Life Sciences Contribution
Royal Ontario Museum 1 23
systematics, Osteology and Phylogenetic
Relationships of Fishes of the
Ostariophysan Subfamily Anostominae
(Characoidei, Anostomidae)
Richard Winterbottom
ROM
ROYAL ONTARIO MUSEUM LIFE SCIENCES PUBLICATIONS
INSTRUCTIONS TO AUTHORS
Authors are to prepare their manuscripts carefully according to the following instructions. Failure to do so will result in the
manuscript’s being returned to the author for revision. All manuscripts are considered on the understanding that if
accepted they will not be offered for publication elsewhere.
iE
GENERAL Papers for publication are accepted from ROM staff members, Research Associates, or from researchers
reporting on work done with ROM collections. In exceptional cases,monographic works on the flora and/or fauna of
Ontario will be considered for publication by authors not affiliated with the ROM. Authors are expected to write clearly
and concisely, and to omit all material not essential for an understanding of the main theme of the paper.
. FORMAT Manuscripts are to be typed double-spaced (including captions, synonomies, literature cited, and tables)
on 11’’ X 8%”’ paper with a 1%2”’ margin on all sides. Three xerox copies are to be submitted to the Chairman of the
Editorial Board, and the original retained by the author(s). A separate sheet is to be submitted giving author(s) names,
affiliation, title of publication, series in which it is to appear, number of typed pages, number of tables, and number of
figures. Manuscripts should normally be organized in the following order: Table of Contents, Abstract, Introduction,
Materials and Methods, Results, Discussion, Conclusions, Summary (if paper is long), Acknowledgements, Literature
Cited, and Appendices. Authors are encouraged to include foreign language translations of the Summary where
appropriate. Headings of sections are to be left-justified to the text margin. The first line of the first paragraph in each
new section should not be indented. Text-figures are referred to as ‘‘Fig. 1’’. Literature cited in the text is in the form
‘*Jones (1972)’’ or ‘‘(Jones, 1972)’’ or ‘‘(Smith, 1960:71-79, fig. 17)’.
. STANDARD SOURCES The primary source for decisions on format and style is A Guide for Contributors and
Editors of ROM Life Sciences Publications, available from the Chairman of the Editorial Board. Otherwise, consult
CBE (AIBS) Style Manual (3rd Edition). Other standard sources are as follows: for English spelling (Concise Oxford
Dictionary), for Canadian place names and coordinates (Gazetteer of Canada), and for spelling of geographic names
(Times [London] Atlas).
. ABSTRACT All papers are preceded by a short and factual abstract, about 3 per cent as long as the text, but not
longer than 400 words. The abstract is to be followed by four to six keywords enclosed in brackets.
. TAXONOMY The name of a taxon is given in full in headings, where it appears for the first time, or when the name
begins a paragraph. Use authority and date if appropriate, with first mention of each taxon and not thereafter.
Taxonomic papers follow the layout in Life Sciences Contribution 99, particularly the synonomies.
. LITERATURE CITED References in the text cite author and date and are enclosed in parentheses (Smith, 1978).
Complete references are listed in alphabetical order by author at the end of the paper. When there are two or more
citations for an author, the works are listed chronologically. Names of journals are not abbreviated. Consult Life
Sciences Contributions beginning with 117 for correct bibliographic form.
. TABLES All tables are numbered consecutively in arabic numerals in numerical order of their first mention in the
text. Mark the appropriate text location of each table with a marginal notation. Each table is typed on a separate sheet.
Avoid footnotes etc., to tables by building them into the title.
. FIGURES All figures are numbered consecutively in arabic numerals. Component photographs or drawings are
labelled sequentially in upper case letters. Mark the appropriate text location of each figure with a marginal notation.
The intended reduction for figures is ideally one and a half to two times. All labelling on figures is in blue pencil and
not inked or letraset. Halftones must be photographic prints of high contrast on glossy paper. Authors are to submit
10’’ x 8’ copies with the MS and retain originals until they are requested. Figure captions are to appear grouped
together on a separate page at the end of the MS.
LIFE SCIENCES CONTRIBUTIONS
ROYAL ONTARIO MUSEUM
NUMBER 123
RICHARD WINTERBOTTOM Systematics, Osteology and Phylogenetic
Relationships of Fishes of the
Ostariophysan Subfamily Anostominae
(Characoidei, Anostomidae)
ROM
ROYAL ONTARIO MUSEUM
PUBLICATIONS IN LIFE SCIENCES
The Royal Ontario Museum publishes three series in the Life Sciences:
LIFE SCIENCES CONTRIBUTIONS, a numbered series of original scientific publications including
monographic works.
LIFE SCIENCES OCCASIONAL PAPERS, a numbered series of original scientific publications,
primarily short and usually of taxonomic significance.
LIFE SCIENCES MISCELLANEOUS PUBLICATIONS, an unnumbered series of publications of varied
subject matter and format.
All manuscripts considered for publication are subject to the scrutiny and editorial policies of the Life
Sciences Editorial Board, and to review by persons outside the Museum staff who are authorities in the
particular field involved.
LIFE SCIENCES EDITORIAL BOARD
Senior Editor: J. H. McANDREWS
Editor: R. D. JAMES
Editor: C. MCGOWAN
RICHARD WINTERBOTTOM is Associate Curator, Department of Ichthyology
and Herpetology, Royal Ontario Museum.
| Canadian Cataloguing in Publication Data
Winterbottom, Richard, 1944-
Systematics, osteology and phylogenetic
relationships of fishes of the Ostariophysan
subfamily Anostominae (Characoidei, Anostomidae)
(Life sciences contributions ; 123 ISSN 0384-8159)
Bibliography: p.
ISBN 0-88854-252-6
1. Anostomidae. 2. Fishes - South America.
I. Royal Ontario Museum. II. Title. III. Series.
QL638.A568W55 Sed so C80-094 166-7
Publication date: 16 May 1980
ISBN 0-88854-252-6
ISSN 0384-8159
© The Royal Ontario Museum, 1980
100 Queen’s Park, Toronto, Canada MSS 2C6
PRINTED AND BOUND IN CANADA BY THE ALGER PRESS
Contents
Abstract |
Abstracto 1
Introduction 2
Materials and Methods 3
Systematic Section 4
Subfamily Anostominae (new concept) 4
Artificial Key to the Genera and Species of the Anostominae 5
Clave Artificial para los Géneros y Especies de los Anostominae 7
Anostomus (Gronow) Scopoli 1777 9
Anostomus anostomus (Linnaeus, 1758) 9
Anostomus brevior Géry, 1960 12
Anostomus intermedius sp. nov. 14
Anostomus plicatus Eigenmann 1912 16
Anostomus spiloclistron Winterbottom, 1974 18
Anostomus ternetzi Fernandez-Yepez, 1949 19
Genus Gnathodolus Myers 1927 21
Gnathodolus bidens Myers, 1927 22
Gnathodolus sp. 23
Genus Pseudanos gen. nov. 24
Pseudanos gracilis (Kner, 1859) 24
Pseudanos irinae sp. nov. 27
Pseudanos trimaculatus (Kner, 1859) 29
Genus Sartor Myers and de Carvalho 1959 31
Sartor respectus Myers and de Carvalho 1959 31
Genus Synaptolaemus Myers and Fernandez-Yepez, in Myers, 1950 33
Synaptolaemus cingulatus Myers and Fernandez-Yepez, in Myers, 1950. 33
Osteology Section 35
Introduction 35
Infraorbital Bones and Associated Elements 35
Suspensorium and Jaws 36
Hyoid Arch 39
Branchial Arches 40
Cranium 41
Weberian Apparatus 44
Pectoral Girdle 46
Pelvic Girdle 47
Dorsal and Anal Fins 47
Caudal Skeleton 47
Discussion 48
Infraorbital Bones 49
Suspensorium and Jaws 49
Hyoid Arch 51
Cranium 51
Weberian Apparatus 52
Pectoral Girdle 53
Caudal Skeleton 53
Acknowledgements 57
Literature Cited 58
Appendix 1. List of Material Examined 61
Appendix 2. Cleared and Stained Material 66
Appendix 3. Gazetteer of Localities Mentioned in the Text 67
Systematics, Osteology and Phylogenetic
Relationships of Fishes of the
Ostariophysan Subfamily Anostominae
(Characoidei, Anostomidae)
Abstract
The systematics of the South American characoid subfamily Anos-
tominae is reviewed on the basis of 36 morphometric and meristic
characters, and the osteology is described. A new genus, Pseudanos,
is described for a monophyletic lineage previously assigned to
Anostomus. Two new species, Anostomus intermedius and Pseudanos
irinae, are described. The subfamily consists of five genera, three of
which are monotypic. A hypothesis of the phylogenetic relationships
of the members of the Anostominae is presented, based primarily on
their osteology. The monotypic genera together form a monophyletic
assemblage. Zoogeographic interpretations are not attempted, since
vast areas (particularly in the central Amazon basin) are as yet either
not or inadequately sampled. Considerable distributional extensions
and discovery of new forms are to be expected in the future.
Abstracto
La sistematica de los Characoides Sud-Americanos (Caracoides),
subfamilia Anostominae es revisada en base a 36 caracteres
morfométricos y meristicos, describiendo también su osteologia. Un
nuevo género, Pseudanos es descrito en un lineage monofilético,
anteriormente asignado a Anostomus. Dos nuevas especies son
descritas: Anostomus intermedius y Pseudanos irinae. La subfamilia
consiste de cinco géneros, tres de los cuales son monotipicos. Se
presento una hipotesis de la relacion filética de los Anostominae,
basada principalmente en su osteologia. Los géneros monotipicos
forman en conjunto un grupo monofilético. Interpretaciones zoogeog-
raficas no son intentadas, ya que regiones muy vastas (especialmente
en la Cuenca Central del Amazona) no han sido aun, o solo
parcialmente estudiadas. Una distribuci6n extensional mucho mayor y
el descubrimiento de nuevas formas se esperan en el futuro.
Introduction
The hierarchical rank of the South American characoids here recognized as
comprising the family Anostomidae has fluctuated like most of the suprageneric
groupings among these fishes. I follow Greenwood et al. (1966) and Lindberg (1974)
in elevating the subfamily Anostominae of Myers (1950) and Géry (1961) to family
status. The closest relatives of this assemblage may lie among the chilodontid fishes
(Roberts, 1969:424), the two families sharing unique characters (for characoids) such
as the posteriorly replaced and cusped pharyngeal teeth. Gery (1961) did not mention
chilodontids as possible relatives of his Anostominae, but his dendrogram does
include curimatids, prochilodontids, erythrinids, lebiasinids and hemiodontids.
Cockerell (1914) placed Anostomus in his Hemiodinae (while retaining, for some
reason, the Anostomatinae for Leporinus), and stated that the scale structure of the
two genera was very similar.
Although this paper is not concerned with the relationships of the entire family
Anostomidae, I propose a new concept for the subfamily Anostominae (here
conceived as encompassing the genera Anostomus, Pseudanos, Gnathodolus, Sartor
and Synaptolaemus) on the basis of its monophyly (see the diagnosis of the
subfamily, p. 4, and discussion, p. 48).
Other genera I recognize in the family Anostomidae (but here exclude from the
Anostominae) are Abramites, Anostomoides, Laemolyta, Leporellus, Leporinus,
Rhytiodus and Schizodon, following Myers (1950) and Géry (1961, 1972/73). This
number will probably be increased when further specimens make it possible to
describe formally an anostomid with more than 65 lateral line scales from the vicinity
of Manaus figured and described (but not named) by Géry (1972/73), and another
form from the Essequibo River which has an incomplete lateral line (and is
represented by three small specimens in the collections of the National Museum of
Canada).
After this paper had been accepted for publication, I received a copy of Géry’s
(1977) ‘‘Characoids of the world’’. In this work, Géry recognizes the family
Anostomidae, and includes all the genera accepted here. However, we differ
significantly in subsequent subdivision. Géry (op. cit.) recognizes a subfamily for
Leporellus (Leporellinae), and includes all other genera in his subfamily
Anostominae. He gives two characters to justify this decision, but both would appear
to be autapomorphies of Leporellus (nostrils close together, caudal fin scaly). Perhaps
more importantly, Géry includes Laemolyta as a subgenus of Anostomus, while
continuing to recognize the monotypic genera (Gnathodolus, Sartor and Synap-
tolaemus) as distinct. The evidence presented by Géry appears to be based on
suggestions that Laemolyta shows a more or less intermediate condition in mouth
position, nature of the teeth, and head-standing proclivities between Anostomus and
the more generalized anostomids. While this may be true, it does not justify the
inclusion of Laemolyta in Anostomus in terms of phylogenetic reasoning. Thus it is
not surprising that Géry’s conclusion is not supported by the results of this
investigation—indeed, Anostomus (Anostomus) as conceived by Géry is itself a
paraphyletic group. It may be, however, that Laemolyta represents the sister group of
the Anostominae as here conceived (implying that the non-anostomine anostomids
are not monophyletic), but this possibility must await further investigation.
Géry’s (1977) book is of considerable interest for the colour photographs of six
species of anostomines, most of them by Harald Schultz. Among these are
Synaptolaemus, Sartor and, probably, the new species of Anostomus described in this
paper. Schultz collected the specimens of the latter from Brazil’s Xingu River—the
caption of the plate is ‘‘Anostomus (Anostomus) plicatus’’ a species which is
restricted to the Essequibo River System of Guyana. I have not seen any specimens of
the true A. plicatus that have been collected by Schultz, and I suspect the plate is of
the new species from the Xingu.
The subfamily is more or less restricted to the Amazon basin (exclusive of the Rio
Negro, although a few small specimens, usually of P. gracilis and P. trimaculatus,
have been collected in the Rio Negro near Manaus), the Orinoco, and the eastward
flowing rivers of the Guyanas and Surinam. Such information as exists on the habitat
of these fishes indicates a fairly broad spectrum ranging from small streams to
relatively large rivers. The genera Anostomus and Pseudanos appear to be
predominantly herbivorous, although occasionally taking insects and their larvae in
large numbers (Winterbottom, 1974a). Weitzman (pers. comm.) has observed about
20 specimens of A. anostomus picking mucus off an Australian lungfish in an
aquarium. An aquarium specimen of Gnathodolus has been observed to remove
scales from its tank mates (G. Howes, pers. comm.), a possible function of the
greatly enlarged symphyseal lower jaw teeth of this species.
One of the difficulties commonly encountered by ichthyologists studying South
American fishes is the paucity of comprehensive collections from almost the entire
area. (A notable exception is the extensive material collected by Nijssen and
Boeseman in Surinam.) As a result, it is often all but impossible to discover whether
two apparently different forms are linked by continuous but as yet unsampled
populations or represent different species. The problem is particularly apparent
among anostomines in the P. trimaculatus species complex.
A characteristic of all anostomines so far observed alive is their proclivity to adopt
a near vertical, head down position in the water. Quite what, if any, the relationship
of this position has to the upturned mouth of these fishes has not, to my knowledge,
been investigated. Since Knoppel’s (1972) work indicates that most of the species of
this subfamily are herbivores/detritovores, I find it difficult to envisage a causal
relationship between mouth position and head standing.
Materials and Methods
Specimens from many museums (see Appendix I and Acknowledgements) were
measured with dial calipers to the nearest tenth of a millimeter. The method of
counting and measurement follows Winterbottom (1974a). See Figure 1. A total of 36
characters was taken from each specimen. Two computer programs were used to
process the data, one to transform the morphometric data to percentages, and print out
the mean, range, standard deviation and standard error. This program also drew up
Hubbs-Hubbs diagrams and performed an analysis of variance. The second program
drew the graphs and the regression line. The coefficient of determination (R*) was
3
calculated by the following formula (taken from the Hewlett-Packard HP-25
Applications Programs, 1975). The assumption is made that the relationship between
variables is linear (which is not always true).
The synonymies given in the systematic section of this paper are selective, ignoring
for the most part the scattered and often inaccurate aquarium literature.
Skull proportions taken from cleared and stained material are measured as follows:
length—anterior tip of ethmoid to basioccipital condyle; width—between hyoman-
dibular fossae where sutures of prootic, pterotic and sphenotic meet.
Systematic Section
Subfamily Anostominae (new concept)
Diagnosis
South American characoids with a supra-terminal (i.e. dorsally opening) mouth, four
teeth in each half of upper jaw and one to four teeth in each half of lower jaw. Apart
from abnormal individuals, dorsal fin always iii 10 or iv 9, anal iii 8 or iv 8, dorsal
transverse scales 342-6, ventral transverse 3-5, 12 or 16 circumpeduncular scales,
37-45 lateral line scales and 35-42 vertebrae (excluding ural centrum). Gill
membranes usually fused to isthmus. Metapterygoid/quadrate fenestra very much
reduced, or absent, dorsal portion of metapterygoid either sloping medially or
horizontal. Median ethmoid always longer than wide, no rhinosphenoid, paras-
phenoid with a vertical flange or lamina of bone. Last ray of dorsal and anal fin split
to base, adipose fin present. Dorsal and pelvic fins inserted at about middle of body,
head length 22-33 per cent SL. Figure 2 shows Hubbs-Hubbs diagrams for
lateral-line scales of anostomines. Table 1 presents the mean and ranges of the
Anostominae for selected body proportions, lateral-line scales and vertebrae.
Artificial Key to the Genera and Species of the Anostominae
1.
Symphyseal (medial) teeth of lower jaw essentially same size as
those next (lateral) to them; lower jaw (bone without teeth) as
long as wide; lips without dermal papillae (may be corrugated) ................ 4
Symphyseal (medial) teeth of lower jaw enlarged; lower jaw
(bone without teeth) longer than wide; lips with distinct dermal
rege y oy oes CEM sed a eo ae RS a eer oe ee ee ee ee ee ee ee Z
. Circumpeduncular scales 16, head depth 80-90 per cent of head
length; a single tooth in each half of lower jaw (Ori-
noco/Casiquiare bifurcation) (x: .Wi Gaat co i ae Gnathodolus bidens
Circumpeduncular scales 12, head depth less than 80 per cent of
headvlenethySitor4tecthvintlower jaw) 5 28. Lede a RAM ealeaigees aGalae sce 2
. Lower jaw about five times as long as wide, inclined
posterodorsally when mouth fully closed; three teeth in lower jaw,
symphyseal pair being five times as high as wide and projecting
above upper jaw when mouth closed (upper Xingu) ........... Sartor respectus
Lower jaw about twice as long as wide, vertical when mouth fully
closed; four teeth in lower jaw, symphyseal teeth about twice as
high as wide (Orinoco system and upper Xingu) .... Synaptolaemus cingulatus
. Colour pattern of more than one dark longitudinal stripe greater
than-one Scaleswide oma pale, DACKOTOMMG oc cesta: ceticieiejenitinieys Sopdoreerbeteeines + 5
Colour pattern without longitudinal stripes greater than one scale
wide; with two to four dark blotches or spots along lateral line
(except in some individuals or P. gracilis where a single stripe
centred on lateral line may be present, and no dark blotches
BR SANG) Mere tear. nme ee eA ELS, CML, Seo MONA get tec mete tdi eee bed ween paaEe qi
. Three branchiostegal rays, a median light longitudinal stripe
along predorsal region, rows of light spots on anterior dorsum
(south-eastern Amazon tributaries, Orinoco system and drainages
Sout Of this-tovSurimatn) sais. te. «aged eds 1 fes. cameo eee. 186 Anostomus ternetzi
Four branchiostegal rays (first ray may be much reduced); a
median dark longitudinal stripe along predorsal region, no spots ................ 6
. Greatest body depth 27.5-29.5 (x = 27.9) per cent SL; depth of
head 78-85 (x = 81.4) per cent head length; 12 caudal vertebrae
(including ural centrum and vertebra of haemal spine which lies
just anterior to first anal pterygiophore) (French Guiana) .. Anostomus brevior
Greatest body depth 16.0-28.5 (x = 22.6) per cent SL; depth of
head 49.5-80.0 (x = 66.2) per cent head length; usually 11
caudal vertebrae (12-13 rarely) (Amazon and Orinoco systems
and drainages south of the Orinoco to Surinam) ......... Anostomus anostomus
ae
. Four branchiostegal rays; symphyseal teeth of lower jaw truncate
in specimens of 60 mm SL and larger; distance from snout to
pelvic fin origin greater than distance from dorsal fin origin to
Caudal: fin OPIS yc io enh ouvert Sathyae beer cha ace ee eee 8
Three branchiostegal rays; symphyseal teeth bicuspid (occasion-
ally truncate from wear in large specimens >80 mm SL); distance
from snout to pelvic origin equal to or less than distance from
dorsal finorigin to,.caudal fin ofigin, 4... ¢4..4. Jb4..uq lence webs pomesree renee: 10
. Snout length 40 per cent of head length; vertical pigmented areas
absent below lateral line (Upper Xingu) ....... Anostomus intermedius sp. nov.
Snout length 43-44 per cent of head length; vertical pigmented
areas “present: below lateral tine*2it. eee. oon. peek see eave, deems 9
. Lateral line scales 40-42; caudal peduncle length about equal to
its depth; vertical pigmented areas two scales wide (Nickerie,
Surinam’), Merce se Bale oh Oe eee, Oe Serna eae eee Anostomus spiloclistron
Lateral line scales 38-39; caudal peduncle length less than its
depth; vertical pigmented areas one scale wide (Essequibo,
GUY ania) SR ORe Oh He See eee UE E LN ret te ser tn mee Anostomus plicatus
. Colour pattern in alcohol consisting of longitudinal lines of dark
spots in centres of scales with no vertical pigmented areas across
dorsal midline; angle between posterior three primay radii on
scales below dorsal fin 40—90° (Orinoco, Negro and Mato Grosso)
is trace va n's gorge the ween naes a tadarrs: oni ame ae eats Actee (Sek Pseudanos gracilis
Colour pattern in alcohol always of vertical pigmented areas
across dorsum, and two to four large blotches or spots (covering
more than one scale) centred on lateral line; angle between
posterior three primary radii on scales below dorsal fin 110—180° ................ 11
Colour pattern in alcohol with dark spots in centres of scales
(Orinoco; Guyana) ie ae ee eee ee Pseudanos irinae sp. nov.
Colour pattern in alcohol with centres of scales light (Amazon
South of the INeeroye: Aah: OSes ee eens cee Pseudanos trimaculatus
Clave Artificial para los Géneros y Especies de los Anostominae
I
Dientes simfiseos (medios) de la mandibula inferior parcialmente
iguales a los que los rodean (laterales); mandibula inferior (hueso
sin dientes) igual de largo que de ancho; labios sin papilas
demmicasd(puede Sek annusadO) ..Aaso2 327) eis atahsl 528! ocd lise checkesec. ses reece ses =
Dientes simfiseos (medios) de la mandibula inferior alargados;
mandibula inferior (hueso sin dientes) mas larga que ancha; labios
CONGO AM MASE GSTMMUCAS TNUY, (CLARAS ei Sac ay bi ova ie opaishetetra rs a0 opeustebor joint wikia Bu2 ahs Shaper eabicbeyno = « Z
. Escamas circumpedunculares 16, altura de la cabeza 80 a 90 por
ciento del largo de si misma; un solo diente en cada lado de la
mandibula inferior (bifurcaci6n Orinoco/Casiquiare) ....... Gnathodolus bidens
Escamas circumpedunculares 12, altura de la cabeza menos del 80
por ciento del largo de si; tres a cuatro dientes en la mandibula
META Tys ee tere at aI ee Le aIe ore nual, Seu LREM ee aR E On eee Pena S 3
. Mandibula inferior cinco veces mas larga que ancha, inclinada
posterodorsalmente cuando la boca esta completamente cerrada;
tres dientes en la mandibula inferior; el par simfiseo es cinco
veces mas alto que ancho y se proyectan sobre la mandibula
Superior cuando la boca esta cerrada (Xingu superior) ......... Sartor respectus
Mandibula superior dos veces mas larga que ancha, vertical
cuando la boca esta cerrada; cuatro dientes en la mandibula
inferior, dientes simfiseos (medios) dos veces mas altos que
anchos (sistema Orinoco y superior Xingu) .......... Synoptolaemus cingulatus
. Colorido con mas de una banda longitudinal y cada banda mas
anicha que une-escalma (Cl Wil TONGO PalidO) ©... 2. cccec st ee cet ee or hen twine nen nals BS)
Colorido en bandas longitudinales de no mas de una escama de
ancho; con dos a cuatro manchas oscuras, o bién manchas a lo
largo de la linea lateral (excepto en algunos individuos 6 en P.
gracilis donde una sola banda centrada en la linea lateral puede
Estar presente, -y NO Manchas, OCUFTER) 6. isc sn, yao cae oriaaneediem seme ibenecamen es. i
. Tres radios branquiostegos; una banda clara a lo largo de la region
predorsal media; una hilera de manchas claras en la parte anterior
del lomo (tributarios del sudeste del Amazonas, sistema del
Orinoco y afluentes del Sur hasta Surinam) .................. Anostomus ternetzi
Cuatro radios branquiostegos (primer radio puede estar reducido);
una banda longitudinal oscura a lo largo de la region predorsal; no
Mane hasSypheSeMieS mint. Ames! heat AMES 5 UENO tt So ha eet ek Ca 6
. Mayor altura del cuerpo 27.5-29.5 (x = 27.9) por ciento SL;
altura de la cabeza 78-85 (x = 81.4) por ciento del largo de la
cabeza; 12 vertebras caudales (incluyendo el centro ural y
vertebras de la espina hemal que se encuentran un poco mas
adelante que el primer pterigioforo) (Guyana francesa) ..... Anostomus brevior
10.
Pls
Mayor altura del cuerpo 16.0—28.5 (x = 22.6) por ciento SL;
altura de la cabeza 49.5-80 (x = 66.2) por ciento del largo de la
cabeza; generalmente 11 vertebras caudales (raramente 12-13)
(sistema del Amazona y Orinoco y los afluentes del Orinoco a
Sutihalil).) 54a. sche ck ye wo eee se ease een eee eee ee Anostomus anostomus.
Cuatro radios branquiostegos; dientes simfiseos de la mandibula
inferior se hayan truncados en ejemplares de 60 mm SL o mas;
distancia del hocico al origen de la aleta pélvica, mayor que la
distancia desde el origen de la aleta dorsal al origen de la aleta
Caudal... iting pcnaturde, wiht. gies ataea dint Scatinn aaptepiten oles sacle ol tame. 5 le oem a 8
Tres radios branquiostegos; dientes simfiseos bicuspidos
(ocasionalmente truncados por el uso en especimenes >80 mm
SL); distancia desde el hocico el origen de la aleta pélvica igual o
menor que la distancia desde el origen de la aleta dorsal al origen
detavaletabcauid alin, eee S40. ee Seah yoni Be MA. be Re OS eer eee 10
. Largo del hocico 40 por ciento del largo de la cabeza; zonas
vérticales pigmentadas ausentes bajo la linea lateral (Xingu
SUDEMIOG) | oe ght asst aN aa ocomubaroniys epic Anostomus intermedius sp. nov.
Largo del hocico 43-44 por ciento del largo de la cabeza; zonas
vérticales pigmentadas presentes bajo la linea lateral ......................0..0005 9
. 40-42 escamas en la linea lateral; largo del pedunculo caudal, casi
igual a su altura zonas verticales pigmentadas dos escamas de
acho“ (NICKeries SUPMAM) 22 ).ce cesses ace ne os tence. Anostomus spiloclistron
Escamas en la linea lateral 38-39; largo del pedunculo caudal
menos que su altura; zonas vérticales pigmentadas de una escama
de-ancho (Essequibo; (Guyana) pi.c.2. ats oatuiqa teason ee wae Anostomus plicatus
Colorido en alcohol muestra bandas longitudinales con lunares
oscuros en el centro de las escamas; sin areas veérticales
pigmentadas a través de la linea media dorsal; angulo entre los
tres radios primarios posteriores de las escamas bajo la aleta
dorsal’40=90> (Orinoco, Negro: y;Matto (Grose) 25622-62422 ee eee eee 11
Colorido en alcohol siempre con areas vérticales pigmentadas a
través del lomo, y dos a cuatro manchas grandes o pequefnas
(cubriendo mas de una escama) centradass en la linea lateral;
angulo entre los tres radios primarios posteriores de las escamas
bajo fa-aletasdorsal sh1O— L805) i. tah. Scant uli aperacery Sees Sere ae ae 11
Colorido en alcohol con manchas negras en el centro de las
escamas (Orinoco,,Guyana) ie ee. ...65- 8: A tos Pseudanos irinae sp. nov.
Colorido en alcohol con centros de las escamas claros (Amazona,
sur’del NG GrO) 22. cn cathaa: ea: s cab aderat ate «aera oc Pseudanos trimaculatus
Anostomus (Gronow) Scopoli 1777
Anostomus Gronow 1763:122 (description and figure, no species mentioned, work
not accepted by ICZN).
Anostomus Scopoli 1777:451 (not seen, compiled from Myers 1950:191. No species
mentioned, but based on Gronow and therefore type species, by monotypy, must be
that illustrated by Gronow 1756 which is Salmo anostomus Linnaeus).
Anostoma Rafinesque 1815 (not seen, compiled from Myers 1950:191. Emendation
of Anostomus).
Mormyrhynchus Swainson 1839:186, 291 (type by monotypy. M. gronoveii
Swainson, based on Gronow 1763, pl. 7, fig. 2 which is reproduced from Gronow
1756, and is thus Salmo anostomus Linnaeus).
Histiodromus Gistel 1848 (not seen, compiled from Myers 1950:191. Type by
monotypy Salmo anostomus).
Pithecocharax Fowler 1906:319 (type by original designation, Salmo anostomus
Linnaeus).
Diagnosis
Anostomus may be distinguished from Sartor and Synaptolaemus by presence of 16
circumpeduncular scales (vs 12) and from Gnathodolus by possession of 4 lower jaw
teeth (vs 1). Species of Anostomus may be further distinguished from these genera in
having a bony lower jaw (without teeth) as long as wide (vs longer than wide) and by
absence of conical or rounded dermal papillae on lower jaw (vs papillae present).
Species of Anostomus may be distinguished from Pseudanos by presence of four
branchiostegal rays (except A. ternetzi, which, like Pseudanos, has three), in usually
having 40 or fewer lateral line scales and 38 or fewer vertebrae (vs 41 or more scales
and 39 or more vertebrae). Numerous osteological differences are mentioned in the
discussion section of this paper.
Anostomus anostomus (Linnaeus, 1758)
Fig. 3
Salmo anostomus Linnaeus 1758:312 (original description based on Gronow 1756,
type locality: ‘‘Indiis’’).
Anostomus Scopoli 1777 (no species mentioned, but based on Salmo anostomus
Linnaeus).
Anostomus anostomus — Meuschen 1775:37 (not seen, compiled from Géry 1960);
Myers 1950:192 (partim); Géry 1960 (subspecies); Myers and de Carvalho 1959
(feeding habits); Knoppel 1972 (diet).
Mormyrhynchus gronoveii — Swainson 1839:291.
Histiodromus anostomus — Gistel 1848.
Leporinus anostomus — Valenciennes, in Cuvier and Valenciennes 1849.
Anostomus salmoneus — Gronow 1854:153 (Ed. Gray).
Pithecocharax anostomus — Fowler 1906:319.
Diagnosis
A. anostomus may be distinguished from all other anostomines (except A. brevior and
A. ternetzi) by its colour pattern of dark longitudinal stripes on a light background. It
is differentiated from A. brevior in having a shorter caudal peduncle (4 per cent of the
212 speciments examined overlap with lower percentage limit of A. brevior) and a
less deep body and head (1.4 per cent and 0.5 per cent overlap respectively;
specimens which overlapped only did so in one of three characters mentioned). See
Table 1. These differences are also apparent when using other morphometric
parameters (Fig. 4, peduncle depth vs peduncle length; Fig. 5, body depth vs head
length; Fig. 6, head depth vs head length). A. ternetzi also tends to have a longer
caudal peduncle (x 13.9 per cent SL — a single specimen with 10.1 per cent, all
others above 13 per cent), and may be further separated in possessing three
branchiostegal rays, a median light predorsal stripe and light spots on the dorsum (vs
four branchiostegal rays, a dark median predorsal stripe and no light spots on the
dorsum in A. anostomus).
Description
A fusiform, striped, compressed Anostomus (size range of specimens examined
36-107 mm SL), with a moderately elongated snout. The following measurements
are expressed as percentages, and these and the meristics consist of a mean, the range
in parentheses, the standard deviation and the standard error respectively.
As percentage of standard length: lower jaw to anal-fin ongin 83.8 (78.3-87.7),
0.016, 0.001; lower jaw to adipose-fin origin 88.3 (82.0-91.3), 0.013, 0.001; lower
jaw to dorsal-fin origin 49.4 (46.3-52.1), 0.010, 0.001; lower jaw to pelvic-fin origin
52.2 (48.7-56.0), 0.013, 0.001; dorsal-fin origin to caudal-fin origin 52.8
(46.8-56.5), 0.013, 0.001; dorsal-fin origin to adipose-fin origin 40.0 (34.4-43.8),
0.013, 0.001; caudal peduncle length 11.6 (9.3-15.0), 0.010, 0.001; caudal peduncle
depth 10.7 (9.0-12.7), 0.010, 0.001; head length 26.5, (23.4-31.9), 0.012, 0.001;
body depth 22.6 (16.1—28.4), 0.026, 0.002; body width 12.3 (10.5-13.9), 0.006,
0.001.
As percentage of head length: preopercle length 73.8 (68.6—79.0), 0.017, 0.001;
snout length 41.0 (36.1-46.1), 0.021, 0.001; head depth 66.2 (49.7-79.8), 0.070,
0.005; preopercle depth 54.0 (45.2-61.6), 0.033, 0.002; snout depth 34.2
(29.7-39.0), 0.016, 0.001; eye diameter 23.3 (18.9-28.0), 0.016, 0.001; bony
interorbital 32.8 (29.6—36.3), 0.012, 0.001.
Lateral-line scales 39.3 (38-43, usually 39-40) 0.637, 0.044; dorsal transverse 4.5
(4-5), 0.151, 0.010; ventral transverse 3.8 (3.5-4.5), 0.306, 0.021; predorsal 11.7
(9-13), 0.807, 0.055; dorsal to adipose 12.9 (11-14), 0.626, 0.055; adipose to
caudal 6.8 (6-8), 0.563, 0.049; isthmus to pelvis 17.2 (15-18), 0.735, 0.064; pelvis
to anus 11.5 (10-13), 0.593, 0.050; anal to caudal 6.1 (5-8), 0.545, 0.048,
circumpeduncular 16.
Scales (from scale row immediately above lateral line and in line with dorsal fin
origin) divided roughly into quarters by four primary radii approximately at right
angles (Fig. 7A) in specimens up to about 55 mm SL. Angle between the dorsal and
ventral radii is thus about 180°. In larger specimens number of radii generally
10
increases (nine in a 107 mm SL specimen) and a few reticulations may appear around
focus. Lateral-line scales usually with four posterior radii, one passing along the
lateral-line tubule to posterior edge of scale (Fig. 7A).
Dorsal fin usually iii 10 (occasionally iv 9 or iii 9), caudal fin normally of 10 dorsal
and 9 ventral principal rays (occasional variants with 9 or 11 upper, or 8 lower rays);
anal usually iii 8 (rarely 111 7), pelvic i 8 (seldom i 7, and then usually on one side
only); pectoral i 12 —i 16 (x i 14.2, SD = 0.690, SE = 0.047). Number of olfactory
lamellae increasing body size from 18 in 36.1-42.0 mm SL specimens to 38 in a
specimen 90.6 mm SL; vertebrae usually 36 + ural centrum (with 11 caudal
including ural centrum) range 35-39, x = 36.2, SD = 0.787, SE = 0.186 (n=20).
First pterygiophore of dorsal fin inserts between neural spines of eleventh and twelfth
vertebrae. Four branchiostegal rays.
Teeth orange-brown, four in each half of both upper and lower jaws. Cusps fairly
consistent, in upper jaw usually (from symphysis out posterolaterally) two cusps on
first and second teeth, three on third and four on lateralmost tooth, in lower jaw, three
cusps on first three teeth and lateralmost tooth with four cusps. Commonest variation
found was wearing away of cusps of inner two upper jaw teeth and innermost lower
jaw tooth, this virtually confined to a few individuals over about 85 mm SL. Upper
jaw teeth point straight forward; those in lower jaw recurved, pointing posteriorly and
somewhat dorsally, and lying outside upper jaw teeth when the mouth is fully closed.
Colour pattern in alcohol consists of a light background with black longitudinal
stripes:
1) Median dorsal stripe begins between eyes and ends at last dorsal fin ray;
2) Dorsolateral stripe begins at base of upper jaw lips where it is more or less
continuous with dorsolateral stripe of opposite side. Stripes join again on dorsal
midline somewhat anterior to adipose fin, and continue posteriorly as a single stripe
to caudal-fin rays. Stripe about one scale wide, and follows course of third scale row
above lateral line;
3) Midlateral stripe begins at front of lower jaw and passes posteriorly through eye,
across opercle, and along lateral-line scale row to base of caudal peduncle. It is
usually somewhat irregular, and may extend half a scale row above and below
lateral-line series;
4) Ventrolateral stripe begins on preopercle anterior to eye, crosses subopercle and
base of pectoral fin, and continues posteriorly along third scale row below lateral line
to meet stripe from opposite side at origin of anal fin. They then continue posteriorly
as a single stripe to caudal-fin origin;
5) Midventral stripe begins at lower jaw and passes posteriorly across branchios-
tegal membrane to pelvic fins, and from there on to anus. In some specimens the
region between isthmus and pelvic fins may possess a thin longitudinal light stripe in
midline. Adipose fin black in very small specimens, becoming hvaline distally with a
black spot at base in specimens about 60 mm SL, black pigment disappearing with
increasing body size. Other fins hyaline.
In life, background is ivory-yellow, stripes being dark-brown to black. Dorsal,
caudal, anal and sometimes pelvic fins are suffused with red, which is most intense
on caudal and posterior rays of dorsal and anal fins. (Above description from
aquarium specimens, locality unknown.)
11
Distribution
A. anostomus appears to have a wide distribution (Fig. 8), including the middle
(Steindachner, 1882) and upper (Géry, 1960, and present study) Amazon, the
Orinoco, and many of the rivers of Guyana and Surinam. Specimens from Guyana
and Surinam are particularly abundant in museum collections, but this is an artifact of
collecting effort. Géry (1960) recognized two subspecies, A. anostomus anostomus
from the Orinoco/Guyana/Surinam region, and A. a. longus from the upper Amazon.
Although the Rio Negro may well provide a geographic barrier (in terms of black
water/white water preferences) between these populations, Géry distinguished them
solely on the basis of body depth. My material from the Amazon (three paratypes of
the subspecies) is insufficient to critically examine the reported difference, and I am
somewhat sceptical of the usefulness of such a distinction. Be that as it may, there
seems little doubt that the ranges of the two populations (based on available
information) at one time overlapped, implying a more extensive distribution for this
species in the past. Judging from the Surinam collections, A. anostomus seems to
prefer sandy or muddy substrates in slowly flowing creeks of up to 1 m in depth.
Knoppel (1972) reports that four specimens of the Amazonian population contained
plant remains, algae, fungi, chitin remains, copepod crustacea and sand in their
stomachs.
The species has also been recorded in the literature from Colombia (Florencia on
the Orteguaza River which drains via the Caqueta and Japura Rivers into the Amazon,
(Fowler, 1943, 1945)), and from the Rio Jutai at its junction with the Amazon
(Steindachner, 1882).
Variation
Several factors can effect the amount of variation found in fishes. Amongst these, two
species of Anostomus have been shown to exhibit growth inflections (Winterbottom,
1974a). These occurred at approximately 75 mm SL, which may indicate the onset of
sexual maturity. A. anostomus exhibits sexual dimorphism in the depth of the caudal
peduncle. When plotted against standard length, the regression lines for males and
that for females are well separated (Fig. 9). In a sample of 25 specimens (ZMA
106.528, Surinam) there were 10 males, 11 females and 4 immature. The immature
specimens fall close to the line of regression for the females (R?= 0.95) and are quite
well separated from that for the males (where R? = 0.98). This may indicate a linear
growth in immature and female fish, but a growth inflection in the males. Onset of
sexual maturity appears to occur between 60 and 65 mm SL (somewhat less than that
postulated for A. spiloclistron and A. plicatus (75-80 mm SL) by Winterbottom (op.
Cit.)
Anostomus brevior Géry, 1960
Fig. 10
Anostomus brevior Géry 1960:499 (original description, type locality: Camopi River,
Oyapok river system, French Guiana); Knoppel, 1972 (gut contents).
12
Diagnosis
A. brevior is distinguishable from all other anostomines (except A. ternetzi and
A. anostomus) by its colour pattern of dark longitudinal stripes on a light background.
It may be distinguished from A. anostomus by its longer caudal peduncle and deeper
body and head (Table 1; see also Figs. 4 to 6). In addition to the last two characters, it
differs from A. ternetzi in having four branchiostegal rays (vs three) and a dark stripe
along middle predorsum (vs a light stripe).
Description
A fusiform, somewhat deep bodied Anostomus (size range examined 69.1—86.5 mm
SL) with a maximum recorded length of 91 mm SL (Géry, 1960). The following
measurements are expressed as percentages, and these and the meristics consist of a
mean with the range in parentheses.
As percentage of standard length: lower jaw to anal-fin origin 81.1 (79.2—83.3);
lower jaw to adipose-fin origin 86.9 (86.3—88.2); lower jaw to dorsal-fin origin 50.0
(47.5—-51.9); lower jaw to pelvic-fin origin 51.1 (49.7-52.4); dorsal-fin origin to
caudal-fin origin 53.4 (51.8-54.4); dorsal-fin origin to adipose-fin origin 39.9
(37.4-42.4); caudal peduncle length 13.2 (12.6—-14.1); caudal pecuncle depth 11.1
(10.1—11.8); head length 25.5 (25.1—26.3); body depth 27.9 (27.4—29.5); body width
13.3 (12.7-13.8).
As percentage of head length: preopercle length 74.8 (74.6—75.3); snout length
39.8 (38.3-41.1); head depth 81.4 (78.8-84.8); preopercle depth 60.7 (58.1-63.6);
snout depth 36.2 (33.3-38.1); eye diameter 21.4 (19.8—22.6); bony interorbital 34.5
(33.6-35.6).
Lateral-line scales 38.6 (38-39); dorsal transverse 5.0 (5); ventral transverse 4.0
(4); predorsal 11.6 (11-12); dorsal to adipose 13.0 (12-14); adipose to caudal 7.2
(7-8); isthmus to pelvis 16.8 (16-17); pelvis to anus 10.6 (10-11); anal to caudal 6.6
(6-7); circumpeduncular 16. Scale form as for A. anostomus.
Dorsal fin 111 10 (once iv 9), caudal fin of 10 dorsal and 9 ventral principal rays,
anal 111 8, pelvic i 8, pecioral 1 14 (once i 13). Number of olfactory lamellae
increasing with body size, from 28 ina 73.2 mm SL specimen to 32 in a 81.5 mm SL
specimen. Vertebrae usually 36 + ural centrum (once 37), with 12 (once 13) caudal
vertebrae including ural centrum (x = 36.2). First pterygiophore of dorsal fin inserts
between neural spines of eleventh and twelfth vertebrae (once twelfth and thirteenth).
Four branchiostegal rays. Teeth as for A. anostomus, as is colour pattern with a few
minor differences. Dorsolateral stripes join at adipose fin origin (slightly more
posteriorly than in A. anostomus), ventrolateral stripe is separated by a light stripe
one scale row wide in ventral midline between isthmus and pelvis (as in some
specimens of A. anostomus). Live colours as for A. anostomus, including red
suffusion of fins (Géry, 1960).
Distribution
So far reported only from the Oyapok River system at its junction with the Camponi
River and from the middle and upper Mana River at Cariacou and Dégrad Sanson
respectively in French Guiana (Fig. 8). Knoppel (1972) reported the food of three
specimens from the Mana River to consist primarily of detritus and diatomaceous
algae.
Anostomus intermedius sp. nov.
Fig. 11
A. plicatus (non Eigenmann) — Géry, 1972-73 (upper Xingu, D’Arcy Thompson
deformation coordinates); Knoppel, 1972 (upper Xingu, stomach contents —
recorded as A. plicatus (?)).
Diagnosis
A. intermedius may be separated from the monotypic anostomine genera
(Gnathodolus, Sartor and Synaptolaemus) by a combination of 16 circumpeduncular
scales and four teeth in each half of the lower jaw. It may be separated from the
striped Anostomus group (A. anostomus, A. brevior and A. ternetzi) by the
possession of spots or blotches along the lateral line and dark bars across the dorsum.
It may be differentiated from the species of Pseudanos by the truncate nature of
symphyseal lower jaw teeth (vs bicuspid) in individuals larger than 60 mm SL, four
branchiostegal rays (vs three), a greater snout to pelvic fin origin (x = 57 per cent SL
vs 51-52 per cent), shorter dorsal-fin origin to caudal-fin origin (51 per cent SL vs
54-55 per cent), a narrower interorbital (x = 33 per cent HL vs 35-38 per cent),
fewer lateral-line scales (x = 39 vs 42-45) and vertebrae (x = 36 vs 39-41). It differs
from A. spiloclistron in the same way that A. plicatus does: a somewhat longer
caudal peduncle (x = 13 per cent SL vs 12 per cent), two less lateral line scales
(x=39 vs 41), and two less vertebrae (x = 36 vs 38). It differs from both these
species in shorter snout length (x = 40 per cent of head length vs 43-44 per cent;
Figs. 12 and 13), in lacking any vertical pigmented areas below lateral line, and in
fewer teeth on ceratobranchial 5 and fifth pharyngobranchial tooth plate.
Description
A. intermedius 1s a moderately elongate fusiform fish (size range of specimens
examined 49-92 mm SL). The following measurements are expressed as _ per-
centages, and these and the meristics consist of a mean, the range in parentheses, the
standard deviation and the standard error respectively.
As percentage of standard length: lower jaw to anal-fin origin 81.5 (80.2—82.5),
0.007, 0.002; lower jaw to adipose-fin origin 86.3 (85.1—87.8), 0.008, 0.002; lower
jaw to dorsal-fin origin 52.8 (50.3—54.6), 0.011, 0.003; lower jaw to pelvic-fin origin
56.7 (55.0—-58.7), 0.008, 0.002; dorsal-fin origin to caudal-fin origin 50.7
(49.2-52.4), 0.009, 0.002; dorsal-fin origin to adipose-fin origin 35.6 (33.9-37.3),
0.009, 0.002; caudal peduncle length 13.1 (12.2-14.3), 0.006, 0.002; caudal
peduncle depth 11.9 (11.6-12.3), 0.002, 0.001; head length 30.1 (27.8-31.9),
0.013, 0.003; body depth 27.2 (24.7-29.6), 0.012, 0.003; body width 14.3
(12.9-16.2), 0.009, 0.002.
As percentage of head length: preopercle length 72.7 (70.9-76.1), 0.013, 0.003;
snout length 40.1 (38.9-42.1), 0.008, 0.002; head depth 74.8 (70.9-83.9), 0.040,
0.010; preopercle depth 60.8 (57.0-66.2), 0.025, 0.006; snout depth 36.0
(33.5-39.4), 0.020, 0.005; eye diameter 22.2 (20.5-24.0), 0.015, 0.004; bony
interorbital 32.9 (30.4—35.0), 0.015, 0.004.
Lateral-line scales 38.9 (38-40), 0.515, 0.125; dorsal transverse 6, ventral
transverse 4.5, predorsal 16.1 (15-17), 0.858, 0.208; dorsal to adipose 11.4 (10-13),
14
0.870, 0.211; adipose to caudal 6.8 (6-8), 0.636, 0.154; isthmus to pelvis 17.5
(17-21), 1.007, 0.244; pelvis to anus 9.4 (9-11), 0.618, 0.150; anal to caudal 6.3
(5-7), 0.686, 0.166; circumpeduncular 16. Scales from row above lateral line and
from lateral line (below dorsal origin) as for A. plicatus (Fig. 7D).
Dorsal fin iii 10, caudal fin with 10 upper and 9 lower principal rays, anal fin iii 8,
pelvic fins each i 8, pectoral fin i 14-1 16. Number of olfactory lamellae increasing
with body size, from 22 in a 50 mm SL specimen to 36 in a 92 mm SL individual.
Vertebrae 35.9 (35-37), plus ural centrum, with 11-12 caudal (including ural
centrum) and first pterygiophore of dorsal fin inserting between neural spines of
eleventh-twelfth or twelfth—thirteenth vertebrae. Four branchiostegal rays.
Teeth orange-brown, four in each half of each jaw. In upper jaw, symphyseal tooth
tricuspid, next tooth tricuspid in individuals less than 55 mm SL, biscuspid in
specimens larger than this, next tooth tricuspid (bicuspid in largest specimen),
lateralmost tooth tricuspid. In lower jaw of specimens smaller than 55 mm SL,
symphyseal and next tooth bicuspid, next and lateralmost teeth tricuspid. In larger
specimens inner two teeth may be bicuspid, or, more usually, truncate.
Colour pattern of subadults in alcohol consisting of bars, about one scale row wide,
over dorsum with spots and elongate blotches along the lateral line. The six to nine
bars (which seldom reach the lateral line, and never extend significantly below it) are
distributed as follows: four predorsal (last just anterior to dorsal origin), two across
dorsal fin base, and three between the dorsal and adipose fins (these latter may be
faint or absent). There are six to seven dark rounded blotches or elongated ovals along
the lateral line, distributed as follows: first usually greatly elongate (sometimes
separated into two blotches, the posterior one being small and rounded) covering
lateral-line scales two to ten (if separated into two blotches, first on scales two to
seven, second on nine to ten); third (or second) blotch larger and more intensely
pigmented, lying on scales (including variation) 13-18; fourth blotch on scales
22-24; fifth blotch again darker, on scales 26—29; sixth blotch on scales 32-33,
seventh blotch large, on scales 36-38. Third, fifth and seventh blotches cover
lateral-line scales and extend half a scale row above and below, other blotches more
or less confined to lateral line. In larger individuals there is a tendency for bars over
dorsum to fade, while blotches along lateral line tend to elongate to form an
intermittent lateral stripe. Posterior fields of scales light, surrounded by darker
pigment. Both lips plicate.
Distribution
At present recorded only from the upper Xingu River, Amazon system (Fig. 14).
Knoppel (1972) records the gut contents of this species (listed as A. plicatus?
Eigenmann, 1912) as primarily filamentous algae, with plant remains, fungi, detritus,
sand and chitin remains included in the diet.
Etymology
Named intermedius (to be treated as a noun in apposition) in allusion to its
intermediate position in morphometric and colour pattern characteristics between
A. plicatus and A. spiloclistron on the one hand and the genus Pseudanos on the
other. (Note: this does not imply an intermediate phylogenetic position).
Anostomus plicatus Eigenmann, 1912
Fig. 15
Anostomus plicatus Eigenmann 1912:296 (original description, type locality:
Essequibo River, Guyana); Winterbottom 1974a (comparison with A. spiloclistron).
Diagnosis
A. plicatus may be separated from the monotypic anostomine genera by a
combination of 16 circumpeduncular scales and 4 teeth in each lower jaw. It is
distinguished from the striped Anostomus group (A. anostomus, A. brevior and
A. ternetzi) by possession of two to four blotches along lateral line and dark narrow
bars across dorsum. It is differentiated from Pseudanos and all remaining species of
Anostomus (except A. intermedius and A. spiloclistron) by truncate nature of
symphyseal lower jaw teeth (vs bicuspid), four branchiostegal rays (vs three), longer
snout to pelvic-fin origin (x = 56 per cent SL vs 51 per cent), shorter dorsal-fin origin
to caudal fin (51 per cent SL vs 54—55 per cent SL), longer snout (x = 44 per cent HL
vs 38-39 per cent), narrower interorbital (x = 33 per cent HL vs 35-38 per cent),
fewer lateral-line scales (x = 39 vs 42-45) and vertebrae (x = 36 vs 39-41).
Furthermore, at least some of narrow transverse bars across dorsum continue
ventrally well below lateral line, sometimes to ventral midline (vs just reaching lateral
line). It differs from A. spiloclistron in longer caudal peduncle (x = 14 percent SL vs
12 per cent — see Table 1) fewer lateral-line scales (x = 39 vs 41) and vertebrae
(x = 36 vs 38) and in narrower transverse bars across dorsum (one scale wide vs two
scales wide). It may be separated from A. intermedius by longer snout (x = 44 per
cent HL vs 40 per cent; Figs. 12 and 13), by possession of vertical pigmented areas
below midline (vs absent below midline) and in having more teeth on ceratobranchial
five and fifth pharyngobranchial tooth plate.
Description
A fusiform, somewhat compressed species of Anostomus (size range of specimens
examined 58-111 mm SL) with a colour pattern of spots, bars and bands. The
following measurements are expressed as percentages, and these and the meristic
values consist of a mean, the range in parentheses, the standard deviation and the
standard error respectively.
As percentage of standard length: lower jaw to anal-fin origin 82.9 (81.1—85.2),
0.013, 0.004; lower jaw to adipose-fin origin 88.0 (86.0-89.5), 0.013, 0.004; lower
jaw to dorsal-fin origin 52.8 (49.7—55.6), 0.017, 0.005; lower jaw to pelvic-fin origin
56.1 (53.4-60.1), 0.018, 0.005; dorsal-fin origin to caudal-fin origin 50.9
(48.2-53.0), 0.014, 0.004; dorsal-fin origin to adipose-fin origin 37.4 (35.3-40.8),
0.016, 0.005; caudal peduncle length 13.8 (12.5—15.7), 0.010, 0.003; head length
29.3 (27:2-32.2), 0.013, 0.004; body depth. .27.1 (25:2-31:2)) 0.018, {0:005;
peduncle depth 11.8 (11.2-12.3), 0.004, 0.001; body width 12.3 (6.8-14.1), 0.019,
0.006.
As percentage head length: preopercle length 74.0 (71.8-76.1), 0.011, 0.004;
snout length 43.9 (41.1-47.0), 0.014, 0.004; head depth 76.3 (70.6-82.1), 0.036,
0.010; preopercle depth 59.9 (56.6-64.0), 0.024, 0.007; snout depth 37.9
16
(34.4-41.2), 0.018, 0.005; eye diameter 23.4 (20.4-32.2) 0.031, 0.009; bony
interorbital 32.8 (29.0—35.6), 0.020, 0.006.
Lateral-line scales 38.6 (38-39), 0.463, 0.129; dorsal transverse 4.9 (4.5-5.5),
0.463, 0.129; ventral transverse 4.4 (4.04.5), 0.219, 0.061; predorsal 11.8 (11-13);
0.832, 0.231; dorsal to adipose 11 (10-13), 0.913, 0.253; adipose to caudal 6.7
(S—9), 1.109, 0.308; isthmus to pelvis 16.2 (15-18), 0.832, 0.231; pelvis to anus 8.9
(7-10), 0.954, 0.265; anal to caudal 6.7 (5-8), 0.751, 0.208; circumpeduncular 16.
Number of radii on scales (from below dorsal origin) increases with size, larger
examples show reticulations starting at focus of the scale. Angle between posterior
three primary radii about 90-180°. Lateral-line scales from below dorsal fin with a
very variable number of radii, some show reticulations (Fig. 7D).
Dorsal fin iii 10; caudal fin normally of 10 upper and 9 lower rays (once 9 and 8
respectively); anal fin 111 8; pelvic fin 1 8 (once i 7 on one side); pectoral fin i 12-1 16
(x = i 15.3, SD 0.925, SE 0.257). Number of olfactory lamellae increasing with
body size, from 32 in a 50 mm SL specimen to 48 in a specimen 110.9 mm SL.
Vertebrae 35.6 plus ural centrum (35-36, SD = 0.480, SE = 0.147), with 11-12
caudal including ural centrum. First pterygiophore of dorsal fin lies between tips of
eleventh and twelfth or, more commonly, twelfth and thirteenth, neural spines. Four
branchiostegal rays.
Teeth four in each half of each jaw. Upper jaw teeth biscuspid in inner two (but
prone to become worn down and truncated) and bi- to tricuspid in outer two. In lower
jaw, inner two teeth are usually truncated, outer two are bi- or tricuspid.
Colour pattern in alcohol consists of dark spots, bars (vertical stripes not crossing
midline) and bands (vertical strips across body) on a fawn background. Number of
bars/bands variable, there being up to 14 in large specimens; all less than one scale
wide. Four dark, somewhat elongated spots, one scale row wide on lateral line.
Including variation, they may cover lateral-line scales 4 to 5, 14-18, 25-28 and
35-38. There is no record of live colouration, although there is some evidence that
the centres of the scales are iridescent (Eigenmann, 1912; see Winterbottom, 1974a,
for discussion).
Distribution
This species is at present only recorded from the Essequibo River System, Guyana,
from Bartica near the mouth of the river to the savannah highlands drained by the
Kuyuwini and Rupununi Rivers and the headwaters of the Essequibo (Fig. 14). Géry
(1972-73) records A. plicatus from the upper Xingu River (a southern tributary of the
Amazon) but these specimens are A. intermedius.
Variation
Winterbottom (1974a) has shown that certain characters exhibit a growth inflection,
and suggested that this was due to the onset of sexual maturity. For example, a plot of
preopercle depth versus preopercle length shows a marked inflection. That this is not
a universal phenomenon in Anostomus is indicated by a comparison (of the same
characters) with A. anostomus, where no inflection is apparent.
17
Anostomus spiloclistron Winterbottom, 1974
Fig. 16
Anostomus_ spiloclistron Winterbottom, 1974a:154 (original description, type
locality: Nickerie River system, Surinam).
Diagnosis
A. spiloclistron is separated from the monotypic anostomine genera by combination
of 16 circumpeduncular scales and four teeth in each lower jaw. It differs from the
striped Anostomus group (A. anostomus, A. brevior and A. ternetzi) by possession of
a two to four blotches along lateral line and dark narrow bars across dorsum. It may
be distinguished from Pseudanos and all other species of Anostomus (except
A. intermedius and A. plicatus) by truncate nature of symphyseal lower jaw teeth (vs
bicuspid), four branchiostegal rays (vs three), longer snout to pelvic-fin origin
(x = 55 per cent SL vs 51 per cent), shorter dorsal-fin origin to caudal (x = 51 per
cent SL vs 54-55 per cent), longer snout (x = 43 per cent HL vs 38-39 per cent),
narrower interorbital (x = 31 per cent HL vs 35-38 per cent), fewer lateral-line scales
(x = 41 vs 42-45) and vertebrae (x = 38 vs 39-41) (Table 1). Further, at least some
of narrow transverse bars across dorsum continue ventrally well below lateral line,
sometimes to ventral midline (vs just reaching lateral line). It differs from A. plicatus
and A. intermedius in a shorter caudal peduncle (x = 12 per cent SL vs 14 per cent),
more lateral-line scales (x = 41 vs 39) and vertebrae (x = 38 vs 36) and in wider
transverse bars across dorsum (two scales wide vs one scale wide). It can be separated
from A. intermedius by longer snout (x = 43 per cent HL vs 40 per cent; Figs. 12 and
13), by presence of vertical pigmented areas below lateral line (vs absent) and in
having more teeth on ceratobranchial five and fifth pharyngobranchial tooth plate.
Description
A moderately elongate fusiform species of Anostomus (size range of specimens
examined 59-104 mm SL). The following measurements are expressed as
percentages, and these and the meristics consist of a mean, the range in parentheses,
the standard deviation and the standard error respectively.
As percentage of standard length: lower jaw to anal-fin origin 83.9 (82.1-85.4),
0.010, 0.003; lower jaw to adipose-fin origin 88.9 (86.8—90.2), 0.010, 0.003; lower
jaw to dorsal-fin origin 51.2 (49.8—-52.7), 0.007, 0.002; lower jaw to pelvic-fin origin
55.1 (53.6-57.2), 0.009, 0.002; dorsal-fin origin to caudal-fin origin 51.3
(49.4-53.4), 0.013, 0.003; dorsal-fin origin to adipose-fin origin 38.7 (36.0—-40.9),
0.014, 0.004; caudal peduncle length 11.5 (10.7—12.5), 0.005, 0.001; caudal
peduncle depth 11.6 (10.7-12.3), 0.005, 0.001; head length 29.1 (26.6-30.9),
0.012, 0.003; body depth 25.8 (24.2-29.7), 0.005, 0.001; body width 13.6
(12.2-15.9), 0.010, 0.003.
As percentage of head length: preopercle length 73.8 (71.3-76.6), 0.015, 0.004;
snout length 42.8 (41.6-45.1), 0.009, 0.002; head depth 69.1 (62.9-81.6), 0.058,
0.015; preopercle depth 54.0 (51.3-60.7), 0.028, 0.007, snout depth 33.9
(31.8-40.1), 0.024, 0.006; eye diameter 22.0 (19.6—23.5), 0.011, 0.003; bony
interorbital 31.3 (30.1-33.9), 0.012, 0.003.
18
Lateral-line scales 41.0 (40-42), 0.423, 0.109; dorsal transverse 5.5; ventral
transverse 4.5; predorsal 13.1 (12-14), 0.516, 0.133; dorsal to adipose 12.2 (11-14),
0.775, 0.200; adipose to caudal 7.0 (6-8), 0.378, 0.098; isthmus to pelvis 16.1
(15-17), 0.516, 0.133; pelvis to anus 11.2 (10-12), 0.561, 0.145; anal to caudal 6.6
(6-7), 0.507, 0.131; circumpeduncular 16. Scales from row above lateral line and in
line with origin of dorsal fin with four radii in small specimens, increasing irregularly
in number with increasing size, reticulations appear at the focus in larger specimens.
Lateral-line scales as for A. plicatus.
Dorsal fin iii 10 or iv 9 (twice iii 9), caudal fin with ten upper and nine lower
principal rays (once 10/10); anal fin iii 8, pelvic fins each i 8, pectoral fin i 15.0 (i
13-1 16), 0.945, 0.244. Number of olfactory lamellae increasing with body size,
from about 30 at 60 mm SL to about 42 in specimens longer than 100 mm SL.
Vertebrae 37.6 (37-38), 0.507, 0.131, plus ural centrum, with 12-13 caudal
including ural centrum (once 11). First pterygiophore of dorsal fin inserting between
neural spine tips of twelfth and thirteenth vertebrae (once eleventh and twelfth;
holotype). Four branchiostegal rays.
Teeth orange-brown, four in each half of each jaw. In upper jaw inner three
bicuspid (although in specimens less than about 65 mm SL middle two teeth may be
tricuspid), outermost (most lateral), tooth is tricuspid. In lower jaw, inner two teeth
truncate, outer two being tricuspid. In specimens below about 60 mm SL, outer of
two truncate teeth may be bi- or even tri-cuspid.
Colour pattern in alcohol consists of dark spots, bars and bands on a light
background. There are four round spots centred on lateral line, covering scale rows
above and below lateral line; including variation the spots cover lateral-line scales 3
to 5, 13-18, 26-30 and 36—40. Bars and bands more variable. Bars normally present
above lateral-line scales 1, 3, 14, 18, 28, and sometimes 36. Bands cross lateral line
at scales 9, 22 and 33. Vertical pigmented areas that may form either bars or bands lie
at lateral-line scales 6, 11 and 25. Bars usually have a ventral counterpart. Some
individuals have light centres to scales.
Distribution
At present recorded only from the Fallawatra River of the Nickerie River system of
western Surinam, close to the Stondansie Falls, in wide stretches of river (60-80 m)
over sand and rock substrates (Fig. 14).
Variation
Certain characters show growth inflections apparently associated with the onset of
sexual maturity (as in A. plicatus).
Anostomus ternetzi Fernandez-Yepez, 1949
Fig. 17
Anostomus ternetzi Fernandez-Yepez 1949:293 (original description, type locality:
Orinoco River system); Géry 1960 (French Guiana); 1972/73 (upper Xingu River,
D’ Arcy Thomson deformation coordinates); Knoppel 1972 (diet).
Anostomus anostomus (non Linnaeus) — Myers 1950 (partim); Lowe 1964 (upper
Essequibo River system).
Diagnosis
A. ternetzi differs from all other anostomines (except A. anostomus and A. brevior)
in having dark lateral stripes on a light background. It can be separated from
A. anostomus by its (usually) longer caudal peduncle (Fig. 4), its three branchios-
tegal rays (vs four) and by a light median predorsal stripe (vs dark median predorsal
stripe). In addition to last two characters, which also separate it from A. brevior, it
differs from that species in having a less deep body and head (Figs. 5 and 6).
Description
An elongate, striped species of Anostomus (size range of material examined
37-100 mm SL). The following measurements are expressed as percentages, and
these and the meristics consist of a mean, the range in parentheses, the standard
deviation and the standard error respectively.
As percentage of standard length: lower jaw to anal-fin origin 81.2 (77.6—83.5),
0.013, 0.002; lower jaw to adipose-fin origin 87.4 (84.4—-89.0), 0.011, 0.002; lower
jaw to dorsal-fin origin 49.2 (47.4-51.6), 0.009, 0.002; lower jaw to pelvic-fin origin
51.9 (48.4-54.2), 0.011, 0.002; dorsal-fin origin to caudal-fin origin 52.8
(50.9-55.4), 0.010, 0.002; dorsal-fin origin to adipose-fin origin 39.4 (37.1-41.1),
0.010, 0.002; caudal peduncle length 13.9 (10.1-16.0), 0.011, 0.002; caudal
peduncle depth 10.2 (9.2-11.4), 0.006, 0.001; head length 26.0 (24.3-29.9), 0.011,
0.002; body depth 20.9 (18.8—-22.9), 0.012, 0.002; body width 11.6 (10.0-13.2),
0.008, 0.002.
As percentage head length: preopercle length 73.5 (70.1-75.8), 0.014, 0.002;
snout length 40.3 (34.4-43.6), 0.022, 0.004; head depth 61.5 (53.6-68.6), 0.034,
0.006; preopercle depth 50.8 (45.9-53.7), 0.018, 0.003; snout depth 32.8
(30.2-36.3), 0.014, 0.002; eye diameter 22.6 (19.8-25.6), 0.015, 0.002; bony
interorbital 31.6 (28.9-34.3), 0.011, 0.002.
Lateral-line scales 40.2 (39-42), 0.516, 0.084; dorsal transverse 4.6 (4.5—5),
0.223, 0.036; ventral transverse 3.8 (3.5-4), 0.250, 0.041; predorsal 12.3 (11-14),
0.694, 0.113; dorsal to adipose 13.0 (12-15), 0.676, 0.135; adipose to caudal 7.4
(6-9), 0.700, 0.140; isthmus to pelvis 16.8 (15-18), 0.851, 0.170; pelvis to anus
10.3 (9-11), 0.503, 0.082; anal to caudal 7.3 (6-8), 0.542, 0.108; circumpeduncular
16. Scales (from below dorsal origin) with four radii at right angles to each other in
small (and sometimes large) individuals, with a tendency to increase number of radii
with size. Reticulations often present in larger specimens (>62 mm SL). Lateral-line
scales with a variable number of radii and sometimes a few reticulations.
Dorsal fin usually iii 10 (iv 9 three times, iii 9 once), caudal fin usually with 10
upper and 9 lower principal rays (once 9/9); anal iii 8 (once iii 7); pelvic i 8; pectoral 1
13.7 (11-15), 0.653, 0.106. Number of olfactory lamellae increasing with specimen
size, from 18 at 36.8 mm SL to 38 at 71.0 mm SL. Vertebrae usually 37 + ural
centrum (with 12-13 caudal including ural centrum), range 37-38, x = 37.3
(n = 21). Pterygiophore of first dorsal fin ray lies between neural spine tips of
eleventh and twelfth or more commonly twelfth and thirteenth vertebrae. Three
branchiostegal rays.
20
Teeth orange-brown, four in each half of each jaw. In upper jaw innermost two
teeth on each side bicuspid, third tooth tricuspid, and outermost (most lateral) may
have three or four cusps. Same applies to outermost tooth in lower jaw, other three
teeth tricuspid. In one specimen (MZUSP 9989, 74.0 mm SL) all teeth in both jaws
were truncate.
Colour pattern in alcohol consists of a series of dark longitudinal stripes on a light
background. A thin light band passes from between nostrils to dorsal fin origin in
middorsal line. This band flanked by a series of four poorly defined dark stripes,
which are separated only by light spots in centre of each scale, thus forming a string
of spots down each scale row. These become diffuse below dorsal fin, and region
posterior to the dorsal fin is dark. A light stripe about one scale wide and centred
between two scale rows above the lateral line, passes from top of eye to base of
caudal fin. Ventral to light stripe, midlateral dark stripe begins at anterior margin of
lower jaw, passes posteriorly through eye, across opercle and along lateral line to
caudal base; it covers lateral-line scale row and half scale of rows above and below
lateral line. Ventrolateral dark stripe begins on preopercle below eye, crosses
subopercle and pectoral fin base, joins stripe from other side at anal fin, and continues
posteriorly to base of caudal fin as a single median stripe; it is about one scale wide,
centred on third scale row below lateral line. Midventral stripe starts at isthmus and
passes posteriorly to anus. From pectoral fin area to origin of pelvic fins, it is
separated into two lateral halves by a narrow, median white strip. Base of the adipose
fin in all specimens is black, and marginal scales of caudal fin dark.
Distribution
A. ternetzi appears to be more or less confined to the eastern half of South America
(Fig. 8). I have examined specimens from the Orinoco River system, from the upper
Essequibo system, the headwaters of the Rio Branco (which drains into the Amazon
via the Rio Negro), from the Tapajos River which flows northwards to the Amazon,
from the upper Xingu River and from the mouth of the Tocantins River (which
reaches the sea just south of the mouth of the Amazon). Géry (1960) reports
specimens from the upper Maroni basin of French Guiana, as well as from the
Araguaia, a tributary of the Tocantins (Géery, 1972/73).
Variation
Sex was determined in a single sample of 12 specimens (MZUSP 9990). Results
indicate that the depth of the caudal peduncle is less in females than in males, but the
difference does not appear to be as clear cut as it is in A. anostomus.
Genus Gnathodolus Myers 1927
Gnathodolus Myers 1927:108 (type by original designation G. bidens Myers).
Diagnosis
The genus may be distinguished from all other anostomines by its deep body (head
21
depth 80-90 per cent head length) and by the presence of a single cusped tooth in the
lower jaw (vs 3-4 lower jaw teeth). In addition, it has a deeper caudal peduncle
(x = 13 per cent SL vs 9-12 per cent), a longer snout to preopercle length (x = 81
per cent HL vs 70-75 per cent), a greater head depth (x = 88 per cent HL vs 62-81
per cent), snout depth (x = 51 per cent HL vs 33-45 per cent) and interorbital width
(x = 40 per cent HL vs 32-38 per cent). It differs from other two monotypic genera
(Synaptolaemus and Sartor) in possessing 16 circumpeduncular scales. It shares with
these genera (but differs from Pseudanos and Anostomus) a longer caudal peduncle
(x = 16-17 per cent SL vs 12-14 per cent), fewer vertebrae (x = 35 vs 36-41) and
presence of rounded or conical dermal papillae on lower jaw (Fig 19). It shares with
Sartor (but not Synaptolaemus, Pseudanos or Anostomus) a wider body (x = 16 per
cent SL for Sartor, 19 per cent for Gnathodolus vs 11-14 per cent) deeper preopercle
depth (70 per cent HL for Sartor, 75 per cent for Gnathodolus vs 51-64 per cent) and
greater eye diameter (x = 26 per cent HL for both vs 21-24 per cent). Gnathodolus
differs from Sartor in wider body and deeper preopercle depth. (See above.)
Gnathodolus bidens Myers, 1927
Fig. 18
Gnathodolus bidens Myers 1927:108 (original description, type locality: Casiquiare
River in region of bifurcation with Orinoco).
Diagnosis
As for genus.
Description
A deep-bodied form with a size range of material examined 73 to 109 mm SL. As
only three specimens were available for study, data will be presented as a mean
followed by the range in parentheses.
As percentage standard length: lower jaw to anal-fin origin 79.1 (76.0-81.9),
lower jaw to adipose-fin origin 84.9 (84.0—85.7), lower jaw to dorsal-fin origin 49.4
(49.0-49.7); lower jaw to pelvic-fin origin 51.8 (49.0-53.3); dorsal-fin origin to
caudal base 55.0 (53.5-57.0); dorsal-fin origin to adipose-fin origin 38.3
(37.6-39.0); peduncle length 16.0 (15.3-16.6); peduncle depth 13.3 (13.1-13.7);
head length 30.6 (30.0—-31.3); body depth 30.0 (29.0-30.7); body width 19.3
(14.8-26.2).
As percentage of head length: preopercle length 81.4 (77.3-87.0); snout length
44.6 (43.0-45.8); head depth 87.6 (85.8—90.0); preopercle depth 74.5 (70.0-78.2);
snout depth 51.0 (45.8-54.1); eye diameter 25.9 (25.6~26.2); bony interorbital 40.3
(38.8-42.0).
Lateral-line scales 39; dorsal transverse 5.5; ventral transverse 4.5; predorsal 11.0
(10-12); dorsal to adipose 11.0 (10-12); adipose to caudal 9.3 (9-10); isthmus to
pelvis 16.0 (14-18); pelvis to anus 8.7 (8-9); anal to caudal 9; circumpeduncular 16.
Scales (from below dorsal origin and one row above lateral line) with a variable
number of radii increasing with size, reticulations at focus in larger individuals.
IL
Lateral-line scales similar to P. irinae, with no radii along lateral-line tubule and no
reticulations.
Dorsal fin iii 10, caudal with 10 upper and 9 lower principal rays, anal iii 8, pelvic i
8 (once i 7, one side only); pectoral i 15 (i 14-1 16). Vertebrae 35 + urostyle, with 13
caudal (including urostyle) and first pterygiophore of dorsal fin inserting between
neural spines of tenth and eleventh vertebrae.
Four teeth in each upper jaw and one in lower. The upper jaw teeth have bluntly
lanceolate points with a hint of lateral cusps. Lower jaw tooth is greatly elongated,
with a sickle-shaped tip. It is somewhat recurved, with a concave posterior face. This
pair of teeth projects above upper jaw when mouth is closed.
Colour pattern dull brown with six to eight diffuse darker crossbars dorsal to but
not reaching lateral line. A diffuse black spot centred on lateral line below dorsal fin
and a smaller one dorsal to anal fin. In life, scales with indistinct, light centres,
suborbital area tinged with violet (Myers, 1927).
Distribution
Known only from the region of the Casiquiare/Orinoco bifurcation in Venezuela (Fig.
8).
Discussion
Myers (1950) reported that the paratype at the California Academy of Sciences (CAS)
had been mislaid. As can be seen from the list of material, it has subsequently been
located. The figure of the holotype (by Pablo Bravo) shows 10 ventral caudal rays, 7
branched pelvic fin rays and 32 lateral line scales (all incorrect). A radiograph of the
holotype does reveal the presence of an abnormal extra caudal fin ray, the base lying
above the lateral line but well removed from the distal end of hypural three. The
peculiar structure of the caudal fin commented on by Myers (1927, 1950) seems to
me to be due to injury (in spite of it occurring in two of the three types, the third
specimen with a damaged caudal), the fin rays showing very definite signs of
regeneration and previous injury. Radiographs also reveal the presence of a minute
nubbin of bone at the anterior of the anal fin, which may represent an unbranched fin
ray (giving a formula for the anal fin of iv 8).
Gnathodolus sp.
Fig. 19
Description
A single specimen referable to Gnathodolus was obtained by Mr. G. Howes of the
British Museum (Natural History). It may well represent a new species, but is not so
described since it is smaller than any of the types, there is only one specimen, and it
comes from the aquarium trade. (The dealer thought it was probably collected in
Columbia, Orinoco River system, Vichada River (G. Howes, pers.comm.).) It differs
from G. bidens in having fewer lateral-line scales (36/37) and in colour pattern.
Compared to G. bidens it has greater values for lower jaw to anal-fin origin (76.9 per
cent SL) and eye diameter (27.6 per cent HL), and lesser values for lower jaw to
23
dorsal fin origin (47.8 per cent SL); body depth (27.4 per cent SL); peduncle depth
(12 per cent SL); body width (14.8 per cent SL); snout length (39.3 per cent HL);
head depth (75.5 per cent HL); preopercle depth (66.3 per cent HL) and bony
interorbital (35.6 per cent HL).
Colour pattern in alcohol light yellow with about nine diffuse transverse bars across
dorsum which do not reach lateral line. First three (predorsal) bands narrow and
distinct, next two (bisected by dorsal fin) have a fair amount of pigment in interspace
between them and could be interpreted as a single broad bar with darker edges. Three
narrow bars present between dorsal and adipose fins and some indication of another
bar between adipose and caudal fins. Two dark spots on lateral line, one, larger,
beneath posterior base of dorsal fin and other below adipose fin origin. In addition a
dark spot in second scale row below fourth lateral line scale.
Dentary tooth has a bicuspid tip, with a posterior projection or cusp on shaft of
tooth (Fig. 19). Upper lip is plicate, while lower lip has conical papillae also found in
Synaptolaemus and Sartor. Mr. Howes informs me that he observed this specimen in
an aquarium removing scales from the flanks of a large Schizodon sp.; it also took
commercial flake fish food.
Genus Pseudanos gen. nov.
Schizodon trimaculatus Kner 1859:161 (type species).
Diagnosis
Pseudanos differs from the monotypic anostomines (Gnathodolus, Sartor, Synap-
tolaemus) by a combination of 16 circumpeduncular scales and 4 teeth in each half of
lower jaw. Bony portion of lower jaw is as long as it is wide, and lower lip is plicate
(without conical or rounded dermal papillae). It may be differentiated from
Anostomus by presence of three branchiostegal rays (except for A. ternetzi, species of
Anostomus have four), and in having 41 or more lateral-line scales and 39 or more
vertebrae (vs 40 or fewer lateral-line scales and 38 or fewer vertebrae). The numerous
osteological differences between these two genera are described in the Discussion
section of this paper.
Etymology
Derived from pseudo (false) and the first four letters of the generic name Anostomus,
in allusion to the very similar external appearance of the two genera. Gender:
masculine.
Pseudanos gracilis Kner, 1859
Fig. 20
Schizodon gracilis Kner 1858:160 (original description, type locality: Rio Guapore,
Brazil).
Anostomus gracilis — Myers 1950 (new record from Orinoco drainage); Knoppel
1972 (diet).
24
Diagnosis
P. gracilis may be distinguished from the monotypic Gnathodolus, Sartor and
Synaptolaemus by a combination of 16 circumpeduncular scales and a lower jaw with
four teeth. It is distinguished from striped Anostomus group in that it has two to four
round blotches or a single dark horizontal stripe along lateral line (never more than
one stripe). It can be separated from spot-barred species (P. irinae, P. trimaculatus,
A. plicatus, A. intermedius and A. spiloclistron) in that it never has narrow
transverse bars across dorsum. It has a generally more slender and narrower body
(body depth x = 23 per cent SL vs 26-27 per cent; body width x = 11 percent SL vs
12-14 per cent; Table 1), and it has an angle between posterior three radii of scales
(from row below dorsal fin origin and just above lateral line) of 40—90° (vs 110—180°
— compare Fig. 7, A and C with B). P. gracilis may be further differentiated from
A. plicatus and A. spiloclistron in having origin of pelvic fins nearer snout (sol
per cent SL vs 55—56 per cent), a greater dorsal-fin origin to caudal-fin distance (x =
54 per cent SL vs 51 per cent), a shorter snout (x = 39 per cent HL vs 43-44 per
cent), wider interorbital (x = 35 percent HL vs 31-33 per cent), more lateral-line
scales (x = 45 vs 39-41) and vertebrae (x = 41 vs 37-38) — see Table 1 — and three
branchiostegal rays (vs four).
Description
A compressed fusiform species of Pseudanos, size range of material examined
41-161 mm SL. The following morphometrics are expressed as percentages, and
these and the meristics consist of a mean, the range in parentheses, the standard
deviation, and the standard error respectively.
As percentage of standard length: lower jaw to anal-fin origin 81.0 (79.6-83.9),
0.010, 0.002; lower jaw to adipose-fin origin 86.6 (85.1—88.8), 0.008, 0.002; lower
jaw to dorsal-fin origin 48.6 (46.3—53.0), 0.016, 0.005; lower jaw to pelvic-fin origin
50.9 (48.4-54.9), 0.018, 0.004; dorsal-fin origin to caudal-fin origin 54.4
(49.9-57.4), 0.019, 0.004; dorsal-fin origin to adipose-fin origin 39.6 (35.9-42.6),
0.015, 0.003; peduncle length 12.7 (11.0-14.1), 0.008, 0.002; peduncle depth 9.4
(8.4-10.2), 0.005, 0.001; head length 26.3 (23.5—30.1), 0.021, 0.004; body depth
22.9 (18.3-25.4), 0.020, 0.004; body width 11.2 (10.4-11.9), 0.011, 0.008.
As percentage of head length: preopercle length 71.8 (68.4-76.4), 0.017, 0.003;
snout length 38.5 (35.0-42.6), 0.021, 0.004; head depth 73.5 (57.5—85.8), 0.079,
0.016; preopercle depth 59.7 (51.1-67.5), 0.043, 0.008; snout depth 38.0
(29.8-45.8), 0.037, 0.007; eye diameter 24.1 (19.7-31.3), 0.024, 0.005; bony
interorbital 35.0 (29.8-40.2), 0.024, 0.005.
Lateral-line scales 44.8 (43-47, the latter value from a specimen with a distorted
lateral line on one side), 0.791, 0.115; dorsal transverse 5.0 (4.5—5.5), 0.141, 0.028;
ventral transverse 4.0 (44.5), 0.098, 0.019; predorsal 13.4 (11-15), 0.852, 0.167;
dorsal to adipose 14.5 (14-15), 0.707, 0.500; adipose to caudal 7.5 (7-8), 0.707,
0.500; isthmus to pelvis 17.5 (17-18), 0.707, 0.500; pelvis to anus 12.9 (11-14),
0.816, 0.160; anal to caudal 7.0 (6-8), 1.414, 1.000; circumpeduncular 16. Scales
(from below dorsal origin) usually with three primary radii close together (between
40-90° apart, see Fig. 7B) on posterior field, one to middle of anterior field
(45.7-136.4 mm SL). However, occasional specimens have scales with more
25
numerous radii and a few reticulations around focus (86.2 and 160.5 mm SL).
Lateral-line scales with three radii, otherwise similar to A. anostomus (Fig. 7A).
Dorsal fin iii 10, caudal fin with ten upper (once nine) and nine lower principal
rays, anal iii 8, pelvic i 8, pectoral 1 13-1 16 (x = 113.9), 0.657, 0.129. Olfactory
lamellae increasing in number with body size, 22 (41.1 mm SL) to 56 (152.5 mm
SL). Vertebrae usually 41 + ural centrum, (with 13 caudal including ural centrum),
range 40-42, SD = 0.535, SE = 0.189. First pterygiophore of dorsal fin lies between
neural spines of twelfth and thirteenth or thirteenth and fourteenth vertebrae. Three
branchiostegal rays.
Four teeth in each half of each jaw. In upper jaw, all tricuspid (medial two teeth
sometimes bicuspid). In lower jaw medial two teeth bicuspid, next tooth tricuspid,
lateralmost tooth with four cusps. The cusps tend to wear down very rapidly, for in a
91.3 mm SL specimen cusps are not evident and teeth are truncate.
Colour pattern in alcohol variable. There are usually 11 thin stripes on body, these
produced by elongated dark spots in centre of each scale on a tan background. Stripes
thus pass along centre of each scale row. Median predorsal stripe present. Many
specimens exhibit dark spots on the flanks between lateral-line scale row and row
ventral to it. Number of spots is somewhat variable (first is sometimes absent, and
third indistinct). Including individual variation, first spot covers lateral-line scales 4
to 6, second 16-18, third 30—32 and fourth 41-45. In other individuals, spots may be
replaced by a dark stripe which extends from shoulder girdle to caudal peduncle
between lateral line and scale row below. No specimens with both a dark stripe and
spots have been seen; in any collection, all specimens have either one or the other
colour pattern only. Specimens from the bifurcation of the Orinoco at Laja Tama
Tama and a single specimen from the Orinoco at Caicara have the dark stripe and no
spots. However, specimens from a locality on the Orinoco between the above
collection sites (at San Fernando where the Atabapo joins the Orinoco) have no dark
stripes, but do possess the four dark spots. I can find no differences whatsoever in the
morphometric or meristic data to justify separation at any taxonomic level. Whether
the colour difference is ecophenotypic, genetic or due to some other factor(s) must
await extensive collecting and monitoring of environmental conditions. Colour in life
is partly opposite that in alcohol. In two Kodachromes of aquarium specimens (one
by S. H. Weitzman & W. L. Fink, USNM uncat., the other by K. Paysan, courtesy of
TFH Publications) the centres of the scales are an almost iridescent yellow. In the
USNM specimen, the lateral line is dark grey, as is the rest of the fish, the dorsal and
caudal fins being tinged with red. On preservation, this specimen exhibited the dark
lateral stripe with elongated dark spots in the centres of the scales on a light tan
background. In Paysan’s specimen, on the other hand, the background colour is a
fairly light greenish-brown, four dark spots are present along the lateral line, and the
lateral line scales between these spots have light centres. The dorsal and caudal fins
and the mouth are red. I have not seen this specimen preserved.
Distribution
The vast majority of specimens in museum collections come from the Orinoco River
system (Fig. 14). The species is, however, known from a number of localities in the
Amazon system (San Carlos de Rio Negro, on the Negro River near the mouth of the
Casiquaire Canal, from Manaus on the Negro, and from the type locality the Guaporé
River, which drains into the Amazon via the Madeira River). Knoppel (1972)
26
reported on the diet of specimens from Igapou Castanha (mid-region of the Negro)
which consisted mainly of plant remains, as well as fungi, algae, detritus, sand,
chiton remains and terrestrial insects.
Pseudanos irinae sp. nov.
Fig. 21
Anostomus trimaculatus (non Kner, 1859) Eigenmann 1912 (Essequibo River);
Myers 1950 (upper Orinoco); Ramirez 1957 (Venezuela); Mago-Leccia 1970
(Venezuela).
Diagnosis
P. irinae may be distinguished from Gnathodolus, Sartor and Synaptolaemus by a
combination of 16 circumpeduncular scales and four lower jaw teeth. It may be
distinguished from the striped Anostomus group (A. anostomus, A. brevior and A.
ternetzi) by the presence of two to four rounded blotches along the lateral line, and
narrow transverse bars across the dorsum. It can be separated from A. plicatus,
A. intermedius and A. spiloclistron by cusped nature of symphyseal lower jaw teeth
(vs truncate), pelvic origin closer to snout (x = 51 per cent SL vs 55—56 per cent),
dorsal-fin origin to caudal fin distance greater (x = 55 per cent SL vs 51 per cent), a
shorter snout length (x = 39 per cent HL vs 43-44 per cent), a wider interorbital
(x = 38 per cent HL vs 31-33 per cent), more lateral-line scales (x = 43 vs 39-41)
and vertebrae (x = 40 vs 36-38) and three (vs four) branchiostegal rays. It differs
from P. gracilis in having a deeper (x = 26 per cent SL vs 23 per cent) and wider
(x = 13 percent SL vs 11 per cent) body, generally having two less lateral-line scales
(x = 43) and one less vertebra (x = 40) (Table 1), presence of narrow dark
transverse bands across dorsum, and an angle of 110—180° between three posterior
scale radii (vs 40-90°). It can be separated from P. trimaculatus in its usually
narrower body (x = 13 per cent SL vs 14 per cent, Fig. 22), average of one more
lateral-line scale (43) and vertebra (40), and by a dark spot in centre of each scale (vs
a light spot).
Description
A fusiform, somewhat compressed species of Pseudanos with a colour pattern of
spots and bars, and a size range of material examined of 54-100 mm SL. The
following measurements are expressed as percentages, and these and the meristic
values consist of a mean, the range in parentheses, the standard deviation and the
standard error respectively.
As percentage of standard length: lower jaw to anal-fin origin 81.3 (78.7-83.7),
0.011, 0.002; lower jaw to adipose-fin origin 86.8 (84.6-89.3), 0.009, 0.001; lower
jaw to dorsal-fin origin 49.3 (46.9-51.1), 0.011, 0.001; lower jaw to pelvic-fin origin
51.3. (48.4-53.9), 0.012, 0.002; dorsal-fin origin to caudal-fin origin 55.0
(52.9-57.7), 0.010, 0.001; dorsal-fin origin to adipose-fin to origin 40.3
(37.4-43.4), 0.012, 0.002; caudal peduncle length 13.1 (11.8—14.7), 0.006, 0.001;
peduncle depth 10.4 (9.4-11.8), 0.005, 0.001: head length 27.2 (24.8-29.1), 0.008,
a6 |
0.001; body depth 26.4 (23.7-28.9), 0.010, 0.001; body width 13.0 (11.9-14.7),
0.006, 0.001.
As percentage of head length: preopercle length 70.3 (65.6—75.5), 0.020, 0.003;
snout length 38.0 (34.0-41.9), 0.016, 0.002; head depth 81.5 (73.4—-92.5), 0.039,
0.005; preopercle depth 63.7 (57.6-69.0), 0.027, 0.004; snout depth 37.9
(33.8-42.6), 0.017, 0.002; eye diameter 24.4 (20.3-28.7), 0.019, 0.003 (Fig. 23);
bony interorbital 37.5 (34.5-41.2), 0.014, 0.002.
Lateral-line scales 43.2 (41-45), 1.047, 0.136; dorsal transverse 5.5, ventral
transverse 4.5 (4.5—-5.0), 0.091, 0.012; predorsal 13.2 (11-15), 0.760, 0.010; dorsal
to adipose 13.2 (11-14), 0.690, 0.092; adipose to caudal 8.5 (7-10), 0.572, 0.077;
isthmus to pelvis 17.1 (14-20), 1.257, 0.168; pelvis to anus 11.6 (10-13), 0.689,
0.090; anal to caudal 7.7 (6-9), 0.570, 0.076; circumpeduncular 16. Scales (from
below dorsal origin) with four primary radii (three in posterior field), occasionally
developing a few reticulations around focus in larger individuals. Lateral-line scales
with 2-4 radii (Fig. 7C) none of which follow along lateral-line tube (as in
A. anostomus).
Dorsal fin 111 10 (iv 10 and iv 9 twice each), caudal fin of 10 dorsal and 9 ventral
principal rays (once with nine dorsal rays), anal fin 111 8 (twice 111 7), pelvic fins 1 8
(twice i 7), pectoral fin i 13-1 16 (x = 14.2). Olfactory lamellae increasing with
body size, from 22 in a 53 mm SL specimen to 36 in an individual of 100.3 mm SL.
Vertebrae 39-41 + ural centrum (x = 40.0, SD = 0.894, SE 0.70) with 12-14
(x = 12.8) caudal including ural centrum. First pterygiophore of dorsal fin inserts
between neural spines of twelfth and thirteenth vertebrae. Three branchiostegal rays.
Teeth orange-brown, four in each half of each jaw. Considerable range in number
of cusps that may be present. In upper jaw, innermost two teeth may have one to three
(usually three) cusps, third tooth with two to four (usually three) cusps, outer
(lateralmost) tooth with three to five cusps. In lower jaw, innermost two teeth with
two to three (usually two) cusps, third tooth with three to four (usually three) cusps,
and outer (lateralmost) tooth with four to five cusps.
Colour in alcohol yellow brown, paler below, with two to four dark spots or
blotches along lateral line, covering scales three to five (this spot lying partly beneath
lateral line) 16-19, 29-30 and 41-46. First and third spots may be faint or absent.
There is an indication in preserved specimens that spots are ocellated, the area around
them in some individuals being lighter than general background. Each scale has a
small dark spot lying beneath focus, the spots are darker ventrally. Dorsum crossed
by a variable number of irregular dark bars, some of which may reach lateral-line
scale row. There are usually five predorsal bars (posteriormost lying just in front of
dorsal origin), two bars bisected by dorsal fin, about five between dorsal and adipose
fins and one posterior to adipose. These more posterior bars may be faint or absent.
Distribution
The species has been recorded from the middle and upper reaches of the Orinoco
River and throughout the Essequibo River system in Guyana (Fig. 14).
Etymology
The species is named for my wife, Irina.
28
Pseudanos trimaculatus (Kner, 1859)
Fig. 24
Schizodon trimaculatus Kner 1859:161 (original description, type locality: Mato
Grosso).
Anostomus trimaculatus — Myers 1950 (partim—Peru); Géry 1961 (parts of cranial
osteology, scales, teeth); Knoppel 1972 (diet).
Diagnosis
P. trimaculatus may be distinguished from Gnathodolus, Sartor, and Synaptolaemus
by a combination of 16 circumpeduncular scales and four teeth in each lower jaw. It
may be separated from striped Anostomus (A. anostomus, A. brevior and A. ternetzi)
by presence of two to four rounded blotches along lateral line and narrow transverse
bars across dorsum. It differs from A. plicatus, A. intermedius, and A. spiloclistron
in cusped nature of the symphyseal lower jaw teeth (vs truncate), pelvic origin closer
to the snout (x = 51 per cent SL vs 55-56 per cent), a greater dorsal-fin origin to
caudal-fin distance (x = 55 per cent SL vs 51 per cent), a shorter snout length
(x = 38 per cent vs 43-44 per cent), a wider interorbital (x = 38 per cent HL vs
31-33 per cent), more lateral-line scales (x = 42 vs 39-41) and one more vertebra
(x = 39 vs 36-39) — see Table 1 — and three (vs four) branchiostegal rays. It differs
from P. gracilis in having a deeper (x = 26 per cent SL vs 23 per cent) and wider
(x = 14 per cent SL vs 11 per cent) body, generally having three fewer lateral-line
scales (x = 42 vs 45) and two less vertebrae (x = 39 vs 41), presence of narrow dark
transverse bars across dorsum, and an angle of 110—180° between three posterior
scale radii (vs 40—-90°). It can be differentiated from P. irinae by its usually wider
body (x = 14 per cent SL vs 13 per cent — Fig. 22), average of one less lateral-line
scale (42) and vertebrae (39), and by light spots in centre of each scale (vs dark
spots).
Description
A large, rather deep-bodied species (size range of material examined 51-155 mm
SL), exhibiting considerable geographic variation. The following measurements are
expressed as percentages, and these and the meristics consist of a mean, the range in
parentheses, the standard deviation and the standard error respectively.
As percentage of standard length: lower jaw to anal-fin origin 81.0 (77.3-87.9),
0.016, 0.002; lower jaw to adipose-fin origin 86.5 (83.1—88.7), 0.012, 0.002; lower
jaw to dorsal-fin origin 49.4 (42.9-52.8), 0.015, 0.002; lower jaw to pelvic-fin origin
51.4 (47.8-57.0), 0.017, 0.002; dorsal-fin origin to caudal-fin origin 55.0
(51.6-59.5), 0.016, 0.002; dorsal-fin origin to adipose-fin origin 39.8 (33.4 44.6),
0.017, 0.002; caudal peduncle length 13.1 (11.8-15.0), 0.008, 0.001; caudal
peduncle depth 10.4 (8.8—-11.8), 0.007, 0.001; head length 27.7 (21.2-31.7), 0.017,
0.003; body depth 26.3 (19.2—32.7), 0.032, 0.005; body width 13.8 (10.8-16.6),
0.016, 0.003.
As percentage of head length: preopercle length 69.9 (64.1—79.9), 0.028, 0.004;
snout length 37.5 (31.6-44.4), 0.024, 0.004; head depth 80.3 (60.7—99.3), 0.086,
0.012; preopercle depth 63.0 (48.8—-74.4), 0.049, 0.007; snout depth 37.7
(31.6-44.1), 0.026, 0.004; eye diameter 24.4 (20.2—29.6), 0.021, 0.003; bony
interorbital 38.1 (33.9-43.5), 0.018, 0.003.
29
Lateral-iine scales 42.4 (41-44), 0.837, 0.120, dorsal transverse 5.5 (4.5-6.5),
0.411, 0.059; ventral transverse 4.5 (4-5), 0.103, 0.015; predorsal 12.3 (11-14),
0.663, 0.096; dorsal to adipose 12.8 (12-14), 0.787, 0.149; adipose to caudal 8.2
(7-10), 0.892, 0.172; isthmus to pelvis 17.1 (15-19), 1.031, 0.195; pelvis to anus
11.5 (10-13), 0.688, 0.100; anal to caudal 7.5 (6-9), 0.700, 0.135; circumpeduncu-
lar 16. Scales (from scale row above lateral line and below dorsal origin) usually with
four radii (posterior three together forming an angle of about 180°). Number of radii
may increase somewhat with body size, but reticulations are seldom present even in
large specimens. Lateral-line scales usually with two to three (seldom four) radii,
otherwise as for P. irinae.
Dorsal fin iii 10 (occasionally iv 9, once iv 10), caudal fin usually with 10 dorsal, 9
ventral principal rays (seldom 9 dorsal and/or 8 ventral rays), anal iii 8 (once iii 6),
pelvic i 8 (twice i 7 on one side only), pectoral i 12-i 15 (x = 13.9, SD = 0.698,
SE = 0.100). Number of olfactory lamellae increasing with body size, from 22 at
48 mm SL to 36 at 102 mm SL. Vertebrae usually 39 + urostyle (x = 39.1, range
38-41, SD = 0.704, SE = 0.182) with 12-13 (x = 12.3) caudal including urostyle.
First pterygiophore of dorsal fin inserts between neura spines of eleventh-twelfth or
twelfth—thirteenth vertebrae. Three branchiostegal rays.
Teeth orange-brown, four in each half of each jaw. There is some variation in
number of cusps. In upper jaw, inner (medial) two teeth bicuspid, third tooth
tricuspid, outer (lateralmost) tooth with four to five cusps. In lower jaw, medial two
teeth tricuspid, third tooth tricuspid (once with four cusps), lateralmost tooth with
four to five cusps.
Colour in alcohol yellow-brown, paler below, with 2 to 4 dark spots along lateral
line, covering scales 3 to 5 (this spot usually somewhat below, but touching, lateral
line) 16-19, 29-30 and 40-44. First and third spots may be faint or absent, while
second is usually ocellated with a lighter pigmentation than general background. Each
scale with small light-coloured spot beneath focus. Dorsum is crossed by a variable
number of irregular dark bars, some of which reach lateral line. There are about five
predorsal bars (posteriormost lying just in front of dorsal-fin origin), two bars
bisected by dorsal fin, about five between dorsal and adipose fins and one posterior to
adipose, more posterior bars may be faint or absent. In young specimens (ca 40 mm
SL) these crossbars have appearance of being formed by development of a light area
in middle of a dark crossbar, edges of which remain dark and thus form two narrow
bars.
Distribution
P. trimaculatus is found throughout the Amazon river system and its major tributaries
(Fig. 14). It is probably this species (and not P. irinae) which has been found in the
Rio Negro; Knoppel (1972) reports on the stomach contents of three specimens
(primarily fruit with some plant remains) from this region. Ringuelet et al. (1967)
report on a single specimen from Lago Itati, Corrientes River, River Parana system of
Argentina (about 28°40’S, 58°W). This is the furthest south any anostomine has been
recorded.
Variation
There are some very difficult problems associated with the specimens here grouped
30
under P. trimaculatus. Grouping the specimens geographically into Mato Grosso (20
specimens), Peruvian (13; region of Nanay and Napo River mouths), Ecuadorian (13)
and eastern Amazonian (5) populations, reveals fairly considerable variation. Of
these, the eastern Amazon population appears to deviate most from the other three.
Unfortunately only five specimens from this region were available for study and it is
quite possible that these differences are more apparent than real. Graphic analysis
indicates that this population has the dorsal, anal, and pelvic (Fig. 25) fins closer to
the tip of the lower jaw (R? = 0.92, 0.91 and 0.97 respectively), a less deep body
(Fig. 26) and head (R? = 0.51 and 0.74 respectively), shorter head length
(R? = 0.84), larger eye (R? = 0.87, Fig. 23) and a longer caudal peduncle (Fig. 27,
? = 0.95). Less variation is apparent in the other populations. Specimens from the
Mato Grosso have a somewhat longer snout and lower jaw-to-preopercle distance
(R? = 0.96 and 0.97 respectively), while Peruvian examples have a somewhat
smaller eye (R? = 0.84, Fig. 23). Peruvian and Ecuadorian specimens have a greater
depth at the preopercle (R? = 0.96 for both) and a longer head (R* = 0.93 and 0.99
respectively). None of these differences is statistically significant in an analysis of
variance utilizing the F-test.
Genus Sartor Myers and de Carvalho 1959
Sartor Myers and de Carvalho 1959:148 (type by original designation S. respectus
Myers and de Carvalho).
Diagnosis
The genus may be recognized from all other anostomines by possession of three teeth
in lower jaw (vs one or four). In common with Gnathodolus and Synaptolaemus it
differs from Anostomus and Pseudanos in having a longer caudal peduncle
(x = 16-17 per cent SL vs 12-14 per cent), fewer vertebrae (x = 35 vs 36-41),
enlarged symphyseal teeth in lower jaw, bony part of which is longer than wide (vs
subequal teeth in lower jaw which is about as long as wide) and rounded or conical
dermal papillae on lower jaw. It shares with Gnathodolus (but not Anostomus,
Pseudanos or Synaptolaemus) a wider body (x = 15 per cent SL for Sartor, 28 per
cent for Gnathodolus vs 11-14 per cent), and a lower jaw (bony structure minus
teeth) five times as long as it is wide. Sartor differs from Gnathodolus in having a less
wide body and less deep body, head and preopercle (see Table 1), as well as
possessing three teeth in each half of lower jaw (vs 1). It shares with Synaptolaemus
12 circumpeduncular scales (vs 16 in Anostomus, Pseudanos and Gnathodolus).
Sartor respectus Myers and de Carvalho, 1959
Fig. 28
Sartor respectus Myers and de Carvalho 1959:149 (original description, type
locality: upper Xingu River, Brazil); Géry 1961 (aspects of cranial osteology);
1972/73 (redescription from four additional specimens from upper Xingu, D’ Arcy
Thompson deformation coordinates); Knoppel 1972 (diet).
31
Diagnosis
As for genus.
Description
A somewhat compressed species (size range of material examined 60-80 mm SL),
with a very narrow and elongate lower jaw. Since only three specimens were
available for a study, the following counts and measurements (as percentages) are
expressed as a mean followed by the range in parentheses.
As percentage of standard length: lower jaw to anal-fin origin 76.1 (75.7—76.7);
lower jaw to adipose-fin origin 84.5 (83.3—85.8); lower jaw to dorsal-fin origin 49.2
(48.4-49.6); lower jaw to pelvic-fin origin 52.3 (52.0-52.7); dorsal-fin origin to
caudal-fin origin 53.1 (52.8—-53.3); dorsal-fin origin to adipose-fin origin 35.8
(35.7-35.9); caudal peduncle length 18.7 (18.0-20.1); caudal peduncle depth 10.8
(10.7—11.0); head length 30.0 (29.7—30.3); body depth 23.7 (22.5—25.3); body width
14.7 (14.0-16.0).
As percentage of head length: preopercle length 74.7 (72.5—76.9); snout length
43.0 (41.6-45.6); head depth 68.1 (66.9-68.8); preopercle depth 59.4 (59.0-60.3);
snout depth 41.5 (40.2-43.3); eye diameter 21.3 (20.6—22.5); bony interorbital 39.3
(37.740. 2).
Lateral-line scales 39.3 (39-40); dorsal transverse 5; ventral transverse 4; predorsal
13.3 (12-14); dorsal to adipose 11.7 (11-12); adipose to caudal 8.7 (8-9); isthmus to
pelvis 17.7 (17-19); pelvis to anus 7.3 (7-8); anal to caudal 9.0 (810);
circumpeduncular 12. Scales (from scale row above lateral line and beneath dorsal-fin
origin) with up to seven radii in posterior field and five in anterior. A few
reticulations at focus.
Dorsal fin 111 10, caudal with 10 upper and 9 lower principal rays, anal iii 8, pelvic i
8, pectoral usually i 16 (once i 15), Vertebrae 35 plus ural centrum, with 14 caudal
(including urostyle). First pterygiophore of dorsal fin lies between neural spines of
tenth and eleventh vertebrae.
Teeth four in each half of upper jaw, three in each half of lower jaw. Upper jaw
teeth all bicuspid, with medial cusp larger (lateralmost tooth possibly tricuspid).
Symphyseal tooth of lower jaw greatly enlarged, awllike, no cusps, a somewhat
concave posterior surface, slightly recurved. It projects above the upper jaw when
mouth closed. Second tooth much smaller, flattened and knifelike. Lateralmost tooth
smallest, with a small lateral cusp.
Colour pattern consisting of about seven broad dark bars on a lighter background,
three predorsal, one at dorsal base, two between dorsal and adipose and one at
adipose. A dark spot centred on lateral line just behind adipose. Adipose black
basally, translucent distally.
Distribution
At present recorded only from the upper Xingu River, Amazon River system (Fig. 8).
Knoppel (1972) reports a diet of sponges and detritus, with some plant remains and
larvae of ephemeropterans, trichopterans and chironomids.
a2
Genus Synaptolaemus Myers and Fernandez-Yepez, in Myers 1950
Synaptolaemus Myers and Fernandez-Yepez, in Myers 1950:190 (type by original
designation S$. cingulatus Myers and Fernandez-Yepez, in Myers).
Diagnosis
Synaptolaemus may be recognized from all other anostomines in having symphyseal
teeth of lower jaw about twice as long as wide (vs subequal or five times as long as
broad) and having gill membranes broadly united with isthmus. It shares with
Gnathodolus and Sartor (but differs from Pseudanos and Anostomus) a longer caudal
peduncle (x = 16-17 per cent SL vs 12-14 per cent), fewer vertebrae (x = 35 vs
36-41), a lower jaw that is longer than wide (vs as long as wide) and rounded or
conical dermal papillae on lower jaw. It differs from Gnathodolus and Sartor (and
shares with Pseudanos and Anostomus) a narrower body (x = 14 per cent SL vs
16-28 per cent) and a less deep preopercle (x = 51-64 per cent HL vs 70-75 per
cent) and snout (x = 33-41 per cent HL vs 45-51 per cent) and a smaller eye
(x = 21-24 per cent HL vs 26 per cent). It shares with Sartor (but not Pseudanos,
Anostomus or Gnathodolus) 12 circumpeduncular scales (vs 16).
Synaptolaemus cingulatus Myers and Fernandez-Yepez, in Myers, 1950
Fig. 29
Synaptolaemus cingulatus Myers and Fernandez- Yepez, in Myers 1950: 190 (original
description, type locality: upper Orinoco near bifurcation with Casiquiare,
Venezuela); Géry 1961 (aspects of cranial osteology); 1972/73 (description of upper
Xingu specimens, D’Arcy Thomson deformation coordinates); Knoppel 1972 (diet).
Diagnosis
As for genus.
Description
A fusiform, somewhat compressed species, with a size range of specimens examined
of 51-109 mm SL. The following measurements are expressed as percentages, and
these and the meristics consist of a mean, the range in parentheses, the standard
deviation and the standard error respectively.
As percentage of standard length: lower jaw to anal-fin origin 79.4 (77.7-82.0),
0.014, 0.005; lower jaw to adipose-fin origin 86.6 (84.3—-88.1), 0.013, 0.005; lower
jaw to dorsal-fin origin 50.7 (49.1—52.5) 0.011, 0.004; lower jaw to pelvic-fin origin
55.2 (51.7-58.4), 0.023, 0.008; dorsal-fin origin to caudal-fin origin 52.2
(50.5-53.9), 0.013, 0.005; dorsal-fin origin to adipose-fin origin 36.7 (34.8—38.3),
0.011, 0.004; peduncle length 16.8 (15.7-18.7), 0.009, 0.003; peduncle depth 10.9
(10.3-11.7) 0.006, 0.002; head length 28.5 (27.1—30.7), 0.012, 0.004; body depth
23.4 (20.8-27.2), 0.021, 0.007; body width 12.3 (9.7-14.6), 0.018, 0.006.
As percentage of head length: preopercle length 74.6 (72.3—76.7), 0.015, 0.005;
snout length 43.1 (38.2-47.7), 0.035, 0.013; head depth 68.3 (64.1—75.9), 0.035,
a3
0.012; preopercle depth 59.4 (57.0-63.4), 0.019, 0.007; snout depth 40.3
(37.6-44.0), 0.024, 0.009; eye diameter 22.4 (20.4-25.9), 0.018, 0.006; bony
interorbital 27.1 (23.8—-30.1), 0.022, 0.008.
Lateral-line scales 37.8 (37-39), dorsal transverse 3.5—4, ventral transverse 3-3.5,
predorsal 11.0 (10-12), dorsal to adipose 11.9 (11-13), adipose to caudal 7.6 (6—9),
isthmus to pelvis 15.9 (15-18), pelvis to anus 7.0 (6-8), anal to caudal 8.4 (7-10),
circumpeduncular 12. Scales (from below dorsal origin) with many radii and
considerable reticulations about focus (Fig. 7E). Lateral-line scales also with many
radii but seldom reticulations.
Dorsal fin iii 10, caudal fin with 10 upper and 9 lower principal rays, anal iii 8,
pelvic i 8 (once i 7, one side only), pectoral 1 12-1 18 (x = 15.8). Olfactory lamellae
increasing with body size, from 42 at 75 mm SL to 48 at 108.5 mm SL. Vertebrae
34-35 (x = 34.6) + ural centrum (with 13-14 (x = 13.5) caudal vertebrae, including
ural centrum. First pterygiophore of dorsal fin lies between neural spines of
tenth-eleventh or eleventh-twelfth vertebrae. Four branchiostegal rays.
Four orange-brown teeth in each half of each jaw. Medial two upper jaw teeth in
each jaw broadly rounded, with a somewhat irregular edge; third tooth tricuspid (with
medial cusp dominating lateral ones); lateralmost tooth truncate to slightly tricuspid.
In each half of lower jaw, symphyseal tooth spoonshaped (with a concave posterior
surface) and nearly twice the size of next tooth, which is tricuspid. Third tooth about
two-thirds size of second, and slightly tricuspid, while lateralmost tooth truncate, and
very small. Upper lip finely plicate. Lower lip has four—five irregular rows of conical
papillae, largest of which is about half length of exposed portion of upper jaw
symphyseal pair of teeth.
Colour pattern in alcohol a darkish yellow-brown with seven light bands encircling
body. Three are predorsal (third at dorsal origin), two postdorsal, one at adipose fin
and one posterior to it. In life, chocolate-brown with the light bands being bright
orange-red (F. Mago-Leccia, pers. comm.).
Distribution
S. cingulatus has been recorded from two localities in the Orinoco drainage system (at
the bifurcation with the Casiquiare River and from the lower Paragua River) and from
the upper Xingu River which drains into the Amazon near its mouth (Fig. 8).
Knoppel (1972) reported that two upper Xingu specimens of S. cingulatus had fed
extensively on ephemeropteran larvae.
Variation
The two specimens from the upper Xingu have a longer snout to pelvic fin origin (58
per cent SL vs 52-56 per cent), a greater body depth (26-27 per cent SL vs 21-24 per
cent) and a deeper head (70-76 per cent head length vs 64-68 per cent) than the
Orinoco population. More specimens would be needed to confirm these apparent
differences.
34
Osteology Section
Introduction
In the following section, I have described the osteology under a series of headings
encompassing convenient regions of the body. A detailed description of the bony
structures in each region follows, and is derived from cleared and stained material of
Pseudanos trimaculatus. Finally, differences from the condition described for
P. trimaculatus are documented for all other species of anostomines for which
material was available (see Appendix 2). This Variation section may consist of a
single paragraph discussing all the species examined, or, where the differences are
more extensive, a separate paragraph is accorded each species.
Osteological nomenclature basically follows that of Weitzman (1962) in his classic
study of Brycon. I have departed from this nomenclature in three cases, using
intercalar for his opisthotic, vomer for prevomer, and six hypurals plus a parhypural
as opposed to seven hypurals. In addition, I have added, in parentheses, the more
recent terminology for the bones of the lower jaw (Nelson, 1973), hyoid arch
(Nelson, 1969) and occipital region (Patterson, 1975).
Infraorbital Bones and Associated Elements
Pseudanos trimaculatus
Fig. 30
Infraorbital series of six bones. Infraorbital one an elongated oval with an irregular
margin, narrower posteriorly. Sensory canal bone-enclosed, in shape of an inverted
‘*y’’ along anterior margin of bone. Canal openings at three extremities of ‘‘y’’, a
fourth opening midway along shaft. Infraorbital two a more regular elongated oval
with a more regular margin, sensory canal along middle of bone. Canal openings at
extremities, and one roughly midway along its length. Posterior margin of infraorbital
two lateral to anterior tip of infraorbital three, which has a well developed lamina
ventrally. Sensory canal, open at both ends, along slightly concave dorsal margin.
There may be two additional lateral openings (one anteriorly, one posteriorly). Wall
of canal separating these pores from terminal openings may break down so that
Openings are confluent (as in figure). Infraorbital four with sensory canal passing
upwards along middle of the bone. Usually a separate posterior opening dorsally,
near terminal opening (not in specimen figured). Infraorbital five roughly triangular,
with sensory canal along anterior margin. Infraorbital six (dermosphenotic) becoming
broader posterodorsally with increasing body size. Sensory canal passing vertically
upwards, along dorsal edge, resulting in a small anterodorsal lamina and a large
posterior one. Dorsal portion of preopercular canal passes through posterior margin.
In some individuals this canal forms posterior margin of bone, in others (e.g. figured
specimen) there is a small lamina of bone posterodorsally.
Antorbital and supraorbital bones small and flat, former attached anteroventrally
by connective tissue to dorsal surface of infraorbital one. Nasal flat, bearing
Sy
bone-enclosed supraorbital sensory canal. Canal straight, open at both ends, and with
two lateral openings along its length.
Variation
The above description also applies to P. irinae. In A. plicatus, A. spiloclistron
(Fig. 31A), A. anostomus and A. ternetzi, bony canal of infraorbital one is I-shaped
with extended cross pieces (an ‘‘H’’ on its side). In P. gracilis and A. intermedius it
is in form of a “‘less than’’ sign, with only three openings (Fig. 31B), in
Synaptolaemus it is C-shaped (Fig. 32A) and in Gnathodolus it is Y-shaped with stem
pointing anteriorly (Fig. 32B). In Sartor, canal is as for A. plicatus, etc., but
posteroventral channel extends halfway along ventral margin of bone.
Infraorbital two has a better developed ventral lamina than in P. trimaculatus in
A. plicatus, A. spiloclistron (Fig. 31A), A. anostomus, A. ternetzi and Synap-
tolaemus (Fig. 32A, where anterior portion of canal curved). In A. intermedius it is
slightly curved anteriorly, and has an additional opening anteriorly. It is elongate in
Gnathodolus (Fig. 32B), similar to P. trimaculatus in P. gracilis (Fig. 31B), and has
an intermediate form between Gnathodolus and Synaptolaemus in Sartor. Infraorbital
three with no significant variation. In all but P. gracilis, infraorbital four has a broad
posterior lamina of bone (Figs. 31A, 32A, 32B).
Preopercular canal passes through posterior part of infraorbital six in A. spiloclis-
tron and A. ternetzi. In P. gracilis and A. intermedius this canal forms extreme
posterior margin of that bone, and it may be in this form or absent in A. anostomus.
No trace of canal in A. plicatus, Sartor, Synaptolaemus or Gnathodolus. In latter two
genera, infraorbital canal diverges to form two openings dorsally (Figs. 32A and
32B).
Suspensorium and Jaws
Pseudanos trimaculatus
Figs. 33, 34
Quadrate triangular, with condyle for articular anteriorly. A horizontal lateral shelf of
bone, which forms floor of adductor mandibulae chamber and which continues
posteriorly to end beneath anterior part of symplectic, along ventral surface of
quadrate. Dorsal tip of quadrate in contact with lateral surface of palatine, notch in
posterior face of quadrate. Maximum height of quadrate 35-40 per cent of its total
length. Ectopterygoid small, lying along anterodorsal face of quadrate; posterodorsal
process articulating with: small ovoid palatine. Palatine articulates anterodorsome-
dially with vomer and mesopterygoid posteromedially. Mesopterygoid a small bone
largely overlain laterally by metapterygoid. Metapterygoid large, upper part inclined
dorsomedially to form a sloping shelf under orbit. Symplectic in contact with
quadrate anteriorly, curving posterodorsally between ventral margin of the
metapterygoid and preopercle. Connected to hyomandibular posterodorsally by a
plug of cartilage, with interhyal articulating on medial surface of plug. Hyomandibu-
lar a vertical plate of bone lying medial to preopercle and with an anteroventral
process to metapterygoid.
36
Opercle with a somewhat convex lateral surface and a small rounded process
anterodorsally for insertion of dilatator operculi muscle. Subopercle curved, bluntly
rounded. Interopercle wide posteriorly, lying lateral to anterior tip of subopercle,
becoming attenuated anteriorly. Beneath anterior tip of preopercle interopercle gives
rise to a long ligament to posterior face of angular. Preopercle right-angled, with a
medial flange from anterior margin at angle, and lying lateral to rest of suspensorium
(except for posterior extension of quadrate). Preopercle canal with a total of six
openings (including terminal ones), continuing anteriorly in two small tubelike canal
bones.
Maxilla flattened, with ventromedial flange beneath the posterodorsal region of the
premaxilla. An anterodorsal flange covers posteroventrolateral face of premaxilla
and, below this, maxilla expands into a flat, somewhat triangular plate. A nerve
enters medial face of maxilla, and courses ventrally before exiting laterally.
Premaxilla, when viewed from an anterodorsal position, like a right-angled triangle; a
short, rounded medial flange (see Fig. 37, of A. plicatus) extends from ventral
midline to underlie symphyseal pair of teeth. Four replacement teeth lying free in
connective tissue in each jaw, underlying four functional teeth (which are attached by
connective tissue). Inner three replacement teeth tricuspid, lateralmost with four to
five cusps.
Articular (angulo-articular) small, forming posterior margin of lower jaw. Angular
(retroarticular) very small, joined to posteroventrolateral face of jaw; coronomecke-
lian a small, flat, rounded bone on medial face of dentary. Dentary forming major
part of lower jaw. Tooth cavity bridged medially by a thin lamina of bone (cavity thus
formed being open at both ends). Replacement teeth lying free in cavity below
functional teeth, with inner pair bicuspid, third tricuspid and lateralmost with four to
five cusps. Inner pair of teeth (both functional and replacement) with a distinct notch
across the anterior surface below cusps.
VARIATION
P. irinae. As for P. trimaculatus.
P. gracilis (Fig. 35). Palatine separated from quadrate by ectopterygoid. A
concavity in anteroventral margin of metapterygoid; quadrate height 32 per cent its
total length; otherwise as for P. trimaculatus.
A. plicatus (Figs. 36 and 37). Quadrate not as high as in P. trimaculatus (height
25--30 per cent length), lateral shelf poorly developed anteriorly. Notch in posterior
face of quadrate absent; ectopterygoid (which has a very small dorsal process)
separates quadrate from palatine. Sloping shelf of metapterygoid nearly horizontal.
Symplectic with well-developed laminae of bone at angle, lying lateral to
metapterygoid and preopercle. Posterodorsal margin of opercle somewhat concave.
Ventral triangular portion of maxilla broadly expanded (see Fig. 38 of A. spiloclis-
tron). Symphyseal replacement tooth of lower jaw, like functional one, without
cusps, and with concave (almost spoon-shaped) posterior margin. Tooth next to it is
similar, but two lateral replacement teeth have three to four cusps.
A. spiloclistron (Fig. 38). Quadrate less high than in A. plicatus (depth about 20
per cent of length). Metapterygoid longer than in A. plicatus; symplectic with small
dorsal and well developed ventral bony laminae. Opercle with distinct concavity in
posterodorsal surface. Symphyseal lower jaw replacement tooth without cusps, next
oY
tooth bicuspid. Otherwise this species differs from P. trimaculatus as A. plicatus
does.
A. intermedius. Quadrate narrow (depth about 21 per cent of length). Symphyseal
replacement tooth of lower jaw bicuspid. Otherwise this species differs from
P. trimaculatus in the same way that A. plicatus does.
A. anostomus. Quadrate depth about 28 per cent of its length, no notch in posterior
edge, lateral shelf poorly developed anteriorly, quadrate separated from palatine by
ectopterygoid. Metapterygoid shelf sloping. Posterodorsal margin of opercle
concave. Ventral part of maxilla somewhat more developed than in P. trimaculatus.
A. ternetzi. Quadrate depth 25-28 per cent of its length. Ventral margin of maxilla
better developed than in A. anostomus, with a notch in its posterior edge. Other
differences from P. trimaculatus as for A. anostomus.
Synaptolaemus (Figs. 39 and 40). Quadrate height about 32 per cent of its length,
quadrate separated from palatine by ectopterygoid (which has no posterodorsal
process), a small notch present on posterior quadrate surface, lateral shelf from below
palatine. Metapterygoid shelf sloping. Symplectic long, thin and gently curved,
overlain posterodorsally by median shelf of preopercle. Opercle concave posterodor-
sally. Maxilla greatly expanded ventrally, nerve foramen passing straight through
bone (not in a vertical channel). Premaxilla small, medial two replacement teeth
without cusps, lanceolate, outer two teeth tricuspid. Lower jaw symphyseal
replacement tooth without cusps, second and third tricuspid, outer without cusps.
Gnathodolus sp. (Fig. 41). Quadrate very long and thin (height 7-8 per cent
length), posterior extension of lateral shelf extending to angle of preopercle, shelf
beginning about midway along length of quadrate, no notch on posterior face, not in
contact with palatine. Ectopterygoid long and thin, free anteriorly, no dorsal process.
Palatine oblong, reaching ectopterygoid ventrally, but covered ventrolaterally by a
somewhat rectangular mesopterygoid; both these bones have articular surfaces for
vomer (they articulate with vomer posteroventral to lateral ethmoid). Metapterygoid
shelf nearly horizontal. Preopercle ends anteriorly beneath middle of symplectic.
Hyomandibular with a long, thin anteroventral process to metapterygoid. Dentary
very long and narrow, only symphyseal tooth (for which two replacement teeth, one
above the other, are present). Maxilla broad, foramen passing vertically through
bone.
Sartor. Quadrate height 34.5 per cent of its length, separated from palatine by
ectopterygoid (which has no posterodorsal process), no notch in posterior face of
quadrate, lateral shelf from below palatine. Metapterygoid shelf horizontal, with a
lateral extension of this shelf as well, lying dorsal to lateral shelf of quadrate.
Symplectic long, thin and gently curved, overlain posterodorsally by a median
process from preopercle. Opercle margin concave posterodorsally. Premaxilla small,
all replacement teeth tricuspid. Foramen vertically through maxilla, which has an
expanded base. Dentary elongate (but not as much as in Gnathodolus). Symphyseal
replacement tooth without cusps, lateral two teeth bicuspid.
38
Hyoid Arch
Pseudanos trimaculatus
Figs. 42—44, 45B
Ventral hypohyal (ventrohyal) forming anterolateral margin of hyoid arch, with a
notch in ventral surface. Dorsal hypohyal (dorsohyal) small, rounded, situated on
dorsomedial surface of arch. Ceratohyal (anterohyal) large, more or less square, with
a posteroventral extension. Epihyal (posterohyal) semicircular, with an anterodor-
solateral foramen, joint with ceratohyal almost vertical. Interhyal small, rodlike,
articulating ventrally with posterodorsolateral surface of epihyal and dorsally with
medial face of cartilaginous plug separating hyomandibular and symplectic. Three
spathiform branchiostegal rays; first articulating with ventral face of ceratohyal just in
front of posteroventral extension, second on lateral face of this extension and third
with ventrolateral face of epihyal. This latter ray has a dorsal process proximally,
which is rounded in small individuals but develops into a posteriorly pointed hook in
larger specimens (cf. Figs. 42 and 43). First branchiostegal ray articulates with
ceratohyal by a pair of articular processes. In one Ecuadorian specimen, left lateral
articulation is double, and a ridge of bone passes from point where these two lateral
articulations meet along length of ray. This may indicate loss of first ray by fusion
rather than reduction. Urohyal V-shaped (Fig. 44), with dorsal edge longer than
ventral edge, its posterior margin variously scalloped. Basihyal rodlike, cartilaginous
anteriorly. A (toothless) basihyal toothplate overlies cartilage and anterior portion of
basihyal itself (Fig. 45B).
VARIATION
The above description applies to P. irinae, P. gracilis and A. ternetzi (but
epihyal-ceratohyal joint oblique in latter). In A. plicatus, A. intermedius and
A. spiloclistron (Fig. 46A), joint between epi- and ceratohyal is at about 45° to
vertical. There are four branchiostegal rays, and urohyal is deeper and less V-shaped
(Fig. 46B). A. anostomus (also A. brevior) has four branchiostegal rays, although in
some individuals first ray may be considerably reduced. Epihyal-ceratohyal joint is
oblique. Synaptolaemus (Fig. 47) with four branchiostegals; a small process on first,
an anterodorsal process on second, but none on third or fourth. Foramen on dorsal
surface of epihyal. Epihyal-ceratohyal joint at 35° to vertical. Urohyal with a long
dorsal and much shorter ventral limb, posterior surface concave. Gnathodolus with
four branchiostegal rays (first small), no processes. Foramen on lateral face of
ceratohyal, with a long deep groove extending posteriorly onto the epihyal. Joint
between epihyal and ceratohyal almost vertical. Urohyal as for Synaptolaemus.
Sartor with four branchiostegal rays; a rounded process on proximal dorsal face of
fourth. Foramen dorsolaterally on epihyal. Epihyal-ceratohyal joint somewhat
oblique, urohyal as for Synaptolaemus. Basihyal toothplate with a posteriorly
directed ventral hook.
39
Branchial Arches
Pseudanos trimaculatus
Figs. 45B, 48, 49
Basibranchials one to three present (although first not ossified in two smallest
specimens), and interconnected by cartilage (Fig. 45B). Dorsally, basibranchials two
and three overlain and fused to laminae of bone, which may represent toothplates.
Three squarish hypobranchials, third with slightly notched surface surrounding
posterior part of basibranchial three. First three ceratobranchials articulate with
posterolateral margins of three hypobranchials, fourth articulates with lateral margin
of median cartilaginous plug and fifth articulates with posterior face of plug.
Posteromedial margin of fifth ceratobranchial expanded as a flat horizontal plate with
two to three uneven rows of teeth on dorsal surface (rows passing from anteromedial
to posterolateral). Seven to 10 teeth in first row, 4 to 7 in second and 0 to 4 in third.
Each tooth with cusp on anterior surface proximal to tip; teeth replaced from anterior.
Four epibranchials articulate with first four ceratobranchials, Y-shaped proximally
(Fig. 49). Four infrapharyngobranchials, first (suspensory) rod shaped, second
articulating with epibranchials one and two, third with epibranchials two and three.
Fourth represented by rod of cartilage between medial face of epibranchial four and
posterior face of infrapharyngobranchial three. Toothless fourth pharyngobranchial
toothplate adheres to ventrolateral face of this rod of cartilage, and contacts
anteromedial face of epibranchial four posteriorly. Fifth pharyngobranchial toothplate
is attached to ventromedial face of fourth epibranchial; it bears two rows of teeth,
cusped similarly to those on ceratobranchial five. However, here cusps face
posteriorly, and teeth posteriorly replaced. Three to four teeth in anterior row and
seven to eight in posterior row.
VARIATION
Both specimens of P. irinae lack basibranchial one (Fig. 45A). All species of
Anostomus, and P. irinae, with better developed lamina on ceratobranchial five and
more teeth (12-14 first row, 10-11 second row, O-1 third row) except for
A. intermedius which has 10-11 in first row, 4—5 in second, third row absent; more
teeth on pharyngobranchial five tooth plate (4 to 8 first row, 10-12 second row) again
with exception of A. intermedius with | tooth in first row and 7 to 8 in second.
Synaptolaemus (Fig. 50) with well-developed first basibranchial, third basibranchial
arched (in lateral view). Ceratobranchial five with 10 teeth in first row, then 8 to 9,
and | in third row. Pharyngobranchial toothplate with 5 to 6 in first row, 10 in
second. Gnathodolus with fewer teeth than other anostomines, six in first row, four in
second on fifth ceratobranchial and three in first row, five in second on
pharyngobranchial toothplate. Sartor with 13 teeth in first row of ceratobranchial
five, 12 in second and 0-1 in third. Basibranchial one well developed, basibranchial
series as a whole somewhat dorsoventrally flattened, third basibranchial slightly
arched. Pharyngobranchial five with 7 teeth in anterior row and 12 in posterior row.
40
Cranium
Pseudanos trimaculatus
Figs. 51-55
Width of skull 53-57 per cent length, depth 42-46 per cent length. Ethmoid
(Figs. 51-53) triangular in dorsal view, overlain by frontals posteriorly, meeting
lateral ethmoids laterally and joined by cartilage to vomer ventrally. No lateral wings,
bone as long as wide (width measured transversely at anterior margin of cranial
fontanel, length from anterior tip to fontanel).
Vomer (Figs. 51, 52) toothless, bulbous anteriorly, becoming a laterally flattened
shaft of bone sutured to parasphenoid posteriorly. Posterior to joint with ethmoid a
pair of cuplike projections arise from dorsal surface to vomer, their medial edges
meet in midline forming median septum. Vomer joined posterodorsally to lateral
ethmoids.
Lateral ethmoid (paired) forming anterior wall of orbit (Figs. 51-53). Overlain
dorsally by frontal, contacting orbitosphenoid dorsally and ventrally; these two bones
enclose olfactory nerve foramen. Ventromedially lateral ethmoid joins parasphenoid
(posteriorly) and vomer (anteriorly); anterodorsomedial surface contacts ethmoid.
Lateral ethmoid forms posterior wall of nasal cavity. Distinct notch present in
ventromedial margin for passage of olfactory nerve in small specimens; notch
surrounded by thin wall of bone medially in larger individuals.
Frontal (paired) large, roofing orbit (Figs. 51, 53); contacting ethmoid anteriorly,
parietal posteriorly, and lateral ethmoid, orbitosphenoid, pterosphenoid, sphenotic
and pterotic ventrally. Epiphyseal bars from each side meet and interdigitate in
midline, as do frontals themselves in larger individuals, where a small cranial
fontanel is present anteriorly. In smaller specimens anterior part of cranial fontanel
open posteriorly to epiphyseal bar but in smallest specimen (43.3 mm SL, Ecuador)
open for its entire length.
Parietal (paired) lying posterior to frontal, which covers it anteriorly (Figs. 51, 53);
overlying pterotic laterally and epiotic and supraoccipital posteriorly. Parietals
medially separated by posterior part of cranial fontanel; in large specimens, two
parietals may just meet in midline anteriorly. Supraorbital and supratemporal canal
systems pass through parietal.
Supraoccipital overlain by parietals anteriorly, laterally joined synchondrally to
epiotic and exoccipital (Figs. 51, 53). Supraoccipital crest, and hence sulcus, short.
Exoccipital (paired) forming posteroventral face of skull (Figs. 51-54); joining
other exoccipital dorsally, supraoccipital and epiotic dorsolaterally, pterotic,
intercalar and prootic laterally and basioccipital ventrally. Usually a single foramen
lying lateral to lagenar capsule for glossopharyngeal and vagus (IXth and Xth) cranial
nerves (although one or more small foramena may. be present anteriorly). Large
lateral occipital foramen dorsal to lagener capsule and lateral to foramen magnum.
Floor of foramen magnum formed by a thin horizontal median lamina of exoccipital
which meets a similar lamina from other exoccipital in midline; cavity formed
beneath these laminae, cavum sinus imparis, in shape of a flattened ellipse.
Posttemporal fossa (Figs. 51, 53, 54) an extensive chamber on posterior face of
skull, divided into dorsal and ventral portions by anterolateral arm of epiotic.
41
Intercalar (Fig. 52) roughly T-shaped (with posteromedial arm of ‘‘T’’ poorly
developed). Head of **T’’ covers joint between pterotic and exoccipital and shaft
covers junction of prootic, pterotic and exoccipital.
Basioccipital a long, narrow bone, joined to prootic anteriorly, exoccipital dorsally
and parasphenoid ventrally (Figs. 51, 52, 54). Posteriorly it forms condyle for
articulation of first vertebra. Baudelots ligament arises from basioccipital ventral to
lagenar capsule.
Epiotic (or epioccipital; paired) contacts supraoccipital and exoccipital ventrally
and medially, and pterotic ventrolaterally (Figs. 51, 53, 54). Dorsolateral face gives
rise to anterior process which joins posterior face of parietal and medial process of
pterotic, forming strut across posttemporal fossa.
Pterotic (paired) partly overlain dorsomedially by frontal and parietal (Figs. 51—
54); contacting sphenotic anteriorly, prootic ventrally and exoccipital, intercalar and
epiotic posteriorly. Well-developed ventrolateral spine-like process; no evidence of
temporal foramen. Anteroventrally, pterotic has a concave depression for reception of
posterior head of hyomandibular.
Sphenotic (paired) forms posterodorsal margin of orbit; covered anteriorly and
medially by frontal and pterosphenoid, posteriorly by pterotic (Figs. 51-53). Behind
orbit, indentation combines with frontal to form dilator fossa (overlain laterally by
dermosphenotic).
Prootic (paired) large, forming major component of floor and sides of braincase
(Figs. 51, 52). Contacts sphenotic, pterotic and intercalar dorsally, exoccipital and
basioccipital posteriorly, parasphenoid ventrally and pterosphenoid anterodorsally.
Ventromedial shelf of bone forms roof of myodome. Region of prootic-sphenotic
junction concave, forming anterior part of hyomandibular fossa.
Subtemporal fossa (Fig. 52) a shallow depression mainly in pterotic, but includes
posterodorsal region of prootic and rimmed posterolaterally by intercalar.
Pterosphenoid (paired) forming posterodorsal wall of orbit, partly overlain by
frontals dorsally (Figs. 51, 52); contacting sphenotic posteriorly, prootic posterovent-
rally and orbitosphenoid anteriorly. It does not meet other pterosphenoid in ventral
midline.
Orbitosphenoid (Figs. 51, 52) a more or less butterfly-shaped bone (in ventral
view), joining pterosphenoid posteriorly, frontal dorsally and lateral ethmoid both
dorsolaterally and anteroventromedially.
Parasphenoid a long thin bone sutured to vomer anteriorly, and joined to ventral
surface of lateral ethmoid dorsally (Figs. 51, 52). A dorsolateral wing at rear of orbit
is sutured to prootic but joined by cartilage behind this. Dorsal surface of posterior
part of parasphenoid joined to basioccipital, a pair of flattened processes not attached
to basioccipital extend posteriorly. Small ventral median keel present. Foramen
present in shaft of parasphenoid below orbitosphenoid in three specimens from Mato
Grosso (Fig. 55), but absent in two Ecuadorian individuals.
VARIATION
P. irinae. Width of skull 52 per cent length, depth 41-43 per cent. Foramen for
olfactory nerve in lateral ethmoid completely surrounded by bone medially. Head of
intercalar wider and better developed than in P. trimaculatus.
P. gracilis. Width of skull 55 per cent length, depth 39 per cent. Cranial fontanel
42
open for whole length, lateral head of intercalar well developed. Otherwise as for
P. trimaculatus.
A. plicatus. Width of skull 52 per cent length, depth 38 per cent. Ethmoid a narrow
V, its width 65 per cent of its length. Anterior tip of ethmoid hooked in lateral view.
Anterior lamina of lateral ethmoid poorly developed (see Fig. 38 of A. spiloclistron),
with a notch in its anterior margin. Foramen for olfactory nerve not walled by bone
medially. Cranial fontanel entirely open. Posterior face of supraoccipital with a
median ridge with a shallow groove down centre for reception of anterior face of
neural complex. Sulcus wide, forming a shallow trough. Ridge of exoccipital runs
from just behind the vagus foramen to head of intercalar. Joint between pterosphenoid
and orbitosphenoid aligned laterally (not inclined anterolaterally). Parasphenoid keel
beneath orbit well developed.
A. spiloclistron (Fig. 38). Width of skull 44 per cent length, depth 36 per cent.
Cranial fontanel closed behind epiphyseal bar. Ridge behind vagus foramen present,
but less well developed than in A. plicatus. Other differences from P. trimaculatus as
for A. plicatus.
A. intermedius. Width of skull 44 per cent length, depth 37 per cent. Olfactory
nerve foramen with a well-developed median wall of bone. Otherwise this species
differs from P. trimaculatus in the same way that A. plicatus does.
A. anostomus (Fig. 56). Width of skull 50 per cent length, depth 33-34 percent.
Ethmoid width 55-65 per cent length. Lateral ethmoid with notch in margin of poorly
developed anterior lamina, olfactory foramen narrowly surrounded by bone medially.
Cranial fontanel open posteriorly only to epiphyseal bar. Parietals fully joined in
midline for their entire length. Supraoccipital tip exposed posterodorsally, posterior
surface grooved as in A. plicatus, sulcus a shallow trough. Lateral exoccipital
foramen well developed, ridge to intercalar posterior to vagus foramen present.
Epiotic expanded dorsally, with a wide, flaring anterior process resulting in a very
small dorsal chamber of posttemporal fossa. Epiotic with well-developed posterior
process, posterior process of pterotic slender. Median ventral keel present on
orbitosphenoid. Dorsal flange on parasphenoid ventral to anterior half of orbit,
parasphenoid narrows ventral to prootic and basioccipital. No pair of free posterior
processes.
A. ternetzi. Width of skull 45-50 per cent length, depth 32-35 per cent. Ethmoid a
narrow V (its width 64-65 per cent of its length). Foramen for olfactory nerve open
medially in two smaller specimens, but enclosed by narrow median strut of bone in
largest specimens. Cranial fontanel entirely open in smaller specimen, but closed in
larger example. Dorsal chamber of posttemporal fossa small (but not as reduced in
A. anostomus) and posterior process of epiotic also less well developed. Other
differences from P. trimaculatus are as described for A. anostomus.
Synaptolaemus (Fig. 57). Width of skull 45 per cent length, depth 36 per cent.
Ethmoid a very narrow V (width 53 per cent length), small pair of lateral projections
may be homologous with lateral ethmoid wings of Brycon (Weitzman, 1962). Lateral
ethmoid with no anterior lamina and little indication of a notch, olfactory foramen
open medially. Cranial fontanel entirely open, epiphyseal bar wide. Parietal sutured
to supraoccipital at edges of posterior margin of fontanel. Supraoccipital crest a
narrow V, sulcus rounded, posterior profile (in lateral view) rounded, posterior face
grooved. Well-developed ridge present on exoccipital between vagus foramen and
intercalar. Lateral exoccipital foramen well developed, cavum sinus imparis
43
rectangular. Dorsal chamber of posttemporal fossa much reduced, filled by
dorsomedial expansion of epiotic. Posterior process of pterotic thin. Subtemporal
fossa relatively well developed, primarily in pterotic. Pterosphenoid-orbitosphenoid
joint almost vertical. Orbitosphenoid with very well-developed ventral flange, which
joins process from dorsal surface of extremely well-developed dorsal flange of
parasphenoid. Foramen present in parasphenoid near rear of orbit. Parasphenoid
narrow beneath prootic, but widening somewhat posteriorly. Very well-developed
pair of processes extending posteriorly below basioccipital condyle.
Gnathodolus sp. (Fig. 58). Width of skull 50 per cent length, depth 42 per cent.
Ethmoid narrow (width 61 per cent length), no anterior lamina, notch present in
anterior surface, olfactory foramen bounded by bone medially. Vomer very well
developed, with short dorsolateral process to lateral ethmoid, and large, horizontal
flange of bone extending a third of the way across orbit posteriorly, ventrolateral
groove in posterior half of flange for articular facets of palatine and mesopterygoid.
Anterior edge of palatine in line with ventrolateral process of lateral ethmoid. Cranial
fontanel open. Groove in posterior face of supraoccipital and sulcus in form of
shallow trough. Ridge of exoccipital from vagal foramen to intercalar well
developed. Lateral occipital foramen well developed. Epiotic with narrow
anterolateral process to pterotic and parietal. Dorsal chamber of posttemporal fossa
large. Subtemporal fossa well-developed, no posterior process on epiotic. Joint
between pterosphenoid and orbitosphenoid almost vertical. Orbitosphenoid with
sharp ventral process not reaching parasphenoid. Parasphenoid with a well-developed
ventral keel ending abruptly posterior to orbit; joint with vomer oblique; posterior
process short.
Sartor (Fig. 59). Width of skull 59 per cent length, depth 44 per cent. Ethmoid
V-shaped, its width 82 per cent of its length. Lateral ethmoid with no anterior lamina,
notch on anterior face, olfactory foramen open medially. Medial keel of vomer very
deep at joint with parasphenoid (similar in this respect to Gnathodolus). Cranial
fontanel open. Sulcus wide and troughlike, posterior face of supraoccipital grooved.
Ridge behind vagus well developed. Intercalar small. Dorsal chamber of
posttemporal fossa well developed. No process on posterior face of epiotic.
Pterosphenoid-orbitosphenoid joint oblique, orbitosphenoid with ventral flange
pierced by foramina, not in contact with parasphenoid. Ventral flange of
parasphenoid well developed anteriorly.
Weberian Apparatus
Pseudanos trimaculatus
Figs. 51, 52
First centrum simple disc of bone with pair of deep, narrow pits, one on either side of
dorsal midline, which receive ventral peglike articular processes of scaphia. Second
vertebra with pair of lateral processes from ventrolateral margins of centrum, the
processes extend anterolaterally to anterior margin of first centrum, extending
laterally until in line with (or slightly beyond) lateral margin of tripus. Neural arch
pedicle of third vertebra fused to transverse process of that vertebra, transverse
44
process fused to anterolateral face of centrum. Dorsal and posterodorsal surfaces of
neural arch pedicle contact ventral surface of neural arch complex and anteroventral
surface of neural arch of fourth vertebra respectively. Pleural rib of fourth vertebra
arising from a deep socket in lateral face of fourth centrum, socket roofed by a flange
of bone dorsally. Rib extending laterally, lying dorsal to transformator process of
tripus. Os suspensorium arising from ventral surface of rib and curving
ventromedially to beneath third centrum. Os suspensioria connected together by
connective tissue.
Claustrum small, curved, rodlike, passing from midline just below anteroventral
tip of neural complex to posterodorsal surface of scaphium. Scaphium cup-shaped,
with posterodorsal process. Peglike ventral process articulating in socket of first
centrum. Scaphium joined by ligament to intercalarium. Intercalarium flat, vertical
plate of bone articulating proximally between transverse process (laterally) and neural
pedicle (medially) of vertebra three. Tripus complex, but basically triangular;
attached anteriorly via ligament to posterolateral face of intercalarium. Triangular
body of tripus a flat, horizontal lamina of bone, with raised dorsal ridges along two
proximal edges. Anterior of these ridges split vertically from proximal apex of
triangle for much of length of mdge. More medial of double ridges so formed
continues medially, firmly bound into deep socket in vertebra three, and forming a
leaf-springlike suspension for tripus. Posterolateral margin of tripus gives rise to thin
transformator process which curves posteromedially (ventral to pleural rib of vertebra
four) to end just posterior to ventral tip of os suspensorium (being connected to latter
by a fan-shaped ligament). Neural complex a broad flat lamina of bone attached to
posterior face of cranium anteroventrally and to dorsal faces of neural pedicle and
neural spine of third and fourth vertebra ventrally.
VARIATION
The description above also applies to P. irinae and P. gracilis. In A. plicatus,
A. spiloclistron and A. intermedius transverse process of vertebra three with a
foramen, anterior process of os suspensorium well developed, neural complex narrow
dorsally, and ‘‘leaf-spring’’ suspension of tripus less well developed. A. anostomus
and A. ternetzi with better-developed transverse process on vertebra two and narrow
neural complex; in latter species, pleural rib of vertebra four expanded dorsally and
anteriorly, overlying posterior region of tripus. In Synaptolaemus (Fig. 60) transverse
process of vertebra two curving posterodorsally, and that of vertebra three passing out
laterally (as opposed to anterolaterally). Neural pedicle of vertebra three less well
developed. Pleural rib of vertebra four with anterodorsal flange overlying tripus, and
lateral process curving anterolaterally. This latter condition also found in Sartor, but
not in Gnathodolus. In all three genera dorsal part of neural complex narrow.
45
Pectoral Girdle
Pseudanos trimaculatus
Figs. 61, 62
Extrascapular a small flat bone connected to anterolateral face of posttemporal and
bearing semicircular sensory canal on its medial face, posterior surface of which
gives rise to two other canals. Posttemporal a thin lamina of bone with a short medial
process near its ventral margin with sensory canal passing horizontally across it just
beneath medial process. Large foramen in middle of this canal giving rise to
posteroventrally directed canal passing through dorsal tip of supracleithrum.
Supracleithrum with shallow fork dorsally. A canal running ventrally in supraclei-
thrum to exit laterally near medial margin of that bone. Three postcleithra; dorsalmost
small, ovoid, closely applied to posteroventromedial margin of supracleithrum;
postcleithrum two a long flat lamina of bone attached to posteromedial face of
cleithrum; postcleithrum three (ventralmost) rodlike, attached to anteroventromedial
margin of postcleithrum two.
Cleithrum large, attached to mesocoracoid medially, scapula dorsomedially, and
coracoid at two points anteroventromedially. Cleithrum with long, tapering dorsal
process and broad, triangular posterior lamina just above fin rays. Mesocoracoid a
vertical strut between coracoid (dorsally) and V-shaped joint with scapula
(posteriorly) and coracoid (anteriorly); at dorsal end a thin strut of bone passing
posterolaterally along medial face of cleithrum. Coracoid joined to cleithrum in two
places anteroventrally, to mesocoracoid dorsally and scapula posterodorsally;
supporting ventralmost proximal radial (IV) posteriorly. Scapula somewhat curved
bridge of bone between cleithrum (dorsally), mesocoracoid (anteroventrally) and
coracoid (ventrally), supporting three dorsal proximal radials posteriorly (dorsalmost
of which (J) largest). Eight distal radials, dorsalmost three supported by dorsalmost
proximal radial (1).
VARIATION
P. irinae and P. gracilis have posteroventral margin of sensory canal in supraclei-
thrum Y-shaped, with two openings. This applies to all other anostomines except
Synaptolaemus, Gnathodolus and some individuals of A. ternetzi, where single. In all
these other species, joint between mesocoracoid and scapula and coracoid is
/ -shaped rather than V-shaped. Postcleithrum one reduced in A. spiloclistron,
absent on one side but present on other in single specimen of A. intermedius,
separated from postcleithrum 2 and reduced in Gnathodolus, and absent in
Synaptolaemus and Sartor. In Synaptolaemus ten distal radials and four proximal
radials in close contact with one another. Six distal radials present in Gnathodolus,
eight in Sartor.
46
Pelvic Girdle
Pseudanos trimaculatus
Figs. 63, 64
Pelvic bone (paired) a long, narrow sheet of bone, tapering to point anteriorly. Medial
process on the dorsal surface sutured to process from opposite side in midline. Ischial
process arises from posteroventral surface, passing posteriorly and then posterodor-
sally. Ridge present on ventral face of pelvis which forms large, lateral articular
surface for radials and lateralmost fin rays. Four radial elements, lateral two paired,
third and fourth single. Third small, lying at posterodorsolateral margin of fourth.
Fourth very well developed consisting of globular base with a flat, posterior process
lying medial to dorsal half of innermost fin ray. It is possible (and even probable) that
the large fourth radial represents the dorsal half of the small third radial, thus there
would be three paired radials in each pelvic fin.
VARIATION
In P. irinae, Synaptolaemus and Sartor, pelvic bones tend to be joined rather than
sutured in midline (Gnathodolus not examined).
Dorsal and Anal Fins
Pseudanos trimaculatus
Figs. 65, 66
Eleven proximal pterygiophores in dorsal fin (Fig. 65), vertical plates of bone with
thin laminae on anterior and posterior edges. Medial pterygiophores lie posterodorsal
to third to last proximal pterygiophores. Eleven distal pterygiophores (paired)
present. Anteriormost 3 (unbranched) fin rays articulate with first proximal and distal
pterygiophores, other 10 fin rays articulate each with its own distal pterygiophore.
Posteriormost fin ray is split through its base. Posterior to last proximal pterygiophore
a flat rounded piece of bone, the end piece or stay of Weitzman (1962).
VARIATION
In P. irinae dorsal stay absent. First four proximal pterygiophores of A. plicatus and
Synaptolaemus lack medial pterygiophores; A. spiloclistron, A. intermedius and
P. gracilis lack first three, Sartor lacks first two, A. anostomus lacks first four to five
and A. ternetzi lacks first three to six.
In anal fin, nine proximal pterygiophores similar in shape to those of dorsal fin
(Fig. 66). Medial pterygiophores present posteroventral to third through ninth
proximal pterygiophores. Nine distal pterygiophores (paired) present, first proximal
and distal pterygiophores support first three (unbranched) fin rays. Posteriormost ray
split through its base: anal stay present. In large specimens, third proximal and medial
pterygiophores may be fused. Small paired nubbin of bone (=unbranched ray?) may
be present in front of first unbranched ray (Fig. 66).
47
The above applies to P. gracilis, P. irinae, A. spiloclistron, A. intermedius and
Synaptolaemus. A. plicatus has medial pterygiophores present from fifth proximal
pterygiophore, A. anostomus from fourth to fifth, A. ternetzi from second to fifth and
Sartor from second. P. irinae, P. gracilis, A. anostomus and A. ternetzi usually
have small paired nubbins of bone anterior to first unbranched fin ray.
Caudal Skeleton
Pseudanos trimaculatus
Fig. 67
Four upper and two lower hypurals. Upper hypurals fit against posteroventral surface
of urostyle. Dorsalmost of lower hypurals fused anteriorly to compound ural centrum,
lowermost well removed from centrum. Parhypural fused to ventral surface of ural
centrum. Two pairs of uroneurals, anterior pair being much larger, lying parallel to,
and on either side of urostyle. Well-developed anterior flange (or modified neural
process) present on anterodorsal face of urostyle, notched dorsally for reception of
three epurals (of which second largest). Tip of neural spine of second preural centrum
(pu 2) supports dorsal procurrent rays and tips of haemal spines of pu 2 and pu 3
support ventral procurrent rays. Modified neural process bifid in one specimen from
Ecuador.
VARIATION
Above description applies to P. irinae, P. gracilis and A. ternetzi (in one specimen
of latter, neural spine of pu 2 is half normal size). In A. plicatus, A. spiloclistron,
and A. intermedius a foramen present in lowermost hypural, uroneural 1 wider and
better developed, and a large anterior lamina present on neural spine of pu 2. In
A. anostomus, uroneural 2 absent (present on one side of one specimen as a single
minute nubbin of bone).
DISCUSSION
Interpretation of the osteological data (as well as dermal papillae and colour pattern)
is based on the belief that Hennig’s (1966) method of phylogenetic reconstruction is,
at the present time, the most logical and consistent (and thus most useful). The
approach to the analysis of information is similar to that adopted in an earlier paper
(Winterbottom 1974b). In attempting to elucidate the phylogenetic relationships
within the Anostominae, I have examined three other genera of anostomid characoids
(Abramites, Leporinus and Schizodon), and have utilized the osteological studies of
Roberts (1969, 1974) and Weitzman (1962, 1964) on other groups of characoids in
my efforts to establish character states and trends. All osteological characters which
exhibited variation in the Anostominae were subjected to analysis. In some cases, I
could not obtain any interpretable results, usually because I was unable to find any
basis for decisions on whether a given character confidition was primitive or derived. A
selection of these cases is discussed below. However, comparison of the various
conditions of a character found in the anostomines with the condition of that character
in other anostomids, as well as other characoids, frequently allowed parsimonious
48
interpretations as to the direction of the transformation series (i.e. relative
apomorphy/plesiomorphy of each condition) of that character.
The data are analysed under the same anatomical headings as used in the
descriptive section.
Infraorbital Bones
INFRAORBITAL 1
In many generalized characoids, the sensory canal of this bone is straight and has
three openings, the terminal ones, and one at its midlength. I find it extremely
difficult to hypothesize the primitive arrangement of this canal in the anostomids, but
it would appear to have been a single tube, possibly curved, with a total of four
openings (as in Abramites and Schizodon). Variation in canal pattern in anostomines
is considerable, and I find it impossible to erect any one hypothesis that appears to be
more plausible than any other hypothesis. This also applies to the other infraorbitals,
but the condition of the sixth infraorbital (or dermosphenotic) warrants some
consideration (see below).
INFRAORBITAL 6
Usually this bone carries the infraorbital canal, which branches into two canals
dorsally. This condition is met in, for example, Brycon (a characid; Weitzman,
1962), Leporinus, Schizodon, Gnathodolus and Synaptolaemus. In other anos-
tomines, and in Abramites, the dermosphenotic is broadly developed posteriorly
(rather like the condition figured for Hepsetus and Hoplias by Roberts, 1969). In
Hepsetus, Hoplias and Abramites the canal is branched dorsally. This is not the case
in Sartor, Anostomus and Pseudanos; the canal is not branched dorsally. In the latter
two genera, and in Abramites (but with the exceptions of Anostomus plicatus and
some specimens of A. anostomus), the dorsal portion of the preopercular sensory
canal passes vertically across the posterior border of the dermosphenotic. Once again
it is difficult to arrive at any plausible hypothesis of relationship without a priori
assumptions. If two canals passing through the dermosphenotic is an advanced
condition, Abramites is more closely related to the genera Pseudanos and Anostomus
(with, presumably, the exception of A. plicatus and some specimens of A. anos-
tomus) than either is to Gnathodolus, Sartor or Synaptolaemus. Alternatively, if an
unbranched infraorbital canal is advanced, then Sartor, Pseudanos and Anostomus
are sister groups, and the presence of the preopercular canal in the dermosphenotic is
due to convergence. It seems reasonable to assume that the ancestor of A. plicatus
possesed this canal, and that its presence or absence in A. anostomus is due to
reduction rather than incipient development. Even given this assumption, though, the
quandary remains.
Suspensorium and jaws
QUADRATE-METAPTERYGOID FENESTRA
This is a primitive feature for many characoids, including Abramites, Leporinus and
Schizodon. It is very much reduced or totally absent in all anostomines. (Traces of it
49
are present in Synatptolaemus and P. gracilis.) Thus it is probable that the common
ancestor of the anostomines possessed only a rudimentary quadrate/metapterygoid
fenestra.
PALATINE-QUADRATE RELATIONSHIPS
In most characoids, the palatine and quadrate bones are well separated, but in all
anostomines they are very close to each other and, in two species, P. trimaculatus
and P. irinae, they are actually in contact. This would indicate that the anostomines
are monophyletic (derived from a form which was specialized relative to other
anostomids in the close approximation of the palatine and quadrate). Additionally,
the actual contact of these two bones in P. trimaculatus and P. irinae would suggest
that they are sister groups.
QUADRATE
In all the anostomids I have seen, or of which I have seen figures (e.g., in Géry,
1961, Figs. 11, 17-20, which include Anostomoides, Laemolyta and Rhytiodus
among those I have not personally examined), the ventral margin of the quadrate is
expanded laterally to form a flattened or slightly curved longitudinal shelf or trough.
The shelf begins near the articular condyle of the quadrate, and is produced
posteriorly beyond the rear margin of the main body of that bone. This shelf is
complete in the species of Pseudanos but reduced or absent anteriorly in the
remaining anostomines. Thus it would seem that the lateral shelf was reduced in a
common ancestor of Sartor, Synaptolaemus, Gnathodolus and Anostomus.
ECTOPTERYGOID
A dorsal process arises from the posterior margin of the ectopterygoid in all
anostomids examined, with the exception of the three monotypic anostomine genera
(where this condition would appear to be advanced and indicates that they are
monophyletic).
METAPTERYGOID
In most characoids, the metapterygoid is a vertical sheet of bone. In all anostomines,
the dorsal portion of the metapterygoid either slopes medially or, in A. plicatus,
A. spiloclistron, A. intermedius, Sartor and, to a lesser extent, Gnathodolus, it forms
a flat, almost horizontal shelf dorsally. From the structure of this shelf, the horizontal
nature in Sartor and Gnathodolus may or may not be homologous with that of the
A. plicatus group, but the character is difficult to interpret further. If it is homologous
it would indicate that the genus Anostomus is paraphyletic. The fact that the shelf is
inclined medially in anostomines provides evidence consistent with the hypothesis
that the Anostominae is monophyletic.
MAXILLA
The toothless maxilla of anostomids is usually a thin, curved rod of bone. In all
anostomines except Pseudanos the ventral portion of the maxilla is expanded into a
flat triangular plate, indicating these forms share a common ancestor.
50
OPERCLE
Another character with this distribution is the posterodorsal margin of the opercle,
which is straight in Abramites, Leporinus, Schizodon and Pseudanos but concave in
all other anostomines. This is another indication that the forms with a concave margin
to the opercle are monophyletic.
Hyoid Arch
BRANCHIOSTEGAL RAYS
The species of Pseudanos, together with A. ternetzi and Abramites, have three
branchiostegal rays. All other anostomids I have seen have four. The implication here
is that these forms share a common ancestor which had three branchiostegal rays and,
since the first branchiostegal of A. anostomus is frequently much reduced in size, that
these forms are the sister group of A. anostomus. This interpretation is at variance
with the hypothesis of relationships presented here, based on analysis of all the
available evidence (see p. 49 et seq.). A posterior process on the last branchiostegal
ray iS present in all anostomids examined except Gnathodolus, Sartor and
Synaptolaemus, indicating that these three genera form a monophyletic unit.
EPIHYAL-CERATOHYAL JOINT
The joint is vertical in Pseudanos, Abramites, Leporinus and Schizodon, slightly
oblique in the monotypic genera and at about 45° to the vertical in members of
Anostomus. This transformation series suggests a common ancestor for the monotypic
genera plus Anostomus with a slightly oblique epihyal-ceratohyal joint. The common
ancestor of the species of Anosotmus subsequently increased the angle of the joint to
45° from the vertical, indicating the monophyletic nature of the genus.
UROHYAL
The urohyal is a broad V-shaped bone in all anostomids seen, except in A. plicatus,
A. intermedius and A. spiloclistron, where it is very high dorsally, and indicative of
the common ancestry of these three species.
Cranium
ETHMOID
All anostomines except Pseudanos have a narrow ethmoid (width 53-82 per cent of
length vs width equal to length in the species of Pseudanos and 1|.07—1.30 times
length in the other anostomids examined). This is evidence consistent with the
hypothesis that Anostomus and the monotypic genera form a monophyletic group. In
A. plicatus, A. intermedius and A. spiloclistron the anterior tip of the ethmoid is
hooked, indicating a common ancestor with this condition.
LATERAL ETHMOID
The lateral ethmoid of Abramites, Leporinus, and Schizodon has no notch in its
51
anteroventral margin and is well developed; it is even better developed in Pseudanos.
In all other anostomines the lateral ethmoid is very poorly developed and there is a
distinct notch in the anteroventral margin immediately above the lateral ethmoid-
ectopterygoid ligament. The implications here are that both conditions represent
synapomorphies. The species of Pseudanos represent a monophyletic group since
they shared a common ancestor with a very well-developed lateral ethmoid; the other
anostomines form a monophyletic group because their common ancestor possessed a
poorly-developed, notched lateral ethmoid.
SUPRAOCCIPITAL
All anostomids examined except Pseudanos have the posterior surface of the
supraoccipital grooved in the midline for reception of the neural complex of the
Weberian apparatus. This is indicative of the monophyletic nature of the genus
Pseudanos. This relationship of the species of Pseudanos is further evidenced by the
narrow supraoccipital sulcus which has a distinct rim around. Other anostomines and
anostomids possess a broad, gradual sulcus with no distinct nm.
EXOCCIPITAL-INTERCALAR RIDGE
Abramites, Leporinus, Schizodon, and Pseudanos have a flat area on the exoccipital
between the vagus foramen and the intercalar. In all other anostomines, a distinct
ridge of bone is present between these two points. The parsimonious interpretation is
that these other anostomines shared a common ancestor which possessed the ridge.
PTEROSPHENOID-ORBITOSPHENOID JOINT
The joint between the pterosphenoid and the orbitosphenoid in Abramites, Leporinus,
Schizodon, and Pseudanos passes out laterally, almost at right angles to the axis of
the body. The joint is slightly more anteriorly inclined in Sartor, and more so in the
other anostomines (passing from anterolateral to posteromedial); however, this
character is difficult to quantify.
PARASPHENOID
Amongst characoids in general, the parasphenoid quite often forms a thin strut across
the floor of the orbit. This condition is also found in the three anostomid genera
examined. It is dorsoventrally extended in Pseudanos and in all other anostomines,
and indicates that the subfamily is monophyletic.
Weberian Apparatus
NEURAL COMPLEX
In the species of Pseudanos, the neural complex is a broad flat sheet of bone dorsally
(as opposed to a narrow rod dorsally in anostomids and other anostomines),
indicating that the species of Pseudanos form a monophyletic assemblage.
Bf
Pectoral Girdle
MESOCORACOID JOINT
In anostomids, Anostomus and the monotypic genera, the mesocoracoid is joined
primarily to the coracoid. The species of Pseudanos are thus apparently specialized in
that the joint is about equally shared by the scapula and coracoid.
Caudal Skeleton
HYPURAL FORAMEN
Anostomus plicatus, A. spiloclistron, and A. intermedius all possess a foramen in
hypural one. I have not seen this elsewhere in anostomids or other anostomines, and it
would appear to be a synapomorphy.
NEURAL SPINE
The above three species share the presence of an enlarged lamina of bone on the
anterior face of the neural spine of pu 2 not found in other anostomines or
anostomids. This condition apparently represents another synapomorphy.
Two further characters are of interest here. The three monotypic genera possess
conical or rounded dermal papillae on the lower lips, which I have not seen elsewhere
among characoids. The second character involves colour patterns. I have found
analysis of these patterns impossible without making a priori assumptions of
characters state. Whichever assumption one makes as to the primitive colour pattern
of these fishes, the subsequent interpretations involve reversals of hypothesized
trends of evolution and, further, postulates of convergence. For example, the
anostomid genus Leporinus contains species with both striped (e.g. L. striatus) and
barred (e.g. L. fasciatus) colour patterns, although I hasten to add that I know of no
unequivocable evidence that Leporinus constitutes a monophyletic group. No purpose
would be served by speculation on anostomine colour pattern at this point, especially
when juveniles less than 30 mm SL are not available (so that possible colour changes
with growth could be detected to aid in formulation of hypotheses of character state
change).
The subfamily Anostominae appears to share the following osteological
specializations not found elsewhere in the family: the very close proximity or contact
between the palatine and the dorsal surface of the quadrate; a sloping or horizontal
metapterygoid shelf; the reduction or loss of the metapterygoid-quadrate fenestra, an
ethmoid which is as long or longer than wide (see osteological description for
definition of measurements); and a parasphenoid which possesses a vertical lamina or
keel of bone and is thus more than a simple strut across the orbit. (This character,
while apparently unique to the anostomines among the anostomids, is not unique
among characoids generally.)
I assume the following character states to be specialized within various lineages of
the Anostominae, and provide the evidence consistent with the phylogenetic tree
presented as Figure 68.
BRANCH POINT 1
Pseudanos possesses six specializations which indicate its monophyletic nature:
i) the anterior lamina of the lateral ethmoid is very well developed and is not
notched:
ii) the posterior face of the supraoccipital is not grooved for the reception of the
anterior edge of the neural complex;
iii) the supraoccipital sulcus is narrow and steep-sided, with a distinct rim around
the edge;
iv) the dorsal portion of the neural complex is broad in lateral view;
v) the mesocoracoid is jointed equally to the scapula and coracoid; and
vi) there are three branchiostegal rays (but see Ansotomus ternetzi, which also has
three).
Subjectively, I consider characters v) and vi) weak, that is, quite possibly subject
to convergence.
The lineage containing the three monotypic genera and Anostomus share eight
osteological specializations, which provide evidence that they comprise a monophyle-
tic assemblage:
i) the lateral shelf of the quadrate is incomplete anteriorly;
ii) the maxilla is expanded into a triangular process ventrally;
iii) the posterodorsal surface of the opercle is concave;
iv) the epihyal-ceratohyal joint is inclined at an angle to the vertical;
v) the ethmoid is longer than it is wide;
vi) there is a ridge of bone on the exoccipital between the vagus foramen and the
intercalar;
vii) the joint between the pterosphenoid and orbitosphenoid is more obliquely
inclined; and
vili) the anterior lamina of the lateral ethmoid is poorly developed, but has a
well-developed notch in its leading edge.
Of these, I feel characters ii), iii), iv), and vii) to be weak.
BRANCH POINT 2
Pseudanos trimaculatus and P.. irinae are extremely similar in morphology and most
of the differences between them and P. gracilis appear to be due to specializations in
the latter (i.e. autapomorphies). The former two species are apparently specialized in
that they are the only anostomids in which the palatine and quadrate are in contact. If
this is valid, it would imply that dark spots in the centres of the scales is a primitive
character for the genus, since this colour pattern is found only in P. irinae and
P. gracilis.
BRANCH POINT 3
The monotypic genera (Gnathodolus, Sartor, and Synaptolaemus) share the
following specializations:
i) no dorsal process on the ectopterygoid;
ii) loss of the dorsal process on branchiostegal ray four (i.e. the posterodorsalmost
ray);
ili) conical dermal papillae on the lips of the lower jaw;
54
iv) symphyseal lower jaw teeth at least twice as long as the teeth next to them; and
v) a lower jaw (bony structure) longer than wide.
The genus Anostomus has three possible specializations to separate it from the
monotypic genera. The 45° angle of the ceratohyal-epihyal joint appears to be unique.
The second infraorbital is well developed, and the quadrate height is less than 30 per
cent of its length. The former is subjective, and the latter seems to be negated by
Gnathodolus, where the quadrate height is 7-8 per cent of its length. However, given
the very trenchant specializations shared by Gnathodolus and Sartor (see Branch
Point 4), the bizarre nature of the jaw suspension in the former, and the fact that the
latter and Synaptolaemus have a quadrate height of 32-35 per cent of its length, the
condition in Gnathodolus would seem to be uniquely derived. I therefore think it
extremely unlikely that any species of Anostomus is more closely related to the stem
of the monotypic genera than it is to the other species of that genus.
BRANCH POINT 4
I suggest that Gnathodolus and Sartor are more closely related to each other than
either is to Synaptolaemus because of the following specializations:
i) an extremely elongate and narrow lower jaw;
11) the loss of one (Sartor) or three (Gnathodolus) of the lateral lower jaw teeth;
1ii) the great elongation of the symphyseal lower jaw tooth; and
iv) the very deep median flange on the vomer and parasphenoid.
Set against this is the fact that Sartor and Synaptolaemus, uniquely among
anostomines, have 12 circumpeduncular scales (vs 16). Although this appears to be
an important character, I do not consider it sufficiently ‘‘powerful’’ to offset the
specializations outlined above linking Sartor and Gnathodolus. Given the extensive
and incredible cranial modifications of Gnathodolus, it is not too illogical to suggest
that the 16 circumpeduncular scales in this genus are the result of atavism, a
phenomenon certainly not without apparent precedent in fishes (see, e.g.,
Winterbottom, 1974b:77, 78). The problem, at least at present, is that atavism is an
untestable hypothesis.
BRANCH POINT 5
The genus Anostromus seems clearly divided into two groups of three species each;
A. plicatus, A. spiloclistron and A. intermedius on the one hand and the striped
species (A. anostomus, A. brevior and A. ternetzi) on the other. Specializations in
the former group are:
1) symplectic with dorsal and ventral laminae of bone developed in the region of
the angle;
11) ethmoid hooked anteriorly:
111) symphyseal teeth of lower jaw truncate in individuals larger than 60 mm SL;
iv) a very deep urohyal;
v) foramen present in hypural one; and
vi) broad lamina on anterior face of neural spine of pu 2. The second species group
has a less-deep skull (32-35 per cent of its length) and is unique among anostomines
(but not anostomids) in having a striped colour pattern. It may also be specialized in
having more teeth on ceratobranchial 5 and on the fifth pharyngobranchial toothplate,
but this needs confirmation. The evidence for the monophyletic nature of the striped
55
species thus seems tenuous, but given that the genus Anostomus and the three
monotypic genera represent not only a monophyletic group, but are together the sister
group of Pseudanos (where evidence is stronger) it seems extremely probable that the
striped colour pattern is, in fact, a synapomorphy.
BRANCH POINT 6
The evidence linking A. plicatus and A. spiloclistron is very weak. My decision has
been based on the more consistently truncate nature of the symphyseal lower jaw
teeth, the fact that the replacement teeth for the symphyseal teeth are truncate
(bicuspid in A. intermedius and cusped in most anostomids), and because these two
species have vertical pigmented areas below the lateral line. The latter character may
not represent a synapomorphy. In overall view, the external morphological
similarities are between A. plicatus and A. intermedius while the osteological
similarities are between A. plicatus and A. spiloclistron. However, similarities per se
are not useful in phylogenetic analysis.
BRANCH POINT 7
Since no specimens of A. brevior were available for osteological study, the
hypothesized relationship is extremely tentative. In most of the morphometrics,
A. ternetzi and A. brevior appear to diverge in opposite directions from an
A. anostomus—like bauplan. If, as has been hypothesized under Branch Point 5, the
stiped colour pattern is an advanced character for the Anostominae, then it would
seem reasonable to postulate that complete stripes are more advanced than
intermittent (dorsal) stripes. It is on this basis alone that this section of the phylogeny
is tentatively based.
I have not subdivided the subfamily up into tribes, subtribes, etc., (which would
certainly be possible at this stage) because I believe that there are many other as yet
undescribed species of anostomines in the freshwaters of South America. Their
discovery could create hierarchical problems if a detailed hierarchical classification
were Offered at this time. Instead, I have chosen to follow the intermediary procedure
outlined by Winterbottom (1974b). This system, involving the use of numerical
suffixes, allows the phylogenetic relationships of the contained hierarchical units to
be read off from the formal classification and at the same time permits each
hierarchical category to contain more than two subcategories. It has the additional
advantage that any newly discovered form can be fitted into the existing system
without necessarily having to change the hierarchical levels, the new phylogenetic
information being reflected in the changes in the numercial suffixes. To prevent any
possibilities of confusion, I hasten to add that this is not numerical taxonomy.
56
Subfamily: Anostominae.
Genus: Pseudanos
Species: P. gracilis |
P. trimaculatus 1.1
Pwinae Ll
Synaptolaemus
S. cingulatus 2
Sartor
S. respectus 2.1
Gnathodolus
G. bidens 2.1
Anostomus
A. intermedius 3
. plicatus 3.1
. Spiloclistron 3.1
. ternetzi 4
. anostomus 4.1
. brevior 4.1
pS eta pe se
Acknowledgements
This study was initiated in 1971 by a suggestion from Dr. S. H. Weitzman
(Smithsonian Institution, National Museum of Natural History, USNM). I am
extremely grateful to him for this, for his continued interest, support and patience in
dealing with my neophyte enquiries over the last five years, and for his comments on
the manuscript. Dr. W. L. Fink (Museum of Comparative Zoology, MCZ) offered
many useful and constructive suggestions on the manuscript for which I am most
grateful. Dr. P. H. Greenwood (British Museum (Natural History) — BM(NH)) was
typically generous in his help and encouragement, and kindly commented on the
manuscript, and Mr. Gordon Howes of that institution gave me valuable information
on Gnathodolus. | am greatly indebted to the following for allowing me to make full
use of the specimens in their care: Drs. D. E. Rosen (American Museum of Natural
History — AMNH), J. E. Bohlke (Academy of Natural Sciences of Philadelphia —
ANSP), W.N. Eschmeyer (California Academy of Sciences—CAS and SU),
R. K. Johnson (Field Museum of Natural History—FMNH), F. Mago-Leccia (Museo
de Biologia, Universidad Central de Wenezuela—MBUVC), K. F. Liem and
W. L. Fink (MCZ), M. L. Bauchot (Museum National d’ Histoire Naturelle—MNHN),
H. Britski (Zoological Museum, University of Sao Paulo—MZuUsP), P. Kahsbauer
(Naturhistorisches Museum, Vienna—NMv), M. Boeseman (Rijksmuseum,
Leiden—RMNH), W. Klausewitz (Natur-Museum und _ Forschungs-Institut,
Senckenberg—SMF) and H. Nijssen (Zoological Museum, Amsterdam—ZMaA). Dr.
D. E. McAllister and Mr. C. Gruchy (National Museum of Natural Sciences,
Ottawa), provided much stimulation and many facilities during 1972/73.
57
Dr. S. H. Bowen (then of the Zoology Department, Rhodes University) tirelessly
wrestled with my incomprehension and produced one of the computer programs for
me, while Mr. M. Urry and Dr. P. D. Terry of Rhodes proved invaluable in my
attempts to write the graph-plotting program. To Miss E. M. Tarr, whose dedication
and superb talents have produced the majority of the illustrations, and to Mr.
R. E. Stobbs (both of the Smith Institute, Rhodes University—RUSI) who provided
innumerable first class photographs and X-rays, my sincerest thanks. Mr. Bernardo
Reyes (University of Toronto) kindly translated the Summary and Key to the Species
into Spanish for me.
To my wife, Irina, my deep gratitude for the fortitude with which she has borne
endless hours of esoteric monologues and proofreading.
Support during this study came from a postdoctoral fellowship at the Smithsonian
Institution (1971/72), a second postdoctoral (NRC) at the National Museum of Natural
Sciences, Ottawa (1972/73), and from the CSIR and Rhodes University since that
time. The final draft was prepared with help from the personnel and facilities of the
Royal Ontario Museum’s Department of Ichthyology and Herpetology.
Literature Cited
COCKERELL, T.D.A.
1914 The scales of South American characinid fishes. Annals of the Carnegie Museum 9:92-113.
CUVIER, G. and A. VALENCIENNES.
1849 Histoire naturelle des poissons. Vol. 22, Paris.
EIGENMANN, C.H.
1912. The freswater fishes of British Guiana, including a study of the ecological groupings of
species, and the relation of the fauna of the plateau to that of the lowlands. Memoirs of the
Carnegie Museum 5:11-—578.
FERNANDEZ-YEPEZ, A.
1949 Anostomus ternetzi nuevo anostomido de Sur America, colectado en Palital, Estado Guarico,
Venezuela. Boletin de la Sociedad Venezolana de Ciencias Naturales 11:293—295.
FOWLER, H.W.
1906 Further knowledge of some heterognathus fishes. Part I. Proceedings of the Academy of
Natural Sciences of Philadelphia 58:293-351.
1943. A collection of fresh-water fishes from Colombia, obtained chiefly by Brother Nicéfero
Maria. Proceedings of the Academy of Natural Sciences of Philadelphia 95:223-266.
1945 Colombian zoological survey. Part I — The freshwater fishes obtained in 1945. Proceedings
of the Academy of Natural Sciences of Philadelphia 97:93- 135.
GERY, J.
1960 Contributions a l’étude des poissons characoides (No. 14). Révision de la super-espece
Anostomus anostomus (L.) et description de formes nouvelles: A. brevior et A. anostomus
longus (Erythrinidae, Anostominae). Bulletin du Muséum National d’Histoire Naturelle, 2e
sér, 32:498—S0S.
1961 Contributions a l’étude des poissons characoides 13. Structures et évolution des Anos-
tominae. Bulletin of Aquatic Biology 2:93-112.
1972/73 Notes sur quelques Anostomidae (Pisces, Characoidei) du bassin Amazonien. Vie et
Milieu 23: 143-175.
1977 — Characoids of the world. New Jersey, Tropical Fish Hobbyist. 672 pp.
58
GISTEL, J.
1848 Naturgeschichte des Tierreichs fur hohere Schulen. Stuttgart.
GREENWOOD, P.H., D. E. ROSEN, S. H. WEITZMAN and G. S. MYERS.
1966 __ Phyletic studies of teleostean fishes with a provisional classification of living forms. Bulletin
of the American Museum of Natural History 13:341-455.
GRONOW, L.T.
1754-1756 Museum Ichthyologicum. Lugduni Batavorum. 2 vols.
1763 Zoophylacii Gronoviani fasciculus primus exhibens animalia quadrupeda, amphibia atque
pisces, quae in museo suo adservat, rite examinavit, systematics disposuit, descripsit atque
iconibus illustravit. Laurentius Theodorus Gronovius. Lugduni Batavorum.
1854 Catalogue of fish collected and described by L. T. Gronow, now in the British Museum, ed.
by J. E. Gray. London. 196 pp.
HENNIG, W.
1966 Phylogenetic systematics. Chicago, University of Illinois Press. 261 pp.
KNER, R.
1859 Zur Familie der Characinan. III. Folge der Ichthyologischen Beitrage. Denskriftender
Kaiserlichen Akademie der Wissenschaften 17: 136-182.
KNOPPEL, H.A.
1972 Zur Nahrung tropischer Stsswasserfische aus Sudamerika. Amazoniana 3:231-246.
LINDBERG, G.U.
1974 Fishes of the world. New York, John Wiley. 545 pp.
LINNAEUS, C.
1758 Systema naturae. 10th ed. Holmiae.
LOWE, R.H. (McCONNELL)
1964 The fishes of the Rupununi savanna district of British Guiana, South America. Part 1.
Ecological groupings of fish species and effects of the seasonal cycle on the fish. Journal of
the Linnean Society (Zoology) 45: 103-144.
MAGO-LECCIA, F.
1970 Lista de los peces de Venezuela, incluyendo un estudio preliminar sobre la ictiogeografia del
Pais. Caracas, Ministerio de Agricultura y Cria, Oficina Nacional de Pesca. 283 pp.
MYERS, G.S.
1927 Descriptions of new South American fresh-water fishes collected by Dr. Carl Ternetz. Bulle-
tin of the Museum of Comparative Zoology 68: 107-135.
1950 Studies on South American fresh-water fishes. II. The genera of anostomine characids. Stan-
ford Ichthyological Bulletin 3: 184-198
MYERS, G.S. and A. L. de CARVALHO.
1959 A remarkable new genus of anostomin characid fishes from the upper Xingu in central
Brazil. Copeia (1959): 148-152.
NELSON, G. J.
1969 = Gill arches and the phylogeny of fishes, with notes on the classification of vertebrates. Bulle-
tin of the American Museum of Natural History 141:475-552.
1973 Relationships of clupeomorphs, with remarks on the structure of the lower jaw of fishes. /n
Greenwood, P.H., R. S. Miles, and C. Patterson, eds., Interrelationships of fishes. London,
Academic Press, pp. 333-349.
PATTERSON, C.
1975 The braincase of pholidorphorid and leptolepid fishes, with a review of the actinopterygian
braincase. Philosophical Transactions of the Royal Society of London, Series B, Biological
Sciences, 269:275-579.
ae
RAFINESQUE, C.S.
1815 Analyse de la nature, ou tableau de l’univers et des corps organisés. Palerme. 224 pp.
RAMIREZ, E.M.V.
1957 Nuevas especies para la fauna ictiologia Venezolana. Boletin de la Sociedad Venezolana
Ciencias Naturales 18:157-162.
RINGUELET, R.A., R. H. ARAMBURU, and A. A. de ARAMBURU.
1967 Los peces Argentinos de Agua dolce. La Plata, Buenos Aires Gobernacion, Comision de
Investigation Cientifica. 602 pp.
ROBERTS, T.R.
1969 Osteology and relationships of characoid fishes, particularly the genera Hepsetus, Salminus,
Hoplias, Ctenolucius, and Acestrorhynchus. Proceedings of the California Academy of
Sciences, 4th Ser., 36:391—500.
1974 Osteology and classification of the neotropical characoid fishes of the families Hemiodontidae
(including Anodontidae) and Parodontidae. Bulletin of the Museum of Comparative
Zoology 146:411-472.
SCOPOLI, G.A.
1777 Introductio ad historiam naturalem. Prague. 506 pp.
STEINDACHNER, F.
1882 Beitrage zur Kenntiss der Flussfische Sudamerika’s. 11. Beschreibungen von 51 Fisch-
Arten. Denkschriftender Akademie Wissenschaften zu Wien 43: 103-146.
SWAINSON, W.
1839 The natural history and classification of fishes, amphibians and reptiles, or monocardian
animals. London. 2 vols.
WEITZMAN, S.H.
1962 The osteology of Brycon meeki, a generalized characid fish, with an osteological definition of
the family. Stanford Ichthyological Bulletin 8: 1-77.
1964 Osteology and relationships of South American characid fishes of subfamilies Lebiasininae
and Erythrininae with special reference to the subtribe Nannostomina. Proceedings of the
United States National Museum 116: 127-170.
WINTERBOTTOM, R.
1974a A new species of anostomid characoid fish, Anostomus spiloclistron, from the Nickerie river
system of western Surinam (Pisces, Cypriniformes, Anostomidae). Beaufortia 21:153-
163.
1974b = The familial phylogeny of the Tetraodontiformes (Pisces: Acanthopterygii) as evidenced by
their comparative myology. Smithsonian Contributions to Zoology 155:1-201.
60
Appendix I. List of Material Examined
Anostomus anostomus
GUYANA. AMNH 7086, 2, 56.3-93.1 mm SL, Essequibo River system, Potaro
River at Erukin Creek; coll: C. H. Eigenmann, 1908. AMNH 8225, 1, 100.8 mm SL,
Kurupung River (tributary of Mazaruni River ?); coll: H. Lang. AMNH 17601, 1,
59.6 mm SL, Essequibo River system, Kuyuwini River; coll: R. Snedeger, Dec. 2,
1937. AMNH 17648, 2, 57.7—-85.1 mm SL, Essequibo River system, Kuyuwini River,
between mouth and Marudi Creek; coll: R. Snedeger, Dec. 9, 1937. AMNH 31027, 4,
36.1-56.0 mm SL, Demerara River, 1934. AMNH 31030, 4, 42.0-107.0 mm SL,
Demerara River System, at Wismar. Aug. 1935. AMNH 31031, 40, 40.1-75.7 mm
SL, Demerara River system at Wismar, 1934. BM(NH) 191 1-10-31-462, 81.0 mm SL,
Essequibo River system at Crab Falls; coll: C. H. Eigenmann, Oct. 31, 1911.
BM(NH) 1936.44: 15-16, 2, 41.2-59.8 mm SL, Demerara River system at Wismar;
coll: Pinkus, Apr. 4, 1936. BM(NH) 1972.10.17: 1466, 1, 89.4 mm SL, Essequibo
River system. Potaro River at Amatuk, swamp/creek; coll: R. Liley, Oct. 17, 1972.
CAS 15777, 3, 59.6-87.7 mm SL, Essequibo River system, Potaro River at Erukin.
CAS 15778, 2, 67.4-72.5mm SL, Essequibo River system, Potaro River at
Tumatumari. CAS 15780, 2, 45.7-68.8 mm SL, Essequibo River system at Crab
Falls. CAS 15781, 1, 84.5 mm SL, Essequibo River system, Potaro River, creek
below Potaro landing. FMNH 7316, 1, 66.3 mm SL, Essequibo River System at Crab
Falls; coll: C. H. Eigenman, 1908. FMNH 50161, 3, 78.8-86.8 mm SL, Corantiyne
River system, New River; coll: E.R. Blake, Oct. 1938. FMNH 53384, 2,
49.2-74.3 mm SL, Essequibo River system at Crab Falls; coll: C. H. Eigenmann,
1908. FMNH 53385, 2, 51.3-76.7 mm SL, Essequibo River System, Potaro River at
Tumatumari; coll: C. H. Eigenmann, 1908. FMNH 53386, 1, 78.3 mm SL, Essequibo
River system, Potaro River at Potaro landing; coll: Shideler, 1908. FMNH 53387, 1,
71.4 mm SL, Essequibo River system, Potaro River at Kangaruma; coll: Shideler,
1908. FMNH 53388, 2, 51.0-97.2 mm SL, Essequibo River system, Potaro River,
Erukin Creek; coll: C. H. Eigenmann, 1908. FMNH 53389, 1, 57.8mm SL,
Essequibo River system, Potaro River at Amatuk; coll: C. H. Eigenmann, 1908.
FMNH 69600, 2, 69.4-73.6 mm SL, Essequibo River system, Potaro River at Potaro
landing; coll: C. H. Eigenmann, 1908. Mcz 29921, 1, 85.3 mm SL, Essequibo River
system at Crab Falls; coll: C. H. Eigenmann. su 21772, 1, 71.1 mm SL, Essequibo
River system at Crab Falls; coll: C. H. Eigenmann, 1908. ZMA 102.227, 1, 71.1 mm
SL, Essequibo River system, Potaro River at Erukin Creek; coll: C. H. Eigenmann,
1908.
PERU. ANSP 112491, 1, 93.5 mm SL, Amazon River system, Concordia, coastal
parts of lower Nucuray River into Maranon River; coll: Manuel, Oct. 1958. MNHN
1961-1128, 2, 91.6-102.4 mm SL (paratypes of A. a. longus). Amazon River
system, confluence of Nucuray and Maranon Rivers near Concordia; coll: Manuel,
Oct~ 1958.
SURINAM. RMNH 18497, 1, 88.9 mm SL, Saramacca River system, upper
Saramacca River at Toegoemoetoe; coll: de Kok Exped., Feb. 15, 1903. RMNH
18498, 1, 90.5 mm SL, data as above; coll: de Kok Exped., Feb. 9, 1903. RMNH
uncat., 8, 69.6-82.6 mm SL, Corantijn River system, Kabelebo River, tributary
below Avanovero Falls; coll: M.Boeseman, Apr. 6, 1971. RMNH uncat., 8,
6]
71.0-86.1 mm SL, data as above; coll: M. Boeseman, Apr. 10, 1971. RMNH uncat.,
1, 55.9 mm SL, Suriname River system, Sara River, Kurambaolo Creek above dam;
coll: M. Boeseman, Dec. 22, 1963. RMNH uncat., 1, 84.5 mm SL, Tapanahoni,
2.5 km downstream from Palomeu Airport; coll: G. F. Mees, Nov. 30, 1965. RMNH
uncat., 1, 68.3 mm SL, Suriname River at Brokopondo; coll: M. Boeseman. RMNH
uncat., 2, 72.5—93.2 mm SL, Suriname River system, rapids at Brokopondo; coll:
M. Boeseman. RMNH uncat., 1, 80.0 mm SL, Suriname River system, 1—2 km from
outlet of Gran (=Marowijne) Creek; coll: M.Boeseman. RMNH uncat., 2,
72.2-81.2 mm SL, Suriname River system, Gran Creek 12 km above outlet; coll:
M. Boeseman. RMNH uncat., 2, 64.5-68.0 mm SL, Saramacca River system,
stagnant pool below Feddiprati Rapids; coll: M. Boeseman. RMNH uncat., 2,
Suriname River system, tributary of Gran Creek near shore of Brokopondo Lake;
coll: M. Boeseman. ZMA 105.293, 4, 47.6-76.6 mm SL, Suriname River system.
Marowijne Creek, rotenone, sand bottom to 1.5 m; coll: H. Nijssen, Oct. 20, 1966.
ZMA 105.407, 1, 83.9 mm SL, Suriname River system, Gran Rio 2.5 km NE of
Awaradam, rotenone, 2 m wide, 100 cm deep, sand bottom; coll: H. Nijssen, Jan.
28, 1967. ZMA 105.418, 4, 80.2-90.6 mm SL, Suriname River system, Gran Rio
4km NE of Awaradam, rotenone, 6 m wide, 1.5m deep, sand bottom; coll:
H. Nijssen, Jan. 31, 1967. ZMA 105.450, 8, 67.4-88.9 mm SL, Suriname River
system, Gran Rio | km N of Dombaai, rotenone, 5 m wide, | m deep, sand and mud
bottom; coll: H. Niyssen, Jan. 30, 1967. ZMA_ 105.526, 4, 62.5-94.2 mm SL,
Coppename River system, rotenone, 4 m wide, 1.5 m deep, sand and rock bottom;
coll: H. Nijssen, May 9, 1967. ZMA_ 105.527, 1, 82.6 mm SL, Coppename River
system, rotenone, 5 m wide, | m deep, rock and sand bottom; coll: H. Nijssen, May
10, 1967. ZMA 106.529, 8, 49.7-81.2 mm SL, Coppename River system, 4 m wide,
1 m deep, sand and mud bottom; coll: H. Nijssen, May 18, 1967. ZMA 106.530, 7,
63.5-89.7 mm SL, Coppename River System, rotenone, 5 m wide, 2 m deep, sand
and mud bottom; coll: H. Nijssen, May 19, 1967. ZMA 105.595, 2, 73.8-79.3 mm
SL, Saramacca River system, Kleine Saramacca River 14 km ESE of mouth,
rotenone, 80 m wide, 2 m deep, sand bottom; coll: H. Nijssen, Feb. 28, 1967. ZMA
105.600, 3, 71.5-75.9 mm SL, Saramacca River system, Toebaka Creek near Kleine
Saramacca mouth, rotenone, 4m wide, | m deep, sand and mud bottom with
branches; coll: H. Nijssen, Mar. 2, 1967. ZMA 105.651, 4, 70.0-87.1 mm SL,
Saramacca River system, creek on Kleine Saramacca River 13 km ESE from mouth,
rotenone, 3 m wide, 1 m deep, sand and rock bottom, stagnant; coll: H. Nijssen,
Feb. 28, 1967. ZMA 105.668, 1, 62.5 mm SL, Saramacca River system, Kleine
Saramacca River 11 km ESE of mouth, rotenone, 4 m wide, | m deep, sand and rock
bottom; coll: H. Nijssen, Feb. 27, 1967. ZMA 105.780, 32, 61.5-90.3 mm SL,
Suriname River system, Awara Creek, rotenone, 8 m wide, 1.5 m deep, sand
bottom; coll: H. Nijssen, Mar. 18, 1967. ZMA 105.789, 2, 51.7-72.5 mm SL,
Suriname River system, | km S of Botopasi, rotenone; coll: H. Nijssen, Mar. 22,
1967. ZMA 105.799, 13, 73.0-89.9 mm SL, Suriname River system, Parwapa Creek
2.5 km N of Botopasi, rotenone, 8 m wide, 2 m deep, sand bottom; coll: H. Nijssen,
Mar. 20, 1967. ZMA 106.524, 3, 65.1-93.8 mm SL, Suriname River system, Jenjee
Creek 7.5 km N of Botopasi, rotenone, 3 m wide, 1.2 m deep, sand bottom; coll:
H. Nijssen, Mar. 21, 1967. ZMA 106.525, 1, 56.0 mm SL, Suriname River system
7.5 km N of Botopasi at rapids, rotenone, rock bottom; coll: H. Nijssen, Mar. 21,
1967. ZMA 106.528, 25, 47.7-84.4 mm SL, Coppename River system near
62
Wilhelmina Mtns, rotenone, 15 m wide, 4 m deep, sand bottom; coll: H. Nissen,
May 17, 1967.
VENEZUELA. SU 16187, 1, 43.5 mm SL, Orinoco River system, rapids between
Atabapo and D’Autures; coll: C. Ternetz, April, 1925. SU 16274, 2, 46.6-52.2 mm
SL, Venezuela, Orinoco River system, bifurcation with Casiquiare River at Laja
Tama Tama; coll: C. Ternetz, Mar. 26, 1925.
Anostomus brevior
FRENCH GUIANA. MNHN 01-405, 1 (holotype), 86.5 mm SL, French Guiana,
Oyapok River system at its junction with the Camponi (= Camopi?) River. Coll:
Geay, 1901. MNHN 01-406/409, 4 (paratypes), 69.1-81.5 mm SL, data as for
holotype.
Anostomus intermedius
BRAZIL. Holotype: SMF 10651, 77.7 mm SL, Brazil, Amazon River system, upper
Xingu River, below the cataracts near Suya-Missu or Paranajuba; coll: H. Schultz,
Nov. 15, 1960.
Paratypes: BM(NH) 1977.1.7:1, 74.5 mm SL, collected with the type. SMF 13618,
14, 49.0-92.0 mm SL, collected with the type. USNM 216593, 78.7 mm SL,
collected with the type.
Anostomus plicatus
GUYANA. As for Winterbottom (1974a), consisting of AMNH 17602, 17605, 17610,
17646 and the following paratypes: CAS 27647, 27648, 27649, 27650, FMNH 53394,
53395 and 53396, all 12 specimens being from the Essequibo River system.
Anostomus spiloclistron
SURINAM. As in Winterbottom (1974a), consisting of ZMA 112.685 (holotype) and
ZMA 105.776, ZMA 105.777, ANSP 124334, CAS 27725 and USNM 209432
(paratypes), all 16 specimens being from near the Stondansi Falls, Nickerie River.
Anostomus ternetzi
I have not examined the types of this species. A holotype and single paratype are in
the collections of the Museo de Ciencias Naturales de Caracas, Venezuela (numbers
46.001 and 46.002 respectively).
BRAZIL. MZusP 5161, 2, 36.8-37.2 mm SL, Amazon River system, Surumu River
at Surumu (junction with Branco River); coll: Alvarenga, Oct., 1966. MZUSP 9989, 3,
64.4—74.0 mm SL, Amazon River system, Tapajos River, Igarapé Apéu (Boa Vista,
Para.); coll: P. E. Vanzolini, Feb. 3-4, 1964. Mzusp 9990, 12, 60.3—90.1 mm SL,
Pana River system, Capim River near mouth at Belém do Para; coll: R. Takase. SMF
10650, 10, 46.3-64.7 mm SL, Amazon River system, upper Rio Xingu, below
cataracts near Suyo Missu (or Paranajuba); coll: H. Schultz, 15 Nov., 1960. SMF
10653, 5, 46.2-60.9 mm SL, data as above.
GUYANA. AMNH 17650, 1, 71.7 mm SL, Terry-Holden Expedition, 1937-1938.
ANSP 39788-90, 3, 64.1-73.6 mm SL, Essequibo River System, Rupununi River;
coll: J. Ogilvie, 1912. BM(NH) 1861-1.2.21:90, 1, 56.8 mm SL, Essequibo River
system; coll: Ehrhardt, Jan. 2, 1864. BM(NH) 1972-7.27: 127-128, 2, 46.9-53.7 mm
SL, Essequibo River system, Rupununi River, Simoni Creek at Tacupas, just north of
63
Karenambo; coll: R. H. Lowe-McConnell, May, 1961. BM(NH)1972-7-27:129, 1,
76.5mm SL, Essequibo River system, Manar stop-off; coll: R.H. Lowe-
McConnell. BM(NH) 1972-7-27:130, 1, 64.5 mm SL. Essequibo River system,
Rupununi River at Karenambo; coll: R. H. Lowe-McConnell. BM(NH) 1972-7-
27:131, 1, 44.4 mm SL, Essequibo River System, Rupununi River, Moreby Creek;
coll: R. H. Lowe-McConnell. BM(NH) 1972-7-27: 132-133, 2, 54.1-67.9 mm SL,
Essequibo River system, Rupununi River, Arakwais Creek; coll: R. H. Lowe-
McConnell.
SURINAM. RMNH uncat., 3, 53.2-56.0 mm SL, Marowijne River system, upper
Tapanohoni River, rotenone; coll: G. F. Mees, Nov. 27, 1965. RMNH uncat., 2,
56.1-100.2 mm SL, Marowijne River system, Tapanohoni River 2 km downstream
from Paloemeu River mouth; coll: G. F. Mees, Nov. 17, 1965.
VENEZUELA. CAS 20093, 1, 56.9 mm SL, Orinoco River system, rapids between
Atabapo and D’Autures; coll: C. Ternetz, Apr. 1925. CAS 20094, 1, 62.0 mm SL,
Orinoco River system at Caicara; coll: C. Ternetz, May 1, 1925. CAS 20095, 4,
48.7-71.0, Orinoco River system at bifurcation, Tama Tama rocks; coll: C. Ternetz,
Mar. 26, 1925. SU 60681, 2, 44.9-51.6 mm SL Orinoco River system, Orinoco
River at ‘Kiratare: ‘coll:’C. Ternetz, Mar, 30, 1925.
Gnathodolus bidens
VENEZUELA. CAS 20087, (holotype), 108.8 mm SL, Casiquiare River at Chemoni
(near the bifurcation with the Orinoco); coll: C. Ternetz, Mar. 18, 1925. CAS 27651,
(paratype), 73.4 mm SL, Orinoco River System at Laja Tama Tama (near bifurcation
with the Casiquiare River); coll: C. Ternetz, Mar. 24, 1925. McCZ 31566, (paratype),
88.3 mm SL, collected with CAS 27651.
Pseudanos gracilis
BRAZIL. NMV 57-119, 1 (holotype), 69.2 mm SL, Amazon River system, Guaporé
River; coll: Natterer, 1832—1837. BM(NH) 1912-9-4-11, 1, 47.9 mm SL, Amazon
River system, Rio Negro at Manaus; coll: Arnold, Sept. 4, 1912.
VENEZUELA. CAS 20105, 4, 86.2—-136.4 mm SL, Orinoco River system, mouth of
Atabapo River at San Fernando; coll: C. Ternetz, Apr. 8, 1925. CAS 20107, 1,
95.8 mm SL, Orinoco River system, mouth of Atabapo River at San Fernando; coll:
C. Ternetz, Apr. 8, 1925. CAS 20108, 2, 45.7-51.2 mm SL, Orinoco River system,
rapids at Chorro Salata; coll: C. Ternetz, Apr. 16, 1925. CAs 20111, 1, 66.0 mm SL,
Ormoco. River system at Kiratart; coll: C. Vernetz, Mar? 307°1925-"Su 16275)
74.2 mm SL, Orinoco River system, at Kiratari; coll: C. Ternetz, Mar. 30, 1925. SU
16276, 2, 41.1-106.6 mm SL, Orinoco River system, rapids at Chorro Salata; coll:
C. Temetz,; Apr: 16,1925. su 162773" 15 115-7 mm! SEeY Ormeco River system:
Cucuhy, San Carlos de Rio Negro: coll: "©Wemietz, Feb: 22> 1925. sU Tol 7orme
152.5 mm SL, Orinoco River system, mouth of Atabapo River at San Fernando; coll:
C. Ternetz, Apr. 9; 1925. su 16279,- 1, 150.2"mm' SL,” Orineco=River system,
bifurcation with Casiquiare River at Laja Tama Tama; coll: C. Ternetz, Mar. 24,
1925. SU 16280, 7, 68.0-160.5 mm SL, Orinoco River system, mouth of Atabapo
River at San Fernando; coll: C. Ternetz, Apr. 7-8, 1925. SU 54602, 1, 79.5 mm SL,
Orinoco River system, mouth of Cano de Quiribana at Caicara; coll: C. Ternetz, May
3 O25%
64
eudanos irinae
UYANA. Paratypes: AMNH 14359, 1, 71.3 mm SL, Essequibo River system at
ockstone; coll: Pinkus Expedition, March, 1938. AMNH 17612, 20, 66.8—
10.3 mm SL, Essequibo River system, Rupununi River just below Yupukarri near
aranambo (McTurk’s ranch); coll: R. Snedeger (Terry-Holden Expedition),
137-38. BM(NH) 1911-10-31-463, 1, 53.6 mm SL, Essequibo River system at Crab
lls; coll: C. H. Eigenmann, 31 Oct., 1911(?). BM(NH) 1972.7.27. 125-126, 2,
}.3-71.3 mm SL, Essequibo River system, Rupununi River, Crane Pond at
aranambo; coll: R. H. Lowe-McConnell, 27 Jul., 1972. FMNH 53390, 1, 97.1 mm
., Twoca Pan; coll: Grant, 1908. FMNH 53391, 1, 71.0 mm SL, Essequibo River
stem at Crab Falls; coll: C. H. Eigenmann, 1908. FMNH 53392, 1, 56.0 mm SL,
ssequibo River system at Rockstone; coll: C. H. Eigenmann, 1908. FMNH 53392, 1,
».0 mm SL, Essequibo River system at Rockstone; coll: C. H. Eigenmann, 1908.
ENEZUELA. Holotype: SU 58809, 70.6 mm SL, Orinoco River system, Orinoco
ver at bifurcation with Casiquiare River, Laja Tama Tama; coll: C. Ternetz, 24
aris. 1925.
Paratypes: CAS 15771, 1, 73.3 mm SL, Orinoco River System, Cano de Quiribana
to Orinoco; coll: C. Ternetz, 13 May, 1925. CAS 15787, 1, 78.8 mm SL, Monagas
ovince, ?Acio Queribana. CAS 20097, 10, 60.9-75.4 mm SL, Orinoco River
stem, Orinoco River at bifurcation with Casiquiare River, Laja Tama Tama; coll:
_ Ternetz, 20 Apr., 1925. CAS 20098, 6, 68.1—92.6 mm SL, Orinoco River system,
rinoco River at Cano de Quiribana; coll: C. Ternetz, 13 May, 1925. CAs 20100, 1,
.5 mm SL, Orinoco River system at Carcara; coll: C. Ternetz, 1 May, 1925. su
281, 9, 59.5-77.0 mm SL, Orinoco River system, Orinoco River at bifurcation
ith Casiquiare River, at Tama Tama Rocks and Lake; coll: C. Ternetz, 20—26 Apr.,
25. SU 16282, 1, 77.2 mm SL, Casiquiare River at Buenavista; coll: C. Ternetz,
| Feb., 1925. SU 68303, 2, 75.7-75.9 mm SL, collected with the holotype.
eudanos trimaculatus
RAZIL. FMNH 69596, 19, 47.7-92.5 mm SL, Amazon River system, Guaporé
ver at Maciel; coll: Haseman, Jul. 30, 1909. FMNH 69598, 1, 59.3 mm SL,
mazon River system at Santarem, south bank just downstream from junction of
mazon and Tapajos Rivers; coll: Haseman, Dec. 15, 1909. Mcz 20444, 1, 64.2 mm
., Amazon River system at Obydos (=Obidos); coll: Thayer Expedition. NMV
692, 1 (holotype), 155.2 mm SL, Mato Grosso. USNM 209430, 3, 61.2—77.5 mm
., Para River system, Capim River near mouth, at Belém do Para; coll:
.R. Axelrod, Nov. 1963.
CUADOR. BM(NH) 1970.4.3.33-44, 11, 40.7-106.7 mm SL, Jatuncacha, Amazon
iver system, Napo River at Lake Jatun (=Jatuncacha); coll: D. Kershaw, 1969.
4RU. ANSP 137593, 1, 69.3 mm SL, Amazon River drainage, Rio Nanay at Loreto
icinity of Iquitos) well above Morana Creek and 14 km from the Amazon,
tenone; coll: M. Horn, Oct. 19, 1955 (Catherwood Expedition). ANSP 137594, 4,
!.4-67.8 mm SL, data as above. ANSP 137595, 1, 62.1 mm SL, locality as above;
Il: C. G. Chaplin & party, Oct. 14, 1955 (Catherwood Expedition). BM(NH)
168 .8.12.30:1, 1, 71.5 mm SL, Amazon River drainage, Rio Nanay near mouth,
th of Iquitos; coll: R. Heath, Dec. 30, 1968. CAS 15774, 2, 55.4-59.5 mm SL,
mazon River system at Iquitos; coll: P. S. Morris, 1922. su 16284, 2,
!.7-102.3 mm SL, Amazon River system, Ampiyacu River near Pebas (?); coll:
65
W. G. Scherer, Jul. 25, 1941. SU 36917, 1, 101.3 mm SL, locality as above; coll:
W. G. Scherer, Sept. 10, 1937. USNM 175912, 1, 67.6 mm SL, locality as above;
coll: W. G. Scherer, Jan. 18, 1935.
Sartor respectus
I have not seen the holotype of this species, which is in the collection of the Museum
Nacional, Rio de Janeiro. There are no paratypes.
BRAZIL. SMF 10652, 3, 60.0-87.7 mm SL, Amazon River system, upper Xingu
below cataracts near Suyu Missu (or Paranajuba); coll: H. Schultz, Nov. 15, 1960.
Synaptolaemus cingulatus
BRAZIL. SMF 10222, 2, 51.1-77.6 mm SL, Amazon River system, upper Xingu,
below cataracts near Suyu Missu (or Paranajuba); coll: H. Schultz, 15 Nov., 1960.
VENEZUELA. CAS 2014, 3 (paratypes), 75.0-108.5 mm SL, Orinoco River system,
Orinoco River at Laja Tama Tama (at bifurcation with Casiquiare River); coll:
C. Ternetz, Mar. 24, 1925. MBUCV V-4252, 2, 71.2-90.0 mm SL, Orinoco River
system, Rio Paragua, Auraima Rapids (State of Bolivar), rock bottom, rotenone,
25°C; coll: J. Moscé and A. Machado, Oct. 7, 1966. SU 16122, 1 (holotype),
70.1 mm SL, Orinoco River system, upper Orinoco River at Laja Supira; coll:
C. Ternetz, Apr. 6, 1925.
Appendix 2. Cleared and Stained Material
Note: In the figure legends, catalogue numbers and sizes of specimens are given only
where ambiguity might otherwise arise.
Anostomus anostomus
3, 74.0-79.5 mm SL, RUSI 5522. No data (aquarium specimens).
Anostomus brevior
No material.
Anostomus intermedius
1 (paratype), 69.2 mm SL, SMF 13618, Brazil, upper Xingu River.
Anostomus plicatus
1, 73.5 mm SL, AMNH 17602, Guyana, Essequibo River.
Anostomus spiloclistron
1 (paratype), 82.5 mm SL, ZMA 105.777, Surinam, Nickerie River.
Anostomus ternetzi
2, 60.3-86.0 mm SL, MZusP 9990, Brazil, Para River.
Gnathodolus sp.
1, 51.5 mm SL, BM(NH) 1972.12.5:5, aquarium specimen.
Pseudanos gracilis
1, 91.3 mm SL, su 16280, Venezuela, Orinoco River.
Pseudanos irinae
1 (paratype), 74.0 mm SL, CAS 20097, Venezuela, Orinoco River. 1 (paratype),
66.2 mm SL, SU 16281, Venezuela, Orinoco River.
Pseudanos trimaculatus
2, 43.3-71.6 mm SL, BM(NH) 1970.4.3:33-44, Ecuador, Napo River. 3, 52.1-
86.0 mm SL, RUSI 5521, Brazil, Guaporé River (ex FMNH 69596).
Sartor respectus
1, 65.7 mm SL, SMF 10657, Brazil, upper Xingu River.
66
Synaptolaemus cingulatus
1, 71.2 mm SL, MBUVC V-4252, Venezuela, Paragua River.
COMPARATIVE MATERIAL OF OTHER ANOSTOMIDS
Abramites hypselonotus
2, RUSI 5523, Brazil, Santerem.
Leporinus reinhardti
2, RUSI 5526, Brazil, San Francisco River.
Leporinus striatus
2, RUSI 5525, Bolivia, Cerro del Amboro.
Schizodon isognathus
1, RUSI 5524, Brazil, Bastos.
Appendix 3. Gazetteer of Localities Mentioned in the Text
Note: Where only the name of a river is given, the coordinates listed are at the mouth
of that river.
BRAZIL
Belém do Para 1°27’S, 48°29'W
Guaporé River 11°55'S, 65°02’W
Igarapé Apéu 3723:5,.5) 30 W
Manaus 3°06’S, 60°00'W
Obidos 1952'S; 55°30? W.
Paranajuba 1227S ..53°09 W.
Santarem 2°26'S, 54°41'W
Surumu 3°24'N, 60°20'W
Suyu Missu 11°22’S, 53°09’W
ECUADOR
Jatuncacha (Lake) 1905'S, 73°27-W
FRENCH GUIANA
Camponi (=Camopi?) B12 Ny 52°17 W.
GUYANA
Amatuk Dlt8 N; 59°18 W
Crab Falls 5°24'N, 58°57'W
Crane Pond 3°46'N, 59°18’W
Demerara River
Erukin Creek
Kangaruma
Karanambo
Kurupung River
Kuyuwini River
Marudi Creek
6°46'’N, 58°10’W
5°20°N, 59°16’ W
5717'N,, 59° 10°W
3°46'N, 59°18’W
6°14’N, 60°10’W
2°14'N, 58°19’'W
DLS’ N, 58°12 W
67
New River
Potaro Landing
Rockstone
Rupununi River
Tacupas
Tumatumari
Twoca Pan
Wismar
Yupukarri
PERU
Ampiyacu River
Iquitos
Loreto
Nucuray River
SURINAM
Avanovero Falls
Awara Creek
Botopasi
Brokopondo
Coppename River
Gran Creek
Gran Rio
Jenjee Creek
Kleine Saramacca River
Kurambaolo Creek
Marowijne Creek
Paloemeu River
Parwapa Creek
Stondansi Falls
Tapanahoni
Toeboeka Creek
Toekoemoetoe
Wilhelmina Mountains
VENEZUELA
Atabapo .
Auraima Rapids
Buenavista
Caicara
Cano de Quiribana
D’ Autres
Laja Tama Tama
San Carlos de Rio Negro
San Fernando
Tama Tama Rocks
68
S19 NS 37 32.
5°20'N, 59°05’W
6°00'N, 58°30'W
4°02'N, 58°32'W
3°45'N, 59°17'W
a 17 N; 38°59 W
4°02’N, 58°32'W
5°58'N, 58°36'W
3°40'N, 59°21'W
3°20.S;-7 1-507 W
3S) 4S5¢ 13 ASW
3°40'S, 73°15’W
4°55'S, 75°32'W
4°49'N, 57°24'W
4°15'’N, 53°27 W
4°14'’N, 55°27’'W
5°05'N, 55°04’ W
3°51'N, 567007 W.
5°34'N, 55°07’ W
4°05’N, 55°37'W
4°17'N, 55°25'W
4°58’'N, 55°33'W
4°30’N, 54°57'W
a 34'N,, 55°07 W
S21 Ny 55°26) W
4°15’N, 55°26'W
5°09'N, 56°29’ W
4°22'N, 54°27'W
5°00’'N, 55°34'W
4°12’N, 55°54'W
3°49'N, 56°57'W
4°03'N, 67°45'W
6°17'N, 63°35'W
1°58'N, 66°42'W
7°38'N, 66°10’ W
7°38'N, 66°10’ W
8°37 N; 62°15" W
3°08'N, 65°52’W
1°54’N, 67°06’ W
4°03'’N, 67°45’'W
3°08'N, 65°52'W
(S€) (Or-6¢£) (Or-8¢) (69-L9) (9¢-Zpr) (II-O1) (07-81) (O€-62) (€S-7S) (€S-ZS) ¢=uU
OSE €°6£ €°6£ 1°89 €V 8°01 LSI 0'0€ Les €°7S snizadsad °§
(S€-v¢) (6€-LE) (O€-¥7Z) (9-49) (8t—-Op) (II-O1) (61-91) (67-LZ) (ps-IS) (9¢-ZS) g9=u
Cre 6'LE 8°97 8°89 bby 9°01 O'LI 182 ¢ 7S lps snjpjnsuid °§
(It-8€) (pr-I) (pb>-r¢) (66-19) (pr-ZE) (ZI-6) (SI=ZD) (ZE-1Z) (09-ZS) (LS-8p) Lp =u
1'6€ vt I'8€ €°08 SARS vO el Le oss pis SNIDINIDUIAI *
(It-6€) (St-Ip) (Iv-S€) (€6-€L) (Zt-r¢) (ZI-6) (Sera) (67-SZ) (gs-€s) (pS-8p) 6s =u
0'0r TEP CLE C18 0'°8€ vol lel (GIY6 OSS EIS apuldl *
(Zr-0r) (Lv-€p) (Ov-0€) (98-89) (€v-Se) (OI-8) (pI-I1) (O€-¥2) (LS-0S) (SS-8p) 97 =U
OP i a7 OSE CEL CSE v'6 Tarek €°97 b's 60S Sy19043
(C€) (6€) (Zt-6¢) (06-98) (9r-€p) (pI-€1) (1S) (1€-0€) (LS-+S) (€S-6h) €=u
O'SE 0°6£ € Or 9°L8 9’ vb EE 0°91 9°0€ oss SIS suapiq “9D
(S€-L¢) (Zt-6€) (p€-672) (69-79) (ppv) (11-6) (9I-01) (O€-¥2) (CG-1S) (pS-8p) gE =U
ELE Z Or 9O'TE c'19 € Or 7 O01 6'€I 0°97 8°7S 61S 12jauda] “Y
(S€-L¢) (Zt-0r) (p€-0¢) (Z78-€9) (St-Zp) (ZI-I1) (€I-I11) (E=L0) (€S-6p) (LS-+S) Sl =u
9'LE O'IP E1E 1°69 8°TP OPT Sil 162 €e1s Is¢ uoassysopids *y
(9€-S¢) (6€-8¢€) (9€-62) (Z8-IL) (Ze-I>) I-11) (9I-€1) (ZE=L2) (€S-8p) (09-€¢) wl =u
9°SE 9°8€ 8°ZE €°9L 6 €P SIT SEI €'67 60S 19S snivoyd *y
(LE-S¢) (Or-8¢) (S€-0¢) (p8-IL) (Zv-6€) (4) 1) 0) (pI-Z1) (Z€-8Z) (7S-6p) (6S-SS) LI =u
6'SE 6'8E 6'7E 8 PL 1) 7 611 l€l L'O€ 06 L'9S Snipausajul *y
(L€-9¢) (6€-8¢) (9€-¥¢) ($8-6L) (Ip-8¢) (ZI-O1) (pI-€1) (97-SZ) (pS-7s) (ZS-0S) ¢ =u
7 9€ 9°8¢ C'vE p's 8°6€ Lu Gol ¢'Sz ves Ls 401A94q "Y
Or-6€
yen + Ayyensn
(6€-S€) (€r-8¢) (9¢€-0¢) (08-0s) (9r-9¢) (€I-6) (SI-6) (Z€-€7) (LS-Lp) (9S-6r) 7IZ =u
7 9€ €'6€ 8°7E 799 OIP L‘Ol oI C92 AS Gics snuojsouv “py
ovIQOUO A oury [Bi1qI019}U] yideq ysua] yidoq yisuaT] ywsusy] jepnes uIsUQ sa1zad§
[eloje' 7] pesH ynous apounpedg apounpeg peoH [esiog STAT9d
SIUSIAAPW yisguaT] poay fo asvjuaosad yisuaT] pavpunis fo asnjuadsag
pepuno.) osuel oy} WIM “‘aeaul ay) sjuasoidar oindy Jeddn "
ON
\©
‘(UMOYsS JOU ‘saTeds Ie—NoOUNpeduNoIID
= 6Z) ‘soyeos fepnes 0} yeue (gz ‘sayeos snue 0} stAjad (17 ‘soyeos stayed 0} snuyjst (gz
‘sgjeos [epned 0} assodipe (¢Z ‘sojeos asodipe 0} [esiop (pz ‘sayeos yessopaid (¢Z ‘sayeos
ISIOASUBIT] [EIUDA (ZZ ‘SOTBOS VSIOASULI) [ESIOP ([Z ‘Saeds suT]-[e19}e| (OZ ‘feWUquorajut Auog (6]
‘rajoweIp a49 (g] ‘(uMOYS jou ‘yIpIm Apogq = 1) ‘yIdep ynous (g] ‘yIdap sposadoaid (c]
‘ydap peoy (pt ‘yidep sjounped jepnes (¢] ‘yidep Apog (Z] ‘yISuUs] ynous ({][ ‘YyIBUaT 929
-lodoaid (Q] ‘ysue] pesy (6 ‘yISUs| ofoUNped [epneod (g ‘UISIIO UIJ-asOdIpe 0) UIZIIO UIJ-[esIOp (7
‘UISLIO UIJ-[BPNS 0} UISLIO UTJ-[eSIOP (9 ‘UISLIO UTJ-dTATad 0} MeL IOMOT (¢ ‘UTZIIO UTJ-TesIOp 0} Mel
JaMO] (p ‘UISIIO UTJ-asodipe 0} mef IoMO] (E ‘UTSLIO UlJ-feUe 0} Mel JaMOT (Z ‘YIZUIT PIepUeIS (|
‘(suly yeroj}ood oy) Je poinseow) yIpIM Apoqg pue juNOd [eos Je_NOUNpaduINoIID are UMOYS
JON “SuUNOS puk SULINSeSU JO SpOYISW MOYS 0} DUTUIO)SOUR [RdTIOYyIOdAY & JO MOIA [eIO}e] IO]
| ‘314
70
“UBSU JO APIs JOYITA UO UOTVIAOP plepueys DUO sjudsaidal vare IeayO snjd you|q pue
USUI JO APIS JOYII9 UO JOIIO PIepur}s UO SI vale yoRTG ‘URW stenba sfsueIN yor|Q [Jews ‘osuel
sjenba ouljaseg “SsplooesJeyd SUTUIOJSOUR JO SJUNOD o[edS DUT]-[e19}e] OY) JO WeIZeIP sqqnH-sqqny Z ‘314
sayeos aul] [e1ojeT]
LV Sv tv Iv 6 Le
snjojn3suis ‘S$ oe
snjdadsad *§ V
SnJDINIDUILA] ‘dq ale Sa = |
|
apuldl ‘dq ee
sytaD13 “dq i
suapiq ‘D — v
12Jaula] *W Ser See. cs %
uosij2ojids "Vv Sale a? | Se
snjooiyd *y oT aes
snipauiajui ‘yy | ————______1——
1O1AAIG "YW
SNUOjJSOUD ‘YW
1
: eo
z N =
=| N iS
fo) a
i fo) S =
op & o S
a oD S 2
2 N =
=I Y S
e ie]
: | ¢ ee
XS. <a .
& Si, 625 (ove) BS
c= SO de = fe)
— ke BS) Sam
a \@ a S r=
4 X".0 =< 4. J &
& Sas \O us)
= \ ey — o
Os “oO —
6 ios Ow 2 6UOUDD
é Seo + oe 2
N SN ne a (S| a &
La) e a 1, Oo > a
No) ‘
s T. So 82
— PI —_
S$ Ce x 2 S 2 ne, &
N (JN oO.
~ Oi em x : S = oe)
5 aes aoe esas
“XN Ore no}
IS Sees g 3 = sy s
a S aoe © —
: ee ee ae
a) SS : © S ) &
= 2 (c) WOO O CO | s
S \ ez =| 2
8 » He 2-0
: . = Ie gS
Ge ‘“ “ho oD
fe) N o 2
s XN (=|
Vy N = 9
ts oO ‘ — [ov
a? ‘NS aad
e 6 = 2s
oe us tas
io} fe}
= g 5
qs 5 <
: Se a ce :
: (oo oOo MN 5 - :
2 ee Se eee ee cee eno kee a le
LL, ea ™
yidop sjounpeg
45.00
40.00
_A. brevior R’ = 0.95 (@)
30.00 ae ‘A. anostomus R? = 0.90 (X)
A. ternetzi R? = 0.95
10.00
15.00 20.00 25.00 30.00 35.00
Head length
Fig. 5 Graph showing regression lines of head length vs body depth for Anostomus anostomus (points
plotted), A. brevior (points plotted), and A. ternetzi.
aS
18.00
Head depth
N
S
=
15.00 20.00 25.00
Head length
A. anostomus R? = 0.93
A. brevior R? = 0.88 (X)
A. ternetzi R*? = 0.96 (0)
30.00
35.00
Fig. 6 Graph showing regression lines of head length vs head depth for Anostomus anostomus, A. brevior
74
(points plotted), and A. ternetzi (points plotted).
—
| <a -*
WY
5S mm 5S mm 5mm
Fig. 7 Anostomine scales (taken from right side of body, below the dorsal fin origin, representing the
scale row above the lateral line (upper) and the lateral line (lower)).
A. Anostomus anostomus, aquarium specimen, 78.0 mm SL.
B. Pseudanos gracilis, SU 16280, 91.3 mm SL.
Cc. P. irinae, SU 16281, 66.2 mm SL.
D. A. plicatus, AMNH 17602, 73.5 mm SL, lateral-line scale only.
E. Synaptolaemus cingulatus, MBUVC V-4252, 71.2 mm SL.
75
‘(snyojnsuis
snuavjoidoucs pure snjoadsaa 401405 ‘suapig snjopoyiwuy) e1aue3 auTWO\souR d1dAjouOW sary) oy}
Pure (12/au1a) “pf pue 40]A041g “py ‘snwojsoun ‘y) saiseds snwojsoup padins ay) Jo dew uonnqmsiq g ‘314
SU1JUDIOT[
widoy
snjpjn3uia ‘Ss
snjoadsai‘S @
suapiq ‘D 6
12]9U13] "VY @
401001 °P A
snwiojsoun "py &
Fz ry
DilapDN
solodv | snin
= uozoup \ !21n¢
pando
3
OouDig pa at
aivinbisva
6Vve
Se
DpvyrIA
youninp
pjanboD a
.
pn3svi0d
oqinbassq ae
76
Anostomus anostomus
ZMA 106.528
10.00
x
x
9.0 :
Ms ZMA 106.529
“A (@)
8.0 : *
a=40): R? = 0.95 .
x= R? = 0.98
= 90 4 = immature e e
iy @
a]
a e
2
3 6.0 4 s
A,
5.0
&
4.5
45 50 55 60 65 70 Ws) 80 85 90
Standard length
Fig. 9 Graph of standard length vs peduncle depth for Anostomus anostomus (ZMA 106.528, 25, and ZMA
106.529, 1). R? calculated for males and for females plus juveniles.
Fig. 10 Left lateral view of Anostomus brevior (MNHN 01-407, 72.6 mm SL, paratype). Fins artificially
figured as though spread, only lateral line scales shown.
17
Left lateral view of Anostomus intermedius sp. nov. (SMF13618, 77.7 mm SL, holotype). Fins
artificially figured as though spread.
Bigelt
A. spiloclistron R? = 0.98 (0
A. plicatus R? = 0.97(h)
30.00 35.00
5.00
2
Head length
20.00
A. intermedius R? = 0.99 (x)
15.00
Senses <= oa WS =
ysus] NOUS
12 Graph showing regression lines and points of head length vs snout length for Anostomus
Fig.
intermedius, A. plicatus, and A. spiloclistron.
78
LV
OV
SY
vv
Y1sUs] pesy JO a3eJUSdJEd se YISUI] NOUS
Iv
ep
‘uoasyoojids ‘py pue snivoid ‘py
‘snIpausajul SNWOISOUP IO} YIBUI] peoy Jo a3eJUIdIEd se YISUD| INOUS Jo WeIZeIP sqqny-sqqny =¢{ “34
(44
SNIpaULlajul * py
OV 6£
|
snjooyd ‘py
uoMsSyIojids *y
|
8E
79
‘SnIDjnNIDUIA] ‘qd pue ‘aDUIAI ‘d
‘syop48 souppnasd ‘uousyoopids ‘py ‘snivoyd “py ‘snipausajul snwojsouy Joy dew uonnqmsiq fl ‘34
a1odony
Dilapow
i
suluvnoo
ILLAHIINN oqinbassq
snjpjnovuld] ‘qd ¥
avulll ‘q @
siiop48 ‘d A
uomsyoojids ‘vy @
snjooyd VE
Gp SMipauiajul “y 5) ¢
OJ0ULIC
80
Fig. 15 Left lateral view of Anostomus plicatus (composite). Fins artificially figured as though spread,
only lateral-line scales shown.
Fig. 16 Left lateral view of Anostomus spiloclistron (ZMA 112.685, 77.2 mm SL, holotype). Fins
artificially figured as though spread (from Winterbottom, 1974a).
Fig. 17 Left lateral view of Anostomus ternetzi (MZUSP 9990, 80.0 mm SL). Fins artificially figured as
though spread, only lateral-line scales shown.
81
Fig. 18 Left lateral view of Gnathodolus bidens (CAS 20087, 108.8 mm SL, holotype). Fins artificially
figured as though spread, only lateral-line scales shown.
Ce
5 mm
eS Se
Fig. 19 Gnathodolus sp. (BM(NH) 1972-12-5:5, 51.5 mm SL). Left lateral view of snout to show lower
jaw tooth and papillae of the lower lip.
82
2cm
Fig. 20 Left lateral view of Pseudanos gracilis (composite). Fins artificially figured as though spread,
only lateral-line scales shown.
A The striped form.
B The spotted form.
71.8 mm SL, paratype). Fins
L
20097
Left lateral view of Pseudanos irinae sp. nov. (CAS
artificially figured as though spread.
Fig. 21
83
Body width
15.00 20.00 25.00 30.00 35.00
Head length
Fig. 22 Graph showing regression lines and points of head length vs body width for Pseudanos irinae and
P. trimaculatus.
84
Eye diameter
15.00 20.00 25.00 30.00 35.00
Head length
Fig. 23 Graph showing regression lines of head length vs eye diameter for Pseudanos irinae (points
plotted) and the four populations of P. trimaculatus (Eastern Amazon, Ecuador, Mato
Grosso—points plotted—and Peru).
85
Fig. 24 Left lateral view of Pseudanos trimaculatus (composite). Fins artificially figured as though
spread, only lateral-line scales shown.
80.00
Ecuador R? = 0.99 (7) aS
Mato Grosso R? = 0.99 (X)
75.00
70.00
65.00
60.00
55.00
50.00
45.00
Pelvic origin
S
S
S
30.00
25.00
20.00
40 50 60 70 80 90100 110 120130 140 150 160
Standard length
Fig. 25 Graph showing regression lines and points of standard length vs lower jaw to pelvic origin for
Pseudanos trimaculatus populations from Eastern Amazon, Ecuador, Mato Grosso and Peru.
86
Body depth
x
45.00 Mato Grosso R* = 0.90 (X) 7.
Ecuador R? = 0.98 (V7) he va
40.00 fe A
“a Lo
Peru R? = 0.95 (0) Ya
35.00 Ea eae
30.00
15.00 20.00 25.00 30.00 35.00
Head length
Fig. 26 Graph showing regression lines and points of head length vs body depth for Pseudanos
trimaculatus populations from Eastern Amazon, Ecuador, Mato Grosso and Peru.
87
‘Tdg pur ‘OSsOIH oe] ‘JOpendg ‘uozewY Wo}seq Wo suone[ndod snjojnovwi4 sounpnasd
JOJ YIBus] prepuLjs Jo o3eJUs.I0d e se YysUd] sJoUNpod [epned Jo WeIseIp sqqny-sqqnyH /Z ‘3I4
YISus] plepue}s Jo o8e}UDNIOd se YASUI] BPOUNpsg
Jopenoq
nlag
TT : 2 uoZeWIW “A
OSSBIL) OSI]
SNJDINIDU1A] SOUDPNIASdT
88
Fig. 28 Left lateral view of Sartor respectus (composite). Fins artificially figured as though spread, only
lateral-line scales shown.
Fig. 29 Left lateral view of Synaptolaemus cingulatus (MBUCV V-4252, 90.0 mm SL). Fin artificially
figured as though spread, only lateral-line scales shown.
infraorbitals 1-6
BVT.
lcm
Fig. 30 Pseudanos trimaculatus, RUSI 5521, 52.1 mm SL. Left lateral view Of the infraorbitals,
antorbital and supraorbital. Inset above: dorsal view of left nasal bone from 86.0 mm SL
specimen from the same collection.
89
#0.
5mm
1 cm
Fig. 31 A Anostomus spiloclistron. Left lateral view of antorbital and infraorbitals 1 and 2.
B Pseudanos gracilis. Left lateral view of infraorbitals 1 and 2.
90
1 cm
supraorbital
antorbital
1 cm €.187.
Fig. 32 A Synaptolaemus cingulatus. Left lateral view of infraorbital, antorbital, and supraorbital bones,
with a dorsal view of the left nasal bone above.
B Gnathodolus sp. Left lateral view of infraorbital, antorbital and supraorbital bones, with a
dorsal view of left nasal bone above (both from mirror images of right side).
91
hyomandibular
premaxilla
opercle
maxilla
palatine
mesopterygoid
metapterygoid
ectopterygoid
dentary
articular subopercle
angular
quadrate preopercle symplectic interopercle
ET.
1 cm
ee
Fig. 33. Pseudanos trimaculatus, RUSI 5521, 86.0 mm SL. Left lateral view of suspensorium and jaws.
opercle
interhyal
metapterygoid
hyomandibular mesopterygoid
palatine
ectopterygoid
subopercle
dentary
sesamoid articular
angular
articular
interopercle symplectic preopercle quadrate
RAT.
1 cm
Fig. 34 Pseudanos trimaculatus, RUSI 5521, 86.0 mm SL. Medial view of left suspensorium and lower
jaw.
92
palatine mesopterygoid metapterygoid symplectic
ecopterygoid hyomandibular
quadrate
interopercle
preopercle
4.7.7.
1 cm
Fig. 35 Pseudanos gracilis. Left lateral view of anterior portion of suspensorium.
metapterygoid
mesopterygoid
hyomandibular
palatine opercle
symplectic
subopercle
ectopterygoid
quadrate interopercle
preopercle
1 cm
eee
Fig. 36 Anostomus plicatus. Left lateral view of suspensorium.
95
1 mm
Fig. 37. Anostomus plicatus. Medial view of left premaxilla.
frontal
pterosphenoid = pterotic
P orbitosphenoid ae
lateral ethmoid
ethmoid “ sphenotic
vomer ~~ - ee
hyomandibular
=S % : parasphenoid
eee tir a) metapterygoid
maxilla Bis, series
dentary ee
s i
ectopterygoid ymp
angular
articular preopercle
palatine = —— |
mesopterygoid
quadrate
lcm
Fig. 38 Anostomus spiloclistron. Left lateral view of anterior region of skull (infraorbitals removed).
94
opercle
hyomandibular
metapterygoid
mesopterygoid
palatine
ectopterygoid
premaxilla preopercle
maxilla
dentary subopercle
articular interopercle
angular
symplectic
quadrate
Fig. 39 Synaptolaemus cingulatus. Left lateral view of suspensorium and jaws.
$
eS
~
s?
dentary
articular
subopercle interopercle preopercle angular
ee &.H.T.
Fig. 40 Synaptolaemus cingulatus. Medial view of left suspensorium and lower jaw.
95
interhyal hyomandibular
symplectic
metapterygoid
mesopterygoid
opercle
palatine
ectopterygoid preopercle
articular
subopercle
interopercle
dentary
angular quadrate
a A
1 cm
ee ——————— ey
Fig. 41. Gnathodolus sp. Left lateral view of suspensorium and lower jaw (mirror image of right side).
ceratohyal branchiostegal rays
dorsal hypohyal
interhyal
ventral hypohyal epihyal
€20-T.
1 cm
Fig. 42 Pseudanos trimaculatus, RUS! 5521, 86.0 mm SL. Left lateral view of hyoid arch and
branchiostegal rays.
96
branchiostegal rays
epihyal
ceratohyal
dorsal hypohyal
Sr eitesavelneie
ventral hypohyal
£00. T.
1 mm
a
Fig. 43 Pseudanos trimaculatus, RUS! 5521, 52.1 mm SL. Medial view of left hyoid arch and
branchiostegal rays.
B.A8T.
Fig. 44 Urohyal of Pseudanos trimaculatus, RUS| 5521, 86.0 mm SL.
A Left lateral view.
B Ventral view.
C RuSI 5521, 52.1 mm SL, left lateral view.
97
toothplate fused to basibranchial 2?
basibranchials 2 & 3
basihyal toothplate basihyal
toothplate fused to basibranchial 2?
basibranchial 1 basibranchials 2 & 3
Smm
ee ———————————————————————
er oe Oe
Fig.45 A Pseudanos irinae, CAS 20097, 74.0 mm SL. Left lateral view of basihyal and basibranchials.
B P. trimaculatus, RUS! 5521, 86.0 mm SL. As above.
98
dorsal hypohyal
epihyal ay ypohy
ventral hypohyal
ceratohyal
branchiostegal rays
-2.1¢.T.
5 mm
CIRC.
5mm
SS |
Fig. 46 Anostomus spiloclistron.
A Medial view of left hyoid arch and branchiostegal rays.
B_ Left lateral view of urohyal.
99
interhyal
epihyal
ceratohyal
dorsal hypohyal
ventral hypohyal
branchiostegal rays
1 cm
Fig. 47. Synaptolaemus cingulatus. Medial view of left hyoid arch and branchiostegal rays, with a left
lateral view of the urohyal (above, left).
ceratobranchials 1-5
hypobranchials 1-3
basihyal toothplate
basibranchials
1 cm 1 mm
bn ba
Fig. 48 Pseudanos trimaculatus, RUS! 5521, 86.0 mm SL. Dorsal view of ventral elements of branchial
arches. Inset right: Left lateral view of two teeth from the fifth ceratobranchial toothplate.
100
infrapharyngobranchials 1-3 epibranchials 1-4
4th & Sth upper pharyngeal toothplate cartilaginous infrapharyngobranchial 4
é
°
3
tT.
Fig. 49 Pseudanos trimaculatus, RUSI 5521, 86.0 mm SL.
A Ventral view of dorsal elements of branchial arches.
B Dorsal view of dorsal elements of branchial arches.
A
? i i =
Ganihyaltoothplate ?toothplate fused to basibranchials 1-2
basihyal basibranchials 1-3
1 cm
ceratobranchials 1-5
B
hypobranchials 1-3
basihyal
basihyal toothplate
basibranchials 1-3
RAT.
Fig. 50 Synaptolaemus cingulatus.
A Left lateral view of the median elements of the hyoid and branchial arches.
B Dorsal view of the median elements of the hyoid arch and the ventral elements of the branchial
arches.
101
‘snyeredde
UBLIDQIAA PUB LUNTURIO JO MAIIA [eIDIV] YOT “TS WU Q'9g ‘1ZS¢ ISNU ‘snIDjnNODWUI4] SOUDpNasg [¢ ‘314
LH? Wd |
[eudiosoiseq ey ed19}UI 91001d prousydseied
Z WINIJUSD JO ssad01d [e19}e] IQUIOA
MNnIe[ e193} Ul
qui [einod
sndiq}
PIOWY}9 [e19}eT
[ [einoutds
uInIysneyd Ns prowiy}e
umnrydeds ° 3
prousydso}iqio
jeqwoly
xa|duio9 jenou \ a a
[eqd1s90xa o10usyds
jeydiso0esdns o1j0193d
Bssoj [e10dui9}}sod
on01da yeyorsed
102
‘poaowias untydesg ‘snjeredde
IZS¢ ISNU ‘SNIDJNIDUA] SOUDPpNasd 4s ‘S14
‘
URLIOGaA, PUR UINTURIO JO MAIA [RNUZA “TS WW ~'9g
ae Wid |
LHe
USUIBIOJ [PINVJ-OUTWIDSII} plousydseied eqwoly
UdUIeIOJ [eR]
Bssoj [e1odulajqns
uswWIeIOJ AIOVIpNe
UdUIVIOFJ SNSBA
ansdeo 1eusse]
wimnriosuedsns so
prlowyje
sndiq}
qui jeinoyd batt
WINLIeyed19}UI
PIOUIY}9 [e19}e]
¢ WINI}U99 JO ssad01d [e19}e]
ea : do prousydsojiqio
01
Teyeo19,UI prousydso1aj3d
o11019}d d130uNyYds 911001d
UsWIeIOJ PIOIeS
103
vomer
ethmoi
lateral ethmoi
frontal
cranial fontanel
sphenotic
parietal
pterotic
posttemporal
fossa
kT.
ital
supraoccipi
1 cm
ital
exoccipi
ium.
f cran
1e¢w O
Fig. 53 Pseudanos trimaculatus, RUS! 5521, 86.0 mm SL. Dorsal v
104
supraoccipital
posttemporal fossa parietal
epiotic
pterotic
foramen magnum
intercalar
exoccipital
basioccipital
parasphenoid
Byer.
i cm
Fig. 54 Pseudanos trimaculatus, RUS! 5521, 52.1 mm SL. Posterior view of cranium.
105
orbitosphenoid pterosphenoid
5mm
|
Fig. 55 Pseudanos trimaculatus, RUS! 5521. Left lateral view of orbit to show foramen in parasphenoid.
A 52:1 mmeSE,
B 67.6 mm SL.
LO EEeEeEeEeEeEeEeEeeEeEes
& 27.
Fig. 56 Anostomus anostomus, RUSI 5522, 74.0 mm SL. Dorsal view of posterior region of skull.
106
pterosphenoid frontal sphenotic parietal supraoccipital
orbitosphenoid
ethmoid
epiotic
lateral ethmoid
vomer exoccipital
pterotic
intercalar
basioccipital
A prootic
parasphenoid
Fig. 57 Synaptolaemus cingulatus. Left lateral view of cranium.
sphenotic pterotic
pterosphenoid parietal
frontal supraoccipital
orbitosphenoid epiotic
lateral ethmoid e
Weberian apparatus
oe pp
ethmoid
exoccipital
intercalar
vomer
basioccipital
prootic
parasphenoid
1 cm 4rtT
Fig. 58 Gnathodolus sp. Left lateral view of cranium (mirror image of right side). Anterodorsal portion
of suspensorium (see Fig. 41) in dashed outline to show its articulation point with the vomer.
107
ethmoid pterosphenoid frontal sphenotic
lateral ethmoid
parietal
vomer supraoccipital
pterotic
intercalar
exoccipital
basioccipital
orbitosphenoid prootic
parasphenoid
1 cm
Fig. 59 Sartor respectus. Left lateral view of cranium.
neural complex
claustrum
; neural pedicle (v3)
scaphium
. . neural arch & spine (v4)
intercalarium
rocess (v3
centrum 2 transverse process (v3)
centrum | centrum 4
transverse process (v2) ;
pleural rib (v4)
tripus
Fig. 60 Synaptolaemus cingulatus. Left lateral view of Weberian apparatus.
108
posttemporal
extrascapular
supracleithrum
postcleithra 1-3
cleithrum
scapula
coracoid
proximal radials
Rit T.
1 cm
Fig. 61 Pseudanos trimaculatus, RUS! 5521, 86.0 mm SL. Lateral view of left pectoral girdle.
extrascapular
posttemporal
supracleithrum
cleithrum
mesocoracoid
postcleithra 1-3
scapula
distal radial (ray 1)
coracoid
proximal radials
lcm 2.10.7.
Fig. 62 Pseudanos trimaculatus, RUS| 5521, 86.0 mm SL. Medial view of left pectoral girdle.
109
pelvic bone
ischial process
_ —_—— radial elements
€.€T.
1 cm
Fig. 63 Pseudanos trimaculatus, RUS! 5521, 86.0 mm SL. Ventral view of pelvic girdle and fins.
radial elements
fin rays
ischial process
pelvic bone
ttt
1 cm
Fig. 64 Pseudanos trimaculatus, RUS! 5521, 86.0 mm SL. Dorsal view of pelvic girdle and fins.
110
distal pterygiophores
medial pterygiophores
neural spines
€ 0.
1 cm
Fig. 65 Pseudanos trimaculatus, RUS| 5521, 86.0 mm SL. Left lateral view of dorsal fin and supporting
elements.
haemal spines
medial pterygiophores
distal pterygiophores
anal stay
proximal
pterygiophores
fin rays
“CNT.
1 cm
Fig. 66 Pseudanos trimaculatus, RUS! 5521, 86.0 mm SL. Left lateral view of anal fin and supporting
elements.
111
uroneurals 1-2
epurals 1-3
modified neural process
urostyle
neural spines - x
complex ural centrum
hypurals 1-6
haemal spines
parhypural
1 cm
Fig. 67 Pseudanos trimaculatus, RUS! 5521, 86.0 mm SL. Left lateral view of caudal skeleton.
7)
7) = = 7)
x aS) S 3 a
~ iw ~— os
3 4 = 4 3 9 ~ =
x e SS = x = N 5 S
o 2 d 1S = o S > AS) =
S} & os as} 3) 3 S) L & > a
iS} 5 — Ke iS) = Y = i=)
— om ~ PY ~— Q ~ oO N r
x re ~ n S Q a = ~ XS 8
Ka a S 3S a 8 3 S 3 3 = 3
= = = 3 2 iS = S = = S =
3 iS} 8 S) = S S S S S S
3 = aS = S & 3 3 3 3 3 3
= = = 8 > S} S S) S S S S
2 2 BY = ~ = = =
7) 7) w it~ iS} EN & twa r
Q Q Q 1) Y n x SS x SE x x
2? 4 6 7
Fig. 68 Hypothesized phylogeny of the Anostominae. Numbers at the base of each dichotomy refer to the
branch points so numbered in the Discussion section of this paper.
BZ
+ Ap; y oe 5 oe ~ *.9 ~ .
vty ee he a Ae | i ue 5
p ay Rae A Vez Pap » » 7 4) bet : Ds me
+ Fo Nil i, d Sie x an Aa oh ee ee i ee - S-
“ah mn is, mie ‘gts ‘ ah Pe , i
. ty. 2 =, f % a my) * - <
' F r : . _ Ea
RE Dole Wie 7
ye nS ta)
«
i "
4 f 4 ~
: =
- as ‘.
*
a “3
\ ~
*
ae
4 :
4
4
‘
‘ " <
* > ‘
»
A MA ~
e * é ‘
- . yy
(me , , «
,
e *
\ . . ° iv, *
4 \ ’
P
é
, F i j
. \ ' 1
. a
ISBN 0-88854-252-6
ISSN 0384-8159
Live Music Archive
Librivox Free Audio
Metropolitan Museum
Cleveland Museum of Art
Internet Arcade
Console Living Room
Books to Borrow
Open Library
TV News
Understanding 9/11