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TULAWS STUDIES Iv ZOOLOGY
VOLUME 2 1964-1965
TULANE UNIVERSITY NEW ORLEANS
TULANE STUDIES IN ZOOLOGY is devoted primarily to the zoology of the waters and adjacent land areas of the Gulf of Mexico and the Caribbean Sea. Each number is issued separately and contains an individual monographic study, or several minor studies. As volumes are completed, title pages and tables of contents are distributed to institu- tions receiving the entire series.
Manuscripts submitted for publication are evaluated by the editor or associate editor and by an editorial committee selected for each paper. Contributors need not be members of the Tulane University faculty.
The editors of Talane Studies in Zoology recommend conformance with the principles stated in chapters I and II (only) of the Style Manual for Biological Journals, 2nd ed., published in 1964 by the American Institute of Biological Sciences, Washington, D. C.
Manuscripts should be submitted on good paper, as original typewritten copy, double- spaced, and carefully corrected. Two copies, carbon or other suitable reproduction, must accompany the original to expedite editing and assure more rapid publication. Legends for figures should be prepared on a separate page. Illustrations should be proportioned for one or two column width reproductions and should allow for insertion of legend if occupying a whole page.
An abstract not exceeding three percent of the length of the original article must ac- company each manuscript submitted. This will be “transmitted to Biological Abstracts and any other abstracting journal specified by the writer.
The editors also recognize the policy adopted by the Federal Council for Science and Technology, and endorsed by the Conference of Biological Editors, that page charges for publication of scientific research results in scientific journals will be budgeted for and paid as a necessary part of research costs under Federal grants and contracts. Accord- ingly, writers crediting research grant support in their contributions will be requested to defray publication costs if allowable under the terms of their specific awards.
Illustrations and tabular matter in excess of 20 percent of the total number of pages may be charged to the author, the levy applied being the excess above 10-point typesetting costs.
Exchanges are invited from institutions publishing comparable series but subscriptions are available if no exchange agreement can be effected. Separate numbers or volumes can be purchased by individuals, but subscriptions are not accepted. Remittance should accompany orders from individuals. Authors may obtain separates of their articles at cost.
Address all communications concerning manuscripts and editorial matters to the editor; Communications concerning exchanges, and orders for individual numbers to the Meade Natural History Library.
When citing this series authors are requested to use the following abbreviations: Tlane Stud. Zool.
Price for this volume: $3.50.
Harold A. Dundee, Edztor Gerald E. Gunning, Associate Editor Department of Biology, Tulane University, New Orleans, Louisiana 70118, U.S.A. Harold A. Dundee, Director Meade Natural History Library, James R. Reed, Jr. Tulane University, Assistant to the Editors New Orleans, Louisiana 70118, U.S.A.
CONTENTS OF VOLUME 12
NUMBER
ile
bo
(J)
A NEW BRANCHIOBDELLID (ANNELIDA) FROM COSTA RICA Perry C. Holt
THE RIVER CRABS OF COSTA RICA, AND THE SUBFAMILIES OF THE PSEUDOTHELPHUSIDAH
Alfr ed E. Galler
MYSIDOPSIS ALMYRA, A NEW ESTUARINE MYSID CRUSTACEAN FROM LOUISIANA AND FLORIDA...
ituomes E. ipomen
AGE DETERMINATION OF THE COTTON RAT (SIGMODON HISPIDUS) Robert K. Chipman
DIGENETIC TREMATODES OF MARINE FISHES FROM APALACHEE BAY, GULF OF MEXICO.
“FusdiM. Nahhae and Robart Bo Short
HISTOLOGY, DEVELOPMENT, AND INDIVIDUAL VARIATION OF COM- gg ee VI Fe ODE) EAC UA, Oe aos. 2 ee Se oe ee
Andrew A. Ar he Norman C. Negus, and Martha Sapp Downs
ETHEOSTOMA DITREMA, A NEW DARTER OF THE SUBGENUS OLIGO- CEPHALUS (PERCIDAE) FROM SPRINGS OF THE ALABAMA RIVER BASIN IN ALABAMA AND GEORGIA__
oun s. pameces Fal Ron D. Suttkus
PARASITES FROM LOUISIANA CRAYFISHES_____ wae Fr sali Sorandar es- Bee mal
A NEW SUBSPECIES OF THE CRAWFISH ORCONECTES LEPTOGO- NOPODUS FROM THE OUACHITA RIVER DRAINAGE IN ARKANSAS
Jobe Mitzpatrick, J:
ECOLOGICAL DISTRIBUTION AND ACTIVITY PERIODS OF BATS OF THE MOGOLLON MOUNTAINS AREA OF NEW MEXICO AND ADJA- SURI Maem NOLO) Are ee Se ee ee ee ee
Clyde Tones
ETHEOSTOMA (OLIGOCEPHALUS) NUCHALE, A NEW DARTER FROM AMON STONE: SP RENG-UN At AB A MAC 1.2) as eee eee
William Mile: Howell aad Richard Dale Caldew ell
EARLY DEVELOPMENTAL STAGES OF THE ROCK SHRIMP, SICYONIA BREVIROSTRIS STIMPSON, REARED IN THE LABORATORY.
Harry L. Cook and M. Hee Mur Diy
FISHES TAKEN IN MONTHLY TRAWL SAMPLES OFFSHORE OF PI- NELLAS COUNTY, FLORIDA, WITH NEW ADDITIONS TO THE FISH FAUNA OF THE TAMPA BAsYaeA Rin Ate a oe
Martin A. Moe, Jr. ae Geonee T. Martin
PAGE
if
39
51
87
93
101
109
129
Printed in the U.S. at New Orleans, by HAUSER-AMERICAN:
TULANE STUDIES IN ZOOLOGY
Volume 12, Number 1 August 21, 1964
A NEW BRANCHIOBDELLID (ANNELIDA) FROM COSTA RICA
PERRY C. HOLT, DEPARTMENT OF BIOLOGY AND VIRGINIA AGRICULTURAL EXPERIMENT STATION, VIRGINIA POLYTECHNIC INSTITUTE, BLACKSBURG, VIRGINIA Pen 2
THE RIVER CRABS OF COSTA RICA, AND THE SUBFAMILIES OF THE PSEUDOTHELPHUSIDAE ALFRED E. SMALLEY,
DEPARTMENT OF ZOOLOGY, TULANE UNIVERSITY, NEW ORLEANS, LOUISIANA Dinca
MYSIDOPSIS ALMYRA, A NEW ESTUARINE MYSID CRUSTACEAN FROM LOUISIANA AND FLORIDA THOMAS E. BOWMAN, DIVISION OF MARINE INVERTEBRATES,
SMITHSONIAN INSTITUTION, WASHINGTON, D.C. 20560 p. 15
TULANE UNIVERSITY NEW ORLEANS
TULANE STUDIES IN ZOOLOGY is devoted primarily to the zoology of the waters and adjacent land areas of the Gulf of Mexico and the Caribbean Sea. Each number is issued separately and contains an individual monographic study, or several minor studies. As volumes are completed, title pages and tables of contents are distributed to institutions ex- changing the entire series.
Manuscripts submitted for publication are evaluated by the editor or associate editor and by an editorial committee selected for each paper. Contributors need not be mem- bers of the Tulane University faculty.
The editors of Tulane Studies tn Zoology recommend conformance with the principles stated in chapters I and II (only) of the Style Manual for Biological Journals published in 1960 by the American Institute of Biological Sciences, Washington, D. C.
The editors also recognize the policy adopted by the Federal Council for Science and Tech- nology, and endorsed by the Conference of Biological Editors, that page charges for publica- tion of scientific research results in scientific journals will be budgeted for and paid as a necessary part of research costs under Federal grants and contracts. Accordingly, writers crediting research grant support in their contributions will be requested to defray publica- tion costs if allowable under the terms of their specific awards.
Illustrations and tabular matter in excess of 20 percent of the total number of pages may be charged to the author, the levy applied being the excess above 10-point typesetting costs.
Manuscripts should be submitted on good paper, as original typewritten copy, double- | spaced, and carefully corrected. Two carbon copies in addition to the original will help expedite editing and assure more rapid publication.
An abstract not exceeding three percent of the length of the original article must accom- pany each manuscript submitted. This will be transmitted to Biological Abstracts and any other abstracting journal specified by the writer.
Separate numbers or volumes may be purchased by individuals, but subscriptions are not accepted. Remittance should accompany orders from individuals. Authors may obtain copies for personal use at cost.
Address all communications concerning manuscripts and editorial matters to the editor; communications concerning exchanges, and orders for individual numbers to the Director, Meade Natural History Library.
When citing this series authors are requested to use the following abbreviations: Tulane Stud. Zool.
Price for this number: $0.50.
Harold A. Dundee, Editor
Gerald E. Gunning, Associate Editor Department of Zoology,
Tulane University,
New Orleans, Louisiana 70118, U.S.A.
Royal D. Suttkus, Director
’ Meade Natural History Library, Francis L. Rose, Tulane University, Assistant to the Editors New Orleans, Louisiana 70118, U.S.A.
TULANE STUDIES IN ZOOLOGY
Volume ie Number 1
“August De 1964
A NEW BRANCHIOBDELLID (ANNELIDA ) FROM COSTA RICA
PERRY C. HOLT, Department of Biology and Virginia Agricultural Experiment Station, Virginia Polytechnic Institute, Blacksburg, Virginta
ABSTRACT
A new branchiobdellid, Cambarincola smalleyi, from freshwater crabs of the family Pseudothelphusidae in Costa Ri- ca is described. A somewhat primitive member of the genus, this species is assumed to be a southern survivor of a Pleistocene migration of cambarine crawfishes and their epizoic commen- sals. It is hypothesized that the bran- chiobdellids survived in Costa Rica by passing from their former hests to the winners of the interglacial or post- Pleistocene competition between craw- fishes and crabs.
Branchiobdellid annelid worms, usually found as epizoic commensals on freshwater crawfishes of the family Astacidae, have been known from Mexico for some time (Rioje, 1940, 1943). They recently have been recorded from hosts other than astacid crawfishes (Hobbs and Villalobos F., 1958; Holt, 1963). The finding of them on fresh- water crabs of the family Pseudothelphusidae in Costa Rica by Alfred E. Smalley of Tulane University, is, nonetheless, worthy of note. First, this discovery adds another to the rapidly increasing list of crustacean families which serve as hosts for the branchiobdellids. In addition, the southward extension of their range from the Isthmus of Tehuantepec in Mexico through approximately seven degrees
of latitude to the highlands of Costa Rica is of some zoogeographical interest.
I am grateful to Dr. Smalley for making the four mature worms which he recovered from specimens of Psewdothelphusa tumt- manus Rathbun ( Pseudothelphusidae ) ayail- able to me for study and take pleasure in naming the new species of the genus Cam- barincola which they represent in his honor.
The procedures I use in the study of branchiobdellids have been described else- where (Holt, 1960). My studies are sup- ported by a grant, NSF-GB372, from the National Science Foundation.
Cambarincola smalleyi, n. sp. ( Figs. 1-4)
Diagnosis. Medium-sized members of the genus; head, approximately equal in diame- ter to that of segment I and the sucker, showing external evidence of being com- posed of four segments; prosomites of body segments not appreciably greater in diameter than metasomites; jaws homodont and iso- morphic, dental formula 6/6. Male repro- ductive system: the prostate about two-thirds the size of the spermiducal gland in length and diameter and histologically different from the latter, the prostate lacking an ental
EDITORIAL COMMITTEE FOR THIS PAPER:
G. E. GATES, Emeritus Professor and Visiting Professor, University of Maine, Orono,
Maine
WALTER J. HARMAN, Chairman, Department of Zoology, Louisiana State University,
Baton Rouge, Louisiana
WILLIAM R. MuRCHIE, Professor of Zoology, Flint College, University of Michigan,
Flint, Michigan
i)
bulb; the spermiducal gland without defer- ent lobes; the bursa elongate pyriform in shape. Female reproductive system: sperma- theca with a long ectal duct and an ental process.
Description, Since only four specimens of Cambarincola smalleyi are known, measure- ments are of little value. The type speci- men, however, as some indication of the size of these animals, has the following dimen- sions: total length, 2.82 mm, head length, 0.43 mm; head diameter, 0.29 mm; diame- ter, segment I, 0.40 mm; diameter, segment VI, O51 mm; diameter, sucker, 0.39 mm. The smallest specimen is 1.93 mm long.
The worms are somewhat corpulent in appearance; the greatest diameter of the holotype is one-sixth the total body length. The prosomites are not markedly greater in diameter than the metasomites, the body wall lacking the supernumerary muscles which produce this condition in some bran- chiobdellids. The sucker is of usual appear- ance and somewhat greater in diameter than the head or segment I.
The head shows obvious external signs of being composed of four segments (Fig. 1). Other branchiobdellids are known to have four vascular commissures in the head, but in C. smalleyi these commissures are readily apparent in the specimens mounted entire. The peristomium is, as usual, divided into dorsal and ventral “lips”; each lip is sub- divided by a slight median emargination. No oral papillae are present.
The jaws (Figs, 2 and 3) are unusual. The upper and lower jaws are similar in size and shape and the number of teeth (six) is the same for each jaw. The teeth, further- more, are subequal in size and their points form a gently curved arc in dorsal view. The jaws are sub-rectangular in dorsal view. They contrast, then, in these respects, with the triangular jaws with fewer teeth of most species of the genus. The dental formula of 6/6 is diagnostic of C. smalleyi.
The anterior nephridiopore, located as usual for the genus, is unusually prominent. The “bladder” and outlet duct formed by the junction of the two nephridia are thick- walled and glandular in appearance. Whether or not this reflects a real difference or the accidents of preservation cannot be deter- mined from the material available.
The prostate is composed of large vacuo- lated glandular cells, the spermiducal gland
Tulane Studies 1n Zoology
Vol. 12
anterior
es
025mm Fig-2
ei
025mm _. Fig-3
Figures 1-3. Cambarincola smalleyi, n. sp. 1. Outline drawing of type specimen. 2. Dor- sal jaw, paratype. 3. Ventral jaw, paratype.
of more densely granular cells, but the pros- tatic ental bulb is absent. The short, rela- tively thick, differentiated prostate without an ental bulb, a condition not described for any other branchiobdellid, is characteristic of C. smalleyz,
The spermiducal gland is perhaps some- what smaller in proportion to the total size of the animal than in most other species of the genus, but otherwise is not remarkable. The same statement can be made about the other organs of the male reproductive sys- tem.
A clitellum is present on segments VI and XI. The spermatheca has a rather long ectal duct and the spermathecal bulb has a small, but distinct, ental process (Fig. 4).
Type locality. Rio Hondura, eight miles north of San Jeronimo de Moravia, San Jose Province, Costa Rica.
Host. Pseudothelphusa tumimanus Rath- bun.
Disposition of types. The holotype, U. S. N. M. No. 30940 and one paratype, U. S. N. M. No. 30941 are deposited in the col- lections of the Division of Marine Inverte- brates, United States National Museum. One paratype is in the collection of Dr. Smalley at Tulane University and the remaining one is retained in my collections kept at the Vir- ginia Polytechnic Institute (PCH 1702).
Distribution. Cambartncola smalleyi is known only from the type locality.
No. 1
Remarks. Cambarincola smalleyi most closely resembles C. vitrea Ellis, 1919, in jaw structure but differs in the larger number of teeth borne by the jaws of the former and in the fact that the same number of teeth is present on each jaw. The general body form is like that of many species of the genus, differing in the more obvious signs of segmentation of the head. The male re- productive system in the histologically dif- ferentiated prostate is like that of Hoffman’s (1963) phtladelphica section of the genus, which includes C. vitrea, but differs in the absence of a prostatic bulb. One can specu- late that C. smalleyi is related in a greater or lesser degree to C. vitrea, a species which is widespread in the mid-continental plains region of the United States, or to C. meso- chorea Hoffman, 1963, likewise a mid- continental species. C. mesochorea has an undifferentiated prostate without an ental bulb, but has an ental spermathecal process, present in C. smalleyi and absent in C. vitrea.
Cambarincola smalleyi extends the known range of branchiobdellids almost 500 miles southward from southern Mexico to Costa Rica. Presumably it represents a montane survivor of a population representing the pre-Pleistocene North American fauna which moved southward during one of the Pleisto- cene glaciations. The species must have reached Costa Rica more recently than the late Miocene or early Pliocene closing of the Central American water gaps, if these gaps existed as is generally believed. The north- ern, temperate distribution of branchiob- dellids would argue against them being a part of the Neotropical Cenozoic fauna of North America.
Though the jaws of C. smalleyi are pres- ently thought to reflect a primitive bran- chiobdellid condition (Ellis, 1919) and the segmentation of the head is undoubtedly primitive, the species does not appear mark- edly primitive in other respects. The most reasonable conclusion would seem to be that it is a descendant of an already relative- ly advanced cambarincolid, pre-Pleistocene stock intermediate between Cambarincola mesochorea and C. vitrea.
Finally, some notice must be taken of the host of C. smalleyi, Presently, branchiob- dellids are known from astacine, cambaroi- dine, and cambarine crawfishes, isopods of the genus Asellus (Holt, 1963), and grapsid crabs (Hobbs and Villalobos F., 1958).
New Branchtobdellid
Wo
anterior
aos
ventral
Fig 4
-OSmm
Figure 4. Cambarincola smalleyi, lateral view of reproductive systems of type speci- men. Abbreviations: 6, bursa; ed, ejacula- tory duct; enp, ental process of spermathe- ca; pr, prostate; sb, bulb of spermatheca; sd, ectal duct of spermatheca; spg, spermi- ducal gland; vd, vas deferens.
Their occurrence on the tropical, freshwater, pseudothelphusid crabs takes them consider- ably beyond the range of the cambarine crawfishes which reach their southern limits in the Guatemalan highlands. Unquestion- ably, branchiobdellids are primarily com- mensals of astacid decapods, but no longer can be assumed to be confined to these hosts. Yet cambarine crawfishes must have carried them to Costa Rica, lost in competition with the tropical crabs, and passed their com- mensals to their conquerors.
The hypothesis that the branchiobdellids passed from crawfishes to crabs in southern Mexico and hence by repeated transfers and migrations southward to other crabs in Costa Rica may be, on the contrary, the correct ex- planation: it seems to me less likely.
Summary. A new branchiobdellid, Cam- barincola smalleyi, from freshwater crabs of the family Pseudothelphusidae in Costa Rica is described. Although a somewhat primitive member of the genus, it is not markedly so, and is assumed to be a southern survivor of a Pleistocene migration of cambarine craw- fishes and their epizoic commensals. The branchiobdellids presumably survived in
4 Tulane Studies n Zoology
Costa Rica by passing from their former hosts to the winners of the interglacial or post-Pleistocene competition between craw- fishes and crabs.
REFERENCES CITED
Evuis, Max M. 1919. The branchiobdellid worms in the collections of the United States National Museum, with descrip- tions of new genera and new species, Proc. U. S. Nat. Mus. ; 241-265.
Hopss, Horton H., JR. a. ALEJANDRO VIL- LALOBOS F. 1958. The exoskeleton of a freshwater crab as a microhabitat for several invertebrates. Virginia J. Sci. (N. S.) 9: 395-396.
HorrMaN, RICHARD L. 1963. A revision of the North American annelid worms of the genus Cambarincola (Oligochaeta: Branchiobdellidae). Proc. U. S. Nat. Mus. aI SS PAPAS Zale
Vol, 12
Hout, Perry C. 1949. A comparative study of the reproductive systems of NXironogi- ton instabilius instabilius (Moore) and Cambarincola philadelphica (Leidy) (An- nelida, Oligochaeta, Brancniobdellidae), J. Morph. 84: 535-572.
ia 1960. The genus Cerato- drilus Hall ‘(Branchiobde’ lidae, Oligochae- ta), with the description of a new species. Virginia Casals (ANS IS) ints GsiH7'7-
Pe oe eee ee 1963. A new branchiob- dellid (Branchiobdellidae: Cambarinco- la). J. Tennessee Acad. Sci. 38: 97-100.
RioJA, ENRIGUE, 1940. Estudios Hidrobi- ologicos II. Datos sobre los Branchiob- dellidae de Xochimileco, Zempoala y Tex- coco, Anales del Instituto de Biologia 11 (1): 249-253.
~ _........ 1948. Estudios Hidrobi- ologicos IX. Anotaciones sobre branquiob- delidos Mexicanos. Anales del Instituto de Biologia 14(2): 541-545.
THE RIVER CRABS OF COSTA RICA, AND THE SUBFAMILIES OF THE PSEUDOTHELPHUSIDAE ALFRED E. SMALLEY, Department of Zoology, Tulane University, New Orleans, Louisiana
ABSTRACT
The Costa Rican river crabs of the family Pseudothelphusidae are reviewed and their gonopods described. Two sub- families are recognized in the family Pseudothelphusidae; the new subfami- ly Epilobocerinae for Hpilobocera, and Pseudothelphusinae for the remaining four genera. Epilobocera fuhrmanni is a Pseudothelphusa. New subgenera proposed for Pseudothelphusa are: Ach- lidon, for P. agrestis; Allacanthus, for P. pittieri; Megathelphusa, for P. mag- na and P. richmondi; Ptychophallus, for P. tristani, P. montana, P. tumi- manus, P. exilipes, and P. xantusi. P. convexa is relegated to the synonymy of P. montana,
I. INTRODUCTION
The American river crabs are an important component of the fauna of tropical fresh waters. There are numerous species, most of which have restricted ranges. Taxonomical- ly, the river crabs have been neglected in spite of the many interesting systematic and zoogeographic problems posed by them. Most of the Pseudothelphusidae were de- scribed by Rathbun, who also produced the most recent monograph of the family (Rath- bun, 1905). Since that time, studies have been sporadic, usually incidental to other research, or included in faunistic papers. Furthermore, earlier students did not recog- nize the importance of the male pleopods (gonopods) in classification. Rathbun was inconsistent in the use of gonopod char- acters. Sometimes she provided good figures, but at other times she ignored the gonopods, even when the description was based on a male.
Rathbun was well aware of the inade- quacy of using the carapace for taxonomic distinctions in the genus Psewdothelphusa, and also realized the specific distinctiveness of the gonopods, but nevertheless chose to base her keys and descriptions on non- gonopodal features. As a result, many de- scriptions are based on females, although species of Pseudothelphusa should never be described from females alone. Even if a species can be distinguished without using the gonopods, its relationships to other spe- cies and genera will remain unknown if this practice is followed.
In this paper, the five genera of the Pseudothelphusidae are divided into two sub- families and the Costa Rican Pseudothel- phusa into subgenera on the basis of gono- pod structure. In addition, supplementary descriptions are given for the Costa Rican species.
There are types of all the Costa Rican species in the U. S. National Museum.
II]. COLLECTION LOCALITIES
Since most of the Pseudothelphusidae have restricted ranges, the localities where they are collected assume considerable impor- tance. All of the Pseudothelphusidae known from Costa Rica were described by Rath- bun (1893, 1896, 1898), from specimens provided by various collectors. The locality data supplied by these collectors are inade- quate, usually including the name of the nearest village or town and the altitude, but never the province. Since finding the lo- calities where these collections were made
EDITORIAL COMMITTEE FOR THIS PAPER:
FENNER A. CHACE, JR., Senior Scientist, Department of Zoology, United States Na-
tional Museum, Washington, D.C.
Dr. L. B. HoLttHuts, Rijksmuseum van Naturlijke Historie, Raamsteeg 2, Leiden,
The Netherlands
HAROLD E. VOKES, Professor and Chairman, Department of Geology, Tulane Uni-
versity, New Orleans, Louisiana
6 Tulane Studies n Zoology
proved to be a difficult task, the results of my search are listed below. Sr. Don Salvador Jiménez-Canossa was most helpful in resolv- ing difficult problems. The gazetteer by Selander and Vaurie (1962) is very useful, and would have greatly lightened my task had it been available sooner.
Aguabuena. Puntarenas Prov., near the Panamanian border, 8° 44’ N, 82° 56’ W.
Boruca. Puntarenas Prov., 9° 01’ N, 83° PAW
Cachi. CGartago Prov. 9° 49° N, 83° 48’ W.
Cariblanco. Heredia Prov., 10° 10’ N, 84° 10’ W.
Chemin de Carrillo. Junction of San José, Cartago, and Limon Provinces, 10° 10° N, 83°57 W.
El Coronel. Border of San José and Car- tago Provinces, on the Rio Sucio, 10° 7’ N, 832 oo WE
Java. Selander and Vaurie list a “Que- brada de Java,” Puntarenas Prov., 8° 52’ N, 83° O17 W.
La Palma. There are several “La Palmas” in Costa Rica. According to the altitude of 1500 meters, the one cited by Rathbun is probably Alto La Palma, San José Prov., 10° 03’ N, 83° 58’ W.
Pacaca, Rodeo. Pacaca is an older name for Villa Colon: Rodeo is probably the name for a farm or ranch. San José Prov., 9° 56’ N, 84° 16’ W.
Palmar. Palmar Norte or Palmar Sur, Puntarenas Prov., 8° 57’ N, 83° 27’ W.
Pozo Azul. Guanacaste Prov., 10° 12’ N, 84° 56’ W
Rio Maria Aguilar. A tributary of the Rio Virilla, probably near the city of San José, San José Prov., 9° 56’ N, 84° 05’ W.
Rio Torres. Also a tributary of the Rio Virilla, probably near San José (see previous item ).
San Carlos. A region, or district, in Ala- juela Province, drained by the Rio San Carlos.
Santa Clara Jiménez. Heredia Prov., 10° 13’ N, 83° 43° W.
Santa Domingo, Gulf of Dulce. renas Prov., 8° 32’ N, 83° 17’ W.
Surubres, near San Mateo, Alajuela Prov., 9° 56’ N, 84° 30° W.
La Flor, Torito. Cartago Prov., 9° 53’ N, 83° 50’ W.
Punta-
Vo 2
Ill. KEY TO THE SPECIES OF COSTA RICAN PSEUDOTHELPHUSIDAE
The following key is based principally on gonopod morphology. There are no funda- mental differences between the gonopods of Pseudothelphusa and Potamocarcinus, and the gonopod characteristics of Potamocarcin- ws included in the key should not be con- sidered of generic importance. Terminology follows Smalley (1964).
1. Antero-lateral teeth of carapace
large and spiniform; ventral
border of front of carapace
not visible from above; mar-
ginal process of gonopod ex-
tending beyond apex.
Saige WOE Potamocarcinus nicaraguensis Antero-lateral teeth small or
minute; ventral margin of
front visible from above;
marginal process of gonopod,
when evident, not extending
beyond apex. Pseudothelphu-
$0) 22 wd ee Tip of gonopod not folded, api-
cal spines pointing apically ;
gonopod simple in structure.
__Pseudothelphusa (Achlidon) agrestis Tip of gonopod folded; at least
some of the apical spines
pointing: cephalad === aaa 3 Patch of well-defined, short,
sub-apical spines on cephalic
surface of gonopods, in addi-
tion to apical spines.
Pseudothelphusa (Allacanthus) pittieri Apical spines only, ey 4 4. Large mesial tooth near apex
of gonopod; shaft without broad lateral process. Sub- genus Megathelphusa 5 Apical part of gonopod broad, joined to rest of gonopod by narrow peduncle; usually with broad lateral processes. Sub- genus Ptychophallus 5. Marginal process of gonopod curving laterad, ending at tip of gonopod.
bo
Go
pel er ee Pseudothelphusa magna Marginal process curving: mesi-
ad, ending just short of tip
of gonopod.
ne ts BIE Pee, Pseudothelphusa richmondi 6. Lateral subapical process of
gonopod not broad, not ex-
ceeding apical process; mesi-
al process subapical.
-Pseudothelphusa xantusi
Lateral subapical process broad,
exceeding apical process C7 Mesial apical process of gono-
pod broad, hatchet-shaped.
= __Pseudothelphusa tristani Mesial’ apical process narrow,
finger-like
<I
8. Lateral subapical process of eupeue not bilobed. Pseudothelphusa exilipes
lateral subapical | process _ bi- lobed _ ie ie ae 9)
9. Mesial apical process satae gono- pod, seen in marginal view, nearly as long as lateral api- cal process; proximal lobe of subapical process sub-acute. Small species. _Pseudothelphusa montana
Mesial subapical process much shorter than lateral process; proximal lobe of subapical process broadly rounded. Large species.
Pseudothelphusa tumimanus
IV. SYSTEMATIC ACCOUNT
Most of the specimens on which this ac- count is based were collected by me in Costa Rica during the summer of 1962, and were identified by comparison with types in the U.S. National Museum. Specimens from the U. S. National Museum are indicated by the initials USNM. The drawings of Epilobo- cera cubensis are from a specimen borrowed from the Museum of Comparative Anatomy, Harvard University. All other specimens are at Tulane University.
Measurements, where given, are for great- est carapace width and median carapace length in millimeters, of the largest male examined. Immature males too small to be identified with certainty are simply included with the large males in the same collection and listed as “imm.”. Some question of identity applies to any female Psewdothel- phusa, and they also are grouped with the identified males. Specimens so small that the pleopods are not developed are desig- nated “imm.”. A number of collections did not include any identifiable specimens and are omitted. Figures in parentheses indicate the altitude in meters. Localities are in Costa Rica unless otherwise specified.
Synonymies are given only if the species has been mentioned by anyone other than Rathbun (1896, 1898, 1905), and Young (1900).
Pseudothelphusa tuberculata Rathbun is omitted from this account. There is a female from Boruca, in the U. S. National Museum, determined by Rathbun, but I believe that this is an erroneous identification, and that the range of P. tuberculata should be re- stricted to Guatemala. The same remarks
Costa Rican River Crabs 7/
apply to a female Pseudothelphusa vene- zwelensis Rathbun from La Palma.
In the illustrations of the gonopods, the caudal surface is always oriented so that the margin can be identified as a line extending the length of the gonopod, with a proximal tuft of setae. The cephalic surface is oriented so that at least some of the apical spines point directly toward the observer. In most Costa Rican species, the apical spines are directed cephalad, although this is not the case with many, if not most, Pseudothel- phusidae. Most gonopods are more or less flattened caudocephalad, but the drawings: of the caudal and cephalic surfaces are not necessarily at 180 degrees, so the gonopod may appear broader in one view than in the other. A standard orientation for gonopod drawings is desirable because figures of complex gonopods are difficult to compare if they are drawn from different sides. Best results are obtained if the right gonopod is removed from the crab for examination, and subsequently kept in a small cotton-stoppered vial in the jar with the crab.
The Subfamilies of the Pseudothelphusidae
Bott (1955) divided the old family Pota- monidae into the three families Potamonidae, Pseudothelphusidae, and Deckiniidae, and his arrangement is adopted here, although with some reservations. All the American river crabs, except the genus Trichodactylus Latreille, 1825, belong in the family Pseudo- thelphusidae, which is restricted to the New World.
The relationships among the genera of the Pseudothelphusidae have undergone vari- Ous treatments in the past as summarized by Colosi (1920). Gonopod morphology has not been used in previous classifications at the generic level, even though some car- cinologists, notably Alcock (1910), Colosi (1920), and Bott (1955), have recognized the importance of the gonopods in distin- guishing the Pseudothelphusidae from other river crabs. The Pseudothelphusidae can be divided into two readily distinguishable sub- families on the basis of gonopod structure alone.
Pseudothelphusinae Ortmann, 1893
Pseudothelphusidae with gonopods armed at the tip with a group of apical spines, con- centrated in a distinct area at the aperture of the sperm channel. Type genus, Psemdo-
8 Tulane Studies n Zoology
thelphusa de Saussure, 1857. Other genera; Potamocarcinus WH. Milne-Edwards, 1853; Rathbunia Nobili, 1896, and Typhlopseudo- thelphusa Rioja, 1952.
Epilobocerinae, new subfamily
Pseudothelphusidae with gonopods armed at the tip with both a patch of apical spines at the aperture of the sperm channel, and also with large, scattered spines. Type and only genus, Epilobocera Stimpson, 1860.
The difference between the gonopods of the two subfamilies can readily be seen by comparing Epilobocera cubensis Stimpson, 1860 (Figs. 16-17) with any Pseudothel- phusa. Zimmer (1914) described a river crab from Columbia and placed it in Epzlo- bocera on the basis of non-gonopodal struc- tures. Fortunately, Zimmer provided good illustrations of the gonopod, which clearly show that Epilobocera fuhrmanni Zimmer should be Psewdothelphusa fuhrmanni (Zim- mer ).
Genus Potamocarcinus H. Milne-Edwards 1853
Potamocarcinus ntcaraguensis Rathbun
Rathbun, 1893, p. 656; Colosi, 1920, p. 17; Smalley, 1964, p. 29.
Specimens examined: Trinidad, Heredia Prov., border between Costa Rica and Nica- ragua; 1 May 1960; 2 @ 2.—Resguardo, Guanacaste Prov., near Nicaraguan border; 7 Feb. 1960; 4 ¢ ¢.
Margin of gonopod straight; caudal pro- cess prominent, extending well beyond apex; a prominent mesial apical tooth; two smaller, spiniform, cephalic teeth placed close to- gether; without lateral setae.
This species can be distinguished in the field from all other Costa Rican Pseudo- thelphusidae by the prominent spiniform anterolateral teeth of the carapace. If I had only the gonopod before me, I would place this species in Psewdothelphusa (Megathel- phusa). A large species, found in lakes, rivers, and streams in Nicaragua and Costa Rica. Largest female examined by Rathbun, 95 x 60.1; largest Tulane male, 75.1 x 45.1.
Genus Pseudothelphusa de Saussure, 1857
Rathbun made two subgeneric divisions of the large genus Pseudothelphusa, one based on gonopod structure (1898, p. 513), the other mostly on structure of the carapace,
third maxillipeds, and chelae (1905, p. 27
Volz
ff.). The two arrangements result in dif- ferent classifications, but neither was formal- ly proposed, and there are at present no sub- genera recognized for Pseudothelphusa, Rathbun’s grouping according to gonopod structure is, in my Opinion, the more satis- factory of the two. A number of changes must be made in Rathbun’s gonopod groups, but for the Costa Rican Pseudothelphusa, only the following changes are necessary: (1) remove P. pittieri from Group 1, and erect for it a monotypic subgenus, (2) add P. extlipes to Group 2, and (3) remove P. agrestis from Group 6 and erect for it a monotypic subgenus.
The phylogeny, evolution, and zoogeog- raphy of Pseudothelphusa cannot profitably be studied without a subgeneric classifica- tion, for which the most satisfactory criteria are gonopod characters. Subgenera are there- fore proposed for the Costa Rican Pseudo- thelphusa. Subgenera can similarly be erected for other species groups of Pseudo- thelphusa, but a large number of unresolved taxonomic problems prevent further exten- sion of the classification at this time.
Achlidon, new subgenus
Gonopod simple in structure, curving mesiad, with expanded apex. Blunt, mesial subapical tooth the only process. Apical spines directed apically, apex without folds. Margin curving mesiad, emerging near cephalic surface. Type and only species, P. agrestis. Achlidon (masc.)—unornamented.
Pseudothelphusa ( Achlidon) agrestis Rathbun, 1898
Specimens examined: La Flor, near Torito, Cartago Prov., 1 6,1 2, the types (USNM). Illustrated by Rathbun (1898, p. 515). The shape of the gonopod is quite different from the other species in Rathbun’s Group 6.
Allacanthos, new subgenus
Gonopod and margin straight, apex folded, sperm channel emerging on cephalic sur- face. With a blunt, mesial, apical lobe, and a small, sharp, apically directed lateral lobe bearing sparse apical spines. Cephalic and lateral surfaces with well defined area of small regularly spaced spines; row of scat- tered spines on mesial surface of shaft. Type and only species, P. pittiert. Allacanthos (fem. )—other spines.
No. 1
Pseudothelphusa ( Allacanthos) pittiert Rathbun, 1898 ( Figs. 1-3) Specimens examined: Agua Buena, Punta- renas Prov.; 2 ¢ 6,1 2, the types (USNM). A small species (19.1 x 11.9), with the characters of the subgenus. A small tubercle at the base of the moveable finger of the chela is distinctive. Rathbun thought the gonopod of P, pittieri to be similar to those of a group of Mexican and West Indian species (Group 1), but in fact it is unique.
Megathelphusa, new subgenus
Gonopod with large mesial tooth, visible in both cephalic and caudal aspects, and two smaller cephalic teeth, varying in position and shape. Marginal process not extending beyond apex, sperm channel emerging from beneath fold of tip of gonopod. Apical spines small, facing partly apically, partly cephalad. Setae prominent, particularly mesial setae. Two tubercles at base of mov- able finger of chelae, forming long area which is light-colored in fresh specimens. Type-species, Pseudothelphusa magna, other species, P. richmondi. Megathelphusa (fem.) —large river crab.
Rathbun separated P. richmondi and P. magna by the characters of the chelae, stating that the tubercle at the base of the fingers is lacking in P. richmondz, but in fact the two species have very similar chelae. Both species of Megathelphusa are widely dis- tributed, in contrast to most Costa Rican Pseudothelphusidae.
Pseudothelphusa (Megathelphusa) magna Rathbun, 1896
Holthuis, 1954, p. 33; Bott, 1956, p. 230; Smalley, 1964, p. 29.
Specimens examined: 11.5 mi. NNW Li- beria, Guanacaste Prov.; 9 Feb. 1960; 1 4, 1 2.—Rio Virilla, 2 mi. W San José, San José Prov.; 11 Feb. 1960; 1 ¢.—Same Jo- cality; 24 Jan. 1961; 2 64,1 2,limm. é. —Rio Irigaray, on Pan Am Highway, Guan- acaste Prov.; 21 Jan. 1961; 1 2.—Rio Las Vueltas, E of Nicaraguan border, Guanacaste Prov.; 21 Jan. 1961; 1 6,1 9, 1imm. 6.— Small stream, E bank Rio Grande de Tar- coles, 3 mi. E Atenas, Alajuela Prov. (580 m); 11 July 1962; 3 $3,3 22,1 imm— Small stream, 0.3 mi. S above locality; 11 July 1962; 3 63,1 2,3 imm. ¢ ¢6—Rio
Costa Rican River Crabs 9
Ciruelas, 0.2 mi. S RR crossing at Ciruelas, Alajuela Prov. (800 m); 20 July 1962; 466. 4 O89. 2 timm:
Two cephalic teeth not separate, consist- ing of two teeth of single medially directed process. Gonopods similar to illustrations by Holthuis and Bott; some variation shown by mesial apical process.
P. magna is one of the largest species of Pseudothelphusidae, although no one has re- ported another specimen of the heroic size of one of Rathbun’s syntypes (135 x 84); the largest Tulane male is 86.5 x 52.3. The specimens from Ciruelas were under large rocks in a nearly dry gully, and were found in pairs, probably copulating. Known from Costa Rica to Guatemala.
Pseudothelphusa (Megathelphusa) richmondi Rathbun, 1893 ( Figs. 4-6) Nobili, 1897, p. 3 (but the same speci- mens listed by Colosi, 1920, p. 20, as P. sp.); Boone, 1929, p. 567.
Specimens examined: Tributary of Rio Escondido, 50 mi. from Bluefields, Nica- ragua (probably near the town of Rama); 1 6, the holotype (USNM)—1.1 mi. N Turrialba, Cartago Prov. (600 m); 18 July 1962: 9 66,15 29,3 imm)> ¢.¢.
Cephalic teeth uneven in size, proximal twice size of distal, more pointed. Setae prominent, particularly mesial setae. Row of short setae on cephalic surface just below apical spines. Smaller than P. magna; holo- type, 49 x 32.5; largest Tulane male, 62.7 x 40.6.
The Costa Rican specimens were found in a coffee plantation on a wet hillside. Ditches had been dug to drain seepage from the field, and the crabs were burrowing into the sides of the ditches. P. richmondi is known from Nicaragua to Panama.
Ptychophallus, new subgenus
Gonopod with expanded tip connected to shaft by narrow peduncle. Lateral process of apical expansion larger than mesial, bearing apical spines; mesial process either narrow and fingerlike, or broad and hatchet-shaped. Most species with very broad subapical lat- eral process, usually bilobed. Apical spines directed cephalad. Marginal process folded cephalad, not projecting beyond apex. With- out marginal setae; lateral setae usually short, scattered; marginal and caudal setae present.
10 Tulane Studies 1n Zoology
Type-species, Pseudothelphusa tristant. Other species: P. montana, P. tumimanus, P. exilipes, and P. xantusit. Ptychophallus (masc.)—folded gonopod. P. ¢ristant 1s chosen as the type because it is common, easily recognized, and fairly typical. Psewdo- thelphusa colombiana Rathbun, 1893, from Panama and Mexico, should be placed in this subgenus on the authority of Rathbun (1893). Through an oversight, I did not examine the specimens in the U. S. National Museum on which Rathbun’s description was based. The only other record of this subgenus outside of Costa Rica is an errone- ous one for P. xantusi from La Guayra, Vene- zuela.
Pseudothelphusa (Ptychophallus) tristant Rathbun, 1896 ( Figs. 7-8 )
Specimens examined: La Mina, Rio Tor- res, San José Prov.; 1 4, the holotype (USNM).—1 mi. NW Tabarcia, San José Prov.; 20 June 1962; 2 64,5 2%, 3 imm. é $—same locality; 17 July 1962; 9 ¢ 4, 9 22,1 imm. ¢, 3 imm—2 mi. S. Villa Colon, San José Prov.; 29 June 1962; 2 4 2, 72 2.—same locality; 4 July 1962; 1 ¢, 3 22, 6 imm. 36 4¢—3 mi. E. Atenas, Alajuela Prov. (580 m); 7 July 1962, 4 ¢ 4, > 22°) 1 imm—O0O5 mi. S Cebadilla,-Ale- juela Prov; 1. July 1962; 6.6 6,9 2? 1 ovigerous), 6 imm. 6 6, 2 imm—2.7 mi. S El Roble, Heredia Prov. (1200 m): 13 July 1962; 2 66,1 2—2.5 mi. NE Santi- ago Puriscal, San José Prov., 17 July 1962, 26 646,16 22,4imm. 6 ¢.—0.8 mi. W Piedades, San José Prov.; 26 July 1962; 12 66,26 664, (4 with small crabs on abdo- men), 6 imm. ¢ ¢.
Only Ptychophallus with mesial apical lobe broad and hatchet-shaped. Proximal process of subapical lobe small, setae sparse. Fingers of larger chelae gaping in largest males, closed tightly in smaller males.
Abundant in the hills and mountains south of San José. P, tristani is more ter- restrial than P. tumimanus or P. montana. Typically, P. tristant is found under rocks or logs at the edge of streams, or even some distance from the stream edge. A cavity under the rock or log, filled with water, forms part of the crab’s burrow.
Vol. 12
Pseudothelphusa (Ptychophallus) montana Rathbun, 1898 ( Figs. 9-10) P. convexa, Rathbun, 1898.
Specimens examined: Alto La Palma, San José Prov.; 2 6 6), 2) So theseypes (USNM ).—Palmar, Puntarenas Prov., 1 ¢, holotype of P. convexa (USNM).—0.6 mi. S. Alto La Palma, San José Prov.; 9 July 1962: 2 26, 2 99, 0:2 “mr SeAlore Palma; 9 July 1962; 2 ¢ 6, 3 212) 2aane 6 6 —Rio Honduras, 3.0 mi. N continental divide, San José Prov.; 9 July 1962; 9 ¢ ¢.— 11 mi. NE Turrialba, Cartago Prov. (770 m); 6 July 1962; 4 ¢/6,5 2°, 6 timmy: d'd same locality; 21 July 1962; 13 64, 14 22,17 imm. ¢ 6.4 mi. E La Suiza, Car- tago: Prov.; 18 July 1962. i "cee imm. é.
Similar to P. tumimanus and P. exilipes. Medial process of gonopod long, slender. Subapical lateral process bilobed, proximal lobe acutely angled, caudal surface with dis- tinct depression between lobes. Small spe- eres (309 = 13ale):
Rathbun (1898) gave a confusing account of P. montana and P. convexa. The only dis- tinct difference between the types is that the two subapical lateral lobes of P. montana are not so distinct, the more proximal lobe not so acute, and the depression between the two lobes on the caudal surface more shallow. However, her figures (1898, p. 516 and p. 526) show the opposite, that is P. montana with a deep depression on the caudal surface. Since the gonopods of the material examined by me vary in the shape of the subapical lateral lobes and degree of concavity of the caudal surface, P. convexa should be considered a synonym of P. mon- tana. The name P. montana is chosen in preference to P. convexa because the speci- mens studied and illustrated in this work are from the type locality of P. montana and from the surrounding region.
The lack of females from Rio Honduras is due to the mixture of P. tamimanus and P. montana in the collection, and the diffi- culty of distinguishing the females. All the females were arbitrarily assigned to the more common P. twmimanus.
Found in streams, and under boards at an abandoned sawmill (northeast of Tur- rialba ).
No. 1
Pseudothelphusa (Ptychophallus) tumimanus Rathbun, 1898 ( Figs. 11-12)
Specimens examined: Cachi, Cartago Prov., 1 ¢, the holotype (USNM)—2 mi. S$ Cariblanco, Heredia Prov. (1200 m); 25 june 1962; 3 64,7 22, 1 imm—same lo- cality, 28 June 1962,4 66,5 22 (2 with juveniles on abdomen), 2 imm. ¢ ¢.—same locality; 14 July 1962; 10 ¢ 6,5 ? 2.—Rio Honduras, 3.0 mi. N continental divide, San José Prov.; 9 July 1962; 166 6, 31 22, 16 imm. 6 ¢, 5 imm—1.2 mi. SE El Roble, Heredia Prov. (1300 m); 13 July 1962; Peo. qmm. ¢ .
Lateral subapical process relatively larger than in other species of subgenus, tapering more gradually proximally, with scalloped border, and with short, heavy setae scattered along proximal part of lateral process.
A large species for the subgenus (Tulane, 60.3 x 35.7; holotype, after Rathbun, 70.2 x 42.2). Most specimens, and all the larger ones, were found in streams under rocks, or moving freely on the bottom.
Both Temnocephala and Branchiobdellidae were found on P. tumimanus, but they were mutually exclusive; the Temnocephala oc- curred on the population near Cariblanco, and the Branchiobdellidae on the crabs from Rio Honduras. The two populations are separated by about 18 miles of very rugged mountains. Hobbs and Villalobos (1958) report both groups of commensals occurring together on Pseudothelphusa lamellifrons Rathbun, 1893.
Pseudothelphusa (Ptychophallus) extlipes Rathbun, 1898 ( Figs. 13-14)
Specimens examined: Santa Maria de Dota, San José Prov.; 2 66,4 22 (USNM).
Mesial apical lobe of gonopod down- turned, more proximal than in P. montana; rounded distal lobe formed from margin at apex. Marginal and caudal setae prominent, individual setae long; long, scattered setae on lateral surface proximal to widest part of subapical lobe. Apical spines restricted to distal part of “patch”.
The holotype of P. exilpes is a female from El Coronel. The present description and illustrations are based on a male from Santa Maria de Dota, about 51 kilometers from El Coronel, and identified with the
Costa Rican River Crabs 11
type by Rathbun. Males from the type- locality would be very valuable. Collecting six miles from El Coronel yielded specimens only of P. tumimanus and P. montana. Simi- lar problems of confirming the identity of female types are common in the Pseudo- thelphusidae.
Pseudothelphusa (Ptychophallus) xantust Rathbun, 1893 CEive5)) Nobili, 1897, p. 3; Colosi, 1920, p. 19 (in the synonymy of P. fossor).
Specimens examined: Boruca, Puntarenas Prov.; 3 66,1 imm. (USNM).
Without mesial apical lobe, the lobe placed subapically instead. Lateral subapical lobes poorly developed.
Although P. xantusi is a rather aberrant member of the subgenus, the folded tip bears the apical spines exactly as in other species of Ptychophallus, and the lateral subapical lobes are typical in their shape and position, although not nearly as broad as in the other species.
The holotype of P. xantusi is a female, locality unknown, but probably from Mexico, and almost certainly not from Costa Rica. In my opinion this species will eventually have to be declared a species dubia and a new name assigned to the distinctive species from Boruca. However, judgment should be deferred until the river crabs of Mexico are much better known.
ACKNOWLEDGEMENTS
For help in the field, I am indebted to Dr. John DeAbate, Sr. Don Salvador Jiménez-Canossa, Dr. R. D. Suttkus, and especially my wife. Drs. Herbert W. Levi, F. A. Chace, Jr., and Raymond B. Manning were most helpful in loaning specimens; Dr. Manning was the subject of the greater part of these requests, with which he was most patient. This research was supported by a grant from the Systematics Section of the National Science Foundation (NSF- G20862), whose aid is gratefully acknowl- edged.
V. REFERENCES CITED
Aucock, A. 1910. On the classification of the Potamonidae (Thelphusidae). fee. Indian Mus. 5: 253-261.
BoongE, L. 1929. A collection of brachyuran Crustacea from the Bay of Panama and
Tulane Studies rn Zoology
IG “13 I4
Explanation of the Figures Right gonopods (usually distal portion only) and chelae of Costa Rican Pseudothelphusi- dae. 1-3, Pseudothelphusa pittieri; 4-6, P. richmondi; 7-8, P. tristani; 9-10, P. mon- tana; 11-12, P. tumimanus; 13-14, P. exilipes; 15, P. xantusi; 16-17, Epilobocera cuben- sis. Drawn to different scales.
No. 1
the fresh waters of the Canal Zone. Bull. Amer. Mus. Nat. Hist. 58: 561-583. Bort, R. 1955. Die Stisswasserkrabben von Afrika (Crust. Decap.) und ihre Stam- mesgeschichte. Ann. Mus. Roy. Congo Belge, C--Zool., Ser. III, III, Vol. 1(3): 209-352, pl. 1-30. _ 1956. Dekapoden (Crus- 3. Susswasser- Senck. Biol.
~ tacea) ¢ aus El Salvador. krabben (Pseudotelphusa). 37: 229-242.
CoLosi, G. 1920. I Potamonidi del R. Museo Zoologica di Torina. Boll. Mus. Zool. Anat. Comp. R. Univ. Torino 35(734): 1-39.
MILNE-Epwarps, H. 1853. Observations sur les affinités zoologiques et la classifica- tion naturelle des Crustacés. Ann. Sei. Nat., Zool. 18(3): 109-162.
Hopes, Horton H., and ALEJANDRO VILLA- LOBOS F.. 1958. The exoskeleton of a fresh- water crab as a microhabitat for several invertebrates. Virginia J. Sci. (N.S.) 9: 395-396.
HouruHuis, L. B. 1954. On a collection of decapod crustacea from the Republic of El Salvador (Central America). Zool. Verhandel., Leiden, No. 23: 1-43.
LATREILLE, P. A. 1825. Fiamilles naturelles du Regne animal. Paris.
Nosiui, G. 1896. Di un nuovo genere di Crostacei decapodi raccolto nel Darien dal dott. E. Festa. Boll. Bus. eee Anat. Comp. R. Univ. Torino 11(238) : 1-2
1897. Viaggio AG Dr. ~ Enrico Festa nella pepe ee dell’ Ecua- dor e regioni vicine. I decapodi terrestri e d’acqua dolce. Boll. Mus. Zool. Anat. Comp. R. Univ. Torino 12(275) : 1-6.
ORTMANN, A. E. 1893. Die Decapoden- Krebse des Strassburger Museums, mit besonderer Berucksichtigung der nov
Herrn Dr. Déderlein bei Japan und den
Costa Rican River Crabs 13
Liu-Kiu-Inseln gesammelten und zur Zeit im Strassburger Museum aufbewahrten Formen. VII. Theil. Zool. Jahrb., Syst. 7; 411-495.
RATHBUN, M. 1893. Descriptions of new species of American fresh-water crabs. Proc. U. S. Nat. Mus., 16: 649-661.
1896. Descriptions of two new species of fresh-water crabs from Costa Rica. Proc. U. S. Nat. Mus. 18:
Bee)
. . 1898. A contribution to the knowledge of the fresh-water crabs of America—The Pseudothelphusinae. Proc. U. S. Nat. Mus. 21: 507-537.
_. 1905. Les crabes d’eau
douce (Potamonidae). Nowv. Arch. Mus.
Hist. Nat. Paris, ser. 4, 72 159-321.
RiogA, E. 1952. Estudios carcinologicos. XXVIII. Descripcion de un nuevo género de potamonidos cavernicolos y ciegos de la Cueva del Tio Ticho, Comitan, Chis. An. Inst. Biol., Mexico 23(1-2): 217-225.
SAUSSURE, H. DE. 1857. Diagnoses de quel- ques Crustacés nouveaux des Antilles et du Mexique. Rev. Mag. Zool. 9(2) :304- 306.
SELANDER, R. and P. VAURIE. 1962. A gazet- teer to accompany the “Insecta” volumes of the “Biologia Centrali-Americana”’. Amer. Mus. Novitates, No. 20999: 1-70.
SMALLEY, A. 1964. A terminology for the gonopods of the American river crabs. Syst. Zool. 13:28-31.
STIMPSON, W. 1860. Notes on North Ameri- can Crustacea, No. 11. Ann. Lyc. Nat (East: Newent eliO=246e
YOUNG, C. 1900. The stalk-eyed Crustacea of British Guiana, West Indies and Ber- muda. Watkins, London.
ZIMMER, C. 1914. Beitrag zur Kentniss der Stisswasserdekapoden Kolumbiens. Mem.
Neuchdteloise des Sciences Naturelles 5: 1-8.
August 21, 1964
MYSIDOPSIS ALMYRA, A NEW ESTUARINE MYSID CRUSTACEAN FROM LOUISIANA AND FLORIDA THOMAS E. BOWMAN, Division of Marine Invertebrates, Smithsonian Institution,
W ashington,
ABSTRACT Mysidopsis almyra is described from Lake Pontchartrain, Louisiana, St. An- drews Bay, Florida, and Buttonwood Canal, Florida.
Two species of Mysidopsis are known from the Atlantic and Gulf of Mexico coasts of the United States. M. bigelows W. Tat- tersall (1926) occurs from New England to Louisiana, while M. furca Bowman (1957) is known only from the type-locality, off South Carolina. A third species, collected from brackish waters in Florida and Louisi- ana, is described below.
Mysidopsis almyra,' new species Figures 1-24
Mysidopsis sp., Darnell, 1961, pp. 555-556.
Description. Length, from anterior margin of rostrum to end of telson, varies seasonally: 8.1-9.4 mm in 6 adults collected 19 Feb. 1954, 4.2-5.3 mm in 5 adults collected 30 July 1953 in Lake Pontchartrain, Louisiana. Anterior margin of carapace broadly round- triangular, not produced between eyes as rostrum; anterolateral angles rounded; pos- terior margin evenly concave, thoracic somite 8 and a small portion of thoracic somite 7 exposed in dorsal view. Eye large, cornea kidney-shaped, without ocular papilla. Tel- son slightly shorter than pleonite 6, lingui- form, with broadly rounded apex; lateral margins each with about 20 spines along entire length; apex with 6-7 pairs of closely set long strong spines, central pair longest,
1 From the Greek aduvoedc, brackish.
D.C. 20560
about 1/4 as long as telson. First segment of peduncle of antenna 1 longer than third, with rounded lobe bearing long recurved setae arising from inner distal angle; male lobe slender, about as long as first segment, inner margin thickly set with setae. Scale of antenna 2 narrowly lanceolate, 2-seg- mented, distal segment about 0.4 as long as proximal; distal segment of peduncle pro- duced into spine on outer distal corner. Labrum rounded anteriorly; posterior margin with small central margination; middle 2/3 armed with short setae. Molar of mandible obsolete; incisor curved so that in some views it appears bipartite, with 9 teeth in left mandible, 5 teeth in right; left lacinia mobilis broad, with 6 teeth; right lacinia much smaller, constricted at base, with 5 teeth; spine row of 7-8 spines, with numer- ous setae interspersed among spines; palp well developed. Outer plate of maxilla 1 with 9 spines at apex; inner plate with 2 setae at apex and | on outer margin. Proxi- mal lobe (lobe of second segment) of maxilla 2 with 4 setae on truncate apex; exopod with 4 setae. Thoracic leg 1 (maxil- liped) short and stout. Leg 2 (endopod of 2nd thoracic appendage) slender; segment 6 slightly longer than segment 5; segment 7 ending in nail, posterior margin with 4 robust long barbed setae, anterior margin with about 10 long naked setae. Legs 3-7 slender, subequal; tarsus of 2 segments, first about 4 times as long as second; prehensile distal end formed by long slender dactyl and 5 long setae, 4 inserted at distal end of first and 1 at distal end of second tarsal segment.
EDITORIAL COMMITTEE FOR THIS PAPER:
Dr. WILLIAM D. CLARKE, Marine Sciences Section, General Motors Defense Re- search Laboratories, Goleta, California
SIDNEY S. HERMAN, Assistant Professor of Biology, Lehigh University, Bethlehem,
Pennsylvania
Dr. OLIVE S. TATTERSALL, Pendeen, 66, Sinah Lane, Hayling Island, Hants, England
15
16 Tulane Studies in Zoology Vol. 12
Figures 1-14. Mysidopsis almyra, new species: 1. anterior part of female, lateral; 2. male, dorsal; 3. telson, dorsal; 4. male antenna 1, proximal segments, dorsal; 5. scale of female antenna 2, dorsal; 6. labrum; 7. right mandible, external (ventral) view; 8. right mandible, gnathobasic process, external view; 9. same, internal (dorsal) view; 10. left mandible, gnathobasic process, internal view; 11. same, oblique internal view; 12. maxilla 1; 18. maxilla 1, outer plate; 14. maxilla 2.
No. 1
Leg 8 much shorter than other legs. Male pleopod 1 with lobe bearing 6 setae at base of endopod. Endopod of male pleopod 4 with 2 lobes bearing 1 and 6 setae respec- tively; exopod longer than endopod, with long barbed robust apical spine. Exopod of uropod about twice as long as telson (ex- cluding terminal spines), curved gently out- ward; endopod about 3/4 as long as exopod, armed on ventral surface near medial margin distal to statocyst with a single long spine.
Color. In preserved specimens black chro- matophores are distributed as follows: Dor- sally, 1 pair at base of telson; ventrally 2 pairs on thorax, 1 in midline near posterior margin of pleonites 1-5, 1 on each posterior oostegite near base.
Types. Male holotype, USNM_ 110924, female allotype, USNM 110925, and 8 para- types, from station A. IL 188, 2.4 km off- shore from the mouth of Bayou St. John, Lake Pontchartrain, Louisiana, collected 28 Dec. 1953, by Rezneat M. Darnell. More than 450 specimens collected by Dr. Dar- nell from other stations in Lake Ponschar- train in 1953-54 have also been designated as paratypes.
Occurrence. In addition to the specimens from Lake Pontchartrain, I have identified specimens of M. almyra from St. Andrews Bay, Florida, collected by Thomas L. Hop- kins, and from the north end of Buttonwood Canal, connecting Florida Bay at Flamingo with Coot Bay, in the Cape Sable region of southern Florida, collected by Raymond B. Manning (cf. Tabb and Manning, 1961; Tabb, Dubrow, and Manning, 1962). At all 3 localities the salinity is low, at least sea- sonally. At the Lake Pontchartrain stations from which I have specimens of M. almyra, the salinity varied from 2.0-5.2°/o0, and Darnell (1958) reports a salinity during his study (July 1953 to August 1954), of 1.2-18.6°/o0, with an average of less than 6°/oo and a maximum of less than 9°/o9 for most months. In the St. Andrews Bay sys- tem the salinity ranges from low values in the upper reaches to values only slightly below full ocean salinity in St. Andrews Bay proper, West Pass, and East Pass (Jones and Ichiye, 1960; Ichiye and Jones, 1961). Specimens of Mysidopsis almyra were col- lected by Hopkins at stations $3 and S5 (Hopkins, 1963) in St. Andrew Bay and West Pass respectively, and the salinities at the times of collection were 33.1°/o9 and
New Mysid Crustacean Ly
Figures 15-19. Mysidopsis almyra, new spe- cies: 15. leg 1; 16. leg 2; 17. leg 2, dis- tal segment; 18. leg 3, distal segments, viewed from above; 19. leg 8.
:
EZ
LBA oy 4 |
DAA
e¢
GeoeoC eC? QOEOLO CE LU TL
oe
»
\ || los
Figures 20-24. Mysidopsis almyra, new spe- cies: 20. pleopod 1, male; 21. pleopod 1, male, endopodal lobe; 22. pleopod 4, male; 23. left uropod, ventral; 24. genital appen- dage, male.
=
24
18 Tulane Studies 1n Zoology
27.3-33.7°/oo respectively (Hopkins, in litt.). At the site of collection in Buttonwood Canal the salinity undergoes marked fluctu- ations, varying from less than 18°/99 to more than 40°/o9 (Tabb, Dubrow, and Manning, 1959).
Mysidopsis almyra is very abundant in Lake Pontchartrain. Quoting Darnell (1961), the zooplankton “is dominated by the cala- noid copepod (Acartia tonsa) and to a lesser extent by adult schizopods (Myszdopszs sp.) and larval penaeid shrimp.” M. almyra is an important item in the diet of a number of Lake Pontchartrain fishes (Darnell, 1958). Both young and adult Anchoa mitchilli dta- phana feed on this mysid; in other fishes (Ictalurus furcatus, Cynoscion arenarius, C. nebulosus, Micropogon undulatus, Sciaenops ocellatus) only the young specimens feed on Mysidopsis, the older individuals turning to larger prey. Finally, the young of some fishes (Menidia beryllina and Baitrdiella chrysura) prey mostly on copepods; as these fishes grow older, they come to depend more on mysids.
Remarks. Only 3 species of Mysidopsts, M. angusta G. O. Sars, M. didelphys Nor- man, and M. indica W. Tattersall, have a single spine on the uropodal endopod near the statocyst. These species differ from M. almyra in having very short distal segments of the antennal scales and 3-segmented tarsi on thoracic legs 3-8, and their telsons are quite different. Only 1 species of Mystdop- sis, M, bigelowi W. Tattersall, has been re- ported from the Gulf of Mexico: Tattersall (1951) reports it from Calcasieu Pass, Lou- isiana (I have examined these specimens and confirm his identification); Clarke (1956) records it from 10 miles off Bara- taria Light, Louisiana, and the U. S. Na- tional Museum has a single specimen col- lected by the M/V Silver Bay off southern Florida (26°20'N, 83°02’W). M. bigelowi is easily distinguished from M. almyra by its smaller eye, unsegmented antennal scale, the very robust thoracic leg 2, the presence of
Vole,
5 spines near the statocyst, and the armature of the telson.
REFERENCES CITED
BOWMAN, THOMAS E. 1957. A new species of Mysidopsis (Crustacea: Mysidacea) from the southeastern coast of the United States. Proc. U. S. Nat. Mus. 107(3378) : 1-7.
CLARKE, WILLIAM D. 1956. A further de- scription of Promysis atlantica Tatter- sall (Crustacea, Mysidacea). American Mus. Novitates 1755: 1-5.
DARNELL, REZNEAT M. 1958. Food habits of
fishes and larger invertebrates of Lake Pontchartrain, Louisiana, an estuarine community. Publ. Inst. Mar. Sci. Univ. Texas 5: 353-416. AS an IER 1961. Trophic spectrum of an estuarine community, based on studies of Lake Pontchartrain, Louisiana. Ecology 42(3): 553-568.
HOPKINS, THOMAS L. 1963. The variation in the catch of plankton nets in a system of estuaries. J. Mar. Res. 21(1): 39-47.
ICHIYE, TAKASHI and MEREDITH L. JONES 1961. On the hydrography of the St. Andrew Bay System, Florida. Limnol. Oceanogr. 6(3) : 302-311.
JONES, MEREDITH and TAKASHI ICHIYE 1960. Hydrographic data of the St. Andrews Bay system, Florida. Florida State Univ. Oceanogr. Inst. Contr. 148: 1-56 (mimeo- graphed).
TABB, DURBIN C., DAvip C. DUBROW, and RAYMOND B. MANNING 1959. Hydro- graphic data from the inshore bays and estuaries of Everglades National Park,
_ Florida, 1957-1959. Mar. Lab. Univ. Mi- ami Rept. 59-5: 1-26 (Mimeographed).
PA teen eries eRe oem The ecology of northern Florida Bay and adjacent estu- aries. Florida State Board Conserv. Tech. Ser. 39: 1-79.
TABB, DURBIN C. and RAYMOND B. MANNING 1961. A checklist of the flora and fauna of northern Florida Bay and adjacent brackish waters of the Florida mainland collected during the period July, 1957 through September, 1960. Bull. Mar. Sci. Gulf and Caribbean 11(4): 552-649.
TATTERSALL, WALTER M. 1926. Crustaceans of the orders Euphausiacea and Mysida- cea from the western Atlantic. Proc. U. S. Nat. Mus. 69(2634): 1-28, pls. 1-2.
So ee 1951, VAtSreviewsotethe Mysidacea of the United States National Museum. Bull. U. S. Nat. Mus. 201: 1- 292.
August 21, 1964
TULANE STUDIES IN ZOOLOGY
Volume 12, Number 2
February 23, 1965
AGE DETERMINATION OF THE COTTON RAT (SIGMODON HISPIDUS)*
ROBERT K. CHIPMAN, Department of Zoology, University of Vermont,
Burlington, Vermont
CONTENTS
BERNE SHRUG Ss ae. ee eee 19 II. INTRODUCTION. 20 NBIVIACRER TAT. -AINID IME SE @D Si ee eee 21 PWemmlbaBOLACOLV SUUGY =. 228s 8 tA a ate eee ee NE ee, ED
B. Field study 22 Pere MLA OOCy MCAS UT I CICS ea es ee 22 vemise aera dM OltS ae a See 2 eS SO ee ee serenely rm eke IZA
COMBE LO UGE OI Pea ea GON he = a octet is IE a ng Bre om ta sey SD
ILD) Fang ER es Gil eterna a nee ee eels Rk Paes nas Oe BS rj oe sees. eae egy Wi,
AS CIC CC iaiere naket 248 ne) oan hae i 28
MMM INS VC ele en oh ee ee ea Be, ein Ns ee ee eee ee eae SN
MGB FL) CLES EU lee Marsters BS ne ON a AM I in ded on eee BY emPESUSSION ANDi CONGHU SIONS 25: 22 eee ot Se ee OD WAP NGRINO WALLED GENIE IN GUS etn soe ie ee A ee ee 37 WIRRIMPIRERIPNGES @IVGED 2-2 ee OF
I. ABSTRACT
A study based on 316 known-age specimens of the cotton rat, Sigmodon hispidus hispidus, from southeastern Louisiana consisted of a laboratory and a field study. The categories of mor- phological characters examined were: body measurements; pelage and molt- ing; reproductive activity; teeth; skel-
changes of these characters were stud- ied through twelve months of age. The laboratory study showed that body length, molting stage, epiphyseal fu- sion, skull measurements, and dry lens weight combine to give a high de- gree of success for age-determination through six months of age.
The field study consisted of releas-
ing 96 known-age cotton rats and suc- cessive periods of retrapping. The re- trapping data support the conclusions of the laboratory study. Weight as an age-determining character is discussed and evaluated from the field data of this and other studies.
etal growth; and lens weight. The
* This paper is based on a dissertation submitted in partial fulfillment of the re- quirements for the Ph.D. degree in Zoology at Tulane University, New Orleans, Lou- isiana, 1963.
EDITORIAL COMMITTEE FOR THIS PAPER:
KYLE R. BARBEHENN, Lecturer on Biology, Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania
JAMES N. LAYNE, Associate Professor of Zoology, Department of Conservation, Cor- nell University, Ithaca, New York
NorMAN C. NEGUS, Associate Professor of Zoology, Department of Zoology, Tulane University, New Orleans, Louisiana
19
20 Tulane Studies n Zoology
Il. INTRODUCTION
The need for reliable criteria for esti- mating the age of wild animals has been noted by many researchers and has been re- viewed by Alexander (1958). Support for the study of age-indicating techniques .has been devoted primarily to the larger game mammals due to sporting interests. Even when studies have been undertaken on smaller mammals, the emphasis is still placed on those species that are of interest either for hunting or for their commercial fur value. With the recent interest in the study of populations of small rodents and particu- larly the occasional dramatic fluctuations in their numbers, there is an increasing need for accurate methods for determining age classes.
The degree of accuracy necessary for esti- mating the age of any given animal will de- pend on the species itself. For example, if the species does not breed until it is several years old, the estimation of age in units of time of less than one year will have little practical value. If, however, the species breeds at the end of its first year, then esti- mation of age to one year or even less would be desirable to distinguish between young of the year and adults for the next breeding season. In the case of small rodents more precise estimation of age is necessary as many of the young will become reproduc- tively active during the breeding season in which they were born. Three or more gen- erations in a breeding season of a small rodent are not uncommon and may be the rule especially if the species breeds through- out the year. Occasional trapping in the animal’s natural habitat will not solve the problem of age determination as the age of the captured animals so collected will be un- known, and only rough approximations of age classes can be formulated. A solution can only be found by first studying the de- velopment of various morphological char- acters on animals whose individual ages are known. Ideally, field studies should be undertaken concurrently on known-age ani- mals to verify or adjust the laboratory de- rived data.
Thus, the purpose of this study was to determine useful age-determination char- acteristics from laboratory-raised cotton rats (Sigmodon hispidus) and to field-test the application of those techniques. Hopefully,
Vol. 12
the techniques that are successful for deter- mining the age of the cotton rat will aid other researchers in age determination of small rodents.
Studies on growth of the cotton rat are limited largely to weight and measurement data. Svihla (1929) described cotton rats at birth, their early growth, and their ability to feed at about ten days of age. Meyer and Marsh (1943) noted that cotton rats be- come sexually mature at six to seven weeks. In the most elaborate study of growth of the cotton rat Meyer and Meyer (1944) pre- sented considerable data on the growth of the young and additional data on growth through 15 months. Body weights are given in units of 5O days of age, but do not give good indication of being reliable criteria for aging of the animal. Furthermore, the sam- ple size is limited to three to six animals. Information was presented that the rate of growth is influenced by the age of weaning. Data were also given for growth of various endocrine glands, but the areas of overlap from one age group to another were too ex- tensive for estimating the age. No data were presented on body measurements, the growth of bones, the progression of molts, the de- velopment of the baculum, or the several other categories investigated in this study.
McIntire, Schweigert, and Elvehjem (1944) studied the increase in weight of the cotton rat to six weeks of age. The authors noted that both sexes grow at the same rate al- though the female is somewhat smaller than the male at any given age. Odum (1955) indicated breeding begins at a weight of 62- 87 grams and at an age of 40-50 days. Indi- vidual size of the animals varied with the density of the population, animals being larger at lower than at higher densities. Data on weight were given for a limited number of known-age individuals. Odum also noted that very few individuals survived six months of live trapping, which may give some indi- cation of longevity under field conditions.
Sealander and Walker (1955) suggested that size is no indication of reproductive capabilities. The population studied by these authors was aged by the use of the laboratory weight data of Meyer and Meyer (1944). Age classes based on body measurements were thought to be of little value as these classes had little relationship to weight. Keys (1958) followed the rate of embryonic and early postnatal development. He noted that
No. 2
the cotton rat is quite precocious at birth and develops at a remarkably rapid rate. His study was not carried beyond 15 days of age.
Ill. MATERIAL AND METHODS A. Laboratory Study
A breeding colony of wild cotton rats from southern Louisiana was organized in the spring and summer of 1960. Some of the young born of the wild cotton rats were also used as breeders in the laboratory. Breeding pairs were housed in large cages. Large fruit juice cans and cotton batting were found to make satisfactory nesting sites. Little fighting occurred after the first few days of pairing.
The females usually bore young two to four months after pairing. The male ignored the newborn young, and was left continually in the cage to take advantage of the post- partum estrus. The breeding females were palpated every two weeks to determine preg- nancies. Once a litter was expected the cage was checked daily. At parturition the female would bar the male from the nest can; he then made a nest elsewhere in the cage. This action normally served to establish the date of birth. Also, as the eyes of the young are closed at birth but open the next day, a quick check of the newborn young would verify the date of birth.
The laboratory-born young that were used as breeders were usually paired when weaned (three weeks). At this age males and females were amicable. If pairing was delayed until after six weeks, some fighting resulted. In a few instances when the newborn young were a week to ten days old, the female, whether wild or laboratory raised, would viciously attack the male, chewing the hide from the back of the head to the sacral region. The pair was then separated and no further attempt was made to breed the female, although invariably a litter was born about two weeks after the separation.
The cotton rats were fed a diet of Wayne Lablox exclusively. Water was available ad libitum. The breeders were occasionally fed fresh greens in the earlier stages of this study. Most of the laboratory-bred cotton rats were secretive during the day, or at night when any activity was taking place in the laboratory. Although I made constant efforts to handle and tame the cotton rats, especially the young, the attempt proved use-
Age Determination of Cotton Rat Ail
less. The tamest animals in the colony were wild-born, adult breeders. Generally the ani- mals were removed from their cages by trapping them in their nest can or by chas- ing them into a Sherman live trap. The animals were then etherized for examination. Once subdued the animals would not bite but would still try to escape.
Meyer and Meyer (1944) showed that cotton rats weaned at 10 days of age did not gain weight as rapidly as those weaned at 20 or 30 days, the difference between the latter two ages being slight. Rabasa (1952) showed growth rates in albino rats to vary depending on the number of individuals per cage. For these reasons all cotton rats were weaned at the same age (21 days) and, with the exception of the few used for breeding purposes, were caged individually. Cages contained between 110 and 120 square inches of floor space and were supplied with coarse sawdust or shavings, a nest can of suitable size, and some cotton for nesting material. The nesting material was exten- sively used during winter, but was generally ignored during summer, although the tem- perature in the air-conditioned animal room was seldom lower than 65° F or higher than 75° F. I attempted to limit the photoperiod to that available as sunlight. Occasionally the animals received additional light when night work was necessary. The variations of light and temperature were kept to a mini- mum whenever possible, but may have af- fected some of the laboratory data, as will be discussed below.
The study was based on 12 samples. The first sample was made up of one-month-old animals. Successive samples were one month older than previous samples through 12 months of age. Each sample was derived from 3 to 5 separate litters and was planned to be composed of 5 males and 5 females. Cotton rats were assigned at the time of weaning to the older incomplete month-age samples. The first few litters were composed predominantly of males, causing the 12- month sample to have an undesirably high number of this sex. With the exception of the conditions described above, the animals were assigned to a sample at random. A few individuals died or were accidently killed prior to attaining their desired age, causing some deviation from this plan. Adjustments were made where possible.
Three wild-caught individuals were kept
22 Tulane Studies tn Zoology Vol. 12 TABLE 1. Distribution of individuals forming the laboratory study. Age of Sample (Months)
1 Zi 3 5 6 i 8 9 10 1 2, 18
Males 5 5 6 5 5 5 5 6 3 3 4 9 2
Females 6 5 6 5 4 5 8 1 W 6 5 A 1
Total 11 10 Ak 10 9 10 13 7 10 9 9 ial 3 Number of litters
represented 4 5 5 5 a 4 5 3 3 3 4 4 ~
in captivity as breeders for 16 months. These were judged to be two or more months old at capture and are thus considered to have been 18 months or older when sacrificed. The data from these individuals were incor- porated where possible. The composition of each month-age sample as to number, sexes, etc., is given in Table 1. The animals used in this study came from litters ranging from 5 to 10 young. No significant difference existed in weight or body measurements be- tween the different sized litters.
All cotton rats were etherized and exam- ined every two to four weeks for molting and reproductive condition. Individuals were sacrificed with ether when they had reached the desired age in months and on the same day of the month as their date of birth. The animal was then weighed, and the standard body measurements {total, tail, hind foot (not including nail), and ear (measured from the notch) lengths} were taken. The cotton rat was then skinned, the pelt being pinned out flat for drying. Both eyes were removed, placed in formalin, and the lenses later removed. The lenses were dried and weighed on a Mettler analytical balance to 0.1 mg.
The skull was severed, dried, and cleaned by dermestid beetles. The left forelimb and scapula were removed, fixed in 40% 1s0- propyl alcohol, and later macerated and stained to study the epiphyseal areas. The right forelimb was similarly removed and preserved in formalin together with the tail. Both structures were later X-rayed for epiphyseal fusion. The entire penis was re- moved, macerated, and the baculum stained. Other reproductive structures were inspected, and pertinent notes taken. The remaining portion of the carcass was preserved in formalin.
B. Field Study
Growth data on laboratory-raised individ- uals of a wild species would not be expected
to be the same as on animals in their nat- ural habitat. Many differences exist be- tween the laboratory and the natural habitat, such as food and climatic factors. Moreover, the cage environment may produce condi- tions that affect the normal growth of the animal. The limitations of activity, the lack of extreme environmental variation, and the change in social patterns are difficult to evaluate. Thus I attempted to obtain growth data on known-age cotton rats in their nat- ural habitat by releasing and retrapping young cotton rats born in the laboratory (in- dividually marked by toe-clip). The re- trapped individuals were examined and re- leased, hopefully to be retrapped a second time. IV. RESULTS A. General Body Measurements
The body length measurement was ob- tained by subtracting the tail length from the total length. I consider this computed measurement more reliable than either of the other two measurements, as portions of the tail are frequently lost.
The data for weight (Fig. 1) and for body
250
200
150
Weight in Grams
100
50
2
I 525342 S266. 7 8 See Oma 18
Age in Months
Figure 1. Body weight when sacrificed of known-age cotton rats by sex. The vertical line indicates the range and the horizontal line the mean of the sample. The left line of each pair is the data for males, the right line the data for females.
No. 2
length (Fig. 2) are presented by sex. The difference between the sexes for these char- acters was considered significant (P==0.02). The sexual dimorphism of hind foot and ear length (Fig. 3) is not considered significant (P=0.3), and the data are combined for both sexes.
Length in Millimeters
fea) 34s 67 a9" 10) iM i2 18 Age in Months
Figure 2. Body length when sacrificed of
known-age cotton rats by sex. (See Figure
1 for description).
Height and Lenath in Millimeters
ices 4.75) 56) 7 8 9 TOMI le 18
Age in Months
Figure 3. Ear height and hind foot length when sacrificed of known-age cotton rats. Data are for both sexes. Upper series of data are for hind foot length; lower series of data are for ear height. The vertical line represents the range and the horizon- tal line the mean of the sample.
While of limited value for age determina- tion, these data should be considered in de- tail as these measurements are classical mam- malian measurements. The measurements differentiate satisfactorily between one- and two-month-old animals, and distinguish these two age groups from older specimens. The age groups are best separated on the basis of body length and, to a lesser extent, by hind foot and ear lengths. Weight appears
Age Determination of Cotton Rat 23
to be least related to age and is the most variable measurement.
The usefulness of any character for age determination depends in part on knowing and evaluating its variability. One possible variable might be the day length during the first few months of the cotton rat’s life, since this was not controlled. The body length of nine males and five females born between September 8th and 12th are compared with 11 males and 12 females born between Janu- ary 11th and 14th (Fig. 4). The first group
180 5 % 160 E = £ 140 = > 5 120 5 =f VES —= 100 a7 Females== == = = w
3 6 9 l2 ifs) 18 2l 24 Age in Weeks
Figure 4. Variation in mean growth rates of known-age cotton rats, depending on the time of the year in which the animals were born.
was exposed therefore to a decreasing day length for three months and then to an in- creas ng photoperiod, the second group being exposed only to an increasing day length. The January group was consistently larger at each age in body length than the Septem- ber group. While Figure 4 shows only the means for the sample, the ranges of the measurement showed little overlap. At three weeks of age the means differ by 10 mm, while at nine weeks the differences are 14 mm for females and 19 mm for males. At these two points there are no areas of over- lap of the range. For the males this differ- ence in body length is maintained until twenty-three weeks of age, the limit of the data. For the females the means appear to be approaching each other at this age.
Body length is the most reliable measure- ment for age determination (Fig. 2). How- ever, the seasonal variation, whatever its basis, could handicap the data. Perhaps sepa- rate growth curves could be used during dif- ferent seasons, but this seems a questionable procedure.
A second source of variation might be
24 Tulane Studies in Zoology
genetic, i.e., would growth curves determined by animals from one area be applicable to animals from another area? The only other study of laboratory cotton rats is that of Meyer and Meyer (1944). The stock for their colony came from Baton Rouge, Lou- isiana, 80 miles from the locality of my stock, and belong to the same subspecies (S. h. hispidus), The only comparable data presented by these authors are body weights, and when their growth curves are plotted with mine the curves are virtually contigu- ous. This fact does not really answer the question posed as to genetic variability, al- though the similarity of the two growth curves suggests the data of my study might be used within the range of this subspecies safely.
A third question raised by the data is the apparent decrease in means and ranges of measurements at 8 or 9 months in Figures 1, 2, and 3. Each age sample comprises only the measurements of the sacrificed animals. Thus at 8 or 9 months there is no decrease but only the data from smaller animals. The reason for these smaller animals is not at all clear. The best suggestion seems to be the season in which the specific individuals were born. Those animals forming the eight- and nine-month samples were born in No- vember and December, while those forming the younger age samples were born in Janu- ary through March. Photoperiod can be sug- gested as the cause, but the mechanism is only conjecture.
Undoubtedly other factors will affect body weight and measurements. Sealander and Walker (1955) and Dunaway and Kaye (1964) have shown the mean body weights to decline during winter when depot body fat is being rapidly consumed and recruit- ment of the population is low.
B. Pelage and Molts
The results presented in this section are based primarily on observations of the dried pelt, with data of live animals being used as a check and/or elaboration.
The pelage of cotton rats displays a re- markable degree of uniformity throughout the animal’s life. All the pelts were viewed at One time, but no real variations in color, shade, or texture could be observed except for very young cotton rats (one to two weeks old) in which the pelage was notably softer and composed of shorter hairs.
Vol. 12
The actual molting patterns or progres- sions are diagramed in Figure 5. Several specific molts can be demonstrated onto- genetically. The newborn cotton rat is com- pletely furred with short hairs somewhat darker than the adult. The juvenile pelage becomes complete within one week of age at which time the young cotton rat begins the very rapid molt to the subadult pelage. This molt begins in the ventral thoracic region. The three-week-old animal is molt- ing laterally. At four weeks of age the ani- mal is molting dorsally only. The new pel- age is complete between five and six weeks of age, and the animal is now a subadult (i.e, may become reproductively active but physically smaller than the adult body size). This molt is extremely constant both in pat- tern and duration.
The next molt is termed the adult molt, since at its completion the cotton rat has reached adult size and the growth rate de- creases abruptly. This molt usually begins at five to six weeks of age, often while the previously described molt is still present dorsally particularly on the top of the head. The progression of this adult molt is the same as for the subadult molt except for duration. The first molt requires about one month for completion while the adult molt requires two and one-half to three months. As a practical point, these two molts can be distinguished by: (1) the presence of juvenile pelage dorsally in the subadult molt; (2) the adult molt occurring as a narrow lateral band while the subadubt molt being present over one-half of the body surface at once; (3) the small size of the animal dur- ing the subadult molt.
As early as five months but usually around six months, the cotton rats molt again. This molt, very irregular both in duration and extent, has been termed a patch molt. My observations indicate that this molt follows the general pattern described for the pre- vious molts and differs in that only small disconnected areas are molting at any one time. Both the duration and precise pro- gression of this molt are difficult to follow, especially since the animal will frequently stop molting only to start again where it stopped or commence a new molt, or both.
Further adult molts occur with increasing irregularity both in area and duration. Molt- ing is most easily observed when present laterally, particularly around the front limbs
No. 2
and on the cheeks. The molting areas are small and scattered, and become even more so as the molt progresses dorsally. I have presumed the typical ventral-to-dorsal pro- gression occurs, but definite observations are insufficient for a positive description due to the limited number of animals raised to the older age samples. The later adult molts ap- pear strongly influenced by photoperiod and, in the case of a few known-age females used as breeders, by reproduction as well.
The adult molts need more critical study than could be undertaken. However, if a normal longevity of six to eight months is postulated, then the molting pattern, if closely examined, could be helpful for esti- mating the age of the cotton rat. If the specimen shows no molting, then the ani- mal is either in complete subadult pelage (about six weeks old) or in complete adult pelage (about five months old). Body length or weight could be used to distinguish these two ages. The use of the molting pattern for age determination of cotton rats does not consider environmental variations.
Photoperiod will potentially influence the use of molting as an aging device, although
nose
lower jaw
\ina eye
front limb
hind limb
3 Weeks
Age Determination of Cotton Rat 25
the major variation seems to occur after the subadult-to-adult molt has been completed. Mohn (1958) described the development of “growth waves” (1e., ontogenic molts) for the black rat (Rattus norvegicus) which are virtually identical to my observations in age at Onset, progression, and duration. The similarity of these observations as well as those by other authors suggests that the first few molts (to the adult pelage) are more influenced by ontogeny than other fac- tors. Mohn also comments that the later (adult? ) molts are considerably more vari- able and the frequency and rate are retarded by both pregnancy and lactation.
A microscopic examination of individual hairs and groups of hairs was undertaken. The hairs of one-month-old animals were distinctly shorter and were a mixture of the shorter juvenile hairs and the incompletely grown subadult hairs. Otherwise microscopic examination of the hair was of no value for age determination.
C. Reproduction
The condition of the external reproductive structures was included in the periodic ex-
6 Weeks 2 Months
5 Months 7 Months
patterns of known-age cotton rats viewed from the skin side of the
3 Months 4 Months Figure 5. Molt ‘ pelt. Darkened areas indicate areas of active molting.
26 Tulane Studies in Zoology
amination of the live cotton rats. For males the position of the testes (scrotal or ab- dominal) was determined. The pigmenta- tion and relative size of the teat and the con- dition of the vaginal orifice (perforate or imperforate ) were recorded for each female. Additional data were derived from an ex- amination of the birth dates of litters from known-age parents.
The youngest age at which a rat gave birth was 65 days, having been impregnated by a litter mate. Subtracting a gestation period of 27 days (as determined by Meyer and Meyer, 1944) gives an age at conception of 38 days. This particular individual was the only spring-born (February) female that was used for breeding purposes. All other data on age at first litter are from animals born during September and October. For these individuals the youngest age at which a female gave birth was 84 days, with con- ception thus occurring at 57 days. The age at conception of the first litter for other females ranged from 70-100 days, with the older age being more common. Meyer and Meyer noted one female being impregnated at 40 days of age and several others by 50 days of age. These authors also noted the first estrus to occur at a younger age during the period January-through-June than dur- ing the period September-through-December.
The condition of pregnancy is of value for age determination only to the extent that the investigator can determine a probable mini- mal age. Furthermore, nonimpregnated fe- males need not necessarily be less than that minimal age. Additionally, Odum (1955) and Haines (1961) have shown that the cot- ton rat has seasonal reproductive peaks and occasional periods of anestrus, especially during the winter. Presumably photoperiod affects the age at onset of reproductive ma- turity although other factors undoubtedly exist. Thus pregnancy is at best a limited tool for age determination.
The earliest age at which a_ perforate vaginal orifice was noticed was six wecks. By three months all females had shown this condition at least once. When sacrificed, one two-month-old female had a distended, fluid- Mee uterus, a condition described by Clark
1936) as occurring during proestrus and estrus. An active estrus, as determined by a perforate vaginal orifice or an examination of the uterus, might be more helpful for age determination than pregnancy as it occurs
Vol. 12
independent of male cotton rats. However, the condition is still influenced by season and, like pregnancy, is of value only for es- tablishing minimal age.
Size and extent of the pigmentation of the teat were constant for females two months or older, except for pregnant and nursing individuals. One-month-old females showed no pigmentation except for the one female mentioned above that bred at 38 days of age. By two months all females showed some pigmentation, and by three months all possessed a dark-brown pigmentation of the teat. A week or ten days prior to the birth of a litter the teats become enlarged and change from dark-brown to black pigmen- tataion. The dark-brown color returns after weaning if the female is not pregnant. The size and degree of pigmentation of the teat suggest an expression of sexual maturity and activity rather than of age.
Sexual maturity in males can be deter- mined by the presence of viable sperm in the epididymis. No sperm were seen in smears of the epididymis of one month and six-week-old males. The testes normally de- scend and remain in the scrotal sac at two weeks to one month for laboratory-raised young. Of the five two-month-old males, only two contained sperm in the smeared epididymis. Viable sperm were present in all males three months of age or older. The two earliest pregnancies reported above (conception at 38 days) were by males of the same age as the females. Haines (1961) has shown that male cotton rats vary as much as females seasonally, although I did not notice this. Whatever the variations and their causes, reproductive maturity in males is only indicative of a minimal age of per- haps two months and is thus of very limited value for age determination.
The baculum and its digital processes were studied after maceration and staining. Mac- eration was considerably hastened by pre- serving the penis in 40% isopropyl alcohol. Stained specimens were stored in glycerine containing 0.5% phenol to inhibit mold. All bacula were measured with dial calipers. The total length and the height and width of the base were carefully examined, and char- acter indices were attempted. One-month- old animals were distinct, but all older age groups encompassed the same measurements. The staining of the bacula showed a high
No. 2
degree of uniformity, variations being prob- ably due to staining technique.
Forty-two bacula had digital processes that were satisfactory for study. Of these, 18 were less than seven months of age and showed no deposition of stain in the processes and may thus be assumed to exhibit no ossifica- tion. Seven-month-old specimens show a small amount of stain in the tip of the medial process, which increases in extent with age. The lateral processes begin to show staining at nine months, also increas- ing with age. The extent of the staining is nearly complete at 12 months, showing very little increase at 18 months. The progression of the stained areas is illustrated in Figure 6.
yd “RNS
Nd “AN
And “ARE An 4
Figure 6. Digital processes from bacula of known-age cotton rats. Number at each group of three indicates the age. The first figure on the left is a ventral view of the median cartilage; the middle figure is a lateral view of the median cartilage; the figure on the right is a ventro-lateral view of a lateral cartilage.
The value for age determination of the staining of the digital processes is limited to male animals over six months of age. In all probability this would be a very small portion of the population. If sufficient numbers of males with ossifying digital processes could be collected, some evaluation of the age composition of the older individ- uals could be made, especially if one pre-
Age Determination of Cotton Rat 27
sumes the same age distribution for the females. D Leeth
Twelve measurements were made of vari- ous individual teeth and tooth rows. The re- sults were effective only to separate one- month-old cotton rats from all older age groups which remained indistinct from each other.
Three subjective tooth characters became evident when measuring the skulls. When viewed laterally, the occlusal surface of the lower molariform teeth appears as a straight line for the younger animals. For the older individuals this view becomes more concave, presumably due to the grinding of the two tooth rows on each other (Fig. 7). Subjec- tive categories with numerical values were applied in an attempt to evaluate this uneven wearing. The technique did not prove suc- cessful and was particularly unworkable for very old animals.
The second character was the differential wearing of the first lower molar, the pos- terior two thirds being ground away more rapidly leaving a short prominence or spike on the anterior third (Fig. 7,C and D). The prominence was categorized numerically but the results were similarly unproductive es- pecially for very old individuals which often lacked the prominence.
The third character was the reentrant angle or groove on the lateral crown surface of the molar teeth. As the tooth is worn away, the groove decreases in length and be- comes more exposed. Since the size is too small to measure, I attempted to evaluate the length of the groove as the ratio (ex- pressed as per cent) of this length to the exposed crown height. This evaluation was only made on the first and second molars as the third is partially concealed by the base of the coronoid process. Again the char- acterization was not significant. The de- creased length of the groove is evident in Figure 7.
At the age of one month only eight molars are visible in the cotton rat. The third molar (both mandibular and maxillary) has not yet broken the skin although the tooth is not covered with bone. By two months, the tooth has completely erupted and has attained ap- proximately the same height as the first and second molars.
The occlusal surface is quite constant throughout the life of the cotton rat. The
28 Tulane Studies n Zoology
Sigg:
Figure 7. Lower jaws of known-age cot- ton rats. A—1 month, B—3 months, C— 6 months, D—9 months.
changes were more difficult to evaluate than the three subjective categories listed above and thus were of even less value for age determination.
E. Skeleton
Skulls of a male and a female of each age group were randomly selected for a pre- liminary study of characters that might be useful for age determination, measurements
Vol. 12
being made with dial calipers. Over thirty measurements were investigated. Measure- ments of: 1) nasal length; 2) greatest zygomatic breadth; and 3) greatest width of the lambdoidal crest seem to be related to age, and were made on all skulls, as was the condylobasilar length. The data from the four measurements are summarized in Figures 8-11.
For the condylobasilar length (Fig. 8) the data are presented separately for each sex, the males at each age having significantly longer skulls than the females (P==0.05 at one month of age; P==0.02 at all older ages). For the other three measurements ( Figs. 9-11) the differences between the sexes were small although the males were uniformly larger. P values were as low as 0.1 in a few instances but for the most part were 0.3 or greater. The data do not warrant being
Length in Millimeters
3.4 5 6 7 8) 9) slomiiml2 18 Age in Months
|
Figure 8. Condylobasilar length of known- age cotton rats by sex. (See Figure 1 for description. )
J] hl |
Age in Months
Figure 9. Nasal length of known-age cot- ton rats. (See Figure 3 for description.)
Oo
Rh
june
Breadth in M limeters
Ad
ee sses 5516 676 69) 108 I) Ie 8 Age in Months Figure 10. Lambcidal breadth of known- age cotton rats. (See Figure 3 for descrip- tion.)
Breadth in Millimeters
i 2 Slee Gem eG Gite ee i Age in Months Figure 11. Zygomatic breadth of known-
age cotton rats. The thinner, vertical line on the left of each symbol represents the range of the data. The heavier, vertical line on the right of each pair represents two standard deviations on either side of the mean, which is indicated by the horizon- tal line.
separated by sex especially considering the small sample size.
The measurement of the most apparent value for age determination is the zygomatic breadth (Fig. 11). For this measurement the standard deviation was computed and added to the figure as two standard devi- ations on either side of the mean. This procedure was used to determine the validity of the sample as the two standard deviations would thus represent ninety-five per cent of the population and provide more comparison than the actual ranges.
By inspection one-month-old individuals
Age Determination of Cotton Rat 29
are distinct from all other groups. The two- month-old individuals are nearly distinct. A line has been added to the figure at 18.7 mm to separate the two-month-old individ- uals from older specimens. The overlap of the data is in the standard deviation only, the ranges being distinct. Three- and four- month animals together form a group which is largely separable from the rest of the animals in this study. A second line has been added at 19.8 mm _ which, although arbitrary, separates most of the three- and four-month specimens from most older in- dividuals.
Thus, four age groups can be identified: 1) one-month-old individuals; 2) two- month-old individuals; 3) three- and four- month-old individuals; and 4) individuals five months or older. These categories have virtually no overlapping of the ranges. The sample size is undesirably small, perhaps accounting for a large standard deviation.
Alexander (1960) has shown that there is approximately a 1.5% decrease in the zygomatic measurement of the muskrat as the skull dries. This shrinkage in cotton rats would amount to 0.3 mm of a zygomatic breadth of 20 mm. Since all skulls were cleaned and measured at the same time, the shrinkage should be uniform and the data still valid. Presumably standard cleaning and measuring techniques should be used when making this measurement on a population sample. Character indices also were com- puted by various combinations of the four measurements, but the applicability of the data was not increased.
Older animals exhibit a general increase in the development of the ridges or crests of the skull. The ridges appear to attain most of their development by three or four months, although the skull still appears to become more massive throughout the age groups. However, with the exception of the breadth of the skull at the lambdoidal ridge, all measurements to evaluate this increased size were unsuccessful. Weighing the skulls only served to distinguish one-month-old in- dividuals as a group. Furthermore, when guessing the age of an individual skull by examination of the development of its ridges and its weight, I was successful only with one- and two-month-old individuals. Thus, while subjectively evident, the ridges defy objective measurements and are concluded to be of little value for age determination.
30 Tulane Studies in Zoology
The mandibular weight permitted the identification of both one- and two-month- old animals as groups distinct from the rest of the specimens. The limited value of this measurement does not justify the time spent in the careful cleaning of the mandible be- fore weighing.
The forelimb was studied extensively for areas of epiphyseal fusion that would be of value for age determination. The results described below are a composite of both the maceration and X-ray data, the former being the more easily studied. At one month the distal epiphyses of the metacarpals are distinguished from the diaphyses by a non- staining band of cartilage, which by two months is reduced to a deeper staining suture line. This line becomes indistinct at three months and is absent at four months of age.
The sesamoid bones of the metacarpal- phalanx joint first become apparent by stain- ing at three months of age, but are distinct from the two bones of the digit. At four months the sesamoids are beginning to fuse with the metacarpals, which process is com- pleted at five months of age.
A second series of sesamoids can be seen at four months, at the distal end of the proximal phalanx. Like the first series these bones are fused to the proximal phalanx two months later at an age of six months.
The distal epiphyses of the radius and ulna at one month are distinct and separated from the diaphyses by a clear nonstaining band of cartilage. For animals two months of age the epiphyses are separated only by a line lacking in stain. The epiphyseal suture is about one-half ossified at three months. The process is virtually completed at four months although a suture line is visible in all older specimens and shows very little change. Green (1949) also has noted the persistence of this suture line to older ages in the Norway rat.
The proximal epiphysis of the ulna is very similar to the distal epiphyses of the radius and ulna, clearly distinct at one month and largely ossified to the diaphysis at four months of age. A suture line is similarly present in all older specimens.
The acromion process of the scapula shows no ossification at one month of age and only a small distal area of stain deposition at two months. The amount of ossification gradually increases so that the process 1s
Violet
largely if not completely ossified at five months. A suture line is still visible for a few months, but is absent in all specimens nine months or older.
The suprascapular cartilage is also un- stained at one month of age. At two months a small area of staining appears at the corner of the glenoid and vertebral borders of the scapula. By three months the suprascapular cartilage is ossified about one half its length, but a narrow stain-free area separates the ossifying cartilage from the scapula. At five months of age the cartilage is largely oss1- fied, and only at this time does the supra- scapular cartilage begin to fuse to the scap- ula. This later process continues slowly and is not complete even in the twelve-month animals.
The ossification processes are not all com- plete at six months, but at this age the changes are very slow and irregular. These later stages of ossification and fusion are of very limited value for age determination and are not discussed. All the described areas of ossification are summarized in Figure 8. Other epiphyseal areas exist in the forelimb, but these are either difficult to distinguish, such as the epiphyseal areas of the humerus, or proceed too rapidly to be diagnostic, such as is seen in the epiphyses of the phalanges.
The tail also was X-rayed to study the degree of ossification and fusion of the intervertebral discs. This procedure was in- vestigated as the tail can be X-rayed easily on a live, anesthetized animal where an ex- amination without injury is highly desirable.
For the younger animals the caudal inter- vertebral discs are largely unossified to the centra of the vertebrae. Those that are nearest the pelvis ossify first. The degree of ossification increases with increasing age of the specimen, although it is never complete. Even in the twelve-month-old specimens the last few (three to six) discs remain quite distinct. The major difficulty in evaluating the data is deciding which discs have begun to show ossification in order to produce numerical or even reasonably objective data. No satisfactory method was found. The problem was compounded due to the X-ray film used and its inability to produce a suf- ficiently sharp outline of the structure.
The use of epiphyseal fusion gives promise as an aging device. While the best data are derived from the examination of macerated material, the use of X-rays is encouraging
No. 2
and should be investigated further. If mac- erated limbs are used, a good estimation of age can be made by the examination of the seven areas of bone development (Fig. 12).
F. Lens Weight
All lens weights discussed are the com- bined weight of both lenses. The technique employed here is that described by Lord (1959). Each age group was examined for sexual dimorphism. Except for the ten- month-old group discussed below, no sig- nificant differences exist between the sexes (P>0.3). The data for both sexes are therefore considered as a single sample for each age, the larger sample size permitting a better mathematical comparison of the age groups. Lord likewise noted no differences between males and females and considered both sexes as a single sample.
The ranges and means for the data are presented in Figure 13. The standard devi- ation has been computed for each age group and added to the figure as two standard devi- ations on either side of the mean. This method of evaluation is especially justified since the standard deviations exceed the range of most samples.
2
D Epiphysis,
Separate Fusing
Metacarpal
Sesamoid,
Metacarpal
Sesamoid, P. Phalanx
D. Epiphysis, Radius, Ulna
Fusing
Nonstaining 5 Stained
Acromion
Process
Figure 12. age in months.
3 Stained] = Stained
= Stained 5 Stained
Summary of data on epiphyseal fusion. The numbers at the top indicate the
Age Determination of Cotton Rat 31
The one-month-old sample is quite dis- tinct. The two-month-old sample is nearly so, a small overlap of the standard deviations occurring between the two- and three-month samples. Animals up to three months, there- fore, could be quite correctly aged by this technique. For all older age groups, both the range of the sample and the area covered by the two standard deviations show at least some contiguity, especially for those groups six months or older.
Older age groups might be distinguished by making arbitrary weight values to sepa- rate them. Accordingly, horizontal lines have been added to Figure 13 at 25 and 33 mg. This permits isolation of a four- and a five- month-old age group from the three-month age group and the age group six months or older. Thus a total of five age classes can be established. Of the 62 individuals in the one- through six-month-old age groups, only three, or less than 5%, thus fall into incor- rect classes. Therefore, the dry lens weight would appear to be a very satisfactory tech- nique for age determination.
For the successful application of any aging technique, one should be aware of possible variations and their causes. The 10-, 11-,
Suture Line Visible
Fused
Suture Line Visible
16%} I)
Fusing to Scapula
Wo ho
Weight in Milligrams
i ¥2
SA SG 7 eo io i iB Age in Months
Figure 18. Dry lens weight of known-age
cotton rats. (See Figure 11 for description. )
and 12-month-old samples offer some in- sights to the problem. The limits of the two standard deviations of the 10-month sample considerably exceeded the observed range, admittedly large itself. The individuals con- stituting this sample fall into two groups: one of six females whose lens weights range from 35.6-37.8 mg, and a second group of three males whose lens weights ranged from 43.9-44.3 mg. This is the only age group where distinct differences occur between the sexes. Perhaps a more reasonable explana- tion is that the females were not autopsied until several days after being sacrificed, al-
though the specimens were frozen. Mont- gomery (1963) has shown that raccoon
lenses lose weight after being frozen for sev- eral days before autopsy.
For the 1l-month-old sample, one indi- vidual born in May and sacrificed the fol- lowing April had a lens weight of 36.7 mg. The remaining individuals of this sample were born in September and sacrificed the following August. These individuals had lens weights ranging from 40.4 to 43.2 mg. The 12-month-old samples contained one group of seven individuals born and _sacri- ficed in May whose lens weights ranged
Tulane Studies n Zoology
VolAi2
from 36.2 to 39.4 mg. The remaining four individuals of the sample were born and sacrificed in September and had lens weights of 39.6 to 43.8 mg. None of the specimens were frozen prior to autopsy. An explanation of the differences in weight might be vari- ation induced by the day length since the animals, born in different seasons, were sub- jected to the normal day length throughout this study. Also, since the animals were from several different litters this range of weight might simply indicate normal vari- ation in the older animals.
G. Field Study
The last phase of this study was an at- tempt to obtain accurate growth data from the natural habitat to be compared to the laboratory-derived growth curves which could then be evaluated and adjusted. An old field habitat was selected for releasing four-week-old laboratory-raised animals. The area had been trapped intermittently over a period of two years and was known to be suitable for cotton rats. For two months before releasing the young animals I made several trips to the area to trap out as much of the existing small mammal fauna as pos- sible, reducing competition for the young cotton rats. During the retrapping period following release of the young, only one nonmarked cotton rat was collected.
Each cotton rat to be released was toe- clipped for identification when weaned. Three or four cotton rats from the same litter were then placed in a new cage. In place of the usual tin-can nesting facilities the animals were provided with a wooden nest box approximately 6 x 6 x 4 inches high. A 2 x 2 inch opening was provided with a cover that could be closed quickly with the cotton rats inside. The nest box was trans- ported to the release area, the cover opened, and the animals left with an available nest to which they might be accustomed. A lib- eral supply of food was also placed in the nest box. I had hoped that some individuals would continue to use this shelter and thus facilitate their recapture. Many of the nest boxes appeared to be inhabited as grass and cuttings were incorporated into the nest box cotton. However, only one cotton rat was ever found in the nest box and this indi- vidual escaped before the opening could be covered. A total of 96 rats were released from March 25 to June 5, 1961
No. 2
During May the release area was ex- haustively retrapped on three occasions with collapsible Sherman live traps. Approxi- mately 200 traps were set each of the seven nights involved. The release area was also live-trapped in mid-June for five nights con- tinuously with 240 traps per night, prior to which heavy rains had inundated the release area. No cotton rats or any other small mam- mals were collected during the latter period. The field project was terminated at this time for lack of additional young available for release.
Cotton rats trapped in May were ether- ized, weighed, and measured, and examined for molting and reproductive status. They were then allowed to recover for 30 minutes and released at the same location where they were trapped. Of the 96 rats released, 12 were recaptured from one to four times for a total of 23 recaptures. Four individuals died in the live traps, presumably from the high temperature due to direct sunlight on the traps and from attacks by fire ants. The remains of the four that died were autopsied as far as possible. The date on these four animals are given in Table 2.
The weights and body lengths of all re- trapped cotton rats are plotted in Figures 14 and 15. If an individual was retrapped on several consecutive days, only the first day is plotted. Two individuals were re- captured a second time, 22 days after their first recapture. These points are connected with a line for identification.
As expected, weight increase was much slower in the field than in the laboratory. The lines on Figure 14 represent the m2zn2- mum weight of the monthly laboratory sample of each sex. The mean weight was so much greater that plotting it on the chart would have had no value for comparison.
Age Determination of Cotton Rat
Uo Wo
4 5 6 7 8 9 10 {I Age in Weeks
Figure 14. Body weights of released known- age cotton rats. The heavy line represents the minimum monthly weights from Figure 1 (upper line for males; lower line for females). The thin lines connect data for the same individual.
The difference between the laboratory and field studies probably is due to increased activity in search for food—food that also is less likely than the laboratory diet to be accumulated as body fat. Possibly the stress induced by being released into an unfamiliar and competitive habitat and/or being in the live-trap for extended periods may have af- fected the body weight. Animals recaptured on successive days showed weight losses from previous days of up to five grams. The information on body weights is too limited to construct a growth curve of wild animals. The data do strongly suggest that laboratory weights are of little use for age determina- tion of wild individuals.
The body length measurements are plotted in Figure 15. The lines in this figure repre- sent the average body length of each monthly sample. The field data appear to be quite consistent with the laboratory data, and sub- stantiate the idea that the greater body
TABLE 2. Data on released animals that died in the live traps. Skull measurements in millimeters; lens weights in milligrams.
Animal No. 356 Sex m
Age (days) 85 Condylobasilar length 34.0 Nasal length Def Lambdoidal breadth 13.6 Zygomatic breadth 18.8 Lens weight Dione
382 426 445 if f f 75 45 D5
32.6 30.5 32.4
12.1 Abe 12.5
13.3 13.0 13.2
18.4 17.6 18.0 = 13.4 z
* Data not available
34 Tulane Studies n Zoology
°
160
150
& ro)
130
Length in Millimeters
120
10
Age in Weeks
Figure 15. Body length of released, known- age cotton rats. The heavy lines represent the mean body lengths from Figure 2 (up- per line for males; lower line for females). The thin lines connect data for the same individual.
weights of laboratory animals reflect a greater amount of fat and not larger size. On the basis of these limited data, body length appears to be a useful method for age determination.
Five cotton rats were found to be molting when recaptured. Two individuals (33 and 34 days old) were completing the subadult molt. Two others (61 and 75 days old) were in the earlier stages of the adult molt. A single recapture at 84 days of age was molting dorsally, thus completing the adult molt. Five individuals captured at 43-47 days of age were not molting. Presumably they were in complete subadult pelage and would shortly begin to molt to the adult pelage. The cotton rat examined at 96 days was not molting. The individual molting data of the released animals coincide well with the observed laboratory data except that the subadult-to-adult molt may begin somewhat later and end somewhat earlier. With more field studies and an increased understanding of seasonal variation, the molting pattern for age determination could possibly be developed to a high degree.
The reproductive data are limited. One male died in the trap (age 84 days). A smear of the testis and epididymis was nega- tive but this is attributed to the carcass being severely damaged by fire ants and the length of time between death and micro- scopic examination. All males when recap- tured had the testes in the scrotal position.
One female captured at 96 days of age had considerably enlarged teats and was
Vol. 12
lactating. The vaginal orifice was imper- forate which suggests that parturition had occurred one or two days previous to cap- ture. With a normal gestation period this female probably mated at about 65 days of age. This single example of reproductive activity of a released female agrees well with the laboratory data. The reproductive tracts of the three females that died in the live traps did not show any indication of repro- ductive activity.
The teeth of the four released cotton rats that died in the traps showed the most dra- matic difference from the laboratory study. Staining of the teeth, presumably due to the diet, is very marked. The teeth are consider- ably more worn than laboratory individuals of the same age. Using laboratory tooth wear as a criterion for age determination produces an estimate two-to-four months older than the actual age. Since tooth wear is more rapid in the natural habitat, this character might be used successfully for aging, as more variability would be present and thus more stages of wear that possibly would reflect the animal’s age.
The skeletal characteristics of the released cotton rats compare well with the laboratory data. The skull measurements are listed in Table 2. The condylobasilar and nasal lengths both fall in the lower range of the known-age measurements. The lambdoidal breadth and the zygomatic width show very satisfactory agreement with the laboratory data. A good age estimation can be obtained on the basis of these two measurements..
The characteristics of the stained forelimb are in consistent agreement with the labora- tory data. The metacarpal and phalangeal epiphyses, the distal epihyses of the radius and ulna, the proximal epiphyses of the ulna, and the ossification of the acromion process and the suprascapular cartilage are all in close agreement with the laboratory data. These limbs were examined initially without the knowledge of the specimen’s exact age. The 45-, 55-, and 75-day-old specimens were all estimated to be “about two months” while the 85-day-old individual was estimated to be “three months.” These estimations appear to be as accurate an estimation as could be made with any char- acter.
The lens weights of only two of the four dead known-age individuals were in satis- factory condition for study. The eyes of the
|
No. 2
others were dried out and partially eaten by ants. As can be seen by comparing the lens weight from Table 2 with those in Figure 13, the data from the released cotton rats fit the laboratory data quite satisfactorily.
V. DISCUSSION AND CONCLUSIONS
When considering the reliability of age determination based upon laboratory data, two points must be kept in mind. First, ani- mals are not found in month-old groups but form a continuum of all ages. Thus, while one may attempt to assign an animal to a certain age group one does so with the knowledge that the age of the animal is being approximated only. The second point is estimating age from a live or a dead ani-
mal. In a live-trap study one must determine the age and then release the animals un- harmed. Such a procedure limits the number of characters that can be employed. The present study was based largely upon the interpretation of characters from dead ani- mals. I presumed that some dead-animal characteristics could be adapted to evaluate living cotton rats. One possible adaptation would be the use of X-raying in place of the maceration and staining technique.
From an examination of the data that have been presented it appears that age determination can be accomplished best for animals up to six months of age by a com- bination of several characters. Age determi- nation of older cotton rats appear virtually impossible other than to indicate an indi- vidual as being over six months of age. Precisely what age cotton rats may attain in their natural habitat is, of course, unknown. Some information on this topic has been presented by Odum (1955), who stated that an animal once trapped was never retrapped more than six months later. Assuming such an individual to be a month old or more when initially trapped, its maximum age when retrapped would probably not exceed seven to ten months. In a live-trapping study of the cotton rat in Louisiana in which I participated, cotton rats were never retrapped more than four months after the initial trap- ping. Recently Dunaway and Kaye (1964) did note two wild cotton rats approximately 10 and 11 months of age. It is not known how many other rats attained such an age.
The techniques developed in this study are felt to be satisfactory for estimating the age of wild cotton rats throughout the greater
Age Determination of Cotton Rat 35
portion of their presumed life expectancy. However, any attempt to estimate age should be based on several characters to minimize error. The most reliable characters are sum- marized in the following two paragraphs.
The computed body-length measurement is rapidly collected and is satisfactory to sepa- rate animals up to three months of age from all other animals of the population. Molting might also be used to distinguish the younger age categories, although the distinctions are less specific than body length, and the pro- cess is more easily studied from the skin side of the pelt. The molting pattern con- tinues to change fairly regularly in the labo- ratory specimens, but the information is probably inadequate for use as a critical age- determining characteristic, as molting has been shown in other rodents to vary with the seasons of the year. This particular char- acter definitely should be studied in more detail under more varied laboratory condi- tions and in the natural habitat.
Epiphyseal ossification can be determined on a dead animal by maceration and stain- ing. By comparing the several ossification areas, one can establish the approximate age of an animal to six months of age. For a live animal, epiphyseal ossification might be studied by X-raying the limb of an anesthe- tized animal. This character may have con- siderable advantage as an age-estimating technique, as ossification processes seem to proceed at a fairly constant rate and _ pre- sumably are not as subject to environmental variation as are body weight and molting. One additional charatcer that might be de- veloped for determining the age of a live cotton rat is the measurement of the zygo- matic breadth. This character was studied only on clean skulls but proved quite ac- curate for estimating age. Since the amount of flesh covering the zygomatic arch of the live animal is quite limited, this measure- ment might be adapted for estimating age. The lens weight data are very useful for age determination. There is no clear separation of the four- and five-month-old animals, but these two ages are distinguishable from all younger age groups and from all older ani- mals. As the moment nothing is known of the factors, other than freezing, that may cause variation in the lens weight. Thus by a combination of the above techniques, one should be ab!e to closely approximate the
2
age of a given animal based upon the labo- ratory data.
One very difficult problem to evaluate is the difference between growth of a labora- tory specimen and growth of a wild spect- men in its natural habitat. That such a dif- ference exists is easily shown by the fact that the laboratory cotton rats used in this study were considerably heavier than their counterparts released in the field at an age of 4 weeks. However, this may be only part of the picture. Unknown and impossible to evaluate is the effect of preweaning growth on the cotton rat before it is released. All cotton rats, prior to release, recetved what might be considered an adequate if not optimal diet. Presumably by this time the subsequent growth pattern has been largely determined. Similarly difficult is the prob- lem of evaluating the health and nutrition of the female cotton rat prior to conception. A female in good health could be expected to produce healthier young than a female in poor health. Thus not only the early pre- weaning growth but even the prenatal de- velopment of the animals that were released was undoubtedly affected by the laboratory environment. One possible mechanism for evaluating sucn changes would be to collect pregnant cotton rats from the field and al- low them to have their litters in the labora- tory. Immediately after birth the animals could be toe-clipped, and then the female and her litter released into the natural en- vironment, possibly in a large enclosure. Dunaway and Kaye (1964) toe-clipped young cotton rats born in live traps. Pre- sumably these individuals are the known-age animals they discuss. This method is the best way of obtaining known-age animals in their hab‘tat, although perhaps limited in numbers of individuals.
Several studies have attempted to esti- mate the age of the cotton rat. Erickson
1949) classified each individual as either immature or adult but did not give any basis for these age classes. Since the basic purposes of the study were calculations of movement and density, age determination was not particularly important.
Similarly, Stickel and Stickel (1949) studied the home range of the cotton rat in Texas. They recognized four age Classes based primarily on size and breeding condi- tion. Only approximate body-length meas- urements were taken, and these were not
36 Tulane Studies n Zoology
Well, i
listed by the authors. The age classes were thus rather subjectively determined. Their two youngest age Classes probably correspond to one- and two-month old animals as used in this study.
Sealander and Walker (1955) conducted a study of the cotton rat in northeastern Arkansas. Age classes were initially defined on the basis of actual or potential reproduc- tion. Thirty days was considered the age at which cotton rats might begin breeding. The laboratory growth data of Meyer and Meyer (1944) were then employed to form weight limits to each age class. The age classes were subadult, 10 to 29 days; young adult, 30 to 50 days; old adult, 51 to 250 days. On the basis of the age classes as determined by using body weight, these authors found an age distribution during the late winter and early spring that indicated a high percentage of young individuals in population. This, in spite of the fact
hat breeding had ended the previous No- ae and had not yet resumed. Thus weight used as an age criterion did not pro- duce an age distribution that agreed with the field data. These authors also noted that considerable body fat accumulated by the cotton rats in November and December, declined drastically in January and February to about 60% of the peak December value, and disappeared in April. Presumably this body fat is used as an energy source during the period of its decline. Thus, while the animals are actually becoming older they are losing weight, a fact which would place ani- mals in younger age categories. In theory, weight might be used as an aging technique during the severe winter period if one could take into consideration the probable weight loss in each individual at this time. How- ever, it would be incorrect to assume that the same rate of body weight decline is present during each winter.
Odum ( 1955) concurrently studying cot- ton rat Fe ater over a period of 11 years, presents data that may give a truer picture of the normal weight ca He captured a 15-gm female on June 6, 1949. On the basis of an average birth weight of 7 gm and a gain of 1 gm a day (Svihla, 1929; Meyer and Meyer, 1944), the above individual was adjudged to be a week old when captured. It was recaptured on August 21, at a pre- sumed age of 159 days and a weight of 96 gm. A second female weighed 74.5 gm on
No. 2 August 21, and two and one-half months later, on November 9, weighed 103 gm.
Judging from my release records, this sec- ond female was two to three months old when first caught and, therefore, about five months old at the weight of 103 gm. While limited, the data do give some idea of the rate of weight gain by wild cotton rats. According to the weight limits of the age categories employed by Sealander and Walk- er, these two females would have been classi- fied as young adults (age 30-50 days). Odum’s study of cotton rat populations was based largely on spring (May) and fall (November) trapping. The primary pur- pose of his study was to follow the periodic changes in population density. The trap- ping program employed served the purpose well, as Odum’s methods avoided the prob- lematic period of winter weight loss. Dunaway and Kaye (1964) mention a male and two female cotton rats weighing 103, 95, and 101 gm, respectively, at an age of 104 days when trapped in November. A male and a female 119 days of age when captured in February weighed only 88 and 77 gm, respectively, however, and a 117 day old male weighed only 75 gm at this time. Also, a female, age unknown, weighed 62 gm in September, 87 gm in November, but only 84 gm in February. In addition to emphasizing the severe effects of winter, the data point out the impossibility of using laboratory weight for age estimation. The three 314-month-old cotton rats trapped in November fall in the weight range of 2 month old laboratory rats. Using Odum’s (1955) criteria, these animals would have been placed in the 2-to-5-month-old category. The information on growth rates and re- productive activity of known-age individuals in the natural habitat is too limited for spe- cific conclusions. However, where available, data from cotton rats released in the present study either show close agreement with the laboratory data or else give indication that the laboratory data might be modified to allow for an adequate age estimation. Body weight is a useful age-determining technique at certain seasons of the year, but should not be employed during the period January- through-April except with extreme caution. The other techniques described in this study should be more useful than weight for age determination, especially during the winter. Finite evaluation of age-determining tech-
Age Determination of Cotton Rat oy
niques should be based on releasing and re- trapping young known-age individuals at all seasons of the year.
VI. ACKNOWLEDGEMENTS
I wish to express my sincere appreciation to the following people: Dr. Norman C. Negus under whose direction this study was carried out; Robert C. Feuer and Dan Gold- berg for timely assistance in the laboratory and field; and my wife for patience, en- couragement, and assistance in all phases of this study.
VII. REFERENCES CITED
ALEXANDER, MAURICE M. 1958. The place of aging in wildlife management. Amer. Sct. 46: 123-137.
. 1960. Shrinkage of musk-
‘rat skulls in “relation to aging. J. Wildl. Mgmt. 24: 326-329.
CLARK, RENE H. 1936. The estrous cycle
of the cotton rat. Contr. Lab. Vert. Ge- netics. No. 2. 2 pp. DUNAWAY, P. B., and S. V. KAYE 1964.
Weights of cotton rats in relation to sea- son, breeding and environmental radio- active contamination. Am. Midland Nat- uralist, 71: 141-155.
ERICKSON, ARNOLD B. 1949. Summer popu- lations and movements of the cotton rat and other rodents on the Savannah River Refuge. J. Mammal. 30: 133-140.
GREEN, EUNICE C. 1949. Gross anatomy. In: The Rat in Laboratory Investiga- tions. Edmond J. Farris and John G. Griffith, Jr., editors. Second edition. J. B. Lippincott Co., Philadelphia, i-xiv; les
HAINES, HowArp 1961. Seasonal changes in the reproductive organs of the cotton rat, Sigmodon hispidus. Texas J. Sci., 13: 219-230.
cae CHARLES E. 1958. The rate of devel- opment of Sigmodon hispidus as com- pared with some other rodents. Trans. Kentucky Acad. Sci., 19: 25-27.
Lorp, RExForD D., JR. 1959. The lens as an indicator of eS an cottontail rabbits. J. Wildl. Mgmt., 23: 358-360.
McINTIRE, J. M., B. G. SCHWEIGERT, and C. H. ELVEHJEM 1944. The nutrition of the cotton rat Sigmodon hispidus hispi- dus. J. Nutrition, 27: 1-9.
Meyer, D. B., and MARTHA MarsH 19438. Development and management of a cot- ton rat colony. Am. J. Publ. Health, 33: 697-700.
MEYER, B. J.,. and R. K. Meyer 1944. Growth and reproduction of the cotton rat Sig- modon hispidus hispidus under laboratory conditions. J. Mammal., 25: 107-129.
38 Tulane Studies n Zoology
MoHN, MELVIN P. 1958. The effects of dif- ferent hormonal states on the growth of hair in rats. In: The Biology of Hair Growth, pp. 335-398. William Montagna and Richard A. Ellis, editors. Academic Press Inc., New York. i-xvii, 1-520.
MONTGOMERY, G. G. 1963. Freezing, decom- position and raccoon lens weight. J. Wildl. Mgmt., 27: 481-483.
OpUM, EUGENE P. 1955. An eleven year history of a Sigmodon population. J. Mammal., 36: 368-378.
RABASA, S. L. 1952. Growth rate of the
Vol. 12
white rat in relation to the number per cage. Physiol. Zool., 25: 98-108.
SEALANDER, JOHN A., JR., and BARRY Q. WALKER 1955. A study of the cotton rat in northwestern Arkansas. Proc. Arkan- sas Acad. Sci., 8: 153-162.
STICKEL, LUCILE F. and WILLIAM H. STICK- EL 1949. A Sigmodon and Baiomys popu- lation in ungrazed and unburned Texas prairie. J. Mammal. 30: 141-150.
SvIHLA, ARTHUR 1929. Life history notes on Sigmodon hispidus hispidus. J. Mam- mal., 10: 252-253.
DIGENETIC TREMATODES OF MARINE FISHES FROM APALACHEE BAY, GULF OF MEXICO
FUAD M. NAHHAS*
and ROBERT B. SHORT, Department of Biological Sciences, Florida State University, Tallahassee, Florida
CONTENTS
F ABSTRACT ee 39 I]. ACKNOWLEDGMENTS __ Pee a ae 39 Li IN ERODUGTION AND METHODSS 2... ee es 40 IV. DESCRIPTION AND DISCUSSION OF SPECIES___........--------------_- ee. ae a eA) Bamilly A porocotyiidde 2. €2 oa. i ee een eee 40 Family Bucephalidae__ Le sl 4O Family Fellodistomatidae_.._____»_»______ E 4] Family Haplosplanchnidae 4l HaniliysGoroodenidde: 2. ests 2a Pi aed ee Se ee ee 2 eee 41 Hanillys@ pechclidge sn oe ke ee ee ee 41 amtivsepocteadiicac si. sa aks waar ies ne ls ue meer ens ee) oe ee 42 amily Gryprosenimidae sa 2 eee eee anally Acanthocolpidata< sess eee en ee A eee a Se eee Family Hemiutidae-22. = 2 is eee A CS oe eS asia 1 ee A) RannilyeSclerodistomidae 2: 2s) a ee ee ee ees
By arc EIMAIN ACAI 2 an ne sR nee RT eee a See Ee eee Lea ee 48 Rit SALPHABERICAT: HOST=-PARASITE LIST. 2.25.2 2) en es 48 VIL. List OF FISHES NEGATIVE FOR TREMATODES....._..--_--_ 49 ARUP ERENCES CITED: ss ok © ae Oe ee ee ee 49
I. ABSTRACT
Forty-eight species of Digenea are reported from 43 species of fishes from Apalachee Bay, Florida. Three new species are described: Genitocotyle ca- blei (Opecoelidae), Lepocreadium bre- voortiae (Lepocreadiidae) and Pseudo- acanthostomum floridensis (Cryptogo- nimidae). Fourteen new locality rec- ords bring to 109 the species of Digenea known from Tampa Bay and the north-
* Present address: Department of Bio- logical Sciences, University of the Pacific, Stockton, California.
ern Gulf: 27 species from the Texas coast, 50 from Louisiana, 16 from Mis- sissippi, 31 from Tampa and Boca Cie- ga Bays, and 48 from Apalachee Bay.
Il. ACKNOWLEDGMENTS
Thanks are due a number of people, par- ticularly Professor Ralph W. Yerger for the identification and nomenclature of fishes, and to Mr. Theodore Booden and Mr. Edwin Powell for assistance in the collection of material. The authors also wish to acknowIl- edge the financial support of the Institute of
EDITORIAL COMMITTEE FOR THIS PAPER:
RAYMOND M. CABLE, Professor of Zoology, Department of Biological Sciences, Purdue University, Lafayette, Indiana
HAROLD W. MANTER, Professor of Zoology, Department of Zoology and Physiology, University of Nebraska, Lincoln, Nebraska
FRANKLIN SOGANDARES-BERNAL, Associate Professor of Zoology, Department of
Zoology, Tulane University, New Orleans, Louisiana
aby
40 Tulane Studies n Zoology
Molecular Biophysics of the Florida State University during residence of the first author as a postdoctoral fellow in the De- partment of Biological Sciences.
Ill. INTRODUCTION AND METHODS
Work on the adult digenetic trematodes of marine fishes of the Gulf of Mexico has been summarized or reviewed by Manter (1954) and Sparks (1960). To date 190 species are known from Tortugas compared with 87 from other parts of the Gulf: Tampa and Boca Ciega Bays (31), Mississippi (16), Louisiana (50), and Texas (27). In con- trast, only four species have been reported from Apalachee Bay in the northeastern part of the Gulf. Short (1953, 1954) reported two new species of aporocotylids, Kruse (1959) redescribed Opecoeloides fimbriatus (Linton, 1934) Sogandares-Bernal and Hut- ton, 1959, and Riggin and Sparks (1962) described a new bucephalid. The present paper adds 44 species to the Apalachee Bay; some are reported for the first time from the Gulf of Mexico. Not included are six spe- cies of monorchiids and zoogonids which will be reported elsewhere. The present sur- vey was conducted mainly over a 10-week period during the summers of 1963 and 1964, and consists of the examination of more than 300 individuals representing 63 species of fishes, taken from Alligator Har- bor, Mud Cove, Dog Island Reef, off St. Marks light house, and off St. George Island in the Apalachee Bay. The fishes were ob- tained by several methods including traps, nets, line, and the use of rotenone. Hosts were examined shortly after their death; in a few instances their viscera were kept in 0.7% saline for less than six hours in jars placed on ice. The worms were washed in saline, studied alive whenever time per- mitted, and fixed in Alcohol-Formalin-Acetic acid (A.F.A.) under light cover slip pressure. An attempt was made to relax some of the trematodes in chloretone before fixation, but the results were not satisfactory, particularly in the case of the hemiurids. The specimens were stained with either Semichon’s carmine, Harris haematoxylin, or Ehrlich’s acid hae- matoxylin, dehydrated in a graded series of ethyl alcohol, cleared in terpineol, and mounted in damar. Figures were drawn with the aid of a microprojector or a camera lucida, except for Figure 5 which was traced from a photograph. Measurements are in
Vol. 12
millimeters except where indicated other- wise. All host names are those used in American Fisheries Society Special Publica- tion No. 2, 1960, “A list of Common and Scientific Names of Fishes from the United States and Canada.” Holotypes of new spe- cies as well as specimens of some known ones are deposited in the U. S. National Museum Helminthological Collection. An asterisk indicates a new host record; two asterisks, a new locality record for the north- ern Gulf.
IV. DESCRIPTION AND DISCUSSION OF SPECIES
FAMILY APOROCOTYLIDAE Odhner, 1912
Cardicola laruet Short, 1953 Hosts: Cynoscion arenarius; C. nebulosus Site: heart Localities: Alligator Harbor; St. George Island
Selachohemecus olsoni Short, 1954 Host: Scoliodon terrae-novae Site: heart Locality: Alligator Harbor This species was not found in the present study but is listed to give a more complete record of adult trematodes of the area.
FAMILY BUCEPHALIDAE Poche, 1907
Bucephalus varicus Manter, 1940 Hosts: Caranx crysos; C. hippos Site: ceca Localities: Alligator Harbor; Dog Island Reef
Bucephaloides arcuatus (Linton, 1900) Hopkins, 1954**
Synonyms: Gasterostomum arcuatum Lin-
ton, 1900; Gasterostomum sp. Linton, 1900; Bucephalopsis arcuatus (Linton) Eck- man, 1932
Hosts: *Pomatomus saltatrix; Scombero- morus maculatus
Site: intestine
Locality: Dog Island Reef
Deposited specimen: US.N.M. No. 60080
Bucephaloides bennetti Hopkins & Sparks, 1958
Host: Paralichthys albigutta
Site: intestine
Locality: Alligator Harbor
No. 2
Bucephaloides caecorum Hopkins, 1956 Host: Batrdiella chrysura
Sites: ceca and intestine
Locality: Alligator Harbor
Bucephaloides megacirrus Riggin & Sparks, 1962 Host: Sciaenops ocellata Site: intestine Locality: Alligator Harbor
Rhipidocotyle baculum (Linton, 1905 ) Eckman, 1932**
Synonyms: Gasterostomum baculum Lin- ton, 1905; Gasterostomum sp. Linton, 1900; Nannoenterum baculum (Linton, 1905 )
Host: Scomberomorus maculatus
Site: intestine
Locality: Dog Island Reef
Rhipidocotyle transversale Chandler, 1935
Synonym: Prosorhynchus grascilescens (Rud.) of Linton, 1940
Hosts: Strongylura marina; *S. notata
Site: intestine
Locality: Alligator Harbor
Prosorhynchus atlanticum Manter, 1940* *
Synonym: Gasterostomum sp. Linton, 1910
Host: Mycteroperca bonaci
Site: intestine
Locality: Alligator Harbor
A single specimen was found; eggs meas- ured 32-35 by 21-23 microns.
FAMILY FELLODISTOMATIDAE Nicoll, 1913
Tergestia pectinata (Linton, 1905 ) Manter, 1940
Synonyms: Distomum pectinatum Linton, 1905; Theledra pectinata (Linton) Linton, 1910
Hosts: Bairdiella chrysura; Caranx crysos; C. hippos
Site: intestine
Localities: Alligator Harbor; Dog Island Reef
Steringotrema corpulentum (Linton, 1905 ) Manter, 1931 Synonym: Distomum corpulentum Lin- ton, 1905 Host: Lagodon rhomboides Site: intestine
Locality: Alligator Harbor
Trematodes of Marine Fishes 41
FAMILY HAPLOSPLANCHNIDAE Poche, 1925
Schikhobalotrema acutum (Linton, 1910) Skrjabin and Guschanskaja, 1955**
Synonyms: Deradena acuta Linton, 1910; Haplosplanchnus acutus (Linton) Manter, 1937
Host: Strongylura marina
Site; intestine
Locality: Alligator Harbor
Deposited specimen: U.S.N.M. No. 60081
Schikhobalotrema sp. Host: Mugil cephalus Site: intestine Locality: Alligator Harbor
The four specimens found are not favor- able for study. They probably represent a new species of haplosplanchnid.
FAMILY GORGODERIDAE Looss, 1901
Nagmia floridensts Markell, 1953 Host; Dasyatis sabina Site: body cavity Locality: Alligator Harbor
A great deal of confusion exists regarding generic features in the Anaporrhutinae, and the validity of the genus Nagmia has been questioned by Johnston (1934) and others. Nagmia floridensis was described from a single specimen, and the vitellaria were re- ported as partly medial and partly ventral to the ceca. Our material shows variation in their position, with the majority of the worms having vitellaria partly extracecal and partly overlapping the ceca ventrally. Two immature specimens show clearly the ex- cretory vesicle as Y-shaped; in adults, the unbranched stem is seen but its arms are concealed.
FAMILY OPECOELIDAE Ozaki, 1925
Opecoeloides fimbriatus (Linton, 1934) Sogandares-Bernal and Hutton, 1959
Synonym: Cymbephallus fimbriatus Lin- ton, 1934
Hosts: Bairdiella chrysura; Menticirrhus americanus; *M. focaliger; M. littoralis; Mr- cropogon undulatus; Sciaenops ocellata
Site: intestine
Localities: Alligator Harbor; Mud Cove; St. George Island
The original description by Linton is in- adequate and the species has been redescribed
42 Tulane Studies n Zoology
by Sogandares-Bernal and Hutton (1959b), and by Kruse (1959) from Linton’s type specimen and additional ones collected from Apalachee Bay. The single specimen from Micropogon undulatus has a smaller sucker ratio (1:1.17) and fewer acetabular papillae (exact number cannot be determined). On the basis of these features, it should perhaps be referred to O. polynemt Von Wicklen, 1946. Sogandares-Bernal and Hutton (1959c) questioned the validity of O. poly- nem1,; in sucker ratio (1:1.25) it comes close to the lower limit found in some of our specimens from the other hosts (range 1: 1.3- 1.8). The papillae on the acetabulum may be retracted and thus may be indiscernible; Kruse (1959) reported “four lobes each hav- ing from five to nine papillae” and Sogan- dares-Bernal and Hutton (1959b, Fig. 13) show 6, 6, 6, and 8 papillae per lobe. No such variation, however, is reported by Von Wicklen in her 10 specimens of O. polynemz.
Genitocotyle cablei n.sp. Figure 1
Host: Ancylopsetta quadrocellata Site: intestine
Locality: Dog Island Reef Holotype: U.S.N.M. No. 60082
Description and measurements based on two specimens. Body elongated, 2.70-2.93 long, 0.567-0.600 wide. Oral sucker 0.165- 0.185 in diameter; ventral sucker in anterior third of body, pedunculate, 0.268-0.294 in diameter, with three or four small papillae on anterior and posterior margins; sucker ratio 1:1.54-1.62. Accessory “sucker” pit- like and without a limiting membrane, sur- rounded by a few cells, about half-way between pharynx and ventral sucker. Pre- pharynx short; pharynx large, 0.155 in di- ameter; esophagus slender, 0.294-0.360 long; cecal bifurcation at level of anterior margin of ventral sucker; ceca ending blindly near posterior end of body. Testes two, smooth, tandem, close together, 0.232-0.309 in di- ameter. Cirrus sac absent; seminal vesicle tubular, reaching posteriorly halfway be- tween ventral sucker and ovary; ejaculatory duct very long and slender, extending from posterior end of acetabulum to level of pos- terior margin of pharynx. Ovary entire, pretesticular, 0.155-0.180 in diameter; semi- nal receptacle absent; uterus preovarian; eggs 56-64 by 31-36 microns. Genital pore
Vol?
ventral, slightly sinistral, near level of pos- terior margin of pharynx. Vitelline follicles extending from level of posterior margin of ventral sucker to posterior end of body, con- fluent in posttesticular space. Excretory vesi- cle tubular, extending to ovary.
This species is referred to the genus Genittocotyle Park, 1937, on the basis of an accessory sucker (preacetabular pit) and blind ceca, conditions determined on live material as well as on frontal sections of one of the two specimens. Unlike other mem- bers in the genus, this species has acetabular papillae. We do not feel, however, that a new genus is justified on that basis.
Genitocotyle cablei differs from the other three species in the genus in having acetabu- lar papillae. It further differs from G. acirra Park, 1937, in the position of the genital pore, in lacking a limiting membrane around the accessory sucker, and in having smaller eggs; from G. atlantica Manter, 1947, chiefly in extent of vitellaria and shape of the gonads; and from G. heterosticht Mont- gomery, 1957, in extent of vitellaria, posi- tion of the genital pore and seminal vesicle, and in lacking a limiting membrane around the accessory sucker. Neither the whole mount nor the frontal sections in our lim- ited material show a true seminal receptacle. Such a structure is also reported as absent in G. heterosticht but present in the other two species. This structure is of generic value, at least in some opecoelids.
The species is named in honor of Pro- fessor R. M. Cable of Purdue University, Lafayette, Indiana, in recognition of his con- tributions to the knowledge of the Trematoda.
FAMILY LEPOCREADIIDAE Nicoll, 1934
Lepocreadinm brevoortiae n.sp. Figure 2 Host: Brevoortia patronus Site: intestine Localities: Alligator Harbor; Mud Cove Holotype: U.S.N.M. No. 60083
Description and measurements based on 20 specimens. Body elongated, tapering an- teriorly, rounded posteriorly, 0.850-1.140 long, 0.260-0.390 wide. Cuticle spinose; eye spot pigments diffuse. Oral sucker sub- terminal, 0.078-0.108 in diameter; ventral sucker in mid-third of body, sometimes equa-
No. 2
torial, 0.072-0.090 in diameter; sucker ratio 1:0.85-1.00. Prepharynx absent or very short; pharynx massive, sometimes larger than oral sucker, 0.080-0.096 in diameter; esophagus about half to one and a half length of pharynx; cecal bifurcation about midway between suckers; ceca extending to level of posterior vitelline follicles. Testes two, tire, tandem, contiguous, 0.072-0.150 in di- ameter. Cirrus sac long, about 1/4 body length, sometimes reaching ovarian zone, containing subspherical internal seminal vesicle, large pars prostatica, and long mus- cular spiny cirrus; spines of cirrus minute, sometimes partially lost; external seminal vesicle saccate, often overlapping ovary dor- sally. Ovary triangular in shape, contiguous with anterior testis, 0.060-0.096 in diameter; seminal receptacle postovarian; uterus pre- ovarian. Eggs 60-66 by 31-41 microns. Vi- telline follicles extending from level of in- testinal bifurcation to near posterior end of body, confluent in posttesticular space. Genital atrium small; genital pore preace- tabular, sinistral. Excretory vesicle tubular, anterior extent not determined; excretory pore terminal.
en-
The combination of a massive pharynx any spiny cirrus distinguish Lepocreadiam brevoortiae from all the other 21 species in the genus. The massive pharynx is a con- stant feature not due to excessive flattening and was seen in the live material obtained from 13 fish from two localities. A large pharynx is described for L. znciswm Hanson, 1955 and L. clavatum (Ozaki, 1932); Yama- guti, 1938 but both species lack a spiny cirrus, the cirrus sac does not extend pos- terior to the ventral sucker, and the ovary and testes are lobed. L. pyriforme (Linton, 1900) Linton, 1940 has a spiny cirrus. Sogandares-Bernal & Hutton (1960) dis- cussed this species and concluded that there are several species involved in Linton’s de- scriptions. Nahhas & Cable (1964) ac- cepted as this species only individuals that are similar to Figure 47 (Linton, 1940) or Figure 9 (Sogandares-Bernal & Hutton, 1960). On this basis, L. brevoortiae would differ from L. pyriforme by having a larger pharynx, shorter prepharynx, and more an- terior extent of the vitellaria.
Trematodes of Marine Fishes 43
Lepocreadium floridanus Sogandares-Bernal and Hutton, 1959
Lagodon rhomboides intestine Alligator Harbor
Three specimens are in close agreement with the description of Sogandares-Bernal and Hutton (1959a) except for a somewhat oval body shape rather than an elongated one. In one specimen, the testes were slightly oblique. Egg size was not given in the original description of the species. In our material the range is 54-72 by 26-38 microns.
Another group of more elongated worms with vitellaria extending only to the acetabu- lum, was found in the same host species. They were first thought to be Lepocreadium pyriforme (Linton, 1900) as limited in the discussion of the previous species. However, the cirrus lacks spines and for the time being the trematodes are considered as younger forms of Lepocreadium floridanus,
Host: Site: Locality:
Opechona gracilis (Linton, 1910 ) Manter, 1947** Figure 3 Synonym: Prodistomum gracile Linton, 1910; nec Opechona gracilis (Manter, 1931) Ward & Fillingham, 1934 Host: *Peprilus alepidotus Site; intestine Locality: Mud Cove
Deposited specimen: U.S.N.M. No. 60084
The present material is referred to this species on the basis of shape of the ovary, extent of vitellaria and excretory vesicle, sucker ratio and other measurements. Our specimens differ, however, in egg size and in having a definite prepharynx varying in length from about one half to one and half the length of the pharynx. The eggs in our material are collapsed and measure 72- 82 by 30-37 as compared with 61-64 by 37-47 microns (Manter, 1947).
Apocreadium mexicanum Manter, 1937**
Host: Monacanthus hispidus
Site: intestine
Locality: Alligator Harbor
This species was first described by Manter from the Pacific Coast. Siddiqi and Cable (1960) reported it from Puerto Rico but noted “slight differences in sucker ratio, width of eggs, and length of posttesticular
44
space.” Nahhas and Cable (1964) found this species in Monacanthus hispidus in Ja- maica and noted that their specimens were “more like those of Siddigi and Cable (1960 ) ’ and that “the posttesticular space usually is less than half as long as the body but sometimes the two regions are about equal in length.” Eggs of the Florida material measure 70-84 by 30-48 microns compared with 63-71 by 42-45 microns for the Jamaican material. Manter (1937) gave an egg size range of 61-67 by 31-34 microns.
Homalometron pallidum Stafford, 1904 Host: Letostomus xanthurus
Site: intestine
Locality: Alligator Harbor
Multitestis inconstans (Linton, 1905 ) Manter, 1931** Synonym: Distoma inconstans Linton, 1905 Host: Chaetodipterus faber Site: intestine Locality: Alligator Harbor
Deposited specimen: U.S.N.M. No. 60085
Diploproctodaeum plicitum (Linton, 1928 ) Sogandares-Bernal & Hutton, 1958
Synonyms: Distomum sp. of Linton, 1898 and 1905; Psilostomum plicitum Linton, 1928; Biantum concavum Stunkard, 1930; B. adplicatum Manter, 1940; B, plicitum (Linton) Stunkard, 1931
Host: Chilomycterus schoepfi
Site: intestine
Locality: Alligator Harbor
Dermadena lactophryst Manter, 1946**
Synonym: Distomum lamelliforme Lin- ton, 1907 in part
Host: Lactophrys quadricornis
Site: intestine
Locality: Alligator Harbor
Deposited specimen: U.S.N.M. No. 60086
FAMILY CRYPTOGONIMIDAE Ciurea, bys) Siphodera vinaledwardsu (Linton, 1899 ) Linton, 1910
Synonym: Monostomum vinaledwardsu Linton, 1899
Host: Opsanus beta
Site: intestine
Locality: Alligator Harbor
Tulane Studies in Zoology
Metadena adglobosa Manter, 1947** Host: *Paralichthys albigutta Site: ceca Locality: Alligator Harbor
Two specimens, one mature but damaged, and one immature, were recovered along with a number of individuals of Bucepha- loides bennetti. The egg size and that of the oral sucker relative to body width are char- acteristic of this species. This species has hitherto been known only from snappers of the genus Lutjanus.
Pseudoacanthostomum floridensis n.sp. Figure 4
Synonym: Pseudoacanthostomum pana- mensis of Corkum, 1959, nec Caballero et al., 1953
Host: Galetchthys felis
Site: intestine
Locality: Alligator Harbor
Holotype: US.N.M. No. 60087
Description and measurements based on two specimens, one sectioned frontally. Body elongated, 2.63-3.00 long, 0.489-0.750 wide. Cuticle with spines extending to level of posterior testis; eye spot pigments pres- ent. Oral sucker like an inverted bell, 0.180- 0.294 long, 0.309-0.330 in greatest width; mouth surrounded by single row of 28 pe- rioral spines measuring 42-60 by 18-24 microns; ventral sucker in anterior third of body, 0.118-0.155 long, 0.155-0.170 wide; sucker ratio 1:0.54. Prepharynx contracted in holotype, longer than pharynx in para- type; pharynx 0.129-0.206 in diameter; esophagus very short; ceca extending to pos- terior end of body, and joining excretory vesicle by two narrow ducts a short distance anterior to excretory pore. Testes two, ovoid or rhomboid, tandem, well separated, 0.283- 0.309 long, 0.180-0.283 wide; seminal vesi- cle tubular, sinuous, extending posteriorly to about halfway between ventral sucker and ovary; prostate cells free in parenchyma. Ovary trilobed, about midway between ven- tral sucker and anterior testis, 0.232-0.260 long, 0.298-0.309 wide; seminal receptacle spherical, preovarian; uterine coils extending to near posterior tips of ceca. Genital pore median, immediately preacetabular; gonotyl as large as ventral sucker, the two sometimes
overlapping. Eggs 20-25 by 11-14 microns. |
Vitelline follicles small, sometimes granular, extending from anterior testis laterally and
I
No. 2
dorsally some distance anterior to ventral sucker but not reaching intestinal bifurca- tion. Excretory vesicle Y-shaped, wide arms extending from near posterior testis to mid- level of pharynx; pore terminal.
This is the second species in the genus Pseudoacanthostomum. P. floridensis dif- fers from P. panamensts Caballero, Bravo H. and Grocott, 1953 from Galeichthys seemant from the Pacific Coast in the number of perioral spines (28 compared with 26), greater extent of the vitellaria, and the pres- ence of a uroproct. This last feature was suspected in the live material and confirmed by frontal sectioning of the paratype.
Corkum (1959) reported a single speci- men with 28 perioral spines as P. panamensts from Galeichthys felis. We have borrowed this specimen and found it to agree with our material also in the distribution of the vi- tellaria. The connections of the ceca with the stem of the vesicle could not be deter- mined as they were concealed by the uterine coils. Figure 5 is a tracing of a photomicro- graph of Corkum’s material.
FAMILY ACANTHOCOLPIDAE Luhe, 1909 Stephanostomum ditrematis (Yamaguti, 1939) Manter, 1947
Synonyms: Echinostephanus ditrematts Yamaguti, 1939; Stephanostomum longiso- mum Manter, 1940; Stephanostomum filt- forme Linton, 1940
Host: Caranx hippos
Site: intestine
Locality: Alligator Harbor
Stephanostomum interruptum Sparks & Thatcher, 1958 Hosts: Batrdiella chrysura; Cynoscion are- narius; C. nebulosus Site: intestine Locality: Alligator Harbor
Stephanostomum megacephalum Manter, 1940
Host: Caranx hippos
Site: intestine
Locality: Alligator Harbor
Stephanostomum sentum (Linton, 1910) Manter, 1947** Synonym: Stephanochasmus sentus Lin- ton, 1910 Host: *Menticirrus americanus Site: intestine Locality: Alligator Harbor
Trematodes of Marine Fishes 45
Stephanostomum metacercaria
Host: Monacanthus hispidus
Site: wall of the heart
Locality: Alligator Harbor
A single specimen, with 34 perioral spines and an oral sucker smaller than the ventral sucker, was found encysted on the wall of the heart.
Pleorchis americanus Lihe, 1906
Synonyms: Distomum polyorchis Linton, 1901 nec Stossich, 1888; Distoma molle (Leidy, 1856) Stiles & Hassall, 1894; Pleorchis mollis (Leidy, 1856) Stiles, 1896; Pleorchis lintoni Yamaguti, 1938; Polyorchis molle (Leidy, 1856) Mont., 1896
Hosts: Cynoscion arenarius; C. nebulosus
Site: intestine
Localities: Alligator Harbor; Dog Island Reef; St. Marks
FAMILY HEMIURIDAE Luhe, 1901
Aponurus laguncula Looss, 1907 Hosts: *Centropristis melanus; *Lago- cephalus laevigatus; *Paralichthys albigutta Site: stomach Localities: Alligator Harbor; Dog Island Reef; St. George Island
Fourteen worms collected from three fishes are 0.541-1.275 long, 0.138-0.335 wide. We first thought that three worms from Lago- cephalus laevigatus represented a different species because they were larger (1.200- 1.275 by 0.319-0.335) than those from the other two hosts (0.541-0.849 by 0.138- 0.180) and their eggs were slightly thicker- shelled, narrower at one end, and measure 30-32 by 17-18 compared with 26-31 by 14-17 microns. Egg measurements overlap, and proportions of organs are the same, how- ever. In body size and egg shape, the three larger trematodes are similar to A. trachinott Manter, 1940 but this species has smaller eggs (25 by 10 microns).
Aponurus elongatus Siddiqi & Cable, 1960**
Host: Chaetodipterus faber
Site: stomach
Localities: Alligator Harbor; Dog Island Reef
Deposited specimen: U.S.N.M. No. 60088
Three specimens found in this study agree closely with the description of Siddiqi & Cable (1960) but differ in having slightly
46 Tulane Studies in Zoology
larger eggs (28-35 by 16-18 compared with 26-29 by 13-16 microns). Siddigi and Cable did not distinguish their species from others in the genus. It is most similar to A. lagun- cula but differs in sucker ratio (1:2.5 com- pared to 1:1.7-2.1) and in having a more elongate body, more anterior ventral sucker, a greater postovarian space, and vitellaria that are longer than wide. A. elongatus is known only from Chaetodipterus faber and has been reported from Puerto Rico, Jamaica, and now from Apalachee Bay.
Lecithaster confusus Odhner, 1905 ** Synonym: Distomum bothryophoron Ols- son of Linton, 1899 Hosts: *Brevoortia patronus; *Lagodon rhomboides Site: intestine Locality: Alligator Harbor
Parahemiurus merus (Linton, 1910) Woolcock, 1935
Synonyms: Hemiurus merus Linton, 1910; Parahemiurus parahemiurus Vas & Pereira, 1930; P. platichthyi Lloyd, 1938; P. atherinae Yamaguti, 1938; P. harengulae Yamaguti, 1938
Hosts: Brevoortia patronus; Cynoscion nebulosus; *Lagodon rhombotdes
Site: stomach
Locality: Alligator Harbor
Sterrhurus monticelli (Linton, 1898 ) Linton, 1910 Synonym: Distomum monticelli Linton, 1898 Host: Pomatomus saltatrix Site: stomach
Locality: Dog Island Reef
Sterrhurus musculus Looss, 1907
Synonyms: Sterrhurus laeve (Linton) of Manter, 1931; Sterrhurus floridensis Manter 1934 in part
Hosts: * Ancylopsetta quadrocellata; * An- guilla rostrata; *Batrdiella chrysura; *Cen- tropristis melanus; *Diplectrum formosum; *Letostomus xanthurus; Menticirrhus amert- canus; *Mtcropogon undulatus; *Ogco- cephalus radiatus; *Ophidion welsht; *Op- sanus beta; *Orthopristis chrysopterus; *Paralichthys albigutta; *Syacium papil- losum; Synodus foetens; *Urophycts flort- danus
Site: stomach
Localities: Alligator Harbor; Dog Island Reef; St. George Island
by
Vola
Lecithochirium parvum Manter, 1947
Synonym: Sterrhurus floridanus Manter 1934 in part
Hosts: *Letostomus xanthurus; * Micro- pogon undulatus; *Paralichthys albigutta
Site: stomach
Locality: Alligator Harbor
>
Lechithochirium microstomum Chandler, 1935
Synonym: — Lecithochirinm Bravo-Hollis, 1956
Hosts: *Angualla rostrata; Trichiurus lep- turus
Site: stomach
Localities: Alligator Harbor; Mud Cove
sinaloense
Lecithochirium texanum (Chandler, 1941) Manter, 1947
Synonym: Sterrhurus texanus Chandler, 1941
Host: *Selene vomer
Site: stomach
Locality: Alligator Harbor
Lecithochirium mecosaccum Manter, 1 947 * * Figure 6
Hosts: *Sciaenops ocellata; Synodus foe- tens
Site: stomach
Locality: Alligator Harbor
The main distinguishing features of Lecithochirtum mecosaccum ate the broad vitelline lobes, the large sinus sac and ejacu- latory vesicle, and a long muscular herma- phroditic duct. The preacetabular pit, de- scribed as indistinct and nonglandular, was not observed in specimens from Synodus foetens but was evident in some of the speci- mens from Sczaenops ocellata. The genital pore is a slit-like opening usually just pos- terior to the pharynx but may be more pos- terior due to contraction of the muscular hermaphroditic duct.
Lecithocladium excisum (Rudolphi, 1819) Luhe, 1901** Synonyms: Lecithocladium excisiforme Cohn, 1903; L. gulosum (Linton, 1899) Looss, 1907; L. cristatum (Rudolphi, 1819)
Looss, 1907; L. crenatum (Molin, 1859) Looss, 1907
Hosts: *Peprilus aleptdotus; Poronotus triacanthus
Site: stomach
|
No. 2 Trematodes of Marine Fishes 47
Figure 1. Genitocotyle cablei, holotype, ventral view. Figure 2. Lepocreadium brevoor- tiae, holotype, ventral view. Figure 3. Opechona gracilis, ventral view. Figure 4. Pseu- doacanthostomum floridensis, holotype, ventral view. Figure 5. Same, tracing of a pho- tograph of Corkum’s specimen showing mainly forebody. Figure 6. Lecithochirium meco- saccum, ventral view, from Synodus foetens.
48 Tulane Studies in Zoology
Localities: Alligator Harbor; St. George Island Deposited specimen: U.S.N.M. No. 60089
Stomachicola sp.
Host: Diplectrum formosum
Site: attached to ovary
Locality: St. George Island Tubulovesicula sp.
Hosts: Cynoscion arenarius; C. nebulosus
Site: beneath ovarian membrane and in
body wall muscles Locality: Alligator Harbor
The worms were found on several occa- sions by the second author. Some contained eggs although the majority were immature. No description of the species will be given at the present since the majority of the worms are not in condition favorable for description.
FAMILY SCLERODISTOMIDAE Dollfus, 1932
Sclerodistomum sphoerotdis Manter, 1947 Host: Chilomycterus schoepfi
Site: stomach
Locality: Alligator Harbor
V. SUMMARY
Forty-eight species of Digenea are re- ported from 43 species of fishes from Apa- lachee Bay, Florida. Three new species are described: Gemnitocotyle cablei, (Opecoe- lidae); Lepocreadium brevoortiae, (Lepo- creadiidae ) and Pseudoacanthostomum floridensis, (Cryptogonimidae). Fourteen new locality records bring to 109 the spe- cies of Digenea known from Tampa Bay and the northern Gulf: 27 species from the Texas coast, 50 from Louisiana, 16 from Mississippi, 31 from Tampa and Boca Ciega Bays, and 48 from Apalachee Bay..
VI. ALPHABETICAL Host-PARASITE LIST
Following each host species is the number, in parentheses, of individuals examined.
Ancylopsetta quadrocellate Gill ocellated flounder (1) Genitocotyle cablei Sterrhurus musculus
Anguilla rostrata (LeSueur), American eel (2) Lecithochirium microstomum Sterrhurus musculus
Bairdiella chrysura (Lacépéde), silver perch (18) Bucephaloides caecorum Tergestia pectinata Opecoeloides fimbriatus
Vol. 12
Stephanostomum interruptum Sterrhurus musculus Brevoortia patronus Goode, largescale menhaden (24) Lepocreadium brevoortiae Lecithaster confusus Parahemiurus merus Caranx crysos (Mitchill), blue runner (5) Bucephalus varicus Tergestia pectinata Ceranx hippos (Linnaeus), Crevalle jack (3) Bucephalus varicus Tergestia pectinata Stephanostomum ditrematis Stephanostomum megacephalum Centropristis melanus Ginsburg, Southern sea bass (10) Aponurus laguncula Sterrhurus musculus Chaetodipterus faber (Broussonet), Atlantic spadefish (9) Multitestis inconstans Aponurus elongatus Chilomycterus schoepfi (Walbaum), striped burrfish (3) Diploproctodaeum plicitum Sclerodistomum sphoeroidis Cynoscion arenarius Ginsburg, sand sea trout (5) Cardicola laruei Pleorchis americanus Stephsnostomum interruptum Tubulovesicula sp. Cynoscion nebulosus (Cuvier), spotted sea trout (21) Cardicola laruei Preorchis americanus Stephanostomum interruptum Paraheminurus merus Tubulovesicula sp. Dasyatis sabina (LeSueur), Atlantic stingray (1) Nagmia floridensis Diplectrum formosum (Linnaeus), sand perch (3) Sterrhurus musculus Stomachicola sp. Galeichthys felis (Linnaeus), sea catfish (16) Pseudoacanthostomum floridensis Lactophrys quadricornis (Linnaeus), cowfish (2) Dermadena lactophrysi Lagocephalus laevigatus (Linnaeus), smooth puffer (1) Aponurus laguncula Legodon rhomboides (Linnaeus), pinfish (29) Steringotrema corpulentum Lepocreadium floridanus Lecithaster confusus Parahemiurus merus Leiostomus xanthurus Lacépéde, spot (8) Homalometron pallidum Lecithochirium parvum Sterrhurus musculus Menticirrhbus americanus (Linnaeus), Southern kingfish (1) Opecoeloides fimbriatus Stephanostomum sentum Sterrhurus musculus Menticirrhus focaliger Ginsburg, minkfish (1) Opecoeloides fimbriatus
Menticirrhus littoralis (Holbrook), Gulf kingfish (1) Opecoeloides fimbriatus
No. 2
Micropogon undulatus (Linnaeus), Atlantic croaker (12) Opecoeloides fimbriatus Lecithochirium parvum Sterrhurus musculus Monacanthus hispidus (Linnaeus), planehead filefish (9) Apocreadium mexicanum Stephanostomum metacercaria Mugil cephalus Linnaeus, striped mullet (4) Schikhobalotrema sp. Mycteroperca bonaci (Poey), black grouper (1) Prosorhynchus atlanticus Ogcocephalus radiatus (Mitchill), polka-dot batfish (2) Sterrhurus musculus Ophidion welshi (Nichols and Breder), crested cusk-eel (5) Sterrhurus musculus Opsanus beta (Goode and Bean), Gulf toadfish (8) Siphodera vinaled ward sii Sterrhurus musculus Orthopristis chrysopterus (Linnaeus), pigfish (12) Sterrhurus musculus Paralichthys albigutta Jordan and Gilbert, Gulf flounder (9) Bucephaloides bennetti Metadena ad globosa Aponurus laguncula Lecithochirium parvum Sterrhurus musculus Peprilus alepidotus (Linnaeus), Southern harvestfish (3) Opechone gracilis Lecithocladium excisum Pomatomus saltatrix (Linnaeus), bluefish (3) Bucephaloides arcuatus Sterrhurus monticelli Poronotus triacanthus (Peck), butterfish (1) Lecithocladium excisum Sciaenops ocellata (Linnaeus), red drum (2) Bucephaloides megacirrus Opecoeloides fimbriatus Lecithochirium mecosaccum Scoliodon terrae-novae (Richardson) Atlantic sharpnose shark (1) Selachohemecus olsoni Scomberomorus maculatus (Mitchill), Spanish mackerel (1) Bucephaloides arcuatus Rhipidocotyle baculum Selene vomer (Linnaeus), lookdown (1) Lecithochirium texanum Strongylura marina (Walbaum), Atlantic needlefish (3) Rhipidocotyle transversale Schikhobalotrema acutum Strongylura notata (Poey), redfin needlefish (2) Rhipidocotyle transversale Syscium papillosum (Linnaeus), dusky flounder (1) Sterrhurus musculus Synodus foetens (Linnaeus), inshore lizardfish (2) Lecithochirium mecosaccum Sterrhurus musculus Trichiurus lepturus Linnaeus, Atlantic cutlassfish (1) Lecithochirium microstomum
Trematodes of Marine Fishes 49
Urophycis floridanus (Bean and Dresel), Southern hake (2)
Sterrhurus musculus
VII. List OF FISHES NEGATIVE FOR TREMATODES
The numbers in parentheses following common names of fishes represent numbers
of individuals examined.
Anchos hepsetus (Linnaeus), striped anchovy (2)
Archosargus probatocephalus (Walbaum), sheepshead (1)
Bagre marinus (Mitchill), gafftopsail catfish (1)
Cyprinodon variegatus Lacépéde, sheepshead minnow (1)
Dorosoma cepedianum (LeSueur), gizzard shad (2)
Echeneis naucrates Linnaeus, sharksucker (1)
Elops saurus Linnaeus, ladyfish (2)
Etropus crossotus Jordan and Gilbert, fringed flounder (1)
Eucinostomus argenteus Baird and Girard, spotfin mojarra (8)
Eucinostomus gule (Quoy and Gaimard), silver jenny (1)
Fundulus similis (Baird and Girard), longnose killifish (9)
Haemulon sciurus (Shaw), blue striped grunt (1)
Larimus fasciatus Holbrook, banded drum (1)
Lutjanus griseus (Linnaeus), gray snapper (1)
Menidia berylline (Cope), tidewater silverside (3)
Mugil curema Valenciennes, white mullet (2)
Paralichthys lethostigma Jordan and Gilbert, Southern flounder (1)
Porichthys porosissimus (Cuvier), Atlantic midshipman (3)
Prionotus tribulus Cuvier, bighead searobin (1)
Trinectes maculatus (Bloch and Schneider), hogchoker (4)
VIII. REFERENCES CITED
CorkuM, K. C. 1959. Some trematode para- sites of fishes from the Mississippi Gulf coast. Proc. Louisiana Acad. Sci. 22: 17- 29.
JOHNSTON, T. H. 1934. Some Australian anaporrhutine trematodes. Trans. Roy. Soc. South Australia. 58: 139-148.
KrusgE, D. N. 1959. Parasites of the com- mercial shrimps, Penaeus aztecus Ives, P. duorarum Burkenroad and P. setiferus (Linnaeus). Tulane Stud. Zool. 7: 123- 144,
LINTON, E. 1940. Trematodes from fishes mainly from the Woods Hole region, Massachusetts. Proc. U. S. Natl. Mus. 88: 1-172.
MANTER, H. W. 1937. A new genus of dis- tomes (Trematoda) with lymphatic ves- sels. Hancock Pac. Exp. 2: 11-22, pl.
SEES ete ts Paes 1947. Digenetic trema- todes of marine fishes of Tortugas, Flori- da. Amer. Midland Nat. 38: 257-416.
origin, waters, and marine life.’ Fishery
50 Tulane Studies n Zoology
Bull. (89) of the U. S. Fish and Wildlife Service. 55: 335-350.
NAHHAS, F. M. and R. M. CABLE 1964. Di- genetic and aspidogastrid trematodes
from marine fishes of Curacao and Ja- maica. Tulane Stud. Zool. 11: 169-228.
RIGGIN, G. T., JR. and A. K. SPARKS 1962. A new gasterostome, Bucephaloides meg- accirrus, from the redfish, Sciaenops ocel- lata. Proc. Helminthol. Soe. Wash. 29: D=29)
SHort, R. B. 19538. dicola laruei n.g., from marine fishes. 309.
A new blood fluke, Car- n.sp. (Aporocotylidae) J. Parasitol. 39: 304-
: _.. 1954. A new blood fluke, Selachohemecus olsoni, n.g., n.sp. (Aporo- cotylidae) from the 'sharp- nosed shark, Scoliodon terrae-novae. Proce. Helminthol. Soc. Wash. 21: 78-82.
Srppiqi, A. and R. M. CABLE 1960. Dige- netic trematodes of marine fishes of Puerto Rico. Sci. Sur. Porto Rico and the Virgin Is. 17: 257-369.
SOGANDARES-BERNAL, F. and R. F. Hutron 1959a. Studies on helminth parasites of
Vol. 12
the coast of Florida I. Digenetie trema- todes of marine fishes from Tampa and Boca Ciega Bays with descriptions of two new species. 1. Bull. Mar. Sci. Gulf Carib. 9: 53-68.
jks Seer Mees aed ase, 1959b. Studies on hel- minth_ parasites from the coast of Flori- da. III. Digenetic trematodes of marine fishes from Tampa and Boca Ciega Bays. J. Parasitol. 45: 337-346. |
: _..... 1959c. Studies on hel='3 minth “parasites from the coast of Flori- da. IV. Digenetic trematodes of marine fishes of Tampa, Boca Ciega Bays, and the Gulf of Mexico. 8. Quart. J. Fla. Aicad. Sev. 2s 259-2138:
s : 1960. The status of some marine species ‘of Lepocreadium Stossich, 1904 (Trematoda: Lepocreadiidae) from the North American Atlantic. Lib. Hom. E. Caballero y C. (Mexico) : 275-283.
SpaRKS, A. K. 1960. Some aspects of the zoogeography of the digenetic trematodes of shallow-water fishes of the Gulf of Mexico. Lib. Hom. E. Caballero y C. (Mexico) : 285-298.
February 23, 1965
TULANE STUDIES IN ZOOLOGY
June 23, 1965
Volume 12, Number 3
HISTOLOGY, DEVELOPMENT, AND INDIVIDUAL VARIATION OF COMPLEX MUROID BACULA
ANDREW A. ARATA, NORMAN C. NEGUS
and MARTHA SAPP DOWNS,! Department of Zoology, Tulane University, New Orleans, Louisiana
CONTENTS PAA ca aT GOS TNAGT GOP TSO SS te ah ger ee see eg eet nd Ow Le Wess ey Sy HeVEERERTALCCANTD METHODS 2..- <8 i I ee oe 52 Ul. RIESTONETES JAIN MDY | DI CLUISSOVN ee PES) PMI S COLO De ae sree ee BO ee SERINE A 2) ib) Development and individual vatiation 55 C. Os clitorides in muroid genera with complex bacula______-______---------------- 61 1b) petleas Oni © alG tin pli CATIONS. x ae. ie ees oes ee St Bae 62 VAG KINIONTGEDGHMEN TS <0 ee te ee ee 63 WAM IMERERETTOES (GVLED = ec 200 ety ee ee 64
ABSTRACT
Bacular development, morphology, and variation was studied in Microtus, On- datra, Sigmodon, Mesocricetus, and Rattus.
Bacular shaft development is essen- tially similar in all forms in which it was studied. A synovial joint is de- scribed as present between the shaft and the distal processes of the bacu- lum. The distal processes were ob- served cssified only in Rattus. In all other forms studied, the cartilage of these processes calcifies when sexual maturity is reached.
1 Present address, Department of Zoolo-
-gy, University of California, Berkeley.
The tctal length of the baculum and the bacular irdex (a summation of the length times the width of the shaft and the preduct cf the length of the median precess times that of a lateral distal process) shows no correlation with known-age of 96 Microtus mon- tanus, but, rather, is related to the to- tal length of the individual. The devel- cpment and absolute form of the bacu- lum presumably is ccntrolled in part by hcrmonal and genetic factors, and chronological age is not as important as physiological age in its development.
Individual variation in the baculum of Microtus montanus is described. The “og clitoridis” of Mesocricetus is not hemolegcus to that of Ondatra as each
EDITORIAL COMMITTEE FOR THIS PAPER: W. RoBert EApIE, Professor of Zoology, Cornell University, Ithaca, New York
EMME? T. Hooper, Professor of Zoology, Museum of Zoology, University of Michi- gan, Ann Arbor, Michigan
W. B. Quay, Associate Professor of Zoology, University of California, Berkeley, Calt- fornia
5)
52 Tulane Studies in Zoology
bone or cartilaginous element is appar- ently homologous to a different part of the complex baculum.
The similarity observed in the devel- opment, histology, and general form of the baculum of Rattus and the cricetids studied herein, suggests that murids and cricetids represent but a _ single family.
I. INTRODUCTION The baculum of many muroid rodents consists of a proximal shaft and three distal processes (Figure 1). It has been recognized for a long time (Gilbert, 1892; Tullberg, 1899), and considered characteristic of the
Imm
Figure 1. Views of the complex baculum of Sigmodon hispidus. The parts of the baculum are: median (mp) and lateral (Ip) distal processes; the spine (sp) and base (b) of the shaft. The views illustrat- ed are: A. lateral, B. dorsal (anti-ure-
thral), C. ventral, D. distal (urethral up- permost), E. proximal (anti-urethral up- permost).
Microtinae, the Cricetini, and certain Neo- tropical or neotropically derived Hesperomy- ini (Cricetinae) and some Muridae (Hooper and Musser, 1964).
Hamilton (1946) described the baculum in numerous Microtinae, as well as in Szg- modon and Oryzomys (Cricetinae), and pointed out the similarity of the structure in such supposedly diverse groups. He also il- lustrated a series of bacula of Microtus penn- sylvanicus and showed the general change in form associated with the assumed age of the
Volsa2
animal. Callery (1951) illustrated series of bacula from a few known-age hamsters (Mesocricetus auratus) produced by inbreed- ing from a single pair of animals. Anderson (1960) figured a growth curve in which length of the bacular shaft of Mzcrotus och- rogaster was plotted against total length of the animal. Elder and Shanks (1962) dis- cussed bacular changes in a limited series of known-age muskrats (Ondatra zibethicus). To our knowledge, no study is available de- scribing changes in the morphology of the baculum in a large series of known-age ant- mals, or considering the histology and changes occurring in the distal processes of this element.
Il. MATERIALS AND METHODS
This report is based on histological obser- vations of the bacula of 6 muroid genera (Table 1), and approximately 50 locally collected hystricomorphs (Myocastor coy- pus). One-hundred and thirty-eight Mzcro- tus montanus (including 97 known-age males and 21 known-age females) used in this study for growth and development data were taken from a laboratory breeding col- ony maintained by one of us (Negus). This colony originated from about 100 Mzcrotus montanus live trapped in Jackson Hole, Wyoming. These animals were maintained
TABLE 1.
Muroid species and number of specimens (in parentheses) examined in this study. Supergeneric groupings follow Simpson (1945).
Superfamily Muroidea Family Cricetidae Subfamily Cricetinae
Tribe Cricetini
Mesocricetus auratus (males 33) females*2) === 5
Tribe Hesperomyini
Sigmodon hispidus
(males 38; females 1)... 4 Peromyscus gossypinus (males 4; females 2). 6
Subfamily Microtinae Tribe Microtini Ondatra zibethicus (males 5;- females 93) == 8 Microtius montanus (males 148; females 33)... 176 Family Muridae Subfamily Murinae Rattus norvegicus (males >> females 2) === 7
Total Specimens Examined 206
No. 3
as pairs in the laboratory, and fed a basic diet of rabbit chow supplemented every few days with lettuce and other greens. A con- stant photoperiod of 18 hours per day was maintained and room temperature was main- tained by air conditioning. No inbreeding was permitted in the colony. Individuals were weaned at 15 days of age, at which time the litters were placed in separate cages, weighed, measured and sexed.
Ill. RESULTS AND DISCUSSION A. Histology
The bacular shaft of all forms we have examined is true bone. It consists of a lat- erally enlarged basal area to which the M. corpus cavernosus attaches and a spine-like distal projection (Figure 1). In all respects, the structure in cricetids is similar to that of Rattus (Ruth, 1934). In small species (i.e. Microtus montanus) and small individ- uals of large forms (2ze., Sigmodon) the shaft is formed by a single haversian system identical to that of the simple baculum of Peromyscus and other Nearctic cricetines (Figure 2). The spine may be composed of several haversian systems in larger forms (e.g. In cross-section the spine
GK, 73
on
of the phallus of Peromyscus gossypinus, illustrating the na- ture of the spine of the baculum (bac).
Figure 2. Cross-section
is circular, oval, or dorso-ventrally flattened. This spine is generally characteristic of the species, but much variation and overlap exists.
Ruth (1934) termed the bony develop- ment of the shaft of Rattws an endoblastemal ossification in which osteogenic cells become active in laying down osteoid substance be-
Muroid Bacula 5) )
fore any marked differentiation of surround- ing tissues can be observed. Although we have not sectioned pre- or neo-natal crice- tids, the bony formation in one-week-old Microtus is similar to that described by Ruth (op. cit.). Diameter increase is by means of an active periosteum. An endosteum is seen in young animals. Maximum shaft length is achieved near breeding age.
Hemopoietic bone marrow and fatty tissue are present in the enlarged basal area of the shaft (Figure 3). Cancellous bone is present in some species. In large individuals of Microtus, and in most individuals of larger forms (e.g. Ondatra) these tissues extend into the medullary cavity of the spine for more than one-half its length.
The several elements of the complex bacu- lum (the shaft and the distal processes) are not of the same origin or histological nature. The distal processes, often referred to as cartilage, ossifying in adults, have not been described histologically. The cartilaginous nature of these processes in young individ- uals has been described by many (Hamilton, 1946; Callery, 1951; Dearden, 1958; Ander- son, 1960; Elder and Shanks, 1962; and others ), but the subsequent “bony” develop- ment often described is usually considered to be typical endochondral ossification. In only one form (Rattus) have we observed this to be the case.
The “ossifications” of the distal processes of the complex cricetid baculum seen are only calcifications of either hyaline or fibro- cartilage. In Mesocricetus (Figure 4), Mi- crotus (Figure 5) and Szgmodon, no true ossifications were found. Only in Rattus (Figure 6) were true ossifications of the distal processes observed. An apparent rea- son for this oversight in previous work is that most studies on bacular morphology employ clearing (in KOH and _ glycerin) and staining (with Alizarin Red) of the whole glans penis in which the bony struc- ture is found. Staining by Alizarin Red is not specific to bone, however, but calcium specific, and differentiation between an ossi- fication and a calcification is not discernible with this technique.
The baculum of Rattus is usually con- sidered to consist of but two osseous portions (Taylor, 1961) and although Hooper (1960) and Hooper and Musser (1964) do consider the glans penis of murines to represent the complex type, the presence of the lateral
54 Tulane Studies in Zoology
wba Sale
aah oil
Figures 3-6. Histological preparations of phalli. 3. Longitudinal section through the phal- lus of Microtus montanus showing hemopoietic tissue present in the enlarged basal area
of the baculum.
4-6. Cross-sections through the distal regions of the phalli showing the
relative sizes and nature of the distal processes. 4. Mesocricetus auratus 5. Microtus mon-
tanus 6. Rattus norvegicus.
distal processes is often overlooked. Whereas these structures are not as free as are those in the cricetids examined by us, their pres- ence is obvious (Figure 6). This fusion of the lateral processes to the median may rep- resent a condition derived from the pattern typically seen in cricetines, as some cricetines show trends in this development (Figure 7).
An unusual histological feature of the bacula studied is the presence of a synovial joint (diarthrosis) between the shaft and the distal processes (Figure 8). We have observed this in Microtus, Ondatra, Sigmo-
don, Mesocricetus, and Rattus. Associated with this joint, but not included in the scope of this report, are tendons and muscles in the soft tissues of the glans penis affecting the movement of the distal elements. The functional morphology and possible adaptive significance of this joint and associated struc- tures will be reported in a later paper.
The distal processes are functionally not separate entities. They develop from car- tilaginous anlagen, as three elements fused, or nearly fused, near the synovial joint. The distal processes exist essentially as a single
r
Figure 7. Cross-section of the phallus of Sigmodon hispidus, slightly distal to the level of the synovial joint, showing the fu- sion of the lateral processes (lp) with the median process (mp) near their junction with the shaft.
Figure 8. Longitudinal section through the phallus of Microtus montanus showing the synovial joint present between the distal and proximal elements of the baculum.
unit, with varying degrees of fusion, culmi- nating in the ankylosed condition seen in adult Rattus.
Different degrees of calcification of the distal processes are seen in different species. It is most complete in the larger forms, or large individuals of smaller species. Large Microtus montanus develop sequelae. Such deposits in this region are visible in Mzcro- tus as anteriorly directed “spurs” (Figure 9). Extra calcification in the distal processes near the region of the synovial joint are evi- dent in the illustrations of adult Ondatra (15 months of age and older) provided by
Muroid Bacula 55
Elder and Shanks (1962). If freedom of the synovial joint is essential in the repro- ductive activities of these forms, continued calcification may mark termination of the reproductive activity on the part of the in- dividual. On the other hand, since most mice have short lives, such a problem may be only of academic interest.
The rod-like baculum of many Nearctic cricetines (e.g. Peromyscus, Neotoma, and others) is capped by a tip of hyaline car- tilage which is adnate with the shaft, but
ventral lateral ventral
172mm
189mm
Figure 9. Excessive calcification in the bacula of large Microtus montanus. The “spurs” in the region of the joint between the shaft and distal processes are calcium deposits. Also note the variation in the shapes and angles of the median and lateral processes of the two bacula illustrated. The total lengths of the animals from which the bacula were obtained are given.
not joined by a synovial joint. This tip is possibly homologous with the medial distal process of the complex bacular form. Though only a small number of such bacula have been examined by us, no calcifications or ossifications in this distal tip have been noted. Hooper (1960) did report that the cartilaginous spine (i.e. tip) is one of four Ototylomys examined was partly osseous (calcified? ).
B. Development and Individual Variation
The shaft of the baculum begins to de- velop in Rattus when the animal is one-day old, and within three days the definitive osseous character of the shaft is established (Ruth, 1934). The youngest Mzcrotus ex- amined by us was 7 days old (72 mm total length), and the osseous shaft of the bacu- lum was 0.9 mm long. No basal enlargement is evident at this stage. By 15 days the basal area is well developed and cancellous. Late
56 Tulane Studies in Zoology
development does not occur in all rodents, however. We have observed prenatal ossi- fications in nutria (Myocastor coypus), a large hystricomorph possessing a long (25 mm), simple, rod-like baculum in the adult. Such late development in the Muroidea per- haps is associated with the general altricial condition of the young.
After the first two weeks the shaft in- creases in length and breadth. The diameter
h) WY Al
Za als 47 210 days 103-105 128 143 177 mm
Figure 10. A selected series of bacula of Microtus montanus arranged by age and total length of the individual from which each was obtained, illustrating the general pattern of growth. Only calcified and true osseous elements are figured.
TOTAL LENGTH LENGTH OF SHAFT
LENGTH OF BACULUM (MM)
0 25 50 75 100
Figure 11.
125 KNOWN AGE (DAYS) Comparison of the known age of 96 Microtus montanus to the length of
Voleal2
of the spine of the shaft increases by active periosteal deposition. Calcifications are not evident in the cartilaginous distal processes until somewhat over one month (with some obvious, expected variation). Until calcifica- tions occur, the cartilaginous limits of the distal processes are not always clearly visible in cleared and stained specimens. Calcifica- tion of the distal processes and expansion of the basal region of the shaft occur rapidly after approximately 35 days of age (Figure 10). All animals examined that were over 40 days of age had some calcification of the distal processes and only one less than 35 days of age demonstrated calcification. This rapid change in the structure of the baculum coincides with other changes of an endocrine nature occurring at the same time. Calcifica- tion of the median process appears to be more rapid (in Microtus) than that of the lateral elements. Generally by 50-60 days calcification of all three processes is under- way.
It is difficult to choose a single measure- ment that satisfactorily demonstrates the in- crease in size of a complex baculum. Figure 11 compares the total length of the bacu- lum (i.e. maximum length of bone and cal-
TOTAL LENGTH OF BACULUM (MM)/AGE (DAYS) LENGTH OF SHAFT (MM)/AGE (DAYS)
N = 96
330 DAYS
150 175 200 225 250
the shafts of the bacula (below horizontal interrupted line) and to the total calcified
length of the baculum (above horizontal interrupted line).
The vertical interrupted line
marks the approximate age at which the latter measurement is obtainable.
TOTAL LENGTH LENGTH OF SHAFT
LENGTH OF BACULUM (MM) w
Muroid Bacula
i,
TOTAL LENGTH OF BACULUM (MM)/TOTAL LENGTH (MM) LENGTH OF SHAFT (MM)/TOTAL LENGTH (MM)
| N= 113
(130 MM)
70 80 90 100 110 120
130
160
180
140 150 170 190
TOTAL LENGTH (MM) Figure 12. Comparison of the total lengths of 113 Microtus montanus to the lengths of
the shafts of bacula
lengths of the bacula (above horizontal interrupted line).
(below horizontal interrupted line) and to the total calcified
The vertical interrupted line
marks the approximate total length at which the latter measurement is obtainable.
cified median distal process), and the length of the shaft only, against the known age of 96 Microtus montanus. Little or no change can be noted in either measurement after 35 days of age. The same bacular measurements are plotted against the total length of the animal (the same known age specimens plus several unknown age individuals) in Figure 12. Although a somewhat closer association is seen, the change is slight and much vari- ation exists. Separation of individuals into age and size groups above 130 mm total length, or above 35 days of age is not pos- sible utilizing either of these parameters (Figures 11 and 12).
Although simple lengths of the bacula do not correlate with known age or total length of the individual, subjective differences in massiveness and rugosity are evident be- tween the bacula of young and old or small and large animals. Such impressions have, of course, been noted before. Hamilton (1946) illustrates 14 bacula of “immature”, “subadult”, and “mature” Microtus pennsyl- vanicus. Elder and Shanks (1962) illustrate similar changes in the bacula of twelve On- datra classified as “juvenile” (5-8 months)
and “adult” (15 months or more) individ- uals. Even though the observations concern- ing bacular form may be suggestive of juve- nile age, Ondatra eight months old may be in breeding condition. The animals in their “juvenile” class (5-8 months old) were trapped in December, and born between April and July. Those born earlier in this period probably were in breeding condition during the latter part of the summer, where- as those born in July had far less chance to enter the breeding population their first year. Not all 5-8 months old Ondatra are juveniles, and if, as we suspect, the develop- ment of the baculum is controlled in part by hormonal factors, chronological age is not as important as physiological age. This consideration, as Elder and Shanks (1962) point out, is often ignored in taxonomic studies.
“It seems unwise for authors comparing various species of the Microtinae to claim that only the middle, or only the lateral digital processes are calcified when only 3-4 specimens of a species have been ex- amined. It also seems likely that disagree- ments as to which of the digital processes
58 Tulane Studies in Zoology
are calcified at all in a genus such as
Phenacomys (Dearden, 1958; Hamilton,
1946), are due to the fact that one man
has examined bacula of juveniles, the
other those of adults.”
Of concern also is the unexplored possi- bility that bacular sizes and forms may dif- fer within a population as the chronological and physiological age composition of the population changes. This could occur dur- ing a season, a year, or in a Classic microtine four year cycle. It would be interesting to compare samples of bacula collected from a single population at different seasons or from year to year.
A number of attempts were made to meas- ure the subjective impression of robustness alluded to above, that we, as well as others, note in viewing series of bacula from mice of different ages and sizes. The most suc- cessful approach is the utilization of an in- dex, obtained by summing the product of the length times the width of the shaft and the product of the length of the median distal process times that of one (the long- est) of the lateral distal processes. Plotting such an index against known age reveals considerable variation following the critical
OD
<
INDEX
7 A 6. B . 5 | = (AB) + (X*Y) * 4 ° . ive . ao . = sie :
0 25 50 75 100
Figure 13. indices.
125 150 KNOWN AGE (DAYS)
Comparison of the known age of 97 Microtus
Volk l2
35 day old point, indicating that, although the index tends to increase with age, the curve is not steep enough to allow separa- tion of animals 50-75 days old from those 225 days old (Figure 13).
Plotting the same indices against total lengths of the animals reveals a closer cor- relation (Figure 14). The index is seen to be closely related to the size of the animal but enough individual variation is present to preclude separation of the 116 animals examined into size groups based on bacular index with any practical degree of prob- ability.
Anderson (1960) notes that in Microtus ochrogaster, “sexual maturity is reached rather abruptly when the total length of most individuals is 140 to 150 millimeters.” This probably corresponds to the 130 mm size we denote as critical in M. montanus. An- derson (op. cit.) also notes that maximum individual variation would occur in animals of this total length (140-150 mm). Our data demonstrate, however, that the greatest variability is evident in old (circa 225 days) and large (above 160 mm) voles (Figures 13 and 14).
A further indication that bacular size is
KNOWN AGE (DAYS) N = 97
330 DAYS
175 200 225 250
montanus to their bacular
Muroid Bacula
a9
INDEX / TOTAL LENGTH (MM)
No. 3 73 ra y x 5 A ua 24
1 = (A-B) + (X-Y)
N= 116
70 80 90 100 110 120
130
180
140 150 160 170 190
TOTAL LENGTH (MM) Figure 14. Comparison of the total lengths of 116 Microtus montanus to their bacular
indices.
dependent more upon total length than upon chronological age of the animal, is sum- marized in data presented in Table 2. Data on animals of two size classes (160-165 mm and 180-189 mm) were selected from the known age M. montanus material and known age and total lengths were compared with the lengths of the bacular shafts and the bacular indices. Although the length of the shaft was essentially the same in both size classes, the bacular index of the larger size group was significantly greater than that of the smaller group of animals (t—3.85 at 27 degrees of freedom; significant at .001 level). Further, the average age of the 160- 165 mm group was 186 days, whereas that of the 180-189 mm group was only 152 days (Table 2). The small number of ani-
mals in the respective classes disallows sig- nificant statistical results, however.
In our laboratory stock of Mzcrotus mon- tanus, both males and females reach sexual maturity at about 5 weeks of age at which time the average total length is approxi- mately 130 mm. That total length of the baculum shows much greater variation after 35 days of age, suggests that physiological factors may influence bacular development This is further implied by closer relation of the bacular index to body length than to age (Figure 12). Apparently, individual dif- ferences in physiology and genetics may ac- count for the greater variability in bacular size once sexual maturity is reached. Per- haps the gonadotropic hormones of the adenohypophysis or the gonadal hormones
TABLE 2.
Comparison of the length of the shaft of the baculum and the bacular index (see text for explanation) in two size classes of adult Microtus montanus.
Size Class Number of Number of Length of (Totallength of individuals known-age the shaft of Bacular Index Age (Days) the individual) in size class individuals the baculum 2.3-2.9 mm 3.1-5.5 79-243 160-165 mm 20 13 (xa 1225) (x = 4.6) (x — 186) 2.3-3.0 mm 4.4-7.2 105-172 180-189 mm 9 4 (x= 236) (xa — 5.4) (xX = 152)
60 Tulane Studies in Zoology
may exert some influence on bacular de- velopment. The general body size attained by an individual is regulated largely by genetic factors, but individual variations in size within a species may well be based more on physiological differences. Thus, an in- dividual possessing a more active (or larger ) anterior pituitary (producing more somato- tropin) may grow faster and larger than another of its own species. Similarly, a more active pituitary might also release greater amounts of gonadotropins and release of more adrenal androgens may influence the possible relationship of bacular growth to sexual maturity and total length (as a meas- ure of size of the individual) in Mzcrotus. Presumably, elucidation of endocrine rela- tionships to bacular development can be readily accomplished for many mammals by experimental procedures in the laboratory using known-age animals.
It is perhaps surprising that endocrine ef- fects on such a taxonomically important ele- ment as the baculum have not been noted by mammalogists before, as they are well recorded in the literature. A response in baculum size (associated with general mas- sive development of all parts of the male reproductive tract) in Rattus to androgens has been recorded by Korenchevsky et al. (1932) and Thyberg and Lyons (1948).
Howard (1959) referring to gonadectom- ized mice (Mws) states: “not only is there an increase in lengths of the bone (1.e. bacu- lum) with DHA (dehydroepiandrosterone ) , but the changes in shape and thickness are striking.” A similar response is produced by administration of 11-hydroxy-androstene- dione (an adrenal androgen) to gonadectom- ized mice (Howard, op. cit.).
These data suggest that chronological age cannot be ascertained in Microtws by meas- urements of a number of parameters of the baculum. We suspect that the same is true for other rodents with the complex type of baculum. Total bacular size (as indicated by the index herein employed) appears to be possibly a function of hormonal activity and physiological, rather than chronological, age.
Other than differences directly attributable to size, considerable individual variation was noted in the bacula of M. montanus. Figure 15 illustrates a series of bacula demonstrat- ing the extremes of variability observed in the 117 males studied. The base of the shaft
Vol. 12
is usually a crudely shaped diamond without a basal notch. In some (Figure 15E), a notch is present. In others the shape of the base varies from roughly triangular (Figure 15D) to oblong (Figure 15H), often with an ir- regular, rugose proximal edge (Figure 15G). The spine of the shaft is more constant in form than the base, though occasional medial or terminal swellings are evident (Figures ISB and 151). The “spurs” or sequelae, mentioned above, are often present near the synovial joint associating shaft and distal processes (Figure 15B and 15J). These latter elements are highly variable. The cal- cified portion of the median process may be simple rod-like (Figure 15C, 1SE, and 15G) or may be expanded near its base (Figure ISA, I5F, 15H, and 15J). Although this expansion is generally associated with greater age or total length of the individual, excep- tions were noted.
205 89 days 17O) | We \ 189 \ 140 mm PA 220 days 175 163 161. mm yb j be Wy 167 days 180 162 189 mm Figure 15. Ten bacula of Microtus mon- tanus illustrating individual variation.
Ages and total lengths of the individuals from which the bacula were taken are given below the figures.
No. 3
The lateral distal processes vary greatly between individuals and sometimes between members of the same pair. Calcification, even in large, adult animals, may be com- plete or incomplete, and may, in each proc- ess, result from one or occasionally two, centers of calcification (Figure 15C). If fully calcified, these processes may curve inward (Figure 15A and 15G), or remain straight (Figure 15D and 15E). The tips occasionally curve outward. Viewed laterally the lateral processes vary in their relation to the median process and the shaft, some- times lying in the same plane as the shaft or declinating by as much as a 45° angle (Figure 9).
In the Microtus studied, the lateral proc- esses are the last to calcify and occasionally they may not do so. In large microtines (e.g.Ondatra) these elements are large and usually well calcified. Pztymys, one of the smaller microtines, is often characterized by the poor development of these processes. Possibly the different degrees of calcification seen in a group such as the microtines may be more a function of the average or maxi- mum size obtained by the form than a morphological characteristic, per se.
Muroid Bacula 61
C. Os Clitorides in Muroid Genera with Complex Bacula
As homologs of the penis, clitoral ele- ments are of interest as they often demon- strate what may be interpreted as either rudimentary or reduced conditions of the male structures. In some rodents, especially the sciurids, the os clitoridis is a small, clearly homologous, version of the baculum (Layne, 1954). This is not the case in the muroids examined.
In muroids the clitoris forms a small rep- lica of the penis. The urethra is enclosed within the clitoris in Mesocricetus, Ondatra (Figures 16 and 17) and Microtus. Distally the clitoris terminates in three lobes of tis- sue, homologous with the anlagen of the three distal processes of the baculum. Car- tilaginous tissue is present in these lobes in the genera examined. In Ondatra the fibro- cartilage of the median lobe calcifies in large individuals (Figures 17 and 18A), and although we have not observed calcifications in the lateral processes, they possibly may occur in some individuals. The only other microtines in which the os clitoridis has been reported are Microtus californicus and M. longicaudus (Ziegler, 1961). The illus-
Figure 16. Cross-section of the clitoris of Mesocricetus auratus showing the true bony
nature of the os clitoridis (os).
Figure 17.
Cross-section of the clitoris of Ondatra
zibethicus, showing the homologs of the lateral processes of the baculum (lp), and the median process with a calcified fibro-cartilage “os clitoridis” (os). The urethra (ur)
is visible in both Figures 16 and 17.
62 Tulane Studies in Zoology
trations of these specimens suggest that they are of the same type as that of Ondatra. We have examined 21 female Miécrotus montanus ranging in total length from 145- 166 mm, and in age from 212-245 days, but have observed no calcification following Alizarin Red staining. Fibro-cartilage is present in the median lobe, however, and under favorable conditions might calcify. Ziegler (1961) suggests that the occurrence of the os clitoridis in Mzcrotus may not be associated with age, as it is found in both young and old animals.
The os clitoridis of Mesocricetus is quite different from that of the microtines. In Mesocricetus the element is located more proximally and has a more definitive shape (Callery, 1951). Sectioning reveals that this is true bone (Figure 16), histologically iden- tical to the shaft of the baculum. Its proxi- mal location in the clitoris confirms this homology (Figure 18B). No calcifications were noted in the three large, loosely car- tilaginous lobes of tissue present distally in Mesocricetus.
The “os clitoridis” of Mesocricetus is not homologous to those of Ondatra and Micro- tus, as each is homologous to a different part of the complex baculum. The “os cli- toridis” of Mesocricetus is the only one ob- served that can properly be termed a bony element.
D. Taxonomic Implications
The continuing use of the baculum and other phallic structures in mammalian, espe- cially muroid, systematics, suggests the de- sirability of much more information on the development, individual variability, micro- structure, and physiological and chronolog- ical relationships of these elements before sound taxonomic interpretations can be based on them.
From the data presented above, bacular structures Obviously are subject, at least at the population and infraspecific levels, to considerable variability. Such observable dif- ferences may be dependent upon a plethora of variables, including the endocrine state of the individual, chronological age, genetic background, etc.
The degree of such variability, and the importance of the endocrine state, as well as the nature of the calcifications observed in the distal processes in this study, cast doubt on the utility of minor differences in
Vol. 12
ventral lateral
ventral lateral
Figure 18. Clitorides of two cricetids, Onda- tra zibethicus (A) and Mesocricetus aura- tus (B), illustrated in ventral (urethral) and lateral views. The “os clitoridis” of each is stippled.
form and size of the complex baculum in systematic studies at the lower taxonomic levels in those rodents in which it occurs. The source of specimens employed in such studies also seems to be of considerable im- portance. Unfortunately, many specimens available in collections, and often used in morphological and systematic studies, have been aged on such criteria as the condition of the pelage and/or the size of the testes and epididymides. Whereas such criteria may determine “ecologically adult” individ- uals (i.e. individuals functioning as sexually mature entities in a population), they pro- vide no reliable information on the true chronological or physiological age of the
:
No. 3
individual. Since only a small percentage of rodents seem to achieve full morphologi- cal adulthood under natural conditions, laboratory colonies of known age animals can perhaps provide better material for com- parative morphological studies of male re- productive organs and systematic studies based on these elements than can be obtained in the field.
This does not mean to imply that observ- able differences do not exist between the bacula of different muroid rodents, particu- larly at, and above, the generic level. At these levels gross differences in proportions and/or dimensions can generally be sub- stantiated as has been shown by Hooper (1960 and other papers) and Hooper and Musser (1964). Even at these levels, how- ever, it would seem imperative to under- stand something of the development of the baculum, or at least to select bacula from individuals of large size as these may repre- sent the maximum, and therefore character- istic development of the form involved, reducing the variability caused by the en- docrine state, diet, and other factors.
Above the generic level basic anatomical patterns of bacular development and form, as well as association with other structures of the glans penes should be similar within phylogenetically related groups. Within the Rodentia such information is currently only available within the myomorphs, and the similarity of the baculum or the complete glans penis in diversely classified muroids has been noted for some time. Hamilton (1946) compared Oryzomys and Sigmodon to the microtines. Hooper and Musser (1964) in a study of the glans penes, con- sidered cricetids and murids to represent a single family (Muridae). Arata (1964), studying the male accessory reproductive glands, demonstrated that a basic pattern existed in murids and cricetids, and sug- gested that only one family was represented. Hershkovitz (1962) discounted the com- monly accepted differences in dental pattern between the murids and cricetids and recog- nized only a single family (Muridae), pre- ferring the evidence afforded by the phallus.
The similarity of bacular form in Rattus and the cricetids examined in this study supports the thesis that murids and cricetids represent but a single family. The develop- ment of the baculum of Rattus described by Ruth (1934), and the presence of a movable
Muroid Bacula 63
joint between proximal and distal elements of the baculum of Rattus and the cricetids noted in this report suggests that basic homologous morphological forms are repre- sented.
Although all cricetids examined by us have calcified fibro-cartilage distal elements as contrasted to the bony distal processes of Rattus, far too many muroids remain un- examined, and little systematic significance can be placed on this difference at this time.
The fusion of the distal elements seen in Rattus is greater than that observed in the cricetids, but is probably derived from the basic cricetid pattern. Hooper and Hart (1962) note similar trends in microtines, and Hooper and Musser (1964) point out that this trend may have occurred several times, and is evident in microtines, murines, South American cricetines and Old World cricetines, producing secondarily simple penes, derived from an ancestral complex stock. Bittera (1918) previously suggested that such reductions were secondary. The evidence produced by a study of the male accessory reproductive glands (Arata, 1964) also suggests that certain glandular comple- ments, usually present along with the com- plex baculum occurs in muroids (including cricetines, microtines, and murines), and is variously reduced in different subgroups.
Thus, the data presented above reinforce the importance of the baculum and associated phallic structures in studies of muroid ro- dents at the generic level and above, and suggest caution concerning the utilization of the baculum alone at specific and subspecific levels in rodents in which the complex type is present.
IV. ACKNOWLEDGMENTS
The authors thank Mr. J. Howard Hutch- ison for drawing Figure 1 and Mr. Larry H. Ogren for aid in collecting specimens of Ondatra and Myocastor used in this study.
The senior author carried out part of this work under the auspecies of the American Cancer Society (Grant No. IN 24-E) and the National Science Foundation (GB 2458). Mrs. Downs (Martha C. Sapp) participated in this study while a recipient of a National Science Foundation Undergraduate Research Fellowship at Tulane University (Newcomb College). Availability of the Mzcrotus mon- tanus utilized in this study was made possible
64
by support from the National Science Foun- dation (188926), U. S. Atomic Energy Com- mission (AT-40-1-1831) and the New Or- leans Cancer Association.
V. REFERENCES CITED
ANDERSON, SYDNEY 1960. The baculum in microtine rodents. Univ. Kans. Publ. Mus) Nat: Hist. 112): 1822216:
ARATA, ANDREW A. 1964. The male acces- sory reproductive glands of muroid ro- dents. Bull. Florida State Mus., Biol. Sci. 9: 1-42.
BITTERA, JULIUS 1918. FHiniges iiber die mdnnlichen Kopulations-organe der Muri- den und deren systematische Bedeutung. Zool. Jahrb., Abl. Systematik. 41: 399- 418.
CALLERY, R. 1951. Development of the os genitalia in the golden hamster, Meso- cricetus (Cricetus) auratus. J. Mammal. 32: 204-207.
DEARDEN, L. C. 1958. The baculum in La- gurus and related microtines. J. Mam- mal. 39: 541-553.
ELDER, W. H. and C. E. SHANKS 1962. Age changes in tooth wear and morphology of the baculum of muskrats. J. Mammal. 43: 144-150.
GILBERT, T. H. 1892. Das os priapi der Saugethiere. Morph. Jahrb. 18: 805-831.
HAMILTON, W. J., JR. 1946. A study of the baculum in some North American Micro- tinae. J. Mammal. 27: 378-386.
HERSHKOVITZ, PHILIP 1962. Evolution of neotropical cricetine rodents (Muridae) with special reference to the phyllotine group. Fieldiana: Zoology. 46: 1-524.
Hooper, EMMET T. 1960. The glans penis in Neotoma (Rodentia) and allied genera. Occ. Pap. Mus. Zool., Univ. Mich. No. GilSieem=2 02
Hooper, EMMETT T. and B. S. Hart 1962.
Tulane Studies in Zoology
Vol. 12
A synopsis of North American microtine rodents. Misc. Publ., Mus. Zool., U. Mich. No. 120: 1-67.
HooPpeR, EMMET T. and Guy G. MUSSER 1964. The glans penis in Neotropical cri- cetines (Family Muridae) with comments on classification of muroid rodents. Misc. Publ., Mus. Zool., U. Mich. No. 123: 1-57.
HOWARD, EVELYN 1959. A complementary action of corticosterone and dehydroepi- androsterone on the mouse adrenal, with observations on the reactivity of repro- ductive tract structures to dehydroepian- drosterone and 11-hydroxy-androstenedi- one. Hndocronol. 65: 785-801.
KORENCHEVSKY, V., M. DENNISON and A. KOHN-SPEYER 1932. The rat unit of tes- ticular hormone. J. Biochem. 26: 2097- 2107.
LAYNE, JAMES N. 1954. The os clitoridis of some North American Sciuridae. J. Mam- mal. 35: 357-366.
RuTH, E. B. 1934. The os priapi: a study
in bone development. Anat. Ree. 60: 231-249.
SIMPSON, GEORGE G. 1945. Principles of classification and a classification of mammals. Bull. Amer. Mus. Nat. Hist. 88: 1-350.
TAYLOR, J. MARY 1961. Reproductive biolo- gy of the Australian bush rat, Rattus assimilis. U. Calif. Pub. Zool. 60(1): 1-66.
THYBURG, W. G., and W. R. Lyons 1948. Androgen-induced growth of the os pe- nis of hypophysectomized-gonadectomized rats. Proc. Soc. Exp. Biol. and Med. 69: 158-161.
TULLBERG, TYCHO 1899. Ueber das System der Nagethiere, eine Phylogenetsche Studie. Nov. Acta. Reg. Soc. Upsala, ser. 3, vol. 18: 329-541.
ZIEGLER, ALAN C. 1961. clitoridis in Microtus. 101-103.
Occurrence of os J. Mammal. 42:
ETHEOSTOMA DITREMA, A NEW DARTER OF THE SUBGENUS OLIGOCEPHALUS (PERCIDAE) FROM SPRINGS OF THE ALABAMA RIVER BASIN IN ALABAMA AND GEORGIA
JOHN S. RAMSEY
and
ROYAL D. SUTTKUS, Department of Zoology, Tulane University,
New Orleans, Louisiana 70118
ABSTRACT
Etheostoma (Oligocephalus) ditrema is described from 183 specimens from three localities in the upper Coosa-Ala- bama River basin. It is restricted in habitat to springs and spring-fed ponds above the fall line. It is a small, sexu- ally dimorphic species most closely re- lated to but sharply differentiated from E. swaini of the eastern Gulf Coast- al Plain. Infraspecific variation is marked. E. ditrema is unusual among percids in typically possessing two cor- onal pores, which, when considered with other characters, suggests that it is a paedomorphic species of the H. aspri- gene species group.
The subgenus Oligocephalus is the most complex and speciose group of those com- prising the North American darter genus Etheostoma. The members of the group were delimited by Bailey and Gosline (1955), who recognized 19 nominal species. Strawn and Hubbs (1956) recognized Etheostoma lepidum (Baird and Girard) as a species distinct from E. grahami (Girard). Yerger (1960) resurrected E. okaloosae (Fowler ) from the synonymy of E. swaini (Jordan), and included it in the subgenus Véllora. Etheostoma spilotum Gilbert was reduced to a subspecies of E. sagitta (Jordan and Swain) by Kuehne and Bailey (1961). Distler and Metcalf (1962) described E. pallididorsum, which may prove to be a subspecies of E. cragimt Gilbert. With the definition of the subgenus Oligocephalus and the redescrip-
tion of E. hopkinsi (Fowler) by Bailey and Richards (1963), the number of recognized nominal species in the group was brought tome
Etheostoma ditrema was first collected by Jordan (1876) in millponds of the region of Rome, Floyd Co., Georgia. However, he misidentified his specimens as Boleichthys elegans Girard, which is probably a synonym of E. grahami, a species of southwestern United States and northeastern Mexico.
We discovered the new darter during the spring of 1962, in a spring tributary to the Coosa-Alabama river system in northwestern Georgia. Later another spring locality in northeastern Alabama was brought to our attention.
We acknowledge gratefully the assistance of the following. Clyde D. Barbour, Wil- liam T. Mason, Jamie E. Thomerson, and members of the Tulane University Summer Program in Environmental Biology for 1964 aided in the collection of material. Richard D. Caldwell and W. Mike Howell (Univer- sity of Alabama) apprised us of the existence of the Alabama population of ditrema and have given information on their collecting efforts in springs of northeastern Alabama. Dr. Herbert T. Boschung loaned material from the University of Alabama Ichthyology Collection (UAIC). Dr. Bruce B. Collette discovered and notified us of a single speci- men of ditrema remaining from Jordan’s
EDITORIAL COMMITTEE FOR THIS PAPER:
BRUCE B. COLLETTE, Acting Director, Ichthyological Laboratory, U. S. National Mu-
seum, Washington, D. C.
LESLIE W. KNAPP, Supervisor for Fishes, Oceanographic Sorting Center, U. S. Na-
tional Museum, Washington, D. C.
GEORGE A. Moore, Professor of Zoology, Oklahoma State University, Stillwater,
Oklahoma
66 Tulane Studies in Zoology
collection in the region of Rome, Georgia. He allowed us to examine this specimen while he had it on loan from the Academy of Natural Sciences of Philadelphia (ANSP). Miss Winona H. Welch (De Pauw Univer- sity) identified aquatic mosses from the type locality. Assistance in field work was made through National Institutes of Health grants WP-00082-04, 05 and 3-T1-ES-27- 01S1, 02S1, and National Science Founda- tion NSF G-23598 to Suttkus, and NSF G-17005 to Ramsey through the Highlands Biological Station, Inc., North Carolina.
Etheostoma (Oligocephalus) ditrema new species Coldwater darter ( Figs. 1-3 )
Boleichthys elegans—Jordan, 1876: 309 (misidentification ).
Material—Description is based on 133 specimens from three localities in the Coosa- Alabama river drainage. The holotype, TU 35703, an adult male 33.9 mm in standard length, was collected in a spring flowing into a small tributary to Mills Creek, tribu- tary to Chattooga River, 4.3 airline miles due west of Lyerly, Chattooga Co., Georgia (0.2 miles ENE of the Alabama boundary ), on the Broomtown (Ala.)-Foster’s Store- Lyerly road (T7S, R11E, Section 28) on 18 July 1962. Taken with the holotype were 21 paratopotypes (TU 29153, 15-35 mm s.l.). Other paratopotypes were taken 19 April 1962 (TU 26086, 8: 24-31), 30 May 1962 (TU 27566, 9: 18-34), 1 June 1964 (TU 32762, 34: 19-42), and 23 June 1964 (TU 32981, 43: 20-39). Five para- topotypes from TU 32981 have been dis- tributed to each of the following institu- tions: USNM 198607, United States Na- tional Museum; MCZ 43123, Museum of Comparative Zoology, Harvard University; ANSP 101231, Academy of Natural Sciences of Philadelphia; UMMZ 187501, University of Michigan, Museum of Zoology; CU 47872, Cornell University; SU 62401, Stan- ford University.
A paratype (ANSP 20649, 1: 23) was collected during the summer of 1876 from a millpond (Etowah River drainage) near Rome, Floyd, Co., Georgia.
308-
Specimens from a third population, not designated as type material, were captured in Coldwater Creek, tributary to Choccolocco
Vole
Creek, immediately below Coldwater Spring (T16S, R7E, Section 29), at Coldwater, 5.7 miles W of Oxford, Calhoun Co., Alabama, about 500 yards north of U. S. Highway 78, on 28 January 1964 (UAIC 1138, 1: 38), 1 June 1964 (TU 32746, 9: 26-41), and 31 August 1964 (TU 34400, 6: 20-32).
Several series of Etheostoma swaini from the Alabama River drainage were used for comparison with ditrema. These include TU 9497 (2: 43-55), Ala., Montgomery Co., creek 12.6 miles east of Montgomery, Highway 80; TU 34016 (5: 20-38), Ala., Clarke Co., Sand Hill Creek 1.1 miles west of Choctaw Bluff: TU 35176 (472 22-43) Ala., Dallas Co., Pine Flat Creek 6 miles south of Selma. The problem of geographic variation in swaimt and in the asprigene comp!ex is being reported elsewhere.
Counts and measurements were made fol- lowing Hubbs and Lagler (1958), except transpelvic width, the distance between the outer bases of the pelvic spines when held parallel (Bailey and Richards, 1963). The cephalic lateralis canals were analyzed fol- lowing Hubbs and Cannon (1935).
Diagnosts—A_ small, moderately robust species of the subgenus Oligocephalus. Lat- eral line moderately arched and incomplete, pored lateral-line series terminating between the level of the posterior base of the spinous dorsal fin and posterior soft dorsal base; total lateral-line scales 41 to 54, pored scales 19 to 35, unpored scales 13 to 30. Coronal canal incomplete, usually two coronal pores; infraorbital canal complete; supratemporal canal usually interrupted. Branchiostegal membranes overlapping anteriorly. Nape naked to completely scaled; breast usually scaled, rarely naked; prepectoral region, cheeks, opercles, and posterolateral corners of top of head scaled. Dorsal fin-rays VIII to XII—9 to 12; anal I, 6 to 8; pectoral 11 to 13. Nuptial tubercles absent. Vertebrae 35 to 37. Breeding male dark brown with orange pigment on belly and lower caudal peduncle; female indistinctly mottled with dark brown. Submarginal orange band pres- ent in spinous dorsal fin of both sexes. Humeral dark spot absent. Three dark blotches (rarely somewhat ocellate) in a vertical series at caudal fin base.
Description—Etheostoma ditrema is a dwarfed species of the subgenus Ol/gocepha- lus, The largest specimen available is a
PF aw —_
~ SBE ele CEL EPR Ga
ge ee
Figures 1-3. Etheostoma ditrema, new species. 1.
A New Darter 67
(Upper) TU 32762, male paratopo-
type, 39.0 mm standard length. 2. (Middle) TU 32762, female paratopotype, 31.9 mm.
3. (Lower) TU 32746, female, Coldwater Creek, 40.7 mm. Photographs by C.
bour.
male 42.1 mm in standard length, the larg- est female, 40.7 mm. Adulthood is appar- ently reached when a standard length of 25 mm is attained. The body is moderately robust but somewhat compressed. The body is widest just behind the head, and deepest at the level of the pelvic fin insertion, ex- cept in gravid females. There is a moderate nuchal hump in about half of adult males and in a third of adult females. The caudal peduncle is moderately slender. These and
D. Bar-
other proportional measurements are listed in Table 1.
The head is of moderate length, about 30 percent of standard length. The snout is gently to abruptly decurved and short, its length usually less than orbit length. The upper and lower profiles of the snout meet at an angle of 55° to 85°. The projected angle formed by the upper and lower head surfaces behind the eye ranges from 19° to 30°. The frenum is always well-developed,
68 Tulane Studies in Zoology Vol. 12 TABLE 1. Measurements of Etheostoma ditrema in thousandths of standard length TU 26086 TU 26086 TU 357038 27566, 29153 29153 Catalog Number Holotype Paratypes Paratypes Number of specimens 1 9 10 Sex 3 3 g Range x1 Range x
Standard length (mm) 33.9 24.9-33.7 (30.4) 26.7-35.3 (31.3) Predorsal length 348 346-367 (353) 358-371 (358) Anal origin to snout 644 619-656 (641) 634-668 (650) Body depth 209 190-208 (199) 190-228 (206) Distance from soft dorsal
origin to anal origin 180 157-175 (169) 149-176 (161) Body width 142 121-138 (130) 124-153 (139) Caudal peduncle length 233 227-265 (244) 227-272 (245) Caudal peduncle depth 106 97-109 (103) 90-111 (100) Head length 307 294-312 (320) 280-317 (300) Head depth 174 165-177 (fas) 159-180 (166) Head width 136 125-145 (si) 129-149 (CLB37()) Lower jaw symphysis to
juncture of gill membranes IPA 115-149 (13:2) 126-152 (136) Pelvic insertion to juncture
of gill membranes 192 167-192 (180) 180-198 (185) Orbit length 74 76-89 (80) 72-90 (80) Snout length Pal 54-72 (66) 59-75 (65) Upper jaw length 86 80-96 (87) 82-95 (87) Width of gape 74 72-85 (79) 70-83 (76) Interorbital width, least fleshy 50 48-64 (55) 31-54 (50) Spinous dorsal base 274 260-289 (276) 252-288 (269) Longest dorsal spine 97 85-112 (99) 67-99 (85) Soft dorsal base ales 158-197 (LYK) 142-184 (166) Longest dorsal soft ray 174 131-159 (143) 127-153 (139) Soft dorsal, depressed length 254 218-273 (252) 221-257 (236) Longest anal soft ray 142 LAGE 5A (140) 113-138 (128) Anal fin base 124 94-136 (ala) 96-115 (107) First anal spine 86 69-95 (84) 65-87 (74) Anal, depressed length 200 205-230 (216) 192-214 (199) Longest pectoral ray 200 187-245 (207) 158-216 (191) Pelvic fin length 209 186-223 (265) 173-194 (185) Pelvic fin base 32 382-39 (35) 33-39 (36) Interpelvic distance 15) 10-16 (13) 10-19 (14) Transpelvie width f(a 61-67 (65) 62-72 (66) Caudal length 206 190-232 (209) 187-216 (203)
1 Holotype included in mean for males.
although frequently narrow. The mouth is terminal or slightly subterminal, and_pro- jects posteriorly and downward to or slightly beyond the anterior edge of the eye. The prevomer and palatine bones bear teeth. The upper surface of the eye in lateral aspect is even with the top of the head. The gill membranes are usually separate and over- lapping anteriorly, occasionally very slightly conjoined. There are six branchiostegal rays on each side.
The lateral line is incomplete, and is ele- vated and arched anteriorly, beginning the downward arc at about the level of the
spinous dorsal origin. The pored lateral line terminates at the level of a point between the posterior spinous dorsal and_ posterior soft dorsal bases.
The infraorbital canal is usually complete (interrupted on one side in one of 22 type specimens and in two of 16 specimens from the Choccolocco Creek drainage; interrupted on both sides in one specimen from the Choccolocco locality, pores 24-5 - 5-4-2). In- fraorbital pores usually number 8 (5 to 9). The preoperculomandibular canal is typically complete, usually with 10 pores (rarely 8 or 11, frequently 9). The supratemporal
No. 3 A New canal is usually interrupted, each branch having 2 pores (Table 5). The lateral canal normally has 5 pores.
An unusual diagnostic feature is the pos- session of two well defined coronal pores in most specimens (Table 5), which results from the non-fusion of the two coronal canals branching mesially from the supra- orbital canals. In all other species of Oligo- cephalus, and in other percid subgenera, these branches fuse to form a_ backward- projecting tube terminating at the coronal pore. In E. ditrema the two coronal branches emerge side-by-side just posterior to a line between the upper orbital rims. The two pores may fuse as one, but there is rarely a tube directed caudad to the pore. There are in addition four pores in the supraorbital canal, although infrequently one interorbital pore is absent. Rarely, one of the coronal branches has failed to develop.
Scale row counts (Tables 2 and 3): total lateral-line scales number 41 to 54 (usually 44 to 50), pored lateral-line scales 19 to 35
Darter 69
(usually 22 to 32); unpored lateral-line scales 13 to 30 (usually 16 to 26); trans- verse body scales (from soft dorsal origin posteroventrally to anal fin base) 11 to 14 (usually 12 or 13); scales above lateral line 3 to 5 (usually 4); scales below lateral line 6 to 9 (usually 7 or 8); caudal peduncle scales 17 to 22 (usually 19 to 21). Squamation: The opercles, cheeks, belly, and prepectoral region are wholly invested with exposed ctenoid scales. There are a few scales embedded on the head just above and anterior to the junction of the supra- temporal and lateral canals. The breast is naked anteriorly. The posterior breast is usually scaled, although some infraspecific variation exists. The type material from the Chattooga and Etowah drainages in Georgia usually has exposed ctenoid breast scales. Occasionally the scales are embedded, or a narrow median strip is naked, but the breast is never entirely scaleless. Of the 16 speci- mens available from Coldwater Spring, only one has exposed ctenoid breast scales, 10
TABLE 2.
Distribution of scale row counts in Etheostoma ditrema and E. swaini.
Value for
holotype of ditrema in boldface
Species and drainage
Total lateral-line scales
39 40 41 42 438 44 45 46 47 48 49 50 51 52 53 54 N
ditrema
Chattooga Le Lees Or iG 22S el Geena — ne OO Etowah 1y— jl 1 Choccolocco a 3 4 a BY 2 | 1115) swaini Alabama 1 4 3 2 Se LO 1 52a 44 Caudal peduncle Soft dorsal origin seales to anal base 17 28 19 20 21 22 N SLD ott 3 lA Ny ditrema Chattooga 3) Ads sian eo) ao 108 2 Gon 40. e209 Etowah 1 1 1 1 Choccolocco 1 i 8 3 1 14 14 1 155 swaini Alabama 1 4S ala lhe lO) 3) 44 i ae lel ell Seales above Scales below lateral line lateral line BE i De IN Grae Oso ll OvaeN ditrema Chattooga 2) ie) WC 76 Br x0) Bil 7 70 Etowah 1 il 1 1 Choccolocco 14 1 a LS) Oe Lbs swaini Alabama 3) By ty Il All 5) PQ) aly Bal!
'.! Both sides of single specimen used: r
= richt, |] = left
70
Tulane Studies in Zoology
Vol. 12
TABLE 3 (continued on opposite page) Lateral line scales in Etheostoma ditrema and EF. swaini. Value for holotype in boldface.
Species and drainage 19 20 21
ditrema Chattooga 3 2 2 Etowah Choccolocco 1 1
swaini Alabama
Pored lateral-line scales
22 23 24 25 26 27 28 29
3 8 11 15 12 12 11 1 2 1 — 2 3 3
Unpored lateral-line scales
4 5 6 7 8
9 10 iil 12 13 14 15 16
ditrema Chattooga Etowah Choccolocco
swaint Alabama 1 3 9 10 10
have scattered, embedded ctenoid scales, and 5 have the breast completely naked.
Nape squamation is variable (Table 6). Specimens from Coldwater Spring tend to have the nape more fully scaled than in type specimens. The notation used for the de- gree of nape squamation in Table 6 was derived from a relative scale. zero signifies that at least the median por- tion of the nape from the spinous dorsal origin to the occiput is naked; I through II represent successive increases in posterior nape squamation; IV, nape wholly scaled but scales embedded at least anteriorly; V, nape completely invested with exposed scales.
Fins (measurements in Table 1): The spinous dorsal is composed of 8 to 12 slender spines. Many specimens have small postapical fleshy enlargements at the spine tips similar to those in other species of Oligocephalus. The fin is low; the length of the longest spine (located at the fin cen- ter) is about two-fifths to one-half the length of the fin base, and can be stepped into head length two and one-half to three times. The fin border in both sexes usually forms a gentle arc rearward to the dorsum (not subquadrate in outline, as in E. swainz). The soft dorsal fin is usually well separated from the spinous dorsal (as in Fig. 2). There is typically a much broader hiatus be- tween the fins in the Choccolocco population (Fig. 3). Though low, the soft dorsal is higher than the spinous dorsal. Dorsal soft rays number 9 to 12. Total dorsal rays range
A value of
from 18 to 23. The Choccolocco population has fewer dorsal rays (Table 4), which probably is correlated with the greater dor- sal fin separation.
The anal fin is also small. There are usu- ally two spines (one specimen out of 133 has a single spine, and two have three spines). The second spine is usually more slender than the first. The second spine in the Choccolocco population is usually stiff, but is typically very slender and flexible in specimens from Georgia. Anal soft rays number 6 to 8 (usually 7).
There are 11 to 14 (usually 12 or 13) branched caudal rays. The posterior edge of the caudal fin is usually truncate, frequently slightly emarginate or convex. The pectoral fins are short and rounded, the longest ray about two-thirds of head length. Left pec- toral rays number 11 to 13 (usually 12). The pelvic fins (rays I, 5) usually extend beyond the posterior edge of the pectoral fin, and are inserted very close together. Interpelvic distance is less than half the width of the pelvic fin base.
Analysis of radiographs of 35 specimens from the type locality revealed the following vertebral counts: 35 vertebrae (one speci- men), 36 (17), and 37 Cli):
Coloration of males—The most conspicu- ous feature of nuptial males is the somewhat muted red-orange pigmentation of the lower body. In several male paratopotypes captured on 1 June 1964, this pigment was distributed almost uninterruptedly from just
p> ae.
No. 3 A New Darter 71 TABLE 3 (continued)
4 [5 Pored lateral-line scales > 30 Sl 32 Bs 34 35 36 37 38 39 40 41 42 43 N 7 5 8 2 — 1 109 1 — 1 15 2 2 a 4 3 2 7 5 6 3 2 — al 44
Unpored lateral-line scales
LY 18 19 20 Dall 22 23 24 25 26 Pat | 28 29 30 N 5 19 5 18 19 Lil 3 6 1 5 3 — — 1 109 HES ee 1! 1 4 — — a1 3 4 — 2 —_ 1 15 44
behind the pectoral base to immediately pos- terior to the anal fin origin, and on the lower caudal peduncle in the form of about five indefinite bar-like groupings of orange scales separated by dull olive-green bars. The orange pigmentation on the caudal pe- duncle extended dorsad only to the level of the lateral line. Other males had orange pig- ment before the vent only. Two to four upper body scales in some males also bore orange pigment, but these were scattered and inconspicuous.
In life, and in alcohol, the dorsum is usu- ally uniformly dark brown, broken in most by a predorsal buff-colored nuchal patch of varying width. In some there are about nine very ill-defined darker saddles crossing the dorsal midline and extending laterad on about two scale rows to either side. The intermediate areas between the saddles are brown, similar to the background color, but occasionally are a light brown or buff color. The body at the base of each dorsal fin is buff. In some, the centers of the exposed fields of scales of the dorsum have a slightly darker brown color, giving the impression of vague longitudinal lines extending from the sides of the occiput to the posterior soft dorsal base. The striped pattern extends downward (excluding the lateral line) to the anal base. The stripes are irregularly if at all developed on the lower body, generally being limited to an area on the lateral belly anterior to the anal fin origin and for a short distance on the lower body above the
anal fin. There is no humeral dark blotch. The lateral line is less pigmented along the pored portion than on adjoining areas, and appeared yellowish in life, somewhat as in E. parvipinne Gilbert and Swain. The un- pored lateral-line series appears as an ir- regular light line. Very faint lateral bars (dull olive-green in life) showing some con- nection with the dorsal dark saddles are present in many individuals.
There are three black spots (sometimes connected) in a vertical series at the caudal base. Occasionally the lower and/or median spots are faint or absent. The central spot lies at the termination of the lateral-line series just at or immediately behind the pos- terior edge of the hypural plate. The upper and lower spots lie at the bases of the pos- terior procurrent caudal rays. The caudal base between the spots is usually lighter than on adjoining areas of the peduncle, and in life there was a small spot of red-orange immediately posterior and mesial to the upper and lower basicaudal dark spots.
The genital papilla and anal rugae are im- maculate white. The genital papilla in males takes the form of a short subquadrate flap extending posteriorly to the base of the first anal spine. Occasionally a median short fingerlike projection extends beyond the shorter lateral portions of the papilla.
The lower belly is evenly stippled with micromelanophores. The breast has larger melanophores distributed to the gular region. There is a prepectoral dark blotch.
72 Tulane Studies in Zoology
The head dorsum to the snout is dark brown. The upper snout was buff-colored in life. A dark diffuse line extends from the anterior edge of the orbit below the nostrils to the snout tip, expanding on the anterior third of the upper lip to either side of the buff-colored frenum. The remainder of the upper lip has one or two dark blotches. The posterior maxillary is darkened. The lower lip and lower jaw rami are mottled, and the mandibular symphyseal region usually has a dark blotch. The gular region and branchio- stegal membranes are diffusely stippled. There is a postorbital dark streak. The sub- orbital bar is well-developed, beginning be- hind the lower orbital midpoint and curving downward and slightly forward on the cheek. The iris was golden-orange in life.
The spinous dorsal fin in life was bor- dered by a narrow dusky blue band. Proxi- mal to this was a band of red-orange, about three times as wide as the marginal band anteriorly, tapering to an equal width pos- teriorly. Below this was a slightly wider dusky blue band extending almost to the base of the fin. There was a basal spot of
Vola2
dark red behind each dorsal spine. Nuptial males have melanophores irregularly dis- tributed on the spines.
The soft dorsal fin was dusky blue through- out, always having a basal spot of dark red behind each ray. There was usually some red-orange arranged in one or two indefi- nite narrow bands mesially and submargin- ally. There are three or four dark blotches on the rays.
The anal fin was dusky blue-green on both the spined and soft-rayed portion, with basal red-orange spots on the membranes between the soft rays. Some nuptial males had a median band of orange on the rays. Others had several quadrate dark blotches on yel- lowish rays. The edge of the fin was colorless.
The caudal fin has five to seven irregular dark bars (pigment on rays only). Between the dark bars the rays are yellowish. In a few individuals, the basal portion of the central rays had red-orange pigment extend- ing two-thirds of the distance toward the fin edge. The anterior procurrent caudal rays are embedded in opaque whitish tissue.
TABLE 4.
Distribution of fin-ray counts in Etheostoma ditrema and E. swaini.
Value for
holotype in boldface.
Species Dorsal spines Dorsal soft rays and drainage 8 OS Oeetel eel 2 N 9 10 11 12> snare N ditrema Chattooga Wl by te ala BO) ely i 112 Etowah 1 1 1 1 Choccolocco 6 9 1 16 i 8 “i 16 swaint Alabama ihe Wal ye 44 119, 23 in 1 44 Total dorsal rays 18 19 20 PAA 22, Ze 24 25 N ditrema Chattooga 1 2 48 44 if iLL Etowah if! 1 Choccoloecco 6 3 7 16 swaini Alabama it 9 21 Lal 1 1 44 Anal soft rays Left pectoral rays 6 7 8 N Lal 12 Le 14 N ditrema _ ral Chattooga 40 66 6 2 3 36 29 65 Etowah i 1 1 il Choccoloceco 5 et 16 10 5 155 swaini
Alabama 6 ayil 7 44
A New Darter Ws
TABLE 5. Supratemporal canal and coronal pores in Etheostoma ditrema and E. swaini. Value for holotype in boldface.
Species and Supratemporal canal Coronal pores drainage Complete Interrupted N 1 2 ditrema Chattooga 30 86 116 45 68 latts Etowah 1 1 il 1 Choccolocco 5 ill 16 8 8 16 swaint Alabama 20 24 44 44 44
The pectoral fins are colorless save for a scattering of dusky along the entire length of the rays.
The tissue investing the pelvic spine is only very slightly thickened, and is colorless save for a sprinkling of micromelanophores. The soft-rayed portion had dusky blue-green (darkest between the posterior rays) along the basal two-thirds of the rays and inter- radial membrane. The distal third of the membrane is colorless. The distal portions of the rays have scattered melanophores.
Only two young males are available from the Choccolocco locality. These had sub- marginal and basal red-orange bands in the spinous dorsal fin, but lacked the orange pigment on the venter.
Coloration of females—Females were de- void of erythric pigment on the body. In alcohol the general body coloration is similar to that of males, save they tend to be more mottled, especially on the venter. Chocco- locco females are darker and less mottled, and occasionally the basicaudal dark spots are somewhat ocellate (Fig. 2 and 3).
Only one female from the Chattooga pop- ulation had a submarginal pale orange band in the spinous dorsal, but all adult females from the Choccolocco locality possessed this coloration. Females usually have a dusky
marginal band, which tends to be obsolete anteriorly. There are brownish streaks in the median interradial membranes along the spines. Dusky spots occur basally in the interradial membranes. The spines are vari- ously marked with one or two elongate dusky blotches.
The soft dorsal fin is marked with four or five indefinite bands of brownish pigment, which is distributed on the interradial mem- branes distally and on the rays basally. There is a basal series of interradial dark blotches. The soft dorsal bands are more discrete and narrower in Choccolocco females.
The caudal fin is barred with five to seven irregular rows of dark pigment. The anal fin bears one to three vague dusky brown series of blotches on or adjacent to the rays. The pectoral fin is pigmented as in the male. The pelvic fins are colorless or have scattered melanophores.
The immaculate, slightly crenulate genital papilla of the female projects posteriorly to the base of the first anal spine, and is as long as or slightly longer than broad.
Coloration of juveniles—Juveniles are generally more lightly pigmented than adults. The smallest individuals have moder- ately well-defined dorsal saddles and lateral blotches.
TABLE 6. Squamation of nape in Etheostoma ditrema and E. swaini (see text for explanation of symbols). Value for holotype in boldface.
Species and Degree of nape squamation drainage 0 I I IV V N ditrema Chattooga 24 13 16 8 6 8) 76 Etowah il 1 Choccolocco i — — — 6 9 16 swaini Alabama 25 5 3 fl 10 44
74 Tulane Studies in Zoology
Infraspecific variation—The single speci- ment of E. ditrema from the Etowah drain- age of Georgia is apparently of the same genetic stock as specimens from the type locality in the Chattooga drainage. Members of the Choccolocco population differ mark- edly in several respects: they have the nape more often fully scaled (Table 6); the breast tends to be naked or weakly scaled; the fe- males are darker and less mottled than Chat- tooga females, and more consistently possess an orange submarginal band in the spinous dorsal; the basicaudal dark spots occasionally are ocellate; the second anal spine is stronger. The most striking difference is that the Choccolocco population has a reduced num- ber of dorsal rays. If a separation point in Table 4 is determined as being between 20 and 21 total dorsal rays, the average diver- gence between the Choccolocco population and the Etowah and Chattooga population is about 94 percent. Concurrently, the dor- sal fin bases are more widely separated. These observations suggest that the number of dorsal fin rays has been secondarily re- duced, and that the Choccolocco race is a derivative of a common stock which has been preserved in a more primitive state in the upper Coosa area.
The Choccolocco population likely repre- sents a genetically valid subspecies, but we hesitate to designate it as such in view of the dearth of specimens and lack of knowl- edge of distribution of ditrema throughout the Coosa drainage. There may be a clinal type of variation in probable spring popula- tions of the area surrounding the nearly 60
Vol. 12
airline miles between Lyerly, Georgia and Coldwater, Alabama. In opposition to this view, Mr. Richard D. Caldwell of the Uni- versity of Alabama informs us that E. di- trema was absent from numerous collec- tions made by him in springs of northeastern Alabama.
Relationships—The subgenus Oligoceph- alus retains in part the diversity of composi- tion formerly possessed by the catch-all darter genus Poecilichthys (now a synonym of Etheostoma s.s.). Although evaluation of evolution within Oligocephalus is confused by many secondarily developed characters in the species, it is clear that EF. ditrema is closely allied with the E. asprigene species group. Members of this group are E. as- prigene (Forbes), E. swaini, E. ditrema, and an undescribed species from the Black Warrior-Tombigbee drainage in Alabama. These forms share the following character- istics; nuptial tubercles absent; opercular membranes overlapping or scarcely con- nected; body robust at the level of the spin- ous dorsal origin; supratemporal canal usu- ally or frequently interrupted (much _vari- ation in swatnt and asprigene); lateral line slightly to moderately arched anteriorly; humeral blotch not enlarged, inconspicuous or absent (usually distinct in swatnz); color pattern of red-orange and blue or olive-green on the lower body, red-orange and blue in dorsal and anal fins of males; 35 to 39 vertebrae.
Collette (in press) has found the presence and distribution of breeding tubercles among percids to be of systematic significance. The
TABLE 7.
A comvarison of Etheostoma ditrema and EF. swaini from the Alabama River basin.
Character
Species
ditrema
swaini
Snout shape Spinous dorsal fin n
Greatest known size (s.1.) Horizontal streaks on body Dorsal saddles
Breast
Prepectoral region
Left pectoral rays
Coronal canal
Lateral line contour Pored lateral-line scales Unpored lateral-line scales Seales above lateral line
Decurved, blunt
Spines slender, short; posterior edge gently curved and diagonal to body
42 mm
Absent or indistinct
Absent or indistinct
Usually sealed
Exposed ctenoid scales
Mode at 12
Incomplete, usually 2 pores Moderately arched
19-35
13-30
Mode at 4
Produced, acute
Spines thicker, longer; posterior edge abruptly curved and nearly perpendicular to body
55 mm
Distinct
Distinct
Naked
Naked or with embedded cycloid scales
Mode at 13
Complete, a single pore
Slightly arched
31-43
4-12
Mode at 5
No. 3
asprigene species group forms a_ natural group among atuberculate species of Olzgo- cephalus. Others which appear most closely related are E. exile (Girard), E. grahami, E. lepidum, and E. pottsi (Girard). Etheo- stoma mariae (Fowler) and E. juliae Meek also lack tubercles, but on the basis of mor- phology and pigmentation do not appear as closely related to the asprigene group.
Etheostoma asprigene comprises a com- plex whose most easterly range along the Gulf Coast is in tributaries of the lower Mississippi River in Louisiana and Missis- sippi. Etheostoma swaimi ranges from the Amite River drainage of Louisiana and Mis- sissippi eastward below the fall line to the Apalachicola River drainage of Florida and Georgia (Bailey, Winn, and Smith, 1954).
Etheostoma ditrema appears to be a highly specialized derivative of swaini stock which early surmounted the fall line in the Coosa River system. The nature of the char- acters by which ditrema is distinct from swaini suggests that ditrema has diverged through genetic fixation of developmental traits which in darters are associated with neoteny. Collette (1962) discussed appar- ently neotenic populations of E. (Hololepis) fusiforme (Girard), which are characterized by reduction in adult size, decrease in rela- tive number of pored lateral-line scales, and incomplete development of cephalic canals. All of these characters are found in ditrema as compared with swaini. Collette (1962) found reduction in development of the coro- nal canal in a neotenic population of fzsz- forme, but did not report as great a degree of reduction as that present in ditrema, in which the coronal branches usually do not fuse at all. The assemblage of characters in which E. ditrema seems a paedomorphic species have probably arisen through adapta- tion to the cold spring environment, to which the species presently appears re- stricted.
Other species of Oligocephalus inhabiting the Alabama River system include E. par- vipinne and E. whippli artesiae (Hay), which have the lateral line complete or nearly so, and possess moderately conjoined opercular membranes. Etheostoma parvt- pinne apparently occurs only on the Coastal Plain. Etheostoma whipplii occurs above and below the fall line, but has never been collected with ditrema.
Etheostoma ditrema resembles species of
A New Darter WD
the subgenus Hololepis in the configuration of the lateral line. Two species of Hololepis are reported from the Alabama River sys- tem, including E. fusiforme barratti (Hol- brook) and E. zontferum (Hubbs and Can- non), and a third, E. gracile (Girard), is known from the Tombigbee River system (Collette, 1962). In the Mobile Bay system these occur only on the Coastal Plain. They differ from E. ditrema in possessing nuptial tubercles and in lacking red-orange body pigmentation in breeding males. The lateral line is more highly arched in Hololepis spe- cies. The moderately arched lateral line in E. ditrema seems to be a secondary special- ization, and its similarity to that of Holo- lepis almost certainly represents convergence (probably as does the somewhat arched form of the lateral line in E. exile).
Etheostoma (Psychromaster) trisella Bailey and Richards is known from a unique speci- men collected about midway between two of the known localities of ditrema. Re- peated efforts by several groups to collect further specimens have been futile. Al- though the specimen is distinct in possessing a single weak anal spine, three intense dor- sal saddles, and a complete lateral line, it is possible that the type of ¢rzsella is an aber- rant hybrid between ditrema and another darter. This is rather tenuously suggested by the generally blotched color pattern, the overlapping opercular membranes, and pres- ence of two coronal pores in ¢risella (which the authors mentioned was a probable anom- aly, but which is the usual condition in ditrema ), as well as its apparent absence in the region today. It is understandable that a large-stream form such as E. (No- thonotus) acuticeps Bailey might be collected only rarely, but all habitats (mainly springs and small streams) of the region in which trisella might occur have been surveyed in- tensively.
Habitat and life history—E. ditrema has been collected recently only in or near large springs. We suspect that the “mill- ponds” in which Jordan (1876) found speci- mens were springfed impoundments, as the region of Rome, Georgia has many large springs.
The spring at the type locality boiled from a bed of dolomitic limestone at a rate of about 30 cubic feet per second. The water was cold (16 to 18 C), colorless, and was clear even after heavy rains had roiled neigh-
76 Tulane Studies in Zoology
boring streams. The bottom was composed of a deep bed of soft whitish clay overlaid by detritus and a dense growth of aquatic mosses (Fontinalis filiformis and Fissidens debilis). The greatest depth of water was about two meters. The spring pool was about 15 m in diameter, and was surrounded by brush and open woods. An abrupt break in habitat type occurred with the beginning of moderate flow at the head of the gravelly effluent stream, which was about 2 m wide and choked in place with submerged Spar- ganium americanum.
E. ditrema was the only darter present in the spring pool. It was always associated with dense aquatic vegetation, and individ- uals could occasionally be seen perching at the surface of moss clumps. It was most commonly captured in less than a meter of water, but was also taken as deep as 1.3 m.
Associated fish species in the spring pool at the Chattooga locality included Esox americanus, E. niger, Minytrema melanops, Moxostoma duquesnet, Notropis chrosomus, N. lirus, Semotilus atromaculatus, Ictalurus melas, Lepomis cyanellus, Micropterus s. sal- moides, and Cottus carolinae zopherus. In the effluent stream, the above were taken (except for E. ditrema ), as well as Hypen- telium etowanum, Campostoma anomalum, Notropis c. chrysocephalus, N. xaenocepha- lus, Rhinichthys atratulus, Lepomis m. mega- lotis, Micropterus coosae, Etheostoma (Ulo- centra) coosae, and Percina caprodes car- bonarta.
As Coldwater Spring is the chief water supply for the city of Anniston, Alabama, we were forced to collect in Coldwater Creek just below the spring overflow. The spring flows from a thrust in the Weisner Quartzite formation, and yields 32 million gallons per day. The flow in Coldwater Creek was estimated at 100 cfs. The water was clear, colorless, and cold (18 C). Etheostoma ditrema was the only darter present, and was taken from dense silted patches of Myriophyllum growing in pro- tected pockets along the left stream edge (right edge was polluted from a tributary a short distance below). Several specimens were captured in a muddy ditch near its junction with Coldwater Creek.
Associated species at the Coldwater lo- cality were Lampetra aepyptera, Esox amert- canus, E. niger, Gambusia affinis, Lepomis
Vol. 12
cyanellus, L. macrochirus, and Cottus caro- linae zopherus.
Jordan (1876) took Notropis lirus, Etheostoma stigmaeum, and Percina n. nigro- fasciata with E. ditrema.
Males had assumed nuptial coloration by the end of April. They were still brightly colored in mid-July. It is probable that bright coloration is maintained year-round.
Females were gravid in collections made in April through July, but were largely spent by the latter date. Coldwater females were greatly swollen with eggs on June 1 (Fig.
but did not yield eggs when gently pressed. Ovarian eggs were large and few in number. Chattooga females had eggs of an average diameter of 1 mm on June 1, and 1.2 mm on June 23. One at 40.5 mm s..1. had 25 large ova in the left ovary and 19 in the right. Another at 33.1 mm _ had 23 (left) and 14 (fight). A third vat {3ie/ mm had 23 ripe eggs in the right ovary. The smallest gravid female was 24.4 mm long.
The smallest young available (15.2 mm sl.) was taken at the Chattooga locality on 18 July. Spawning likely occurs throughout the month of June.
The name ditrema refers to the typical possession of two coronal pores.
LITERATURE CITED
BAILEY, R. M., and W. A. GOSLINE. 1955. Variation and systematic significance of vertebral counts in the American fishes of the family Percidae. Misc. Publ. Mus. Zool. Univ. Michigan 93: 1-44.
, and W. J. RICHARDS. 1963. Status of Poecilichthys hopkinsi Fowler and Etheostoma trisella, new spe- cies, percid fishes from Alabama, Geor- gia, and South Carolina. Occ. Pap. Mus. Zool, Univ. Michigan 630: 1-21.
—., H. B. WINN, and Gagc: SMITH. 1954. Fishes from the Escambia River, Alabama and Florida, with eco- logic and taxonomic notes. Proc. Acad. Nat. Sei. Philadelphia 106: 109-164.
COLLETTE, B. B. 1962. The swamp darters of the subgenus Hololepis (Pisces, Perci- dae). Tulane Stud. Zool. 9(4): 115-211.
. In press. The systemat- ic significance of breeding tubercles in fishes of the family Percidae. Proc. U.S. National Mus.
, and R. W. YERGER. 1962. The American percid fishes of the sub- genus Villora. Tulane Stud. Zool. 9(4): 2138-230.
No. 3
DISTLER, D. A., and A. L. METCALF. 1962. Etheostoma pallididorsum, a new percid fish from the Caddo River system of Ar- kansas. Copeia 1962(3): 556-561.
Huss, C. L., and M. D. CANNON. 1935. The darters of the genera Hololepis and Vil- lora. Mise. Publ. Mus. Zool. Univ. Michi- gan 30: 1-93, 3 pl.
a , and K. F. LAGLER. 1958. Fishes of the Great Lakes region. Cran- brook Inst. Sci. Bull. 26: 1-213, 44 pls., 251 figs.
JORDAN, D. S. 1876. A partial synopsis of the fishes of upper Georgia. Ann. Lye.
A New Darter Wil
Nata Hast. Ne. 1 807s.
KUEHNE, R. A., and R. M. BAILEY. 1961. Stream capture and distribution of the pereid fish EH theostoma sagitta, with geo- logic and taxonomic considerations. Co- peta 1961(1): 1-8.
STRAWN, K., and C. Hupps. 1956. Observa- tions on stripping small fishes for experi- mental purposes. Copeia 1956(2): 114- 116.
YERGER, R. W. 1960. Htheostoma okaloosae (Fowler), a percid fish endemic in north- west Florida. Bull. Assoc. Southeastern Biol. 7(2): 41 (abstract).
June 23, 1965
PARASITES FROM LOUISIANA CRAYFISHES FRANKLIN SOGANDARES-BERNAL,
Department of Zoology, Tulane University, New Orleans, Loutsiana
ABSTRACT
Two microsporidians, Thelohania sp. and ? Plistophora sp., and eight trema- todes, Crepidostomum cornutum, Gor- godera amplicava, Microphallus opacus, M. progeneticus, Maritrema obstipum, Macroderoides typicus, Ochetosoma sp., and Paragonimus kellicotti, are report- ed from crayfishes in Louisiana. The presence of the metacercariae of P. kel- licotti is of particular interest since the crayfishes in which this parasite is found are eaten by humans in Louisi- ana.
INTRODUCTION
Nine species of crayfishes have been ex- amined for parasites during studies of para- gonimiasis in Louisiana from 1959-1964.
METHOD OF PROCEDURE
Crayfishes were collected by the most ex- pedient methods and usually transported to my laboratory for examination. The live specimens were usually identified by the late Doctor G. H. Penn, Department of Zoology, Tulane University, or identified with the aid of a key by Penn (1959). The crayfishes were kept in aquaria or finger- bowls until they were decapitated and ex- amined. The muscles and internal organs were separated and carefully teased apart with dissection needles while viewed through a binocular stereoscopic microscope. Most parasites were studied alive under a binoc- ular compound microscope. Specimens not discarded were fixed in Alcohol-Formalin-
* Supported in part by a research grant (AI 038386 TMP) from the National Insti- tutes of Health.
Acetic solution, stained in Van Cleave’s Combination Hematoxylin (Van _ Cleave, 1953), and mounted in Permount (Fisher Sci. Co., N. Y.). The parish of each locality is mentioned the first time the locality is cited in the text.
FINDINGS Protozoa Microsporidia, Nosematidae 1. Thelohania sp. ( Figs. 1-4) Host: Cambarellus shufeldti (Faxon, 1881) Location: Body musculature Localities: Chacahoula (Terrebonne Par. ) and near Covington (St. Tammany Par.), Louisiana
Discussion: Sogandares (1962a) reported this Thelohania sp. from a C. shufeldti col- lected at Chacahoula, Louisiana. Since that time several additional natural infections have been found in the same host species near Covington, Louisiana. Sogandares (1962a) believed his record to be the first for a microsporidian in North American crayfishes. This belief was in error, since Sprague (1950) named in an abstract, The- lohania cambart from Cambarus bartoni from streams along the Georgia-North Caro- lina border. He reported that the sporont (pansporoblast of other authors) of T. cambart gave rise to eight spores which aver- aged 4.6 microns long by 2.2 microns in greatest width, were somewhat oval in shape, being broadly rounded at both extremities, tapered slightly from anterior to posterior, and lacked a persistent sporont membrane.
EDITORIAL COMMITTEE FOR THIS PAPER:
HORTON H. Hosps, JR., Senior Research Scientist, Department of Zoology, U. S. National Museum, Washington, D. C.
HAROLD W. MANTER, Professor of Zoology, University of Nebraska, Lincoln, Ne-
braska
MARY HANSON PRITCHARD, Research Associate, Department of Zoology and Physi- ology, University of Nebraska, Lincoln, Nebraska
80 Tulane Studies in Zoology
The polar filament was reported to be 80- 90 microns long.
Thelohania sp. from Cambarellus shufeldti had pansporoblasts 6-9 microns in diameter, which as a preterminal product contained eight sporoblasts. Each sporoblast formed one spore, resulting in eight spores sur- rounded by the pansporoblast membrane. Live spores measured from 3.0 to 3.5 mi- crons long by 1.2 to 1.6 microns wide. Polar filaments about 15 microns long observed in 3 spores were in all probability only partially extruded.
The Louisiana Thelohania from C. shu- feldti probably represents a different species from T. cambari since the spores differ in size and the pansporoblast membrane of the former is persistent. Thelohania contejeant Henneguy and Thelohan, 1892, the only European species of Thelohania from cray- fishes, has a spore 2 to 3 microns long. Thus, T. sp. from Louisiana has spores which are intermediate in size between more of T. cambart and T. contejeani. The specific identity of the Louisiana Thelohania from C. shufeldti awaits information regarding the filament length and life-history, but low in- cidence of natural infection makes the neces- sary study difficult to complete.
2. ? Plistophora sp. ( Figs. 5-6 )
Host: Cambarellus puer Hobbs, 1945
Location; Body musculature
Locality: Near Covington, Louisiana
Discussion: Sogandares (1962a) reported this form from one C. puer. This species is characterized by 19 to 21 comma-shaped spores, about 6.0 to 9.0 microns long by 4 microns wide, contained in the pansporo- blast membrane. I have not collected this species again.
Platyhelminthes Trematoda, Digenea Allocreadudae 3. Crepidostomum cornutum (Osborn, 1903 ) Stafford, 1904 ( Fig. 7)
Hosts: Cambarellus puer Hobbs, 1945; C. shufeldti (Faxon, 1881); Orconectes lan- cifer (Hagen, 1870); Procambarus clarkii (Girard, 1852); P. blandingi acutus (Gi- rard, 1852); P. penni Hobbs, 1951
Location: Hepatopancreas, heart, pericar-
Figures 1-6. Microsporidians. 1-3. Thelo- hania sp., developing pansporoblasts; 4. same, pansporoblast membrane surround- ing spores; 5A,B,C,D, ?Plistophora sp. variation in shape and size of spores; 6. same, pansporoblast membrane surround- ing spores. [Courtesy Journal of Parasitol- ogy 48(3): 493]
dial membranes and musculature of cephalo- thorax.
Localities: C. puer, C. shufeldti, and O. lancifer from Gibson (Terrebonne Par.) and Maringouin (Iberville Par.); P. clarki from Gibson, Ama, Bonnet Carre Spillway (St. Charles Par.), Sarpy (St. Charles Par.), Amite River on U. S. Hwy. 190 (East Baton Rouge Par.), Maringouin, Bayou close to Rosedale on La. Hwy. 76 (West Baton Rouge Par.), 1.7 mi. N. Junction La. Hwy. 20 on La. Hwy. 309 (Terrebonne Par) eoee blanding: acutus from Amite River on U. S. Hwy. 190; P. penni trom near Pineville (Rapides Par.); all Loiusiana localities.
Discussion: C. cornutum is without doubt one of the most common and widespread trematodes found encysted in Louisiana cray- fishes. Hopkins (1934) reported this spe- cies from crayfishes (listed as Cambarus sp. from Baton Rouge, Amphiuma means Cu- vier, “catfish,” and Ictalurus melas (Rafines- que) (—Ameimrus melas) in Louisiana. Stafford (1931) reported this species from Cambarus spp. in the neighboring state of Mississippi. The crayfishes reported by Hop- kins (1931) and Stafford (1931) cannot be identified because at that time most North American crayfishes were assigned to the genus Cambarus.
Hopkins (1934) and Ameel (1937) both observed that encysted metacercariae of C. cornutum produced eggs. I observed such progenesis frequently in my specimen of C. cornutum trom Louisiana. It is really not known if these eggs are the result of par- thenogenesis or self-matings, or if the re-
No. 3 Crayfish sultant developmental stages are capable of continuing with their normal biological functions of reproduction.
One first intermediate host of C. cornu- tum in Louisiana is a sphaeriid clam of the genus Muasculium. Naturally infected sphaeriids have been collected at Gibson and at a bayou near Rosedale at the junction of La. Hwys. 76 and 413. Cercariae from clams of both localities readily encysted on the sur- face of the heart and hepatopancreas of laboratory reared P. clarkit and C. shufeldtz, lightly encysted matacercariae being found as early as 16 hours postexposure.
Natural definitive hosts of C. cornutum found in this study were Amza calva Linn. and Lepomis macrochirus (Rafinesque). Other hosts in Louisiana have been cited above.
Gorgodertdae 4. Gorgodera amplicava Looss, 1899 ( Figs. 8-10) Hosts: Orconectes palmeri creolanus
(Creaser, 1933), Procambarus clarku (Gi- rard, 1852)
Location: On lower quadrant of stomach wall, usually at level of gastric mill
Localities: O. palmert creolanus from stream drainage into Bayou Sarah, about 1 mile S. Mississippi State Line (West Felici- ana Par.); P. clark from Ama, Bonnet Carre Spillway, Sarpy, Maringouin, Edgard (La- fourche Par.), Buras (Plaquemines Par.), Pierre Pass (Assumption Par.), Venice (Plaquemines Par.), and 1.7 mi. N. Jct. La. Hwy. 20 on La. Hwy. 309.
Discussion: Krull (1935) described the life cycle of this species. The partial life- cycle of G. amplicava has been experiment- ally established in this laboratory in young Rana clamitans Latreille and adult Amphrt- uma means Cuvier. Rana catesbeiana Shaw is one definitive natural host of G. ampli- cava in Louisiana, and has been shown by Penn (1950) to feed on crayfishes. Hyla cimerea (Schneider) and Chaenobryttus gu- losus (Cuv. & Val.) were refractory to in- fection. Judging from the site of encyst- ment, I suspect that crayfishes become in- fected by ingesting the cercariae. Almost all crayfishes collected in Sarpy, an oil field near Norco, Louisiana, were infected with G. amplicava. The species has been previously reported from crayfishes by Krull (1936).
Parasites 81
Microphallidae 5. Microphallus opacus (Ward, 1894) Ward, 1901 ( Figs. 11-13) Host: Cambarellus puer Hobbs, 1945 and Procambarus clarkiit (Girard, 1852) Location: Hepatopancreas
Locality: Bayou close to Rosedale on La. Hwy. 76.
Discussion: M. opacus was the most com- mon metacercaria in P. clarkii at the Rose- dale locality, being found in about 98% of those examined. Ammnicola, probably integra, from the same locality released three differ- ent types of microphallid cercariae, prob- ably corresponding with the 3 microphallid tremadoes encysted in crayfishes from the same bayou.
Encysted specimens of M. opacus were in- jected under the cephalothorax of P. clark and C. per from uninfected localities, but these worms did not produce eggs, even after three weeks, though they did remain alive for this period of time. CF, white mice were fed cysts of M. opacus and gravid specimens were recovered after 24 hours. The reser- voirs for the adults of M. opacus in the Rose- dale locality are unknown, though the species will develop to maturity in a number of vertebrates (Rausch, 1947).
In this laboratory M. opacus would pro- duce eggs in 0.85% NaCl-1:20,000 Strepto- mycin sulfate solution in 12 to 36 hours at 30 C. Metacercariae were artificially ex- cysted by vigorously shaking and incubating the entire infected crayfish hepatopancreas in a pepsin-HCl solution (100 ml. 0.3% HCI and 40 ml. 0.5% pepsin N.F.) at 40 C for 30 minutes, then incubating the washed cysts (0.85% NaCl) in a trypsin solution (0.5% trypsin in 0.85% NaCl, adjusted to pH 7.8 with K2HPO,) held at 40 C for 10-12 min. The excysted metacercariae were then washed in 30 C 0.85% NaCl-1:20,000 Streptomycin sulfate solution and later in- cubated in the same but clean solution. Thousands of clean excysted metacercariae could be obtained by following the above method.
Rausch (1947) observed that when meta- cercariae of M. opacus were left in crayfish hepatopancreas extract overnight at room temperatures they excysted, found partners and began to mate. Ward (1900) also ob- served worms from natural infections 1
82 Tulane Studies in Zoology Vol. 12
0.5
WRIELIL REY,
7 PER x
KTP RS LH ¥ Sx > FERS
PSR
Figures 7-20. Digenetic Trematodes. 7. Crepidostomum cornutum, excysted metacercaria; 8. Gorgodera amplicava, excysted metacercaria; 9. same, adult from experimental infec- tion of Amphiuma; 10. same, eggs; 11. Microphallus opacus; excysted metacercaria; 12. same, adult from experimental infection of CF, mouse; 13. same, dorsal view of termi- nal genitalia; 14. Microphallus progeneticus, adult from Cambarellus puer; 15. same, ter- minal genitalia; 16. same, egg containing miracidium; 17. Maritrema obstipwm, excysted metacercaria; 18. same, terminal genitalia; 19. Macroderoides typicus, excysted meta- cercaria; 20. Paragonimus kellicotti, excysted metacercaria. The projected scales have their values indicated in millimeters. All figures accompanied by a projected scale were drawn with the aid of a Leitz camera lucida for inclined microscopes. Those figures lack- ing a scale are sketches.
No. 3 Crayfish copula. In several experiments in this labo- ratory, encysted metacercaries from post- pepsin-HCl treatment were individually iso- lated and incubated in trypsin-saline solu- tion. The resulting excysted worms, which had not been able to mate with a partner, were individually isolated in 4 x 40 mm tubes containing NaCl-Streptomycin solution and kept at room temperature. Approxi- mately 11% of the single worms treated as indicated above produced eggs of unascer- tained viability. By following almost the same procedure in another experiment, 50 pairs of excysted M. opacus metacercariae were placed in identical tubes (2 worms per tube) and solutions. Eighty-four percent of these worms produced eggs, the viability of which was not determined. Further experi- mentation on this aspect has not been con- tinued since a severe drought in 1963 deci- mated the snail and crayfish populations. At present it is not known if mating is always necessary for the production of viable eggs, nor is it known if temperature or possible increase in titer of materials released by the mated pairs was responsible for egg produc- tion. Ching (1963a), for example, has in- dicated that increased (30 to 40 C) temper- ature stimulated egg production in Leven- sentella charadriformis Young, 1949. In an- other experiment (Ching, 1964b), she did not observe egg production of another micro- phallid, Maritrema laricola Ching, 1963, when held at 30 to 40 C. The viability of the eggs of the former species was not tested. Experiments of this type are neces- sary tO answer Certain questions of interest to trematode specialists. For example: Are eggs from isolated worms a result of par- thenogenesis or self-fertilization? Are the developmental stages of eggs produced by “self-matings” viable throughout their life- cycles? If self-matings are possible, what is the statistical significance of such self- matings on the species population structure?
6. Microphallus progeneticus Sogandares, 1962 ( Figs. 14-16)
Host: Cambarellus puer Hobbs, 1945, Procambarus clarku (Girard, 1852)
Location: Cephalothoracic cavity
Locality: Gibson, Maringouin, Bayou close to Rosedale on La. Hwy. 76, Louisiana.
Discussion: This species, first found by Dr. Joseph Fitzpatrick, then a graduate stu-
Parasites 83
dent and assistant in my laboratory, was described by Sogandares (1962b). It is unique in lacking a complete pharynx and may be gravid when unencysted and wander- ing over the organs of the cephalothorax of the affected hosts. Eggs im wtero contain actively moving miracidia.
Live specimens of Microphallus progene- ticus were intubated per ora into several CF, laboratory mice, but none were recoy- ered upon necropsy after 24 hours. The worms presumably were passed or digested by the host mice. M. progeneticus, except for the lack of a pharynx, is close to M. opacus, and may represent a sibling species of the latter. However, M. opacus is encysted and M. progeneticus is free in the crayfish hosts. Even if M. opacus could excyst in a crayfish host under certain conditions, which seems unlikely, excysted specimens experi- mentally introduced into the hemocoels of crayfishes failed to mature in three weeks, (see under M. opacus), though maturation took place in CF, laboratory mice and 7m vitro, It seems unlikely that gene flow be- tween the two forms could occur even if both were ingested by a single vertebrate host.
7. Maritrema obstipum (Van Cleave and Mueller, 1932) Mueller, 1934
(Figs. 17-18)
Host: Cambarellus shufeldti (Faxon, 1881) and Procambarus clarku (Girard, 1852)
Location: Central shaft of gill filaments and hepatopancreas
Locality: Bayou close to Rosedale on La. Hwy. 76, Louisiana
Discussion: This species was first observed by me in the gill filaments of its hosts. Later, great numbers were easily recovered from the hepatopancreas of affected hosts with the excystment procedure described under Microphallus opacus. Etges (1953) studied the life-history of Maritrema ob- stipum and found it encysted in the isopod Asellus communis. His identification of Maritrema obstipum seems doubtful at pres- ent, and completion of the life-history of the forms from crayfishes may elucidate the identity of his species. The first intermedi- ate host reported by Etges (1953) was Am- nicola pilsbryt. One of the three microphal- lid cercariae from Ammnzicola, reported under
84 Tulane Studies in Zoology
Microphallus opacus, is probably the larva of this species. Stafford (1931) reported a Maritrema sp. from Cambarus in Mississippi.
Plagiorchitdae 8. Macroderotides typicus (Winfield, 1929 ) Van Cleave and Mueller, 1932 (Figil9 )
Hosts: Procambarus blandingi acutus (Gi- rard, 1852) P. clark (Girard, 1952), and Orconectes lancifer (Hagen, 1870)
Location: Cephalothoracic and antennal musculature
Localties: P. blandingi acutus and P. clarku from Edgard, P. clarku from Bayou near junction of La. Hwys. 413 and 76 (West Baton Rouge Par.), and O. lancifer from Gibson, Louisiana.
Discussion: Macroderoides typicus also utilizes tadpoles as second intermediate hosts (McMullen, 1935). The cercaria emerges from Helisoma trivolvis lentum in Louisi- ana. Adults of M. typicus have been found in Amia calva Linn. from Louisiana. Ex- posure of various species of sunfishes to cysts of M. typicus produced negative results.
9. Ochetosoma sp. Host: P. clarkui (Girard, 1852) Location: Abdominal musculature
Locality: Bayou close to Rosedale on La. Hwy. 76, Louisiana
Discussion: Adult hosts of Ochetosoma in Louisiana are usually snakes of the genera Natrix and Agkistrodon. Certain species of Louisiana Ochetosoma are known to utilize physid snails and tadpoles as intermediate hosts (Byrd, 1935). Physids, tadpoles, and watersnakes were present in the locality in which the crayfishes were found infected with Ochetosoma. Penn (1950) has indi- cated that certain watersnakes feed heavily on crayfishes. Ninety-seven of 100 cray- fishes from the locality were found infected with Ochetosoma.
Troglotrematidae 10. Paragonimus kellicotti Ward, 1908 ( Fig. 20) Hosts: Procambarus blandingi acutus (Gi- rard, 1852) and P. clarki (Girard, 1852)
Location: Heart and surrounding mem- branes
Voleil2
Locality: Amite River on U. S. Hwy. 190
Discussion: My colleague, Dr. E. A. Malek, and I first collected this species in crayfishes. Experimental infections have been established in his and my laboratories, and a separate paper describing our results is in preparation.
SUMMARY
Parasites found in Louisiana crayfishes during this study are listed in Table 1. All localities visited for collection of crayfishes are indicated in Figure 21. Localities from which infected crayfishes were taken are in- dicated, under the specific parasite being considered, in the text. Where possible, local, experimental, and natural intermediate and definitive hosts of parasites discussed are cited in the text.
The parasites found inhabiting crayfishes in Louisiana are represented by two micro- sporidians of the Nosematidae, and 8 dige-
Se |
Map showing collecting locali-
Figure 21. ties in Louisiana. Areas visited are indi- cated by dark circles.
netic trematodes by one species of Allo- creadiidae, one species of Gorgoderidae, three species of Microphallidae, two species of Plagiorchiidae, and one species of Tro- glotrematidae.
The presence of Paragonimus kellicotti, the North American mammalian lung fluke, is of particular interest since the specific hosts in which this parasite was found are utilized as food by humans in Louisiana.
Host-PARASITE INDEX
Cambarellus puer Crepidostomum cornutum Microphallus opacus Microphallus progeneticus ?Plistophora sp.
Cambarellus shufeldti Crepidostamum cornutum Maritrema obstipum Thelohania sp.
Orconectes clypeatus (Hay, 1899) Negative
Orconectes lancifer Crepidostomum cornutum Macroderoides typicus
Orconectes palmeri creolanus Gorgodera ampuicava
Procambarus clarkii Crepidostomum cornutum Gorgodera amplicava Macroderoides typicus Maritrema_ obstipum Microphallus opacus Microphallus progeneticus Ochetosoma sp. Paragonimus kellicotti
Procambarus blandingi acutus Crepidostomum cornutum Macroderoides typicus Paragonimus kellicotti
Procambarus penni Crepidostomum cornutum
Procambarus vioscai (Penn, 1946) Negative
4
LITERATURE CITED
AMEEL, DONALD J. 1937. The life history of Crepidostomum cornutum (Osborn). J. Parasitol. 23: 218-220.
Byrp, ELON E. 1935. Life history studies of Reniferinae (Trematoda, Digenea) para- sitic in Reptilia of the New Orleans area. Trans. Am. Microscop. Soc. 54: 196-225.
CHING, HILDA LEI 1963a. The life cycle and bionomics of Levenseniella charadrifor- mis Young, 1949 (Trematoda: Microphal- lidae). Canad. J. Zool. 41: 889-899.
1963b. The description and life cycle of Maritrema laricola sp. n. (Trematoda: Microphallidae) Canad. J. Zool. 41: 881-888.
ETGES, FRANK J. 1953. Studies on the life histories of Maritrema obstipum (Van Cleave and Mueller, 1932) and Leven- seniella amnicolae n. sp. (Trematoda:
Crayfish Parasites 85
Microphallidae). 662.
HopPkKINS, SEWELL HEPBURN 1934. The pap- illose Allocreadiidae. JIl. Biol. Monogr. 18: 45-124.
KRULL, WENDELL H. 1935. Studies on the life history of a frog bladder fluke, Gor- godera amplicava Looss, 1899. Pap. Mich. Acad. Arts & Letters 20:697-710.
ae . 1936. Additional second intermediate hosts for Gorgodera ampli- cava Looss, 1899. Proc. Helm. Soc. Wash.
3 OSs
McMULLEN, DONALD B. 1935. The life his- tory and classification of two allocrea- diid like plagiorchids from fish, Macro- deroides typicus (Winfield) and Allo- glossidium corti (Lamont). J. Parasitol. 21: 369-380.
PENN, GEORGE HENRY 1950. Utilization of crawfishes by cold-blooded vertebrates in the Eastern United States. Am. Midl. Nat. 44: 643-658.
J. Parasitol. 39: 643-
summary of their distribution within the state (Decapoda: Astacidae). Tulane Stud. Zool. 7: 3-20.
RAUSCH, ROBERT 1947. Some observations on the host relationships of Microphallus opacus (Ward, 1894). Trans. Am. Micro- scop. Soc. 66: 59-63.
SOGANDARES-BERNAL, FRANKLIN 1962a. Pre- sumable microsporidiosis in the dwarf crayfishes Cambarellus puer Hobbs and C. shufeldti (Faxon) in Louisiana. J. Parasitol. 48: 4938. ee ee ees 1962b. Microphallus pro- geneticus, a new apharyngeate progenet- ic trematode (Microphallidae) from the dwarf crayfish, Cambarellus puer, in Louisiana. Tulane Stud. Zool. 9: 319-322.
SPRAGUE, VICTOR 1950. Thelohania cambari n. sp., a microsporidian parasite of North American crayfish. J. Parasitol. 36 (Sec Ai AG:
STAFFORD, E. W. 1931. Platyhelmia insects and crustacea. J. Parasitol. 18:1381.
VAN CLEAVE, HARLEY J. 1953. Acanthoce- phala of North American Mammals. /Il. Biol. Monogr. 23: 1-179.
WarbD, HENRY B. 1900. Notes on the para- sites of the lake fish III. On the struc- ture of the copulatory organs in Micro- phallus nov. gen. Trans. Am. Microscop. Soc. 22: 175-187, 5 figs.
June 23, 1965
A NEW SUBSPECIES OF THE CRAWFISH ORCONECTES LEPTOGONOPODUS FROM THE OUACHITA RIVER DRAINAGE IN ARKANSAS
J. F, PITZPATRICK,. JR:,
Department of Biology, University of Virginia, Charlottesville?
ABSTRACT
A new subspecies of the crawfish Orconectes leptogonopodus Hobbs, O. l. acares, is described from the Ouachita River drainage in Arkansas. The new race is distinguished from the typical subspecies by shorter terminal elements of the first pleopod, a shorter pleopod, and other minor differences. Orconec- tes leptogonopodus leptogonopodus is recorded from Oklahoma.
An excellent series of Orconectes lepto- gonopodus Hobbs (1948) was found among Tulane University lots of Ozark-Ouachita crawfishes sent to me for identification by Dr. George H. Penn shortly before his death. About the same time Dr. Horton H. Hobbs, Jr., of the United States National Museum sent an “interesting” series of the species collected by Dr. A. P. Blair from the Caddo River drainage. Examination of this large series revealed that Ouachita River popula- tions of O. leptogonopodus are morphologic- ally distinct from the topotypic population of O. leptogonopodus and from other popula- tions located in tributaries of the Red River. Accordingly, the Ouachita populations are recognized as subspecifically different from the Red River populations of O. leptogo- nopodus and a new subspecies is described.
In addition to the persons mentioned above, the writer is indebted to Dr. Alfred E. Smalley of Tulane University who has
1 Present Address: Department of Zoolo- gy, Mississippi State University, State Col- lege, Mississippi.
permitted the selection of type material to be distributed as noted below.
The name of this new subspecies is taken from the Greek, acares, short; it is so named because a prominent characteristic is the short, in comparison with /. leptogonopodus, terminal elements of the first pleopod.
ORCONECTES LEPTOGONOPODUS ACARES, subsp. nov. Synonymy. Orconectes leptogonopodus Williams, 1954 (in partim).
Diagnosis; Pigmented; eyes normal. Ros- trum with marginal tubercles or spines, median carina present, margins subparallel or slightly converging cephalad, not thick- ened; length of areola 29.1 to 33.7 (mean 31.8) per cent of total length of carapace, 5.5 to 7.0 times longer than broad, three to five punctations in narrowest part. Post- orbital ridges strong, terminating cephalad in strong, divergent, corneous spines or tu- bercles; sides of carapace lacking lateral spines. First pleopod of first form male reaching caudal margin of coxopodite of first pereiopod with abdomen flexed; cen- tral projection with strong cephalic shoulder near base; central projection straight, longer than mesial process [ratio of central pro- jection length to mesial process length 1.25 to 1.54 (mean 1.34)}, slender, with tip curving caudodistally; mesial process straight, setiform, slender, delicate; tips of first pleo- pod divergent (Figs. A, E). Annulus ven-
EDITORIAL COMMITTEE FOR THIS PAPER:
HorTON H. Hoss, JR., Senior Scientist, Department of Zoology, United States Na- tional Museum, Washington, D. C.
ALFRED E. SMALLEY, Assistant Professor of Zoology, Tulane University, New Or-
leans, Louisiana
AUSTIN B. WILLIAMS, Professor of Zoology, University of North Carolina Institute for Fisheries Research, Morehead City, North Carolina
87
88 Tulane Studies in Zoology Volew2
Figures A-J. Orconectes leptogonopodus acares.
Legend. A. Mesial view of first pleopod of holotype; B. Mesial view of first pleopod of morphotype; C. Dorsal view of carapace of holotype; D. Lateral view of first pleopod of morphotype; E. Lateral view of first pleopod of holotype; F. Annulus ventralis of allo- type; G. Right chela of holotype, upper view; H. Epistoma of holotype; I. Antennal scale of holotype; J. Basipodite and ischiopodite of third pereiopod showing hook. (Me- sial process of holotype slightly warped in preservation; in life, it is less divergent and is straight.)
No. 3
tralis immovable, subrhomboid in outline, with prominent tongue-like caudal projec- tion, deep transverse trough in anterior half; sinus originating in trough, winding sinu- ously either sinistrally or dextrally, disappear- ing in caudal margin (Fig. F).
Holotypic male, Form I; Body subcylin- drical, slightly depressed. Abdomen nar- rower than cephalothorax (8.5, 8.7 mm in widest parts, respectively). Width of cara- pace greater than depth in region of caudo- dorsal margin of cervical groove (8.7, 6.9 mm ).
Areola moderately broad (6.8 times longer than wide) with two or three punctations across narrowest part. Cephalic section of carapace about 1.9 times as long as areola. Length of areola 34.3 per cent of entire length of carapace. Dorsal features of cara- pace illustrated in Figure C.
Rostrum with slightly converging margins; margins not distinctly thickened, but ter- minating cephalically in strong spines; upper surface deeply concave, bearing setiferous punctations, and with a moderately devel- oped median carina. Acumen short, broad; extending to distal end of peduncle of anten- nule; tip not upturned. Subrostral ridges evident in dorsal aspect for a short distance at bases.
Postorbital ridges strong, grooved dorso- laterally, projecting cephalad in strong di- vergent spines. Suborbital angle acute. Branchiostegal spines acute. Carapace with a weakly developed tubercle on each lateral surface at level of branchiocervical groove. Entire carapace studded with setiferous punctations except extreme cephalolateral ventral portions which bear setiferous granu- lations.
Abdomen shorter than carapace (17.2, 17.8 mm). Cephalic section of telson with two spines in each caudolateral corner.
Epistome (Fig. H) subcircular in outline with cephalomedian tubercle.
Antennules of usual form with prominent spine on ventral surface of basal segment. Antennae broken, but appear to have ex- tended to posterior region of abdomen. An- tennal scale (Fig. 1) about 2.2 times longer than broad, mesial margin of lamellar por- tion evenly rounded, widest distal to mid- length.
Chela (Fig. G) depressed, palm inflated; all surfaces bearing setiferous punctations. Tubercle present on lower surface of palm
New Crawfish 89
at base of dactyl. Inner margin of palm with two irregular rows of tubercles, lower row of seven and upper row of six. Fingers with slight gap at base. Upper surface of immovable finger with broad, rounded, sub- median, longitudinal ridge flanked by seti- ferous punctations; another ridge along proximal three-fourths of finger immedi- ately mesial to aforementioned ridge. Outer margin of immovable finger with well- defined keel extending proximally two- thirds length of palm; opposable margin of finger with row of two small, one large, and three small tubercles (proximal to distal ) etxending along basal two-thirds and crowd- ed minute denticles along distal one-third; submedian longitudinal ridge on lower sur- face of finger. Dactyl similar to immovable finger above and below; mesial margin with double row of tubercles along proximal one- third, lower row of three but upper row with only one well-defined tubercle; oppos- able margin with five small tubercles along basal two-thirds and crowded minute denti- cles in distal one-third.
Carpus of cheliped longer than broad and with broad shallow longitudinal furrow above; setiferous punctations over entire sur- face and few small tubercles on upper sur- face mesial to furrow; mesial surface with prominent tubercle on upper proximal one- third, strong acute spine on lower middle one-third, and tubercle on upper mesiodistal margin: lower submedian distal margin and lower laterodistal margin each with strong spine. Upper and lower surfaces of merus with scattered setiferous punctations; lateral surfaces generally smooth; three spines in line on upper distal surface; lower mesial surface with row of nine tubercles increas- ing in size distally, terminating in strong acute distal spine; single acute distal spine on lower laterodistal margin and row of one spine and nine tubercles proximal to distal spine. Lower surface of ischiopodite with small rounded tubercle. Hooks on ischiopo- dites of third pereiopods only (Fig. J); hooks simple.
First pleopod extending cephalad to caudal margin of coxa of first pereiopod with ab- domen flexed. Tip terminating in two dis- tinct parts, both slender and setiform; rami separated for considerable distance from tips and moderately divergent (Figs. A, E). Cen- tral projection corneous, straight, but with tip curved caudodistally. Mesial process not
90 Tulane Studies in Zoology
extending so far distad as central projection, non-corneous, and quite delicate. (Delicate nature of mesial process results in preserva- tion artifacts; so noted in figure of holo- type.) Pleopods symmetrical (sensu Hobbs, 1962).
Morphotypic male, Form Il: Differs from holotype in following respects: lateral tuber- cles of cephalothorax lacking. Carpus of cheliped with upper mesiodistal spine. Palm less inflated and proportionately smaller than holotype. Hooks on ischipodites of third pereiopods much reduced. Both elements of pleopod (Figs. B, D) non-corneous, blunter and in close apposition along basal three- fourths.
Allotypic female: Differs from holotype in following respects: palm proportionately smaller and less inflated than holotype. First pleopod biramous and weakly developed.
Annulus ventralis immovable, subrhom- boid in outline with prominent tongue-like projection of caudal margin, fused ceph- alically with sternum but with two promi- nent lateral tubercles raised (ventrally) in cephalic half. Deep transverse trough in cephalic half, with aforementioned tubercles overhanging cephalolateral portions. Sinus originating in trough, curving gently caudo- sinistrally, then caudally following sinuous path to caudal margin of annulus (Fig. F).
Type locality: Stream tributary to Ouach- ita River, 6 mi. northwest of Mt. Ida, Mont- gomery County, Arkansas.
Disposition of the types: The holotypic male, Form I; the allotypic female; and the morphotypic male, Form HI, are in the col- lections of the United States National Mu- seum (mos. 115517, 115518, and 115519, respectively ). Paratypes are deposited in the
Vol. 12
U. S. National Museum (nos. 114821 and 114822), the Museum of Comparative Zo- ology, Harvard University (no. 12637), Tu- lane University (parts of Lots 2500, 2956, 3081, 3082, 3083, 3150, 3346, 3364, 3443, 3444, 3450, and 3451), and in personal col- lections of the author. The paratypic series is a total of 218 specimens representing both forms of the male, females, and juveniles of both sexes. The specimens at MCZ and in collections of the author are among speci- mens designated topoparatypes.
Range: This subspecies is confined to tributaries of the Ouachita River and has been collected from the following counties in Arkansas: Garland, Hot Springs, Mont- gomery, Perry, Pike, Polk, and Saline.
Variations: There are relatively few vari- ations in the specimens examined. In some there are less pronounced cephalomedian projections of the epistome, and in a few specimens the projection is lacking. In some specimens the terminal elements of the pleo- pod are longer than usual, resulting in a greater central projection: mesial process ratio. Lateral tubercles of the carapace are lacking in many specimens.
Relationships: Orconectes leptogonopodus acares has its closest affinities with O. /. leptogonopodus Hobbs. Although there are no evidences of intergrade populations among the specimens examined, Jones Creek and Caddo River specimens show definite tendencies toward typical leptogonopodus morphology, and specimens of O. leptogo- nopodus leptogonopodus from McCurtain County, Oklahoma, show definite tendencies toward morphological features of O. lepto- gonopodus acares. O. |. leptogonopodus appears to be restricted to tributaries of the
TABLE I. Measurements of type specimens of Orconectes leptogonopodus acares. (All measurements in mm)
Holotype
Carapace— height 6.9 width 8.7 length 17.8 Areola— length 6.1 width 0.9 Rostrum— length 4.9 width 2.8
Chela— length of inner margin of palm 5.0 width of palm 6.5
length of outer margin of palm 14.1 length of dactyl 8.5
Allotype Morphotype 10.4 1.5 8.7 8.7 25.3 18.0 8.6 5.9 Wee ileal 5.9 5.0 3.4 3.0 7.0 4.8 8.5 6.3 19.1 12°59 10.7 Coll
No. 3
Red River in Arkansas and eastern Okla- homa, while O. /. acares, is confined to tributaries of the Ouachita River, from the Caddo River upstream. O. /. acares may be distingiushed from O. |. leptogonopodus by a shorter pleopod, a shorter central pro- jection, and a smaller central projection: mesial process ratio (mean value for acares: 1.34; for /eptogonopodus: 1.43). In O. /. acares there is a greater tendency toward development of a cephalomedian projection of the epistome, and there are slight differences between the two subspecies in outline of the cephalic margin of the annuli ventrales.
Remarks: Orconectes leptogonopodus has never been reported from outside the state
of Arkansas, but two collections in the USNM are from Oklahoma: (1) 8 Oct.
New Crawfish 91
1955, McCurtain Co. (?), Eagle Creek, trib. to Mountain Fork Riv., nw of Smithville, coll. A. P. Blair (2?) (Hobbs Collections ) ; and (2) 28 Nov. 1963, McCurtain Co., Broken Bow, 6 NNE, coll. A. P. Blair, and both of these contained specimens which I identified as O. 1. leptogonopodus.
LITERATURE CITED
Hopss, H. H. Jr., 1948. Two new crayfishes of the genus Orconectes from Arkansas with a key to the species of the Hylas Group. Amer. Midl. Nat. 39: 189-150.
Pameedt s «B _., 1962. Notes on the af- finities of the members of the Blandingii Section of the crayfish genus Procam- barus. Tulane Stud. Zool. 9: 273-298.
WiuurAMs, A. B. 1954. Speciation and dis- tribution of the crayfishes of the Ozark Plateaus and Ouachit: Provinces. Univ. Kansas Sci. Bull. 36: 808-918.
June 23, 1965
‘s as (ie A
+ ; - ’ ae ao oh i siG at wrth 185 oe; ‘ »f nr | : a 7 n TE A. 4 ‘ i \ , ' — S be = \ ‘ oe t ” | a 7
Volume 12, Number 4
TULANE STUDIES IN ZOOLOGY
October 11, 1965
ECOLOGICAL DISTRIBUTION AND ACTIVITY PERIODS OF BATS OF THE MOGOLLON MOUNTAINS AREA OF NEW MEXICO AND ADJACENT ARIZONA
CLYDE JONES Department of Biology, Tulane University New Orleans, Loutstana
ABSTRACT
Data concerning ecology and distri- bution are presented and summarized for 19 species of bats from southwest- ern New Mexico and adjacent south- eastern Arizona. Time of capture and air temperature at time of capture are given for all species. Environmental factors that may influence activity and distribution of bats are discussed.
INTRODUCTION
Few observations have previously been published on bats in New Mexico, and in- formation on general ecology has often been incidental to distributional or taxonomic studies. Bailey (1931), while presenting geographic ranges of bats known from New Mexico, made some mention of ecology and natural history. More recently, limited eco- logical information has been contributed by Mumford (1957, 1964), Commissaris (1959), Findley (1960), Constantine (196la, b), Harris (1963), and others. Sheppard (1962) assembled natural history and ecological data for the species of bats occurring in Bernalillo Co., New Mexico.
The purpose of this report is to furnish information concerning distribution and gen- eral ecology and to discuss briefly the factors that may influence activity and distribution of bats of the Mogollon Mountains area of southwestern New Mexico and adjacent southeastern Arizona.
DESCRIPTION OF THE AREA
Fenneman (1931) included the northern part of the study area (north of 33° N lat) in the Datil section of the Colorado Plateau physiographic province and the southern part (south of 33° N lat) in the Mexican Highland division of the Basin and Range province. The study area is composed of a portion of the Mogollon Rim and several semi-isolated and isolated smaller mountain ranges bordered on the north by the closed basin of the San Augustin Plains and on the east and south by the Rio Grande and Gila River drainages (Fig. 1). From the lowest elevation of 3,800 ft on the Gila River at the Arizona-New Mexico border the altitude rises to 10,788 ft in elevation at the highest point, Mogollon Peak. Precipitation in the area is variable, ranging from about 10 to 16 inches annually (little or no weather data are available from montane areas), with the heaviest rainfall occurring in July and Au- gust (Hardy, 1941).
The Mogollon Mountains area has biotic communities characteristic of the southern Rocky Mountains (Lowe, 1964). For the purposes of this study, three biotic com- munities are recognized.
Xeric-shrub grassland —Present and wide- spread below 6,000 ft except for restricted stands of evergreen and deciduous vegeta- tion on north-facing slopes and canyon
EDITORIAL COMMITTEE FOR THIS PAPER:
ANDREW A. ARATA, Associate Professor of Zoology, Tulane University, New Orleans,
Louisiana
Dr. MARTIN EISENTRAUT, Museum Alexander Koenig, Bonn, West Germany
PHitip H. KRUTZSCH, Professor and Head of Anatomy, College of Medicine, Uni-
versity of Arizona, Tucson, Arizona
94 Tulane Studies in Zoology
floors. Conspicuous species of plants found in the xeric-shrub grassland are Muhlen- bergia wrightu, Bouteloua gracilis, Atriplex canescens, Chrysothamnus spp., Larrea tri- dentata, Prosopis juliflora, and P. pubescens with Populus spp., Tamarix gallica, and Ele- agnus angustifolia commonly riparian.
Evergreen-deciduous woodland.—Present throughout the study area from below 5,000 ft on north- facing slopes to above 7,000 ft on ridges and south-facing slopes. Some plants that make up the evergreen-deciduous woodland are Juniperus monosperma, J. sco- pulorum, J. deppeana, Pinus edulis, Quercus grisea, O. gambeli, and Cercocarpus brevi- florus.
Evergreen forest—Widespread above 7,000 ft, present in restricted stands at lower elevations and in heads of cool, mesic can- yons. Some common species of plants of the evergreen forest are Pinus ponderosa, P. flexilis, P. edulis, Picea engelmannit, P.
APACHE CO.
Volz
pungens, Abies concolor, A. lastocarpa, A. lastocarpa var. arizonica, Pseudotsuga men- stesit, Quercus gambeliu, and Populus tremu- loides with Salix spp., Alnus tenutfolia, and Acer spp. often riparian.
METHODS AND MATERIALS
Bats were, for the most part, captured in mist nets stretched across water tanks, over ponds and streams, or over entrances to mines and caves. Nets were maintained ordinarily for 5 to 6 hrs per night. Attempts were often made to maintain nets all night, however, nets frequently were left standing unattended all night and were checked dur- ing the early nots hours. In addition to those netted, a few bats were shot. Most data presented, hee were gathered in 1960, but limited field studies were conducted from 1958 through 1963.
Whenver possible, time of capture, air temperature at the time of capture, and sex
CATRON
co.
Figure 1. Map of the study area showing biotic communities and collecting stations. Ev- ergreen forest is represented by lined areas, evergreen-deciduous woodland is represented by white areas, and xeric-shrub grassland is represented by stippled areas. The distribu- tion of collecting stations is a reflection of the presence of permanent water over which to sample bats.
No. 4
of each individual were recorded upon col- lection of the bat. Data on time of capture and air temperature at the time of capture were analyzed and compared by means of standard _ statistical methods; arithmetic mean, standard deviation, and standard error of the mean were computed. Because there were no significant differences between the two sexes in time of capture or air tem- perature at time of capture, data for males and females were combined. Weather con- ditions were noted in an attempt to deter- mine the role of such factors as wind, rain, and moonlight in relation to activity of the animals studied.
In all, 1595 specimens were obtained from the study and were preserved in the Museum of Southwestern Biology at the University
Bat Ecology 95
of New Mexico either as standard museum study skins and skulls with carcasses pre- served in fluid or were preserved entire in fluid. RESULTS
The Chiropteran fauna of each of the biotic communities is summarized in Table 1. On the basis of the data presented herein, 13 species of bats are considered to be high- land forms (greatest percentage of individ- uals collected were from localities in ever- green forest generally above 7,000 ft in elevation), and six species are regarded as lowland forms (greatest percentage of in- dividuals collected were taken at localities in xeric-shrub grassland and evergreen- deciduous woodland mostly below 7,000 ft in elevation). Myotis occultus is equally
TABLE 1.
Percentage of each species and percentage of all bats collected in each biotic community, as well as bats collected per station (number of bats collected in a community divided by the number of collecting stations in that community) in each biotic community.
Percent of total number taken in xeric-shrub grassland
Total number taken
Myotis californicus 22, Myotis evotis 61 Myotis keenii 42 Myotis oceultus 66 45.5 Myotis subulatus 35 13.5 Myotis thysanodes 84 Myotis velifer 3 33.4 Myotis volans 226 Myotis ywmanensis 137 89.6 Lasionycteris noctivagans 105 Pipistrellus hesperus 43 58.1 Eptesicus fuscus Pat | 1.5 Lasiurus borealis 4 Lasiurus cinereus 191 252, Plecotus phyllotis oH Plecotus townsendii 39 8.0 Euderma maculatum 7 Antrozous pallidus 95 45.2 Tadarida brasiliensis 126 32.8 Tadarida molossa 1 Total 1595 Mays
oO ne = fo) ie) we = S ene S zg 3 : Pe e See F SE ue ae he 28 88 82 & =o ns nw No nN a Sy SS 8 a a) as atl o o 2 Ou Sa Qe a, 2,2 2,0 aay SS Pai oe ics ot oes of oR oF 2 § 2 § $8 gs 89 BE 32 25 985 #22 28 uf a] ~ ov as cf 82 85 4&8 35.0 65.0 el .68 100.0 3.05 14.3 85.7 66 1.86 54.5 2.0 1.80 20.5 65.0 5333 .88 1-26 At 95.3 44 4.31 66.6 .06 Ape 2.6 97.4 .66 11.00 5.2 baz 3.46 $33 5 25.8 74.2 3.00 4.10 39.5 2.4 1.66 1.42 .05 9.0 89.5 .26 Patty 12.40 100.0 44 41.3 56.5 26 Satu 5.86 9.7 90.3 .30 1.47 18.4 73.6 .20 hat 1.47 100.0 .36 37.4 17.4 2.86 4.00 .84 54.4 1278 Zale 75D 84 100.0 05 19.9 66.4 13.80 33.50 50.30
96
distributed in the xeric-shrub grassland and in evergreen forest, whereas Myotzs evotis is restricted to the evergreen-forest community. Myotis velifer, Lasiurus borealis, Euderma maculatum, and Tadarida molossa were taken on too few occasions to determine the true habitats of the species. Lastonycteris nocti- vagans and Lasiurus cinereus, considered here as highland species, were taken at lower elevations during April, May, and June, but were more abundant at higher elevations in July and August. Vaughan and Krutzsch (1954) suggest a similar distribution for L. cinereus in southern California.
The seasonal distributions of each species of bats is summarized in Table 2. Four spe- cies (Myotis velifer, Lasturus borealis, Eu- derma maculatum, and Tadarida molossa) perhaps are represented by insufficient num- bers to give a valid indication of seasonal distributions of the species. Bats were most abundant in the study area during June and July (Table 2) and were least abundant during August. Females were more abundant than males in April and May, but males were slightly more abundant than females during the remainder of the season of study.
The range of time, expressed in minutes after sunset, in which each species was active is presented in Fig. 2. Three species (Myoztzs
Tulane Studies in Zoology
Vol=12
californicus, M. occultus, and Pipistrellus hesperus) were active mostly during the first 1 hr and 40 min after sundown. Mum- ford (1964) and Cockrum and Cross (1964) present similar data for P. hesperus. Other species (Myotis evotis, M. subulatus, M. velifer, M. yumanensis, Lasiurus cinereus, Plecotus townsendu, Euderma maculatum, Antrozous pallidus, and Tadarida brasilien- sis) seemingly have a later period of ac- tivity, mostly after the first 1 hr and 40 min after sundown. The seven remaining species seem to be active during a period intermediate to the two aforementioned groups. The data indicate peaks in the ac- tivity of the animals during the first 2 hrs after sunset (Fig. 2). In only one case was predawn collecting successful.
Air temperature at capture is given for each species in Fig. 3. For those species where ten or more individuals are represented, a few general trends are suggested: Plecotus phyllotis was taken in a narrow range of temperature from 9 to 17° C, whereas Lasionycteris noctivagans (minus 2 to 20° C), Lasiurus cinereus (O to 22° C), and Tadarida brasiliensis (7 to 27 °C ) were active through a wide range. A high tem- perature preference, mostly above 20° C, was shown by Myozis vel'fer, Lasiurus bore-
TABLE 2. Numbers of bats of each species taken per night each month (number of bats collected each month divided by the number of nights bats were collected in each month). The total number of times bats were collected each month is given in parentheses
with the name of each month.
Total
July Aug.
April May June Sept. Oct.
taken (9) (7) (36) (2) (ali2}) (9) (1) Myotis velifer 3 .08 Tadarida molossa 1 .03 Lasiurus borealis 4 aA .08 Myotis occultus 66 1.08 .85 139 Plecotus phyllotis 31 BPA, .36 .59 Myotis californicus 22 29 .36 18 aPape Myotis subulatus 35 .66 .44 OU A) Myotis evotis 61 14 .36 1.18 41 I galal Myotis keenti 42 .44 .50 .28 a3) .44 Pipistrellus hesperus 3 Seve -O7 .69 78) .308 Antrozous pallidus 95 122 29 2.09 3212 cleat Myotis thysanodes 84 Le oll 1.16 alt AIUG .66 Myotis volans 226 00 14 PA Alyy 3.25 1.08 Biola Myotis yuwmanensis 137 .44 14 .30 MOT a6; KOR Plecotus townsendii 39 alta Sy) 30 silat Al Ge Tadarida brasiliensis 126 .08 a9 1.55 26 1.25 2.66 Lasiurus cinereus 191 .44 71.85 3.02 .70 BAP 1.00 Lasionycteris noctivagans 105 1.00 1.42 2.03 -29 .08 33 1.00 Eptesicus fuscus 277 44 aia 4.30 2.03 ag) 4.77 4.00 Total 66 6.16 6.00
1595 fic
21.47 12.92 26.22
No 4
alis, and Euderma maculatum; however, these data represent less than ten observa- tions each, and thus may not be meaningful.
DISCUSSION
The data presented in Table 1 provide an indication of the habitat of the various spe- cies of bats found within the study area. Inasmuch as the number of times collections MYOTIS CALIFORNICUS (14) MYOTIS EVOTIS (43)
MYOTIS KEENII (25)
MYOTIS OCCULTUS (24) MYOTIS SUBULATUS (24) MYOTIS THYSANODES (22) MYOTIS VELIFER (3) MYOTIS VOLANS (183)
MYOTIS YUMANENSIS (9)
LASIONYCTERIS NOCTIVAGANS (85)
PIPISTRELLUS HESPERUS (29) (er
EPTESICUS FUSCUS (221)
LASIURUS BOREALIS (2)
LASIURUS CINEREUS (154) PLECOTUS PHYLLOTIS (24) PLECOTUS TOWNSENDII (12) EUDERMA MACULATUM (5) ANTROZOUS PALLIDUS (66)
TADARIDA BRASILIENSIS (45)
100
Bat Ecolog) 07
were made within each plant community and the number of localities from which collections were made varied, bats collected per station may be the least biased means of comparing habitats.
The great abundance of bats in the early part of the collecting season is due to the presence of relatively large numbers of fe-
RS ce cs ne meee _ com
_ oe rela
Pcs xi bo A ee ES
200 300
MINUTES AFTER SUNSET
Figure 2.
Range of time, expressed in minutes after sunset, in which each of 19 species
of bats was active. The horizontal line represents the range, the central vertical line indi- cates the arithmetic mean, the shaded area represents plus or minus two standard errors of the mean, and the unshaded area encloses plus or minus one standard deviation. For each species, the total number of bats for which data are available is given in parentheses. Time of sunset was corrected for latitude after being taken from tables furnished by the
United States Weather Bureau.
98 Tulane Studies in Zoology
males, whereas the numbers of bats present later in the season may be the result of premigratory or prehibernatory groupings of some species (Table 2). The abundance of certain species (Lasionycteris noctivagans and Lasiurus cinereus) early and again late in the collecting season is a reflection of movements of animals
migratory these MYOTIS CALIFORNICUS (14) MYOTIS EVOTIS (46) MYOTIS KEENII (25) MYOTIS OCCULTUS (24) MYOTIS SUBULATUS (20) MYOTIS THYSANODES (22) MYOTIS VELIFER (3) MYOTIS VOLANS (154) MYOTIS YUMANENSIS (8) LASIONYCTERIS NOCTIVAGANS (81) PIPISTRELLUS HESPERUS (29) EPTESICUS FUSCUS (220) LASIURUS BOREALIS (2) LASIURUS CINEREUS (153) PLECOTUS PHYLLOTIS (23) PLECOTUS TOWNSENDII (12) EUDERMA MACULATUM (5) ANTROZOUS PALLIDUS (66)
TADARIDA BRASILIENSIS (46)
Figure 3.
Volei2
through the study area (Findley and Jones, 1964). The small numbers of bats taken in the study area during August may have been caused by heavy rains during late July and August and resultant abundance of watering places. Observations during the rainy period indicated some decrease in num- bers of bats in areas where heavy concen-
10 20 30
TEMPERATURE IN DEGREES CG
Range of air temperature in which each of 19 species of bats was active. The
horizontal line represents the range, the central vertical line indicates the arithmetic mean, the shaded area represents plus or minus two standard errors of the mean, and the unshaded area encloses plus or minus one standard deviation. For each species, the total number of bats for which data are available is given in parentheses.
No. 4
trations were previously noted. Because of the increased availability of drinking water, bats probably were more widely dispersed during late July and August. Although water-hole samples of bats are considered herein as indicators of the entire community, it is realized that there is differential prob- ability in the capture of bats in mist nets (Cockrum and Cross, 1964).
Bats are well known for marked periodi- cites in their normal habits (Griffin and Welsh, 1937). During the summer, bats of the species considered here probably spend the day in roosts and emerge after sundown to seek food and water. Depending perhaps on the abundance of food and on temper- ature, bats may return to the roosts after a time or may forage throughout the night. Gould (1961) reported that light intensity and rain are important factors that influ- enced the time of emergence of Tadarida femorosacca, and suggested that temperature and total solar radiation during the day did not affect the time of emergence. Baker (1961) noted a general trend in the emer- gence of Tadarida brasiliensis from late times of flight in May to early times of flight in October. Analysis of the data pre- sented in Figs. 2 and 3 indicated that there is some correlation between air temperature and time capture of some species of bats. Members of one species, Myotis evotis, were active during a low range of temperature and were captured at time somewhat later than other related species, but for another species, Pzpistrellus hesperus, the converse was true. Some bats (Myotis yumanensis and Pzpistrellus hesperus) that were active during warm temperatures were taken either for a short period of time early in the eve- ming or were active for longer periods of time only when warm temperatures pre- vailed. Drinking and feeding activity of bats apparently is correlated with the air tem- perature. Any relationship of temperature to the time of emergence of the species con- sidered here is obscured by the nature of the data. The observations reported here do not permit speculation as to the distance bats may travel from roosts to watering areas and no evidence is available as to how soon after leaving the diurnal roosts bats approach water surfaces. Some bats may fly directly from roosts to water (Hayward and Davis, 1964), but other bats may follow an indirect route to water.
Bat Ecology 99
In general, the ranges of temperatures in which the species of bats were active coin- cide with distribution and habitat of the animals. The species (Plecotus phyllotis) that was active in a narrow range of tem- perature (9 to 17° C) is more limited in geographic distribution than those species (Lastonycteris noctivagans and Lasiurus cereus) that were active through a wide range of temperature (minus 2 to 20° C and 0 to 22° C). Myotis evotis, for which a low temperature preference was indicated (6 to 18° C), was not taken at low eleva- tions (below 7,000 ft) and Myozis velifer, M. yumanensis, and Prpistrellus hesperus, for which high temperature preferences were indicated. 62h to. 23° G 19 to 41° © and 14 to 29° C), were rarely taken at high ele- vations (above 7,000 ft). Preference for high temperatures suggest that some of the so-called lowland species of bats (Myotis velifer, M. ywmanensis, and Pipistrellus hes- perus) possibly are incapable of inhabiting highland areas, at least within the latitudes encompassed in this study. The converse may be true for the so-called highland form (Myotis evotis). On the other hand, the data indicate that some species (Lasionycteris noctivagans and Lasiurus cinereus), for which low temperature preferences are sug- gested, inhabit regions of high or low ele- vation and north or south latitudes con- cordant with season.
Activity of the bats included here, seem- ingly, was not affected by weather condi- tions, although Sheppard (1962) and Gould (1961) suggest that factors such as wind, humidity, cloud cover, and moonlight may influence the activity of bats. Wind and moisture seemed to influence only the num- ber of bats caught, not the number observed. On many occasions bats were seen drinking, flying about, and striking a net blown so tightly by the wind that no animals became entangled in the mesh. Several times bats were captured when foggy conditions pre- vailed and on a few occasions were taken during heavy showers.
Distribution of certain tree-roosting bat species is influenced by vegetation. For the other species of bats reported herein, few data are available to indicate any direct cor- relation between bat distribution and spe- cific vegetation. Distribution of bats per- haps is influenced by the availability of suit- able roosting sites, proper amounts of food
100
materials, and adequate water surfaces for drinking. Temperatures must be considered an important factor influencing certain ac- tivities and, perhaps, the distribution of bats.
SUMMARY
Of the 19 species of bats occurring in the study area, 13 species were collected in high- land areas (above 7,000 ft), six species were taken in lowland regions (below 7,000 ft), and one species was distributed equally in lowland and in highland areas. Only one species was restricted in distribution to a particular community.
Bats were most abundant in the study area during June and July. Females out- numbered males in the spring, but males were slightly more abundant than females during the summer and early fall.
Three species of bats were active during the first 1 hr and 40 min after sundown, nine species were active during a later period of time, and seven species were active during a period intermediate to the afore- mentioned groups.
Some species were taken in a narrow range of temperature (8° C); other species were taken in a wide range (20° C). Pref- erences for high temperatures were indicated by three species and preferences for low tem- peratures were detected for several species. The ranges of temperatures in which bats were active correlate with distribution and habitat of the animals.
ACKNOWLEDGMENTS
James S. Findley, Eugene Fleharty, David Niles, John Wright, Eugene Schroeder, Arthur Harris, and Dick Forbes either helped in the field or contributed specimens from the study area. I received financial assistance from the National Science Foundation dur- ing 2 months in each of the summers of 1958 and 1959, and for 3 months during the summer of 1960.
LITERATURE CITED
BAILEY, V. 1981. Mammals of New Mexico. N. Am. Fauna 53:1-412.
BAKER, J. 1961. What about bats? Carls- bad Caverns Nat. Hist. Assoc. 55 p.
Tulane Studies in Zoology
Vol. 12
CockruM, E. L., and S. Cross. 1964. Time of bat activity over water holes. J. Mam- mal, 45:635-636.
CoMMIssarIs, L. 1959. Notes on the Yuma Myotis in New Mexico. J. Mammal. 40: 441-442.
CONSTANTINE, D. 1961a. and notes on western bats. J. 42:404-405.
CONSTANTINE, D. 1961b. Spotted bat and big free-tailed bat in northern New Mexi- co. Southwestern Nat. 6:92-97.
FENNEMAN, N. 1931. Physiography of wes- tern United States. McGraw-Hill Book Company, Inc., New York. 714 p.
Locality records Mammal.
FINDLEY, J. 1960. Identity of the long-eared Myotis of the Southwest and Mexico. J. Mammal. 41:16-19.
FINDLEY, J., and C. JONES. 1964. Seasonal distribution of the hoary bat. J. Mammal 45 :461-470.
GOULD, P. 1961. Emergence time of Tada- rida in relation to light intensity. J. Mammal. 42:405-407.
GRIFFIN, D., and J. WELSH. 1937. Activity rhythms in bats under constant external conditions. J. Mammal. 18:337-342.
Harpy, E. 1941. Climate of New Mexico. In Climate and Man, Yearbook of Agri- culture: 1011-1024. U. S. Dept. of Agri- culture, Washington, D. C.
Harris, A. 1963. Ecological distribution of some vertebrates in the San Juan Basin, New Mexico. Musewm of New Mexico Press, Papers in Anthropol. 8:1-63.
HAYWARD, B., and R. DaAvis. 1964. Flight speeds in western bats. J. Mammal. 45: 236-242.
LowE, C. 1964. Arizona landscapes and hab- itats. In Vertebrates of Arizona. Univ. Arizona Press, Tucson. 132 p.
Mumrorp, R. 1957. Myotis occultus and My- otis yumanensis breeding in New Mexico. J. Mammal. 38:260.
Mumrorp, R. 1964. June bat records from Guadalupe Canyon, New Mexico. Souwth- western Nat. 9:43-45.
SHEPPARD, F. 1962. An annotated checklist of the bats of Bernalillo County, New Mexico. M.S. Thesis. Univ. New Mevxico. 101 p.
VAUGHAN, T., and P. KruTzscuH. 1954. Sea- sonal distribution of the hoary bat in southern California. J. Mammal. 35:431- 432.
ETHEOSTOMA (OLIGOCEPHALUS) NUCHALE, A NEW DARTER FROM A LIMESTONE SPRING IN ALABAMA
WILLIAM MIKE HOWELL and RICHARD DALE CALDWELL
Department of Biology, University of Alabama University, Alabama
ABSTRACT
Etheostoma (Oligocephalus) nuchale is described from 71 specimens collected from a limestone spring in the Black Warrior River system near Bessemer, Jefferson County, Alabama. FH. nuchale is known only from Glen Spring, the type locality, which is located above the Fall Line. It is compared to its nearest known relative, H#. swaini (Jordan), from which it is geographically iso- lated. E. swaini does not normally cross the Fall Line, and is a wide-ranging species found along the Gulf Coastal Plain from the Ochlockonee River in Florida to the Amite River system of southeastern Louisiana and _ southern Mississippi. The species differ in de- tails of body proportions, squamation, pigmentation, development of lateral line and cephalic sensory canals, cer- tain fin-ray counts and habits.
On 21 March 1964, Dr. Ronald A. Bran- don and Ron Altig collected three specimens of an undescribed darter while dip-netting for salamanders in Glen Spring at Bessemer, Jefferson County, Alabama. On 24 March 1964, we visited the spring and obtained 51 additional specimens. This distinctive spe- cies differs consistently from its nearest known relative, Etheostoma swaini (Jordan), in details of body proportions, squamation, pigmentation, development of lateral line and cephalic sensory canals, certain fin-ray counts, and habits.
Counts and measurements were obtained by methods defined by Hubbs and Lagler (1958: 19-26) unless otherwise noted. Techniques of Hubbs and Cannon (1935)
were used in making measurements to the nearest 0.1 mm. Proportional measurements are expressed as thousandths of the standard length.
We wish to thank the following individ- uals who have aided us in this study: Dr. Ronald A. Brandon and Ron Altig of the University of Southern Illinois first collected specimens of this handsome new species and made them available to us; Dr. Herbert T. Boschung, Jr., our major professor, con- tinually encouraged us and gave many help- ful suggestions; Dr. Ralph Chermock of the University of Alabama criticized our manu- script in its early stages; Dr. Ralph Yerger of Florida State University permitted us to examine his unpublished data on Etheostoma swaint and also made radiographs for us; Dr. Royal D. Suttkus and John S. Ramsey of Tulane University made available to us a collection of the species described herein; Dr. Reeve M. Bailey of the University of Michigan criticized the final draft of our manuscript and made many. helpful sug- gestions.
Etheostoma nuchale, sp. n. Watercress Darter CEig: 1)
Material—The holotype, University of Michigan Museum of Zoology, UMMZ 187523, an adult male, 39.4 mm in standard length, was collected by us on 24 March 1964 in Glen Spring at Bessemer, Jefferson County, Alabama (NE'4 SEY Sec 17, T 19S, R 4W) along county highway 20. In
EDITORIAL COMMITTEE FOR THIS PAPER:
REEVE M. BAILEY, Curator of Fishes, Museum of Zoology, University of Michigan,
Ann Arbor, Michigan
ROYAL D. SUTTKUS, Professor of Zoology, Tulane University, New Orleans, Louisiana
RALPH W. YERGER, Professor of Zoology, Department of Biological Sciences, Florida State University, Tallahassee, Florida
101
102
the same collection we obtained the follow- ing specimens: the allotype, UMMZ 187524, an adult female 39.8 mm in standard length; 20 paratopotypes, UMMZ 187525; 20 para- topotypes, U. S. National Museum, USNM 259800-F1; and 9 paratopotypes, University of Alabama Ichthyological Collection, UAIC 1227. Twenty paratopotypes, Tulane Uni- versity No. 34591, were collected on 9 Sep- tember 1964 by Dr. Royal D. Suttkus, John S. Ramsey, and Francis L. Rose.
At present this species is known only from the type locality in the Black Warrior River system of Alabama.
Diagnosis—A species of Erheostoma of the subgenus Oligocephalus (Bailey and Richards, 1963) distinguished by: lateral
line incomplete, moderately straight; supra- temporal canal incomplete; infraorbital canal usually incomplete; nape naked mesially; top of head, breast, and prepectoral areas naked; cheek largely naked but always with few to several embedded or exposed scales
Tulane Studies in Zoology
Vol. 12
along posteroventral margin of eye; opercle with large exposed or embedded, ctenoid scales; body scales large, with 35-42 scales in the lateral series; 12-24 pored scales in lateral line; branchiostegal membranes mod- erately to narrowly conjoined, sometimes overlapping anteriorly. Fin-rays: dorsal VIII to XI (usually IX or X), 10 to 12; anal II (rarely III), 6 to 8; pectoral 11 or 12. Nape distinctly humped, usually decurving sharply to occiput. Breeding adults with a sub- marginal red band in spinous dorsal fin. Description—A moderately robust species with body slightly compressed; snout mod- erately pointed to somewhat rounded; pec- toral fin shorter than head length; 11 to 14 branched caudal rays; 15 to 17 scale rows around caudal peduncle, of which 6 to 8 (usually 7) are above the lateral series and 6 to 8 (usually 7) are below; transverse scales are 10 to 12 (counted from origin of second dorsal fin posteroventrally to anal fin base); supratemporal canal incomplete,
Figure 1. Top. Etheostoma nuchale, sp. n. Adult male holotype, 39.4 mm in standard —
leneth (UMMZ 187523).
Bottom. Etheostoma nuchale. Female allotype, 39.8 mm in standard length (UMMZ
187524).
No. 4 A New Darter 103 TABLE 1. Comparison of Proportional Measurements of Etheostoma nuchale and E. swaini! erase: As Thousandths of Standard eee Species = Etheostoma nuchale Eine eicnes swaini
Museum number UAIC 929, UAIC UMMZ UMMZ UMMZ UMMZ 1112,1113, 1060,1090, 187523 187524 187525 187525 1150,1162 1162,1180 Holotype Allotype Paratypes Paratypes and1184 and 1192 Sex M F M F M F Number of specimens it 1 10 10 10 10 Standard length, mm 39.4 39.8 384.9 36.6 35.9 37.3 (30.6-38.3) (27.1-45.2) (25.9- ve 7) (28.9-44.7) Head length 281 282 280 274 29 295 (264-293) varee 288) Ce 306) (270-313) Head width 167 164 176 171 162 1638 (164-188) (162-181) (148-176) (148-178) Snout length 53 48 52 51 5S 55 (45-61) (45-57) (43-60) (46-59) Orbit length 76 78 78 Han 85 87 (72-86) (67-88) (75-93) (79-96) Fleshy interorbital 61 50 59 54 55 57 width (54-62) (45-60) (50-63) (52-64) Upper jaw length U8) 78 13 Giz: 83 81 (60-82) (65-78) (76-92) (74-97) Lower jaw to juncture of gill membranes 134 118 128 22, 124 123 (110-152) (102-140) (115-1383) (114-135) Head depth at occiput 188 196 199 194 186 190 (193-216) (180-206) (172-200) (177-202) Body depth at dorsal origin 226 241 228 228 PCA 210 (212-238) (216-244) (196-231) (190-242) Body width 150 15S 148 148 142 152 (131-161) (132-162) (134-151) (1385-172) Longest pectoral ray 239 234 243 239 274 268 (231-255) (221-252) (249-301) (223-284) Pelvic fin length 206 204 220 210 224 214 (193-234) (187-2387) (191-239) (191-224) Pelvic fin base 38 38 37 35 40 35 (33-40) (33-37) (36-44) (31-39) Transpelvic distance 79 70 74 69 83 79 (69-78) (66-72) (80-86) (76-87) Interpelvic space 15 18 16 16 20 19 (13-20) (13-20) (14-23) (16-22) Pelvic insertion to juncture of gill membranes 180 191 186 180 190 LO9 (177-195) (172-195) (175-204) (170-218) Highest dorsal spine aL aly/ 123 145) 109 138 25 (113-141) (97-124) (128-154) (104-133) Highest dorsal soft ray 165 158 167 156 167 158 (153-179) (187-168) (151-180) (142-166) First anal spine 1) 78 85 74 85 80 (76-96) (67-97) (74-96) (69-93) Highest anal soft ray IZ 156 166 155 Ji LExy (154-177) (140-171) (187-166) (127-150) Caudal peduncle length 223 262 247 248 260 259 (235-263) (227-262) (234-282) (242-267) Caudal peduncle depth 127 118 lias} PL, 118 P15 (118-130) (102-130) (106-128) (108-129) Caudal fin length 195 211 216 221 230 22 (190-248) (191-246) (210-262) (202-246)
1 All specimens of E. swaini from the Black Warrior River system
104 Tulane Studies in Zoology Vol. 12 TABLE 2. Frequency Distribution of Fin-Ray Counts in Etheostoma nuchale and E. swaini! Dorsal Spines Soft Dorsal Rays Species VITL TEX x XI XII N Mean 1 alk ale} 18 N Mean E. nuchale 7 Sy ileal! 1 Gil Sale yet) ale} Bye alae, E. swaini 17 32 2 51 10.70 i) shal ie epee ILO Anal Spines Anal Soft Rays Species : Il 10 Ge N 6 tf 8 N Mean E. nuchale 50 1 51 3 41 i bile 0s FE. swaini 51 al 1133 35 3 51 ~=6.80 ae Total Pectoral Rays (both sides) Branched Caudal Rays s ala 22 23 24 25 26 27 28 29 N Mean 11 12 13 14 15 16 N Mean E.nuchale 16 4 31 Hil Seco Hd Ae, 44 18.30 EB. swaini Gf 8 8S. Boe al sal BHGil 3 12 24 5) aoe4beeiSaniG
1 All EB. swaini from Black Warrior River system * Atypical fin has count of III, 7
TABLE 3.
Frequency Distribution of Scale Row Counts in Htheostoma nuchale and E. swaini!
Scales In Lateral Series
Species = : a aul Be Bia Biel Tats aN Bie aes ie) ae wok ele ais aa N Mean E. nuchale AP 2Z SS se uke 0 4 1 i 51 Sule Oe FE. swaini ly = & 8 8 8 38 5 33 al 39.84 . 7 _ Seales In Transverse Series 10 ala ite, 13} N Mean EB. nuchale ye 23 5 Il 10.65 BE. swaini 2 35 183 al Hill 1 LAS ; 5 a 7 Scales Around Caudal Pedunele 15 16 iby 18 19 N Mean E. nuchale 9 40 2 51 15.86 EB. swaini 9 28 10 4 51 17.18 1 All EF. swaint from Black Warrior River system TABLE 4. (Continued on opposite page) Development of Lateral Line in Etheostoma nuchale and EF. swaini! So Pored Seales In Lateral Line Speci = ==, - a Deore 12°18 14 15 16 I1% 18 19 20 21 Sosa EF. nuchale 3 3 4 5 7 4 lh 8 1 7 — i i E. swaini : : ‘ Unpored Scales In Lateral Series ppeces 3.4 5 6 9% & -9 10 ii if “13 ae E. nuchale 4 il
BE. swaint 1 5 4 10 2 qf 5 5 2
1 All EF. swaini from Black Warrior River system
No. 4
with 2 pores on each side branch; lateral canal complete with 5 (rarely 4 or 6) pores; postorbital, coronal, interorbital, posterior nasal, and anterior nasal pores present; pre- operculomandibular canal complete with 10 pores; anterior portion of infraorbital canal separated from posterior portion in 85 per cent of specimens; infraorbital pores usually 3 + 5 (posterior plus anterior pores) but varies from 1 + 5 to 4 + 6 with several intermediate combinations. In two of 51 specimens the infraorbital canal is inter- rupted twice with pore counts of 3 + 1 + 4 and 2+ 1 + 3; one specimen has the canal interrupted three times with pore counts of 1 + 2 + 2 4+ 3; infraorbital canal com- plete with 8 pores in 15 per cent of speci- mens. The upper lip is bound to the snout by a well developed frenum; branchiostegal rays 6; vertebrae 34 or 35 (mean = 34.4) in counts made from radiographs of 15 specimens; holotype with 34 vertebrae; nuptial tubercles absent; genital papilla of breeding females is a short, blunt, somewhat conical tube; pored portions of lateral line conspicuous, being nearly devoid of pig- ment; humeral region beneath the semi- transparent opercular membrane is darkened; sexual dimorphism is pronounced; general body outlines are shown in Fig. 1. Body pro- portions are given in Table 1. In Tables 2-4, counts for the holotype appear in boldface.
Coloration—Sexual dichromatism is pro- nounced. Breeding males are brilliantly col- ored, breeding females are plain. The fol- lowing description is of the holotype, a breeding male. Notes were made immedi- ately after preservation. Five dark orbital bars are present on the head. A black bar which originates behind and just below the center of the eye extends backward and
A New Darter
105
slightly upward almost to the origin of the lateral line. This postorbital bar is broken immediately anterior to the upper portion of the preopercular margin. A_ preorbital dark bar which originates in line with the center of the eye extends abruptly down- ward and forward, passing just below the anterior naris; it then continues along the outer edge of the premaxillary frenum and ends on the upper border of the premaxilla. The lower lip is densely punctated with melanophores near its midline. A dark sub- orbital bar subequal in width to the pupil extends downward and slightly forward and ends on the interopercular margin. In the interorbital area is a very short supraorbital bar which begins on the iris slightly posterior to the mid-dorsal edge of the orbit and ex- tends about one-third the distance to the mid-dorsum. Halfway between the supra- orbital and postorbital bars is a dark bar which extends obliquely backward to the supratemporal canal at a 45 degree angle to the postorbital bar. The cheek and breast are light gray with distinct, evenly scattered, stellate melanophores. The isthmus and branchiostegal membranes are darker than the breast. There is no prepectoral spot; the melanophores at the pectoral fin base are widely and evenly distributed. The humeral region beneath the semitransparent opercular membrane is dark. The lateral line is without dark pigment, and forms a conspicuous light line. The pupil is blue- gray. The iris is metallic gold. Each body scale is margined with melanophores. A large dark spot is present in the center of most body scales giving an appearance of horizontal lines along the body (Fig. 1). The genital papilla and the region immedi- ately surrounding the anus is white. The
TABLE 4. (Continued)
Development of Lateral Line in Etheostoma nuchale and FE. swaini)
Pored Seales ia luatenal Line
26 27 28 29 30 381 32 33 35 36 37 38 N Mean 51 17.21
Oe oa) be. dey ae Sisal; ates Gales | 51 32.65
' Unpored Scales In Lateral Series a
7 948 19 -20 21 22 23 24 26 27 N Mean Ms) 8s 40. 8 BS 8 ie a 51 20.41 Bil 7.06
1 All FE. swaini from Black Warrior River system
106
belly is bright red-orange ventrolaterally. On the mid-venter the red-orange is broken by a narrow light stripe which extends from the anal area to the interpelvic region. The bright red-orange of the belly fades abruptly into light yellowish-white at the fourth scale row below the lateral line. There are six, poorly defined vertical bars best developed on their lower halves on the posterior half of the body. The bars are two to three scale rows wide, bluish-brown in color, and are separated by poorly defined orange bars. Ventrally the red-orange of the belly extends posteriorly uninterrupted to the middle of the anal fin base where it is broken by the first complete vertical bar. The nape has an irregular-edged, light yellow stripe which extends uninterrupted along the mid-dorsum from the base of the first dorsal spine to the occiput. There are seven highly irregu- lar dorsal saddles which are two to four times wider than the interspaces. There are three indistinct, black spots in a vertical series at the caudal fin base. Immediately behind the basicaudal spots are two large, round orange spots, one above the other. The orange spots extend a short distance onto the caudal fin. Except for the orange spots, the basal third of the caudal fin is blue; remainder of fin is clear. Melano- phores on the caudal fin are confined chiefly to the rays while chromatophores are on rays and membranes. The anal fin is bright blue. The pelvic fins are blue basally be- coming lighter toward the tips. The pectoral fins are largely clear, becoming light blue basally. Pectoral rays are evenly outlined with melanophores. Listed in sequence from fin margin to fin base, the first dorsal fin has the following color bands: (1) a mar- ginal blue band, (2) a submarginal red- orange band, (3) another blue band, and (4) a basal red band. Listed in like order, the second dorsal fin has the following color bands: (1) a wide marginal blue band, (2) a submarginal light orange band, (3) an intense red band, (4) a blue band, and (5) a basal red band.
In breeding male paratypes the coloration of the cheeks, breast, and prepectoral region varies from immaculate white to dark gray. The belly is light orange, red-orange, or bright red. Prepectoral spots are present or absent. Larger specimens usually have the nape mottled while most smaller specimens possess a conspicuous light stripe extending
Tulane Studies in Zoology
Volz
along the mid-dorsum from the base of the first dorsal spine to the occiput. A few specimens have a vertical red bar near the middle of the caudal fin. Patches of red pigment are sometimes present on the anal fin. Dorsal saddles are highly irregular, vary- ing in number from 4 to 9.
Females, in contrast to the brilliant nup- tial colors of males, are plain. Dominant colors in females are brown and black which contrast sharply with the white of the belly, breast, cheeks, and other light areas. Melano- phores are concentrated in the center of many body scales but do not produce hori- zontal lines as in males. The dorsum and sides of most females have interspersed black, brown and white spots which form no definite pattern (Fig. 1). Head colora- tion is similar to that of males. Five orbital bars are present. The nape is irregularly mottled in some specimens while most pos- sess a prominent predorsal light stripe. The prepectoral spot is present or absent. Dorsal saddles are usually highly irregular, varying in number from 3 to 9. The median fins have rows of discrete black spots on the rays. The black spots are boldly contrasted against the clear interradial membranes. The pec- toral fin rays are usually margined with melanophores while the interradial mem- branes are clear. The pelvic fins have me- lanophores on rays and membranes. The spinous dorsal is the only fin with bright color in breeding females, being similar to males but much subdued.
Habitat and habits—The type locality, Glen Spring, is a limestone spring which 1s- sues from the base of Glen Hill and forms a small, clear creek 2-9 feet wide and 2-18 inches deep. The creek flows into a man- made lake approximately 200 yards north of the spring basin. The estimated discharge of the spring at the date of collection was 500 gallons per minute. This flow is par- tially dependent upon recharge from local precipitation. The flow was greatly reduced during a long dry period in November 1964 but was restored December 1964, after the drought ended. The temperature of the spring varies narrowly between 16 and 18 degrees Centigrade. The elevation at the spring is 480-500 feet above sea level. Glen Spring is located within the small portion of the Valley and Ridge Physiographic Prov- ince which extends into the eastern part of the Black Warrier River Basin.
No. 4 A New
The outflow creek is choked with dense growths of watercress, Nasturtium officinale. The stream bottom consists of angular gravel in riffle areas and silt and mud in areas of reduced flow and heavy watercress growth. Etheostoma nuchale is very habitat specific; it is found only among the watercress. We have observed nuchale as it perched upon the leaves and roots of watercress at mid- water depths. There it feeds upon the abundant snails, crustaceans, and insect lar- vae which inhabit the spring and outflow creek. In aquaria, nwchale moves about freely, perching here and there upon roots and leaves of aquatic plants. It does not normally inhabit the bottom as do most darters. E. nuchale can be collected almost anywhere along the stream course above the lake. It is absent below the lake where the stream becomes heavily polluted. The stream below the lake runs into Halls Creek which flows through a residential section of Besse- mer, Alabama.
We have collected in other springs in the Birmingham-Bessemer area but have not taken nuchale. Most of the springs have either been exploited for public or industrial water supplies or have otherwise been al- tered. Glen Spring is located approximately twenty yards off the present Jefferson County Hwy. 20. The outflow creek closely parallels the highway. E. nuwchale is in dan- ger of extinction on the basis of its limited habitat alone. At present we are contem- plating the transplantation of muchale to other suitable springs in the area.
E. nuchale is abundant and very success- ful in the spring basin and outflow creek. Associates of nuwchale are, in order of de- creasing abundance, Semotilus atromaculatus (Mitchill), Lepomis cyanellus Rafinesque, Etheostoma whipplei artestae (Hay), and Campostoma anomalum (Rafinesque ).
Darter 107
Relationship —Etheostoma nuchale is ap- parently a highly specialized derivative of E. swaini (Jordan), from which it is geo- graphically isolated. E. nuchale is known only from the type locality which is above the Fall Line in the Black Warrior River system of Alabama. FE. swatnz normally does not cross the Fall Line and is a wide-ranging species found along the Gulf Coastal Plain from the Ochlockonee River in Florida to the Amite River system of Southeastern Louisiana and southern Mississippi (R. W. Yerger, personal communication). We have made no attempt to study variation of E. swaini throughout its range as this problem is currently being investigated by Dr. Ralph W. Yerger of Florida State University. Since E. nuchale is such a distinctive species, it has been compared only with specimens of swaim from the Black Warrior River system (Tables 1-5). All specimens of swaini are deposited in the University of Alabama Ichthyological Collection and have the fol- lowing accession numbers: UAIC 677, 679, 929, 1060, 1112, 1113, .1150, 1161, 1162, 1180, 1192, 1225, 1582, all from Tuscaloosa Co., Ala.; UAIC 1184 and 1190 from Fayette Co., Ala.
Breeding males of nuchale and swaini have the same basic color pattern with the colors being more intense in nuchale. Fe- males of nwchale and swaimi differ markedly in color pattern: in swam there are dark spots in the center of most body scales which usually produce definite horizontal lines along the body (Fig. 2); in nachale there are many darkened scales but horizon- tal lines are not usually developed (Fig. 1). Other color differences are also apparent.
Seventy-three per cent of 51 specimens of swaini had either embedded or exposed scales on the nape. In nwchale the nape is always naked mesially.
TABLE 5.
Comparison of Etheostoma nuchale and
E. sw aini}
Character
; jae Wenale
E. swaini
Supratemporal canal Infraorbital canal
Pored lateral-line scales Unpored lateral-line scales Dorsal spines
Total pectoral rays
Scales in transverse series Scales around caudal peduncle
15-17 (x 15-86)
Widely interrupted Complete Usually interrupted Complete 12-24 28-38 15-27 3-11 VATTEXT (Ge -91'2,) D,GU (Ge ILO (0) 22-24 (X=) 23229) 24-29 (X = 25.61) Usually 10 or 11 Usually 11 or 12
1All E. swaini from Black Warrior River system
108
Tulane Studies in Zoology
Vol. 12
Figure 2. Top. Etheostoma swaini. Adult male, 41.8 mm in standard length, from
Black Warrior River system (UAIC 1184).
Bottom. Etheostoma swaini. Adult female, 44.7 mm in standard length, from Black
Warrior River system (UAIC 1090).
Body proportions (Table 1) as well as visual comparisons (Figs. 1-2) show that nuchale is much more robust than the slender, stream-dwelling swam. Since nuch- ale lives among dense growths of water- cress where water movement is very slow, the deep, robust body is probably a habitat adaptation. A distinctive feature of nachale is the humped nape which decurves sharply to the occiput. The humped nape does not seem to be associated with breeding activities since it is well-developed, even in juveniles of nuchale. It is absent in swarm. It is in- teresting to note that a few gravid females of nuchale were present in collections made from March through July. Under relatively constant environmental conditions of the spring, the breeding season of muchale may be extended. We suspect that swamni of the Black Warrior River system breeds in early spring.
The following characters of nuchale probably represent increased specialization over those of swaini: (1) reduced number of pored lateral-line scales, (2) incomplete
supratemporal canal, (3) incomplete infra- orbital canal, (4) reduced number of pec- toral rays and dorsal spines, (5) increased sexual dimorphism and dichromatism, and (6) highly specific habitat. E. nuchale has probably evolved, as an isolated population, in response to relatively constant conditions encountered in the spring environment.
Name.—tThe specific name, nuchale, “pet- taining to the nape’, calls attention to the light predorsal area and to the humped nape. The vernacular name, “watercress darter,” is suggested in reference to its habitat.
LITERATURE CITED
BAILEY, R. M., and W. J. RICHARDS. 1963. Status of Poecilichthys hopkinsi Fowler and Etheostoma trisella, new species, Per- cid fishes from Alabama, Georgia, and South Carolina. Occ. Papers Mus. Zool. Univ. Mich., 6380: 1-21.
Hupss, C. L., and M. D. CANNON. 1935. The darters of the genera Hololepis and Villora. Misc. Publ. Mus. Zool. Univ.
Mich., 30: 1-98.
SGANS. oA RS UL eee and K. F. LAGLER. 1958. Fishes of the Great Lakes region. Cran- brook Inst. Sci. Bull. 26: xiii + 218 p.
————a
October 11, 1965
EARLY DEVELOPMENTAL STAGES OF THE ROCK SHRIMP, SICYONIA BREVIROSTRIS STIMPSON, REARED IN THE LABORATORY!
HARRY L. COOK and M. ALICE MURPHY,
Bureau of Commercial Fisheries, Galveston, Texas, U.S. A.
CONTENTS Page I. INTRODUCTION Eee eae eS oe ERE RRO NT OP ea Ce Eee Cee ED 109 Il. METHODS AND MATERIALS _ 110 III]. DESCRIPTION OF STAGES 110 iN, TER a ea lee ee a eee SO 110 NG AUT CaS 0 Sa eSB 0 ee ee ee a ee 110 Gee TTS) TG He en NE ee INauplins Ws <A ss oe ea Pep Namplius lV 20 as tS lal 121 “ISTE Sd Seep aae ei a ane ed leah 52 eA A ee SOM Re ade eA, ele AR IE a GreProtozocale se ea 12 H. Protozoea II __ LS eroro7Ocatile Ae 5 ty tare es Seal 2 Wa ea ee Sy Se ee lysisilt ces ee eee OE eS ae a eee oe ta eee NS iat) Lc [OUT 4S) ROT i SAE a A Ss flr gee EPPO AY eR ES Se ae 119 Aram Ny ESP IA ee oh a yg DO Sad Set ce oe 1:22 INeeeOstiahvak 92 ee ee 123 ne We EIRONOLOGY. OF LARVAL-DEVELOPMENT-2 222. ee 123 V. COMPARISON WITH DEVELOPMENT OF OTHER Sicyonia 123 RAE SUPNONMAR 1a a Ts Oe Se Oe See ee ae 126 Site DTP EERATURE GITEDs..... ¥en 126
ABSTRACT
Five nauplial, three protozoeal, four mysis, and the first postlarval stages of the rock shrimp, Sicyonia brevirostris Stimpson, reared from eggs spawned in the laboratory, are described and illustrated.
1 Contribution No. 203, Bureau of Com- mercial Fisheries Biological Laboratory, Galveston, Texas.
I. INTRODUCTION
Fishery scientists at the Bureau of Com- mercial Fisheries Biological Laboratory in Galveston, Texas are studying the early life histories of Gulf of Mexico Penaeidae as part of an overall effort to establish relation- ships between the oceanic environment and the populations of commercially important shrimps. The effects of such variables as
EDITORIAL COMMITTEE FOR THIS PAPER:
WILLIAM W. ANDERSON, Laboratory Director, Bureau of Commercial Fisheries, U. S. Fish and Wildlife Service, Brunswick, Georgia
SHELDON DOBKIN, Assistant Professor of Zoology, Florida Atlantic University, Boca
Raton, Florida
ROBERT M. INGLE, Director of Research, Division of Salt Water Fisheries, Florida Board of Conservation, St. Petersburg, Florida
109
110
temperature, salinity, and circulation, as well as the success of spawning, cannot be accur- ately assessed until specific identification of the various larvae is possible. The larvae of penaeid shrimps, especially during the nau- plial stage, are remarkably similar, and least 13 penaeid species occur in the north- western Gulf of Mexico. To insure accurate identification of those larvae belonging to the genus Penaeus, the group of primary importance, we must also be able to distin- guish the larval stages of associated non- commercial penaeids. This report describes the early development stages of one of these species, Stcyonia brevirostris Stimpson.
Accoiding to Lunz (1957), 8. brevirostris occurs on the ea ae shelf of the west- ern Atlantic from just south of Norfolk, Virginia, around the Gulf of Mexico to Yu- catan. It appears to be confined inside the 50-fathom contour, reaching greatest abun- dance at 35 to 40 fathoms. At points throughout its range, this shrimp occurs in considerable numbers. It is not fished com- mercially, but since it has a very agreeable taste and attains a relatively large size, it is generally regarded as having potential com- mercial value.
Il. METHODS AND MATERIALS
All descriptions and figures are from speci- mens reared in the laboratory. Gravid fe- males were caught at sea and transported to the laboratory. Spawning took place in a fiberglass aquarium that contained 80 liters of aerated, noncirculating sea water. The lar- vae were then maintained in the aquarium until the first postlarval stage was reached. Cultures of a diatom, Skeletonema sp., were added as food at the first protozoeal stage and brine shrimp, Artemia sp., were intro- duced at the first mysis stage.
Temperatures during rearing varied be- tween 21.0° and 24.6° C. Salinity, which was 24.5%. at the start, rose to a maximum of 27.4%. The pH varied from 8.06 to 8.20.
Samples of larvae to be used for descrip- tive purposes were taken periodically and preserved in 5% buffered formalin. The un- stained larvae were illustrated with the aid of a Camera Lucida. Dissection of the ap- pendages was performed in formalin on a plastic slide.
The figures illustrating each substage de- pict an average larva. With the exception of the nauplial and protozoeal antennae, the
Tulane Studies in Zoology
Vole?
appendages on these figures are intended to show only relative size and position, not setation or segmentation. To illustrate mor- phological details that would otherwise be obscured, we rotated the antennae of the nauplial substages on their axes. Figures of the mouth parts and other appendages repre- sent a single appendage taken from one in- dividual. In order to present a clearer figure, the setules on the setae were usually omitted. Measurements are given in mm.
The following abbreviations are used in the text: TL = total length, including the rostrum but excluding the caudal spines; W = mean width at the point of greatest width; CL = carapace length, including the rostrum; N — number of specimens.
The adult from which the larvae were ob- tained was identified according to Anderson and Lindner (1943) and Lunz (1945). Both the adult and the larvae have been de- posited in the museum of the Bureau of Commercial Fisheries Biological Laboratory, Galveston, Texas.
III. DESCRIPTION OF STAGES A. Ege (Rios)
Viable eggs of S. brevirostris are round, golden brown in color, and translucent. Eggs measured soon after spawning were 0.23 mm in diameter. As the nauplius developed within the egg, the diameter increased to 0.27 mm just prior to hatching.
Go Va
Late eggs showing developing a. lateral view b. ventral view.
Hatching was observed only once. The nauplius filled the egg case and the furcal spines were already protruding when it was first noted. The nauplius appeared to flex, straightening out the first and second ap- pendages and pushing the eggshell off the anterior end of its body.
B. Nauplius I (Fig. 2)
Mean TL = 0.30 mm (0.28-0.32 mm) ; W = 017mm: N = 10
Nauplii of 8. brevirostris exhibit the pyri-
Figure 1.
nauplii.
No. 4
form body that is typical of all penaeid lar- vae thus far described. A blunt labrum is present on the ventral surface and a slight protuberance arises from the dorsal surface of the body.
An ocellus, which is retained in subse- quent nauplial substages, lies on the longi- tudinal axis of the body near the anterior end.
The posterior end of the body is rounded and bears a pair of spines.
Three pairs of appendages arise from the anterior portion of the body. The anterior ones (first antennae) are unbranched. The middle pair (second antennae) and third pair (mandibles) are branched into ventral endopods and dorsal exopods.
Setae arising from the appendages are smooth, but in succeeding substages the longer ones become plumose.
Color of the body and appendages is golden brown. The ocellus is black. Notes on color were not made for succeeding stages.
Setation of appendages:
First Antenna: Two short ventrolateral; a short spike and two long terminal; one long dorsolateral.
Second Antenna:
Endopod: Two short ventrolateral; two long terminal.
Exopod: Three long ventrolateral; two long terminal.
Mandible: Both branches bear three long setae.
C. Nauplius II (Fig. 3) Mean TL = 0.31 mm (0.29-0.34 mm) ; W = 0.18 mm: N = 7
The body is slightly more elongate than in the preceding substage. The posterior portion (edge) of the body between the single pair of caudal spines becomes flat- tened.
Setation of appendages:
First Antenna: Two short ventrolateral; one short, one long, and one medium termi- nal; one short dorsolateral.
Second Antenna:
Endopod: Two short ventrolateral; two long terminal.
Exopod: Three long ventrolateral; two long and one short terminal.
Mandible: Unchanged from Nauplius I.
D. Nauplius Ill (Fig. 4) Mean TL = 0.35 mm (0.32-0.37 mm); W = 0.18 mm; N = 26
Rock Shrimp. Development
EE
The body is more elongate than in Nau- plius II. Faint folds, the beginnings of ven- tral appendages, can be seen posterior to the labrum. The bases of the mandibles have become slightly swollen. A depression 1s present between the three pairs of caudal spines.
Setation of appendages:
First Antenna: One short and two me- dium ventrolateral; one medium, one long, and one short terminal.
Second Antenna:
Endopod: Two short ventrolateral; one short and two long terminal.
Exopod: Four long ventrolateral; long and one short terminal.
Mandible: Unchanged from Nauplius I.
E. Nauplius IV (Fig. 5) Mean TL = 0.37 mm (0.33-0.40 mm) ; W = 0.18 mm; N = 30
The body has become longer and the pos- terior portion more slender. The ventral ap- pendages that were first noted in the pre- ceding substage are more prominent, though still beneath the cuticle. These are the first and second maxillae and first and second maxillipeds. Two definite lobes have been formed at the posterior end of the body, each bearing five caudal spines.
Setation of appendages:
First Antenna: Two long and one me- dium ventrolateral; two long and one short terminal; one short dorsolateral.
Second Antenna:
Endopod: Two. short ventrolateral; one long and two medium terminal.
Exopod: One medium and three long ventrolateral; two long, one medium, and one short terminal.
Mandible: Unchanged from Nauplius I.
two
F. Nauplius V (Fig. 6) Mean TL = 0.44 mm (0.38-0.46 mm) ; W = 0.18 mm; N = 46
The body is further elongated and the fur- cal processes are more pronounced, each giv- ing rise to seven spines. The maxillae and maxillipeds are now external, and show more advanced development. The swelling at the base of the mandible, which has become large and prominent, possesses a masticatory surface composed of several rows of small teeth. Both the endopod and exopod of the mandible are frequently hollow and trans- parent. The outline of a developing carapace
112 2 ae “= == ASE, e e Se — a — Ce = ‘s ae —
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}, ia / \
Ol Figures 2-5, top to bottom. 2. Nauplhius I. a. ventral view b. lateral view. 3. Nauplius II, ventral view. 4. Nauplius III, ventral view. 5. Nauplius IV, ventral view.
Tulane Studies in Zoology
Vol. 12
can be seen on the dorsal surface of the body, and frontal organs are present on its anterior margin.
Setation of appendages:
First Antenna: Two short and one me- dium ventrolateral; two long, one medium, and two short terminal; two short dorso- lateral.
Second Antenna:
Basis: One short ventrolateral.
Endopod: Two medium and two short ventrolateral; one short and three long terminal.
——- Yaa ———— = | <= \ le J & ~ { ois — — > —_— Zz —— <a mon P <a ; ~ BEE y == AN Ws aN ‘ \\ ‘ oN \ \\ Wali \ Ol | B
Figure 6. Nauplius V. A. ventral view B. base of mandible.
Exopod: Four long ventrolateral; three long, one medium, and one short terminal. Mandible: Unchanged from Nauplius I.
G. Protozoeal (Fig. 7)
Mean TL = 0.81 mm (0.70-0.99 mm); mean CL = 0.33 mm (0.30-0.36 mm) ; N= 3
Body shape changes considerably with the molt to the first protozoeal substage. A large, loose-fitting carapace covers the an- terior section of the body. The posterior por- tion of the body has lengthened greatly and is now distinctly segmented. The maxillae and first and second maxillipeds are well developed and functional.
The carapace is rounded with a median notch at the anterior end, a pair of rounded frontal organs being the only protuberances on it. The ocellus, which persists in subse- quent protozoeal substages, is present be- tween a pair of compound eyes that are visible beneath the carapace. The labrum does not bear a spine on its anterior margin. Two lobes of the labium, bearing short bris- tles on their inner margins, can be seen pos- terior to the labrum. Several teeth of the
No. 4
inwardly projecting mandibles can be seen between the labrum and labium.
The first antenna is approximately twice the length of the endopod of the second an- tenna. It is composed of three major seg- ments. The basal segment, which is divided into five subsegments, bears one short seta. The second segment bears three setae, one short and one medium ventrolateral, and one
Rock Shrimp Development 1s)
short posterolateral. The disal segment bears three Jong and two short terminal, and one short posterolateral, setae.
The second antenna is composed of a two- segmented protopod, an endopod of two segments, and an exopod of from seven to nine, frequently indistinct, segments. The protopod bears one seta at the juncture with the endopod. The first segment of the endo-
Figure 7. Protozoea I. a. Ventral view ce. Maxilla I e. Maxilliped I b. Mandible d. Maxilla II f. Maxilliped II
114 Tulane Studies in Zoology Vol. 12
Figure 8. Protozea II. a. Dorsal view c. Maxilla II e. Maxilliped II b. Maxilla I d. Maxilliped I
No. 4
pod gives rise to a pair of setae from a point about one-third the length of the segment, and three terminal setae. The distal segment bears five terminal setae. The exopod bears five setae on its ventrolateral and two on its dorsolateral margins, as well as five term1- nal setae.
The mandible has lost both the endopod and exopod. The masticatory process 1s longer than in the last nauplial substage and curves inward, terminating in a ring of teeth.
The first maxilla consists of an unseg- mented protopod, a three-segmented endo- pod, and a small knoblike exopod. The pro- topod has two large lobes, each giving rise to several stout, toothed spines. The first and second segments of the endopod each bear two setae, and the third five. The exopod bears four setae.
The second maxilla is comprised of an unsegmented protopod, a three-segmented endopod and a small knoblike exopod. The protopod has five lobes on its ventral mar- gin, the basal lobe bears about seven setae and the remainder two to five. The first segment of the endopod bears two setae, the second and third, three; the exopod bears five.
The first maxilliped is longer than the maxillae and is biramous. It is composed of an unsegmented protopod, a four-segmented endopod, and an unsegmented exopod. The protopod has from 13 to 15 setae on its ventral margin. The first and third seg- ments of the endopod each bear two setae; the second, one; and the fourth, five. The exopod bears four lateral and three terminal setae.
The second maxilliped greatly resembles the first, although it is somewhat smaller. The protopod bears two setae. The first three segments of the endopod each bear one seta and the fourth bears five. The exo- pod has three lateral and three terminal setae.
The third maxilliped is small, biramous, and usually does not bear setae.
The slender posterior portion of the body is divided into six thoracic segments and an unsegmented abdomen. The abdomen term1- nates in a well-developed, forked, telson,
each lobe of which bears seven spines, the
outermost etxending inward across the furca.
Rock Shrimp Development
115
H. Protozoea Il (Fig. 8)
Mean TL = 1.23 mm (1.12-1.44 mm); mean CL = 0.44 mm (0.38-0.45 mm); NSS 28
The second protozoea is characterized by the presence of stalked compound eyes, a segmented abdomen, and a small rostrum which does not extend to the anterior edge of the body.
The frontal organs have been lost and do not reappear in later substages. Small pa- pillae which are present on the dorsoanterior margins of the eyes persist in the third pro- tozoeal substage.
Segmentation of the appendages remains almost unchanged from the preceding sub- stage. A dorsolateral seta has been added to the terminal segment of the first antenna. The number of spines on the second lobe of the protopod of the first maxilla has in- creased and an additional short seta is found on both the first and second segments of the endopod. Three setae have been added to the second maxilliped, one on the protopod and two on the endopod. Rudiments of five pairs of pereiopods are present posterior to the maxillipeds.
The abdomen is divided into six seg- ments with the telson still part of the sixth. The number of caudal spines remains con- stant at seven pairs.
I. Protozoea III ( Fig. 9)
Mean TL = 1.96 mm (1.84-2.09 mm); mean CL = 0.58 mm (0.54-0.61 mm); NI= 20
This substage can be distinguished from the second protozoea by the presence of biramous uropods and spines on the ab- dominal segments.
The rostrum has undergone slight elonga- tion and now extends slightly past the an- terior margin of the body.
The five subsegments which made up the basal segment of the first antenna in pre- ceding protozoeal substages have combined and three are now four segments. The first segment gives rise to one seta; the second and third, two; and the fourth, seven. In ad- dition to the two more prominent setae, a variable number of small setae now rim the distal portion of the third segment.
The second antenna, maxillae, and second and third maxillipeds remain essentially the same as in the preceding substage. The seta on the second segment of the endopod of
116
Figure 9. Protozoea III.
Dorsal view Maxilla I
a.
b.
Tulane Studies in Zoology
ec. Maxilla II d. Maxilliped I
e.
Maxilliped II
Vol.
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the first maxilla in the preceding substage has been lost. Such condition might indicate a variable number of setae on this segment. A second seta is present on the second seg- ment of the endopod of the first maxilliped. Although the pereiopods have developed further and are biramous, they are still non- functional.
Segmentation of the abdomen is more dis- tinct in this substage. Each of the first five segments bears a median spine on its dorso- posterior border. The fifth segment also has a pair of posterolateral spines, as does the sixth.
The telson is now separated from the sixth segment and each lobe retains seven caudal spines. A pair of biramous uropods originate from the ventroanterior margin of the telson. The exopod is slightly longer than the endopod and five or six setae arise from its apex. The endopod usually has two very small terminal setae.
J. Myszs I (Fig. 10)
Mean TL = 2.47 mm (2.16-2.66 mm) ; mean CL = 0.82 mm (0.74-0.89 mm); NeS 24
At the molt to the first mysis substage, the larva undergoes another fundamental modi- fication in body form, taking on a semblance of the adult for the first time. The trans- figuration is exemplified in the functional pereiopods with their long brushlike exo- pods, and by the transformation of the first and second antennae into the adult shape.
The carapace has a short rostrum that ex- tends slightly less than half the length of the eye. A single spine is found on the dor- sal carina of the carapace. Supraorbital and pterygostomian spines are present.
The ocellus and occular papillae persist in this and succeeding mysis substages.
The first antenna consists of three seg- ments. The first segment, which is about twice the length of the second and third combined, bears two spines, one on its me- dian margin, and one on its lateral margin. The distal segment gives rise to two branches; the lateral, bearing five or six setae, is three times as long as the median, which bears a single seta. A series of setae are present along the margins of the append- age, and numerous setae arise from the apex of each segment.
The second antenna is composed of a two-
Rock Shrimp Development
117
segmented protopod (the basal segment is not shown in fig. 10), an unsegmented en- dopod with two lateral and three terminal setae, and an unsegmented, flattened exopod which bears 10 setae along its median and apical margins as well as a single, subterminal, externolateral seta.
The mandible has undergone no appreci- able change. A short spine, added at the base of the second lobe of the protopod of the first maxilla, is the only difference. The exopod of the second maxilla has enlarged and now bears nine setae. An additional seta is present at both the apex of the protopod and on the endopod of the first maxilliped. The first and second segments of the endo- pod of the second maxilliped have each gained two setae, and two lateral setae have been lost from the exopod.
The third maxilliped and five pereiopods have become enlarged and possess long un- segmented exopods which bear six to eight setae. The protopod of the third maxilliped is unsegmented and bears four setae. Its en- dopod is composed of four segments, the first giving rise to one seta; the second, none; the third, three; and the fourth, five. The protopod of the first pereiopod is two-seg- mented with only a single seta present on the second segment. The endopod of the first pereiopod has been modified to form a rudimentary chela bearing three setae. The other four pereiopods were not examined in detail.
A ventromedian spine arises from each of the first five abdominal segments; the pleura, however, normally do not bear spines. Infre- quently, laboratory-reared mysis exhibited dorsoposterior spines on the fourth, fourth and fifth, or fifth segments. Since examina- tion of Szcyonia mysis from the plankton has failed to yield a specimen with dorsoposterior spines, their presence is tentatively regarded as an abnormal condition. The sixth seg- ment possesses a dorsomedian spine and a pair of posterolateral spines.
The uropod has developed an unsegmented protopod which bears a posteroventral and a posterolateral spine. The endopod and ex- opod are of equal length and bears numerous setae on their margins.
The telson, deeply cleft, bears six pairs of terminal and subterminal spines, and a single pair of lateral spines.
118
Tulane Studies in Zoology
Figure 10. Mysis I. a. Lateral view e. Maxilla II i. Maxilliped III b. Antenna I f. Maxilla II j. Periopod I c. Antenna II g. Maxilliped I k. Telson d. Mandible h. Maxilliped II
K. Mysis II (Fig. 11) Mean TL = 2.89 mm (2.70-3.15 mm); mean CL = 0.96 mm (0.90-1.05 mm) ; ING SS
A second spine is added to the dorsal carina of the carapace and there is now a well-developed antennal spine.
The first antenna remains unchanged, ex- cept that the developing statocyst can now be seen at the base of the appendage. The exopod of the second antenna now possesses a subterminal spine on its lateral margin and the number of median and apical setae has increased to 13.
The mandible bears a large unsegmented palp. An exopod is no longer present on the first maxilla, and a seta has been lost from the second segment of the endopod. The endopod of the second maxilla has become further enlarged and the number of setae has increased to 24.
The protopods of the three maxillipeds are composed of two segments. The terminal seta added to the protopod of the first max- illiped in the last substage is no longer present. The first segment of the endopod has also lost a seta. The endopod of the second maxilliped has gained a terminal seta.
Rock Shrimp Development
Wy.
Figure 11. Mysis II a. Lateral view Maxilla II i. Pereiopod I b. Antenna I Maxilliped I j. Telson
c. Antenna II d. Maxilla I
rm mo
A single seta has been added to both the first and second segments of the endopod of the third maxilliped. The chela of the first pereiopod now bears six setae. Rudiments of the branchiae are present as small lobes on the maxillipeds and pereiopods.
The addition of small unsegmented pleo- pods and a reduction in the width of the cleft in the telson represent the only major changes in the posterior portion of the body.
Maxilliped II Maxilliped III
L, Myses III (Fig. 12)
Mean TL = 3.51 mm (2.94-3.72 mm) ; mean CL = 1.13 mm (0.90-1.26 mm); N= 18
An additional spine added to the dorsal carina of the carapace raises the count to three.
The antenna have been modified slightly; the basal segment of the first antenna has gained a lateral spine apically, the endopod
Tulane Studies in Zoology
Volz
Figure 12. Mysis III. a. Lateral view e. Maxilla I i. Maxilliped III b. Antenna I f. Maxilla II j. Pereiopod I c. Antenna II g. Maxilliped I k. Telson d. Mandibular palp h. Maxilliped II
of the second antenna is now made up of three segments and its exopod bears 19 setae.
The mandibular palp, composed of two segments, has enlarged further. The maxillae remain essentially unchanged from the pre- ceding substage. Rudiments of the gills are present on the three maxillipeds and _ first pereiopod.
A seta has been added to both the first segment of the endopod and to the exopod of the first maxilliped. The endopod of the second maxilliped has gained an additional segment which does not bear setae. The dis-
tal segment of its protopod has lost two setae, leaving the protopod with one seta, while the exopod and the second segment of the en- dopod each have an additional seta. The endopod of the third maxilliped has gained a segment, making a total of five. The first three segments of the endopod now possess two setae each; the fourth segment, three; and the fifth, five. The exopod of the third maxilliped and of each pereiopod is now composed of two segments. The endopod of the first pereiopod is composed of four seg- ments, with the distal segment being the
No. 4 Rock Shrimp Development 121
rudimentary chela.
The posterior portion of the body has changed little. The pleopods, although now two-segmented, are still small. The cleft in the telson has become greatly reduced in size
and the position of the spines has changed. There are now four pairs of terminal and three pairs of lateral spines. The postero- ventral spine on the protopod of the uropod is absent.
Figure 13. Mysis IV. a. Lateral view b. Antenna I
c. Antenna II d. Mandible
rm mo
Maxilla I Maxilla II Maxilliped I Maxilliped II
i. Maxilliped III j. Periopod lI k. Telson
M. Mysis IV (Fig. 13)
Mean TL = 3.68 mm (3.48-3.81 mm) ; mean CL = 1.20 mm. (1.11-1.23 mm) ; NE= "10
The fourth mysis differs only slightly from the preceding substage. The addition of a fourth rostral spine and a reduction in the cleft of the telson represent the most promi- nent modifications. The antennae have also undergone changes, with the endopod of the first antenna now composed of two segments, and that of the second, five segments.
PAO Y — =
Tulane Studies in Zoology
Vol..12
The distal segment of the endopod of the first maxilla has lost a seta. The number of setae on the exopod of the second maxilla has increased to 36 and, although not shown in Fig. 13f, the setation of the protopod and exopod remains unchanged. The second and fourth segments of the endopod of the first maxilliped have each lost a seta, and the exopod, two. The number of setae on the protopod of the second maxilliped, and that of the second and fifth segments of its endopod, has increased and decreased by
Figure 14. Postlarva I. a. Lateral view e. Maxilla I i. Maxilliped III b. Antenna I f. Maxilla II j. Pereiopod I c. Antenna II g. Maxilliped I k. Telson d. Mandibular palp h. Maxilliped II
No. 4
one, respectively; its exopod is now two- segmented.
The pleopods retain essentially the same shape, but have increased in length and are now about one and one-half times the length of those of the previous substage.
N. PostlarvaI (Fig. 14)
Mean TL = 3.87 mm (3.51-4.35 mm); mean CL = 1.13 mm (1.07-1.21 mm); N= 2
With the molt to postlarva, the exopods are lost from the pereiopods and the pleo- pods, now heavily setose, are the principal swimming organs.
The rostrum is short, extending about one- half the length of the eye. The carapace usually bears four teeth on its dorsal carina, although some specimens show a small fifth spine anteriorly. Hepatic and antennal spines are present, the supraorbital and pterygosto- mian spines having been lost.
The ocellus persists, but the ocular papil- lae are no longer present.
Although there is no appreciable change in the first antenna, the endopod ( flagel- lum) of the second antenna is elongate and composed of 16 segments, while the exopod (antennal blade) is very broad at its base.
The mandibular palp has increased in size and bears about 20 setae along its margin. The endopod of the first maxilla is reduced greatly and is no longer setose. The endopod of the second maxilla is also vestigial, and the spines on the four lobes of the protopod are less prominent. The exopod has enlarged greatly and possesses about 60 setae.
Both the endopod and exopod of the first maxilliped are greatly reduced in size and setation. The second maxilliped retains a greatly reduced exopod, while the third maxilliped and the pereiopods have lost their exopods. The second maxilliped has be- come recurved and bears numerous spinelike setae on the last two segments. The dactyls of the chelipeds are fully formed. Although still rudimentary, the branchiae on the maxil- lipeds and pereiopods have developed two rows of small protuberances on their external surfaces.
The first five abdominal segments do not possess spines. The sixth segment has a small dorsomedian and a small pair of pos- terolateral spines.
The uniramous pleopods have lengthened
Rock Shrimp Development 12
ree)
and bear about 12 setae on the second seg- ment.
The protopod of the uropod retains a small posterolateral spine. The endopod and exo- pod are of equal length.
The telson is no longer cleft, ending in- stead in a blunt point. It bears five pairs of minute lateral spines and seven pairs of setae.
IV. CHRONOLOGY OF LARVAL DEVELOPMENT
Experiments by the authors with larvae of the brown shrimp, Penaeus aztecus Ives, showed that growth is closely related to tem- perature, becoming more rapid the warmer the water. Consequently, it is likely that the growth of S. brevirostris would also be ac- celerated at temperatures higher than those encountered during this rearing trial (21.0° to 24.6° C).
In this study, the eggs were spawned at night and hatched the following afternoon. Each nauplial substage lasted approximately 12 hours. The number of days after spawn- ing when the indicated substages were first noted are listed in Table I.
TABLE 1 Chronology of larval development Days after Substage spawning Protozoea I 3 Protozoea II 6 Protozoea III 10 Mysis I WW Mysis II 16 Mysist III ZZ Mysis IV 24 Postlarva 1 29
V. COMPARISON WITH DEVELOPMENT OF OTHER Sicyonta
As has been described, the larvae of S. brevirostris pass through five nauplial, three protozoeal, and four mysis substages before molting to the first postlarval stage. This sequence differs from that of the larval de- velopment of other (littoral) penaeidae in the northern Gulf area, most of which pass through only three mysis substages (Cook, in press), as well as from that of larvae of other Sicyonia spp. described in the literature (Table 2). One reason for the variation among descriptions by different authors may be that the number of substages is influenced by the environment in which the larvae grow. For example, Pike and Williamson (1964)
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126
found that under certain conditions, larvae of Pandalus montagui Leach reared in the laboratory passed through several additional zoeal substages before molting to megalopa. To ensure that the number of substages listed for S. brevirostris in this paper is the same as occurs in nature, and was not affected by the rearing procedure, a comparison was made with Szcyonza larvae in plankton sam- ples. The number of substages found in a large volume of planktonic material was the same as that found among laboratory-reared larvae.
Larvae of three other species of Szcyonia have been described: S. carinata by Heldt
1938); S. stempsoni by Pearson (1939); and S. wheeleri by Gurney (1943). Upon comparing descriptions of these larvae with specimens of S. brevirostris, we determined that in the protozoeal and mysis stages they possess morphological characters which per- mit their differentiation both from other penaeid larvae and from each other. Vart- ation between nauplii of different Szcyonza often appears to be as great as that observed between penaeid genera at the nauplial stage, and there seemingly are no definitive char- acters by which they can be collectively sepa- rated from nauplii of other genera. This is due to the fact that penaeid nauplii are very simple forms having the same general shape and relatively few setae, all of which mini- mizes the possibility of distinctive, inter- specific variation.
The following characters serve to distin- guish Szcyonta protozoeae from those of other penaeid genera: The first antenna is relatively long, about 114 times as long as the endopod of the second antenna, and bears three long terminal setae. The rostrum, when present, is very short with no supraorbital spines. The labrum does not possess a ven- tral spine, and the outer pair of caudal spines extends inwardly across the furcae.
The lack of dorsomedial spines on the first five abdominal segments is usually sufficient criterion for identifying Szcyonia myses. Other useful characters are the pres- ence of ventromedial spines on the first five abdominal segments, and the absence of hepatic spines on the carapace.
As pointed out by Heldt (1938), meta- morphosis among the Penaeidae is very grad- ual with relatively minor differences sepa- rating most substages. Because distinction
Tulane Studies in Zoology
Vol. 12
of successive substages can only be accom- plished somewhat arbitrarily, different in- vestigators examining the same kind of de- velopmental material might easily have dif- ferent opinions as to the number of substages represented. We believe this subjectively largely explains the variation in substage count recorded for Szcylonta larvae (Table 2). So, to facilitate comparison of the spe- cies described in Table 2, we have taken the liberty of placing the larvae of some authors in slightly different substage categories.
VI. SUMMARY
Five nauplial, three protozoeal, four mysis, and the first postlarval stages of the rock shrimp, Sicyonia brevirostris Stimpson, reared from eggs spawned in the laboratory, are described and illustrated. Temperatures during rearing varied between 21.0° and 24.6° C. Salinity, which was 24.5%o at the start, rose to a maximum of 27.4%. The pH varied from 8.06 to 8.20. Under these con- ditions, the larvae developed to the first post- larval stage in 29 days.
S. brevirostris larvae are compared with corresponding substages of three previously described species of Szcyonia. It was noted that the larvae of all four species possess characteristics which serve to distinguish them from one another.
VII. LITERATURE CITED
ANDERSON, W. W., and M. J. LINDNER, 1943. A provisional key to the shrimps of the Family Penaeidae with especial reference to American forms. Trans. Amer. Fish. Soc., 73: 284-319.
Cook, H. L., in press. A generic key to the protozoean, mysis, and postlarval stages of the littoral Penaeidae of the northwest- ern Gulf of Mexico. Fish. Bull. U.S. Fish. Wildlife Serv.
GURNEY, ROBERT, 1943. The larval develop- ment of two Penaeid prawns from Bermu- da of the genera Sicyonia and Penacopsis. Proc. Zool. Soc. Lond., Ser. B., 118: 1-16.
HELDT, JEANNE H., 1938. La reproduction chez les Cr ustacés Décapodes de la famille des Pénéides. Ann. Inst. Océanogr. Mona- co, 18: 31-206.
LuNz, G. Ropert, 1945. Carolina shrimps of the genus Eusicyonia. The Charleston Museum Leaflet No. 20, 12 p., Charleston, So (G:
, 1957. Notes on rock shrimp Sicyonia brevirostris (Stimpson) from exploratory trawling off the South Carolina coast. Contributions from Bears
No. 4 Rock Shrimp Development 127
Bluff Laboratories, No. 25, 10 p., Wadma- erus (Linn.). Bull. U. S. Bureau Fish., law Island, S. C. 49(30): 1-78.
PEARSON, JOHN C., 1939. The early life his- Pike, R. B., and D. S. WILLIAMSON, 1964. tories of some American Penaeidae, chief- The larvae of some species of Pandalidae ly the commercial shrimp, Penaeus setif- (Decapoda). Crustaceana, 6: 265-284.
October 11, 1965
7 : 7 a - 7
ea
does oe
i
4h
FISHES TAKEN IN MONTHLY TRAWL SAMPLES OFFSHORE OF PINELLAS COUNTY, FLORIDA, WITH NEW ADDITIONS TO THE FISH FAUNA OF THE TAMPA BAY AREA
MARTIN A. MOE, JR.
and GEORGE T. MARTIN, Florida Board of Conservation Marine Laboratory St. Petersburg, Florida
ABSTRACT
Monthly collections of fishes were made at nine stations offshore of Pinel- las County, Florida, from November, 1962, to June, 1968. Data on 2,317 fishes, representing 72 species, are re- ported. Occurrence of various species, relative abundance at certain depths and environmental descriptions are pre- sented. Growth and other biological da- ta are given for the 12 species most numerous in the catch. Salinity differ- ences were not considered significant since the observed range between high- est and lowest values was only 6%. Complete temperature data with a gen- eralized analysis are also presented. Distinctive differences in the fish fau- na at depth ranges of 15 to 18 ft, 25 to 45 ft, and 75 to 105 ft are demon- strated. Fifteen of the species collect- ed are new to the ichthvofauna of the Tampa Bay area. Another 27 species new to the area are included, although they were not taken during the study. The number of fish species reported from the Tampa Bay area is extended to 312.
INTRODUCTION
This account, with the exception of new additions to the Tampa Bay ichthyofauna, concerns the fishes taken during sampling for adult shrimp at established stations off- shore of Pinellas County from November, 1962 through June, 1963. This restriction limits the majority of the species listed to
* Current address: Bears Bluff Labora- tory, Wadmalaw Island, South Carolina. Contribution No. 93
the smaller, slow-moving bottom fishes. Data on 2,274 fish taken from November, 1962, through June, 1963 and 43 fish taken prior to this period at the same stations are included in this account. This is a relatively small number, but it represents one of the most extensive systematic collections from offshore stations in the Gulf of Mexico.
Since our study extended for only eight months, seasonal patterns exhibited by the fishes on their offshore range are not com- pletely disclosed. Sampling was conducted only at night and may have influenced the composition of the fish catch. Sampling was limited to one or two 15-minute trawls at each station using a 16-foot trynet (otter trawl). Obviously only a representation of the species present could be collected, thus these data are interpreted by species rather than by habitat. Effort at each station was not consistent because of inclement weather and unsuitable bottom for trawling. Some stations were trawled five times during the study and others were trawled up to 13 times. Except for one of the authors (Martin), the personnel and the vessel varied during the course of the study.
Certain factors limit the value of all sys- tematic sampling programs of offshore bio- topes. Most important is the extreme diffi- culty of repeatedly sampling exactly the same area. The problems of determining exact position at sea are well known and need no elaboration here. We are reasonably certain that all of our samples were taken
EDITORIAL COMMITTEE FOR THIS PAPER:
Harvey R. BULLIS, JR., Base Director, Exploratory Fishing and Gear Research Base, U. S. Bureau of Commercial Fisheries, Pascagoula, Mississipp1
GORDON GUNTER, Director, Gulf Coast Research Laboratory, Ocean Springs, Mis-
sissipp1
VICTOR G. SPRINGER, Associate Curator, Division of Fishes, U. S. National Museum,
Washington, D. C.
130
from the same general area at each station. Our certainty is based on compass headings, running time, approximate depth, and visual orientation points for most stations.
A primary work on the ecology of the Gulf fishes, conducted on the Texas coast, is by Gunter (1945). Many papers dealing with the biology of typical eastern Gulf of Mexico fishes of inshore, nearshore, or closely adjacent waters have appeared. The more extensive of these, in order of their geographic location from south to north, are: Longley and Hildebrand (1941) at the Tortugas Islands; Springer and McErlean (1962) at Matecumbe Key; Tabb and Man- ning (1961) at northern Florida Bay; Spring- er and Woodburn (1960) at Tampa Bay; Kilby (1955) at Cedar Keys and Bayport; Reid (1954) at Cedar Keys; Joseph and Yerger (1956) at Alligator Harbor; Miles (1951) at Apalachicola Bay; Bailey, Winn, and Smith (1954) at the Escambia River; Boschung (1957) at Mobile Bay; Gunter (1938) at Barataria Bay; and Darnell (1958) at Lake Pontchartrain. The locations of these studies are spaced over six degrees of north latitude and span approximately 1,000 linear miles of the Gulf of Mexico shoreline.
Systematic analyses of the fishes taken dur- ing commercial shrimping operations in various offshore areas for the Gulf are pre- sented by Hildebrand (1954 and 1955) and the Florida Board of Conservation
1951). These studies, especially those of Hildebrand, provide invaluable data on commercially important areas by listing the species present and their relative abundance in the catch. Even though very little hydro- graphic, seasonal, or specific habitat data were included in those studies, these papers form the bulk of our ecological knowledge of the shore fishes in the eastern sector, and offshore areas generally, of the Gulf of Mexico.
Springer and Woodburn (1960) contrib- uted significantly to our knowledge of the biology and ecological relationships of fishes in the Tampa Bay area. The present paper extends this knowledge into the offshore range of several species, thus complement- ing their extensive work.
STATION LOCATION AND DESCRIPTION
Most stations are within the region af- fected by tidal flushing of Tampa Bay. Each
station covered an area of one square mile
Tulane Studies in Zoology
Vol. 12
and, with a few exceptions (primarily the stations farthest offshore), all samples were taken within this boundary.
Two generalized bottom types were en- countered: a flat bottom of hard, fine sedi- ments isolated from any reef formations, and a flat bottom of coarse lightweight sediments in the immediate vicinity of limestone base reefs. The limestone reef environment is, ac- cording to Springer and Woodburn (1960), “one of the least known biocoenoses in the Gulf of Mexico.” Phillips and Springer (1960) reported on the algae typically found on these reefs and presented a physical de- scription of the general reef configuration. Springer and Woodburn (1960) and Moe (1963) also discussed the offshore reef en- vironment of this general area. These reefs were avoided as much as possible during our trawling, but as damaged nets testify, we were not always successful. Many of the fishes that appeared in Our nets are com- mon in the vicinity of these reefs: sparids, pomadasyids, sciaenids, and serranids. Small pieces of rocky reef, shell, and sponge were often taken in the nets also, thus we feel that we obtained many of the smaller fishes that dwell on or around the reef.
Stations 2, 3, 4, and 6 are the only sta- tions that veld fish each month of the eight-month period, and these stations are essentially the basis of our analyses. A total of 2,050 fishes, representing 90.1% of the fishes taken during the eight months, were trawled at the above stations. Stations 1, 7, 8, and 9 were not always fished and then only yielded fishes sporadically because of trawling difficulties. The production at these latter stations, 267 fishes collected in 14 suc- cessful trawl hauls, supplements the data from the four main stations. The stations are grouped according to the general depth range in which they occur to facilitate com- parisons. Stations 1 and 7 are respectively the shallow and deep extremes of the 1, 4, 6, and 7 grouping. Stations 8 and 9, though not thoroughly sampled, indicate extensive changes in the fish fauna of the deeper waters.
Stations 1 through 9 are mapped in Fig- ure 1 and the physical data for stations 1, 2, 3, 4, 6, 7, 8, and 9 are cumulatively pre- sented in Table 1. Stations 4, 6, and 7 are in an area that is frequented by commercial shrimp harvesters.
~
C ss eae ~. ® TARPON SPRINGS i. Kgmeacatl iS U 4 ;
Barod 10 fathoms = fathoms 7H | om
iS es pS aG Se GULF Ss ~ Pe (™~ oF Se MEXICO .
Figure 1. The Tampa Bay area and adja-
cent offshore waters. Numerals indicate the locations of stations 1 through 9.
STATION 1: 28°07’N 82°54°W
Station | is the northernmost station and is least affected by the discharge of Tampa Bay, although the discharge of the Anclote River creates the same general environ- mental conditions. This station is located about four miles from the Anclote Key light- house of an azimuth of 228°. Depths ranged from 18 to 30 feet, but almost all specimens collected were taken within a few feet of the mean depth of 23 feet.
Station 1 was trawled five times. Suitable bottom for trawling could not easily be found and this difficulty prevented consist- ent sampling. Trawls were generally made on a north-south axis whenever an area of flat bottom could be found. This station was especially destructive to our nets as they frequently caught on the bottom and were damaged. This was always the first station visited, thus our operations usually took place during the early hours of the night. Station 1 typifies the general bottom type of coarse lightweight sediments in the immediate vi- cinity of limestone reefs.
Station 1 was visually examined by the senior author with SCUBA gear to augment the fathometer recordings. These observa- tions were made during daylight on Novem- ber 19, 1963, on the northwest quadrant of
Offshore Fishes from Florida
the station. A flat bottom evenly covered with lightweight, coarse sediments mixed with a finer silt covered most of the area examined. This lightweight sediment layer (30 to 50 mm deep) could easily be dis- turbed and produced a dense cloud that settled in a matter of minutes. The sedi- ments became more compact and_ finer grained as they extended downward. The sediment surface was investigated to a depth of about 165 mm. Many small pieces of shell and coral were recognizable, and these became more frequent and larger as the sedi- ments graded into the rocky patch reef. There were one major and several minor patches of limestone rock reef in the area examined, a total of about 900 square yards of bottom. These rocky areas were 2 to 3 feet high and were very irregular with many cliffs, caves, and crevices. These reef areas were the center of almost all observed life. Attached invertebrates were profuse and formed much of the reef cover. Several large loggerhead sponges, Sphectospongia (vesparia?), were observed. One was measured and was ap- proximately four feet high and three feet across. Much of the general area offshore of Tarpon Springs has been described to a lim- ited degree by Dawson and Smith (1953) and de Laubenfels (1953) in conjunction with surveys on sponge disease.
Many fish were observed during the dive, but few of these were taken during the sam- pling at night. Larger serranids, sparids, and pomadasyids were seen most frequently.
STATION 23 27-5807 N82 DIO WwW,
This station is located due west of Clear- water Beach about one mile offshore of the surf line. The buoy lights of the ship chan- nel to the south and prominent shore lights allowed rapid orientation during night sam- pling. Depths varied from 15 to 20 feet.
Sampling conditions were always excellent at this station, thus a relatively large number of trawl hauls was made. Trawl hauls were made parallel to the beach, and always yielded many small fishes.
Station 2 typifies the general bottom type of a flat surface of hard, fine sediments 1so- lated from any reef formations. Visual ex- amination was made by the senior author during daylight on November 19, 1963, and the following observations were recorded. The bottom was hard, flat, marked with low ripples, and consisted of homogeneous sedi-
with a trynet unless otherwise specified.
Tulane Studies in Zoology
TABLE 1 Data summary for all stations from November, 1962 to June, 1963. All tows were made
Vol. 12
Station ie
bo
Salinity %o Surface Bottom Surface Bottom Taken
Depth Date No. of Tows (Ft.)
Nov. 14, 1962 1 24 Dec. 19, 1962 1 22 Jan. 15, 1963 il 18 Feb. 23, 1963 2 22 Mar. 18, 1963 0 25 Apr. 17, 1963 0 26 May 12, 1963 1(dredge) 28 June 4, 1963 1 24
TOTALS ai Nov. 14, 1962 1 18 Dec. 19, 1962 il aL Jan. 15, 1963 2, 16 Feb. 23, 1963 2 20 Mar. 18, 1963 2 aD Apr. 17, 1963 if 18 May 138, 1963 i 18 June 4, 1963 1 1H June 7, 1963 il 15
TOTALS 12 Nov. 15, 1962 i 18 Dec. 20, 1962 2 Lg Jan. 16, 1963 2, 19 Feb. 24, 1963 Ye 18 Mar. 19, 1963 2 15 Apr. 18, 1963 1 16 May 18, 1963 1 2; June 5,1963 il WPA June 6, 1963 il 15
TOWALS ie Nov. 15, 1962 1 30 Dec. 20, 1962 il 32 Jan. 16, 1963 1 30 Feb. 24, 1963 2 28 Mar. 19, 1963 2 30 Apr. 18, 19638 1 33 May 13, 1963 1 30 June 5,1963 il Zit June 6, 1963 1 PAL
TOTALS
= =
Discontinued prior to
Nov. 15, 1962 Dec. 20, 1962 Jan. 16, 1963 Feb. 24, 1963 Mar. 19, 1963 Apr. 18, 1963 May 13, 1963 June 6, 1963
| RRR Ree rPNe
S
34.4 33.4 34.5 31.2 32.1 35.0 34.9 36.7
33.2 32.3 35.1 31.8 32.1 34.5 34.9 36.1 36.0
32.6 33.5 34.8 32.8 32.8 34.5 35.6 36.6 36.1
33.6 34.0 34.7 34.0 34.0 35.9 36.8 56.8 36.1
33.1 33.4 35.5 33.5 34.8 36.8 36.9 36.3
34.4 33.8 34.8 33.4 32.8 34.7 34.9 36.3
33.4 33.4 34.4 32.9 32.5 34.0 35.5 35.8 35.7
32.5 34.1 35.1 33.0 33.2 34.6 36.2 36.6 36.6
34.6 34.6 35.7 34.4 33.8 35.8 37.0 36.8 36.0
35.5 34.7 36.0 33.3 34.3 35.7 36.8 36.3
No.
Temp. °C of Fish 17.8 17.8 5 see 12.4 17 1S yaa 1 5ek 5 14.6 14.3 14 ones 22.0 0 Pile 21-2 0 2Ar2 24.6 0 PAT 27.9 0 41 eA alyfes) 48 13.6 Wags) 195 Lass 15.4 119 14.6 14.4 32 24AE2 23.8 78 22.0 22.0 45 25.0 24.6 39 27.8 28.0 a — — 78 641 eg IWS) 34 13.6 ss 274 16.0 16.0 44 15.9 i525 35 23.8 Doel: 394 21.9 21.9 65 Zon0 Ps | TY 2Be2 28.5 3 28.3 28.5 61 927 18.6 18.6 Jot 13.6 NSe9 0 16.0 16.0 ale! 15.5 15.4 23 Zane, ZAlR5 68 Pall 2455 20 24.6 22.0 5 Pile 27.5 9 Pat les) 2020 PAU 174 18.4 18.4 10 14.5 14.6 105 16.2 M70 44 15.8 16.4 24 23.9 23.8 28 le, Zilad) 26 22.8 22.5 5 28.0 27.7 23 265
TOTALS
No. 4 Offshore Fishes from Florida 133 TABLE 1 (Continued) No. Depth Salinity %o Temp. °C of Fish Station Date No. of Tows (HE) Surface Bottom Surface Bottom Taken 7 Nov. 0 0 Dee. 21, 1962 2 42 35.0 Bia )oAl 16.1 IL {i Jan. 16, 1963 1 50 35.8 36.2 Ge 16.6 9 Feb. 24, 1963 re 50 34.5 34.6 16.0 16.2 4 Mar. 20, 1963 il 42 34.4 Bae Doel ZOE Zio Apr. 18, 1963 1 48 36.9 36.9 20.4 19.3 14 May 13, 1963 1 44 Bien 36.4 Dilez, Oso 0 June 5,1963 0 0 TOTALS 8 i 8. Nov. 0 0 Dee. 0 0) Jane Li, LIS i 70 36.8 3623 ee 183 33 Feb. 25, 1963 il 84 35.4 SO 16.4 16.6 4 Mar. 20, 1963 1 iz 34.8 34.7 22.4 18.3 0 Apr.18, 1963 1 81 36.8 36.5 Z0RS 18.3 3 May 14, 1963 1(dredge) 81 35.8 36.4 Zono 21.0 0 June 6, 1963 0 0 TOMAS 5 10 9. Nov. 0 0 Dee. 0 0 Jan. 0 0 Feb. 25, 1963 il 102 Soh 35.8 IO 17.6 i) Mar. 20,, 1963 1 100 36.1 36.0 Pilea, 16.2 0 Apr. 18, 1963 0 108 36.5 Sileo 21.0 19.0 0 May 14, 1963 1(dredge) 108 35.8 36.9 Drees Papa) @) June 6, 1963 Z 105 31.2 36.8 PAT AD Des 150 TOTALS 5 159 Total number of fish taken from all nine stations.............. 53 BOE ish) takenspriorato November 19 Gao. ee eee ee 43 TOTAL Dowel ment layers. The surface layer was very base, including parchment worm tubes,
lightweight and consisted of a brown, or- ganic, drifting material which was concen- trated in shallow depressions and between the crests of the bottom ripples. The primary sediment layer consisted of sand and bits of shell and coral which produced a silty cloud when disturbed and appeared to be of the same composition as, but more finely grained than, the analogous sediments of the first station. This primary sediment layer was about 50 mm thick and gradually graded into compact gray clay infused with par- ticles of shell. Approximately 600 sqaure yards were examined at the offshore edge of station 2. No fish were observed, but visi- bility was limited to about eight feet. The most abundant animal was an anemone, Anemonia sargassensis, which was attached to everything that offered a large enough
shells, sticks and other organic debris.
STADION 32227-43-N 82 45 WW
This station is located offshore of St. Petersburg Beach about one mile west of the surf line and offshore of the Don-Ce-Sar building. Depths ranged from 12 to 19 feet, although the extreme variations from the mean of 16 feet were usually not frequent.
This station was sampled most (thirteen 15-minute trawls, one more than station 2) and produced the greatest number of fishes. Trawling operations were conducted parallel to the beach, and depth was consistent dur- ing each haul. Trawling was always smooth and no rock or other irregularities were de- tected by the net or fathometer.
The topography of stations 2 and 3 are the same. These two stations represent the
134
same general habitat and are often grouped together in the analysis of data.
STATION 4: 27°39N, 82°52°W
This station is located about 234 miles due north of the entrance to the Egmont ship channel. Depths ranged from 27 to 33 feet and the mean depth was 30 feet. Little dif- ficulty was experienced in finding and trawl- ing this area.
This station had a bottom type intermedi- ate to stations | and 2. Reef formations were present, but of such low relief that trawling was not hindered. Although visual examinations were not attempted, fathom- eter recordings and net production suggest that the general bottom configuration con- sisted of hard flat sediments with occasional low rocky reef areas and patches of shell.
STATION =5527°397N 82° 56°30 WW
This station is located approximately 5 miles due west of station 4. It is most analogous to station 1, although it exhibits a greater extent of rugged limestone reef. Sampling was discontinued in June, 1962, because trawling was not feasible on the rugged bottom, and it is not part of our eight-month study. It is mentioned because it contributed a few specimens to our collec- tion before being discontinued.
SEATION: G6: 27° 34457N) 82°51-Ww
This station is located approximately 0.2 miles due west of Buoy R-2, at the mouth of the Egmont Ship Channel, on an azimuth of 253° from the Egmont Key Lighthouse. Depths ranged from 27 to 32 feet with a mean of 30 feet. Difficulties were seldom encountered during trawling operations. This station is most analogous to station 4 in depth and bottom composition, although there seemed to be fewer and less extensive patches of low reef and shell. For our pur- poses, stations 4 and 6 represent the same general habitat.
STATION -7: 27°35/N 82°56 W.
This station is located about 1 mile due west of the sea buoy of the Egmont Ship Channel. Sampling at this station began in December, 1962, and continued through April, 1963. May and June samples were not taken because of lack of suitable bottom for trawling. Depths ranged from 42 to 52 feet and the mean depth was 46 feet. Lo- cation was indefinite at these distant off-
Tulane Studies in Zoology
Vol. 12
shore stations since visual reference points were either vague or absent. Depth and run- ning time due west of the sea buoy were the criteria for station identification. Gross error in locating station 7 was avoided since the sea buoy was nearby.
Operational difficulties similar to those at station | were encountered. Depth varied during trawling to a greater extent at this station than at the others. Bottom contours recorded on the fathometer included slopes and reef formations. The physical descrip- tion of station 1 is generally applicable to station 7.
STATION 8: 27°35'N: 832070
This station is located about 20 miles due west of Egmont Key. Depth and running time from the Egmont channel sea buoy were the criteria for station location. This station was sampled once a month from January through May at depths ranging from 70 to 84 feet, and averaging 77.4 feet. The bottom type of station 8 appears similar to that of station 7.
STATION 9: 27°35°N.83 41s
This station is located about 30 miles due west of Egmont Key. Depth and running time were also employed to locate this sta- tion each month. Samples were taken during four moaths. Depths ranged from 98 to 108 feet and averaged 100 feet. The bottom type is basically similar to stations 1, 5, 7, and 8.
TEMPERATURE AND SALINITY
Salinity differences between stations dur- ing this eight-month period were not great enough to be considered significant. Surface salinities ranged from 31.2 “ec at station 1 in February to 37.2 “« at station 9 in June. Bottom salinities ranged from 32.8 “%o at station | in March to 37.5 “eo at station 9 in April. There was a difference of only 6.3 “ec between the highest and lowest re- corded salinity during the eight months of the study. The greatest range at any station, irrespective of surface or bottom reading, was 5.5 “%, at station 1 and the smallest range was 1.8 “%- at station 9. Salinity tended to gradually incrase from November to June and gradually increased and stabilized with depth.
Temperatures were generally lowest dur- ing December, ranging from 12.4°C to 16.1°C at stations 1 through 7. The highest
No. 4
temperatures were taken in June and ranged from 27.6°C to 28.4°C at stations 1 through 6. The greatest range between surface and bottom (4.2°C) was recorded at station 9 during June in 105 feet of water. At the shallow and mid-depth groups, stations 2 and 3, and stations 1, 4, 6, and 7, average surface and bottom temperatures did not vary more than 1°C during any one month. Temperatures were lowest in December, January and February, and rose sharply about 8°C in March. After a small drop in April, they rose steadily through June. Data are incomplete for stations 8 and 9, but the same general pattern of temperature change was present for surface temperatures. Bottom temperatures for this depth group did not fluctuate as rapidly as the shallow groups and lagged noticeably behind the surface readings during the spring temperature rise. All readings were taken at night.
METHODS AND MATERIALS
Trips were conducted on board chartered commercial fishing vessels. These vessels were all equipped with fathometers which were used in determining depth and finding trawlable areas. A 16-foot balloon trynet (otter trawl) was the basic gear used for the collection of shrimp and fish. Whiteleather (1948) stated that the balloon trawl is built to open high and full at the mouth allowing the net to take fish well off the bottom. Nets were constructed of tarred, number 15 Dura- cot twine tied at a 2-inch stretched mesh. The 3-foot cod end was constructed of 1-inch stretched mesh. The head rope or cork line included floats and measured 18 feet, and the foot rope or lead line measured 181 feet. These were attached to 30 by 15 inch wooden otter doors.
Hildebrand (1954) mentions that the fish- ing effort of otter trawls, measured in units of time per tow, is vague because the fish- ing characteristics of these nets have not been analyzed. However, some recent ar- ticles of analytical nature are based on ob- servations, measurements, and photographs of otter trawls in operation (Sand, 1959; de Boer, 1959; and Scharfe, 1959). It is still difficult to standardize otter trawl operations. Some variables that prevent units of time from being accepted as exact standards are, nonuniformity in rigging of the nets, vari- ation in net shapes, differences in weights affixed to the foot rope, speed and other
Offshore Fishes from Florida
variables of the vessels, and sweep of the net both empty and full. We kept our nets as standard as possible during the study to al- low a general comparison of effort on a unit of time basis. The foot rope was always weighted with chain rather than lead and whenever the net was changed due to loss or damage the same style of rigging was used. The net was always set on the surface off the stern and any fouling was cleared before the net was lowered. Evidences of proper operation were obtained through yields of large amounts of flora and fauna characteristic of the bottom habitat.
On three occasions a steel dredge, 37 inches long, 30 inches wide and 14 inches high with a 34-inch expanded metal liner was used when the bottom was too rugged to effectively use the trynet. The dredge was productive only at station 9, before the beginning of our eight-month study. This dredge sample yielded seven species of reef dwellers that were not taken at any other station.
Temperatures were determined im situ with a Whitney Underwater Thermometer Model TC 10 (Whitney Underwater Instru- ments, Box 521, San Luis Obispo, Cali- fornia) and later in the study with an Elec- trodeless Induction Salinometer Model RS-5 (Industrial Instruments Inc., 89 Commerce Road, Cedar Grove, Essex County, New Jersey). Before use of the salinometer, sa- linities were determined with calibrated sa- linometer bulbs (G. M. Manufacturing Com- pany, 12 East 12th Street, New York, New York) and the readings then corrected for temperature.
Specimens were preserved in 10% forma- lin. A representative sample of each species was retained after counting and usually after measurement when large amounts of certain species were taken in a single trawl. All fishes retained from these collections are deposited in the collection of the Florida Board of Conservation Marine Laboratory.
Fishes taken during the first 10 months of the offshore sampling program, when specimens were only casually collected for the laboratory's ichthyological reference col- lection, are also included in this account. These 43 fishes were taken with the same gear (15 by dredge and 28 by trynet) and at the same stations as those during the eight months of our study. Their inclusion supple-
136
Tulane Studies in Zoology
TABLE 2 Fishes taken in offshore waters of Pinellas Co., Florida
Mola?
Species
Gymnura nicrura Harengula pensacolae Synodus intermedius Bagre marinus Galeichthys felis Urophycis floridanus Centropristes melanus Diplectrum formosum Ephinephelus morio Serranus subligarius Serranus pumilio Lutjanus synagris* Apogon alutus Apogon conklini Apogon pseudomaculatus* EFucinostomus gula Haemulon plumieri Orthopristis chrysopterus Bairdiella chrysura Cynoscion arenarius Cynoscion nebulosus Equetus lanceolatus Leiostomus xanthurus Menticirrhus americanus Menticirrhus littoralis Micropogon undulatus Calamus artifrons Diplodus holbrooki Lagodon rhomboides Chaetodipterus faber Chromis enchrysurus* Toglossus calliurus Garmannia macrodon Scorpaena brasiliensis Scorpaena calcarata* Bellator militaris Prionotus pectoralis Prionotus roseus* Prionotus scitulus latifrons Prionotus tribulus crassiceps Astoscopus y-graecun Blennius marmoreus Ophidion beani* Otophidion grayi* Ophidion holbrooki Ophidion welshi* Lepophidium jeannae* Peprilus alepidotus Ancylopsetta quadrocellata* Bothus ocellatuso Bothus ocellatus* Citharichthys macrops* Cyclopsetta fimbriata*
byeto Se Stations 2
J Pwor| | |
> |
H
approximate depths
25’ to 45’
Stations 5 6
~
Tb! to Ob, Stations 8 9
Total
il! _
| bo
| ww
bo ees)
| }r}]a owl
I iw | eA]
| |
= |
Bel ele] wl]
>
es
be OS bet Boe BDO ReN RR Ww Wr Oo ww
vo OO el] HCO
i
—_ bob o1 OR ONHeNrF OO
No. 4 Offshore Fishes from Florida 137 TABLE 2 (Continued) approximate depths 15) tome? 254 tora? om towlone Stations Stations Stations Total 2 3 1 4 5 If 8 9 Etropus crossotus atlanticus Wa 114k — 19 — 21 — — — 65 Etropus rimosus* = = = SS sY/ 57 Paralichthys albigutta 8 = = = = it 3 = = 1 Syacium papilloswm* — 2 - - 8 -- — 67 ie Achirus lineatus* _ 1 — = 1 Symphurus diomedianus* — — — — 3 3 Symphurus plagiusa ao) 28 120 — 26 2, 3 - ale Gobiesox strumosus - ~ os 1 Alutera schoepfi ~ 2 — - = 2 Stephanolepis hispidus _ - 4 5 Lactophrys quadricornis 2 3 3 - = 1 -- - = 9 Sphaeroides nephelus il _ = — 1 Chilomycterus schoepfi 1 it — — i Diodon holocanthus* 2 = — = — —- = - = 2 Opsanus pardus ~ ~ 1 — — 1 _— — = 2, Porichthys porosissimus it 6 - 4 2 4 ~ 1 1 iy) Antennarius ocellatus — — _ - 1 - Byres 4 Ogcocephalus cubifrons 1 — — — — il Halieutichthys aculeatus* _ - _ - ~ — - 7 7 TOTALS 645 933 AT emilee 3 266 57 ie ee Pray [fate EFFORT (Number of 15- minute trawls during 8-month survey period) 12 ale Galil — 10 7 5 5 NUMBER OF SPECIES: by depth divisions 39 41 30 by station 30. 30 Si lis 7 Page BU 223
* Not reported from the Gulf of Mexico in the area of Tampa Bay by Springer and Woodburn (1960) during the period of their study, but recorded by them from Tampa
Bay, Old Tampa Bay, or Boca Ciega Bay.
** Including 43 fishes taken prior to November, 1962. *** Wishes taken by dredge June 5, 1962 (37.1 %o, 21.8°C)
ments the species taken during that period, although their data do not contribute to our species analyses.
Measurments were made on a standard l-meter fish measuring board, usually after the fishes had been in 10% formalin for several days. In instances when the catch was extensive, measurements were made aboard the collection vessel. Fork length (FL) was taken on fishes with forked tails and total length (TL) was taken on fishes with lunate or truncate tails. Standard length (SL) is given wherever possible to facilitate comparison with other studies, but it was
not taken consistently since it was not con- sidered an accurate field measurement on small fishes.
Tables and graphs are based on either TL or FL, although the approximate SL for each 3 mm grouping is also listed. These standard lengths were obtained from fishes that were retained and do not represent the entire number collected; thus they are considered approximate, but accurate enough for com- parative purposes.
SYSTEMATIC ACCOUNT
Nomenclature and phyletic family listing follow the presentation of the American
138
Fisheries Society (Bailey et al., 1960). Only bottom temperatures are mentioned in the text unless otherwise stated. Figure 2 iden- tifies the various graph symbols used in Fig- ures 3 through 5. The 12 species of fishes that were most numerous (89.4% of the total catch) are discussed individually, and Table 2 summarizes the data for all species.
Diplectrum formosum (Linnaeus ) ,
Sand Perch
This species, unlike Centropristes melanus which commonly dwells on the reef areas, is usually found on the sandy interstices be- tween reef formations. We collected 34 in- dividuals, 99 to 229 mm TL, distributed through every month and every station ex- cept station 8. The largest collection, five individuals, occurred in June at station 9. Stations 4 and 6 yielded 56% of our speci- mens of sand perch. The only evident dis- tributional pattern in regard to month or station was the occurrence of the largest fish on the stations farthest offshore, 7 and 9. Our data agree with the findings of Longley and Hildebrand (1941), Reid (1954) and Hildebrand (1955) who reported D. for- mosum from deep, sandy bottoms. This spe- cies is usually evident in the catches of party boats and during SCUBA diving excursions.
Orthopristis chrysopterus (Linnaeus ), Pigfish
This species was taken during every month and was the second most numerous fish, 376 individuals, in our total catch. Springer and Woodburn (1960) presented an extensive analysis of the occurrence of young pigfish in Tampa Bay during the course of their study. Our data (Figure 2) supplement theirs by extending the area of investigation into the offshore waters. The months of our largest collections were December through March. These months are the period of scar- city for species on the inshore grounds as both Springer and Woodburn (op. cit.) and Reid (1954) indicated. The size range of our November through January collections from stations 2 and 3 corresponds to the October through December collections of Reid (op. cit.) and Springer and Woodburn (op. cit.). Our data indicate that these fish, which apparently move to offshore locations, remain offshore and undergo more rapid growth with the advent of warmer temper-
Tulane Studies in Zoology
Volegi2 atures. The lowest temperature at which this species was taken was 12.5°C.
chrysopterus 1s common in the more northern and more saline coastal environ- ments of the Gulf. As Springer and Wood- burn mentioned, its abundance in shallower coastal waters decreases in southern Florida. Hildebrand (1955) commented that this species was common in 6 to 10 fathoms on the pink shrimp grounds in the Gulf of Campeche during February and July, and Tabb and Manning (1961) classified them as abundant in Joe Kemp-Conchie Channel during the cold winter of 1957-58. The pig- fish may be more abundant offshore than inshore in the southern regions of the Gulf of Mexico.
Bairdiella chrysura (Lacepede ) , Silver perch
This species was the third most numerous, 349 individuals, in our total catch. With the exception of four large specimens taken in deep waters, all silver perch were collected from our shallowest depth range, stations 2 and 3. Station 3, the sampling area nearest to Tampa Bay, produced 71.8°% of the total collected. B. chrysura was present in our collections during every month except May, but was poorly represented during April and February. Springer and Woodburn (1960) did not take this species in April and took only the very young during May; however, their gear was not effective for the larger fish. Spawning for this species probably takes place about that time as Springer and Woodburn (1960), Reid (1954) and Gun- ter (1963) took the first young of the year in May.
We assume that the paucity of specimens in our collections for April and May is due to a spawning migration to inshore waters. Springer and Woodburn (1960) concurred with Gunter (1945) that spawning takes place in the bays. Our June collection ts in- dicative of a return to the Gulf after spawn- ing. Four individuals from the June collec- tion were examined; two were gravid females (160 and 173 mm TL) with well-developed ova, and two were males (153 and 156 mm TL) in gross appearance, although sperm were not observed. This indicates that spawning may continue into June in the Tampa Bay area. The length and time of the spawning season may vary with annual me-
STATION |
LJ Se STATION 2 and 3
Figure 2.
teorological conditions. Tabb and Manning (1961) collected running ripe silver perch during late February in the Florida Bay area, and Joseph and Yerger (1956) mentioned collecting young in June and September. Gunter (1945) reported that B. chrysura spawns during rising temperatures and moves into the open Gulf waters in fall and winter.
Our data (Figure 3) illustrate that the November and the large December collec- tions approximate the size range of the speci- mens that both Springer and Woodburn (1960) and Reid (1954) took during those months. Growth in this first year class ap- pears to speed up as the water warms. Gun- ter (1938) suggested that the life history of this species is short and implied that sexual
Offshore Fishes from Florida
STATION 7
Monthly length-frequeney dis- tributions of Orthopristis chrysopterus.
PLUS 15 NOT MEASURED
JAN,
INCLUDING
FEB. ONE 226mm
STATION 4 and 6 mi STATION 8
STATION 9
maturity may be achieved during the first year. The normal life history probably spans only two annual cycles.
Leiostomus xanthurus (Lacepede) , Spot
A total of 35 spot was collected from De- cember through June. All of these, with the exception of three from station 6, were taken at stations 2 and 3. The collections for December and June represent 77.1% of total spot taken. Our specimens ranged in size from 125 to 205 mm TL. There were no tendencies toward monthly increments or regressions in size evident in our samples. L. xanthurus (particularly juveniles) is very abundant in coastal areas from Tampa Bay northward along the Gulf Coast. Bailey et al (1954) and Gunter (1963) recorded the
oO © fa) rm = UD =
Tulane Studies in Zoology
not
Jan. plus i2
N.-33
March
N.- 57
plus 61 not
measured
Vole
Figure 3. Monthly length-frequency distributions of Bairdiella chryssura. Graph legend as in Figure 2.
No. 4
young of this species from freshwater habi- tats, and Springer and Woodburn (1960), Kilby (1955), Joseph and Yerger (1956), and Miles (1951) all listed the spot as abundant in shallow waters. There is an ap- parent movement of young spot from in- shore to offshore waters as they grow, and Springer and Woodburn (op. cit.) postulated a late winter spawning and an offshore mi- gration in late summer for the Tampa Bay area. Spawning occurs primarily in Decem- ber and January along the South Carolina coast with two and three-year-olds as the principle spawners (Dawson, 1958). Gun- ter (1938) suggested that the life cycle of the spot is short. Our findings of only a rather small, randomly sized population of adult fish in the offshore waters during and several months after the peak of spawning agree with the findings of the above authors.
Menticurhus americanus (Linnaeus), Southern kingfish
This whiting was taken every month ex- cept November and May. Fifty-six percent of our 70 specimens were taken during December. All but seven individuals were collected at stations 2 and 3. Sizes ranged from 132 to 281 mm TL. The smallest fish was taken in January and the largest in April. As with the spot, no monthly size incre- ments or regressions were evident. The gon- ads of specimens collected in February were examined, but were not ripe and sex was not distinguishable. One female (280 mm TL, station 2) was found among the four fish examined from the March collection. The other three (208 to 214 mm TL, sta- tion 4) appeared to be males. One female (216 mm TL) and one apparent male (214 mm TL) occurred in the April collection at station 3, and one female (186 mm TL) and an apparent male (191 mm TL) from station 2 comprised the June collection. All females had well-developed ova.
M. americanus is uncommon in waters of low salinity and according to Hildebrand (1954, 1955) and Miles (1951) it is the common whiting of the open Gulf. Our data indicate that the adults are commonest in the open Gulf during the winter and that spawn- ing occurs from March to at least June. This agrees with Springer and Woodburn (1960) who suggested a May and June spawning at the time of their study, and Gunter (1945)
Offshore Fishes from Florida
141
who mentioned that this whiting leaves the bays in the winter.
Lagodon rhomboides (Linnaeus ), Pinfish
The pinfish is one of the most abundant and characteristic fishes along the coastal region of the eastern and northeastern Gulf of Mexico. This species was taken during every month except November and, although it varied greatly in monthly abundance, it was the most numerous fish (590. individ- uals) in our total catch. Our data (Figure 4) will be discussed only where it adds to the findings of Caldwell (1957) and Springer and Woodburn (1960).
Pinfish first appeared in our collections in December. This December collection was the largest single collection of any species at any time during our study. The 261 in- dividuals were taken at both the shallow and mid-depth stations with a strong pat- tern of size distribution according to depth evident. The size range of the smaller fishes (79 to 109 mm TL) from the shallower stations, 2 and 3, closely approximates the size ranges of the first year class collected by Springer and Woodburn (1960), Cald- well (1957) and to some extent Reid (1954). We believe this influx of pinfish at the shallower stations in December to be the migration of the first year class into the off- shore waters as Caldwell postulated an off- shore migration in cold weather, and Spring- er and Woodburn’s first year class diminishes in average size and number inshore after December. The size range of the fishes from the mid-depth stations 1, 4, 6, and 7 indi- cates the presence of the second year class in the deeper waters. Spawning is thought to take place offshore in the Gulf during the winter months and our findings place Cald- well’s first spawners, the second year class, in about 6 fathoms at this time. This second year class is no longer evident in our sam- pling after December, but few pinfish were taken in the following two months. We can- not adequately explain the sharp increase in numbers each third month of our study. No other species reflected this pattern of abun- dance. Growth apparently speeds up as the water warms since the size range of our June collection approaches those taken at the mid-depth stations in December. Dur- ing the March collection, 149 pinfish were discarded from the catch at station 3 before
142 Tulane Studies in Zoology Vol. 12 = OM ©ONNMO— OMOMNMO—-TROMODNHO—-TROM OP AW O-Th Se FF NN 0 COKEK RODD OO OO ——=N ANN ONS wees o-tsrKOmM in © OMmon _~tROMODNNO—-TROMO ie RRR ODDDDDOOCOLL2aANAMMMMYTTTNMNOO FL
_ NS 3 May ;
a N- 48 June
N- 87 March plus 149
not measured
-12 April
Figure 4. Monthly length-frequency distributions of Lagodon rhomboides. Graph leg-
end as in Figure 2.
measurement. These fish were within the size range of the 87 that were measured.
Prionotus scitulus latifrons (Ginsburg ), Leopard searobin
A total of 265 leopard searobins was col- lected. They were taken during every month with little variation in abundance. The larg- est collection occurred in March at the time of the strongest recruitment of young fish into our trawl catches. This subspecies 1s reported by Hildebrand (1955) as one of the most common and most characteristic fishes on the pink shrimp grounds off Cam- peche, and Springer and Bullis (1956) re- corded this species from 14 stations in the Gulf. Our data (Figure 5) also indicate that
this species strongly favors the offshore en- vironment. Table 3 shows 69.7% of our specimens were collected at mid-depth sta- tions. Springer and Woodburn (1960), Reid (1954) and Tabb and Manning (1961) did not take the leopard searobin in abundance during their studies, and the latter two papers report its occurrence adjacent to rela- tively deeper waters.
Our gear did not catch fishes smaller than 50 mm SL so the presence of fishes under this length would not be detected. Small in- dividuals appeared in our trawls of the mid- depth stations during February and March and were present through June. Fish from the February through June collections were examined for sexual development and _fe-
Offshore Fishes from Florida 143
9
th-frequency distributions of Prionotus scitul us latifrons. Graph legend as in Figure
Monthly leng
Figure 5.
144 Tulane Studies in Zoology Vol. 12 TABLE 3 Percentages of fishes taken at each depth range for the 12 most numerous species in the catch depths Total 15’ - 18’ 25’ - 45’ 75’ - 105’
Species Collected Percent Percent Percent Bairdiella chrysura 349 98.9 a2, 0 Leostomus xanthurus 35 91.4 8.6 0 Menticirrhus americanus 70 90.0 10.0 0 Lagodon rhomboides 590 88.1 Leg 0 Prionotus tribulus crassiseps 28 85.7 10.1 3.6 Orthopristis chrysopterus 376 82.2 17.5 3 Symphurus plagiusa Tal 54.0 43.4 Pall Etropus crossotus atlanticus 65 38.5 61.5 0 Prionotus scitulus latifrons 265 23-3 falend 0 Diplectrum formosum 34 14.7 70.6 14.7 Syacium papillosum hal 2.6 10.4 87.1 Etropus rimosus 57 0 0 100 Total number of fishes
taken at all depths 2317 1578 548 191 Percentage of total
number of fishes 68.1 Zou 8.2 Number of trawls
producing fish 66 PAS By 9 Percentage of the
total effort 13.6
a9 48.4
males with well-developed ova were observed in every month during this period. These females varied from 141 to 180 mm TL and were taken at both shallow and mid-depth ranges. The fish examined in February had well-developed ova; those fish examined from the March through May collections ap- peared to be nearing spawning condition; those examined from the June collection would extrude eggs upon pressure. Reid (1954) collected young fish (20 to 25 mm SL) in June, August, October, January, and May, a female in November with “slight ovarian development’, and a male in De- cember which “appeared to be near breeding condition.” Springer and Woodburn (1960) collected small fish in every month except December, 1957 and August, 1958. The in- flux of small specimens in our mid-depth trawls of February and March, apparent breeding conditions of adults from Decem- ber to at least June, and appearance of young fish at various times throughout the year 1n- dicate an extensive spawning season.
Prionotus tribulus crassiceps (Ginsburg ), Bighead searobin
Twenty-eight bighead searobins were taken, 27 during the eight months of sampling and one (233 mm TL) at station 6 in March of 1962. Two additional large fish were taken, one 228 mm TL at station 6 in November
and one 247 mm TL at station 8 in April. The remaining 25 specimens were collected at stations 2 and 3 every month from Febru- ary through June. These fish ranged in size from 69 to 113 mm TL. A trend toward in- creasing size was noted for each monthly collection.
Several authors, Miles (1951), Joseph and Yerger (1954), and Tabb and Manning (1961) reported this species as commonly occurring at inshore locations, and Hilde- brand (1955) considered it to be more abun- dant inshore than offshore. Our data, al- though limited, agree with this view since 85.7% of our specimens were taken at the shallowest stations.
Joseph and Yerger (1954) postulated a late summer and fall spawning and Gunter (1963) suggested a late fall and early winter spawning for P. tribulus tribulus. Hilde- brand (1954) found a nearly ripe female on the Obregon shrimp grounds (Texas) in early August. Springer and Woodburn (1960) found young fish from October through February in the Tampa Bay area. We first found small individuals of P. trzbu- lus at the same time of the appearance of small P. scitulus, February and March. These observations indicate that some spawning takes place in early fall, although spawning activity may extend over a greater period.
No. 4
Etropus crossotus atlanticus CRarn)e Fringed flounder
Fringed flounder were taken during every month for a total catch of 65 individuals. Total lengths ranged from 76 mm to 169 mm with the smallest fish taken in Novem- ber and the largest in April. The June col- lection, 22 specimens, represented 33.8% of the total catch of this species. Ripe fe- males were found every month from March through June and varied from 111 to 169 mm TL. The ovaries of fish from the June collection were turgid with eggs. Our data did not reveal any pattern of growth.
E. crossotus appears to be generally more common offshore than inshore. Hildebrand (1954, 1955) found it quite common in depths less than 17 fathoms offshore of Texas and Louisiana and on the Campeche Banks. Springer and Woodburn (1960) and Tabb and Manning collected very few, al- though it was common in the inshore collec- tions of Reid (1954), Joseph and Yerger (1956), Miles (1951) and Gunter (1938). The center of abundance of this fish appears to move farther offshore in the more south- er areas of the Gulf of Mexico. Reid (1954) found two young fish, 23 and 25 mm SL, in June and October, respectively, and postulated an “extended breeding sea- son during spring and summer.” Our data indicate that spawning takes place offshore from March until at least June, thus agreeing with Reid’s findings.
Etropus rimosus, (Goode and Bean), Gray flounder
Fifty-seven gray founders were collected, all during June and only at station 9. Total length ranged from 101 to 133 mm and were arranged in two well-defined group- ings which were probably composed of dif- ferent sexes. All the fish (10 individuals) examined between 101 and 118 mm TL, were ripe females; and all fish (5 individ- uals) examined between 124 and 133 mm TL appeared to be male, although no milt was observed. No other species in our col- lections, except Syacium papillosum, dis- played this sexual dimorphism of size. These data indicate an early summer spawning for this species.
E. rimosus is quite distinct from E. crossotus when comparative material is avail- able. Our specimens agree with the descrip- tion given by Longley and Hildebrand
Offshore Fishes from Florida
145
(1941). The snout of both sexes is covered with strongly ctenoid scales, and the pectoral fin on the ocular side is longer and larger than that of E. crossotws and has three to four horizontal, dark narrow bands which Longley and Hildebrand did not mention. The dark blotch on the lateral line just in advance of the dorsal and anal fin termina- tions varies from dark and well-defined to rather obscure. E. rzmosus has three dark blotches equally spaced along the lateral line, although the posterior blotch, about the size of the eye, is largest and most distinct. The scales of E. ramosus are strongly ctenoid on the ocular side and mildly ctenoid on the blind side, whereas scales of E. crossotus are mildly ctenoid on the ocular side and smooth on the blind side.
Springer and Bullis (1956) and Hilde- brand (1955) did not encounter this spe- cies, but Joseph and Yerger (1956) recorded it offshore of Alligator Harbor, and Briggs (1958) reported it from the southern At- lantic coast and the northeastern Gulf of Mexico. Evidently, E. rimosus is fairly un- common and restricted to the offshore waters of the eastern Gulf.
Syacium papillosum (Linnaeus ), Dusky flounder
Seventy-seven specimens were collected, and only 10 of these came from. stations inshore of station 9. S. papillosum was taken in every month except March and May. The largest collection of 59 individuals came from station 9 in June, and the smallest and largest fish (76 and 229 mm TL) were in- cluded in this sample. About half of this collection was examined for sexual develop- ment, and 14 ripe fish were found. The eight females were mildly distended with roe and varied from 137 to 175 mm TL. The six males strongly exhibited the sexual dimor- phic traits characteristic of the males of this species, 7.e., a cinereous blind side, two par- allel blue lines between the right eye and the snout area, and long filamentous exten- sions on the dorsal rays of the pectoral fin of the ocular side. Several smaller males with their external sexual characters not fully developed were also included in the collection. These data indicate an early sum- mer spawning, although activity may take place over an extended period. No growth
data were available through our collections. Longley and Hildebrand (1941), Hildebrand
146
(1955), and Joseph and Yerger (1956) all reported S$. papillosum from the offshore waters, and Springer and Bullis (1956) re- ported it from 36 Oregon stations in the Gulf of Mexico.
Symphurus plagiusa (Linnaeus ) , Blackcheek tonguefish
The blackcheek tonguefish was present every month, although it was rather scarce from December through February. A total of 113 specimens was taken from stations 1 through 8, but 54.09% came from the shal- lowest stations. Ginsburg (1951) considers it an inshore species since it ranges to only 14 fathoms. Our gear was selective for the larger individuals since most of the fish taken (124 to 174 mm TL) were wedged in the mesh of the net. Ripe females were found in the March through June collections and varied from 145 to 168 mm TL. Spawning appeared to occur in June; some of the fe- males examined from that month had flaccid ovaries with many free eggs.
S. plagiusa is common in the offshore waters in many areas of the Gulf (Hilde- brand, 1954, 1955; Gunter, 1945; Miles, 1951; and Joseph and Yerger, 1956) and the young are also occasionally taken in salini- ties below 7 “%o (Springer and Woodburn, 1960; Gunter, 1963). Hildebrand and Cable (1930) postulated a May through October spawning period based on the ap- pearance of juveniles off North Carolina. We agree with this concept of an extended spawning period since Gunter (1945) took a ripe female in April; Joseph and Yerger
(1956) found young fish in July; Tabb and tea (1961) reported taking small speci- mens of 20 mm (total length, we presume ) in March and September; Springer and Woodburn (1960) and Gunter (1963) re- ported their smallest tonguefish, 19 mm SL and 29 mm TL respectively, in October; and Springer and McErlean (1962) found 26 and 21 mm SL tonguefish in January and February respectively.
Table 2 is both a summary and analysis of each species present in our collections. We do not feel the need to comment on each species taken since the sparsity of our data in most cases would allow only occurrence to be mentioned. The stations are arranged by depth, shallowest to deepest. A summary of the effort expended and the number of species taken at each station and depth range
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is included at the end of the table. The 43 fishes taken prior to the eight months of the study are included in this table, and since they represent only 1.9% of the total fishes taken, they are not distinguished unless they were part of a dredge collection. Springer and Woodburn (1960) discussed distribu- tion and relative abundance of the species they observed in the Tampa Bay area. In Table 2, we have distinguished the species collected during our study that were not re- ported from the Gulf of Mexico by Springer
and Woodburn (1960) in their Tables 20 .
or 22. Some of these fish were reported from the bay environs, but not the Gulf.
Only three specimens of Urophycis flori- danus were taken, two in February at station 2 (92 mm SL) and at station 7 (114 mm SL) and one in March at station 4 (92 mm SL). According to Gunter (1945), Reid (1954) and Springer and Woodburn (1960), this species is found on the inshore areas during January through April. These in- dividuals are generally juveniles as were our specimens.
Eight specimens of Lutjanus synagris (05 to 110 mm SL) were taken during Novem- ber, three at station 2, four at station 3, and one at station 6. Another individual taken on September 13, 1962 (87 mm SL, 34.6 %o, 30.6°C) at station 2 augments our collec- tion to nine fish. Large individuals of this species are occasionally taken by party boats fishing the deeper waters during the sum- mer, and Hildebrand (1955) reported L. synagris to occur frequently on the Cam- peche Banks between 6 and 16 fathoms. Juveniles appear to move inshore during the fall of the year. Reid (1954), Springer and Woodburn (1960) and Tabb and Manning (1961) found L. synagris to be either pres- ent or abundant only during September to December.
Menticirrhus littoralis was collected only three times during our study. Two speci- mens, 160 and 165 mm TL, were taken in November at station 2, and one near-ripe female, 260 mm TL, was taken at station 3 in March. Springer and Woodburn (1960) found this species abundant in the summer at their beach station only one mile distant from our collection site. These fish, in their larger size ranges up to 169 mm SL, would have been more frequent in our trawls if they were present at the nearshore stations.
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Springer and Woodburn’s data indicate a spring spawning, probably May, and our data corroborate theirs. The winter habitat of M. littoralis remains unknown.
One specimen of Bellator militaris, 56 mm TL, was taken at station 3 in June. It was evidently a stray from deeper waters since this species is common in collections from 100 fathoms offshore of the lower west
coast of Florida.
Two species of Bothus were taken, B. ocel- latus and one recently recognized, but not named, which was identified by Dr. C. R. Robins. These fish were taken at both mid- depth and deep stations. Springer and Mc- Erlean (1962) probably took both species at their shallow water station in the Florida Keys, and Tabb and Manning (1961) did not record these species from the more in- shore area of Florida Bay. Hildebrand (1955) reported B. ocellatus as the commonest flat- fish on the Campeche Bank in 6 to 10 fath- oms in February, and common in 13 to 16 fathoms in July.
Citharichthys macrops was reported as very common on the Campeche Bank by Hilde- brand (1955), but Longley and Hildebrand (1941) only reported two specimens. This species was not rare at our mid-depth and deep stations. Two ripe females, 144 and 205 mm TL, were taken in March at stations 7 and 9. Spawning probably takes place in the spring.
One specimen of Gobiesox strumosus, 05 mm TL, was taken in a dredge sample at station 9 on June 5, 1962 (37.1 %o, 21.8°C). The collection of this individual offers a con- trast to Springer and Woodburn’s (1960) statement that this species is “strictly an inshore shallow water form.” G. strumosus was also reported from the Gulf by Springer and Bullis (1956) who recorded it at 16 and 25 fathoms.
One large specimen of Ogcocephalus cubi- frons, 267 mm TL, was taken at station 2 in June. Our identification is based on a simi- larity with the O. cubifrons of Longley and Hildebrand (1941) and the opinion of Springer and Woodburn (1960) that the common species of the Tampa Bay area is this form.
Dr. C. R. Robins kindly identified the Ophidiidae, Bothus, and Chromis enchrysu- rus; and Dr. Ernest Lachner graciously iden- tified the Apogonidae for us. All other iden-
Offshore Fishes from Florida
147
tifications are the responsibility of one of us (Moe).
DEPTH RELATIONSHIPS
It was not possible to ascertain the exact habitat from which each species was taken since our nets moved over a variety of bot- tom types and probably sampled several dif- ferent biotopes during each haul. As a re- sult, our analysis is restricted to the depth relationships of the 12 most numerous fishes in the total catch. Table 3 lists these fishes in order of their relative abundance at the shallowest stations. The depth preferences of these fish, within the limits of this study, are evident in Table 3.
The shallowest stations 2 and 3, produced the greatest number of fishes (68.1% of the total catch), although only 37.9% of the ef- fective effort (trawls that took fish) was expended at these stations. The mid-depth stations received 48.4% of the effective ef- fort and produced only 23.7% of the total catch. Our deep range, stations 8 and 9, was better balanced with 13.6% of the ef- fective effort producing 8.2% of the total catch. The mid-depth stations had their own characteristic fishes and also exhibited fringe populations of typical inshore and offshore species. Although the analysis is very gen- eral, it demonstrates the distinctness of the bottom fishes at various depths offshore of Pinellas County.
Gunter (1945, 1950 and 1961) showed that salinity can be correlated with size in marine fishes, although a direct relationship may not exist. Larger fish are generally found in higher saline waters, and conse- quently are found deeper and farther off- shore than smaller fish. Our data consist- ently exhibit the larger fish of most species occurring at the deeper stations. The salinity differential was probably too small to be significant in this distributional pattern. Depth then becomes one of the most obvious variables with a direct correlation to increas- ing size.
APPENDIX
During the course of this study, 15 species of fish were taken that have not been re- ported from the Tampa Bay area. An ad- ditional 27 species new to the area were taken in incidental collections since the pub- lication of the above papers, and these rec- ords are also listed here. Springer and Wood-
148
burn (1960) and Springer (1961) recorded 271 species of fishes from the waters of the Tampa Bay area. The number of species of fishes now known from the Tampa Bay area is 312. The specimens on which the fol- lowing records are based are deposited in the laboratory reference collection unless noted otherwise.
Carcharodon carcharias (Linnaeus). On February 10, 1965, a female white shark 11 ft. 10 in. total length was taken by the col- lecting crew of the Aquatarium with a 12 in. stretched mesh porpoise net. The capture occurred in four feet of water on a sand bar just offshore of Bunce’s Pass at the north end of Mullet Key. The animal was photo- graphed and discarded. There are two un- confirmed reports of white shark taken in the Tampa Bay area during the previous year.
Carcharinus obscurus (LeSueur). Springer (1961) reported two large specimens of Eulamia (Carcharinus) floridana stranded on a sand bar in Boca Ciega Bay on December 24 and 25, 1960. Garrick, et. al. (1964) demonstrated that these specimens were in- correctly identified and are actually C. ob- scurus, not previously reported from the Tampa Bay area by that name. Carcharinus falciformis (C. floridana) has not been taken in the Tampa Bay area.
Raja eglanterta Bosc. Two males, 490 and 540 mm TL, were taken with hook and line about 10 miles offshore of Clearwater Beach on February 2, 1963. Depth was 50 feet and bottom salinity and temperature were 33.8 “%o and 14.9°C. Since that time, three other specimens of the clearnose skate, two females and a male, have been taken from offshore waters in the Tampa Bay area.
Raja texana Chandler. One female, 378 mm TL, was taken in a large trawl from the R/V Hernan Cortez on December 21, 1964, at approximately 27°23’N, 83°20’W in 120 ft. of water. This specimen was taken in the same trawl haul as Bregmaceros atlanticus. Although the location is just suoth of the defined Tampa Bay area, these records are considered applicable since both species have been reported north and south of this region (Springer and Bullis, 1956).
Sardinella brasiliensis (Steindachner). One individual, 179 mm SL, was found in a box of frozen bait obtained from the Pinellas Seafood Company. The fish was captured in a commercial shrimp trawl in March of
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1964 about 8 miles offshore of Pass-a-Grille, Florida.
Saurida brastliensis Norman. Two speci- mens, 51 and 52 mm SL, were taken in 80 ft. of water due west of Egmont Key on De- cember 17, 1964. They were obtained in a dredge sample of the R/V Hernan Cortez.
Saurida normant Longley. One specimen, 273 mm SL, was taken in 20 fathoms at 27°52N, 83°37 W on April 20 19Gseae was captured with a 40-foot fish trawl dur- ing operations of the R/V Hernan Cortez.
Trachinocephalus myops (Forster). This species is common in the offshore areas of Pinellas County, but not nearly as abundant as associated species of Synodus. Our record is based on a specimen, 162 mm SL, taken by the R/V Hernan Cortez with a trynet on December 17, 1964, in 80 ft. of water due west of Egmont Key.
Ophichthus ocellatus (LeSuer.) One speci- men, 359 mm TL, was taken by Tom Stokel, a commercial bait shrimper, on January 23, 1964 on the south bank of Bunce’s Pass channel in the vicinity of the Sunshine Sky- way. It was captured in a frame trawl at about 2:00 A.M.
Bregmaceros atlanticus Goode and Bean. One specimen, 42 mm SL, was collected in a trawl haul on December 21, 1964, at 27° 23’N, 83°20'W in 120 ft: of waters feme= perature was 20.3°C (bottom).
Holocentrus bullisi Woods. One individ- ual, 123 mm SL, was taken on hook and line in 24 fathoms at 27°28’N on August 15, 1963 by a commercial grouper fisherman.
Rypticus arenatus Cuvier. Two specimens, 61 and 82 mm SL, were taken in 26 fathoms at 27°30’N, 83°48’W on May 24, 1965. They were captured in a 40-foot fish trawl during operations of the R/V Hernan Cortez.
Serranus phoeby Poey. One individual was collected in 32 fathoms at 27°31’N, 84° O1’W on May 24, 1965. It was taken with a 40-foot fish trawl during operations of the R/V Hernan. Cortez.
Pseudopriacanthus altus (Gill). One speci- men, 67 mm SL, was taken in a wire fish trap at 27°56’N, 83°81’W on March 30, 1965 during operations of the R/V Hernan Cortez. Depth was 18 fathoms.
Apogon psendomaculatus Longley. One individual, 52 mm SL, was taken at station 9 on June 5, 1962.
No. 4
Decapterus punctatus (Agassiz). Seven specimens (128 to 138 mm SL) were taken in a purse seine about 8 miles offshore of Clearwater Beach on June 17, 1964. Depth was 42 feet and surface salinity and tem- perature were 35.6 %« and 29.8°C.
Mullus auratus Jordan and Gilbert. Three individuals, 90 to 96 mm SL, were taken at 28°0S/N, 83°25’W in a commercial shrimp trawl on June 20, 1964. The haul was made at night at a depth of 80 feet. Surface sa- linity and temperature were 35.6 %o and 50°C:
Pagrus sedectm Ginsburg. One specimen, 317 mm SL, was taken by hook and line on May 23, 1963 about 65 miles offshore of Egmont Key. It was caught on a rocky bot- tom at about 25 fathoms.
Bellator militaris (Goode and Bean). One individual, 42 mm SL, was taken at station 3 in the June collection.
Prionotus ophryas Jordan and Swain. One specimen, 104 mm SL, was taken in 18 fath- oms at 27°406’N, 83°35’W on May 23, 1965, with a 40-foot fish trawl during operations of the R/V Hernan Cortez.
Prionotus pectoralis Nichols and Breder. One specimen, 81 mm SL, was taken in the March collection at station 4.
Opisthognathus lonchurus Jordan and Gil- bert. One specimen, 105 mm SL, was found in the spewings of a large red grouper taken in 25 fathoms at 27°42’N on May 23, 1963. The jawfish is in excellent condition and had evidently been ingested only a short while before the capture of the red grouper.
Kathetostoma albigutta (Bean). Three specimens, 70, 100, and 239 mm SL, were taken in the same trawl haul as the previous- ly Isted Rypticus arenatus and the same data apply to this record.
Dactyloscopus tridigitatus Gill. One speci- men was taken in a frame trawl by Tom Stokel on March 16 ,1965 in 4 ft. of water on the bay side of Egmont Key. A stand of Thalassia testudinum covered the sandy bot- tom.
Paraclinus fasiciatus (Steindachner ). One specimen, 39 mm SL, was collected in a dip met at the surface near the St. Petersburg Municipal Pier on May 31, 1963 by Tom Stokel. The Municipal Pier is located on Tampa Bay at about 27°46’N. Depth varies from 20 to 25 ft.
Offshore Fishes from Florida
149
Blennius nicholsi Tavolga. One individ- ual, 27 mm SL, was taken by W. K. Porter from near the dock on his property, 8430 Gulf Boulevard, St. Petersburg Beach, in August of 1963.
Ophidion welshi (Nichols and Breder ). Two individuals, 252 and 265 mm TL, were taken in December at station 7. Four other specimens of O. welshi were subsequently taken at stations 2 and 3.
Ophidion beani Jordan and Gilbert. One specimen was taken at station 7 in the March collection.
Otophidinm grayi Fowler. One specimen, 200 mm TL, was taken at station 7 in the March collection.
Lepophidium jeannae Fowler. One indi- vidual, 287 mm TL, was taken in the Febru- ary collection at station 9.
Psenes regulus Poey. Two specimens, 121 and 116 mm SL, were taken in 92 ft. of water due west of Egmont Key on December 16, 1964. They were collected with a large mid-water trawl operated from the R/V Hernan Cortez.
Bothus sp. (unnamed). Two specimens were taken during our study. One, 92 mm SL, was taken in January at station 6; and one, 80 mm SL, was taken at station 7 in April.
Bothus ocellatus (Agassiz). Two speci- mens were taken during our study. One, 51 mm SL, was taken at station 6 in December; and one, 97 mm SL, was taken at station 9 in June.
Cyclopsetta fimbriata (Goode and Bean). One individual, 216 mm SL, was taken at station 8 in February.
Etropus rimosus Goode and Bean. This species is discussed in the text of this paper.
Syacum papilosum (Linnaeus). This spe- cies is also discussed in the text of this paper.
Symphurus diomedianus (Goode and Bean). Three individuals, 153 to 154 mm SL, were taken in the June collection at station 9.
Symphurus minor Ginsburg. One speci- men, 45 mm SL, was taken in 80 ft. of water due west of Egmont Key on December 17, 1964. It was collected in a dredge sample from the R/V Hernan Cortez.
Symphurus urosplus Ginsburg. One speci- men, 160 mm TL, was taken in the same haul as the previously listed Muallus auratus and the same data apply to this fish.
150
Alutera heudelotu Hollard. Three indi- viduals, 174, 187 and 195 mm SL, were taken in 22 fathoms at 27°37’N, 83°43’W on May 23, 1965 with a 40-foot fish trawl during operations of R/V Hernan Cortez.
Lactophrys triqueter (Linnaeus). One specimen, 36 mm TL, was taken in a frame trawl on February 9, 1965 by Mr. Tom Stokel in 4 ft. of water on the Bay side of Egmont Key.
Halieutichthys aculeatus (Mitchill). Seven specimens were taken at station 9 in the June collection. One individual measured 80 mm TL and 49 mm disk width. All fish were about the same size.
SUMMARY
1. From November, 1962 to June, 1963 fishes taken during a study of adult pink shrimp offshore of Pinellas County, Florida, were retained for monthly biological analy- sis. These fishes were taken by a 16-foot trynet at monthly intervals from nine sta- tions. Gear was selective for the smaller, slow- moving bottom fishes. Few very young or relatively large fish were taken.
2. The stations have been grouped in general depth ranges. These are: stations 2 and 3, shallow, 15 to 18 feet; stations 1, 4, 6, and 7, mid-depth, 25 to 45 feet; and sta- tions 8 and 9, deep, 75 to 105 feet. Station 5 was discontinued before the detailed analy- sis of fishes was begun. Stations 2, 3, 4, and 6 produced 90.1 percent of the total catch. Data from the other stations are supple- mentary to these basic collections.
3. A total of 2,317 fishes representing 34 families and 72 species was collected at these stations. Twelve species composed 89.4 percent of the total catch and are dis- cussed in detail. The occurrence of the other species is presented in tabular form.
4. A difference of only 6 “%c between the highest and lowest salinity reading was re- corded during our study; thus, salinity 1s not considered a significant factor. Temper- atures ranged from 12.4°C in December to 28.4°C in June.
5. The largest individuals of each species were generally found at the deeper stations.
6. The depth relationships of the 12 spe- cies most numerous in the catch are analyzed. Definite depth preferences were found in most species within the depth range of the study, 3 to 18 fathoms.
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7. Fifteen of the 72 species taken had not previously been reported from the Tampa Bay area. These 15 species, along with 27 other species taken in incidental collections, are listed with data as new additions to the ichthyofauna of the Tampa Bay area. A total of 312 species of fish are now reported from this area.
ACKNOWLEDGMENTS
It is our pleasure to acknowledge the fol- lowing individuals for their contributions toward the completion of this paper. Mr. Vernon Senterfitt aided in the field work and in compilation of data and Mr. Phillip Heemstra assisted with the sorting and iden- tification of specimens. Doctors C. Richard Robins, Donald P. deSylva, and Victor G. Springer graciously reviewed the manuscript and offered valuable criticisms and sugges- tions toward improvement. Mr. Robert M. Ingle, Director of Research of the Salt Water Fisheries Division of the Florida Board of Conservation critically reviewed the manu- script and offered encouragement throughout the study.
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October 11, 1965
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