2 to 6 per second) or by bursts
of slow clicks, a few seconds only between bursts.
We had the following hints that the clicks
were used in echolocation. The hydrophone with
its preamplifier case (greatest dimensions 4 X
30 cm) was maneuvered into the whale’s path by
means of an overhead line. During clicking per-
iods at night the whale never touched the hydro-
phone or the cable above. But during nocturnal
calling periods when the whale circled without
clicking, it collided with the hydrophone every
time the unit was in its way. There were no
exceptions— when clicking, the whale avoided
all contact with the hydrophone, but when no
clicks were heard from the whale a collision
could be arranged. Usually immediately follow-
ing such a collision, the whale would click for
a short period. The whale never hit the hydro-
phone more than once in the same spot; if the
hydrophone was left in the same position, no
other collisions were noted on successive circuits,
even though no clicks were heard.
The whale easily avoided the hydrophone dur-
ing daylight without clicking. Probably this was
simply because it could see.
Clicks
The clicks of other delphinids typically are
broad-band (for example, Lilly, 1962, fig. 3;
Evans & Prescott, 1962, PI. 1; Schevill & Wat-
kins, 1962, various figs.). Those of Orcinus, on
the other hand, have discrete and rather low
frequencies for main components, somewhat
like those of certain seals (Schevill, Watkins,
& Ray, 1963). The Orcinus click has a short
enough rise-time to give this pulse many high
frequency components as well, but at lower
amplitudes. The main part of the click is nar-
row-band and has predominant frequencies with
a decaying amplitude (Fig. 1). The click dura-
tion is between 10 and 25 milliseconds, depend-
ing on its amplitude above ambient. The dura-
tion of the click, the restricted frequency em-
phasis, and the decaying amplitude of the pulse
point to a resonance in the click-making mech-
anism. The fundamental frequency of these
click-pulses (the resonant frequency) varied be-
tween 250 and 500 cps.
The fundamental frequency of clicks in a
group may vary from one click to the next.
Characteristically, the clicks were emitted in
short bursts, 10 to 15 clicks in each burst, with
the first clicks at both a faster repetition-rate
and a slightly higher frequency emphasis. A
typical burst of 12 clicks starts with a repetition-
rate of 18 clicks per second with a 500 cps
fundamental frequency, and ends with a repeti-
tion-rate of 6 clicks per second with a frequency
of 350 cps. Slow click repetition-rates appear to
be characteristic of the species.
Screams
Much variation is evident in the killer whale
recordings known to us, but certain patterns
appear to fit them all. The screams of Orcinus
are characterized ( 1 ) by a strident quality re-
sulting from the strong harmonic structure, indi-
cating that these calls are pulsed, (2) by being
generally of two parts, and (3) by each part
having a lingering dominant repetition-rate fre-
quency which is generally relatively low, about
500 and 2,000 cps.
On spectrographic as well as oscilloscopic
analysis, Orcinus screams are seen to be com-
posed of rapid pulses. In spectrographic pres-
entations this is often indicated by the presence
of many strong harmonics (for a detailed ex-
amination of this phenomenon, see Watkins, in
press). These harmonics are largely the product
of the pulse repetition-rate, which may be read
directly from the harmonic interval, and it is they
1966]
Schevill & Watkins: Sound Structure in Orcinus
73
that account for the very strident quality of these
screams. This structure with many strong har-
monics indicates that it is composed of relative-
ly short-rise-time pulses containing many fre-
quencies; these pulses, when produced slowly
enough to be separated, are not unlike the slower
Orcinus echolocation clicks discussed above. In-
deed, many screams start with relatively slow
clicks whose repetition-rate is increased until the
rate of the scream fundamental is reached ( Fig.
2). Other screams end with a decreasing pulse
repetition-rate, which continues slowing until
the clicks may be easily separated. Occasionally,
a slow burst of clicks may be increased in repeti-
tion-rate until it ends in the typical strident
scream and vice versa. At no time were the slow
clicks and the screams produced concurrently
by our solitary animal, (as has been noted for
clicks and squeals in Tursiops (Lilly & Miller,
1961) and other delphinids). The clicks do not
appear to change much in frequency-composi-
tion at increased repetition-rates, but in the
scream, when clicks are produced too rapidly
to be separate, the repetition-rate harmonic
structure is dominant and masks most individual
click components. It appears likely that the
screams are made by the same mechanism that
produces the clicks. This hypothesis is strength-
ened by our strong impression that they had
the same frequency and sound field character-
istics, relative to the physical orientation of the
animal, as were noted in the echolocation clicks.
Two-part screams appeared to be favored
by the captive Orcinus, each part having a differ-
ent predominant repetition-rate frequency. This
whale appeared to have preferred 500 cps and
2,000 cps. It hit these notes again and again. A
typical scream began with a rapid rise in repeti-
tion-rate frequency until 500 cps was reached;
then that note was held for the first half of the
call, and following another sliding shift in repeti-
tion-rate frequency, 2,000 was held. A scream
may also have the 2,000-cps part at the begin-
ning with the second part at 500 cps. The end
could be another shift, either up or down, or it
could trail off at that note. A long call could have
as many as five alternations. The subtleties of
beginnings and endings of screams could be lost
quickly at a distance because of their relatively
low amplitude.
The duration of the screams was generally a
little less than one second. Calls from 0.1 to 3.0
seconds long have been noted, with 0.65 seconds
as the average length.
Sound Projection Pattern
The frequency content and amplitude of the
clicks produced by the Vancouver captive varied
strikingly with the orientation of the animal.
When the whale faced the hydrophone the high
frequency components of the clicks were clearly
audible, but as the whale turned, these high
frequencies diminished progressively (Fig. 3)
until only the lowest click components could be
heard behind it. Even the low frequency parts
of the clicks were harder to hear when the whale
was headed away from the hydrophone, indicat-
ing that the total sound field also varied with
orientation. The clicks were fairly low level. With
the animal facing the hydrophone, the clicks
were estimated to be only -10 to -20 db at one
meter, relative to one dyne per cm-', and were
often less than 10 db above ambient at one
meter. Thus the whale's clicking at times could
not be heard until it was quite close and closing
range. The intensity of the clicks would increase
as the whale approached, and as it turned to
avoid the hydrophone it presented the duller
areas of its sound projection pattern. The high
frequency content of the clicks thus tended to
increase as the clicks became louder and then
decrease as the whale turned away from the
hydrophone. Nevertheless, the low frequency
components became progressively louder as the
animal came closer (Figs. 4A & 4B). Depend-
ing on the amplitude of the signal, it was pos-
sible to lose all harmonics and retain only the
click fundamental as the animal went past
(Fig. 5).
It was impossible to keep exact track of the
whale’s orientation as it circled the enclosure
at night, but the dim yard lights of the adjacent
compound and the rippled surface of the water
as the whale's fin passed beneath, together with
the animal’s periodic surfacing, helped give an
impression of its position. On a few fortunate
occasions, the whale circled virtually at the sur-
face all the way, giving a good check on previous
observations. It was possible to correlate click
quality (relative presence of high frequencies)
and intensity with the location and orientation of
the whale.
A 20° shift in orientation from directly ahead
gave a detectable difference in the quality of
the click to the human ear. A 90° orientation
change reduced the intensity of the 3 to 4 kcps
components in the signal by an estimated 4 to
6 db. This was sufficient to cause the apparent
loss of all harmonics during constant amplitude
analyses of low level clicks. At close quarters
and directly ahead of the whale there was
energy to above 20 kcps, but at a distance and
off to the side the fundamental of the click
was all that was heard. No high frequency em-
phasis was noted within the 30 kcps bandwidth
of these recordings. A broader bandwidth re-
cording system might have detected higher
74
Zoologica: New York Zoological Society
[51: 6
frequency components in the head-on sound
cone, since these pulses evidently have a very
short rise-time.
The idea that odontocetes have a definite and
functional sound projection pattern has slowly
been growing. Norris, Prescott, Asa-Dorian &
Perkins (1961) noted that 100 kcps components
of the clicks of Tursiops truncatus were received
only when the porpoise pointed its rostrum di-
rectly at a sharply tuned hydrophone. The au-
thors postulated (p. 172) that “the degree of
directionality may vary systematically with fre-
quency.” Lilly ( 1962, p. 523) repeats the obser-
vation of the narrow forward 100 kcps beam.
Evans & Prescott (1962) described the broad-
band sound pressure pattern received through
severed heads of Tursiops truncatus and Stenella
graffmani as being markedly stronger ahead and
to the right side. Norris ( 1964, p. 327) predicted
that "it seems likely that such asymmetry will be
found to extend to frequency and harmonic
composition as well.”
Evans, Sutherland & Beil (1964) argued that
these directional characteristics could result sim-
ply from the physical shape of the skull of these
animals. Their measurements, made on another
species of Stenella and a skull of Tursiops trun-
catus, showed a varying sound field with respect
to the orientation of the head at any one fre-
quency and an appreciable attenuation at 50 and
70 kcps downward and to the rear. Romanenko,
Tomilin & Artemenko (1965), in a similar ex-
periment with both a head and bare skull of
Delphinus delphis, showed (their Fig. 2) the hori-
zontal sound field for nine frequencies from 10
to 180 kcps. Their plots are similar, but with
asymmetry to different sides at different fre-
quencies, and their patterns are sharper.
While the shape of the upper forward surface
of the skull may be a reflector (Norris, 1964),
the mere obstructive presence of the skull and
body behind the sound source may be the major
factor in the rearward and downward attenua-
tion of the sound field. Further, we have the still
unproved possibility that the fatty melon may
function as an acoustic lens (Norris, et al., 1961 ;
Norris, 1964).
Our experience with the Vancouver Orcinus
supports and somewhat extends these ideas. Per-
haps the melon is dominant in focussing the
sound transmissions, for the rather flat face of
the Orcinus skull does not seem suitable for
forming as sharp a high-frequency beam as we
have observed. It is high time for some real
acoustic measurements of this mass of nasal fat.
Characteristics of Orcinus Phonation
We have alluded to some conspicuous differ-
ences between the phonation of the single cap-
tive Orcinus orca in Vancouver and that of its
relatives, the smaller delphinids.
1. The whistle-like squeal of the smaller del-
phinids, which they appear to use for communi-
cation, was never heard from the V ancouver cap-
tive. We have not recognized it in the other
recordings of Orcinus. The U. S. Navy recording
of October 20, 1960, in Dabob Bay, includes a
very few squeals, but it is not certain what made
them (this record also includes a few human
whistles made over an underwater transmitter).
It is possible that these squeals were made by
some unseen delphinid, perhaps at a consider-
able distance. It is also conceivable that they
were made by some of the small calves in that
group of Orcinus, but we have yet no other hint
that Orcinus baby-talk may include squeals, ex-
cept perhaps Grieg’s (1907) “fluting sound.”
Further evidence that squeals are not part of
the Orcinus repertory is the use of the screams
(markedly pulsed calls) when one would have
expected a small delphinid to squeal. When our
captive screamed, it was apparently trying to
communicate (stimulated by outside disturb-
ance, usually a passing boat) . The screams were
much louder than the clicks, just as, at sea, the
communicative squeals of delphinids are ordi-
narily heard further than their clicks.
2. Orcinus clicks are unlike those of any other
delphinid known to us and are distinguished by
their emphasis of discrete fundamental frequen-
cies. They are narrow-band and low frequency;
typical delphinid clicks are broad-band, though
there may be some local emphasis at certain
frequencies. Valdez (1961) evidently noted this
marked difference in pitch when he rendered
the clicks of his Lagenorhynchus “hin, hin, hin”
and those of Orcinus “him, him, him;” he also
noted that (as may be seen in his figures) the
former are very much shorter than the latter. His
estimates of signal lengths of less than .5 m and
1 to 2 m, respectively, are, considering the diffi-
culty of making sharp measurements on an
echo-sounder record, consonant with our own
timing of 2 to 3 msec and 10 to 25 msec.
There is some resemblance to the clicks of
Phocoena phocoena (Linne) 1758, which, as
shown by Busnel, Dziedzic & Andersen (1963)
and in recordings by Carleton Ray from New
Brunswick (Passamaquoddy Bay), are also nar-
row-band and low frequency, but at about 2
kcps, which is markedly higher than Orcinus.
Phocoena is not closely related to Orcinus; it
is a member of a different family, Phocoenidae,
which is plainly distinct morphologically. Inci-
dentally, we have never heard a squeal from
any phocoenid (we have listened to Phocoena
and Phocoenoides at sea) nor have we heard of
1966]
Schevill & Watkins: Sound Structure in Orcinus
75
one from others who have listened at sea or to
captives.
Study of the recordings of groups of free
Orcinus by others mentioned above encourages
us to suppose that these differences are not
peculiar to our one specimen, but are valid for
the species.
Acknowledgments
We are grateful to a number of people for
helping us, especially Drs. Murray A. Newman,
H. Dean Fisher, and Patrick L. McGeer in Van-
couver for access to the whale and hospitality
while there, Drs. Ford Wilke (U. S. Fish and
Wildlife Service, Seattle) and Cedric Lindsay
(Washington State Shellfish Laboratory at Quil-
cene) for the Dabob Bay recordings and infor-
mation, Dr. Allen R. Milne (Pacific Naval Lab-
oratory, Esquimault) and Dr. Gordon C. Pike
(Fisheries Research Board of Canada, Nanaimo)
for copies of the Canadian recordings, and Mr.
Gerald L. Kooyman (University of Arizona)
for field recordings from the Ross Sea.
This study was supported by the U. S. Navy
Office of Naval Research, through Contracts
Nonr 4446 and Nonr 4029, and by the National
Science Foundation, Antarctic Research Pro-
grams, through Grant GA 141.
References
Busnel, Rene-Guy, Albin Dziedzic &
Soren Andersen
1963. Sur certaines caracteristiques des signaux
acoustiques du Marsouin Phocoena pho-
coena L. Comptes Rendus, Acad. Sci.
Paris, 257, pp. 2545-2548, 2 text-figs.
Evans, William E. & John H. Prescott
1962. Observations of the sound production cap-
abilities of the bottlenose porpoise: A
study of whistles and clicks. Zoologica,
47, pp. 121-128, 4 pis., 6 text-figs.
Evans, W. E., W. E. Sutherland & R. G. Beil
1964. The directional characteristics of delphinid
sounds. Marine Bio-Acoustics, W. N.
Tavolga (ed.), pp. 353-370, 15 text-figs.
Grieg, James A.
1907. Nogle notiser fra et spaekhuggerstaeng
ved Bildostrbmmen i januar 1904. Bergens
Museums Aarbog 1906, 2, 28 pp., 8 text-
figs.
Lilly, John C. & Alice M. Miller
1961. Sounds emitted by the bottlenose dolphin.
Science, 133, 3465, pp. 1689-1693, 4 text-
figs.
Lilly, John C.
1962. Vocal behavior of the bottlenose dolphin.
Proc. Amer. Philos. Soc., 106, 6 pp. 520-
529, 11 text-figs.
[Newman, M. A.]
1964. Captive killer whale. Vancouver Public
Aquarium Newsletter, 8, 6, pp. 1-6, 4 figs.
[Newman, M. A.]
1964a. Death of Moby Doll. Vancouver Public
Aquarium Newsletter, 8, 7, pp. 1-2, 3 figs.
Norris, K. S.
1964. Some problems of echolocation in ceta-
ceans. Marine Bio- Acoustics, W. N. Tav-
olga (ed.), pp. 317-336, 5 text-figs.
Norris, Kenneth S., John H. Prescott,
Paul V. Asa-Dorian, & Paul Perkins
1961. An experimental demonstration of echo-
location behavior in the porpoise, Tursiops
truncatus (Montagu). Biol. Bull., 120, pp
163-176, 4 text-figs.
Romanenko, E. V., A. G. Tomilin &
B. A. Artemenko
1965. K voprosu o zvukoobrazovanii i napravl-
ennosti zvukov u delphinov [Concerning
the problem of sound-production and di-
rection of sounds by dolphins], Bionika
(Akad. Nauk SSSR, Sci. Council Complex
Probl. Cybern.) pp. 269-273, 3 text-figs.
Schevill, W. E.
1964. Underwater sounds of cetaceans. Marine
Bio-Acoustics, W. N. Tavolga, (ed.), pp.
307-316.
Schevill, William E. & William A. Watkins
1962. Whale and porpoise voices, a phonograph
record. 24 pp., 35 text-figs., phonograph
disk. Woods Hole Oceanographic Institu-
tion, Woods Hole, Mass.
Schevill, William E.. William A. Watkins &
Carleton Ray
1963. Underwater sounds of pinnipeds. Science,
141, 3575, pp. 50-53, 5 text-figs.
Valdez, V.
1961. Echo sounder records of ultrasonic sounds
made by killer whales and dolphins. Deep-
Sea Research, 7, 4, pp. 289-290, 4 figs.
Watkins, William A.
1963. Portable underwater recording system.
Undersea Technology, 4, 9, pp. 23-24, 4
text-figs.
Watkins, William A.
(In press.)
Harmonic interval: fact or artifact in spec-
tral analysis of pulse trains. Marine Bio-
Acoustics, 2, W. N. Tavolga. (ed.).
76
Zoologica: New York Zoological Society
[51:6
EXPLANATION OF FIGURES
Figure 1
A. An oscilloscope picture of one recorded click
emitted by the Orcinus nearly head-on toward the
hydrophone.
B. A click recorded less than 2 seconds later when
the whale was nearer the hydrophone, but turned
somewhat away from it. Note the high amplitude
high-frequency components of the beginning of the
pulse in A and the higher amplitude low frequencies
in B. The grid divisions are 2 milliseconds apart.
Figure 2
A typical scream of Orcinus. Note the clicks sepa-
rated at the beginning and the two single-frequency
sections of the call at 2,000 and 500 cps. The ana-
lyzing filter bandwidth is 200 cps.
Figure 3
A succession of Orcinus clicks produced as the
animal turned a few degrees horizontally. During
the first of these clicks the whale was coming nearly
head on; note the progressive loss of high frequen-
cies even though the animal was getting closer. Ana-
lyzing filter bandwidth is 400 cps.
Figure 4A
Orcinus clicks received as the animal was heading
toward the hydrophone.
Figure 4B
As the whale went past. The high-frequency com-
ponents have dropped out of the clicks, although
the low frequencies are very much louder with prox-
imity. B was about 1.5 seconds after A. Analyzing
filter bandwidth is 400 cps.
Figure 5
A series of clicks produced by the Orcinus as it
approached and passed the hydrophone. Note the
single-frequency emphasis (fundamental) of the
clicks, as well as the loss of the second harmonic as
the whale comes alongside the hydrophone. The
amplitude of the main lower frequency component
of the clicks, however, increases with the whale’s
proximity. This time the animal passed a meter or
so away and had not headed directly toward the
hydrophone, so that only the lower frequencies
show. The vertical line in the middle and the blobs
at the bottom of the spectrogram are noise. Analyz-
ing filter bandwidth is 60 cps.
SCHEVILL & WATKINS
PLATE I
1
B
FIG. 1
SOUND STRUCTURE AND DIRECTIONALITY IN ORCINUS (KILLER WHALE)
SOUND STRUCTURE AND DIRECTIONALITY IN ORCINUS (KILLER WHALE)
SCHEVILL & WATKINS
PLATE II
kcps
SOUND STRUCTURE AND DIRECTIONALITY IN ORCINUS (KILLER WHALE)
SCHEVILL & WATKINS
PLATE 111
SOUND STRUCTURE AND DIRECTIONALITY IN ORCINUS (KILLER WHALE)
SCHEVILL & WATKINS
TIME - SECONDS
ro
PLATE IV
<J)
kcps
SOUND STRUCTURE AND DIRECTIONALITY IN ORC1NUS (KILLER WHALE)
SCHEVILL & WATKINS
PLATE V
TIME -SECONDS
<T>
kcps
SOUND STRUCTURE AND DIRECTIONALITY IN ORCINUS (KILLER WHALE)
SCHEVILL & WATKINS
PLATE VI
CJ1
o
o
1000
7
Effects of Vitamin Antimetabolites on Lebistes reticulatus.
George S. Pappas
New York University & Iona College, New Rochelle, N. Y.1
(Text-figures 1 & 2)
Introduction
THE role of vitamins in the nutrition of
fishes poses a complex problem both to
workers in the field of pure nutrition and
to fish culturists. Consequently, there has been
a lack of extensive research, as indicated by the
scarcity of reports in the literature, on the nu-
trition of fishes other than trout. Most of the
studies in the past have dealt with the relation-
ship between various combinations of different
amounts of natural foods and their effects on the
growth rate of fishes. Early studies provided no
information about the chemical components
necessary for normal growth. Embody & Gordon
(1924) reported on the natural and artificial
food of trout. More recent work by Wolf (1951) ,
Halver & Coates (1957), Halver (1957) and
Coates & Halver (1958) has indicated some
success in composing synthetic diets based on
the requirements of Embody and Gordon.
The varied composition of natural foods, with
necessary growth factors and trace elements,
makes it unlikely that fishes in nature, both fresh
and salt water, are often afflicted with dietary
deficiencies. Comfort (1956) stated that the
weight of evidence suggested that senescene in
the wild is rare but not unknown.
On the other hand, it has been known for a
long time that fishes in captivity, mainly those
raised by government-controlled hatcheries, are
susceptible to various pathological conditions
caused in many cases by the use of synthetic
diets (Wolf, 1951). The use of synthetic diets
*A dissertation in the Department of Biology sub-
mitted to the Faculty of the Graduate School of Arts
and Science in partial fulfillment of the requirements
for the degree of Doctor of Philosophy at New York
University.
lies in the importance of the artificial breeding
of these fish in large numbers at low cost. Very
little work has been done on marine fishes, fresh-
water fishes of no interest to anglers and on
“tropical fish” found in aquaria. Although syn-
thetic diets for salmon (Halver, 1957) and trout
(Wolf, 1951) have been reported, these large
cold water salmonoid fishes do not lend them-
selves readily to laboratory experimentation un-
der controlled conditions.
The use of vitamin antimetabolites is a con-
venient method to study vitamin deficiencies in
an organism where a satisfactory synthetic diet
has not been formulated. Groups of fish were
also reared under axenic conditions, thus im-
proving environmental control to a considerable
degree. A further objective of this study was the
effect of the antivitamins on the growth and
mortality of the guppy (Lebistes reticulatus).
There has been no report in the English literature
of a normal growth curve (weight plotted against
time) for any warm water “tropical fish.” Such
growth curves, including one plotting length
against time, and growth curves resulting from
the effects of the analogs were determined in
this study.
Some of the basic concepts of the action of
antimetabolites stem back to the time of Paul
Ehrlich (1907) who coined the term “chemo-
therapy”. The idea of competitive inhibition had
its roots in the work of Michaelis & Menten
(1913) and later (1927) in the work of Quastel
& Wooldridge who showed the competitive
inhibition of succinic dehydrogenase by malonic
acid, a structural analog of succinic acid. Fol-
lowing the report of Woods (1940) on the action
of sulfanilamide, Fildes (1940) proposed a ra-
tional approach to chemotherapy by the use of
77
78
Zoologica: New York Zoological Society
[51: 7
structural analogs of known essential metabo-
lites.
Thiamine is required by most living organ-
isms. Phillips, et ah (1946) produced the first
critical work on fishes in establishing the thia-
mine requirement of trout. The presence of a
thiamine-splitting enzyme in nature was first
reported to be found in carp viscera which were
fed to foxes (Green & Shillinger, 1936; Green,
Evans & Carlson, 1937). These foxes developed
a typical polyneuritic sympton that was referred
to as “Chastek paralysis.” This condition was
relieved by the administration of thiamine.
Wooley (1941) found that carp tissue contained
a thiamine-splitting enzyme that was thermo-
labile and nondialyzable. Wolf (1942), while
working on trout, noted thiamine deficiency
symptoms when diets containing raw fish were
used. This thiamine-destroying principle was
subsequently called thiaminase. Deutsch & Has-
ler (1943) studied the distribution of thiaminase
among freshwater fishes while Yudkin (1945)
investigated the occurrence of thiaminase in ma-
rine teleosts. Thiaminase from whole carp and
fractions elicited deficiency in chicks (Spitzer,
Coombes, Elvehjem & Wesnicky, 1941), and
feeding on carp eggs caused avitaminosis and
death to the catfish Schilbeodes mollis (Harring-
ton, 1954).
The bracken fern Pteris aquilina appears to
be another source of a thiamine-destroying prin-
ciple. Horses and cattle which had consumed
large amounts of bracken fern became ill with
“fern poisoning” (Weswig, Freed & Haag, 1946).
Recent reports indicate a mass poisoning of
calves by Pteris aquilina (Gregorovic, Skusek &
Senk, 1962).
Deoxypyridoxine effects have been studied in
the chick (Ott, 1946), chick embryo (Cravens
& Snell, 1949; Karnofsky, et ah, 1950), rat and
mouse (Umbreit, 1955). The work on fishes
with the metabolite pyridoxine has been less crit-
ical than that on higher vertebrates. In trout, its
absence, plus the absence of riboflavin and pant-
othenic acid, were collectively believed to cause
anemia (Tunison et ah, 1944). McLaren, et al.,
( 1947) working with purified rations to produce
pyridoxine deficiency on the trout, Salmo gaird-
neri, reported nervous disorders, epileptiform
fits and light spots on the liver. Halver (1953)
working with vitamin-free basal rations on the
Chinook salmon, Onchorhynchus tshawytscha,
reported pyridoxine deficiency symptoms such as
nervous disorders, epileptiform fits, hyperirrita-
bility, ataxia, anemia, anorexia, edema of the
peritoneal cavity, colorless serous fluid, spastic
convulsions, blue coloration on back, rapid and
gasping breathing, flexing of the opercles and
post mortem rigor mortis occurring rapidly.
Biotin has been referred to as the “anti egg-
white injury factor” (Lease & Parsons, 1934)
and is found almost universally in plants and
animals. A deficiency caused by feeding egg
white containing avidin to rats elicited derma-
titis, retarded growth, loss of hair and muscular
control (Martin, 1951). The first antimetabolite
of biotin synthesized was desthiobiothin which
was active on Lactobacillus casei (duVigneaud,
1942). Phillips, et ah, (1947) established the
dietary need for biotin in trout. Phillips, Brock-
way & Rodgers (1950) reported that a dietary
biotin deficiency in brown trout caused a condi-
tion characterized by a bluish film covering the
body. This coating eventually sloughed off giv-
ing the trout a patched appearance. The disease
was referred to as “blue-slime” or “slime-patch.”
McLaren, et ah, (1947) reported that biotin
deficiency caused anorexia and retarded growth
in trout and Halver (1953) noted that a defi-
ciency in salmon caused a dark coloration, mus-
cle atrophy, spastic convulsions and fragmenta-
tion of erythrocytes.
The characteristic syndrome of ascorbic acid
(vitamin C) deficiency or scurvy has been recog-
nized for centuries. Woolley & Krampitz ( 1943)
reported on the first ascorbic acid analog, gluco-
ascorbic acid. They produced a syndrome in rats
and mice induced by glucoascorbic acid some-
what paralleling that of scurvy, even though
rats and mice do not ordinarily require this meta-
bolite. However, Wooley (1944) soon demon-
strated the antivitamin action of glucoascorbic
acid on guinea pigs, which do require ascorbic
acid. In the field of fish nutrition, McLaren, et
ah, (1947) reported nutritional deficiency symp-
toms in trout, while Wolf (1951) and Halver
( 1953) reported that ascorbic acid was not nec-
essary in trout and in salmon, respectively.
Materials and Methods
The following antimetabolites were used:
oxythiamine (OBi), in which the amino group
in position 4 of the pyridine moiety of thiamine
was replaced by a hydroxyl group, (Text-fig. 1),
(Bergel & Todd, 1937) ; neopyrithiamine (NPT)
or purified pyrithiamine, formed by the displace-
ment of the thiozole nucleus with a pyrimidine
ring, (Text-fig. 1) (Wilson & Harris, 1949);ther-
molabile factor (LF) and thermostabile factor
(SF), extracted from the fern Pteris aquilina by
cold acetone, (Fujita, 1954) ; aqueous labile fac-
tor (ALF) and aqueous stabile factor (ASF) ex-
tracted from P. aquilina; desthiobiotin (DB), in
which the tetrahydrothiophene ring of biotin was
1966]
Pappus: Lebistes reticulatus
79
split and the sulfur atom eliminated, (duVig-
neaud, 1942) ; deoxypyridoxine ( DBe) , in which
there was a replacement of the hydroxymethyl
group of pyridoxine by a methyl group at posi-
tion 4, (Ott, 1946), and glucoascorbic acid
(GAA), a 7 carbon analog of ascorbic acid
(Woolley & Krampitz, 1943).
Newborn guppies ( Lebistes reticulatus) of un-
known genetic stock and raised in the investi-
gator's laboratory were used throughout the ex-
periment. Single litters were chosen for the
procedure outlined.
Non Axenic Conditions
The young fish in groups of 10 were placed
in 200ml of “conditioned” boiled aquarium
water of pH 7.2 at a temperature of 23.0°C.
“Conditioned” aquarium water is water in which
fish previously had lived (Allee, 1938). Round,
stacked culture dishes were used as containers
in the non-axenic controls and experimental
groups with the added antimetabolite. The ana-
logs were added directly to the water. The fish
were measured with a caliper, weighed (wet)
and transferred weekly to water with fresh con-
centrations of antimetabolites.
Preparation of Extracts and Diet
The concentrations in micrograms of anti-
metabolites employed were as follows: 1, 2, 3,
4, 5, 10, 20, 40, oxythiamine; 5, 10, 25, 50, 100,
pyrithiamine; 50, 100, 200, desthiobiotin; 5, 50,
100, deoxypyridoxine; 50, 100, 250, glucoascor-
bic acid; and in percent solution: 1, 2, 5, 10, 15,
aqueous non-heated fern extract (ALF), (50gm
triturated leaves per liter of distilled water and
filtered after standing for 30 minutes); 1, 2, 5,
10, 15, aqueous heated fern extract (ASF),
(heated to boiling for 10 minutes); and in mg
percent: 0.5, 5, 10, 40, of cold acetone extracted
precipitate from fern (LF); and 5, 10, 20, 40,
of powder from evaporated fern filtrate (SF).
The analogs were obtained from commercial and
private sources, while the fern extract (LF and
SF) were prepared by the method of Fujita
(1954).
The experiments were conducted over a per-
iod of 12 weeks so that sufficient time would be
available for sexual differentiation.
The diet consisted of a modification of the
liver-cereal wet food and standard dried food
of Gordon ( 1950) . The fish were fed three times
a week.
Axenic Technique
The procedures previously outlined were re-
peated with modification, using axenic fish as
follows :
Gravid females in groups of two were placed
in water for 48 hours containing 50mg of chlor-
tetracycline HC1 per liter as a preparation for
obtaining germfree young. Wendt (1956) dem-
onstrated that 5.0mg% chlortetracycline HC1
produced no statistical significance on the
weights and lengths of guppies as compared to
that of controls at the 15-week stage. During
the 48 hours of preparation time, no food was
administered in order to clear the intestinal tract,
since it had been previously reported that fasting
fish normally do not have bacteria in their in-
testinal tract and that the organisms are intro-
duced only at the time of food intake (Margolis.
1953). The fish were placed in chlorobutanol
anesthesia solution until complete immobiliza-
tion was observed, and this was followed by a
three-minute immersion in tincture of merthio-
late. They were passed through two washings of
70 percent alcohol and placed on sterile gauze.
With sterile instruments, an incision was made
between the anal opening and anal fin at about
a 45-degree angle, tangentially to the peritoneal
cavity. The peritoneum was thus left temporarily
intact and the operating area remained sterile.
An opening was then made in the silvery peri-
toneum and the ovarian membrane was rup-
tured. A gradual pressure on the branchial re-
gion of the fish caused the entire clump of
embryos to protrude. The embryos were then
dropped in sterile distilled conditioned water in
a Syracuse crystal placed in a petri dish. The
water contained salts in the following concen-
trations: 0.8% NaCl; 0.024% CaCh 0.042%
KC1; 0.1% NaHCOs. In order to prepare this
medium, the salts were dissolved in distilled
water and guppies were placed in it for 24 hours.
200ml of this “conditioned fish saline” were
placed in 500ml cotton-stoppered flasks and
autoclaved. The embryos obtained by sterile
technique were placed in this conditioned fish
saline in groups of 10. Autoclaved fish food was
introduced three times a week. Oxythiamine,
pyrithiamine, desthiobiotin, glucoascorbic acid
and deoxypyridoxine in the minimum concen-
trations were passed through a Seitz bacterial
filter and introduced into the sterile cultures.
Every 24 hours after feeding, one ml of water
was removed and introduced into an agar plate
to test sterility.
In order to establish the effective dosage for
each analog in the non-axenic groups, prelimi-
nary experiments of the immersion type were
conducted in which the concentration of the ana-
log was increased until atypical behavior of the
fish was observed or the maximum solubility
point of the analog was reached.
80
Zoologica: New York Zoological Society
[51:7
Reversal
One of the criteria for confirming the status
of a substance as an antimetabolite in an organ-
ism has been the ability of the respective meta-
bolite to reverse the effects of the analog. Be-
cause of a significant difference in weight and
length between male and female guppies, in the
first reversal experiment only adult male guppies
in groups of six were tested. Fish in groups of
three were fed on alternate days 50mg of liver-
cereal food which also contained 10% analog
by weight. This was necessary in order to in-
activate the vitamin in the food, so that contin-
ued feeding would not introduce an excess of
metabolite which would raise the required
amount of antimetabolite necessary to cause in-
hibition.
When a 50% mortality of the fish occurred,
the respective metabolite was added to the solu-
tion. The average weight of the groups of fish
was recorded and the survivors were weighed
in four days.
Reversal in young immature fish was demon-
strated in the following manner:
Week-old guppies in groups of 12 were placed
in 200ml of conditioned water. In addition to a
control group, there were five groups, each of
which contained antimetabolites in a solution
containing oxythiamine, 40/xg; pyrithiamine,
100/xg; aqueous non-heated fern extract ( ALF) ,
1%; acetone extracted fern (SF) 40mg%; and
deoxypyridoxine, lOOftg. Every two days each
group was fed 50mg of liver-cereal wet food,
containing 10% of the respective antimetabolite
used in solution. The purpose of the last pro-
cedure was to inactivate the natural vitamins in
the food by the 10% antimetabolite portion,
thus allowing the antimetabolite in solution to
act directly upon the fish. When a minimum of
Vi mortality was reached for each group the
reversal phase of the experiment was initiated.
Corresponding metabolite was added to each
group at an equivalent or greater concentration
than the original concentration of the antimeta-
bolite. Subsequent feedings of 50mg of liver-
cereal wet food were continued on alternate days
but without the addition of any metabolite.
The average weight of each group was deter-
mined at the onset of the experiment and, there-
after, at seven-day intervals. The data in Text-
figure 2 were carried up to seven weeks growth
since it is possible that the length and especially
the weight of the fish may be unduly influenced
by the male differentiating at seven weeks. This
results in a relative stabilization of male weights
while female weights will continue to rise. The
presence of a greater number of females than
males after seven weeks of growth results in a
sharper growth curve.
Results
Normal Growth
Growth was measured as the average mean
weight and average mean standard length (snout
to caudal peduncle). The data indicate that the
weight rose from 8.7 mg at the end of the first
week to 18.5 mg by the end of the 7th week
(Text-fig. 2, A & D). A marked increase in
weight was observed between the first and second
weeks. The weight increase after the second
week and up to the seventh week was gradual.
The rate of growth measured in terms of length
did not show a gradual weekly increase but was
variable and indicated the lower part of a sig-
moid curve. At seven weeks of age, sexual differ-
entiation of the males was observed, character-
ized by the development of the typical male
pigmentation and gonopodium. Sexual different-
iation of the females occurred by the 12th week.
Oxythiamine
Oxythiamine was effective in eliciting thia-
mine deficiency symptoms in a minimal concen-
tration of 1 /j.g, resulting in a survival period of
16.2 days. The survival period at a maximum
concentration of 40 /x g was reduced to 3.7 days.
However, no effects were observed before three
days, regardless of the concentration of analog
used. The effects of oxythiamine on the weight
and length of the guppy indicate a weight increase
up to the fourth week followed by a sharp drop in
the fifth week (Text-fig. 2A). The effect on length
was minimal. The onset of the deficiency syn-
drome similar to that induced by thiamine nutri-
tional deficiency as described by Halver (1953,
1957) was characterized by a general loss of
equilibrium. The fish swam or remained motion-
less on their sides. Eventually they swam in a
spiral fashion and often with their heads on the
bottom of the container and their bodies vertical.
At times, they remained motionless near the sur-
face or close to the bottom. General anorexia
was observed after 24 hours. The critical point
of the deficiency syndrome was the onset of the
spastic convulsive swimming movements, ataxia
and rapid flexing of the opercles, followed by
periods when the fish was inverted on the bottom
with only the pectoral fins in slight motion.
Death occurred within 24 hours of the latter
symptoms. Oxythiamine appeared to be a more
powerful displacer of thiamine than was pyrithi-
amine, the next analog tested, since a 10 /xg con-
centration of oxythiamine was sufficient to re-
duce the survival time to a minimal range of
1966]
Pappas: Lebistes reticulatus
81
3.9 days, whereas 10 pg of pyrithiamine resulted
in a survival period of 27.4 days.
Pyrithiamine
The effect of this analog on survival indicates
that it is less active than oxythiamine at a similar
concentration (Table 1). However, pyrithia-
mine has a greater effect on the weight and a
comparable effect on the length of the fish when
compared to the effects of oxythiamine (Text-
fig. 2A).
Thiaminase Fern Extract
The acetone extracted thermolabile portion
of the fern extract (LF) elicited no grossly visi-
ble effects resembling thiamine deficiency (Table
1 ) . However, the acetone extracted thermostable
factor (SF) which was the brick red powder
resulting from the vacuum and heat drying of
the supernatant material showed activity (Table
1 ) . The aqueous extractions of the fern demon-
strated that the aqueous labile factor (ALF)
was effective while the aqueous stabile factor
(ASF) was not effective in survival (Table 1).
Similar effects were noted on the weight of the
fish (Text-fig. 2C). Therefore, SF and ALF
showed activity while LF and ASF showed no
activity.
Desthiobiotin
Desthiobiotin had no adverse effects on the
growth of the guppy raised in non-axenic condi-
tion ( Table 1 ) . There was no evidence of anorexia
or blue slime-patch disease. However, when new-
born guppies were axenically raised, desthiobio-
tin proved to be an active antagonist. At 18 days
from the start of the experiment, a generalized
ataxia was observed, in addition to a darker body
coloration. However, there was no sloughing off
of any part of the epidermis as is the case in blue
slime -patch disease of trout. By 21 days, no fish
had survived the experimental treatment.
Deoxypyridoxine
Deoxypyridoxine was an active analog of pyri-
doxine in the guppy at concentrations of 100 pg
(Table 1). In comparing this analog with the
others used, it demonstrated a greater effect on
inhibiting weight increase, with the result that
there was no significant increase in the first six
weeks (Text-fig. 2B). In addition, ataxia, ano-
rexia, “yawning” of the mouth and flexing of the
opercles were observed.
Glucoascorbic Acid
In a maximum concentration of 250- pg of
glucoascorbic acid, no abnormal indications of
growth, appetite or mortality were observed in
the fish raised in non-axenic culture. The fish
raised axenically showed retardation of growth,
generalized edema and a high mortality with no
survivors by the sixth week (Text-fig. 2D).
Reversal
The reversal experiment with adult fish indi-
cated that oxythiamine was more active than
pyrithiamine, since oxythiamine caused 50%
mortality in fish in a shorter time and in a lesser
concentration (Table 2, Text-fig. 2E). When
thiamine was added on the 10th day, the per cent
mortality decreased and the weight increased. A
reversal by the normal metabolite was also noted
with pyrithiamine, fern extracts ALF and SF and
deoxypyridoxine (Table 3, Text-fig. 2, F, G & H).
'N — CNH HCI
/<
CHS’C (7-CH.-NI
3 ' " |Vc
C—CHjCHjOH
CH,CH,0H
CHjC C-CH.-N
N — C*H Cl H
THIAMINE
N— C0H
/*
|V— s
N— CH Cl H
OXYTHIAMINE
N=CNH,HBr
’ ; ch, ch,ch,
CH£ C-CH,-NC>
h Br
OH
if C
1 I
N— 6
NEOPYRITHIAMINE
Text-fig. 1. Oxythiamine and pyrithiamine, two
analogs of thiamine.
82
Zoologica: New York Zoological Society
[51: 7
TIME IN WEEKS TIME IN WEEKS
PERCENT MORTALITY
Text-fig. 2. A: The effect of oxythiamine (OBi) and pyrithiamine (NPT) on the
weight of Lebistes; B: desthiobiotin (DB), deoxypyridoxine (DB<;) and glucoascorbic
acid (GAA) effects on weight; C: fern labile factor (LF), fern stable factor (SF),
fern aqueous stable factor (ASF) and fern aqueous labile factor (ALF) effects on
weight: D: desthiobiotin (DB), desthiobiotin-axenic culture (DB-AX), glucoascorbic
acid (GAA) and glucoascorbic acid-axenic culture (GAA-AX) effects on length; E:
oxythiamine (OBj) reversal by thiamine and percent mortality; F: pyrithiamine (NPT)
reversal by thiamine; G: fern aqueous labile factor (ALF) reversal by thiamine; H:
deoxypyridoxine (DBr,) reversal by pyridoxine.
1966]
Pappas: Lebistes reticulatus
83
Table 1. The Effect of Analogs on the Survival of the Guppy
(Ten fish used at each concentration.)
Analog
Concentration
Survival in days (30 day period)
Control A
(non-axenic)
30
Control I
(axenic + food)
30
Control II
(axenic no food)
micrograms
6 ±0.211
oxythiamine
1
16.2 ± 3.83
2
17.7 ± 3.46
3
8.3 ± 2.47
4
9.0 ± 3.12
5
11.2 ±2.54
10
3.9 ± 0.74
20
5.1 ± 0.32
40
3.7 ±0.21
pyrithiamine
5
28.1 ± 1.29
10
27.4 ± 1.42
25
21.4 ± 2.56
50
18.0 ± 1.78
100
11.3 ± 1.82
deoxy-
5
28.4 ± 1.60
pyridoxine
50
28.7 ± 1.30
100
19.6 ± 1.43
desthiobiotin
50
30.0
100
30.0
200
28.4 ± 1.60
200 (axenic)
19.1 ±0.32
glucoascorbic
50
30.0
acid
100
30.0
250
30.0
250 (axenic)
per cent
27.2 ± 1.17
aqueous
1
27.3 ± 2.70
labile factor
2
4.2 ±0.36
(ALF)
5
1.0
10
1.0
15
1.0
aqueous
1
30.0
stable factor
2
30.0
(ASF)
5
27.4 ± 2.70
10
30.0
15
mg per cent
30.0
labile factor
0.5
30.0
(LF)
5
28.0 ± 2.00
10
30.0
40
30.0
stable factor
5
28.2 ± 1.80
(SF)
10
25.5 ± 3.02
20
30.0
40
2.6 ± 0.27
time that reversal was started.
84
Zoologica: New York Zoological Society
[51:7
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Table 2. Reversal of Antimetabolites in the Adult Male Guppy (Lebistes reticulatus).
1966]
Pappas: Lebistes reticulatus
85
Table 4. Antimetabolite Syndromes
Analog
Signs of avitaminosis
In Lebistes
In other organisms
oxythiamine Polyneuritic-type symptoms; loss
of equilibrium; ataxia; rolling;
“standing on head;” anorexia;
convulsions and death, survival
time 3-4 days.
pyrithiamine Polyneuritic-type symptoms;
ataxia; loss of equilibrium; tem-
porary immobility; scoliosis; anor-
exia; convulsions and death; sur-
vival time 12-28 days.
aqueous fern Loss of equilibrium, ataxia; poly-
extract (ALF) neuritis; convulsions; death in 24
hours in 2% solution.
aqueous
heated fern
extract (ASF)
fern labile
factor (LF)
fern stable
factor (SF)
desthiobiotin
deoxypri-
doxine
No effect
No effect
Nervous disorders; death in 24
hours in 40mg% concentration.
No evidence of anorexia; de-
creased growth or blue slime-
patch disease, as in trout. In ax-
enic culture, poor growth, anor-
exia, darker body coloration,
ataxia.
Nervous disorders; ataxia; anor-
exia; decreased growth; rapid and
gasping breathing; flexing of oper-
cles; 10% survival at 7 days.
gluco-
ascorbic
acid
No abnormal indication of growth
appetite or mortality in non-axenic
fish. Edema, decline in weight in
axenic culture.
No polyneuritis, but anorexia, weight loss and
death in mice (Soodak and Cerecedo, 1947);
increased blood pyruvate and blood lactate in
rats, depression of thiamine in tissues, increased
thiamine excretion (Frohman and Day, 1949);
retardation of growth, head retraction, convul-
sions and death in the chick (Daniel and Nor-
ris, 1949); local and general edema in chick
embryo (Naber, et a!., 1954); competive in-
hibition in mice (Cerecedo, et al., 1951).
Polyneuritis, anorexia, weight loss and death in
7-8 days in rats and mice (Eusebi and Cerecedo,
1949); polyneuritis and death in chick embryos
(Naber, et al., 1954); normal blood pyruvate
and liver cocarboxylase (Woolley and Merefield,
1952); decrease of total thiamine in muscle,
liver and brain of rat (DeCaro, et al., 1954);
competitive inhibition in bacteria (Woolley and
White, 1943) and in mice (Eusebi and Cerecedo,
1949).
Polyneuritis, reduced blood thiamine, elevated
blood pyruvate in rats (Evans and Evans, 1949);
same in horses (Evans, et al., 1951), but not in
cattle (Evans, et al., 1954).
Factor is labile (Thomas and Walker, 1949:
Evans and Jones, 1952). Factor is stable (Wes-
wig. et al., 1946). More active LF and less active
SF are both present in fern (Fujita, 1954).
Growth factor in yeast (Saccharomyces cerevisae)
and antibiotin factor for Lactobacillus easel
(duVigneaud, 1942); no effect on higher organ-
isms.
Atrophy and degeneration of spleen and thy-
mus in chicks, rats, dogs and monkeys; micro-
cytic anemia and leucopenia in dogs; dryness of
hair, skin sealines , tongue lesions, hyper-irrita-
bility and convulsions of epileptic nature in mon-
keys (Mushett, et al., 1947).
Growth inhibition, diarrhea, multiple hemor-
rhages, but no effect on teeth in rats at 10%
level in food (Woolley and Krampitz, 1943).
Guinea pigs on purified rations and GAA pro-
duced disease that was reversed by ascorbic
acid (Woolley, 1944). Ascorbic acid at similar
10% level caused similar syndrome in rats ex-
cept hemorrhages as did 10% of GAA (Banar-
jee and Elvehjem, 1945).
86
Zoologica: New York Zoological Society
[51: 7
Discussion
In considering the effects of temperature on
the growth of fishes, Brown ( 1957) pointed out
that the slopes of growth curves for fishes may
vary considerably according to the degress of
detail in the information available. When the
growth cycles are “smoothed out” by using an-
nual data for temperate fishes which have annual
growth cycles, curves showing lengths or weights
plotted against age are generally sigmoid. In the
present investigation, such a growth curve was
obtained under controlled laboratory conditions.
There were, however, short periods when the
increase of length was not very great or when
there was an actual decrease in weight only.
There was never any decrease in the length of
the guppy regardless of the experimental pro-
cedure employed. The consistent size of the con-
tainers also enabled reproductible results which
was in agreement with findings of Comfort
(1956) who reported specific maximum sizes of
fish for each size of container and each level of
nutrition. When a fish was transferred from one
size container to a larger, or when fish were re-
moved from a tank population, a new plateau
was reached.
The thiamine analogs, oxythiamine and pyri-
thiamine, both elicited polyneuritic-type symp-
toms in fish, and oxythiamine appeared to be a
more powerful antagonist than pyrithiamine. In
the lower concentrations of oxythiamine, there
was a proportionately larger spread of survival
values than in the higher concentrations. More
time was required for the analog to take effect.
The amount of thiamine in the diet was appar-
ently sufficient to enable the survivors of the
first several days to live for periods beyond the
30-day test period. Since an increase of up to
40 ^g did not elicit the symptoms any sooner
than three days, it is possible that the pre-existing
thiamine retarded the onset of symptoms.
Previous studies on mice and rats (Soodak &
Cerecedo, 1947), and on chicks (Naber, et al.,
1954), have indicated that oxythiamine did not
elicit polyneuritic symptoms and was not as pow-
erful an inhibitor as pyrithiamine. The results
of this investigation indicated that oxythiamine
did elicit polyneuritic-type symptoms in fish and
was, in fact, a more powerful antagonist than
pyrithiamine. Oxythiamine elicited the charac-
teristic symptoms much sooner and at a much
lower concentration than did pyrithiamine.
The differential mode of action of oxythia-
mine and pyrithiamine in mice and rats has been
interpreted to signify that these analogs attack
different systems in the tissues (Wooley & Mere-
field, 1952). It is possible that the signs of avita-
minosis may have been due to an unrecognized
function of thiamine not concerned with cocar-
boxylase or with elevated tissue pyruvate. The
different times that oxythiamine and pyrithia-
mine affected the guppies also indicated their
separate role in their blocking of thiamine. If
the analogs affected a single metabolic pathway
of thiamine, then their action at the minimal
effective concentration under identical condi-
tions would have been simultaneous.
The results from the fern extracts indicated
that there was a thermostabile substance that was
removed by aqueous extraction which was very
effective in producing thiamine deficiency symp-
toms in the guppy. The stable factor was not re-
moved by aqueous extraction. However, cold
acetone did remove the stable factor in the fil-
trate. This stable factor was very active in elicit-
ing deficiency symptoms in the guppy.
The presence of labile and stabile thiamine-
destroying factors in bacteria, ferns, Crustacea
and the viscera of vertebrates presents an inter-
esting situation. Although it has been suggested
that thiaminase may be involved in thiamine syn-
thesis, fish require an external source of this
vitamin, whereas lower organisms may not re-
quire it in the intact molecule. The action or
oxythiamine, pyrithiamine and labile and stable
fern extracts indicated that there may have been
an unrecognized function in synthesis, utilization
or otherwise, of thiamine in fishes and other or-
ganisms. The mechanisms by which polyneuritic
type symptoms have appeared after dietary or
analog induced thiamine deficiency in birds and
mammals, and now by oxythiamine deficiency in
fish, are yet to be described. The natural occur-
rence of antimetabolites may be correlated with
a regulatory or feedback mechanism by which
cells may check the synthesis and the useless
accumulation of excessive amounts of a meta-
bolite. There is also some evidence that thia-
minase may act in bringing together the thiazole
and pyrimidine portions of thiamine (Fujita,
1954) . Rogers (1962) points out that interest in
antithiamines has fluctuated a great deal during
the two decades since pyrithiamine was first
synthesized. The fundamental aspects of thia-
mine biochemistry have been greatly clarified
during the last three or four years, and more
precise and thoughtful studies of antithiamines
should thereby be encouraged. A second stimu-
lus may be expected from the area of nervous
system biochemistry, since thiamine plays an
important but undefined role there. Undoubtedly
the thiamine antagonists will aid in its solution.
1966]
Pappas: Lebistes reticulatus
87
The biotin analog desthiobiotin has shown
competitive inhibition in some microorganisms
while it can be synthesized by others (duVig-
neaud, 1942). This analog has been found to
have no activity in vertebrates under typical
non-axenic conditions. However, the ability of
desthiobiotin to act as a biotin antimetabolite in
guppies under axenic conditions was apparently
associated with the absence of microorganisms.
Phillips, et al., ( 1950) found that in trout raised
on a diet that caused blue slime-patch disease,
the younger fish were much more sensitive to the
absence of biotin, since they required greater
amounts of the vitamin. Trout that survived for
a period of four to eight weeks appeared to re-
cover, since there was apparently enough biotin
available for their decreased requirements. A
similar condition appeared. to be present in this
investigation. The newborn fish under axenic
conditions were much more susceptible to the
analog than were fish of eight weeks of age or
over.
Pyridoxine or vitamin B6 has been shown to
be dependent on protein intake, and, under cir-
cumstances of pyridoxine deficiency in rats, var-
ious aspects of protein synthesis were impaired.
Deoxypyridoxine, the active analog of pyridox-
ine, was found to inhibt growth in the guppy
because of its possible interference with protein
synthesis. Increasing concentrations of anti-
metabolite elicited a proportionately greater de-
crease of growth which indicated that the effects
of deoxypyridoxine were truly antimetabolic and
not toxic.
The literature on the effect of analog induced
vitamin C deficiency on various animals is incon-
sistent. It has been generally known that only
the guinea pig, monkey and man could be in-
duced to show signs of vitamin C deficiency
by employing an ascorbic acid free diet. In
the field of fish nutrition, McLaren, et. al.,
( 1947) reported dietary deficiency effects, while
Wolf (1951) and Halver (1953) reported no
effects on trout and salmon. These contradictory
reports are probably due to the synthesis of
ascorbic acid by the intestinal flora. The guppies
that were raised non-axenically showed normal
growth even though they were subjected to the
maximum analog concentration. This was ap-
parently possible since there may have been
sufficient ascorbic acid synthesized by the intes-
tinal flora. Interestingly enough, antibiotics, such
as aureomycin, decrease the growth rate of the
guppy (Berke, Silver & Kupperman, 1953). The
present demonstration in which glucoascorbic
acid showed activity in the guppy only under
axenic conditions indicated that it could have
acted as an ascorbic acid antimetabolite in the
absence of any bacterial flora.
Summary
The vitamin antimetabolites, oxythiamine,
pyrithiamine, extracts from the fern (Pteris aqui-
lina), deoxypridoxine, desthiobiotin and gluco-
ascorbic acid were tested on the guppy (Lebistes
reticulatus) in non-axenic and axenic conditions.
A characteristic growth pattern, as indicated by
the lower segment of a sigmoid-type curve, in
respect to weight and length, was demonstrated
from the time of birth to 12 weeks of age. Oxy-
thiamine was a more powerful thiamine antago-
nist than pyrithiamine, and both analogs pro-
duced polyneuritic-type symptoms. Atypical
comparative activity of these substances suggests
a different utilization or alternate reaction path-
way for thiamine. An aqueous extracted thermo-
labile and acetone extracted thermostable anti-
thiamine from fern showed reversible thiamine
inhibition. Natural antimetabolites may act in
the synthesis or in the elimination of excessive
amounts of a metabolite. Deoxypyridoxine acted
as a pyridoxine inhibitor. Desthiobiotin and glu-
coascorbic acid were not active antagonists under
non axenic conditions. Under axenic conditions,
these analogs were active antimetabolites indi-
cating that microorganisms are involved in the
synthesis of their respective metabolites. Re-
versal was demonstrated in all active analogs.
Acknowledgments
I wish to acknowledge my indebtedness to Dr.
Ross F. Nigrelli of New York University and
the New York Aquarium for sponsoring this
research and for his invaluable guidance and di-
rection. I also wish to thank S. B. Penick & Co..
New York, for the fern Pteris aquilina from
which the fern extracts were obtained.
Literature Cited
Allee, W. C.
1938. The Social Life of Animals, New York,
Norton: 356-357.
Banerjee, S. & C. A. Elvehjem.
1945. Effect of feeding glucoascorbic acid to
white rats, chicks and guinea pigs. Proc.
Soc. Exper. Biol. & Med. 60: 4-7.
Bergel, F. & A. R. Todd.
1937. Aneurin, part viii. Some analogues of
aneurin. J. Chem. Soc.: 1504-1509.
Berke, P., A. M. Silver & H. S. Kupperman.
1953. Effect of aureomycin upon growth and
maturation of Lebistes reticulatus. Proc.
Soc. Exper. Biol. & Med. 84: 32-34.
88
Zoologica: New York Zoological Society
[51: 7
Brown, M. E.
1957. Experimental studies on growth. Cited in:
Brown, M. E., The Physiology of Fishes,
New York Academic Press: 361-401.
Cerecedo, L. R., M. Soodak & A. J. Eusebi.
1951. Studies on thiamine analogues I. Experi-
ments//! vivo. J. Biol. Chem. 189: 293-299.
Coates, J. A. & J. E. Halver.
1958. Water soluble vitamin requirements of
silver salmon. Spec. Sci. Rpts., Fisheries
U.S. Fish and Wildlife Serv.), No. 281:
1-9.
Comfort, A.
1956. The Biology of Senescence, New York,
Rinehart and Co., Inc.: 68, 72-75, 108.
Cravens, W. W. & E. E. Snell.
1949. Effects of deoxypyridoxine and vitamin Bo
on development of the chick embryo. Proc.
Soc. Exper. Biol. & Med., 71 : 73-76.
Daniel, L. J. & L. C. Norris.
1949. Effect of oxythiamine on the growth of
chicks. Proc. Soc. Exper. Biol. & Med. 72:
165-169.
De Carlo, L., G. Rindi & E. Grana.
1954. Metabolic effects of neopyrithiamine and
the aneurin contents in the tissues of the
rat. Experimentia. 10: 140-141.
Deutsch, H. F. & A. D. Hasler.
1943. Distribution of a vitamin Bt destructive
enzyme in fish. Proc. Soc. Exper. Biol. &
Med. 53: 63-65.
DUVlGNEAUD, V., J. M. SPANGLER, D. BURK, C. J.
Kensler, K. Sugiura & C. P. Rhoads.
1942. Precarcinogenic effect of biotin in butter
yellow tumor formation. Science 95: 174-
176.
Ehrlich, P.
1907. Cited by Marquardt, M., 1951, in: Paul
Ehrlich, New York, Schuman: 118-119.
Embody, G. L. & M. Gordon.
1924. A comparative study of natural and arti-
ficial foods of brook trout. Trans. Amer.
Fish. Soc., 54: 185-200.
Eusebi, A. J. & L. R. Cerecedo.
Antithiamine effect of oxythiamine neo-
pyrythiamine. A comparative study. Sci-
ence, 110-162.
Evans, E. T. R., W. C. Evans & H. E. Roberts.
1951. Studies on bracken fern poisoning in the
horse. Brit. Vet. Jour., 107: (9): 364-371.
Evans, W. C. & E. T. R. Evans.
1949. Studies on the biochemistry of pasture
plants. The effects of the inclusion of
bracken Pteris aquilina in the diet of rats
and the problem of bracken poisoning of
farm animals. Brit. Vet. Jour., 105 (6):
175.
Evans, W. C., N. R. Jones & R. A. Evans.
1950. The mechanism of antianeurin activity of
bracken Pteris aquilina. Biochem. J. 46:
(5): xxxviii-xxxix.
Fildes, P.
1940. A rational approach to research in chemo-
therapy. Lancet, I.: 955-957.
Frohman, C. E. & H G. Day.
1949. Effect of oxythiamine and pyruvatelactate
relations and the excretion of thiamine in
rats. J. Bio. Chem. 180: 92-98.
Fujita, A.
1954. Thiaminase. Adv. Enzym. 15: 389/421.
Gordon, M.
1950. Fishes as laboratory animals. Cited by
Farris, E. J. (ed.) in The Care and Breed-
ing of Laboratory Animals, New York,
John Wiley & Sons: 345-449.
Gregorovic, V., F. Skusek & L. Senk.
1962. Eagle brake ( Pteris aquilina ): The cause
of mass poisoning on large scale feeding
of calves. In: Internationale Tagung uber
Rinderkrankheiten, 1962. (International
congress on cattle illness, 1962). Wiener
Tierarztl. Monatsschrift. 49 (12): 975-
976.
Green, R. G., C. A. Evans & W. E. Carlson.
1937. Chastek paralysis. Minn. Wild. Dis. In-
vest., 3: 172.
Green, R. G. & J. E. Shillinger.
1936. Chastek paralysis— a new disease of foxes.
Minn. Wild. Dis. Invest., 2: 106.
Halver, J. E.
1953. Fish diseases and nutrition. Trans. Am.
Fish. Soc. 83: 254-261.
1957. Nutrition of salmonoid fishes. III. Water
soluble vitamin requirements of chinook
salmon. J. Nutrition 62: 225-243.
Halver, J. E. & J. A. Coates.
1957. A vitamin test diet for long term feeding
studies. Prog. Fish. Cult., 79 (3) : 112-118.
Harrington, R. W., Jr.
1954. Contrasting susceptibilities of two fish spe-
cies to a diet destructive to vitamin Bi.
Jour. Fish. Res. Bd., Canada, 11 (5): 529-
534.
Karnofsky, D. A., C. C. Stock, L. P. Ridgeway &
P. A. Patterson.
1950. The toxicity of vitamin Bq, 4-deoxypridox-
ine and 4-methoxymethylpyridoxine, alone
1966]
Pappas: Lebistes reticulatus
89
and in combination to the chick embryo.
J. Biol. Chem. 182 : 471-478.
Lease, J. G. & H. T. Parsons.
1934. The relationship of dermatitis in chicks to
lack of vitamin B2 and to dietary egg
white. Biochem. J., 28: 2109-2115.
McLaren, B. A., E. Keller, D. J. O’Donnell &
C. A. Elvehjem.
1947. Nutrition of rainbow trout. I. Vitamin re-
quirements Arch. Biochem. 15: 169-177.
Margolis, L.
1953. The effect of fasting on the bacteriological
flora of the intestine of fish. J. Fish. Res.
Bd. Can., 10 (2): 62-63.
Martin, G. J.
1951. Biological Antagonism. Phila. Pa., Blakis-
ton Co.
Michaelis, L. & M. L. Menten.
1913. Die Kinetik der Invertinwirkung. Bio-
chem. Zeitschrift., 49: 333-369.
Mushett, C. W., R. B. Stebbins & M. N. Barton.
1947. Studies on the pathologic effects produced
by analogues of pyridoxine. Trans. N. Y.
Acad. Sci., 9: 291-296.
Naber, E. C., W. W. Cravens, C. A. Baumann &
H. H. Bird.
1954. The effect of thiamine analogs on em-
bryonic development of the chick. J. Nu-
trition, 54: 579-591.
Ott, W. H.
1946. Antipyrydoxine activity of 2, 4-dimethyl-
3-hydroxy-5-hydroxymethylpyridine in the
chick. Proc. Soc. Exper. Biol. & Med., 61 :
125-127.
Phillips, A. M., D. R. Brockway, E. O. Rodgers,
M. W. Sullivan, B. Cook & J. Chipman.
1946. The nutrition of trout. Cortland Hatchery
Rep. (15) Fish. Res. Bull. 9, N.Y.S. Cons.
Dept., Albany, N. Y. 1-21.
Phillips, A. M., D. R. Brockway, E. O. Rogers,
R. I. Robertson, H. Goodell, J. A. Thompson
& H. Willoughby.
1947. The nutrition of trout. Cortland Hatchery
Rep. (16), Fish. Res. Bull. 10, N.Y.S.
Cons. Dept. Albany, N. Y. 1-35.
Phillips, A. M., D. R. Brockway & E. O. Rodgers.
1950. Biotin and brown trout: The tale of a vita-
min. Prog. Fish Cult. 12 (2): 67-71.
Quastel, J. H. & W. R. Wooldridge.
1927. Experiments on bacteria in relation to the
mechanism of enzyme action. Biochem. J.
21: 1224-1251.
Rogers, E. F.
1962. Thiamine antagonists, In: Unsolved prob-
lems of thiamine. Annals N. Y. Acad.
Sci. 98, art. 2: 412-429.
Soodak, M. & L. Cerecedo.
1947. The effect of oxythiamine and some oxy-
thiamine derivatives on mice. Fed. Proc.,
6: 293.
Spitzer, E. H., C. A. Coombes, C. A. Elvehjem &
W. Wesnicky.
1941. Inactivation of vitamin Bi by raw fish.
Proc. Soc. Exper. Biol. & Med., 48: 376-
379.
Thomas, B. & H. F. Walker.
1949. Inactivation of thiamine by bracken
Pteris aquilina. J. Soc. Chem. Ind.
(London) 68: 6-9.
Tunison, A. V., A. M. Phillips, H. B. Shaffer,
J. M. Maxwell, D. R. Brockway & C. M.
McCay.
1944. The nutrition of trout. Cortland Hatchery
Rep. (13) Fish. Res. Bull. 6, N.Y.S. Cons.
Dept., Albany, N.Y., 1-21.
Umbreit, W. W.
1955. Vitamin Bq antagonists. Amer. J. Clin.
Nutr. 3 (4): 291-297.
Wendt, G. F.
1956. (unpublished) The influence of various
antibiotics on normal growth and devel-
opment of Lebistes reticulatus. M. S.
thesis. New York University.
Weswig, R. J„ A. M. Freed & J. R. Haag.
1946. Antithiamine activity of plant materials.
J. Biol. Chem., 165: 737-738.
Wilson, A. N. & S. A. Harris.
1949. Synthesis and properties of neo-pyrithi-
amine salts. I. Amer. Chem. Soc., 71:
2231-2233.
Wolf, L. E.
1942. A Vitamin deficiency produced by diets
containing raw fish. Fish. Res. Bull (2) : 1,
N.Y.S. Cons. Dept., Albany, N. Y., 1-15.
1959. Diet experiments with trout. Prog. Fish.
Cult., 13 (1): 17-24.
WOOLEY, D. W
1941. Destruction of thiamine by a substance in
certain fish. J. Biol. Chem. 141: 997-998.
1944. Production of a scurvy-like condition of
guinea pigs with glucoascorbic acid, and
its prevention with ascorbic acid. Fed.
Proc. 3: 97.
90
Zoologica: New York Zoological Society
[51: 7
Wooley, D. W. & L. O. Krampitz.
1943. Production of a scurvy-like condition by
feeding of a compound structurally re-
lated to ascorbic acid. J. Exper. Med., 78:
333-339.
Wooley, D. W. & R. B. Merrifield.
1952. Evidence for a metabolic function of thi-
amine not mediated through cocarboxy-
lase. Fed. Proc., 11: 458-459.
Wooley, D. W. & A. C. G. White.
1943. Production of thiamine deficiency disease
by feeding of a pyridine analogue of thi-
amine. J. Biol. Chem. 149: 285-289.
Yudkin, W. H.
1942. Occurrence of thiaminase in marine tele-
osts. Proc. Soc. Exper. Biol. & Med. 60:
268-269.
X
ZOOLOGIC A
SCIENTIFIC CONTRIBUTIONS OF THE
NEW YORK ZOOLOGICAL SOCIETY
VOLUME 51 • ISSUE 3 • FALL, 1966
PUBLISHED BY THE SOCIETY
The ZOOLOGICAL PARK, New York
Contents
PAGE
8. A Digenetic Trematode, Parahaplometroides basiliscae Thatcher, 1963,
from the Mouth of the Crested Lizard, Basiliscus basiliscus. By Horace W.
Stunkard & Charles P. Gandal. Plates I & II 91
9. Enzootics in the New York Aquarium Caused by Cryptocaryon irritans
Brown, 195 1 ( =lchthyophthirius marinus Sikama, 1961 ), a Histophagous
Ciliate in the Skin, Eyes and Gills of Marine Fishes. By Ross F. Nigrelli &
George D. Ruggieri, S J. Plates I-VII 97
10. Analysis of Underwater Odobenus Calls with Remarks on the Develop-
ment and Function of the Pharyngeal Pouches. By William E. Schevill,
William A. Watkins & Carleton Ray. Plates I-V; Phonograph Disk. . . 103
Zoologica is published quarterly by the New York Zoological Society at the New York
Zoological Park, Bronx Park, Bronx, N. Y. 10460, and manuscripts, subscriptions, orders for back
issues and changes of address should be sent to that address. Subscription rates: $6.00 per year;
single numbers, $1.50, unless otherwise stated in the Society's catalog of publications. Second-class
postage paid at Bronx, N. Y.
Published November 29, 1966
8
A Digenetic Trematode, Parahaplometroides basiliscae
Thatcher, 1963, from the Mouth of the Crested Lizard,
Basiliscus basiliscus 1 2
Horace W. Stunkard- & Charles P. Gandal3
(Plates I & II)
Introduction
A SPECIMEN of Basiliscus basiliscus, from
an unknown locality in South America,
. purchased from a commercial dealer, was
received at the New York Zoological Park on
June 24, 1965, and died December 23, 1965. At
autopsy, 18 trematodes were found in the mouth,
firmly attached to the mucosa. While at the Zoo,
the animal had been fed sporadically on crickets,
but no other food was provided. Accordingly, it
is probable that the trematode parasites were
acquired before arrival at the Zoo and presum-
ably while in the wild. The worms are similar to
and probably identical with specimens from
Basiliscus vittatus, described by Thatcher ( 1963)
as Parahaplometroides basiliscae n. g., n. sp. The
specimens of Thatcher are larger and more ex-
tended, and their organs are correspondingly
larger. The differences, however, are not great
and the present specimens may be smaller as a
result of development in a different host or be-
cause the animal may have suffered impaired nu-
trition as a result of captivity. Accordingly, they
are assigned tentatively to the species P. basili-
scae. Representative specimens are deposited in
the Helminthological Collection of the U. S.
National Museum under the number 61,159.
These lizards inhabit an area from northern
South America to tropical Mexico. They are
active arboreal animals that live along the banks
of rivers. Although usually regarded as herbi-
Tnvestigation supported by Grant NSF-GB-3606, con-
tinuation of G-23561.
2Research Associate, The American Museum of Nat-
ural History, New York, 10024.
3Veterinarian, The New York Zoological Park. Bronx,
New York, 10460.
vorous, Ditmars ( 1933) reported that in captiv-
ity they preferred meal worms and caterpillars
to berries.
The worms ( Fig. 1 ) were fixed without flatten-
ing and preserved in formalin. Specimens stained
with paracarmine and others with haematoxylin
were prepared as whole mounts and others were
sectioned serially in transverse or frontal planes.
The sections were stained with haematoxylin
and erythrosin.
Description
All of the specimens are gravid; they are ovate
to pyriform in outline, only slightly flattened,
and with the preacetabular region narrowed and
curved ventrad. They measure from 4 to 6 mm.
long, 1.3 to 2.5 mm. wide and 0.8 to 1.2 mm.
thick. The cuticula is armed with sharp, thickly-
set spines, 0.030 to 0.032 mm. in length and
0.007 mm. wide at the base, which are reduced
posteriorly and may be absent in the posttesticu-
lar area. The cuticula consists of two distinct
layers (Fig. 3), an outer opaque rugose, amor-
phous stratum, 0.015 mm. in thickness, which
stains with haematoxylin, and an inner, clear,
prismatic layer of similar thickness, in which the
lines are at right angles to the surface, and which
appears pinkish in erythrosin-stained sections.
The spines are set in pits on the external surface
of the inner layer.
The acetabulum is situated in the anterior part
of the middle third of the body and measures
0.60 to 0.65 mm. in diameter. The body-wall
consists of well-developed circular, longitudinal
and oblique layers of muscles and the paren-
chyma is relatively compact. The mouth is sub-
terminal, the oral sucker approximately the same
size as the acetabulum. There is a short pre-
91
92
Zoologica: New York Zoological Society
[51:8
pharynx; the pharynx is spherical to cylindrical,
0.35 to 0.38 mm. long, 0.3 to 0.34 mm. wide,
with peri-pharyngeal glandular cells. The esoph-
agus is about as long as the pharynx and, with its
bifid posterior end, is lined with longitudinal
cuticular ribs. The ceca extend posteriad, paral-
lel to and near the lateral edges of the body. They
are lined with high columnar epithelium and ter-
minate near the posterior end of the body. The
excretory pore is terminal; excretory ducts ap-
pear in sections but the pattern was not worked
out.
The testes are situated diagonally in the pos-
terior half of the body. They are almost spheri-
cal, 0.52 to 0.85 mm. in diameter, often longer
in the dorsoventral axis. The posterior testis is
on the left and the anterior testis on the right
side of the body; fields and zones may overlap
or be distinct. Sperm ducts arise from the antero-
dorsal margins of the testes and pass forward,
converging and uniting as they enter the cirrus
sac, dorsal to the acetabulum. The common
sperm duct, after it enters the cirrus sac, ex-
pands to form a much coiled seminal vesicle,
enclosed in prostatic cells, which occupies the
posterior half of the cirrus sac. From the seminal
vesicle, a short duct leads to the thick-walled,
cylindrical, muscular cirrus, which is protusible
and when retracted measures 0.26 to 0.38 mm.
long and 0.15 to 0.22 mm. wide. The cirrus sac
is 0.80 to 1.25 mm. in length and 0.35 to 0.40
mm. in diameter. It is clavate, wider posteriorly,
and curves diagonally forward, dextrad and ven-
trad to open into the common genital atrium
(Fig. 2), situated in the extracecal area of the
right side, at the level of the bifurcation of the
alimentary tract. The cuticula of the cirrus is
not spined.
The ovary is spherical to oval, situated on the
left side, near the dorsal surface, immediately
posterior to the cirrus sac, and partially over-
lapping the acetabulum. It is 0.32 to 0.51 mm.
in diameter, longest in the dorso-ventral axis.
The oviduct arises at the dorsomedian-posterior
face and passes mediad where it receives a short
duct from the seminal receptacle, an oval struc-
ture 0.018 to 0.020 mm. in length and 0.007 to
0.015 mm. in width. The seminal receptacle is
dorsal and slightly posterior to Mehlis’ gland.
Immediately after receiving the duct from the
seminal receptacle, Laurer’s canal branches from
the oviduct and coils dorsally to open at the
surface of the body. After the emergence of
Laurer’s canal, the oviduct receives the duct
from the vitelline receptacle and, following a
strong sphincter, it expands to form the ootype.
All the structures of the area are enclosed in the
cells of Mehlis’ gland. The initial coils of the
uterus are ventral and anterior to the ootype;
they contain young, thin-shelled eggs, embedded
in masses of spermatozoa. The uterus then passes
posteriad and, as the descending limb, extends in
loops and coils on the dorsal side to the posterior
end of the body. The ascending limb courses
forward in a similar manner on the ventral side
of the body to the level of the acetabulum, where
it turns dorsad and unites with the muscular
metraterm. At the level of the anterior testis, the
uterine coils are displaced to the left side of the
body and at the level of the posterior testis the
uterine coils are displaced to the right side. The
descending limb contains young eggs with thin
shells, whereas in the pretesticular area, the as-
cending limb contains dark-colored, thick-shelled
eggs. The posttesticular region is filled with
uterine coils but here the egg-shells are thin,
usually collapsed, and so similar in appearance
that the descending and ascending limbs cannot
be clearly distinguished. The ascending limb
opens into the metraterm at the level of the ovary
and the metraterm and cirrus sac pass forward,
the metraterm dorsally on the right and the cirrus
sac ventrally on the left. Both open into a shallow
atrium which is obliterated when the cirrus is
protruded. The vitelline follicles are spherical to
pyriform, 0.03 to 0.06 mm. in diameter; they are
situated in the middle third of the body, extend-
ing lateral and dorsal to the digestive ceca from
the level of the acetabulum to the level of the
posterior testis. At the ovarian zone, the follicles
extend more mediad and just posterior to the
ovary, ducts from right and left sides unite to
form the vitelline receptacle, from which a duct
passes forward and ventrad to open into the ovi-
duct as previously noted. Mature, hard-shelled
eggs are oval, 0.038 to 0.045 mm. long and 0.018
to 0.020 mm. wide. The eggs are slightly pointed
at the opercular end and are “shouldered,” i.e.,
each has a thickened rim on the shell, into which
the operculum fits. The eggs are embryonated
when passed.
Discussion
Thatcher (1963) compared Parahaplometro-
ides with Haplometroides Odhner (1911), a
genus erected to contain H. buccicola, from the
mouth of Elaps sp. taken in Paraguay. A second
species of Haplometroides, H. rappia, was de-
scribed by Szidat (1932) from the mouth of
Rappia concolor taken in Liberia. Parahaplo-
metroides was assigned to the subfamily Styphlo-
dorinae Dollfus, 1937, whereas Baer & Joyeux
(1961) included Haplometroides in the subfam-
ily Plagiorchiinae Pratt, 1902, The two genera
differ in shape of body, length of ceca, and in the
location of testes and genital pore, but Thatcher
did not compare Parahaplometroides with other
1966]
Stunkard & Gandal: A Digenetic Trematode
93
similar and related genera. It resembles Ocheto-
soma Braun, 1901, and Zeugorchis Stafford,
1905, in extracecal position of the genital pore
but differs from these genera in length of digest-
ive ceca, position of testes, extent of vitellaria,
and in the presence of a seminal receptacle. In
many respects it is similar to Lechriorchis Staf-
ford, 1905, and Dasymetra Nicoll, 1911, but in
those genera the genital pore is intracecal, med-
ian or submedian, there is no seminal receptacle,
and the vitellaria extend along the greater part
of the ceca. It differs from Styphlodora Looss,
1899; Astiotrema Looss, 1900; Glossidiella Tra-
vassos, 1927; Allopharynx Strom, 1928; and
Paurophyllum Byrd, Parker and Reiber, 1940,
in situation of genital pore, position of testes,
extent of vitellaria and in location in the host.
Microderma Mehra, 1931, lacks Laurer’s canal
and seminal receptacle, while Parallelopharynx
Caballero, 1946, differs in tandem arrangement
of testes near the posterior end of the body, short
metraterm, and extensive vitelline follicles. These
and other related genera belong in the group of
plagiorchiid trematodes of reptiles that have
been included by different authors in the sub-
families Plagiorchiinae Pratt, 1902, Astiotre-
matinae Baer, 1924, and Styphlodorinae Dollfus,
1937. The diagnostic characters of genera and
subfamilies are uncertain and familial relations
are disputed.
Historically, Pratt (1902) erected the sub-
family Reniferinae to include Renifer Pratt,
1902, Styphlodora Looss, Astiotrema Looss,
Ochetosoma Braun, and Oistosomum Odhner,
1902. Odhner (1911) raised Reniferinae to fam-
ilial status and recognized that Styphlodora, Pac-
hypsolus Looss, 1901, and Styphlotrema Odhner,
1911, constitute a closely-related group. Baer
( 1924) divided the Reniferidae into three sub-
families: Reniferinae Pratt, Enodiotrematinae n.
subf., and Styphlotrematinae n. subf. He distin-
guished between Reniferidae and Lepodermati-
dae and in the latter family recognized five sub-
families: Lepodermatinae Looss, 1899; Brachy-
coelinae Looss, 1899; and three new subfamilies:
Astiotrematinae, Cymatocarpinae, and Saphe-
dratinae. Baer excluded Styphlodora and left it
unplaced because of the aberrant type of ex-
cretory vesicle. Dollfus (1937) noted that Sty-
phlotrema, not Styphlodora, has the atypical ex-
cretory vesicle and that the name of the sub-
family is Styphlodorinae.
Lepoderma Looss, 1899, was suppressed as
a synonym of Plagiorchis Liihe, 1899, by Braun
(1901) and Ward (1917) changed the name of
the family from Lepodermatidae to Plagiorchi-
idae. Leao (1945) declared that Renifer is iden-
tical with Ochetosoma and he changed the names
of the family and subfamily from Reniferidae
and Reniferinae to Ochetosomatidae and Oche-
tosomatinae. Yamaguti (1958) rejected the
Ochetosomatidae and Ochetosomatinae; instead
he included Ochetosoma (syn. Renifer Pratt;
Neochetosoma Nicoll, 1911, lapsus for Neo-
chetosoma Caballero, 1949; Heterocoelium Tra-
vassos, 1921; Pseudorenifer Allison and Holl,
1937; and Neorenifer Byrd and Denton, 1938)
in the subfamily Styphlodorinae, which with 18
other subfamilies were included in the family
Plagiorchiidae. The subfamily included: Sty-
phlodora Looss (syn. Platymetra Mehra, 1931 ) ;
Dasymetra Nicoll; Eustomos MacCallum, 1921;
Glossidioides Yamaguti, 1958; Glossidium
Looss, 1899; Haplometroides Odhner, 1911;
Lechriorchis Stafford (syn. Mediorima Nicoll,
1914); Leptophyllum Cohn, 1902 (syn. Trav-
trema Pereira, 1929) ; Ochetosoma Braun; Para-
lepoderma Dollfus, 1950; Paurophyllum Byrd,
Parker & Reiber, 1940; Pneumatophilus Ohd-
ner, 1911; Styphlotrema Odhner, and Zeugorchis
Stafford, 1905 (syn. Caudorchis Talbot, 1933;
Plagitura Holl, 1928, partim; Paralechriorchis
Byrd & Denton, 1938).
Baer & Joyeux (1961) recognized the family
Ochetosomatidae and included Ochetosomatinae
and Styphlodorinae as two of six subfamilies.
The subfamily Ochetosomatinae contained the
genera Ochetosoma Braun (syn. Heterocoelium
Travassos; Neochetosoma Caballero; Neorenifer
Byrd and Denton; Pseudorenifer Allison and
Holl; Renifer Pratt); Pneumatophilus Odhner;
Stomatotrema Odhner, lapsus for Stomatrema
Guberlet, 1928; Zeugorchis Stafford (syn. Cau-
dorchis Talbot; Paralechriorchis Byrd and Den-
ton). The subfamily Styphlodorinae included:
Styphlodora Looss (syn. Paurophyllum Byrd
and Denton for Paurophyllum Byrd, Parker and
Reiber, 1940; Platymetra Mehra, 1931); Allo-
pharynx Strom (syn. Megacustis Bennett, Ptya-
sorchis for Ptyasiorchis Mehra); Aptorchis
Nicoll; Glossidiella Travassos; Glossidium Looss
( syn. Glossidioides Yamaguti) \ Parallelopharynx
Caballero, and Spinometra Mehra (syn. Glossi-
metra Mehra) .
In the arrangement of Yamaguti (1958), the
genera Allopharynx, Glossidiella, Parallelophar-
ynx, Glossimetra, and Spinometra were assigned
with others to the subfamily Astiotrematinae
Baer, 1924, in the family Plagiorchiidae. Thus,
the subfamily Astiotrematinae of Yamaguti is
roughly comparable to the subfamily Styphlo-
dorinae of Baer & Joyeux. In the system of Baer
& Joyeux, the subfamily Astiotrematinae disap-
peared and Astiotrema and related genera were
included in the subfamily Plagiorchiinae, family
94
Zoologica: New York Zoological Society
[51:8
Plagiorchiidae. Whether or not the Plagiorchi-
idae and Ochetosomatidae are distinct families
is debatable, since certain genera are assigned
to one or the other. Even the genera are not
clearly delimited; a number have been proposed
and suppressed as identical, but the genus Oche-
tosoma as revised by Dubois & Mahon (1959)
includes species with such diverse morphology
that the unity and integrity of the genus is com-
promised.
The superfamily Plagiorchioidea Dollfus
( 1930) is a multitudinous and widely dispersed
group with representatives in fishes, amphibians,
reptiles, birds and mammals, where they occur
in the digestive, excretory and respiratory or-
gans. These parasites have undergone extensive
modifications from their invasion of diverse hosts
and varied locations, and evaluation of their
taxonomic relations is very difficult. Yamaguti
attempted to relate the parasitic groups with
their hosts, without reference to superfamily,
whereas Baer & Joyeux followed the outline of
La Rue (1957) based on life-cycles and larval
stages as well as morphology of mature speci-
mens. In their arrangement, the Ochetosomati-
dae and Plagiorchiidae were adjacent families in
the Plagiorchioidea, whereas Yamaguti merged
them as a single unit.
Summary
Digenetic trematodes from the mouth of the
crested lizard, Basiliscus basiliscus, are described.
Although somewhat smaller, they are assigned
tentatively to the species Parahaplometroides
basiliscae Thatcher, 1963. The worms manifest
morphological similarity to Styphlodora Looss,
1899; Ochetosoma Braun, 1901, Haplometroides
Odhner, 1911 and other genera of reptilian para-
sites, but the diagnostic features, taxonomic rela-
tions, and subfamilial assignments of these
genera are uncertain. They were included in the
family Plagiorchiidae Ward, 1917 by Yamaguti
( 1958), whereas certain of them were assigned
to the family Ochetosomatidae Leao, 1945 by
Baer and Joyeux (1961).
Literature Cited
Baer, J. G.
1924. Description of a new genus of Lepoder-
matidae (Trematoda) with a systematic
essay on the family. Parasitol., 16:22-31.
Baer, J. G. & Ch. Joyeux
1961. Classe des Trematodes, in Traite de Zo-
ologie, P. P. Grasse, 4:561-677.
Braun, M.
1901. Zur Verstandigung liber die Giiltigkeit
einiger Namen von Fascioliden-Gattun-
gen. Zool. Anz., 24:56-58.
Ditmars, R. L.
1933. Reptiles of the world. Revised edit., The
Macmillan Co., New York.
Dollfus, R. P.
1930. Le point d'aboutissement des canaux col-
lecteurs a la vessie chez les distomes; son
importance au point de vue systematique.
Ann. Parasitol., 8:143-146.
1937. Trematodes de selaciens et de cheloniens.
Bull, comit. d’etudes histor. et sci. l’Afrique
Occident. Frang., 19:399-519.
Dubois, G. & June Mahon
1959. Etude de quelques trematodes nordameri-
cains, suivie d’une revision des genres
Galactosomum Looss, 1899 et Ochetosoma
Braun, 1901. Bull. Soc. Neuchat. Sci. Nat.,
82:191-229.
La Rue, G. R.
1957. The classification of digenetic Trematoda:
a review and a new system. Exper. Para-
sitol., 6:306-344.
Leao, A. T.
1945. Discussao em torno dos generos Ocheto-
soma Braun, 1901 e Renifer Pratt, 1902
(Trematoda). Mem. Instit. Butantan, 18:
67-74.
Odhner, T.
1911. Nordostafrikanische Trematoden, gross-
tenteils vom Weissen Nil. I. Fascioliden.
Results of the Swedish Exped. to the
White Nile, 1901, under the direction of
L. A. Jagerskiold. Uppsala, Part IV, No.
23:1-168.
Pratt, H. S.
1902. Synopsis of North American invertebrates.
XII. The Trematodes. Part II. The Aspido-
cotylea and the Malacocotylea or digene-
tic forms. Amer. Nat., 36:887-910, 925-
979.
SZIDAT, L.
1932. Parasiten aus Liberia und Franzosisch-
Guinea. II. Teil, Trematoden. Zeitschr.
Parasitenk., 4:506-521.
Thatcher, V. E.
1963. The trematodes of the basilisk lizard from
Tabasco, Mexico. An. Instit. Biol., 34:
205-216.
Ward, H. B.
1917. On the structure and classification of North
American parasitic worms. Jour. Para-
sitol., 4:1-11.
Yamaguti, S.
1958. Systema Helminthum. Vol. I. The digen-
etic trematodes of vertebrates. 1575 pp.;
Interscience Publ., Inc., New York.
1966]
Stunkard & Gandal: A Digene tic Trematode
95
EXPLANATION OF PLATES
Plate I
Fig. 1. Parahaplometroides basiliscae, whole
mount, somewhat flattened, ventral view,
showing gross morphology, suckers, diges-
tive system, gonads, vitellaria, genital pore,
cirrus sac, metraterm, and uterine coils
which cover much of the ovary.
Fig. 3. Oblique view, 1.0 mm. in diameter, from
a different specimen, showing section of
the esophagus and its connection with a
digestive cecum, sections of the cirrus sac
and metraterm, with excretory tubules in
the lateral and ventrolateral areas.
Abbreviations
Plate II
Fig. 2. Oblique view, 1.20 mm. in diameter, re-
sulting from ventral curvature of the fore-
body, through the genital pore, showing
sections of the digestive ceca, the genital
atrium and terminal portions of the cirrus
sac and metraterm, and sections of excre-
tory tubules in the lateral areas.
ac— acetabulum
cs— cirrus sac
es— esophagus
dc— digestive cecum
ex— excretory tubule
gp— genital pore
mt— metraterm
ph— pharynx
os— oral sucker
ov— ovary
sv— seminal vesicle
ts— testis
ut— uterus
vt— vitellaria
STUNKARD & GANDAL
PLATE I
A DIGENETIC TREMATODE ( PARAH APLOM ETROI DES BASILISCAE)
THATCHER, 1963, FROM THE MOUTH OF THE CRESTED LIZARD
( BASCILISCUS BASILISCUS )
STUNKARD & GANDAL
PLATE II
P P
FIG. 3
A DIGENETIC TREMATODE ( PARAHAPLOM ETROI DES BASILISCAE)
THATCHER. 1963, FROM THE MOUTH OF THE CRESTED LIZARD
( BASCILISCUS BASILISCUS )
9
Enzootics in the New York Aquarium Caused by Cryptocaryon
irritans Brown, 1951 (= Ichthyophthirius marinns Sikama, 1961), a
Histophagous Ciliate in the Skin, Eyes and Gills of Marine Fishes.
Ross F. Nigrelli & George D. Ruggieri, S.J.
Department of Comparative Pathology,
Osborn Laboratories of Marine Sciences, New York Aquarium
(Plates I-VII)
Introduction
A PARASITIC holotrichous ciliate resembl-
ing Ichthyophthirius multifilis Fouquet,
. the well-known “Ich” of freshwater
fishes, was first reported by Sikama in 1937 from
more than 45 species of marine fishes dying in
aquaria from several localities of the Institute for
Fisheries of the Tokyo Imperial University, es-
pecially in the Aiti Prefecture, Japan. He (1938)
referred to the disease as “Weisspunktchenkrank-
heit,” or “white spot disease” of marine fishes,
suggesting its similarity to the common “Ich.”
However, Sikama (1960, 1961) recognized that
the ciliate differed distinctly from the freshwater
species in body shape, in nuclear features, and
in its specificity for marine fishes. For these and
other reasons he (1961) named the parasite
Ichthyophthirius marinus. However, Sikama
and, more recently, Kudo ( 1966) were unaware
that the ciliate had been named Cryptocaryon
irritans by Eleanor Brown in 1951, based on pre-
liminary description of the ciliate obtained from
marine fishes in the Aquarium of the Zoological
Society of London. A more complete description
of the meganuclear cycle was given by her in
1963. A priori, Ichthyophthirius marinus Si-
kama, 1961, is a synonym of Cryptocaryon irri-
tans Brown, 1951 .
The present contribution deals with observa-
tions on the susceptibility and pathogenesis of
marine fishes in the New York Aquarium to
Cryptocaryon irritans together with additional
information on its life history, morphology and
cytology.
Material and Methods
The parasites were first observed in the New
York Aquarium in 1958, reaching enzootic pro-
portions in 1964. Table 1 lists the susceptible host
species in the Aquarium’s collection for 1964-
1966.
Both skin and gill infected tissues were fixed
in Bouin’s and in 10% neutral formalin; the
sections were stained with Harris’ hematoxylin-
eosin and with Heidenhain’s Iron-hematoxylin
with and without eosin. Freed ciliates were also
fixed in formalin and stained in toto with H-E;
some were allowed to dry on slides and treated
with 2% AgNC>3 and reduced with U-V to dem-
onstrate the silver-line system.
The activity of the motile form, its encystment
and reproduction, was followed continuously
for many hours. For this purpose, the ciliates
were removed by shaking infected gills in sea
water, centrifuged and washed five times with
millipore-filtered sea water. The organisms were
then distributed to several Syracuse dishes with
filtered sea water and observed both in the dishes
and on wet-mount preparations by light, phase
and interference microscopy.
Some of the fish were simultaneously infected
with Oodinium ocellatum, a parasitic dinoflagel-
late to which these fish are also susceptible. These
were present in small numbers in the living
preparations of the ciliates and were used for
comparing time of encystment and division in
both species.
Life History
The life history of Cryptocaryon irritans is
similar in many respects to Ichthyophthirius
multifilis. The stages in the cycle are as follows;
(1) the trophont, or parasitic (feeding) stage,
in the skin and gills (PI. figs. 1-7); (2) the
97
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tomont, or encysted stage off the host in which
reproduction takes place to produce (PL figs.
8-13); (3) tomites, or small, free-swimming,
non-feeding ciliates that eventually infect the
same or other susceptible hosts (PI. fig. 16).
The living trophonts of Cryptocaryon vary in
size from 48 x 27 to 450 x 350 microns. “Older”
individuals are usually filled with numerous,
densely packed granules, obscuring the mega-
nucleus. No contractile vacuoles were noted. In
young parasitic forms, ingested cellular debris
and blood cells are often seen. The ciliates are
highly plastic, changing their shape constantly as
they move about in the skin„and gills of the host
( PI. figs. 1 -3 ) . However, they all tend to assume
a more or less oval shape when forced to become
free-swimming (PI. fig. 2), extending or retract-
ing the buccal end when they encounter other
individuals or pieces of debris (PI. fig. 3). Even-
tually, motility slows down and the cilia are
gradually absorbed, followed by the development
of the cyst membranes (PI. fig. 8).
The factors responsible for the transition of
the trophont to the tomont are not known. This
change, i.e. cessation of active feeding and drop-
ping off the host, is not due to a sudden lowering
of the temperature, a factor that is well known
for lchthyopthirius.
Regardless of size, once the trophont leaves
the host for whatever cause (e.g. death of the
host), the ciliate slowly becomes encysted and
undergoes its reproductive phase. The following
events were observed in washed ciliates main-
tained in filtered sea water in Syracuse dishes and
in wet-mount preparations at room temperature:
10-15% of the ciliates encysted in 4 hours; these
cysts varied in size from 94.5 x 170 microns to
441 x 252 microns. 100% encystment occurred
within 20 hours; during this time Oodiniwn was
in the 4-cell stage (PI. fig. 9). Within 24 hours
all the encysted forms which were uniformly
opaque showed numerous peripheral vacuoles
(PI. fig. 9), similar to those described by Brown
(1963). No obvious changes were noted in the
cysts for the next 24 hours, but Oodinium had
divided to the 32-cell stage. At 110 hours, the
dinoflagellates were free-swimming while some
of the tomonts showed various stages of division.
Division is unequal and polar, which, according
to Brown (1963), may be a form of budding
rather than simple fission (PI. fig. 10) . The polar
cap divides further to form a group of cells (PI.
fig. 11); later division occurs in the residual
mass, eventually giving rise to a number of simi-
lar sized ciliates within the cyst (PI. fig. 12).
In our studies, the tomites started to emerge
from various cysts from the 6th to the 9th day,
with most of them emerging on the 8th day. The
number of tomites produced depends on the size
of the tomont; some of the largest individuals
may form 200 or more free-swimming forms
(PI. fig. 14). Also, the time of emergence is not
related to cyst size. For example, some of the
smallest tomonts, encysted at the same time as
the largest, developed tomites at the same time
or later than the largest individuals.
The fully developed tomites show motility
within the cyst, and appear to emerge from a
small opening (or openings) on one side of the
cyst wall as thin, flattened forms (PI. fig. 13).
In no case was the cyst completely ruptured
naturally, nor was there any evidence of com-
plete cyst dissolution indicative of enzyme action
(PI. fig. 15).
The newly-emerged tomites are pear-shaped
and on the average measure 56.5 x 35 microns.
The buccal membranelles and the meganucleus
with its four distinct spherical bodies are well
developed (PI. fig. 16). The young ciliates at
first swim slowly nearby and then suddenly in-
crease their swimming activity, darting vigor-
ously away from the parent cyst. The evidence
indicates that they are phototropic. The tomites
remain free-swimming for a relatively short per-
iod; no accurate time was determined but it ap-
pears to be less than 24 hours.
Cytology
Trophont (PI. figs. 1-7). The exact number
of kineties could not be determined in our silver
nitrate treated preparations. However, the ele-
ments are parallel, terminating at the oral region
(PI. fig. 4). There is a well-developed buccal
cavity with a protrusible apparatus, the detail
structure of which was not too clear in our pres-
ent preparations. Brown (1963) reports two
membranes in this complex, a large, stiff pro-
trusible membrane on the left wall overlying a
small membrane on the right wall.
Serial sections of stained gill preparations
clearly show the cytological details of the mega-
nucleus in several individuals of various sizes
and were similar to those seen by Brown in prep-
arations stained with Heidenhain’s hematoxylin.
The meganucleus consists of four spherical bod-
ies linked into a U- or crescent-shaped structure
( PI. fig. 5 ) . There is a well-defined nuclear mem-
brane, a network of chromatin, smaller non-
chromatin bodies and numerous densely stain-
ing, basophilic, spherical-shaped bodies in vacu-
ole-like areas (PI. figs. 6 & 7). The number of
these bodies varies with the size of the nucleus,
1966]
Nigrelli & Ruggieri: Enzootics in the New York Aquarium
99
Table 1. New York Aquarium Host List for Cryptocaryon irritans 1964-1966
SCIENTIFIC NAME
COMMON NAME
NUMBER
DEAD
LOCALITY
HOLOCENTRIDAE
Holocentrus ascenionis
Squirrelfish
5
Atlantic
SERRANIDAE
Paralabrax nebulifer
Sand Bass
1
Indo-Pacific
Grammistes sexlineatus
Golden striped Bass
or Grouper
1
Indo-Pacific
LUTIANIDAE
Lutianus griseus
Gray Snapper
1
Atlantic
HAEMULIDAE
Orthopristis chrysopterus
Pigfish
1
Atlantic
Anisotremus virginicus
Porkfish
1
Atlantic
SPARIDAE
Stenostomus chrysops
Northern Porgy
1
Atlantic
SCIAENIDAE
Eques lanceolatus
Ribbonfish
1
Atlantic
POMACENTRIDAE
Dascyllus auranus
White-tailed Puller
1
Indo-Pacific
LABRIDAE
Labroides phthirophagus
Cleaning Wrasse
1
Indo-Pacific
Lachnolaimus maximus
Hogfish
1
Atlantic
CHAETONDONTIDAE
Pomacanthus para
French Angelfish
1
Atlantic
Angelichthys bermudiensis
Bermudian Blue Angelfish
1
Atlantic
Pomacanthus semicirculatus
Korean Angelfish
1
Indo-Pacific
Pomacanthus imperator
Imperial Angelfish
1
Indo-Pacific
ACANTHURIDAE
Acanthurus coeruleus
Blue Tang
1
Atlantic
Acanthurus achilles
Achilles Tang
1
Indo-Pacific
BALISTIDAE
Balistes vetula
Queen Triggerfish
2
Atlantic
MONACANTHIDAE
Alutera schoepfi
Orange Filefish
1
Atlantic
OSTRACIIDAE
Ostracion tuberculata
Ocellated Boxfish
1
Indo-Pacific
Lactophrys quadricornis
Cowfish
1
Atlantic
Lactophrys triqueter
Smooth Trunkfish
1
Atlantic
DIODONTIDAE
Chilomycterus schoepfi
Spiny Boxfish
1
Atlantic
Diodon hystrix
Porcupinefish
2
Atlantic
SCORPAENIDAE
Pterois volitans
Lionfish
1
Indo-Pacific
TRIGLIDAE
Prionotus evolans
Sea Robin
1
Atlantic
BATRACHOIDAE
Opsanus tau
Toadfish
12
Atlantic
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evidently increasing in number with the growth
of the organism. It should be noted here that the
increase in total size of the individuals is not
entirely cytoplasmic but most of it is due to
swelling or distention from ingestion of food
material.
In addition to the meganucleus, a number of
micronuclei are usually present, invariably in
the interphase stage. Sikama (1938) reported
5-6 micronuclei, while Brown found 4-7 in to-
mites, with this number persisting in the young
trophont. In any event, micronuclei are also
clearly visible in some of our preparations of
trophonts of various dimensions (PI. figs. 7 & 17).
Tomont (PI. figs. 8-15). No sections were
made of the tomonts. The number of membranes
forming the cyst was not clearly evident. Most
of the tomonts showed at least 4 membranes;
Sikama (1961) suggests that the cyst wall is
formed by the 10 layers of very thin lamellae,
at least 6 forming the outer cyst wall. Occasion-
ally, the membranes are abnormally formed.
Tomites (PI. figs. 16 & 17). The pear-shaped
tomites clearly show the four spherical bodies
making up the nucleus, occupying at least two-
thirds of the posterior end of the body. The baso-
philic inclusions are not formed at this stage.
The number and arrangement of the kineties
was not established but the cilia as well as the
buccal membranes are well developed. The
young trophonts stained with hematoxylin show
the complex structure of the meganucleus and
the micronuclei (PI. fig. 17).
Pathogenesis
Fishes maintain an immunity by premunition,
i.e. by the presence of the parasite but without
evidence of pathogenic lesions. The factors re-
sponsible for the pathogenicity of Cryptocaryon
or Ichthyophthirius are still not known. En-
zootics in freshwater fishes caused by Ichthyoph-
thirius invariably starts with a sudden drop in
temperature. The inocuous trophont drops off
the host, settles to the bottom and becomes trans-
formed into the tomont, which eventually gives
rise to hundreds of astomatous, non-feeding,
free-swimming ciliates, which swarm towards the
same or different host. Once contact is made,
the ciliates develop a buccal apparatus and vigor-
ously burrow into the skin epithelium, causing
the papules characteristic of Ichthyophthiriasis.
As the trophonts grow at the expense of the host,
they become visible to the naked eye and give
rise to the typical white spot lesions well known
to aquarist and fish specialists.
The initiation of the cycle in Cryptocaryon,
however, is not dependent on the drop in temp-
erature, even though the end result is similar.
The lesions on the skin of marine fishes do not
necessarily appear as white spots but rather as
numerous minute, grayish vesicles. Like Ichthyo-
phthirius, the tomites swarm towards susceptible
host invading the epithelium of the gills and skin.
The irritating effects of the parasites, which
may be a mechanical process or caused by chem-
ical substances produced by the ciliates, is mani-
fested by the excessive production of mucous on
the body and gills. The petechial lesions on the
body and in the gills may be foci for secondary
infections with non-specific Pseudomonas. Heavy
infections invariably result in death of the host.
The lesions on the gills are more dramatic. The
parasites invade the epithelial lining of the lamel-
lae, causing considerable erosion of tissue and
excessive effusion (PI. fig. 1). In some instances,
the parasites also invade the eyes, frequently
causing blindness.
An effective treatment for Cryptocaryoniasis
was developed by Dr. Morris Baslow, formerly
of our staff, but the material should be used with
extreme caution because of its toxicity. Diseased
fish are treated with 1 cc. of the following stock
solution added to each 25 gallons (U.S.) of sea
water: Formalin, 100 cc.; cupric acetate, 8
grams; Tris, 92 grams. The solution will have a
final adjustment of pH at 7.5 at 24°C. Usually,
a single treatment is sufficient but can be re-
peated if needed.
A simpler, less toxic but still an effective rem-
edy, at least for treating skin and eye infections
in Pterois volitans, is to add 0.15-0.2 ppm of
copper sulfate— citric acid solution to the treat-
ment tank and enough methylene blue ( 1 cc. of
1 % solution per 2.5 gallons of water) to pro-
duce a clear blue color. The treatment should
be repeated at intervals of 5 days for at least 15
days.
Discussion
There is little doubt that the ciliate responsi-
ble for certain enzootics in marine fishes kept at
“tropical” temperatures (22-25°C) in the New
York Aquarium is the same as that reported by
Sikama (1937, 1938, 1960, 1961 ), Brown (1950,
1951), de Graaf (1962), and as that seen by
Laird (1965) in Singapore fishes in 1955. The
ecto-parasite was first reported as Ichthyoph-
thirius multifilis by Sikama in 1937 in a Japanese
paper which was translated into German in 1938.
In 1961, he redescribed and named the organism
Ichthyophthirius marinus, recognizing certain
morphological and cytological details that dis-
tinguished it from the freshwater species. The
1966]
Nigrelli & Ruggieri: Enzootics in the New York Aquarium
101
description by Brown (1951, 1963), by Sikama
( 1961 ) and in the present contribution definitely
establish Cryptocaryon irritans as a distinct
genus and species closely related to lchthyop-
thirius multifilis. The ciliate, according to Corliss
(1961), belongs to the Order Hy menostomatida,
Suborder Tetrahymenina and Family Ophyro-
glenidae (=lchthyophthiriidae) .
With the increased importation of Hawaiian
and Indo-Pacific fishes by various aquariums in
the world since the Second World War, Crypto-
caryon irritans has now become established as
an important disease-producing entity in marine
fishes kept in captivity at temperatures ranging
from 20 to 26°C. Once established, the parasites
show very little host specificity, as can be judged
from the host list in Table 1, which shows that
fishes affected in the New York Aquarium in-
clude both North and South Atlantic species.
The parallelism of Cryptocaryoniasis to Ich-
thyophthiriasis of freshwater fishes is striking, a
phenomenon also seen with other ciliates. For
example, many marine fishes may also become
infected with Trichodina or Trichodina- like spp.
(PI. fig. 18) and/or with Chilodonella- like spec-
ies (PI. figs. 19 & 20) ; the latter ciliate, although
known to occur in salt or brackish waters, either
free-living or as ecto-commensal on amphipods,
has not been previously reported as a parasite of
marines fishes.
Summary
1. Cryptocaryon irritans Brown, 1951 ( =
Ichthyophthirius marinus, Sikama, 1961) is re-
ported from the skin, gills and eyes of Indo-
Pacific and Atlantic fishes in the New York
Aquarium.
2. The life history, cytology, pathogenesis and
treatment are described.
References
Brown, Eleanor M.
1951. (A new parasitic protozoan the causal or-
ganism of a white spot disease in marine
fish . . . Cryptocaryon irritans gen. & sp.
n.). Agenda Sci. Meetings, Zool. Soc.
London, 1950, No. 11: 1-2.
1963. Studies on Cryptocaryon irritans Brown.
Progr. in Protozoology, pp 284- 287. (Pro-
ceedings of the 1st Intern. Congr. on Pro-
tozoology held in Prague, Aug. 22-31,
1961. Czechoslovak Acad. Sciences, Publ.).
Corliss, John D.
1961. The Ciliated Protozoa. Pergamon Press.
New York. 310 pp.
de Graff, F.
1962. A new parasite causing epidemic infection
in captive coral fishes. In: Iei Congres
International D'Aquariologie, Monaco,
1960. Bulletin de l’Institut Oceanograph-
ique. Numero special 1A, Vol. A: 93-96.
Kudo, Richard, R.
1966. Protozoology. Charles C. Thomas, Publ.
Springfield, 111. 1174 pp.
Laird, Marshall
1965. Personal communication.
Sikama, Yasumasa
1937. “Preliminary report on the white spot dis-
ease in Marine Fish.” “Suisan-Gakukai”,
vol. 7 (3): 149-160, 4 pis. (In Japanese).
1938. Uber die Weisspunktchenkranheit bei See-
fischen. The. J. Shanghai Sci. Inst., Sec.
Ill, 4: 113-128.
1960. (Contribution to the Biological Study of
the diseases and parasites of fish in Japan.
No. 2. White Spot Disease in Marine Fish
and Some Similar Diseases). “Sogo-
Kaiyokagaku” (Bull. Marine Sci.), vol. 2:
189-200. Japanese Institute for Marine
Science, Nihon University, (tn Japanese).
1961. On a New Species of Ichthyophthirius
Found in Marine Fishes. Sci. Rept. of the
Yokosuka City Mus. No. 6: 66-70.
1962. (Study on White Spot Disease in Marine
Fish). “The Agriculture”, vol. 10 (1): 29-
90, 13 pis., 97 figs.
102
Zoologica: New York Zoological Society
[51:9
Fig. 1
Fig. 2
Fig. 3
Fig.
Fig.
Fig.
Fig.
Fig.
EXPLANATION OF PLATES
Plate I
The gills of an Atlantic squirrelfish, Holo-
centrus ascensionis, infected with Crypto-
caryon irritans, a marine hymenostomatid
ciliate. Note the various sizes and shapes
of the parasite and excessive production
of mucous. In extreme infections, the gill
epithelium is completely denuded. 50 X-
Free-swimming trophont with character-
istic shape and extended buccal apparatus.
600 X-
Plate II
Another ciliate with buccal end slightly
retracted. 600 x.
[Figs. 2 & 3 show relatively large trophonts
(about 135 X 115 microns) filled with
food material which is responsible for the
distention. The food material consists of
cells, cellular debris and blood.]
Silver nitrate preparation of a larger tro-
phont; note the parallel arrangement of
the kineties, terminating in a ring around
the buccal apparatus. 300 X-
Plate III
Photograph of a fairly advanced stage of
development of Cryptocaryon irritans
showing the characteristic beaded arrange-
ment of the nucleus. Haematoxylin stained
preparation made by Dr. Marshall Laird in
1955 from Singapore fishes. About 1200 X-
Section of the gills of scup, Stenotomus
chrysops, from the North Atlantic; show-
ing ciliate cut at the level of the nucleus.
According to Dr. Eleanor Brown (1963),
the true chromatin is the coarse network;
small granules and the larger inclusions in
vacuoles, although basophilic are Feulgen-
negative. 1350 X-
Plate IV
Another section of the gills seen in fig. 6,
showing the parasitic ciliates within the gill
epithelium. The darkly staining spherical
bodies are probably micronuclei. 600 X-
Tomonts, or encysted stage, showing the
variability in size, shape and structure of
the cyst wall; all are viable cysts. 150 X-
Fig. 9. Details of early division are obscured be-
cause of the dense inclusions. The inita-
tion of division is indicated by the develop-
ment of cytoplasmic vacuoles, shown as
light areas in this photo 24 hours after
encystment. Oodinium, a parasitic dino-
flagellate that also reproduces in the en-
cysted stage is in the 4-cell stage. 150 X.
Plate V
Cellular division, which is unequal, begins
at one end, shown here as a polar cap.
Note the elongate shape of the tomont.
150 X-
The polar cap divided further to form a
group of cells. Note the spherical shape of
the tomont and difference in size. 150 X-
Later division occurs in the residual mass,
giving rise to a number of similar sized
cells within the cyst. 150 X-
Fully developed tomites show motility
within the cyst; they appear to emerge
from a small opening (or openings) on
one side of the cyst wall. 150 X-
Cyst ruptured by mechanical pressure to
show the numerous tomites. 50 X-
Plate VI
Cyst or tomont with a few tomites still
present, indicating that the cyst wall is
not ruptured or dissolved in order to re-
lease the free-swimming stage. 150 X-
One of numerous pear-shaped newly
emerged free-living tomite showing the
typical spherical bodies making up the
nucleus; the buccal structure is well de-
veloped. 600 X-
A very young trophont showing the four
.spherical bodies that make up the mega-
nucleus and three prominent micronuclei.
Delafield hematoxylin stained preparation
made by Dr. Marshall Laird in 1955, from
Singapore fishes. 600 X-
Trichodina-Uke sp. on gills of black sea
bass (Centropristes striatus) 300 X-
Plate VII
Chilodonella-Mke sp. on gills of rainbow
parrotfish (Scarus guacamaia). 300 X-
Details of Chilodonella- like sp. Note typi-
cal oral basket membranelle. Hematoxylin-
Eosin. 1350 X.
Fig. 10.
Fig. 11.
Fig. 12.
Fig. 13.
Fig. 14.
Fig. 15.
Fig. 16.
Fig. 17.
Fig. 18.
Fig. 19.
Fig. 20.
NIGRELLI & RUGGIERI
PLATE I
FIG. 1
FIG. 2
ENZOOTICS IN THE NEW YORK AQUARIUM CAUSED BY CRYPTOCARYON IRRITANS BROWN,
1951 ( = ICHTHYOPHTHI RIUS MARINUS SIKAMA, 1961), A HISTOPHAGOUS CILIATE IN
THE SKIN. EYES AND GILLS OF MARINE FISHES,
NIGRELL1 & RUGGIERI
PLATE II
FIG. 3
FIG. 4
ENZOOTICS IN THE NEW YORK AQUARIUM CAUSED BY CRYPTOCARYON IRRITANS BROWN,
1951 ( = ICHTHYOPHTHIRIUS MARINUS SI KAMA, 1961), A HISTOPHAGOUS CILIATE IN
THE SKIN. EYES AND GILLS OF MARINE FISHES.
NIGRELLI & RUGGIERI
PLATE III
FIG. 6
ENZOOTICS IN THE NEW YORK AQUARIUM CAUSED BY CRYPTOCARYON IRRITANS BROWN,
1951 ( = ICHTH YOPHTH I R1 US MARINUS SIKAMA, 1961), A HISTOPHAGOUS CILIATE IN
THE SKIN, EYES AND GILLS OF MARINE FISHES.
NIGRELLI & RUGGIERI
PLATE IV
FIG. 7
FIG. 8
FIG. 9
ENZOOTICS IN THE NEW YORK AQUARIUM CAUSED BY CRYPTOCARYON IRRITANS BROWN,
1951 ( = 1CHTH Y OPHTH I R! US MARINUS SIKAMA, 1961). A HISTOPHAGOUS CILIATE IN
THE SKIN. EYES AND GILLS OF MARINE FISHES.
NIGRELLI a RUGGIERI
PLATE V
FIG. 14
ENZOOTICS IN THE NEW YORK AQUARIUM CAUSED BY CRYPTOCARYON IRRITANS BROWN,
1951 ( = ICHTHYOPHTHI Rl US MARINUS SIKAMA, 1961). A HISTOPHAGOUS CILIATE IN
THE SKIN. EYES AND GILLS OF MARINE FISHES.
(MIGRELL1 & RUGGIERI
PLATE VI
FIG. 15
FIG.
FIG. 18
- «
17
ENZOOTICS IN THE NEW YORK AQUARIUM CAUSED BY CRYPTOCARYON IRRITANS BROWN,
1951 ( = ICHTHYOPHTHIRIUS MARINUS SIKAMA. 1961), A HISTOPHAGOUS CILIATE IN
THE SKIN, EYES AND GILLS OF MARINE FISHES.
NIGRELLI a RUGGIERI
PLATE VII
FIG. 19
FIG. 20
ENZOOTICS IN THE NEW YORK AQUARIUM CAUSED BY CRYPTOCARYON IRRITANS BROWN,
1951 ( = ICHTH YOPHTH I R I US MARINUS SIKAMA, 1961), A HISTOPHAGOUS CILIATE IN
THE SKIN, EYES AND GILLS OF MARINE FISHES.
10
Analysis of Underwater Odobenus Calls with Remarks on the
Development and Function of the Pharyngeal Pouches1,2
William E. Schevill*, William A. Watkins*,
& Carleton RAYf
* Woods Hole Oceanographic Institution,
Woods Hole, Mass.
&
t Osborn Laboratories of Marine Sciences,
New York Aquarium
New York Zoological Society
Brooklyn, N. Y.
(Plates I-V; Phonograph Disk)
WE HERE report underwater sounds
made by a 10-year-old Atlantic walrus
(NYA No. 1: “Olaf”), Odobenus r.
rosmarus (Linne) 1758, captive at the New York
Aquarium since a little over a year of age. We
distinguish three categories. Most often heard
is a short, rasping sound, next are series of clicks,
and rarest is a striking bell-like sound. These are
all true underwater sounds, made with the mouth
shut and the head submerged. Examples of each
are given on the accompanying phonograph disk.
The familiar in-air bellow, grunt, and mellow
whistle couple well with water when made by a
partially immersed animal, but are not discussed
here.
The rasps and clicks are evidently usual under-
water sounds of walrus. We have heard and re-
corded them on several occasions since 1963.
The bell-like sounds are made less frequently and
appear to be associated with the development of
the pharyngeal pouches.
’Contribution No. 1776 from the Woods Hole Ocean-
ographic Institution.
2This work was supported by Contract Nonr 4446
and Nonr 4029 between the Office of Naval Research
and the Woods Hole Oceanographic Institution. Record-
ing equipment was provided through Grant GA-126 from
the National Science Foundation to the New York
Zoological Society.
Material and Methods
The pool in which the walrus was confined is
21 x 12 m and 2.5 m in depth, and cement and
glass lined. The walrus shares the pool with three
grey seals , Halichoerus grypus (Fabricius) 1791,
which were not in the water when the recordings
here analyzed were made in March 1965 by Ray,
using an LC-50 (Atlantic Research) hydrophone,
a transistor pre-amplifier and a Nagra III B tape
recorder. Analysis playback was by means of a
Crown (B 800 series) recorder. The entire sys-
tem was essentially flat from 50 to 10,000 cps.
The spectographic analyses were made on a Kay
Electric Vibralyzer.
Results
•The rasps and clicks have some features in
common. The rasp begins with 4 to 10 pulses
emphasizing a frequency between 400 to 600
cps, about 0.01 second apart. As the call pro-
gresses, both intensity and repetition rate in-
crease, producing a nearly continuous sound
with harmonic structure and an apparent base
frequency of 200 to 300 cps. The whole event
is over in 0.1 to 0.2 second. Plate I gives an
example.
The clicks or pulses, Plate II, resemble the
rasps in acoustic structure, although they sound
very different to the listener. Each click is an
103
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[51:10
entity lasting 0.015 to 0.020 second, and with an
appreciable pause before the following click, 10-
per-second being the highest repetition rate that
we have noted. Like the rasp, the clicks have a
base frequency near 400 cps, but with a sharp
front. They exhibit other frequencies and may
have harmonics as high as 10,000 cps. The base
frequency is not always the most intense. The
listener notes a metallic resonance in some of
these clicks, usually the latter ones of a series,
in the band from 500 to 1500 cps.
The most striking of the walrus sounds is the
■'bell.'' Although well known to the Eskimo, it
is not conspicuous in the literature; we have
found only two references (Brooks, 1954, and
Fay, 1960). This sound is clearly audible in the
air and has been heard only when the animal is
partially or shallowly submerged or, rarely, out
of water. Here we discuss the sounds as heard
underwater. At the time, the walrus was floating
at the surface with his head hanging down. The
bell sound lasts 1 to 1.5 seconds, decaying gradu-
ally. As in an actual bell, the subsidiary frequen-
cies and harmonics die out, leaving the funda-
mental ringing. Our animal’s fundamentals
ranged from 400 to 1200 cps. The analyses show
that there are two “bells” involved, sometimes
differing in fundamental frequency by as much
as about 400 cps. This difference may vary from
call to call; in one instance, calls 1.5 seconds
apart emphasized first the lower frequency,
which happened to be 850 cps, and then the
higher, 1200 cps. In Plate III, the first of the two
calls shows such a double frequency (about 50
cps apart). We presume that this tone variation
is under the animal’s control, as particularly in-
dicated in the glissando of some of the second
group of “bells” in the phonograph record; this
implies changing pressure or volume in the air-
filled pouch. Each “bell” begins with a transient
pulse much like the click described above, which
seems to be the exciter or striking of the “bell.”
Discussion
Clues to the use to which Odobenu s puts these
sounds may be derived from the behavior and
anatomy of the captive recorded here. Its right
eye is shrunken and its left cornea is scarred, and
therefore we believe that its vision is impaired.
Yet the animal, often swimming with eyes closed,
experienced no orientation difficulties. It emitted
only the rasps and clicks while swimming; per-
haps this may have been echo-location, but since
the walrus was in very familiar uncluttered sur-
roundings, it may have been depending on mem-
ory for orientation.
The bell-like sound is closely associated with
sexual activity in this animal, for instance when
the walrus is floating head down and indulging
in masturbation, Plate IV, or during coition,
Plate V, sometimes with young female walrus
and sometimes with male or female Halichoerus
as partners. The pharyngeal pouches first became
evident at five years of age. Their use, especially
during sex play, increased as the pouches gained
in size. The bell-like tone was first noted at seven
years of age, when Olaf was copulating with a
young female walrus out of water. In that in-
stance, the sound was made in air, though with
mouth and nostrils closed.
Fay (1960, p. 369) notes that the St. Lawrence
Islanders and the people of Barrow relate these
"bells” to the paired inflatable pharyngeal
pouches which are variously and not always
symmetrically developed. As Fay points out,
they have generally been called oesophageal ex-
pansions, but Brooks and Fay specify that they
are pharyngeal diverticula. They are not devel-
oped in young animals and some females, and
attain maximum size in males, sometimes ex-
tending nearly to the posterior border of the
thoracic cavity, with a capacity as great as 25
and even over 50 liters (Fay 1960, p. 363). In
the captive described here it is about 30 liters,
as estimated from the measurements on the liv-
ing animal (pouch estimated 60 cm long, 45 cm
wide, 20 cm high). The pouches are capable of
being individually inflated, Plate IV.
We have, quite by accident, confirmed that
these pouches act as resonators for the “bell.”
During an Eskimo walrus hunt with Ray present
in May, 1963, an adult male walrus was shot while
resting on ice; it died almost immediately with
one pharyngeal pouch inflated. The skin and fat
were removed laterad to the pouch, exposing it.
When it was struck with the flat of a knife blade,
a bell-like tone almost identical to that recorded
was produced.
Both Sleptzov, 1940, (who says that the
pouches are symmetrical in embryos, but asym-
metrical in adults) and Fay, 1960, favor adjust-
ment of buoyancy during rest and sleep in water
as the pouches’ primary function. We suggest
that the pouches are a secondary sexual charac-
teristic, used for both sound production and flo-
tation during courtship and coition, as seen in
our captive. Flotation during rest would be use-
ful, as well.
The reported asymmetry of these pouches
offers a possible explanation of the two variable
tones that we have noted. The rapid changes
imply subtle muscular and pneumatic control.
One would expect tone differences between dif-
ferent individuals, and perhaps on different oc-
casions. We note that our subject is an Atlantic
walrus of the typical subspecies, which in this
1966]
Schevill, Watkins & Ray: Underwater Odobenus Calls
105
trait at least does not seem to differ from O. r.
divergens (Illiger) 1815 from Alaskan waters.
Sleptzov, 1940, describes a “swim-bladder” tra-
cheal dextral diverticulum in males of Histrio-
phoca fasciata, and alludes to less pronounced
developments in Emnetopicis jubata, Erignathus
barbatus , Phoca vitulina largha, and Phoca
(Pusa) hispida. Perhaps some special sounds may
be listened to from these species.
Summary
Three underwater calls of a captive Odobenus
are described and analyzed: rasps (lasting 0.1
to 0.2 second, with emphasis between 200 and
600 cps), clicks (lasting 0.015 to 0.020 second
at repetition rates up to 10 per second, with a
base frequency near 400 cps ) , and bell-like tones
( lasting 1 to 1 .5 seconds with fundamentals rang-
ing from 400 to 1200 cps) . The bell-like tone is
associated with the development of the pha-
ryngeal pouches and is used during courtship
and coitus.
References
Brooks, J. W.
1954. A contribution to the life history and ecol-
ogy of the Pacific walrus. Alaska Coop.
Wildl. Research Unit, Spec. Rept. 1, 103
PP-
Fay, Francis H.
1960. Structure and function of the pharyngeal
pouches of the walrus ( Odobenus rosmarus
L.) Mammalia, 24, 3. pp. 361-371, 2 text-
figs.
Sleptzov, M. M.
1940. O prisposobleniyakh k plavaniyu lastono-
gikh. On the adaptations to swimming in
the pinnipeds. Zoolog. Zhurnal, 19, 3, pp.
379-386, 7 text-figs., English summary.
106
Zoologica: New York Zoological Society
[51:10
EXPLANATION OF PLATES
Plate I
The rasp was the most common underwater sound
heard from the walrus. A 240 cps bandwidth filter
was used in analysis.
Plate II
The underwater clicks of the walrus often have a
metallic sound. The analyzing filter bandwidth was
240 cps.
Plate III
The bell-like sound of the walrus has a long, slowly
decaying resonance. The analyzing filter used here
had a 12 cps bandwidth.
Plate IV
“Olaf." 6 years old, with right pharyngeal pouch
inflated.
Plate V
“Olaf,” 7 years old, during coition with a 1-year-old
Pacific walrus. Bell sounds were made at the time.
Inserted
Phonograph disk of underwater calls of captive
(Olaf).
SCHEVILL, WATKINS 8c RAY
0 0.1 0.2 0.3 0.4
TIME - SECONDS
PLATE I
0.5
ANALYSIS OF UNDERWATER (ODOBENUS) CALLS WITH REMARKS ON THE
DEVELOPMENT AND FUNCTION OF THE PHARYNGEAL POUCHES
ANALYSIS OF UNDERWATER (ODOBENUS) CALLS WITH REMARKS ON THE
DEVELOPMENT AND FUNCTION OF THE PHARYNGEAL POUCHES
SCHEVILL, WATKINS & RAY
PLATE II
ro
CM
*1
S P
cn
I
O)
L.
/'C/75
ANALYSIS OF UNDERWATER (ODOBENUS) CALLS WITH REMARKS ON THE
DEVELOPMENT AND FUNCTION OF THE PHARYNGEAL POUCHES
SCHEVILL, WATKINS & RAY
PLATE III
O
bi b
cjn
£
ro
O
po
Ol
SCHEVILL. WATKINS & RAY
PLATE IV
ANALYSIS OF UNDERWATER (ODOBENUS) CALLS WITH REMARKS ON THE
DEVELOPMENT AND FUNCTION OF THE PHARYNGEAL POUCHES
ANALYSIS OF UNDERWATER (ODOBENUS) CALLS WITH REMARKS ON THE
DEVELOPMENT AND FUNCTION OF THE PHARYNGEAL POUCHES
SCHEVILL. WATKINS & RAY
PLATE V
' • - m . , . ... ,
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ZOOLOGICA
SCIENTIFIC CONTRIBUTIONS OF THE
NEW YORK ZOOLOGICAL SOCIETY
VOLUME 51 • ISSUE 4 • WINTER, 1 966
PUBLISHED BY THE SOCIETY
The ZOOLOGICAL PARK, New York
Contents
PAGE
11. Gene and Chromosome Homology in Fishes of the Genus Xiphophorus.
By Klaus D. Kallman & James W. Atz. Plates I- VI; Text-figure 1 107
12. On the Marking Behavior of the Kinkajou ( Potos fiavus Schreber). By
Ivo Poglayen-Neuwall. Plates. I-III 137
Index to Volume 51 153
Zoologica is published quarterly by the New York Zoological Society at the New York
Zoological Park, Bronx Park, Bronx, N. Y. 10460, and manuscripts, subscriptions, orders for back
issues and changes of address should be sent to that address. Subscription rates: $6.00 per year;
single numbers, $1.50, unless otherwise stated in the Society’s catalog of publications. Second-class
postage paid at Bronx, N. Y.
Published February 20, 1967
11
Gene and Chromosome Homology in Fishes of the Genus
Xiphophorus 1
Klaus D. K all man
Genetics Laboratory, Osborn Laboratories of Marine Sciences,
New York Aquarium, Brooklyn, N. Y. 11224
James W. Atz
The American Museum of Natural History
(Plates 1-6; Text -figure 1)
Contents
I. Introduction
page
I. Introduction 107
II. Materials and Methods 108
III. Results 110
1. The Macromelanophore Patterns .... 110
a. Xiphophorus maculatus 110
b. Xiphophorus variatus Ill
c. Xiphophorus milleri 113
d. Xiphophorus montezumae 113
e. Xiphophorus hellerii 117
2. The Micromelanophore Tail Patterns. . 119
a. Xiphophorus maculatus 119
b. Xiphophorus variatus 121
c. Xiphophorus milleri 122
d. Xiphophorus montezumae and
X. pygmaeus nigrensis 123
e. Xiphophorus hellerii 123
3. Chromosome Homology 123
a. Chromosomes with
Macromelanophore Patterns 123
b. Tail Spot Patterns 124
IV. Discussion 126
V. Summary 130
VI. Bibliography 131
1 These investigations were aided by a series of grants
from the U.S. Public Health Service, the latest of which
is Ca-06665, and by the facilities of the Department of
Ornithology of The American Museum of Natural His-
tory, New York, N. Y. 10024. The fish from the Rio
Chajmaic were collected on the 1963 American Museum
of Natural History Guatemalan Expedition which was
made possible by funds donated to the Department of
Ichthyology by Mr. James C. Greenway, Jr.
THE SIMILARITY of closely related spe-
cies is primarily the result of their descent
from a common ancestor, and there can
be little doubt that most of the gene loci in such
species are the same, although they are often
occupied by different alleles. Identical alleles may
be defined as alleles that have been inherited
from the ancestral form by two or more descend-
ed species or populations. Homologous alleles
are genes that occupy the same locus in different
species; often they are alleles' that have arisen
by mutation in one species but not in another.
In contrast, analogous genes are those that have,
or seem to have, the same function or effect,
but that cannot be traced to a common locus.
A fine distinction between identical and homo-
logous alleles is not always possible. An allele
may be the same in two species because the same
mutation occurred in both of them, rather than
because it was inherited from a common pro-
genitor—in which case the two genes would be
homologous, even though identical in structure.
Moreover, alleles that have different nucleotide
sequences can give rise to the same phenotypic
effect. Such alleles should be considered homo-
logous, but unless a molecular analysis is made,
which is at present possible in very few cases,
they will be considered identical.
Under the usual circumstances, genes can be
studied only indirectly by their phenotypic ef-
fects, and most characters are not governed by
107
108
Zoologica: New York Zoological Society
[51:11
a single major or principal gene, but by the
interaction of many, individually unidentifiable
genetic factors. Even within a single species,
the same structure or function may be the result
of different combinations of genes in different
individuals, because of gene substitutions and
repressor mutations— a phenomenon called the
“constancy of the phenotype” by Mayr (1963,
p. 280). In different populations of the same
species, as well as in closely related species,
identical characters may be based upon different
polygenic mechanisms; in these cases, even
though the characters themselves may be homo-
logous, their genetic basis cannot be considered
so (de Beer, 1958, p. 148). Therefore, in our
present state of knowledge, the only characters
suitable for the study of gene homology are those
under the control of a single major gene that
exists in at least two recognizably different al-
lelic states. Strikingly similar mutations that
have arisen in closely related species and similar
multiple allelic series that occur in congeneric
species have provided some of the most favorable
material for the study of gene homologies.
This paper is concerned with gene and chrom-
osome homologies in the well-known genus of
teleost fishes, Xiphophorus. Within this genus
several taxonomic levels are represented: (1)
geographically isolated populations belonging to
a single species, (2) morphologically recogniz-
able subspecies, (3) species, (4) superspecies,
and (5) less closely related species groups
(Rosen, 1960). Because the members of all of
these are interfertile to an appreciable degree,
critical genetic experiments that require hybridi-
zation can be performed. Roughly correspond-
ing to their taxonomic relationships, these fishes
exhibit strikingly similar or different patterns of
pigmentation, some of which are polymorphic
and are controlled by major genes. Most notable
are the tail-spot patterns, composed of small
melanophores (micromelanophores) in aggrega-
tions near the base of the caudal fin, and the
macromelanophore patterns, formed by large
pigment cells (often 0.3 to 0.5 millimeters in di-
ameter) that may occur on almost any part of
the body. The macromelanophore genes are
physiologically similar in that, with a single ex-
ception, they are capable of giving rise to pig-
ment cell abnormalities in hybrids. Four species
of Xiphophorus have populations that are poly-
morphic for both macromelanophore and tail-
spot patterns, one species for only tail-spot
patterns, another for only macromelanophore
ones, and two species exhibit neither type of
pattern. In Xiphophorus maculatus, which is the
most polymorphic species, at least 16 different
alleles have been recognized, half at the macro-
melanophore and half at the tail-spot locus.
Moreover, the less well-known species, X. vari-
atus, may prove to be just as phenotypically
diverse. The other four polymorphic species ex-
hibit relatively few pigment patterns, but the
genus as a whole provides a remarkable gamut
of opportunities to study gene homology.
II. Materials and Methods
In the first part of this paper, the macro-
melanophore patterns of Xiphophorus and the
genes responsible for them are briefly reviewed
and the morphology and inheritance of several
new patterns are described. In the second part,
the micromelanophore patterns are treated in
the same way. Crosses with a critical bearing on
the question of gene homology are analyzed in
the third.
At the present time, several laboratories are
studying the pigment patterns of Xiphophorus,
and a uniform system of nomenclature to de-
scribe the different patterns and alleles is needed.
One difficulty is that many of the patterns are
not well known and that sufficient comparative
material is often not available. Another source
of error has been that many of the stocks of
Xiphophorus have been obtained from commer-
cial sources. The geographical origins of these
fish are unknown. Moreover, many of the do-
mesticated stocks represent not pure species, but
fish descended from interspecific hybrids. For
example, there is little doubt that the striking red
and black pigment patterns of swordtails regu-
larly available in the pet trade are the result of
genes belonging to other species of Xiphophorus
that have been introduced into X. hellerii through
introgressive hybridization. Other commercial
stocks have hybrids between X. maculatus and
X. variatus as their basis. Some of these resemble
variatus, but have maculatus pigment genes and
vice versa.
The geographic origin of the fish in this report
and the expedition responsible for their collec-
tion are listed below:
Xiphophorus couchianus couchianus (Girard,
1859).
Pedigree h-28: Rio Santa Catarina, Nuevo
Leon ( 1939) Myron Gordon, Atz, Evelyn Gor-
don. Hybrids with X. v. xiphidium.
Strain Xc-G: Rio Santa Catarina, Nuevo Leon
(1958) Myron Gordon, Evelyn Gordon.
Xiphophorus variatus xiphidium (Gordon,
1932).
Pedigrees Px-20 to 23: Rio Purification,
Tamaulipas (1939) Myron Gordon, Atz, Evelyn
Gordon.
Pedigrees h-2, h-28: Rio Purification, Tamau-
1967]
Kallman & Atz: Gene and Chromosome Homology in Xiphophorus
109
f couchianus,
Rio Tamesi
/Rio Panuco | _______
•Rio Tecolutla "
Rio Nautla |
Rio Jamapa
/ , Rio Papaloapan
/ / ,Rio Coacacoalcos^N
/ . Rio/Tonala J
/ / / /Rio Grijalva (
1 ■/-/— ciRio Usumacinta
xipbidium
pygmuem-
montezumae ■
[variatus
clemenciaeV
maculatus
'hellerii —
Text-fig. 1. The distribution of Xiphophorus (based
principally on Rosen, 1960). X. v. variatus, X. mon-
tezumae (with two subspecies), X. maculatus, and
X. hellerii (three of the four subspecies) have the
widest distribution. Not indicated on the map are
lipas (1939) Myron Gordon, Atz, Evelyn Gor-
don. Hybrids with X. v. variatus and X. c. couch-
ianus.
Pedigree 1184: Rio Santa Engracia, Tamau-
lipas (1958) Myron Gordon, Evelyn Gordon.
Pedigree 1228, 1238: Rio Santa Engracia,
Tamaulipas (1962) Kallman.
Xiphophorus variatus variatus (Meek, 1904)
Pedigrees h-2, h-61: Rio Axtla, San Luis
Potosi (1939) Myron Gordon, Atz, Evelyn
Gordon. Hybrids with X. v. xiphidium and X.
maculatus.
Pedigree 1752: Rio Tamesi, Tamaulipas
(1957) Rosen, Malcolm Gordon, Myron Gor-
don.
Pedigree 912: Rio Tamesi, Tamaulipas (1957)
the ranges of X. v. evelynae, which is restricted to
headwater streams of the Rio Tecolutla, and X.
hellerii alvarezi, which is known only from the Rio
Santa Domingo, a tributary of the Rio Usumacinta
in the state of Chiapas, Mexico.
Rosen, Malcolm Gordon, Myron Gordon. Hy-
brids with X. v. evelynae.
Xiphophorus variatus evelynae Rosen, 1960.
Pedigree 912: Rio Necaxa, Puebla (1957)
Rosen, Malcolm Gordon, Myron Gordon. Hy-
brids with X. v. variatus.
Xiphophorus montezumae montezumae Jor-
dan & Snyder, 1900.
Pedigree 733: Rio Salto, San Luis Potosi
(1957) Rosen, Malcolm Gordon, Myron Gor-
don.
Pedigree 1817: Rio Salto, San Luis Potosi
(1965) Klaus Kallman, Judith Kallman.
Xiphorphorus montezumae cortezi Rosen,
1960.
Pedigrees Xmc-21 to 29 and descendants.
110
Zoologica: New York Zoological Society
[51:11
Strain 38: Rio Axtla, San Luis Potosi (1939)
Myron Gordon, Atz, Evelyn Gordon.
Xiphophorus milleri Rosen, 1960.
Pedigree 1374: Lake Catemaco, Veracruz
(1963) Kallman, Rosen.
Pedigree 1543: Lake Catemaco, Veracruz.
Obtained in 1963 through the courtesy of Dr.
Robert R. Miller, University of Michigan.
Xiphophorus maculatus (Guenther, 1866).
Strains Jp 30, Jp 163 A and B: Rio Jamapa,
Veracruz. Pure-line, inbred.2
Strain Gp: Rio Grijalva, Tabasco. Pure-line,
inbred.2
C-30: a sub-line of Jp 30.
Strains Hp-1, Hp-2: Rio Hondo, British Hon-
duras. Pure-line, inbred.2
Fish Cp-1 1 : Rio Coatzacoalcos (1948) Myron
Gordon, Atz, F. G. Wood, Jr. A single male.
Strain Np: New River, British Honduras
( 1954) Myron Gordon, Fairweather, Chaveria.2
Pedigree 1342: Rio San Pedro de Martir
(1963) Kallman, Rosen.2
Pedigree 1900: Belize River, British Honduras
(1966) Klaus Kallman, Judith Kallman.
Xiphophorus hellerii hellerii.
Strain Cd: Cordoba, Rio Jamapa, Veracruz.
Obtained in 1949 through the courtesy of Dr.
Reeve M. Bailey, University of Michigan. Ori-
ginally collected by Dr. Clarence L. Turner.
Xiphophorus hellerii strigatus Regan, 1907.
Strain 3B: Arroyo Zacatispan, Rio Papaloa-
pan, Oaxaca (1939) Myron Gordon, Atz, Eve-
lyn Gordon.
Strain Cx: Near Almagres, Rio Coatzacoalcos,
Oaxaca (1948) Myron Gordon, Atz, F. G.
Wood, Jr.
Pedigree 1377: Rio Sarabia, Oaxaca (1963)
Kallman, Rosen.
Xiphophorus hellerii guentheri Jordan & Ever-
mann, 1896.
Strain Bx: Belize River, British Honduras
(1949) Myron Gordon, Fairweather.
Strain Hx: Rio Lancetilla, Honduras (1951)
Myron Gordon.
Strain Gx: Rio Grijalva, Tabasco (1952)
Myron Gordon.
These fishes were bred and maintained at the
Genetics Laboratory according to the method
of Gordon ( 1950a) and Kallman (1965a). Most
of them were eventually preserved either in
2 The origin of these strains has been explained in
detail by Kallman (1965a).
formalin or alcohol to make them available for
future reference.
III. Results
1. The Macromelanophore Patterns.
a. Xiphophorus maculatus.
The macromelanophore patterns of this spe-
cies have been studied in greater detail than
those of any other member of the genus. Five
macromelanophore patterns have been described
by Gordon (1948, 1951c) and Gordon & Gor-
don (1957) from natural populations: spotted
(Sp) with irregular spotting along the flanks;
striped (Sr) with discrete rows of macromelano-
phores, some of which are combined to form
spots, along the flanks; spotted dorsal (Sd) with
irregular spotting in the dorsal fin; nigra (N)
with irregular blotches or bands on the flanks;
and spotted belly (Sb) with heavy spotting on
the ventral half of the body, especially in the
area above the base of the anal fin. All fish with
spotted belly are descended from a single male
collected in 1932 from the Rio Papaloapan, the
only one of its kind ever seen in nature (Gordon,
1946a) . Two patterns that are known only from
domesticated stocks of unknown geographic ori-
gin have been studied in some detail: fuliginosus
(Fu) in which the fish are covered more or less
uniformly by macromelanophores and have a
sooty appearance (Kosswig, 1938; Gordon &
Baker, 1955; MacIntyre, 1961a; Oktay, 1954),
and a type of spotted pattern (Sp') that produces
g pepper-and-salt effect (Gordon, 1951b). The
phenotypic expression of the macromelanophore
genes is greatly influenced by genetic modifiers
( Gordon, 1951a; Gordon & Gordon, 1 957 ). The
phenotypic variation shown by the nigra pattern,
however, may not result solely from modifying
genes, since Bellamy & Queal ( 1951 ) recognized
two additional alleles, thin nigra (Nl) and ex-
tended nigra (Ne). Unfortunately, they never de-
scribed their complete experiments nor provided
photographs of the patterns.
There is abundant evidence that the macro-
melanophore patterns in X. maculatus are con-
trolled by dominant, sex-linked alleles (Bellamy,
1922; Bellamy & Queal, 1951; Gordon, 1927,
1937a, 1947a, 1951c, 1952; Kallman, 1965a;
Oktay, 1959a, b, 1962). Two cases of crossing
over within the macromelanophore locus have
been recorded (Gordon, 1937a; MacIntyre,
1961c) , and this suggests that the macromelano-
phore genes form a super-gene or a pseudoallelic
or suballelic series.3
3 The proper term for this situation presents a prob-
lem. Atz (1962) called these macromelanophore genes
pseudoalleles, but this term has been reserved for an
1967]
Kallman & Atz: Gene and Chromosome Homology in Xiphophorus
111
In X. maculatus, the macromelanophore gene
is closely linked to a locus controlling the ap-
pearance of yellow, orange, and red pigment
patterns. Crossing over between this and the
macromelanophore locus occurs in rare cases
(Fraser & Gordon, 1929; Gordon, 1937a, 1950b).
Breider (1936, 1938) and Kosswig (1948) of-
fered the opinion that Sp, N, Sb, Fu, Dr, R, Mo,
Rb, and RSp are all alleles, the last five of which
concern patterns with red or reddish pigmenta-
tion. For most of these, however, no critical
crosses demonstrating homology are available.
b. Xiphophorus variatus.
The pigmentary polymorphism of X. variatus
appears to be as great as that of X. maculatus,
but it has not yet been studied in detail. In the
subspecies, X. v. xiphidium, there is a macrome-
lanophore pattern, flecked (FI1), that produces
sharply defined, large, jet-black spots along the
flanks of the fish (Gordon & Smith, 1938, fig.
7B) .4 This spotted pattern is apparently identical
with the one studied by Zander (1962) and
Anders & Klinke (1965), as judged by their
descriptions and photograph. A second macro-
melanophore pattern is represented abundantly
in populations inhabiting the Rio Santa Engracia
(see Fig. 12). Its overall appearance is some-
what intermediate between Sr and Sp’ of X.
maculatus. In adult fish, the macromelanophores
typically are not arranged in spots, but instead
follow rather closely the reticulum (Rosen,
1960, p. 180; Atz, 1962, p. 156) that is formed
by bands of micromelanophores along the edges
of the scale pockets. Especially in the area be-
low the dorsal fin and on the caudal peduncle,
the macromelanophores may completely replace
the reticular micromelanophores. In many cases
macromelanophores have also “spilled over”
into the hexagonal or rhombic areas that are
usually free of melanophores. Nevertheless,
three distinct rows of macromelanophores can
obviously different relationship among genes, and the
macromelanophore genes might better be designated
suballeles according to the criteria of Serra (1965).
Since nothing is known about the fine structure of the
chromosomes of Xiphophorus, however, the exact type
of multiple allelism that is present must remain a ques-
tion. On the other hand, whether or not the macro-
melanophore alleles represent a super-gene, as defined
by Ford (1964, pg. 93), is also at present unknown.
Nevertheless, because it seems most likely that these
genes “act as a switch in the control of polymorphism,”
we shall consider them as parts of a super-gene that,
on rare occasions, may be separated by crossing over.
4 Called Sp by Gordon & Smith (1938), Gordon
(1943), Kosswig (1959), Zander (1962), and Anders
& Klinke (1965); also by Atz (1962), but see the fol-
lowing footnote.
almost always be distinguished: along the mid-
lateral line and the two horizontal scale rows
immediately above it. Anterior to the dorsal fin,
this pattern is represented by numerous isolated
macromelanophores or small elongated spots on
the reticulum. Fish in which this pattern is
strongly developed appear dusky, but never
black, and the name assigned to it is based on
this appearance, namely dusky, but we desig-
nate it as FI2 in accordance with our system of
not trying to give a separate and appropriate
name to every different but related pattern.5 &
In heterozygous fish, FI2 masks the heavy spot-
ting of FI1. When an FI1 FI2 female (phenotyp-
ically dusky) was mated to wild type male, the
two pigment patterns segregated among the off-
spring of both sexes (Table I, ped. 1320). When
a spotted female was mated to a dusky male,
the dusky pattern (FI2) was inherited only by
the female offspring while the males were of
two types, FI 1 and wild type (Table I, ped. 1324).
The two spotted patterns must be caused by
different sex-linked alleles and are not the result
of the action of modifiers on a single macro-
melanophore gene. In our stocks, both genes
are located on X chromosomes; in the stock of
Kosswig (1959), Zander (1962), and Anders
& Klinke ( 1 965 ) , the FI 1 gene is on the Y chrom-
osome.
We cannot trace Fu, a third macromelano-
phore pattern of xiphidium that was mentioned
by Kosswig (1948, p. 142), but if this investi-
gator is referring to the work of Myron Gordon
that was first reported in Gordon & Smith
(1938), it must be the gene we call FI1.
In another subspecies, X. v. variatus, several
macromelanophore patterns occur in nature
(Rosen, 1960, pp. 80-81), but only a few have
been studied in the laboratory. The pattern
punctatus, P, which was described by Kosswig
(1935 a, b) and which we designate as P1, con-
sists typically of numerous black spots that are
primarily located above the midlateral line and
are most numerous below and in front of the
dorsal fin, as judged by the photographs in
Kosswig (1935 a, b) and Rust (1939) and an
outline drawing by Zander (1962) and by direct
comparison with wild-caught fish described in
Atz (1962, p. 162). A similar pattern is present
in one of the stocks of the Genetics Laboratory
and is probably caused by the same allele, P1.
The original fish with this pattern were collected
in the Rio Boquilla of the Rio Tamesi drainage.
5In Atz (1962), crosses 903, 913, and 914, and fig.
10 concern dusky (FI2); the remaining crosses that in-
volve a spotted X.v. xiphidium, including 941, concern
FI1, as far as known.
112
Zoologica : New York Zoological Society
[51:11
Table 1. Inheritance of Two Macromelanophore Patterns, FI 1 and FI2,
in Xiphophorus variatus xiphidium
Pedigree Parents Offspring
Female
Male
Females
Males
FI 2
FI1
+
FI2 FI1
+
1251
1184-1/2 FI2
1228-12 FI1
30
22
1281
1238-1 +
1228-11 FI1
26
22
1320
1251-i/z FI2 (FI1)
1281-11 +
20
19
6 10
1324
1281-1/2 FI1
1251-11 FI2
25
17
15
1379
1281-% FI1
1281-12 +
5
9
10
3
1499
1379-1/2 FI1
1379-11 FI1
21
13
5
1647
1499-1/2 FI1
1499-11 +
10
3
11
3
1658
1499-4 FI1
1499-12 FI1
11
15
1711
1647-1 FI1
1647-11. +
5
3
5
5
1810
1711-1/2 +
1711-11 FI1
12
17
The punctatus pattern is strikingly different from
another spotted pattern, P2, that causes large,
intensely black spots most numerous along the
midlateral line. These spots may coalesce to form
an irregular black band in older fish see (Fig.
I).6 These two punctatus patterns are usually
impossible to tell apart in younger individuals,
and not until a brood of fish reaches an age of,
say, nine months can all its members be clas-
sified. There is, however, very little or no pheno-
typic overlap between the two patterns, once
they have fully developed. This holds true des-
pite the fact that old Px fish may become almost
entirely covered with spots, for even in such
cases the primary spotting— above the midlateral
line, in front of and under the dorsal fin— remains
apparent.
Another macromelanophore pattern of X. v.
variatus has been designated Sr by Kosswig
(1961), Zander (1962), and Anders & Klinke
(1965) because it somewhat resembles the
striped pattern (Sr) of X. maculatus. As judged
by the photographs and drawings of Gordon &
Smith (1938, figs. 9B, D) and Zander (1962),
this pattern is best developed along the mid-
lateral line below the dorsal fin and on the caudal
peduncle. In contrast, the striped pattern of X.
maculatus (populations from the Rio Jamapa
and from British Honduras) is most evident un-
6 The Sp of X. v. variatus discussed in Gordon (1943)
and Atz (1959) must include both P 1 and P -, since
these authors did not recognize that there is more than
one spotted pigment pattern. Evidently, Rosen (1960,
pg. 81) also did not, for he lumps all spotted patterns
of this species not occurring in the Rio Cazones (from
which living fish have never been brought to the labora-
tory) as “blotched.” Nevertheless, all the spotted pat-
terns of X. v. variatus treated by Atz (1962), and called
Sp by him, actually refer to P1, with the possible excep-
tion of the photomicrograph, fig. 18.
der and in front of the dorsal fin, and is virtually
absent or only weakly expressed on the caudal
peduncle. Because the two patterns are pheno-
typically distinct, we propose to call the one from
X. v. variatus lined (Li). In Gordon & Smith
(1938), there is a wild-caught male with a macro-
melanophore pattern that combines the features
of the lined (Li) and punctatus (P1) patterns.
When crossed with a spotted X. maculatus, at
least some of its male F1 offspring showed the Li
pattern alone. (All the F 1 females inherited Sp
from maculatus and were melanotic.) Evidently
P 1 and Li had segregated. Zander (1962) de-
scribed six interspecific crosses in which Li and
P1 also segregated, and it is most probable that
these are alleles.
A fourth pattern that involves spotting on
the sides may very well exist, but little is known
about it. Rust (1939, 1941) described some X.
variatus that were orange along their ventral
sides and in addition possessed some small spots
scattered over the caudal peduncle. As judged
by his photograph, this pattern is definitely dif-
ferent from P1 and P2. Rust attributed the black
speckling to the gene O for orange (which we
designate as Or in order to differentiate it from
the O for one-spot), but it is almost certain that
these spots resulted from a macromelanophore
allele closely linked to Or, as Breider (1949) has
suggested. That P1 and Or are distinct is also
shown in crosses between X. variatus and X. hel-
lerii. When introduced into a hellerii genome,
the punctatus pattern remains largely unchanged
or only slightly modified (Rust, 1941; Zander,
1962; Anders & Klinke, 1965), while the
macromelanophore allele associated with the
gene Or is greatly increased in expressivity (Kos-
swig, 1948; figures 5 and 6 in Rust, 1941). It is
interesting to note that in X. variatus, as in X.
1967]
Kallman & Atz: Gene and Chromosome Homology in Xiphophorus
113
maculatus, a locus that controls the appearance
of distinct xanthophore and erythrophore pig-
ment patterns is apparently closely linked to the
macromelanophore locus.
c. Xiphophorus milleri.
According to Rosen (1960), two macrome-
lanophore patterns can be distinguished pheno-
typically in X. milleri, one pattern consisting of c
more or less definite rows of spots arranged along ~
the dusky bands on the side, the other of irregu- ?
lar spots on the body. The latter pattern was pre- g
sent in some of the fish collected alive from Lake .2
Catemaco in 1963, and these have been bred in §“
the Genetics Laboratory (see Figs. 4 & 5). In +.
our strain, the spotting occurs only in the males ^
and consists of a fine speckling of macromelano- £
phores mostly along the ventral half of the z
caudal peduncle. The melanophores are most w
numerous around the base of the anal fin. In 5
some fish this area becomes solid black, and in a ^
few fish a state of melanosis has been detected. 05
Q
Since this spotted ventral pattern, Sv, shows z
strictly paternal inheritance (Table II), this c.
species presumably possesses an XX-XY type of
sex determination with Sv on the Y chromosome %
(Kallman, 1965b). h
d. Xiphophorus montezumae. £
The macromelanophore patterns of X. mon- ej
tezumae cortezi have been described by Atz H
( 1 962) . The spotted caudal pattern (Sc) consists °
typically of one or more irregular, elongated
patches of heavy pigmentation commencing £
close to the base of the middle or lower caudal «
fin rays and extending posteriorly for roughly o
one third of the fin’s length.7 The spotted pattern g
(At) consists of numerous deeply pigmented, z
roundish spots, mostly confined to the mid- and ^
post-dorsal regions above the midlateral line; |
as a fish grows older, spotting may also develop Q
in its caudal and dorsal fins (Atz, 1959, 1962). 8 g
Crosses involving wild-caught X. m. cortezi u,
and their descendants have been summarized in w
Table III. The At gene of cortezi is not sex-linked g
and behaves as an autosomal dominant. From £
the 15 crosses in which a single parent possessed gj
the At pattern, spotted and wild type offspring §
were obtained in equal frequency (89 At fe- l"H.
males, 88 At males, 94 + females, 77 + males). ®
w
■a
S3
<
7 Called Nc by Breider (1949) and Breider & Mom- ^
bour (1949).
8 At for atromaculatus, which, in Greek, means black
spotted or dressed in black spots (Brown, 1954). This
genetic factor was called Sp by Gordon (1943), Atz
(1962), Zander (1962, 1965), and Anders & Klinke
(1965).
ftJ
O
03
00
+ 05
+
05
a,
+ o?
+ £
+ +
£ 05
A 05
05 £
> 05 on Tf Os
CO *-H T-.
£ £ £ ^ ™
+ 05
IOOOOM
r- v© m vo on
VO
ON V3
II NO -h ro Nf t N VO — <
"T -T — I fs|
<< +
£
cq cq £ cq + 03 cq _lcq
“i on to _rT“"r
1 C4
i rl
r-r^r^^ooN’^-^t<NOOoooo
+ + £ + + £ £ “3 +£ £ ^ £
03 >
,rn''T ds
't’T'tOO'l-iOT’N'HX’tcc
r^r^*r-^H^HON,^tONOOrJoo,,=J-
S'
03 JD
O’HHUN,tO(SO'HT00ff)rri
,t^-TtiTfio)0'0'sor^tN>r^oooo
1 Either Ss or SsB.
114
Zoologica: New York Zoological Society
[51:11
Table III. Inheritance of Macromelanophore Patterns, At and Sc, in
Xiphophorus montezumae cortezi
Pedigre
Parents
Offspring
Pedigree
Phenotype
AtSc
Sc
At
+
Total
Xmc-
$
8
$
8
9
8
9
8
9
8
9
8
9
8
21
1
11
+
Sc
11
13
19
13
30
26
22
2
12
+
AtSc
3
1
6
6
6
4
12
14
23
3
13
At
+
4
1
9
6
5
10
14
21
24
4
14
At
+
5
4
9
8
14
12
25
5
15
At
At
9
6
1
6
10
12
26
6
16
At
At
10
2
2
2
12
4
27
7
17
At
Sc
2
2
3
2
1
5
5
28
8
18
+
At
4
2
2
3
6
5
29
9
19
At
At
18
35
6
11
24
46
30
21-1
23-11
+
AtSc
1
1
2
4
8
10
6
302
30-1
30-12
+
Sc
5
9
6
5
11
14
31
21-2
15-11
Sc
+
7
11
18
6
25
17
32
30-8
302-12
At
Sc
4
6
4
1
1
4
3
2
12
13
33
31-8
302-11
+
At
2
1
6
7
6
5
13
14
34
33-6
32-16
+
AtSc
1
1
2
5
7
4
9
11
35
33-7
32-17
+
AtSc
1
2
3
6
8
1
11
10
36
33-8
32-15
+
AtSc
2
1
2
6
9
5
4
13
16
37
32-2
33-11
AtSc
+
3
2
1
3
7
2
5
4
16
11
38
33-5
33-15
+
At
4
7
5
8
9
15
39
302-1
30-11
Sc
AtSc
1
1
2
3
6
1
40
33-1
33-11
At
+
1
19
3
14
7
33
11
41
32-14
32-14
AtSc
AtSc
5
7
1
3
4
1
3
1
13
12
Total
308
296
Four crosses in which both parents exhibited
the At pattern yielded spotted and wild type off-
spring in a ratio of 3:1 (97 At, 36 + ). This
indicates that the At parents were heterozygous.
The inheritance of the spotted caudal (Sc)
gene is difficult to study, however, because of
its low penetrance. Neither of the progenitors
of strain 38 exhibited the Sc gene, although it
must have it present in at least one of them
(Table IV). This strain has been inbred and
maintained in the Genetics Laboratory for more
than 15 generations. In the sixth generation, the
fish evidently became homozygous for At, be-
cause from then on no more fish appeared that
lacked this pattern. As reported by Atz (1962)
and Zander (1965), but without any supporting
data, the At and Sc genes are not allelic. During
10 generations of mating At Sc females with
AtSc males, not a single fish was obtained that
exhibited only the spotted caudal pattern. Dur-
ing the last 10 generations, 205 fish were At Sc
and 74 were At. The latter are undoubtedly the
result of nonpenetrance of the Sc gene. The
spotted caudal pattern is sometimes represented
by only a few macromelanophores, and a mating
of two spotted fish from the 11th and 12th
generations, respectively, resulted in five At and
nine At Sc offspring. Crosses between wild type
X. m. montezumae females and AtSc males of
cortezi also indicate that At and Sc segregate
independently, since many hybrids exhibited
either At or Sc alone, or both (Table V). Two
males appear to have been homozygous and two
heterozygous for the At gene.
There is no evidence that Sc is sex linked. In
strain 38 (Table IV), a significantly higher per-
centage of males showed the Sc pattern, but this
could result from a higher penetrance in males.
The sex ratio of strain 38 does not differ from
1:1; in fact, we have obtained a total of 458
males and 458 females (Tables III & IV), and
Kosswig (1959) reported 112 males and 112
females. Zander (1965) has recently suggested
that two types of males occur in X. m. cortezi.
He obtained males that sired broods in which
all, or nearly all, the offspring were females, and
he believes that these males were XX fish in
which sex had been determined by autosomal
male factors. Other males, believed to be XY,
sired offspring that were 50 percent or more
male. Zander also stated that XX males are of
much more frequent occurrence in X. m. cortezi
than in X. maculatus, but offered no direct evi-
dence to support this claim. Since Zander ( 1 965 )
1967]
Kallman & Atz: Gene and Chromosome Homology in Xiphophorus
115
Table IV. Inheritance of Macromelanophore Patterns, At and Sc, in
Strain 38 of Xiphophorus montezumae cortezi
Offspring
Generation Parents ; ~ : 7~
+ Sc At AtSc
$
8
9
$
9
o+
8
9
8
Total
2
Sp 1
Sp 1
2
4
1
3
2
12
3
At Sc
AtSc
1
1
1
3
2
4
12
4
Not recorded
5
At Sc
AtSc
3
2
1 2
2
1
11
6a
At Sc
AtSc
1
5
6
6b
At Sc
AtSc
3
1
2
5
11
7b
At Sc
AtSc
6
2
8
11
27
8
At Sc
AtSc
2
7
22
31
9b
At Sc
AtSc
1
1
2
4
9c
At Sc
AtSc
7
2
3
4
16
9d
At Sc
AtSc
5
2
1
1
9
10
At Sc
AtSc
1
1
13
15
30
11a
At Sc
AtSc
5
4
9
lib
At Sc
AtSc
1
7
12
17
37
12b
At Sc
AtSc
2
2
2
6
13a
At Sc
AtSc
8
4
3
10
25
13b
At Sc
AtSc
2
1
2
5
14b
AtSc
AtSc
2
2
5
9
14c
At Sc
AtSc
4
1
6
11
15a
AtSc
AtSc
2
3
6
11
15b
AtSc
AtSc
6
7
4
17
15c
AtSc
AtSc
1
. .
1
3
5
15d
AtSc
AtSc
1
5
4
10
Total
5
3
1
2 59
25
84
135
314
Males: 165
Females: 149
1 From ped. 38
does not record the sex ratio of his stock of
X. m. cortezi and lists only the sex ratios of a
few selected crosses, without indicating how the
fish are related to one another, it cannot be de-
termined whether these crosses are representa-
tive of the species as a whole. Our sex ratio data,
for example, provide no evidence for the exist-
ence of XX males in X. m. cortezi. In only two
out of 44 crosses did the sex ratio differ signifi-
cantly from 1 : 1 (ped. 29 and 40, Table III) ; in
one there was an excess of males and in the
other an excess of females, but neither deviation
was as large as the ones reported by Zander.
Xanthophores and xanthoerythrophores are
present in small numbers in X. montezumae
(Oktay, 1964). Some males of X. m. monte-
zumae have bright orange swords, and in both
subspecies fish are found with bright yellow
Table V. Hybrids between Females of X. m. montezumae and Males of
X. m . cortezi
Pedigree
Parents
Offspring
Female
Male
At
Sc1
AtSc1
+
Of
9 8
9
8
9 8
900a
733-3
+
386-13
AtSc
7
4
7
900b
733-4
+
386-14
AtSc
4 1
6
12
900c
733-5
+
386-15
AtSc
3
3 2
5
900d
733-6
+
386-15
AtSc
3
4 3
7
12
1
1 In five females and eight males, the Sc pattern is so weakly developed it can hardly be recognized.
116
Zoologica: New York Zoological Society
[51:11
dorsal fins. Whether this red and yellow pig-
mentation is genetically homologous to the poly-
morphism found in X. variatus and X. maculatus
is not known. By means of introgressive hybridi-
zation, Myron Gordon introduced the chromo-
some of cortezi that carries the Sc gene into the
3B strain of X. hellerii strigatus. In the backcross
hybrids, the Sc pattern developed slowly and
varied greatly in its expression. In some fish the
entire caudal fin and caudal peduncle ultimately
turned black; in others only a few macromelano-
phores were present in the caudal fin at the age
of one year, and in some fish the penetrance of
the 5c gene was nil. An idea of the variability
of this pattern can be gained from photographs
in Atz (1962), Breider & Mombour (1949),
Gordon (1956a), Marcus & Gordon (1954),
and Zander (1965). Most striking in the Sc
backcross hybrids is their red body coloration.
In our laboratory no hybrid with the Sc pattern
ha's ever been seen that did not possess the red
pigmentation. During the 6th to 10th genera-
tions, produced by backcrossing red, spotted
caudal fish with 3B swordtails, 288 offspring
were obtained of which 90 were both red and
spotted caudal, 53 were red, and 145 were wild
type (non-red, non-5c). There is little doubt
that the red offspring were fish in which the Sc
gene was not expressed even though it was
present. That the sum of the red fish and the
red and spotted caudal fish (143) in effect equals
the number of wild type fish supports this view.
In his popular account of the backcross hybrids,
called the Red Jet strain because of their striking
pigmentation, Gordon (1956a) indicated that
the red coloration resulted from an enhancement
of the red stripes of X. hellerii (very weakly de-
veloped in the 3B strain), as a result of modify-
ing genes introduced from X. montezumae
cortezi. Oktay (1964) also indicated that pig-
mentation of the red stripes of X. hellerii is in-
creased after hybridization with X. montezumae,
but offered no evidence. The explanation of
Gordon and Oktay is difficult to reconcile with
the observation that no Sc backcross hybrid ever
appeared that lacked red pigmentation. Further-
more, in the tenth backcross generation, in which
there were 16 red and Sc, 18 red, and 33 +)
individuals, most of the chromosomes must have
been derived from hellerii. With the reduction
in the number of cortezi chromosomes and mod-
ifiers, a gradual return of the red pigmentation
to the one typical of the pure 3B line would be
expected. Instead, the intensity of the pigmenta-
tion remained more or less constant from the
early to the latest generations.
In a more recent repetition of Gordon’s series
of crosses, a male X. m. cortezi (14th generation
of strain 38) was mated with a female X. h. stri-
gatus, a descendant of a fish collected in the Rio
Sarabia (ped. 1377). Only three hybrids were
obtained, all red and Sc. In the first backcross
generation to hellerii (ped. 1600), 19 of the fish
were red and spotted caudal and 25 were wild
type. In the second backcross generation (ped.
1707), 35 were red and spotted caudal, two
were red only, and 44 were wild type. Red pig-
mentation and the Sc pattern were again in-
herited together, just as in Gordon’s series of
backcrosses. In contrast to Gordon (1956a) and
Oktay (1964) , we suggest that the red pigmenta-
tion of the hellerii x montezumae hybrids arises
from a specific gene of m. cortezi which is linked
to Sc. In X. montezumae cortezi, the phenotypic
effect of this gene, if it has one, has not yet been
recognized. It is possible that it exists in more
than one allelic state: one that gives rise to
intense red pigmentation in hybrids with hellerii
(the one that is present in our stock of X. m.
cortezi) and the other with no such effect. This
would account for the lack of red body pigmen-
tation in the hybrids of Kosswig (1936) and
Breider & Mombour (1949).
The existence of genes that have no visible
effect is, of course, well known in this genus.
The Sc gene is one example, although its expres-
sion is suppressed only in a certain percentage
of fish (Table IV). Other examples involving
macromelanophore genes are known from X.
maculatus. Fish with macromelanophore alleles
may show no visible pattern, and the presence
of these genetic factors may be revealed in
crosses with other populations or species (Gor-
don, 1951a; Kallman, 1965a). Similar observa-
tions have been made on the Dr gene (red dor-
sal) of X. maculatus. In hybrids with variatus,
hellerii, and couchianus, not only the dorsal fin
is red, but almost the entire body of the fish from
the level of the dorsal fin backwards (Kosswig,
1937, 1948, 1959, 1961; Gordon, 1948, 1950b;
Atz, 1962; Zander, 1962). In crosses with mon-
tezumae and pygmaeus, however, the expression
of Dr is suppressed completely (Kosswig, 1961;
Zander, 1962). Powerful genetic mechanisms
are evidently present, mechanisms that hold the
expression of pigment patterns within a norm
in a given population or gene pool. It is not
difficult to visualize how such a genetic system
could evolve further so that finally the gene has
no visible effect in any member of the popula-
tion, although it may retain other important
functions. Only when such a genetic mechanism
is destroyed through out-crossing will the pres-
ence of such a gene be demonstrated.
If our interpretation of the red coloration in
X. m. cortezi— X. hellerii hybrids is correct, cor-
1967]
Kallman & Atz: Gene and Chromosome Homology in Xiphophorus
117
Table VI. Inheritance of Macromelanophore Pattern, Db1, in a Strain of
Xiphophorus hellerii guentheri
Pedigree
Parents
Offspring
Female Male
DM
+
9
$
Immature
9
$
Immature
Bx-1
Db*
Bx-12
+
16
19
15
26
Bx2
Bx-2
+
Bx-1 1
DM
8
4
7
11
BxTd)
Bx6-1
Db1
BxMl
DM
8
33
3
5
BX8-17(2)
Bx
Db i
Bx
DM
170
292
10
321a
3B9-1
+
Bx-1 1
DM
18
20
35
23
321b
3B9-2
+
Bx-14
DM
7
9
12
11
323
Cx-2
+
Bx-1 3
DM
8
7
12
9
481 <3)
Bx
DM
Hx-11
DM
6
12
5
5
488
Bx2-2
DM
Hx-13
+
10
11
24
4
6
24
< 1> Offspring of third through sixth generation not recorded.
<2> Summary of 15 crosses involving 10 generations.
<3> Eleven of the 18 fish that were examined exhibited Db2.
tezi represents the third species in which a gene
controlling pigmentation by erythrophores is
linked to a macromelanophore locus.
e. Xiphophorus hellerii.
In several populations of X. h. guentheri and
X. h. strigatus, a small proportion of fish exhibit
macromelanophore spotting (Rosen, 1960, pg.
120, 125, 126). The pattern that is present in
the Bx strain has been described by Atz ( 1962) .
This pattern (Db1) is dominant, autosomal, and
its penetrance appears to be 100% (Table VI;
Fig. 9). 9 The two wild-caught spotted fish were
undoubtedly heterozygous for this allele, since
when they were mated to wild type individuals,
both spotted and non-spotted fish appeared in
equal frequency among the offspring. A mating
of two spotted fish with each other gave rise
to 41 spotted and eight non-spotted individuals,
a ratio that does not differ significantly from
the expected 3:1. Inbreeding Db 1 fish brother-
to-sister for 10 generations has produced the
Bx strain. Fifteen crosses resulted in 170 females
and 292 males, all spotted. When a spotted
swordtail of the inbred Bx line was outcrossed
to a wild type X. hellerii, the offspring (14 fe-
males, 17 males) were all spotted. The Bx strain
must be homozygous (Z)MZ)M).
A second stock of swordtails with a spotted
pattern can be traced to fish collected by Myron
Gordon in the Rio Lancetilla, Honduras (see
Fig. 10) . This stock, Hx, was bred in our labora-
9 Designated Db1 for dabbed, which refers to the
irregular size and shape of the spots (Atz, 1962). This
factor was called Sp by Atz (1962). The evidence for
incomplete penetrance mentioned by this author does
not exist.
tory for only four generations, but its descend-
ants are still maintained in the laboratory of
Dr. Curt Kosswig in Germany. The pattern in
the Hx strain is controlled by an autosomal
dominant gene that shows 100% penetrance in
the Hx stock and in Fi hybrids with other strains
of swordtails (Table VII). In the Hx fish, as
pointed out by Rosen (1960, p. 126), the spots
show a tendency to be arranged in rows, es-
pecially in older specimens. Fish with this more
or less striped pattern have been illustrated by
Zander (1962, Table III, Fig. 3) and Peters
( 1964, Fig. 5) . Only 20 of our Hx fish have been
preserved and of these, 19 have the striped ar-
rangement of macromelanophore spots on at
least some part of their flanks. This pattern is
clearly different from the spotting of the Bx
strain. Of 55 Bx fish examined, only 10 had small
stripes, and these were irregular and never in-
cluded more than four spots, thus being unlike
the Hx stripes which in many cases are com-
posed of eight to ten spots. Several crosses sug-
gest that the difference in the spotted patterns
of the Bx and Hx lines do not result from modi-
fying factors, but from different genes. In pedi-
gree 488 (Table VI) in which the Db 1 gene was
introduced by the Bx line, none of the spotted
offspring showed stripes, whereas in pedigree
481 in which both parents introduced genes for
spotting 11 of the 18 fish examined showed a
striped pattern. We have also examined 3 1 avail-
able Fi hybrids of Gx x Hx and Cd x Hx, and
18 of these had spots arranged in horizontal
rows. The remaining 13 fish were small and
weakly spotted. In contrast, only two of 41 avail-
able Fi hybrids of Cx x Bx or 3B x Bx showed
any tendency towards an arrangement of their
118
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Table VII. Inheritance of Macromelanophore Pattern, Db 2, in a Strain of
Xiphophorus hellerii guentheri
Pedigree
Parents
Offspring
Female
Male
Db 2
+
9
$
Immature
$
S
Immature
Hx-1 +
Hx- 1 1
Db 2
8
5
21
13
5
13
Hx2
Hx-2 +
Hx-1 2
Db 2
14
14
14
15
8
13
Hx3-a
Hx2-1 Db 2
Hx2-ll
Db 2
3
4
1
3
Hx3-b
Hx2-2 Db 2
Hx2-12
Db 2
7
3
3
422
Cd2-4 +
Hx-14
Db 2
11
8
7
13
824
Gx +
HxMl
Db 2
10
14
1
825
3B16 +
HxMl
Db 2
28
481<i)
Bx Db i
Hx-1 1
Db 2
6
12
5
5
482
481-1 Db
481-11
Db
11
9
57
3
4
16
483
482-2 Db
481-12
Db
7
10
1
4
W In pedigrees 481, 482, and 483, Db1 and Db 2 were not distinguished. These crosses indicate that both pat-
terns are inherited as autosomal dominants.
spots in stripes. The macromelanophore patterns
of the Bx. and Hx strains show consistent differ-
ences that are maintained in hybrids. In our
opinion, they are caused by • different genes,
which we designate Db 1 and Db2, although no
critical experiment has yet been performed to
determine whether or not they are alleles.
The problems that can arise with a Xipho-
phorus of indefinite ancestry or uncertain geo-
graphic origin are well illustrated by the history
of the montezuma (Mo) factor. Kosswig was
the first to show that the orange or orange-red
coloration and the numerous black spots of the
so-called montezuma swordtail were inherited
together and behaved as if controlled by an
autosomal dominant gene, which he called Mo.
Following the views of a leading aquarist, Chris-
tian Briining, Kosswig (1933, 1934) believed
that this factor had originated from a pair of
X. montezumae that had been imported into
Germany just before the first World War and
that it had been perpetuated by twenty years of
backcrossing to aquarium stocks of X. hellerii.
When the first living X. montezumae cortezi
were imported, however, it was apparent that
the pigmentation of this species bore no resem-
blance to the montezuma pattern (Gordon,
1938), and Kosswig (1935b, 1937) then sug-
gested that Mo was most likely a gene belonging
to X. hellerii. Breider (1936) reported that a
fish with pigmentation identical to Mo had ap-
peared among the offspring of a mating between
a wild type and a red swordtail. He supposed
this to be a mutant but was unable to test it be-
cause the fish was sterile. Nevertheless, Breider
(1936) and Kosswig (1936) both recognized
the possibility that some other species of Xipho-
phorus might have been the source of Mo.10
Gordon (1943, 1948) found he could reproduce
the montezuma pattern by hybridizing X. macu-
latus that carried the factors for striped and red
dorsal (Sr Dr), with X. hellerii and then back-
crossing the Fi to hellerii. He concluded that
Mo is “probably homologous” with Sr and Dr
and that the montezuma variety of swordtail
was of hybrid origin. Breider (1949), Kosswig
& Oktay (1955), and Oktay (1964) agreed with
this view. There seems to be no question of the
hybrid origin of the so-called montezuma sword-
tail, especially when it is noted that no specimens
with Mo, or any pigmentation at all like it, have
ever found among the thousands caught in na-
ture. The Sr and Dr must have been closely
linked in the platyfish progenitor of the monte-
zuma variety— as they are known to be in the
strain Jp 30 in our laboratory.
At least two other genes for color patterns
of unknown origin have been recorded in X.
hellerii, viz. seminigra (Sn) and rubescens (Rb),
10 Kosswig & Sengiin (1945) suggested that the spe-
cies described by Ahl (1938) as Xiphophorus pseudo-
montezumae was most probably the form from which
Mo was introduced into X. hellerii through hybridiza-
tion. Breider (1938) had previously indicated that this
fish, which was then still undescribed, might have been
the source of Mo. Indeed, the specimens were undoubt-
edly among the first so-called X. montezumae that
turned up in Germany before the first World War
(Ahl, 1938). The two specimens upon which Ahl based
his description give every evidence of being hybrids,
however, most likely between X. maculatus and X. hel-
lerii, but possibly between X. v. variatus and X. hellerii.
Ahl gave the type locality simply as Mexico, no more
exact information being available. We are convinced
that some home aquarium was the real place of origin.
1967]
Kallman & Atz: Gene and Chromosome Homology in Xiphophorus
119
the former characterized by black pigmentation
on the lower half of the body and the latter by
a red coloration that commences at the base of
the tail and covers most of the body (Breider,
1938; Kosswig, 1939). As with the montezuma
(Mo) pattern, no wild swordtail with pigmenta-
tion resembling Sn or Rb has ever been seen.
The hybrids between X. maculatus with red col-
oration and X. hellerii show an extension and
intensification of the red, and this effect becomes
more pronounced in backcrosses to hellerii. Un-
doubtedly the red swordtails of commerce owe
their color to genes of X. maculatus that have
been introgressively incorporated into their
genomes (Gordon, 1943, 1946b, 1948). Koss-
wig (1961) and Oktay (1964) came to the
conclusion that Rb was a maculatus gene intro-
duced into domesticated swordtails.
2. The Micromelanophore Tail Patterns.
a. Xiphophorus maculatus.
The morphology, genetics, and geography of
the tail patterns of X. maculatus have been
studied by Gordon (1931, 1937b, 1946b, 1947b,
1956b), Gordon & Fraser (1931), Gordon &
Gordon (1950, 1957), and Kerrigan (1934).
Gordon recognized seven basic pigment patterns
in addition to the unmarked wild type, and he
showed that they were members of a single
autosomal, dominant allelic series (Gordon &
Fraser, 1931; Gordon, 1947b). Up to the pres-
ent, no fish with more than two of these patterns
has been recorded, either from nature or the
laboratory (Rosen, 1960, pg. 76). Whether four
other tail patterns that are rarely seen— upper
and lower comet, axhead, and cut-crescent— also
belong to this allelic series is not known.
New evidence indicates there are two distinct
tail patterns that were previously lumped under
the category of “one-spot”. One of these pat-
terns, O, is present in homozygous condition in
the Jp 30 strain and is identical in its morphology
with the pattern described as one-spot by Gordon
(1931) ( see Fig. 6 ) . Several photographs of fish
possessing this pigmentation have been published
(Gordon, 1947a; Gordon, 1951b, the male in
fig. 4; Gordon, 1952, fig. 2, plate 1; Gordon &
Gordon, 1957, the female in fig. 4, plate 2;
Sterba, 1 963, the female in fig. 760) . A distinctly
different pattern, which we call dot (D) because
of its small size, is present in the A and B lines
of Jp 163, both of which are homozygous for it.
Photographs of fish possessing dot may be found
in Gordon & Gordon (1957, the females in
plate 1, figs. 1 and 3), Kallman & Gordon
( 1958) , MacIntyre (1961b) , and Sterba ( 1963,
the male in figs. 760 and 761). Differences be-
tween the two patterns are readily apparent even
in newborn fish. One-spot is then visible as a
small black area, while dot does not develop until
later on. In specimens six months old or older,,
the one-spot pattern covers the entire hyplural
bone except for its most anterior apex. As Gor-
don (1931) pointed out, the posterior margin
of this pattern coincides with the part of the
hyplural bone with which the caudal fin rays
articulate. Although the dot pattern occupies a
similar position and shows considerable varia-
tion, it is always less than half the size of the
one-spot. It is slightly irregular in outline and
consists typically of two narrow, intensely black
lines of pigment cells that occur just above and
below the horizontal septum, which divides the
fish along the midlateral line into dorsal and
ventral halves. These bands of pigment cells run
anteriorly approximately one half the length of
the hyplural bone. The posterior margin of the
dot coincides with that of the one-spot. A narrow
band of pigment cells is often present just an-
terior to the articulation of the caudal fin rays
with the hyplural bone in dot, but the pigment
cells do not extend as far dorsally or ventrally
as in one-spot. Especially in older, more heavily
pigmented fish, pigment cells may completely
fill in the angles formed by the horizontal and
vertical components of the dot pattern, giving
it a somewhat triangular appearance. In small
fish, the one-spot pattern may be similar in size
to the dot in larger fish, but the difference in
shape is always present. Fish that are heterozy-
gous for the two patterns look like those with
one-spot alone.
Both patterns have been called “one-spot” in
the past and treated as if they were caused by
the same allele.11 If this is true, the difference
in phenotypic expression must be the result of
modifying genes. But when fish belonging either
to strain Jp 30 or Jp 163 were outcrossed to
other stocks of X. maculatus or to other species,
the integrity of the dot and the one-spot patterns
was maintained in every case. Of the many
crosses that demonstrate one-spot and dot to be
controlled by different alleles, two are described
here. In the first backcross generation of (Jp
30 x X. couchianus) x X. couchianus, all fish
that inherited the tail spot pattern from the Jp
30 strain were typically one-spot in appearance,
although the overall intensity of the pigmentation
was much greater than in the pure species (Table
VIII, ped. 1095, 1161, 1166). On the other
hand, in the first and second backcross genera-
tions of (Jp 163 x X. couchianus) x X. couchi-
anus, all fish with the tail spot pattern possessed
uFor example, by Gordon (1943, 1947b), Rosen
(1960), and Atz (1959).
120
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Table VIII. Inheritance of Tail Spot Patterns in Xiphophorus maculatus
(Phenotypes Only Indicated)
Pedigree
Parents
Offspring
Female
Male
O
D
Cc Cc O
CcD
+
DT
1095
C-30
O
Xc-G
+
16
1161
1095-1/2
O
Xc-G
+
33
45
1166
Xc-G
+
1095-11
O
6
4
845
Jp 163B
D
Xc-G
+
34
881
845-1/2
D
Xc-G
+
14
9
945, 946
88I-V2
D
Xc-G
+
7
8
270
Jp-30
O
Cp-11
CcD
100
2702
270-2
CcO
270-12
CcO
12
21
11
292
270-1
CcO
Cp-11
CcD
44
50
1380a, b
1342-1,2
CcD
Jp 163B
D
48
46
1500
1380a-l
CcD
Cp
+
102
99
1923
1900-21
CcO
Hp-2
T
26
30
the dot pattern, although the expression of the
D allele was also enhanced in the hybrids (Table
VIII, ped. 845, 881, 945, 946; Fig. 2).
Three apparent exceptions to the rule that no
platyfish can inherit or possess more than two
tail patterns (as is required for true allellism)
have been encountered. The first case involved
a male platyfish (Cp-11), collected in 1948 in
the Rio Coatzacoalcos. This male, which had the
complete-crescent and dot patterns, was mated
to a female of strain Jp 30 homozygous for one-
spot (see Fig. 6). All of the 100 offspring ex-
hibited the one-spot and the complete-crescent
patterns (Table VIII, ped. 270; Fig. 7). Despite
its phenotype, the male parent must have been
homozygous for the Cc allele. When one of the
Fi females was backcrossed to Cp-11, one half
of the offspring exhibited the one-spot and com-
plete-crescent patterns and the other half the
dot and complete-crescent (ped. 292). When
two Fi fish were mated, 50% of the F2 were
complete-crescent and one-spot, and 25% were
complete-crescent and dot, and 25% were one-
spot (ped. 2702). These results can be explained
by recalling that one-spot, dot fish are pheno-
typically identical with one-spot fish and by
assuming that dot and complete-crescent were
inherited together:
CcD Cc (male) x O O (female)
O CcD complete-crescent, one-spot (50% Fi)
O Cc complete-crescent, one-spot (50% Fi)
O CcD x O CcD
O O one-spot (25% F2)
O CcD complete-crescent, one-spot (50% F2)
CcD CcD complete-crescent, dot (25% F2)
A similar case was discovered in 1963. Five
fish that had been collected in the Rio San Pedro
at Carmelita, Guatemala, exhibited both Cc and
D. Two females were mated to Jp 163 B (DD)
males in order to determine the constitution of
their sex chromosomes (Kallman, 1965a). As
expected, all the offspring (Table VIII, ped.
1380) showed dot and one half of the fish
showed complete-crescent. One Fj female (CcD)
was mated to a male of the Cp (Coatzacoalcos)
strain, which does not possess any tail spot pat-
terns. One half of the offspring of this cross in-
herited dot, the other half complete-crescent and
dot (ped. 1500). Again, the results can only be
explained by the assumption that in the fish from
Carmelita, Cc and D are inherited together. The
detection of complete-crescent linked to dot is
difficult because the same pattern results when
Cc and D are on different chromosomes and
when dot is masked by the one-spot or moon
patterns. The pattern complete-crescent without
dot, as described by Gordon (1931), is present
in the homozygous condition in the Hp— 1 line
(see Fig. 8). When fish of this strain are out-
crossed to other platyfish stocks, the offspring
show Cc but never D, unless the latter is intro-
duced from the other stocks.
The third case came to light recently and in-
volved the inheritance together of one-spot and
complete-crescent. A female from British Hon-
duras (ped. 1900-21), that was phenotypically
one-spot and complete-crescent, was mated with
a male of the Hp-2 stock, homozygous for twin-
spot (TT). They produced 30 offspring that were
dot and twin-spot (DT) and 26 that were one-
spot and complete-crescent. Since complete-
crescent masks twin-spot, the latter had T as
1967]
Kallman & Atz: Gene and Chromosome Homology in Xiphophorus
121
well as 0 and Cc. The genotype of the female
parent undoubtedly was OCc D.
At the present time, it is not possible to decide
whether we have identified two new alleles or
whether we are dealing with a super-gene.
b. Xiphophorus variatus.
The unitary tail spot pattern (Ps) of X. vari-
atus is morphologically and anatomically dis-
tinct from the one-spot and moon patterns of
X. maculatus.12 In X. v. xiphidium it varies in
appearance from what superficially appears to.
be a small spot to a large blotch that occupies
a considerable portion of the posterior end of
the caudal peduncle (see Fig. 12). In some fish
it is bounded anteriorly by the hemal and neural
spines of the fourth caudal vertebra, which in
this species, is the most anterior one whose spines
articulate with caudal fin rays. In other indivi-
duals, the peduncular spot may extend only as
far forward as the spines of the third caudal
vertebra or perhaps not this far. Posteriorly, it
extends well into the muscles lying between the
lepidotrichia of the caudal fin, especially along
the proximal portions of all bifurcated fin rays
and one or two of the single ones immediately
above or below them. In the caudal fin, the
melanophores of this pattern occur in the muscle
fascia and around blood vessels that are located
between the lepidotrichia. In the caudal ped-
uncle, the pigment cells are heavily concentrated
in the fascia of the deep-lying muscles, around
blood vessels and nerves. This arrangement of
melanophores differs fundamentally from that
of the moon and one-spot of maculatus in which
the melanophores are primarily located in the
lower dermis and the muscle fascia immediately
below (see Figs. 14-17).
The peduncular spot (Ps) of X. v. variatus is
very similar to the pattern of the same name in
X. v. xiphidium but, at least according to the
samples available to us, there seems to be a
minor, but consistent, difference in that the pig-
mentation is less intense. The maximum size
attained appears to be the same, but there are
smaller peduncular spots in our samples of X. v.
variatus than in any X. v. xiphidium that we
have seen.
The crescent pattern (C) of both X. v. variatus
and X. v. xiphidium is identical in shape and
structure with the pattern of the same name
found in X. maculatus. The anterior margin is
bounded by the principal caudal blood vessel
12 Designated Ps for peduncular spot. Formerly called
moon (M) by Gordon (1943) and one-spot (O) by
Atz (1959) and Rosen (1960).
which bridges the caudal fin rays slightly pos-
terior to their point of articulation. The posterior
edge of the musculature of the caudal fin forms
the posterior end of this pattern. Usually all but
the most dorsal and ventral fin rays are involved.
The pigment cells are primarily located in the
inter-radial tissue, most heavily around the fin
rays themselves. In both subspecies, the intensity
of the pigmentation of the crescent may vary
considerably. In some fish the pattern is jet black
and the area behind its posterior margin is free
from micromelanophores, thus setting off the
crescent dramatically from the adjacent tissue
(see Fig. 1 ) .
The cut-crescent pattern (Ct) of X. v. xiphi-
dium and X. v. variatus occupies the same area
as the upper and lower parts of the crescent.13
The dorsal part of the cut-crescent covers from
six to nine caudal fin rays, usually beginning with
the first (uppermost) bifurcated ray and seldom
failing to include more than the most dorsal
simple ray. The ventral part covers from five
to nine caudal fin rays, usually beginning with
the second or third simple ray, counting down
from the lowermost bifurcated ray. It may in-
clude all but the lowermost one to three simple
rays. The cut-crescent pattern does not differ as
much in the intensity of its pigmentation as does
the crescent, although the area behind the cut-
crescent may also be free from micromelano-
phores. Fish of genotype C Ct can easily be dis-
tinguished from C or CC fish, since the dorsal
and ventral portions of the combined patterns
are much darker than the center, even when the
crescent pattern is rather dusky. The anterior
and posterior borders of the cut-crescent are
also much less uniform and regular than those
of the crescent. Frequently, there are extensions
of pigmentation toward the rear around each
caudal fin ray, and one, two, or three of these
may reach considerably past what would be the
posterior limit of the crescent pattern. This may
be clearly shown when cut-crescent and crescent
occur together in the same fish. Anteriorly, there
may be extensions of pigmentation, but these are
not as prominent as the posterior ones, although
they are occasionally represented by numerous
pigment cells in the deep-lying muscles of the
area.
The upper (dorsal) part of the cut-crescent
is frequently noticeably better expressed, that is,
more intensely pigmented and somewhat larger,
than the ventral one, and this tendency might be
13 Zander (1962) calls this pattern twin-spot (T).
Anders & Klinke (1965) provide a photograph of a
Platypoecilus xiphidium (— X. v. xiphidium) with cut-
crescent, which they also call twin-spot.
122
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Table IX. Inheritance of Tail Spot Patterns in Xiphophorus variatus
xiphidium (Phenotypes Only Indicated)
Pedigree
Parents
Female Male
Offspring
C Cu Ct Ps C Cu
Px-
20
Px-1
C
Px-11
+
9
22
8
27
9
3
8
13
9
8
9
8
9
8
9
8
21
Px-2
+
Px-12
Ct
12
17
5
17
22
Px-3
+
Px-1 3
Ct
4
1
3
4
23
Px-5
+
Px-1 4
c
20
16
14
5
25
23-2
c
21-11
+
5
8
4
6
26
23-3
c
21-12
Cu
4
4
6
3
6
2
9
2
27
23-4
c
21-13
+
7
2
2
2
35
26-1
C Cu
25-11
+
4
3
6
4
37
26-5
C Cu
26-11
+
12
12
12
14
43
26-6
Cu
27-11
+
2
3
4
5
36
26-4
C Cu
26-11
Cu
4
61
8i
31
5i
44
26-7
Cu
25-14
+
6
2
4
4
45
36-1
Cu 1
36-11
C«i
2
1
6
7
46
36-2
C«i
25-15
+
13
9
50
36-4
C«i
40-11
c
8
13
12
18
1251
1184-1
PsC
1228-12
+
13
13
14
12
1 Fish with a strongly developed upper crescent and a very weakly developed lower crescent.
thought to find its ultimate expression in indivi-
duals that appear to lack the ventral part entirely.
Close examination, however, has always re-
vealed slight traces of the lower element. This
might indicate that the cut-crescent and upper
cut-crescent patterns are controlled by the same
allele and represent the phenotypic expression
of modifiers. It is possible, however, that the
two patterns are controlled by two different
alleles (Ct and Cu, respectively) , because pheno-
typically a particular fish can almost always be
assigned to one category or the other, the sepa-
ration between them being marked even though
the upper cut-crescent pattern usually includes
a small ventral component.
In one series of experiments involving the
tail spot patterns of X. v. xiphidium, there are
indications that upper cut-crescent and cut-
crescent are controlled by the same allele (Table
IX). For example, a wild-caught male (Px-12)
exhibited the cut-crescent pattern, yet among
its descendants both cut-crescent and upper cut-
crescent fish appeared. The existence of genetic
factors that influnce the phenotypic expression
of cut-crescent (Ct) is indicated by the appear-
ance of certain hybrids. In a cross, involving a
female X. v. xiphidium with a normally ex-
pressed cut-crescent and a male X. v. variatus
with no tail pattern, the intraspecific hybrids
exhibited tail patterns that ranged from cut-
crescent to crescent (Atz, 1962). In a cross,
involving a male X. v. xiphidium with cut-cres-
cent and a female X. hellerii, the interspecific
hybrids exhibited crescent tail patterns instead
of cut-crescent (Zander, 1962).
c. Xiphophorus milleri
In this species three tail spot patterns are
known (see Figs. 4 & 5). Bar ( B ) is composed
of a diffuse, slightly crescent-shaped, narrow
band of melanophores located just in front of
the caudal blood vessel and the point where the
caudal fin rays articulate with the axial skeleton.
Its position, therefore, is quite different from
that of the crescent pattern in maculatus and
variatus, which is located behind the caudal
blood vessel. Moreover, the melanophores of
bar are primarily located in the dermis while
those of crescent are found mainly around the
dorsal and ventral edge of each lepidotrich. The
upper and lower limits of the bar pattern are
rather indistinct even when it is well developed.
It does not extend as far as the middorsal or
midventral lines, but usually ends at the level
of the 4th and 5th caudal fin rays. Bar often
does not make its appearance until several weeks
after sexual maturity has been attained.
Another tail spot pattern of X. milleri is point
(Pt), an intensely black pigment spot with a
slightly irregular outline, located over the hy-
plural bone and occupying the same position
as dot in maculatus. The diameter of Pt is
roughly 12-15% the straight-line distance be-
tween the middorsal and midventral lines. In fish
1967]
Kallman & Atz: Gene and Chromosome Homology in Xiphophorus
123
exhibiting both Pt and B, the point pattern is
visible in the center of the bar.
The third pattern is a single spot (Ss), which
is located in the same position as the one-spot
of rnaculatus. Single spot is twice as large as
point and covers roughly one third to one half
of the distance between the middorsal and mid-
ventral lines. As in the case of bar, the melano-
phores of single spot and point are found in the
lower dermis and superficial musculature and
are located anterior to the point where the fin
rays articulate with the caudal skeleton. Fish
that carry both the Ss and Pt alleles are single
spot in appearance. Breeding experiments show
that all three patterns of X. milleri belong to a
single dominant, autosomal allelic series (Table
II).
d. Xiphophorus montezumae and
X. pygmaeus nigrensis
In both subspecies of X. montezumae, a single
highly variable tail spot pattern has been recog-
nized, the caudal blotch (Cb). An almost identi-
cal pattern occurs in X. pygmaeus nigrensis (see
Fig. 3 and the lower male in Fig. 14 of Rosen,
1960). In all three forms, the caudal blotch
varies both in shape and intensity. In addition,
the melanophores of this pattern appear to be
under nervous control to a much greater degree
than the pigment cells of the other patterns,
since the caudal blotch may disappear and re-
appear within a relatively short period of time,
and anesthetization (with MS 222) of the fish
leads to its intensification. In many fish it is well
developed in the midportion of the tail only,
often not extending dorso-ventrally as far as the
uppermost or lowermost bifurcated caudal fin
rays. A few fish have been seen in which the
pattern was best developed along its posterior
margin, where a narrow band of pigment cells
ran dorsally and ventrally from the central black
area, roughly parallel to the posterior edge of the
caudal fin musculature. In some fish of both
species, however, the caudal blotch is strongly
developed and extends dorso-ventrally as far as
the third simple caudal fin ray, and the pattern
then superficially resembles the crescent pattern
(see Fig. 3). The two patterns are morphologi-
cally distinct, however. The melanophores that
comprise the caudal blotch are concentrated in
the dermis between the musculature and the
scales, in the scale pockets, and in the connective
tissue fascia that run at right angles from the
dermis to the upper and lower edge of each
lepidotrich (see Fig. 13). Anteriorly, the caudal
blotch borders the caudal blood vessel and pos-
teriorly it extends somewhat beyond the limit of
the musculature of the caudal fin.
e. Xiphophorus hellerii
Although many thousands of swordtails have
been collected in many different localities com-
prising all the major river systems in which the
species occurs, only the fish of the Rio Chaj-
maic, Guatemala, possess black patterns in
their caudal fins (see Fig. 11). Every swordtail
collected in this isolated population possessed
a slightly elongated pigment spot in the ventral
part of the caudal fin (Kallman, 1963). This
pattern resembles the diacritical mark, grave,
and it typically involves the first through the
fifth ventral bifurcated caudal fin rays, although
in a few fish, the first or fifth ray may not always
be included in the spot. The pigment cells that
make up the grave (Gr) pattern are located in the
connective tissue and perymysium that surround
the fin rays. Grave reaches its greatest posterior
extension along the second (rarely the first)
bifurcated caudal fin ray, and on each of the
fin rays above this, the pigmentation ends pro-
gressively more anteriorly. On the fourth or
fifth ray, for example, the pigmentation may
consist merely of a tiny group of melanophores
immediately behind the caudal vessel, with no
measurable posterior extension. The anterior
limit of the pattern is along the major caudal
blood vessel, although a few pigment cells may
also be found between this vessel and the point
of articulation of the fin rays with the axial
skeleton. The pattern makes its first appearance
in fish that are two to three weeks old. In males,
grave eventually becomes the black dorsal mar-
gin of the caudal sword. Swordtails from the
Rio Chajmaic were established in the Genetics
Laboratory (Ch strain) in 1963 and are now in
the fourth generation. Seven matings have pro-
duced 22 males and 205 females, all of which
exhibited this pigment pattern.
3. Chromosome Homology.
a. Chromosomes with Macromelanophore
Patterns.
The sex chromosomes of X. v. variatus, X. v.
xiphidium, and X. rnaculatus are homologous
with one another. In one cross, a female hybrid
of variatus x xiphidium (h-2), carrying the P 1
of variatus and FI 1 of xiphidium was crossed with
a wild type couchianus x rnaculatus hybrid.
Eleven offspring (h-28) inherited P1 and eleven
others inherited Fll. None of the offspring was
wild type or exhibited both patterns. In a second
cross, a male Fi rnaculatus x v. variatus hybrid,
with the Sp of rnaculatus on its X chromosome
and the P 1 of variatus on its Y, was backcrossed
to a wild type variatus. The offspring (h-61)
consisted of 32 Sp females, one Sp male, 40 Pl
males, one P1 female, and one wild type male
124 ,
Zoologica: New York Zoological Society
[51:11
(Atz, 1962, figs. 4-6). 14 The exceptional wild
type male was not used in further matings, but
it was probably the result of non-expression of
the P1 gene. The offspring with the P1 pattern
were sparsely marked; e.g., one punctatus off-
spring possessed only six macromelanophores
on one side and none on the other. A third cross,
reported by Oktay (1962), also demonstrates
that the X chromosome of maculatus and the Y
chromosome of xiphidium behave as homolo-
gous chromosomes.
The sex chromosomes of maculatus are also
homologous with those of milleri. When an F i
hybrid of maculatus x milleri, carrying the X
chromosome of maculatus marked either by Sp
or Sd and the Y chromosome of milleri marked
by Sv, was backcrossed to a wild type female of
X. milleri, the offspring inherited either the
macromelanophore gene of maculatus or milleri,
but never both of them or neither one (Table X).
Breider & Mombour (1949) reported crosses
between X. montezumae cortezi with the Sc
pattern and X. hellerii obtained from a com-
mercial source and of unknown history. One of
their hellerii had a striking red body pigmenta-
tion that Breider & Mombour attributed to the
gene Rh (rubescens) of the swordtail. No such
gene is known to be present in this species, how-
ever, and it must have been introduced into
their swordtail stock through prior hybridiza-
tion with some other Xiphophorus, most likely
X. maculatus. Most interesting is that when one
of the Sc Rb hybrids was mated to a wild type
swordtail, the Sc and Rb genes segregated. Forty
of the offspring were red and thirty-one were
spotted caudal. According to these results, the
Sc gene of X. m. cortezi is located on a chromo-
some homologous to one of another species of
Xiphophorus, carrying Rb. If, indeed, it should
turn out that Rb is a gene from X. maculatus and
is a member of the sex-linked multiple allelic
14 The numbers given by Atz (1962) in the caption
for fig. 6 are incorrect.
series governing erythrophore and xanthophore
pigmentation, the experiment of Breider &
Mombour would indicate that the chromosome
of X. montezumae cortezi carrying Sc is homo-
logous to the sex chromosome of X. maculatus.
This cross should be repeated with fish of known
ancestry.
The chromosome of X. hellerii guentheri (Bx
strain) that carries the macromelanophore allele
Db 1 is not homologous with the sex chromo-
somes of X. maculatus (Gordon, 1958). When
hybrids possessing the Db1 of hellerii and a
macromelanophore gene of X. maculatus were
crossed to wild type fish, four classes of offspring
were obtained: 67 were wild type, 74 showed the
spots from hellerii, 37 exhibited only the macul-
atus macromelanophore pattern, and 28 fish
possessed the pigment pattern of both species
(Table XI). There is also evidence that the Db 1
of hellerii and the tail spot locus of X. maculatus
are not located on homologous chromosomes
(Table XI).
b. Tail Spot Patterns.
Two crosses suggest that the loci for tail pat-
terns of X. maculatus and X. v. xiphidium are
located on homologous chromosomes. A female
F i hybrid of X. maculatus x X. v. xiphidium
(h-20) possessing the comet pattern (Co) of
maculatus and the crescent (C) of xiphidium was
mated to a wild type male of the latter species.
The backcross generation (h-30) consisted of
30 Co, 5 C and 4 wild type offspring. In a similar
second cross, a male F i hybrid between X.
maculatus and X. v. xiphidium (h-20) carrying
Co C was mated with a female hybrid between
X. v. variatus and X. v. xiphidium that had no
tail patterns. The offspring (h-38) consisted of
57 Co, 16 C and 8 wild type fish. Since no fish
that exhibited both the Co and C patterns ap-
peared among the offspring of the two crosses,
we conclude that the tail spot locus of X. v.
xiphidium is located on a chromosome homolo-
gous to the one carrying the tail spot locus of
X. maculatus. The 12 exceptional wild type fish
may be explained by the late development of the
Table X. Tests for Homology of Sex Chromosomes of Xiphophorus maculatus
(Gp) and X. milleri
Pedigree
Parents
Offspring
Female
Male
Female
Male
1781
Gp
X^P
Xsd
1717-11
X+
Ys.
Sp Sd
25 36
Sv
Sv
Sp 5v
35
SdSv
35
1858
1748-4/5
x+
X+
1781-11
Xs,
Ysv
37
i
31
1863
1748-6/7
X+
X+
1781-12
Xs,
Ysv
31
45
Table XI. Tests for Allelism of Db 1 of Xiphophorus hellerii (Bx) and Sd, Sr, and O of X. maculatus
1967]
Kallman & Atz: Gene and Chromosome Homology in Xiphophorus
125
_|_ On *— < • <N i/^
_|_ O • • •
Table XII. Inheritance of Sex and Pigment
Patterns in Fi Hybrids of
Xiphophorus maculatus and X. milleri
X. milleri $
Pi
X. maculatus $
1401
Hp-2
X,X+Ss +
X+Ysi T T
Fi
(ped.
1532)
X+YSd
TSs
(23 55)
x+x.
TSs
(7 $2, 11 55)
X+Ysd
T +
(1955)
x,x+
T +
(6 $2, 9 55)
as
O
-o
Q
O ■ •
O <N
+ '
03
Q*
<0
Si
Q
^3
C/3
O • • (N
u • •
^ vu i l ri
+ : :
_|_ • • • to to
JJ
+ + o+ +
to
^3
to
Q + Q
Cu Cl, ^
^ PQ t"-
o o
o
*03
E
0)
Ph
O O
c. v.
Oo 00
tH t— I
-C>
Q Q
+++
+ $i +
-o
Q
~ _g
a "3
"3 Vj
5 S
2 5
j * ^
^ X CD
X ^ ^
^ 52 x
52 C to
2 3 3
OX)
*3
^ to
00 00 .
CO fO 1
VO ^
00 CN
^ Tj-
CO (N H
vo vo
^ ^ d
* m *
CQ X
crescent pattern, since many of these fish were
sacrificed soon after they had reached sexual
maturity. Even if these 12 fish were added to
the C offspring, however, there would still re-
main a large unexplained excess of Co indi-
viduals.
There is more conclusive evidence that the
genes for the tail spot patterns of X. maculatus
and X. milleri are located on homologous
chromosomes. A female X. milleri , heterozygous
for single spot (Ss), was mated to a male of X.
maculatus, homozygous for twin-spot (T) (Table
XII) . Six of the Fi hybrids (SsT) were then back-
crossed to wild type fish of either species (Tables
XIII, XIV). Of 476 backcross hybrids, 224 fish
showed single spot and 249 twin-spot, one fish
exhibited both patterns, and two possessed none.
These results are in good accord with the as-
sumption that the tail spot loci of the two species
are on homologous chromosomes that segregate
during meiosis.15
The exceptional backcross male (1587-11)
that exhibited both the single spot and twin-spot
patterns, was mated to two wild type females of
X. milleri. In the second backcross generation to
X. milleri (Table XV), 19 fish exhibited no
tail patterns, 45 fish were single spot, 35 were
twin-spot and 8 fish showed both patterns. This
result rules out the possibility that Ss of milleri
and T of maculatus had become linked on the
same chromosome as a result of crossing over.
The exceptional SsT male of the first backcross
15 Among the hybrids involving X. milleri and the
Hp-2 strain of X. maculatus, a large number of fish
with two X chromosomes differentiated into functional
males (Table XII). Some of these XX males became
sexually mature before their XY sibs. In a second
series of hybridizations involving the Gp strain of X.
maculatus, all the XX fish developed into females
and all but one of the XY fish into males (Table X).
These crosses well illustrate the difficulty that may be
encountered in using data from hybridizations to explain
sex-determining mechanisms in Xiphophorus.
Table XIII. Test for Allelism of Tail Spot Patterns of Xiphophorus maculatus and X. milleri
(Back-cross to maculatus, Gp)
126
Zoologica: New York Zoological Society
[51:11
W r
to
T3
to H N
O.CO
to
JO
S
£^2
Tt n >0
to N -h is ->
J3
ft
05 ON « >0
Co to) >— 1 (N *- 1 1
60
c
-a ,
to +
O
ft,
m K
”<3
E
i)
Ph
rft ■o
to in
13 , 0O <N
to h <N
to to *N
f-t f-t -)-
>4 >H
+ + §
^ *
<N <n
fn a
220
++
cd
E
<U
P-4
os m +
N N N
a ft
O O -
eo
•o
ro >0 —c
O O ON
CO CD CO
generation could have resulted from nondis-
junction that occurred during oogenesis in its
Fi parent. If this is the case, the offspring of the
exceptional SsT male should consist of four
classes of offspring in the following frequencies:
16.6% wild type, 16.6% showing both patterns,
and 33.3% each showing single spot or twin-
spot. The observed result differs little from the
theoretical ratio (Table XV). The deviation can
probably be explained by the abnormal segrega-
tion that would be expected in a fish that is a
species hybrid as well as trisomic. Presumably,
the two exceptional wild type offspring of pedi-
gree 1691 (Table XIII) represent a correspond-
ing nullosomic class.
IV. Discussion
The most detailed and extensive analyses of
gene and chromosome homologies in macroor-
ganisms have been made with the genus Droso-
phila, and workers with these flies have provided
the best discussions of methods, criteria, and
pitfalls (Spencer, 1949; Patterson & Stone, 1952,
pg. 261, 541; Dobzhansky, 1959). Homologous
chromosomes are those similar enough to under-
go synapsis during meiosis even in a hybrid,
and a basic, but neither essential nor sufficient,
criterion for homology between genes is that
they lie on homologous chromosomes. That the
loci for two similar series of multiple alleles, be-
longing to different species, can be shown to lie
on homologous chromosomes is considered
especially strong evidence for the homology of
the two loci. Nearly as strong is the case in which
single, phenotypically identical, or nearly iden-
tical, mutants are found to be located on homolo-
gous chromosomes. If two mutants are only
somewhat similar, the fact that they are located
on homologous chromosomes may nevertheless
indicate they are homologous. Mutants that oc-
cupy non-homologous chromosomes can only
questionably be considered homologous, how-
ever, even though their phenotypic manifesta-
tions seem to be identical, unless they can be
shown to belong to two similarly arranged
groups of genes, one of which has presumably
become relocated by translocation. In the ab-
sence of such detailed linkage maps, association
with similar arrangements of only a few genes
may serve to make homology more probable,
especially when there are numerous chromo-
somes in the genome. Among the species and
subspecies of fishes belonging to the genus
Xiphophorus, the evidence for gene homology
carries all these degrees of weight.
Kosswig (1948, 1961) has discussed gene
homology in Xiphophorus, especially in relation
to evolutionary parallelism and convergence.
1967]
Kallman & Atz: Gene and Chromosome Homology in Xiphophorus
127
Table XIV. Test for Allelism of Tail Spot Patterns of Xiphophorus maculatus and X. milleri
(Backcross to milleri)
Parents
Offspring (phenotypes)
Pedigree
Female
Male
Females
Males
+ + Sd Sd Sv Sv 5v + +
Ss T Ss T Ss T SsT SS T
1587 1532 X+ X+ Ss T 1410 - X+ Ya» + 13 11 .... 14 22 1 2 2
1604a 1410 X+ + 1532-12 X+ Ysd Ss T 2 2 4 3 1 . .
1604b 1628 X+ X+ + 1532-12 X+ Ysd Ss T 20 19 10 21 1 ..
1606 1544 X+X+ + 1532 - X. X+ Ss T 22 28 11 12
The sex chromosomes of Xiphophorus macu-
latus, X. variatus, and X. milleri are homolo-
gous with one another, since they segregate con-
sistently in Fi hybrids. They possess similar,
most probably identical, gene loci; in all three
species, the macromelanophore locus is sex-
linked, and in maculatus and variatus, this is
linked to a second locus controlling red and
yellow pigmentation of body and fins.
Kallman (1965a) recognized that the X and
Y chromosomes of X. maculatus and X. variatus
are homologous with similar genes, and he point-
ed out that this situation provides very strong
evidence for the possession of sex chromosomes
by the ancestral form of the two species. That
the gonosomes of X. milleri also are homologous
strengthens this point of view; presumably, the
sex-chromosome mechanism of all three species
had a common origin in an ancestral form with
an XX-XY (male heterogametic) system. Sex de-
termination, according to the XX-XY scheme,
is present today in X. milleri and X. variatus,
but in X. maculatus it has evolved further. In
this species three types of females (WY , WX,
XX) and two types of males (XY, YY) occur.
It has been suggested that populations with the
XX-XY (male heterogametic) and WY-YY (fe-
male heterogametic) mechanisms were geo-
graphically segregated and that the two systems
evolved independently from each other from a
Table XV. Test for Nondisjunction in a Backcross Hybrid of Xiphophorus
maculatus X X milleri
Female
+ (4)
T (13)
Ss (16)
SsT (2)
Sv +
Sv T (1)
Sv Ss
Sv Ss T (1)
Parents1
1628-1 + + 9
1602-1 + + $
1587-11 Sv SsT $
Offspring (ped. 1745)
Male
+ (4)
T (2)
Ss (10)
SsT
Sv+ (It)
Sv T (19)
Sv Ss (19)
Sv Ss T (5)
Phenotypic classes
+
5s
T
Ss T
Total
Expected
17.8 (16.6%)
35.6 (33.3%)
35.6 (33.3%)
17.8 (16.6%)
107
Observed
19
45
35
8
107
(Obs.— Exp.)2
0.1
2.7
.01
5.4 2 = x2 =
= 8.3
Exp.
n = 3. p = 0.05 > 8.3 > p -
0.01.
1 See Table XIV for origin of male parent.
128
Zoologica: New Y ork Zoological Society
[51:11
polygenic condition (Gordon, 1952; Anders &
Anders, 1963). This explanation is now unten-
able, however, in view of the chromosome
homologies discussed above and the discovery
that W and X chromosomes are found together
in the same population (Kallman, 1965a). It
would have been a remarkable coincidence in-
deed, if the same pair of autosomes (out of the
24 available pairs) had evolved into sex chromo-
somes independently in the three species, and
that during this evolutionary change the chromo-
somes had diverged so little that they maintained
their specific pairing affinity during meiosis.
None of the macromelanophore alleles of X.
maculatus, X. variatus, and X. milleri is identi-
cal, since each produces a different pigment
pattern and, as far as known, these differences
are maintained and often accentuated when
the alleles are introduced into the genomes of
other species or subspecies by means of intro-
gressive hybridization. The different patterns
cannot be primarily the result of different genetic
backgrounds. The At and Sc genes of X. monte-
zumae cortezi are not allelic and there is no evi-
dence that they are sex linked. No critical ex-
periment has yet been published that would test
the possibility that the At or Sc is located on a
chromosome homologous with the sex chromo-
some of X. maculatus, X. variatus, or X. mil-
leri.10 At the present time, it is also not possible
to determine whether the loci for At and Sc, ,
which are evidently located on different chromo-
somes, are homologous with each other and
perhaps also to the macromelanophore genes
of the other species of Xiphophorus. Since there
is evidence that the macromelanophore alleles
of X. maculatus represent a super-gene (Gor-
don, 1937a; MacIntyre, 1961c), it is possible
that some of the closely linked macromelano-
phore loci have become separated through
translocation during the course of evolution and
are now situated on different chromosomes. An
alternate possibility, of course, is that the loci
of At and Sc in X. m. cortezi are of independent
origin. Similar considerations apply to the spot-
ting of X. hellerii. This locus may be homo-
logous to the macromelanophore genes of other
species, even though it is not now located on
a chromosome that is homologous with the sex
chromosomes of X. maculatus.
All available evidence indicates that the tail
spot patterns of X. maculatus, X. variatus, and
X. milleri are also controlled by homologous
genes. As is the case with the macromelano-
10 There is evidence, however, indicating that Sc may
be located on a chromosome homologous with the sex
chromosome of X. maculatus (see page 124).
phore patterns, it is unlikely that the tail spot
genes in the three species would have arisen
independently on the same pair of chromosomes
—all of which are homologous, pair by pair,
since all of them segregate in Fi hybrids during
meiosis. There can be little doubt that the pro-
genitor to which all three species could ulti-
mately be traced already possessed the tail spot
locus. There is no evidence yet whether the
caudal blotch patterns of X. montezumae and
X. p. nigrensis are homologous with each other
or with the tail spot loci of other platyfish.
In some species or subspecies, tail spot pat-
terns occur that are almost identical in appear-
ance and these are perhaps controlled by identi-
cal alleles. This can only be established with
certainty by comparing the phenotypic effect of
the alleles against an identical genetic back-
ground. Strikingly similar are the one-spot of
maculatus and the single spot of milleri; the dot
of maculatus and the point of milleri; the simple
crescent of maculatus, v. variatus, and v. xiphid-
ium; the caudal blotch of montezumae and p.
nigrensis; and the upper cut-crescent, cut-cres-
cent, and peduncular spot of v. variatus and v.
xiphidium. In contrast, patterns unique for one
form are the moon, moon complete, comet, and
complete-crescent of maculatus and the bar of
milleri.
There is as yet no answer to the question why
certain patterns are widespread while others
occur only in single species or are absent from
certain populations of others. Although there are
exceptions, the species, subspecies, or popula-
tions of Xiphophorus with relatively restricted
ranges are less polymorphic, as Gordon (1943)
pointed out. Neither macromelanophore nor tail
spot patterns are known from the two subspecies
of X. couchianus or from X. p. pygmaeus. In
X. p. nigrensis, only a single tail spot pattern
occurs, and in X. v. evelynae, only one macro-
melanophore pattern. These forms all occupy
limited areas, especially as compared with X.
maculatus, X. v. variatus, X. v. xiphidium, and
X. hellerii (see Text-fig. 1, Table XVI) .
According to Gordon & Gordon (1957), the
simple crescent and comet patterns are absent
from the populations of X. maculatus inhabiting
the Rio Usumacinta (which lies at the center
of this species’ distribution) as well as from the
rivers in British Honduras (at the southern edge
of its range), while moon and moon complete
are not known from the Rio Jamapa (at the
northern edge). The Rio Jamapa population
may have been derived from a chance invasion
of platyfish from the Rio Papaloapan, immedi-
ately to the south, with the moon and moon com-
plete patterns not represented in the introduc-
1967]
Kallman & Atz: Gene unci Chromosome Homology in Xiphophorus
129
Table XVI. Geography of the Known Melanophore Polymorphic Pigment Patterns
in Xiphophorus
No. of Macro-
No. of
melanophore
Tail Spot
Geographic
Species
patterns1 2 3 4 5 6
patterns1
Distribution
X. c. couchianus None None
X. c. gordoni
None
None
X. p. pygmaeus
None
None
X. p. nigrensis
None
12
X. milleri
2
33
X. clemenciae
None
None
X. m. montezumae
21
12
X. m. cortezi
2*
12
X. v. variatus
45
46
X. v. xiphidium
25
46
X. v. evelynae
15
None
X. maculatus
7
83,6
X. h. hellerii
None
None
X. h. strigatus
1
None
X. h. guentheri
2
1
X. It. alvarezi
None
None
Limited: spring pools of Huasteca Canyon,
Nuevo Leon
Limited: a few small lagunas near Cuatro
Cienegas, Coahuila
Limited: Rio Axtla (Rio Panuco system)
Limited: Nacimiento del Rio Choy (Rio
Panuco system)
Lake Catemaco
Limited: Rio Sarabia
Headwater streams of Rio Tamesi and northern
tributaries of Rio Panuco
Headwater streams (southern tributaries) of
Rio Panuco
Widespread: Rio Panuco, Rio Tamesi, Estero
Cucharas, Rio Tuxpan, Rio Cazones, Rio
Tecolutla, Rio Nautla
Rio Soto la Marina
Limited: headwaters of Rio Tecolutla
Widespread : Rio J amapa south to Belize River
Widespread: Rio Nautla and Rio Jamapa
Widespread: Rio Papaloapan and Rio Coat-
zacoalcos
Widespread: Rio Tonala (Mexico) south to
Rio Bonito (Honduras)
Limited: Rio Santo Domingo (Rio Usuma-
cinta system)
1 Not including the absence of any pattern, that is, the so-called wild type.
2 The tail spot pattern of X. p. nigrensis, X. m. montezumae, and X. m. cortezi appears to be identical.
3 Two patterns of X. milleri are identical, or nearly identical, with two of X. maculatus.
4 The macromelanophore patterns of X. m. cortezi are not identical with those of X. m. montezumae.
5 The macromelanophore patterns of each of the three subspecies of A', variatus are distinctive.
6 One pattern, simple crescent, appears to be identical in X. v. variatus, X. v. xiphidium, and X. maculatus.
Three other patterns are shared by X. v. variatus and X. v. xiphidium.
tion. This explanation could also account for
the absence of the N gene from the Jamapa. On
the other hand, it may be significant that of the
eight tail spot patterns of X. maculatus, two that
are most similar to each other, moon and moon
complete, are both absent from the Rio Jamapa.
Perhaps selection has been a factor in the elimi-
nation of these two similar patterns from the
Jamapa population. The absence of comet and
simple crescent from the Rio Usumacinta is
more difficult to understand. Neither chance
migration nor genetic drift appears to be a
likely explanation.
The pattern complete-crescent (Cc) of X.
maculatus might be considered to be composed
of two single patterns, simple crescent (C) and
axhead, both of which also occur by themselves.
The former is common in certain populations
(Gordon & Gordon, 1957), but the latter is
extremely rare (Gordon, 1947b). Another pat-
tern of X. maculatus that might be a composite
is moon complete (Me). Although crossing over
within the tail spot locus has never been ob-
served, the tail spot patterns may well comprise
a super-gene, as do many of the series of domi-
nant multiple alleles that produce polymorph-
ism (Ford, 1 964, 1 965 ) ,17 This view is supported
by the discovery of two X. maculatus in which
complete-crescent and dot were inherited as a
unit and one in which complete-crescent and
17 See footnote 3, page 110.
130
Zoologica: New York Zoological Society
[51:11
one-spot were so inherited. Composite tail spot
patterns are not known from any other species
of Xiphophorus.
The caudal pigment spot, the grave, of the
Rio Chajmaic swordtail does not resemble any
of the tail spots of other species. The fin rays
involved in this pattern are the same ones that
form the dorsal edge of the sword and become
pigmented, although to a much lesser degree, in
the males of previously described populations of
X. hellerii. When such males are examined, one
finds that the two or three fin rays immediately
above the dorsal edge of the sword are pig-
mented, and that the pigmentation of each one
ends progressively more anteriorly. This is an
arrangement almost identical to that of the grave
in female and immature swordtails of the Rio
Chajmaic.18 Although females of other sword-
tail populations do not exhibit the grave pattern,
they will develop a sword, edged typically with
black, when exposed to androgens (Dzwillo,
1962). The significant fact about the swordtail
population from the Chajmaic may not be that
both male and female fish have seemingly be-
come homozygous for a tail pattern allele, but
that they have evolved a genetic system that has
freed this pattern from the control of andro-
genic hormone. This change would not have
been a simple one and must have involved an
intensification of the pigmentation. Although
the same fin rays are involved, the dorsal edge
of the sword, especially the proximal portion,
is much darker and appears wider in the Rio
Chajmaic population than in the other sword-
tail populations.
Although the study of gene homologies among
members of the genus Xiphophorus provides
pertinent information on the evolution of these
fishes, it cannot serve as sole arbiter in deciding
their phylogenetic relationships. For example,
Rosen ( 1960) found X. maculatus and X. vari-
atus so closely related that he considered them
to constitute a well defined superspecies. The
homologous macromelanophore and tail spot
genes of these two species might therefore be
considered to corroborate their close evolution-
ary relationship, but a third species, X. milleri,
that also possesses the same two homologous
sets of alleles was placed in a different, less
closely related, species group by Rosen (1960)
on the basis of an array of morphological and
ecological characters.
Little work has been done on gene or chromo-
18 Some male X. pygmaeus nigrensis, in which sub-
species the dorsal margin of the caudal sword is not
edged with black, exhibit a pattern similar to grave.
some homologies in other genera of poeciliids.
In Poecilia, P. sphenops and P. latipinna possess
similar mottled and solid black pigmentation
and, in this respect, differ from all other mem-
bers of the genus. Schroder (1964) showed that
the solid black phenotype of P. sphenops results
from the additive effect of two loci (M and N)
that can combine freely. In P. latipinna, how-
ever, a single locus is concerned with black pig-
mentation. According to Schroder, the pigment
gene of latipinna is homologous to M of sphe-
nops, but this has not been definitely established
(see table 16, pg. 410 of Schroder, 1964). The
subgenus Lebistes is characterized by a high
degree of color polymorphism in adult males
( Rosen & Bailey, 1963). In addition to the well
known guppy, Poecilia reticulata, five species
are currently recognized, and the males of at
least the majority of them exhibit spots of many
shapes and colors on the body and dorsal and
caudal fins. In P. reticulata, most of these pat-
terns are controlled by sex-linked genes (Has-
kins et al., 1961 ) , but virtually nothing is known
about their inheritance in the other species. Pig-
mentary polymorphism has been described in
other poeciliids, sometimes in the form of black-
spotted individuals, e.g. in Gambusia, Phallo-
ceros, and Girardinus (Myers, 1925). Again,
nothing is known about the inheritance of these
patterns, although black-spotting and melanism
are usually confined to males in Gambusia affinis
(Myers, 1925; Regan, 1961). Because of the
light that may be shed on the evolution of sex-
determining mechanisms in the Family Poecili-
idae, possible sex linkage and chromosome
homology ought to be investigated wherever pos-
sible among these forms. Whatever the out-
come of such investigations, they will have im-
portant bearing on the understanding of sex
determination in fishes.
V. Summary
1. Fishes of the poeciliid genus Xiphophorus
can be hybridized with each other in the labora-
tory, and the hybrids are fertile to a significant
degree. Most of the species are polymorphic for
pigment patterns that are controlled by major
genes. These characteristics make Xiphophorus
especially suitable for the detection and study
of gene and chromosomal homologies.
2. Eighteen polymorphic pigment patterns
formed by macromelanophores and 16 formed
by micromelanophores are reviewed. Patterns
previously unrecognized are described in detail
and their mode of inheritance is analyzed. A
uniform system of nomenclature is applied to
the patterns, all previously used terms being
recorded and, if necessary, synonymized.
1967]
Kallman & Atz: Gene and Chromosome Homology in Xiphophorus
131
3. The sex chromosomes of X. maculatus, X.
variatus, and X. milleri are homologous, and
loci on them are occupied by homologous genes
that control the macromelanophore patterns.
4. It is highly probable that the multiple,
dominant alleles that control the series of simi-
lar micromelanophore tail patterns of X. macu-
latus, X. variatus, and X. milleri are homologus.
5. The homologies of the other pigment pat-
tern genes are not known, but some of them
have been shown to occur on non-homologous
chromosomes.
6. That the sex chromosomes of three species
of Xiphophorus are homologous strongly indi-
cates the existence of a common ancestor with
the same type of sex-determining mechanism
(XX-XY).
7. The macromelanophore patterns of all spe-
cies and subspecies are phenotypically distinct.
Hybridization either demonstrates or strongly
indicates that these differences are not the result
of modifying genes, but depend on the principal
genes themselves.
8. Three possible cases of crossing over within
the locus for tail spot patterns in X. maculatus
were discovered. The probability that these mul-
tiple alleles comprise a super-gene, or some
similar arrangement, is thus increased.
9. Both sexes of one population of X. hellerii
exhibit a micromelanophore tail pattern that
closely resembles a secondary sex character as-
sociated with the “sword” of the adult males in
other populations; possibly a change in the
genetic system has freed this pattern from the
control of male sex hormone.
10. In general, the species or subspecies of
Xiphophorus with extensive geographic ranges
are more polymorphic than those with restricted
ones.
1 1. A case of non-disjunction in a hybrid fish
(X. milleri x X. maculatus) is described.
Bibliography
Ahl, E.
1938. Beschreibung neuer Zahnkarpfen aus dem
zoologischen Museum. Zool. Anz., 124
(1): 53-58.
Anders, A. & F. Anders
1963. Genetisch bedingte XX- und XY- $$ und
YY- $$ beim wilden Platypoecilus macu-
latus aus Mexico. Z. Vererbungsl., 94(1):
1-18.
Anders, F. & K. Klinke
1965. Untersuchungen fiber die erbbedingte
Aminosafirenkonzentration, Farbgenma-
nifestation und Tumorbildung bei lebend-
gebarenden Zahnkarpfen (Poeciliidae). Z.
Vererbungsl., 96(1): 49-65.
Atz, J. W.
1959. Morphological and genetic studies on the
pigmentary patterns of xiphophorin fishes
and their hybrids. PhD Thesis. Dept. Biol-
ogy, New York Univ.
1962. Effects of hybridization on pigmentation
in fishes of the genus Xiphophorus. Zoo-
logica, 47(4): 153-181.
de Beer, G. R.
1958. “Embryos and Ancestors.” Third ed. Ox-
ford. xii +197 pp.
Bellamy, A. W.
1922. Sex-linked inheritance in the teleost,
Platypoecilus maculatus Gfinth. Anat.
Rec., 24(6): 419-420. Abstract.
Bellamy, A. W. & M. L. Queal
1951. Heterosomal inheritance and sex deter-
mination in Platypoecilus maculatus. Gen-
etics, 36(1): 93-107.
Breider, H.
1936. Eine Allelenserie von Genen verschiedener
Arten. Z. Ind. Abst. u. Vererbgsl., 72(1):
80-87.
1938. “Die Gesetze der Vererbung und Zfich-
tung in Versuchen mit Aquarienfischen.”
Gustav Wenzel & Sohn, Braunschweig.
188 pp.
1949. Die Bedeutung der Aquarienkunde ffir die
Wissenschaft. Wschr. Aquar. Terr’kd., 43
(2 Sonderheft): 371-386.
Breider, H. & A. Mombour
1949. Das Farbgen “Nigra-caudal” (Nc) des
Xiphophorus montezumae. Wschr. Aquar.
Terr, kd„ 43(11): 309-313.
Brown, R.
1954. “Composition of Scientific Words.” Pri-
vately published, Baltimore 882 pp.
Dobzhansky, T.
1959. Evolution of genes and genes in evolution.
Cold Spring Harbor Symp. Quant. Biol.,
24: 15-30.
Dzwillo, M.
1962. Einfluss von Methyltestosteron auf die
Aktivierung sekundarer Geschlechtsmerk-
male fiber den arttypischen Ausbildungs-
grad hinaus (Untersuchungen an xipho-
phorinen Zahnkarpfen). Verh. Dt. Zool.
Gesellsch., Wien 1962: 152-159.
Ford, E. B.
1964. “Ecological Genetics.” Wiley, New York,
xv + 335 pp.
1965. “Genetic Polymorphism.” M. I. T. Press,
Cambridge, Massachusetts. 101 pp.
132
Zoologica: New York Zoological Society
[51:11
Fraser, A. C. & M. Gordon
1929. The genetics of Platypoecilus. II. The link-
age of two sex-linked characters. Genetics,
14(2): 160-179.
Gordon, H. & M. Gordon
1950. Colour patterns and gene frequencies in
natural populations of a platyfish. Hered-
ity, 4(1): 61-73.
1957. Maintenance of polymorphism by poten-
tially injurious genes in eight natural popu-
lations of the platyfish, Xiphophorus mac-
ulatus. J. Genet., 55(1): 1-44.
Gordon, M.
1927. The genetics of a viviparous top-minnow
Platypoecilus; the inheritance of two kinds
of melanophores. Genetics, 12(3): 253-
283.
1931. Morphology of the heritable color pat-
terns in the Mexican killifish Platypoecilus.
Amer. J. Cancer, 15(2): 732-787.
1937a. Genetics of Platypoecilus. III. Inheritance
of sex and crossing over of the sex chro-
mosomes in the platyfish. Genetics, 22(3):
376-392.
1937b. Heritable color variations in the Mexican
swordtail-fish. J. Hered., 28(6): 220-230.
1938. The genetics of Xiphophorus hellerii:
heredity in montezuma, a Mexican sword-
tail fish. Copeia, 1938, (1): 19-29.
1943. Genetic studies of speciation in the sword-
tail-platyfish group and of the experimen-
tally produced hybrids. Trans. N. Y. Acad.
Sci., Ser. II, 5(4): 63-71.
1946a. Interchanging genetic mechanisms for sex
determination in fishes under domestica-
tion. J. Hered., 37(10): 307-320.
1946b. Introgressive hybridization in domesticated
fishes. The behavior of comet, a Platy-
poecilus maculatus gene, in Xiphophorus
hellerii. Zoologica, 31(2): 77-88.
1947a. Genetics of Platypoecilus maculatus. IV.
The sex determining mechanism in two
wild populations of the Mexican playfish.
Genetics, 32(8): 8-17.
1947b. Speciation in fishes. Distribution in time
and space of seven dominant multiple al-
leles in Platypoecilus maculatus. Advances
Gen., 1: 95-132.
1948. Effects of five primary genes on the site
of melanoma in fishes and the influence of
two color genes on their pigmentation.
Pg. 216-268 of “The Biology of Melano-
mas,” Spec. Pub. N. Y. Acad. Sci., 4.
1950a. Fishes as laboratory animals. Pg. 345-449
of “The Care and Breeding of Laboratory
Animals.” E. Farris, Editor, John Wiley &
Sons, New York.
1950b. Heredity of pigmented tumours in fish.
Endeavour, 9(33): 26-34.
1951a. The variable expressivity of a pigment cell
gene from zero effect to melanotic tumor
induction. Cancer Res., 11(9): 676-686.
195 lb. Genetics of Platypoecilus maculatus. V.
Heterogametic sex-determining mecha-
nism in females of a domesticated stock
originally from British Honduras. Zoo-
logica, 36(2) : 127-134.
195 lc. Genetic and correlated studies of normal
and atypical pigment cell growth. Growth,
Symposium, 10: 153-219.
1952. Sex determination in Xiphophorus (Platy-
poecilus) maculatus. III. Differentiation of
gonads in platyfish from broods having a
sex ratio of three females to one male.
Zoologica, 37(2): 91-100.
1956a. The red jet swordtail. Tropical Fish Hob-
byist [Jersey City], 5(1): 6, 8, 38-39, 42-
43, 46-47. [Extract from: “Swordtails. The
Care and Breeding of Swordtails.” By
Myron Gordon. 24 pp. T.F.H. Publica-
tions, Inc., Jersey City, N. J.]
1956b. An intricate genetic system that controls
nine pigment cell patterns in the platyfish.
Zoologica, 41 (4) : 153-162.
1958. Genetic and developmental differences be-
tween two morphologically similar pig-
ment cells with reference to melanoma.
Anat. Rec., 132 (3): 446. Abstract.
Gordon, M. & K. F. Baker
1955. Post-natal lethal gene in the platy-
fish Xiphophorus maculatus when homo-
zygous. Anat. Rec., 122(3): 436-437. Ab-
stract.
Gordon, M. & A. C. Fraser
1931. Pattern genes in the platyfish. J. Hered.,
22(6): 168-185.
Gordon, M. & G. M. Smith
1938. The production of a melanotic neoplastic
disease in fishes by selective matings. IV.
Genetics of geographical species hybrids.
Amer. J. Cancer, 34(4): 543-565.
Haskins, C. P., E. F. Haskins,
J. J. A. McLaughlin & R. E. Hewitt
1961. Polymorphism and population structure in
Lebistes reticulatus, an ecological study.
Pg. 320-395 of “Vertebrate Speciation.”
University of Texas Press.
Kallman, K. D.
1963. Hunting for a chromosome in the jungles
of Guatemala. Animal Kingdom, 66(4):
104-109.
1965a. Genetics and geography of sex determina-
tion in the poeciliid fish, Xiphophorus
maculatus. Zoologica, 50(3): 151-190.
1965b. Sex determination in the teleost Xipho-
phorus milleri. Amer. Zool., 5: 246-247.
Abstract.
1967)
Kallman & Atz: Gene and Chromosome Homology in Xiphophorus
133
Kallman, K. D. & M. Gordon
1958. Genetics of fin transplantation in xipho-
phorin fishes. Ann. N.Y. Acad. Sci., 73
(3): 599-610.
Kerrigan, A. M.
1934. The inheritance of the crescent and twin
spot marking in Xiphophorus helleri.
Genetics, 19(6): 581-599.
Kosswig, C.
1933. Genotypische und phanotypische Ge-
schlechtsbestimmung bei Zahnkarpfen. III.
Farbfaktoren als relative Geschlechtsrea-
lisatoren. Roux’ Archiv Entwicklungs. Or-
gan., 128(2): 393-446.
1934. Farbfaktoren und Geschlechtsbestim-
mung. Der Zfichter, 6(2) : 40-47.
1935a. Genotypische und phanotypische Ge-
schlechtsbestimmung bei Zahnkarpfen. V.
Ein X (Z)-Chromosom als Y-Chromsom
in fremdem Erbgut. Roux’ Archiv. Ent-
wicklungs. Organ., 133(1/2): 118-139.
1935b. Die Kreuzung zweier XX-bzw. XY- Ge-
schlechter miteinander und der Ersatz
eines Y-Chromosoms einer Art durch das
A'-Chromosoms einer anderen. Der Zuch-
ter, 7(2): 40-48.
1936. Kleinere Mitteilungen fiber Art- und Gat-
tungbastarde von Zahnkarpfen. Zool. Anz.,
114(7/8): 195-206.
1937. fiber die veranderte Wirkung von Farb-
genen in fremden Genotypen. Biologia
Generalis, 13(1): 276-293.
1938. fiber einen neuenFarbcharakter des Platy-
poecilus maculatus. Rev. Fac. Sci. Istanbul,
new ser., 3(4) : 1-8.
1939. Die Geschlechtsbestimmung in Kreuzun-
gen zwischen Xiphophorus und Platypoe-
cilus. Rev. Fac. Sci. Istanbul, new ser.,
4(1/2): 1-54.
1948. Homologe und analoge Gene, parallele
Evolution und Konvergenz. Comm. Fac.
Sci. Univ. Ankara, 1: 126-177.
1959. Beitrage zur genetischen Analyse xipho-
phoriner Zahnkarpfen. Biol. Zentralblatt,
78(5): 711-718.
1961. fiber sogenannte homologe Gene. Zool.
Anz., 166(9/12): 333-356.
Kosswig, C. & M. Oktay
1955. Die Geschlechtsbestimmung bei den Xi-
phophorini (Neue Tatsachen und neue
Deutungen). Istanbul Univ. Fen Fak. Hid-
rob., ser. B., 2(4): 133-156.
Kosswig, C. & A. Sengun
1945. fiber arttrennende Mechanismen. Rev.
Fac. Sci. Istanbul, ser. B., 10(3): 164-214.
MacIntyre, P. A.
1961a. Deleterious effects of a gene causing ex-
cessive pigmentation in the platyfish. J.
Hered., 52(6): 292-294.
1961b. Spontaneous sex reversals of genotypic
males in the platyfish (Xiphophorus macu-
latus). Genetics, 46(5): 575-580.
1961c. Crossing over within the macromelano-
phore gene in the platyfish, Xiphophorus
maculatus. Amer. Nat., 95 (884): 323-
324.
Marcus, T. R. & M. Gordon
1954. Transplantation of the Sc melanoma in
fishes. Zoologica, 39(3): 123-131.
Mayr, E.
1963. “Animal Species and Evolution.” Harvard
Univ. Press, Cambridge, Massachusetts.
xiv+797 pp.
Myers, G. S.
1925. Concerning melanodimorphism in killi-
fishes. Copeia, (137): 105-107.
Oktay, M.
1954. fiber Besonderheiten der Vererbung des
Gens fuligonosus bei Platypoecilus macu-
latus. Rev. Fac. Sci. Istanbul, ser. B,
19(4): 303-327.
1959a. fiber Ausnahmemaennchen bei Platypoe-
cilus maculatus und eine neue Sippe mit
XX-Maennchen und XX-Weibchen. Rev.
Fac. Sci. Istanbul, ser. B, 24(1/2): 75-91.
1959b. Weitere Untersuchungen fiber eine Aus-
nahme (XX-) Sippe des Platypoecilus
maculatus mit polygener Geschlechtsbe-
stimmung. Rev. Fac. Sci. Istanbul, ser. B,
24(3/4): 225-233.
1962. Die Rolle artfremder Gonosomen bei der
Geschlechtsbestimmung von Bastarden
mit Platypoecilus xiphidium. Istanbul
Univ. Fen. Fak. Hidrob., ser. B, 4(1/2):
1-13.
1964. fiber genbedingte rote Farbmuster bei Xi-
phophorus maculatus. Mitt. Hamburg.
Zool. Mus. Inst., Kosswig-Festschrift: 133-
157.
Patterson, J. T. & W. S. Stone
1952. “Evolution in the genus Drosophila.” Mac-
millan, New York. 610 pp.
Peters, G.
1964. Vergleichende Untersuchungen an drei
Subspecies von Xiphophorus helleri He-
ckel (Pisces). Z. zool, Syst. Evolut.-forsch.,
2: 185-271.
Regan, I. D.
1961. Melanism in the poeciliid fish, Gambusia
afjinis (Baird and Girard). Amer. Mid-
land Naturalist, 65( 1) : 139-143.
Rosen, D. E.
1960. Middle-American poeciliid fishes of the
genus Xiphophorus. Bull. Florida State
Mus., Biol. Sci., 5(4) : 57-242.
134
Zoologica: New York Zoological Society
[51:11
Rosen, D. E. & R. M. Bailey
1963. The poeciliid fishes (Cyprinodontiformes),
their structure, zoogeography, and sys-
tematics. Bull. Amer. Mus. Nat. Hist.,
126: 1-176.
Rust, W.
1939. Mannliche und weibliche Heterogametie
bei Platypoecilus variatus. Z. indukt. Ab-
stamm.-u. Vererb.-Lehre, 77: 172-176.
1941. Genetische Untersuchungen fiber die Ge-
schlechtsbestimmungstypen bei Zahnkarp-
fen unter besonderer Berficksichtigung
von Artkreuzungen mit Platypoecilus vari-
atus. Z. indukt. Abstamm.-u. Vererb.-
Lehre, 79(3): 336-395.
Schroder, J. H.
1964. Genetische Untersuchungen an domesti-
zierten Stammen der Gattung Mollienesia
( Poeciliidae ) . Zoologische Beitrage,
10(3): 369-463.
Serra, J. A.
1965. “Modern Genetics.” Vol. 1. Academic
Press, New York, xii+540 pp.
Spencer, W. P.
1949. Gene homologies and the mutants of Dro-
sophila hydei. Pp. 23-44 of “Genetics,
Paleontology, and Evolution.” Princeton
Univ. Press, Princeton, New Jersey.
Sterba, G.
1963. “Freshwater Fishes of the World.” Viking
Press, New York. 878 pp.
Zander, C. D.
1962. Untersuchungen fiber einen arttrennenden
Mechanismus bei lebendgebarenden Zahn-
karpfen aus der Tribus Xiphophorini.
Mitt. Hamburg. Zool. Mus. Inst., 60: 205-
264.
1965. Die Geschlechtsbestimmung bei Xipho-
phorus montezumae cortezi Rosen (Pisces).
Z. Vererbungsl., 96(2) : 128-141.
1967]
Kallman & Atz: Gene and Chromosome Homology in Xiphophorus
135
Fig.
Fig.
Fig. 3
Fig.
Fig.
Fig. 6
Fig. 7
Fig. 8
EXPLANATION OF THE PLATES
Plate I
Xiphophorus variatus variatus. Female
(ped. 1671), an eleven and a half month
old fish in which the spots of the rnacro-
melanophore pattern, punctatus (P2), have
coalesced to form an irregular black band,
The micromelanophore pattern, crescent
(C) is also shown.
Backcross hybrids, (maculatus x couch-
ianus) x couchianus . Female, above (ped.
1166) has one-spot (O). Male, below (ped.
881), has dot (D). These tail spot patterns
have maintained their distinctiveness. See
Table VIII.
Xiphophorus pygmaeus nigrensis. Male,
above (ped. 1813), and female, below
(ped. 1815), have the tail spot pattern,
caudal blotch (Cb). Male, center (ped.
1813), is wild type, that is, has no tail
spot pattern.
Plate II
Xiphophorus milleri. Male, lower left
(ped. 1748), has macromelanophore pat-
tern, spotted ventral (Sv,) and micromel-
anophore tail spot patterns, point (Pt)
and bar (B). Female, upper left (ped.
1748), has point. Female, upper right
(ped. 1628), has tail spot pattern, single
spot (Ss). Female, lower right (ped. 1602),
has bar.
Xiphophorus milleri. Male, above (ped.
1602), has bar (B). Female, left, below
(ped. 1628), has single spot (Ss), which
appears bar-like because of a high light.
Female, right, below (ped. 1601), has
point (Pt). The gonopodium of the male
is pigmented with micromelanophores.
Plate III
Xiphophorus maculatus. Male, left (Cp-
11), shows two tail spot patterns, com-
plete-crescent (Cc) and dot (D). Female,
right (Jp-3010), shows the one-spot (O)
for which it is homozygous.
Xiphophorus maculatus. This female (ped.
270) is one of the offspring of the fish in
Fig. 6. It shows the complete-crescent (Cc)
and one-spot (O) patterns. See Table VIII.
For a discussion of the effect of intra-
specific hybridization on the macromel-
anophore pattern, spotted dorsal (Sd), see
Gordon ( 195 la).
Xiphophorus maculatus, Hp-1 strain. Both
fish have the tail spot pattern, complete-
crescent (Cc), and lack the dot (D). The
female, above, shows a typical manifesta-
tion of the macromelanophore pattern,
spotted dorsal. The male, below, has a
prominent slash mark, a micromelano-
phore pattern whose mode of inheritance
is not known.
Plate IV
Fig. 9. Xiphophorus hellerii guentheri, Bx strain.
Both male and female have the macro-
melanophore pattern, dabbed (Db1).
Fig. 10. Xiphophorus hellerii guentheri, Hx strain.
The male has the macromelanophore pat-
tern, dabbed (Db2), in which the spots are
typically arranged in rows.
Plate V
Fig. 11. Xiphophorus hellerii, Ch strain. The tail
spot pattern (grave) of the female (be-
low) and the heavy pigmentation of the
dorsal edge of the caudal sword of the
male are characteristic of this form.
Fig. 12. Xiphophorus variatus xiphidium. Male,
left (ped. 1711), has macromelanophore
pattern, flecked (FI1), while female, right
(ped. 1708 or 1758), has dusky (FI2).
Both fish have the tail spot pattern, ped-
uncular spot (Ps), and in the male, its ex-
tension behind the hyplural bone is clearly
evident.
Fig. 13. Xiphophorus montezumae montezumae
(ped. 1817) with micromelanophore pat-
tern, caudal blotch (Cb). Cross section
through the proximal portion of the cau-
dal fin showing dense accumulations of
pigment cells in the dermis between the
musculature and scales, between the
scales, and along the connective tissue that
lies between the dorsal and ventral edges
of the lepidotrichia and the dermis. X 65.
Plate VI
Fig. 14. Xiphophorus variatus xiphidium (ped.
1792) with micromelanophore pattern,
peduncular spot (Ps). Cross section
through the last caudal vertebra. In con-
trast to the one-spot pattern (O) of X.
maculatus, the pigment cells are located
in the deep-lying muscles, especially
around blood vessels and nerves. X 65.
Fig. 15. Xiphophorus variatus xiphidium (ped.
1792) with micromelanophore pattern,
peduncular spot (Ps). Cross section at the
level of the hyplural plate. Pigment cells
are located between the deep-lying mus-
cles and around the blood vessels. X 130.
Fig. 16. Xiphophorus maculatus (Np strain) with
micromelanophore pattern, moon (M).
Cross section through the last vertebra.
Pigment cells are located in the dermis
and the superficial muscles immediately
underneath. X 65.
Fig. 17. Xiphophorus maculatus (Np strain) with
micromelanophore pattern, moon (M).
Cross section at the level of the hyplural
plate. Pigment cells are located in the
dermis and between the superficial mus-
cles. X 130.
KALLMAN & ATZ
PLATE I
FIG. 3
GENE AND CHROMOSOME HOMOLOGY IN FISHES OF THE GENUS ( XIPHOPHORUS )
KALLMAN & ATZ
PLATE II
FIG 4
FIG. 5
GENE AND CHROMOSOME HOMOLOGY IN FISHES OF THE GENUS ( XIPHOPHORUS )
KALLMAN & ATZ
PLATE III
FIG. 6
FIG. 7
FIG. 8
GENE AND CHROMOSOME HOMOLOGY IN FISHES OF THE GENUS ( XI PHOPHORUS )
KALLMAN & ATZ
PLATE IV
FIG. 9
FIG. 10
■ "t fc* «, f
GENE AND CHROMOSOME HOMOLOGY IN FISHES OF THE GENUS ( XI PHOPHORUS )
KALLMAN & ATZ
PLATE V
FIG 11
*
FIG. 12
FIG. 13
GENE AND CHROMOSOME HOMOLOGY IN FISHES OF THE GENUS ( XIPHOPHORUS )
KALLMAN & ATZ
PLATE VI
FIG. 14
FIG. 15
FIG. 17
FIG. 16
GENE AND CHROMOSOME HOMOLOGY IN FISHES OF THE GENUS ( XIPHOPHORUS )
12
On the Marking Behavior of the Kinkajou ( Potos fiavus Schreber)
Ivo Poglayen-Neuwall1
(Plates I-III)
Introduction
UNTIL recently, the function and purpose
of the conspicuous glandular organs of
the kinkajou were the subject of con-
jecture (Pocock, 1921; Fiedler, 1957) and not
corroborated by actual observations. The writer
has kept a number of kinkajous since 1956 and
has been able to make several observations on
their marking behavior (Poglayen-Neuwall 1962)
which, with further observations, bring this com-
plex problem closer to a solution.
Three of eight males and one of four females
studied demonstrated repeatedly typical marking
behavior. It is noteworthy that all animals which
marked were born and raised in captivity (Albu-
querque Zoo), and that none of these animals
was observed marking while in the large outdoor
cage; this was true of those living there perma-
nently (during the warm season) as well as those
introduced and reintroduced at different times.
The animals, singly or in pairs, spent frequent
brief periods (15 minutes to about three hours)
romping at large in the writer’s home during
which times they were under constant observa-
tion. It was only then that any animal was seen
to display marking behavior.
In October 1965, a pair of kinkajous was
donated to us by the Memphis (Tennessee) Zoo.
The animals, born in that zoo nine and three
years earlier, were received at the Louisville Zoo
and maintained in a 6 x 6 x 6 foot indoor cage,
where they soon exhibited a pattern of scent-
marking.
Observations
All three known skin glands, the paired man-
dibular gland, the throat gland and the abdomi-
^irector, Louisville Zoological Garden, City Hall,
Louisville, Kentucky.
nal gland, are used for marking. The first two
glands, at least, also constitute, as described
elsewhere (Poglayen-Neuwall op. cit.), organs
for sexual stimulation.
The animals displayed normal behavior, in-
cluding marking, only during their activity phase
in the evening and at night. Marking was not
correlated with a specific time of year, and breed-
ing, in captivity and probably in the wild, is not
seasonal (Poglayen-Neuwall op. cit). Asdell
( 1964), however, suggests a main whelping sea-
son from May to September, with one litter re-
corded for April and one for December.
In the writer’s home the following kinds of
marking2 took place:
a) Mandibular glands (one or both glands,
alternately) were used to mark the rounded legs
of a table, a door knob, the lower part of a tele-
phone receiver, and the writer’s shoe. Marking
was accomplished by rubbing the glandular plate
once or repeatedly in a caudad direction upon
the object. The Memphis female very frequently
marked the vertical corner pipes of her cage
(preferably the ones pointing towards the service
area) by pressing or, less often, wiping briefly
with one of the mandibular glands. Within a few
weeks a dark brown layer of secretion, sebum
and dirt had accumulated on the lower part of
these preferred “marking posts.” The male was
rarely observed marking. When doing so he used
the female’s posts.
b) The throat gland was employed to mark
a certain pillow (or a substitute pillow as long
as it was in the location of the original one),
the telephone, the upper rim of a wooden box,
the upper edge of the back of the couch, and the
occipital region of my wife. This marking was
2Most of the objects marked were characterized by
rounded contours.
137
138
Zoologica: New York Zoological Society
[51:12
either a simple, slight wiping action or a repeated
sweeping of the gular region in one direction
with noticeable pressure, from somewhat for-
ward of the sternum toward the animal’s throat.
After being placed in the cage of two females
known to him only by sight, the Memphis male
demonstrated very intensive marking behavior
by frequently pressing his throat gland with the
head held straight up against the vertical corner
pipes, and also by pressing or, less often, wiping
with the gland on the largest climbing limb. This
behavior was noticed beginning on the second
day after his transfer, and it lasted until the time
of his removal because of incompatibility five
days later. Moved into an unfamiliar cage and
kept by himself, he immediately ceased to ex-
hibit this marking pattern.
c) A kinkajou, standing on its hind legs upon
the seat of a couch, rubbed the abdominal gland-
ular area against the thigh of my wife as she
stood next to the couch. The animal, assuming
a prone position, also marked the upper edge
of the back of the couch. Marking took the form
of an antero-posterior thrusting of the abdomen
on the supporting base.
An unusual observation was made on the
Memphis female, who was kept at the time with
her five-week-old female cub. Since the arrival
of the adult pair from Memphis nine months
earlier, two adult female kinkajous had been
kept in a cage three feet from the cage housing
the pair. At the birth of the baby the Memphis
male was removed and housed separately in an
adjacent room. On four successive nights the
Memphis female was seen marking fresh food
objects. Twice it was a whole, peeled banana and
twice an unpeeled quarter of an orange. The
marking followed a general routine. After the
animal finished part of her food ration, she took
one banana (or orange section) from the feeding
pan, placed it on the cage floor, and stepped with
both hind feet on the fruit. She remained in this
position for from two to three seconds; she then
stepped backward and, bending the forelegs,
dragged her abdomen over the fruit in backward
direction from the perineum to the sternum.
Thereafter the abdomen was raised and brought
forward again without touching the fruit. The
same movements were repeated two more times.
Once this marking procedure was somewhat al-
tered; in addition to the backward dragging or
rubbing, the animal also marked while moving
forward. The animal stepped on the fruit after
each of the three backward-forward movements.
The sequence of frequency in marking in-
volved first the mandibular glands, then the
throat gland, and last the abdominal gland. The
youngest kinkajou observed to manifest marking
behavior (with mandibular glands) was a young
male, 92 days old; this is long before sexual ma-
turity, which is assumed to be attained at about
16-18 months.
Discussion
The following possible interpretations of the
significance of the glandular organs in the biol-
ogy of the kinkajou suggest themselves:
1 ) Demarcation of the boundaries of the home
range (or a territory) for the individual,
the pair, the family, or the band. The gland-
ular secretion has a deterrent effect on the
competitor for food or the sexual rival.
2 ) Scent used in defense against predators.
3) Marking of trails.
4) Scent as a means in intraspecific relation-
ships (rank order, identification).
5) Secretion with sexual significance.
a. Facilitation in meeting of the sexes.
b. Marking of the sexual partner during
the mating period.
c. Glandular secretion as a sexual stimu-
lant.
Field observations (Anthony 1916, Enders
1935, Gaumer 1917, Goldman 1920, Poglayen-
Neuwall 1962, and Flandley, personal communi-
cation, 1964) make it seem unlikely that kinka-
jous possess a “territory” (as defined by Burt,
1943) which the individual or the social group
defends against intruders of the same species
or the same sex. Kinkajous do not form well-
organized social groups. Whether or not they
are at times gregarious, forming perhaps loosely
organized bands composed of several individuals
of both sexes, a family group, a pair, or a
female with young, still is not known with cer-
tainty. Naturalists report having seen kinkajous
in pairs, in bands, and less often as solitary
individuals. It is certain that a number of animals
may form feeding groups on fruit-bearing trees.
The fact that strange males, as a rule, may be
put together and kept in one enclosure ( including
one with females) may be indicative of the ani-
mals’ sociability. Only a few cases of incompati-
bility among adult males are known to me. Fight-
ing between an old male in an established captive
group and a newly introduced male resulted in
serious injury inflicted to the latter (Trebbau,
personal communication, 1962). Males born in
a group of kinkajous at the West Berlin Zoo had
to be removed when two years old because of
damaging fights among each other and/or the
old breeding male (Klos in litt. 1966). It should
be mentioned that the quarters at West Berlin
Zoo were quite small for the number of animals
therein confined.
1967]
Poglayen-Neuwall: Marking Behavior of the Kinkajou
139
A theory which must be considered is a pos-
sible random marking within the home range;
this may not be done alone for the demarcation
of a home range, but perhaps more so for per-
sonal identification, thereby helping to keep the
individuals of the band in contact. Marking is
not a part of the nuptial display as the urine-
rubbing described for male coatis, Nasua narica,
in the breeding season (Kaufmann 1962), nor’
does the marking of the kinkajou belong to the
pattern of threat and fighting behavior as in
many rodents, e.g. the non-territorial guinea pig
(Kunkel & Kunkel 1964).
Occasionally kinkajous of the same or oppo-
site sex, when being introduced, will sniff at each
other’s throat glands or mandibular glands. Ap-
parently this behavioral trait helps in recogniz-
ing and identifying an individual. After a three-
week separation the female from Memphis was
reintroduced to her mate. Very intensive mutual
olfactory inspection was at once noticeable, with
the female chirping almost constantly. The male
inspected the following areas of the female in
decreasing order of intensity and frequency:
nape, throat gland, mandibular glands, abdomi-
nal gland, and perineal region. The female
checked the male’s mandibular glands, penis,
abdominal gland, and throat gland. At a later
time when the male was returned to the cage
containing the female, essentially the same ol-
factory display took place, but with the chirping
female being the slightly more active individual.
As is well known, kinkajous emanate a clearly
perceivable musk-like odor which cannot be
traced to a particular glandular area. It is not
known if this odor and/or the glandular texture
make the kinkajou distasteful to a predator, but
I am inclined to think that this is not so. Kinka-
jous do not possess any musk glands which emit
secretions explosively like some of the mustelids,
or strongly odorous, anal musk like Bassariscus
astutus (Edwards 1955, Kaufmann 1965, in litt.).
In fact Potos is reported not to have anal glands
(Pocock op. cit) .
Since both sexes possess the above-mentioned
skin glands and since we know that sleeping
sites or nests can be located at considerable dis-
tances from feeding sites, there may be the pos-
sibility of scent-marking trails. Eibl-Eibesfeldt
(1953) assumes that the greater galago (Galago
crassicaudatus) scent-marks trails in the tree
tops, but in that instance marking is done with
the palms of hands and feet which are actively
impregnated with urine. Ilse (1955) describes
similar observations with Loris tardigradus.
Fiedler ( 1957) elaborates in great detail on the
scent-marking with secretion of the anal glands
in both sexes of the lesser panda (Ailurus
fulgens) on objects along definite trails in
trees and on the ground. Marking on the
ground with anal gland secretion by male
coatis (Nasua), a gregarious species, is re-
ported by Fiedler (op. cit.) but denied by Kauf-
mann (1962 and pers. com. 1963). In this con-
text two other species of procyonids should be
mentioned also. The cacomistle (Bassariscus
astutus) is said to derive its characteristic sweet-
ish-musk body odor through secretion from the
anal glands. According to Richardson (1942),
“the fluid appeared when the animal was fright-
ened. . . . The species, as far as I have seen, makes
no effort to throw or wipe the fluid on objects
with which it comes in contact.” In contrast
Fiedler (op. cit.) described marking by the male
over protruding points of branches, supposedly
by means of a discharge from the anal glands.
Kaufmann (1965, in litt.) relates observations
of a captive mature male “standing on the floor
on his hind legs and resting his forepaws on the
vertical branch, then rubbing up and down much
like a coati rubbing urine. The branch is visibly
wet afterwards. I have never seen him rub his
anal region on anything.” From the little that is
known of the natural history of this species it
appears that cacomistles live alone or in pairs,
and thus the frequent marking activity through-
out the year serves in this case to determine the
boundaries of the territory of the individual or
pair. Poglayen-Neuwall & Poglayen-Neuwall
(1965) give an account of the marking with
urine by both sexes of the olingo (Bassaricyon),
whose anal glands are modified to serve as a
means of defense, releasing a foul-smelling liq-
uid. Bassaricyon, which is apparently not a so-
ciable species may use urine-rubbing for mark-
ing trails leading through the tree tops, possibly
for territorial marking in both sexes outside the
breeding seasons.
The marking of one or several trails, as well
as particular objects within the home range,
could further the meeting of the sexes, especially
if we assume that kinkajous are more or less
solitary, at least during part of the year. The
marking activity is independent of the sexual
cycle, in contrast to the European pine marten,
Martes mattes (Landowski 1961).
Some mammals such as the Waller’s gazelle,
Litocranius walleri (Walther 1958), show a
rather aberrant behavior pattern; in this species
the male actively marks the female with scent
from his antorbital glands during the mating
season. Recently, very interesting observations
on Petaurus were reported (Schultze-Westrum
1964). The flying phalanger possesses a frontal
and a sternal glandular organ. These glands, as
well as the urine, convey, according to Schultze-
Westrum (op. cit.) three individually differenti-
ated scents. The secretions are used primarily for
140
Zoologica: New York Zoological Society
[51:12
self-odoration and for the marking of individuals
of their own clan; thus a clan-specific odor spec-
trum is established within which the odor of
strong males is dominant, whereby, without any
fighting, a rank order can be established and
maintained. Marking is used only secondarily by
males for the determination of a territory. It is
not known if the glands of Potos produce indi-
vidually distinguishable secretions for each
gland, but prolonged observations make marking
of one animal by another appear highly improb-
able.
It seems almost certain that one function of
the glandular secretion can be that of sexual
stimulus at the beginning of the copulatory act.
Repeated observations, photographically re-
corded, tend to support this theory (Poglayen-
Neuwall 1962). The licking of secretion of the
sexual partner as an appetitive behavior for the
mating activity which frequently follows does
not seem to be compulsory, however. Another
breeding pair of kinkajous was observed several
times copulating and on two of these occasions
the male showed nothing of this peculiar behav-
ior so characteristic of the Albuquerque male.
Conclusions
Concurring with the assumption of Enders
(1935 ) , Gaumer ( 1917) , and others that kinka-
jous in their habitat form loose bands, and know-
ing that both sexes display behavioral patterns
of scent-marking which are not correlated with
a particular seasonal breeding period (the species
is polyestrous) , the following assumptions can
be made:
a. Marking activity occurs within the home
range to facilitate contact within the social
group, and/or
b. Marking of trails occurs from the sleeping
den to the feeding sites.
No definite answer to the exact purpose(s) of
this species’ marking display with its three differ-
entiated dermal glands can be given so long as
we lack the technical equipment which would
enable us to observe this strictly nocturnal and
arboreal species more closely and continually
over a longer period of time in its native habitat.
Acknowledgments
I am grateful to my wife for the assistance she
has lent me in the course of this study. Thanks
also to Dr. Charles O. Handley, Jr., U. S. Na-
tional Museum, who kindly narrated to the
writer personal field observations. I am indebted
to Drs. John H. Kaufmann, University of Flor-
ida, H. G. Klos, Director Zoologischer Garten,
West Berlin, and P. Trebbau, Director, Jardin
Zoologico de Caracas, for information gener-
ously given. I should like to thank Mr. Joseph A.
Davis, Jr., Curator of Mammals, New York
Zoological Park, for critically reading the manu-
script and making helpful suggestions.
References
Anthony, H. E.
1916. Panama Mammals Collected in 1914-15;
Bull. Amer. Mus. Nat. Hist. 35: 357-376.
Asdell, S. A.
1964. Patterns of Mammalian Reproduction.
2nd. Ed. Cornell Univ. Press; Ithaca, N.Y.
670 pp.
Burt, W. H.
1943. Territoriality and Home Range Concepts
as Applied to Mammals. J. Mamm. 24
(3): 346-352.
Edwards, R. L.
1955. Observations on the Ring-tailed Cat. J.
Mamm. 36 (2): 292-293.
Eibl-Eibesfeldt, I.
1953. Eine besondere Form des Duftmarkierens
beim Riesengalago, Galago crassicaudatus
E. Geoffroy 1812. Saugetierkundl. Mitt. 1:
171-173.
Enders, R. K.
1935. Mammalian Life Histories from Barro
Colorado Island, Panama; Bull. Mus.
Comp. Zool. Harvard 78: 385-502.
Fiedler, W.
1957. Beobachtungen zum Markierungsverhalten
einiger Saugetiere; Z. Saugetierkunde; 22:
57-76.
Gaumer, G. F.
1917. Monografia de los Mamiferos de Yucatan,
Mexico, D. F. Departamento de Talleres
Graficos, Secretaria de Fomento; 331 pp.
Goldman, E. A.
1920. Mammals of Panama. Smith. Misc. Coll.
69 (5) 309 pp.
Ilse, D.
1955. Olfactory marking of territory in two
young male loris, Loris tardigradus lydek-
kerianus, kept in captivity in Poona. J. An-
imal Behav. (3): 118-120.
Kaufmann, J. H.
1962. Ecology and Social Behavior of the Coati,
Nasua narica, on Barro Colorado Island,
Panama. Univ. Calif. Pubis. Zool 60 (3):
95-222.
Kunkel, P. & 1. Kunkel
1964. Beitrage zur Ethologie des Hausmeer-
schweinchens, Cavia apera f. porcellus
(L. ) . Z. Tierpsych. 21: 602-641.
1967]
Poglayen-N euwall: Marking Behavior of the Kinkajou
141
Landowski, J.
1961. Breeding the Pine Marten ( Martes martes
L. 1758) in Captivity. Int. Zoo Yearbook,
vol. III. Zool. Soc. London.
Pocock, R. I.
1921. The External Characters and Classification
of the Procyonidae. Proc. Zool. Soc. Lon-
don; Pt. 1: 389-422.
Poglayen-Neuwall, I.
1962. Beitrage zu einem Ethogramm des Wick-
elbaren (Potos flavus Schreber). Z. Sau-
getierkunde 27 (1): 1-44.
Poglayen-Neuwall, I. & I. Poglayen-Neuwall
1965. Gefangenschaftsbeobachtungen an Maki-
baren ( Bassaricyon Allen 1876). Z. Sau-
getierkunde 30 (6): 321-366.
Richardson, W. B.
1942. Ring-tailed Cats ( Bassariscus astutus) :
TheirGrowth and Development. J. Mamm.
23: 17-26.
Schultze-Westrum, Th.
1964. Nachweis differenzierter Duftstoffe beim
Gleitbeutler, Petaurus breviceps papuanus
Thomas. Die Naturwissenschaften 61 (9):
226-227.
Walther, F.
1958. Zum Kampf-und Paarungsverhalten eini-
ger Antilopen. Z. Tierpsych. 15 (3): 340-
380.
EXPLANATION OF PLATES
Plate I
Female kinkajou marking with mandibular gland.
Plate II
Female using mandibular gland for marking.
Plate III
Male marking with throat gland.
POGLAYEN-NEUWALL
PLATE I
FIG. 1
ON THE MARKING BEHAVIOR OF THE KINKAJOU ( POTOS FLAWS SCHREBER)
POGLAYEN-NEUWALL
PLATE II
FIG. 2
ON THE MARKING BEHAVIOR OF THE KINKAJOU ( POTOS FLAWS SCHREBER)
POGLAYEN-NEUWALL
PLATE III
FIG. 3
ON THE MARKING BEHAVIOR OF THE KINKAJOU ( POTOS FLAWS SCHREBER)
[1966]
Zoologica: Index to Volume 51
143
INDEX
Names in bold lace indicate new
genera, species or subspecies,- num-
bers in bold face indicate illustra-
tions,- numbers in parentheses are
the series numbers of papers con-
taining the plates listed immediately
following.
B
Basiliscus basiliscus, 91
Blarina, 55
Boa constrictor, 29, 31, 33
C
Calappa convexa, 12
saussurei, 12
Centetes, 55, 56
Centroprisfes striatus, (9) PI. VI
Clythrocerus edentalus, 6, 7
Cryptocaryon irritans, 97, (9)
Pis. I- VII
Cycloes bairdii, 13
D
Delphinus delphis, 74
Dromidia sarraburei Rathbun, 4
Dynomene Ursula, 5
£
Ebalia magdalenensis, 8
Echinops, 50, 56
telrairi, 56
Erinaceus, 56
europaeus, 55
Ethusa ciliatifrons, 6
lata, 6
mascarone panamensis, 5
H
Hemicentetes, 55
Hepalella arnica, 14
Hepatus bossmanni, 14
Holocentrus ascensionis, (10) Pi. I
Hypoconcha panamensis, 4
I
Ichlhyophthirius marinus, 97
Iliacantha hancocki, 11
schmitti, 1 1
L
Lebistes reticulalus, 77
Leucosilia jurinei, 9
Lithadia cumingii, 8
M
Macaca mulafla, 17, (2) Pis. I-IV
Microgale, 55
Mursia gaudichaudii, 13
O
Odobenus r. rosmarus, 103, (10)
Pis. I-V
(10) recording
Orcinus orca, 59, (5) Pis. I-VIII, 71
(6) Pis. I-VI
Osachilia lata, 14
levis, 15
sona, 15
P
Parahaplomelroides basiliscae, 91,
(8) Pis. I-II
Persephone edwardsii, 9
townsendi, 9
Polos flavus, 137, (12) Pis. Mil
R
Randallia agaricias, 10
bulligera, 10
minula, 11
ornata, 10
S
Scarus guacamaia (9) PI. VII
Solenodon paradoxus, 49, Pis. I-II
Sorex, 55
Stenella graffmani, 74
Slenotomus chrysops, (9) Pi. Ill
T
Tupaia, 55
Tursiops truncalus, 72
U
Uhlias ellipticus, 8
X
Xiphophorus, 107
hellerii, 117
hellerii guentheri (11) Pis. IV & V
maculatus, 110, 119 (11) PL III, VI
Xiphophorus milleri, 113, 122 (11)
PL II
montezumae, 113, 123
m. montezumae, (11) PL V
pygmaeus nigrensis, 123, (11)
PL I
varialus, 111, 121
v. xiphidium, (11) Pis. V & VI
v. varialus, (11), PI. I
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