Diversity and distribution of anostomoid fishes  
(Teleostei: Characiformes) throughout the Guianas**
by
Brian L. SidLauSkaS* (1, 2) & Richard P. VaRi (2)
AbstrAct. - Fifty-six species or approximately 20% of the Neotropical characiform superfamily anostomoidea (fami-
lies anostomidae, Chilodontidae, Curimatidae and Prochilodontidae) occur in the freshwaters of French Guiana, Guyana, 
and Suriname although these regions span only approximately 6% of the native range of this morphologically and ecologi-
cally diverse superfamily. as a result of the high diversity of anostomoids in the Guianas, the taxonomic and/or geographic 
boundaries of many species are poorly understood, particularly within the family anostomidae. This contribution unites 
results of prior taxonomic revisions with surveys of the holdings of the superfamily in seven major natural history collec-
tions to provide distribution maps and keys to the identification of all anostomoid species known to occur in the Guianas. 
These maps reveal six major areas of endemism: the Takutu and ireng rivers (Rio Branco drainage, amazon basin), the 
Barima and Waini rivers (Orinoco drainage), the Essequibo-Rupununi River system (including the demerara and Berbice 
rivers), a union of the Corantijn, Nickerie, Coppename, Saramacca and Suriname river drainages, the Marowijne/Maroni 
River system (including the Litani and Mana rivers), and the Oyapock-approuague River basins. Of these, the Essequibo-
Rupununi system harbours the most exceptionally diverse assemblage of anostomoid species, likely as a result of faunal 
exchange between the Rio Branco and Essequibo River across the Rupununi portal. 
r?sUM?. - diversit? et distribution des poissons anostomoides (Teleostei, Characiformes) dans les Guyanes.
Cinquante-six esp?ces, soit approximativement 20% des Characiformes de la superfamille des anostomidea (familles 
des anostomidae, Chilodontidae, Curimatidae et Prochilodontidae), fr?quentent les eaux douces de la Guyane fran?aise, du 
Guyana et du Suriname bien que ces r?gions ne recouvrent qu?environ 6% de la distribution naturelle de cette superfamille 
morphologiquement et ?cologiquement tr?s diverse. ?tant donn?e cette grande diversit? des anostomoides guyanais, les 
limites taxonomiques et/ou g?ographiques de nombreuses esp?ces sont mal d?finies, particuli?rement dans la famille des 
anostomidae. Ce travail combine les r?sultats de r?visions taxonomiques ant?rieures ? l??tude de sept collections majeures 
d?histoire naturelle afin de fournir des cartes de distribution et des cl?s d?identification de toutes les esp?ces d?anostomoi-
des connues des Guyanes. Ces cartes r?v?lent six aires d?end?misme principales : les rivi?res Takutu et ireng (bassin du 
Rio Branco, syst?me de l?amazone), Barima et Waini (bassin de l?Or?noque), le syst?me Essequibo-Rupununi (incluant 
le Demerara et le Berbice), les bassins des fleuves Corantijn, Nickerie, Coppename, Saramacca et Suriname, le syst?me 
Marowijne/Maroni (incluant la Litani et la Mana), et les bassins de l?Oyapock et de l?approuague. Parmi ces six aires d?en-
d?misme, le syst?me Essequibo-Rupununi h?berge un ensemble d?esp?ces exceptionnellement diversifi?, r?sultant vrai-
semblablement d??changes d?ichtyofaune entre le Rio Branco et l?Essequibo via le portail du Rupununi.
key words. - Biogeography - dichotomous key - Georeferencing - South america - Synthesis - Taxonomy.
Cybium 2012, 36(1): 71-103.
** Supporting files are available online: http://www.mnhn.fr/sfi/cybium/numeros/361/sommaire361.html
(1) Oregon State University, Department of Fisheries and Wildlife, 104 Nash Hall, Corvallis, OR 97331-3803, USA.
(2) Department of Vertebrate Zoology, MRC-159, National Museum of Natural History, PO Box 37012, Smithsonian Institution, 
Washington, DC 20013-7012, USA. [varir@si.edu]
* Corresponding author [brian.sidlauskas@oregonstate.edu]
The Neotropical characiform superfamily anostomoidea 
contains approximately 275 recognized species (Reis et al., 
2003, plus species described subsequently). These ecologi-
cally and morphologically diverse species range from the 
often large-sized and economically important detritivores of 
the families Prochilodontidae and Curimatidae that play crit-
ical roles in nutrient cycling in many river systems (Taylor et 
al., 2006), to the omnivorous and herbivorous headstanders 
of the anostomidae and Chilodontidae. Though anostomoids 
clearly form a natural group (Vari, 1983) and are among the 
best-studied members of the Characiformes, their alpha, 
beta and gamma diversity remains incompletely understood. 
descriptions of new anostomoid species still appear regu-
larly (Britski and Garavello, 2005; Vari and Chang, 2006; 
Scharcansky and Lucena, 2007; Sidlauskas et al., 2007; 
Britski and Birindelli, 2008; Santos and Zuanon, 2008; Bir-
indelli and Britski, 2009; Vari et al., 2012). The taxonomic 
limits and geographic distributions of some long-recognized 
species frequently remain hazy, particularly within the fam-
ily anostomidae, which has never been the subject of a com-
prehensive revision. 
The north-flowing drainages of the portions of the 
Guiana Shield in French Guiana, Guyana and Suriname 
(hereafter the Guianas) along with the Takutu and ireng 
rivers which form the northeastern portion of the upper 
Rio Branco basin in southern Guyana (Fig. 1) comprise a 
Anostomoid diversity in the Guianas  SidlauSkaS & Vari
72 Cybium 2012, 36(1)
major area of diversity and endemism for many groups of 
Neotropical freshwater fishes, including anostomoids. The 
discovery of the exceptional biodiversity of anostomoids 
in the Guianas commenced with the earliest surveys of the 
region in the 18th century. Species now recognized as Anos-
tomus anostomus (Linnaeus, 1758), Leporinus fasciatus 
(Bloch, 1794) and L. friderici (Bloch, 1794) were described 
from localities likely or definitely in Suriname. A continu-
ing stream of descriptions of anostomoid species from the 
Guianas by M?ller and Troschel, Cuvier and Valenciennes, 
Steindachner, Eigenmann, Fowler and more recent authors 
ensued. Continuing surveys in the region regularly reveal 
new species (Sidlauskas et al., 2011; Vari et al., 2012) 
although longstanding taxonomic confusion stemming from 
the imprecise nature of many earlier descriptions hampers 
formal systematic or faunistic work. Ready identification 
and understanding of the biodiversity of anostomoids, most 
notably anostomids, in the Guianas is impeded by myriad 
factors including brief original species descriptions, com-
plex or lost type series, a proliferation of potential junior 
synonyms discriminated on less than trenchant differences, 
and indefinite geographic distributions. Further complica-
tions include the historic application of some of the earliest 
species names to complexes of externally similar forms with 
distributions spanning huge swaths of South america (e.g., 
Leporinus friderici), the co-occurrence of many superficially 
similar species, and a confounding tendency of species in the 
anostomidae to undergo major ontogenetic shifts in colour 
pattern and sometimes mouth position (Santos, 1980; Sid-
lauskas et al., 2007; Birindelli and Britski, 2009).
This contribution aims to ameliorate the confusion sur-
rounding the taxonomy and biogeography of anostomoids in 
the Guianas by synthesizing the extant systematic literature 
with new surveys, reidentifications and georeferencing of 
specimens from this region in several natural history collec-
tions. Our effort represents an attempt to:
1) sort the anostomoid diversity in the Guianas into dis-
tinct morphospecies;
2) illustrate the geographic range of each morphospe-
cies;
3) provide dichotomous keys specific to the anostomoid 
morphospecies in the Guianas; and
4) determine the extent to which the various river sys-
tems of the Guianas harbour endemic faunas. 
in the Chilodontidae, Curimatidae, and Prochilodontidae, 
these efforts derive from comprehensive revisionary studies 
(Vari, 1982; Isbr?cker and Nijssen, 1988; Vari, 1989a; Vari, 
1989b; Vari, 1989c; Vari, 1989d; Vari, 1991; Vari, 1992a; 
Vari, 1992b; Vari et al., 1995; Castro and Vari, 2004) and 
subsequent publications. Neither an encompassing revision 
nor modern comprehensive keys for the anostomidae exist. 
For the purposes of this contribution, individuals within the 
anostomidae were sorted into recognizable morphospecies 
and then identified through reference to the primary taxo-
nomic literature, including original species descriptions and 
generic and regional taxonomic revisions. This contribution 
does not constitute a formal revision of all members of the 
anostomidae across the Guianas, which for certain species-
complexes would require the critical analysis of extensive 
series of samples originating from vast portions of tropical 
South america. The results, nonetheless, highlight many 
range extensions, identify several likely junior synonyms 
Figure 1. - Major river systems of the 
Guianas. Stream network prepared by 
the Nature Conservancy from a digital 
elevation model. 
SidlauSkaS & Vari Anostomoid diversity in the Guianas
Cybium 2012, 36(1) 73
and reveal the existence of morphoclines or multiple recog-
nizable entities within certain nominal species. We discuss 
these taxonomic issues herein, but leave the formal syno-
nymization of described forms and description of potentially 
new species to future revisionary efforts. 
MAteriAls And Methods
We examined and compiled information on 1,272 lots 
representing nearly-complete anostomoid holdings of four 
natural history collections with major holdings from Guy-
ana and Suriname (american Museum of Natural History, 
aMNH; academy of Natural Sciences of Philadelphia, 
aNSP; auburn university ichthyology Collection, auM; 
and the National Museum of Natural History, uSNM) as 
well as partial holdings from three institutions (Field Muse-
um, FMNH; Mus?um d?Histoire Naturelle de la Ville de 
Gen?ve, MHNG; and Nationaal Natuurhistorisch Museum 
Naturalis, RMNH). a spreadsheet containing museum cata-
logue numbers, vouchered identifications and geographic 
coordinates for these 1,272 lots is available as an online 
supplement. individuals of the Chilodontidae, Curimatidae 
and Prochilodontidae were identified using keys from recent 
taxonomic revisions, updated where appropriate to reflect 
subsequent species descriptions and additional data on mor-
phological variation. Material from French Guiana was far 
less common in the collections of these seven institutions, 
but time constraints prevented visits to collections housing 
more extensive holdings of material from that department. 
Largely offsetting that impediment is the information on 
the occurrence and distribution of freshwater fish species of 
French Guiana in the excellent accounts by Planquette et al. 
(1996), and identifications of additional material from that 
department at MHNG by Sonia Fisch-Muller and Rapha?l 
Covain based upon the keys presented herein. We included 
1,561 records from the Planquette et al. (1996) accounts and 
updated their identifications to reflect subsequent pertinent 
revisionary efforts (e.g., Prochilodus in the Prochilodonti-
dae, Castro & Vari, 2004), resulting in a total of 2,833 lots 
that underlie this study. 
The dichotomous keys for the Chilodontidae, Curimati-
dae and Prochilodontidae presented herein draw upon previ-
ously published keys (Vari, 1989c; Vari, 1991; Vari, 1992a; 
Vari, 1992b; Vari et al., 1995; Castro and Vari, 2004) upda-
ted where appropriate to reflect subsequent publications 
(e.g., Vari et al., 2012) and revised to clarify certain ambi-
guities or to more accurately capture and focus on breaks 
in morphometrics, pigmentation or meristics observed in 
anostomoids from Guyana, Suriname, and to a more limited 
extent, French Guiana. a portion of the key to the anosto-
midae extracts couplets from earlier efforts (Winterbottom, 
1980; Planquette et al., 1996; Sidlauskas and Santos, 2005) 
supplemented by data from recent species descriptions (Sid-
lauskas et al., 2011). Much of the key to that family is, how-
ever, based on new measurements and observations of speci-
mens from Guyana and Suriname. The keys are intended for 
use only with samples from the targeted geographic area and 
will not necessarily diagnose individuals from outside the 
Guianas to the correct genus, let alone species. 
Because members of the anostomidae exhibit an extreme 
range in mouth orientation, we follow Winterbottom (1980) 
and take standard length from the anteriormost point of the 
head (which in species with upturned mouths is not always 
the anterior margin of the snout) to the posterior margin of 
the hypurals. Postorbital length and head length are mea-
sured to the posteriormost bony margin of the opercle. 
Orbital diameter is difficult to measure in some curimatids 
because of the presence of an adipose eyelid, but is taken 
from the anterior margin of the orbit at the ventral wing of 
the lateral ethmoid to the posterior margin of the orbit. Gape 
width is the distance measured between the opposite limits 
of the mouth. Vertebral counts include the four vertebrae of 
the Weberian apparatus and the composite terminal centrum 
(counted as a single unit).
The distribution maps represent a combination of lots 
of material that we examined from aMNH, aNSP, auM, 
FMNH, MHNG, RMNH and uSNM and published lists of 
examined material that we consider to be reliably identified 
and georeferenced. Material in that latter category includes 
type series and specimens cited in recent formal taxonomic 
revisions, such as the extensive series of specimens of the 
Guianas deposited in various institutions that was examined 
in revisions of the genera of the Chilodontidae (isbr?cker 
and Nijssen, 1988; Vari et al., 1995), Curimatidae (Vari, 
1982; Vari, 1989b; Vari, 1989c; Vari, 1991; Vari, 1992a; Vari, 
Figure 2. - Total extent of collection localities represented among 
included specimen lots.
Anostomoid diversity in the Guianas  SidlauSkaS & Vari
74 Cybium 2012, 36(1)
1992b) and Prochilodontidae (Castro and Vari, 2004). Where 
possible, lots lacking explicit latitude and longitude infor-
mation were assigned coordinates by reference to gazetteers, 
maps, publications, and online sources. in total, 2667 lots of 
material were assigned to point localities spanning much, but 
not all of Guyana, Suriname and French Guiana (Fig. 2). The 
166 examined lots with ambiguous localities (e.g., Suriname 
or Guiana Highlands) were not plotted. Maps were prepared 
in ArcMap 9.3 (Environmental Systems Resource Institute, 
2008) using an underlying river network based on a digital 
elevation model that was made available by Paulo Petry of 
The Nature Conservancy. Every point on these distribution 
maps is tied to a specific specimen lot, which are listed in 
the online appendix with the exception of data previously 
published in Planquette et al. (1996) and kindly provided for 
reproduction in this article by dr. Philippe keith (Mus?um 
national d?Histoire naturelle, Paris). Copyright to those data 
remains with iNRa-MNHN. Most photographs were pre-
pared using the phototank immersion method of Sabaj P?rez 
(2009)
resUlts 
Key to families of Anostomoidea in Guyana, Suriname 
and French Guiana
1a: Jaws with well-developed teeth firmly implanted in 
upper and lower jaws. . . . . . . . . . . . . . . . . . . . Anostomidae
1b: Jaws either lacking dentition in adults or teeth movably 
attached to fleshy lips  . . . . . . . . . . . . . . . . . . . . . . . . . . . . (2)
2a: Jaws lacking any teeth other than in larvae; lips thin  . . .  
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . curimatidae
2b: dentition present on at least upper jaw, although some-
times reduced; lips or at least upper lip variably fleshy . . . (3)
3a: Jaws evertible into suctorial disk; oral teeth numerous 
with multiple rows of replacement teeth arranged in linear 
series extending towards oral cavity; teeth spatulate. . . . . . . 
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  Prochilodontidae
3b: Jaws not evertible; oral teeth sparse and limited to single 
functional row, sometimes limited to upper jaw; teeth typi-
cally conical, rarely bicuspid . . . . . . . . . . . . . Chilodontidae
Key to Anostomidae from Guyana, Suriname and 
French Guiana
1a: Caudal-fin rays largely covered with scales  . . . . . . . . . .  
. . . . . . .  Leporellus vittatus (Valenciennes, 1850) (Fig. 3A)
1b: Caudal-fin rays not covered by scales other than imme-
diately proximate to hypurals . . . . . . . . . . . . . . . . . . . . . . (2)
2a: Mouth inferior. Premaxilla oriented such that long axis 
of premaxillary teeth points ventrally or slightly posteroven-
trally  . . . . . . . . . . . . . . . . . . . . . . . . . . . .  Hypomasticus (3)
2b: Mouth subterminal, terminal, supraterminal or superior, 
but not inferior. Premaxilla oriented such that long axis of 
premaxillary teeth points anteriorly or anteroventrally . . . (4)
3a: Lateral surface of body covered with numerous small 
spots, with spot below lateral line largest and surrounded by 
ring of eight discrete and evenly spaced spots (other spots 
also present on flanks) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . .  Hypomasticus megalepis (G?nther, 1863) (Fig. 4A)
3b: Lateral surface of body with multiple longitudinal dark 
stripes  . . . . . Hypomasticus despaxi (Puyo, 1943) (Fig. 4H)
4a: Premaxillary teeth, including symphyseal tooth, strong-
ly and uniformly bicuspid or multicuspid, with all cusps on 
each tooth roughly equivalent in size and forming continu-
ous jagged edge. Premaxillary teeth exclusive of tooth fur-
thest from symphysis all of approximately equal size . . . . (5)
4b: Premaxillary teeth not uniformly bicuspid or multicus-
pid; each tooth typically with single large central cusp (sym-
physeal premaxillary tooth bicuspid in Anostomoides, and 
some premaxillary teeth with additional smaller cusps in 
Leporinus). Premaxillary teeth decreasing in size in stepwise 
fashion posteriorly from symphysis  . . . . . . . . . . . . . . . . (15)
5a: in individuals over 40 mm SL dentary teeth incisiform 
and forming continuous bladelike cutting edge. individu-
als below 40 mm SL with multicuspid dentary teeth. dark 
pigmentation pattern of varying intensity present on body 
in individuals of all sizes, but typically with complete mid-
lateral stripe and four diffuse vertical bars on sides of body. 
dorsal surface of body with series of dark transverse bars in 
individuals smaller than 90 mm SL . . . . . . . . . . . . . . . . . . . .  
. . . . . . . . . . Laemolyta proxima (Garman, 1890) (Fig. 3E)
5b: in individuals of all sizes, dentary teeth multicuspid or 
some teeth with truncate margins, but series never forming 
continuous bladelike cutting edge. dark pigmentation pat-
tern variable, but not similar to condition described in 5a 
except in Schizodon vittatus (Valenciennes, 1850), which 
shares four vertical bars and, but has partial midlateral stripe 
restricted to caudal peduncle and lacks transverse bars across 
dorsal surface of body in individuals of all sizes . . . . . . . . (6)
6a: Body with four vertical dark bars and dark spot or par-
tial lateral stripe at base of median caudal-fin rays. Intensity 
of vertical bars greatest at lateral-line scale row. all dentary 
teeth strongly multicuspid resulting in overall jagged distal 
tooth margins. Exposed portion of dentary teeth wider than 
high. Mouth terminal in specimens larger than approximate-
ly 90 mm SL, slightly supraterminal in individuals between 
40 and 90 mm SL and distinctly supraterminal in individuals 
of less than 40 mm SL . . . . . . . . . . . . . . . . . .  Schizodon (7) 
6b: dark body pigmentation not as in 6a. dentary teeth 
either uniformly with two or more cusps or with symphyseal 
tooth having truncate margin. Exposed portion of dentary 
SidlauSkaS & Vari Anostomoid diversity in the Guianas
Cybium 2012, 36(1) 75
teeth higher than wide. Mouth superior in individuals of all 
sizes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (8)
7a: Body with dark lateral stripe connecting posteriormost 
vertical blotch to dark spot at base of median caudal-fin rays 
. . . . . . . . Schizodon vittatus (Valenciennes, 1850) (Fig. 3D)
7b: Body lacking dark lateral stripe connecting posterior-
most vertical blotch to dark spot at base of median caudal-fin 
rays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . Schizodon fasciatus Spix & Agassiz, 1829 (Fig. 3C)
8a: Pigmentation consisting of many wide dark vertical 
bands completely ringing body and separated by much thin-
ner light bands. Symphyseal tooth of dentary substantially 
longer than adjacent tooth. Lips with distinct papillae . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . .  Synaptolaemus cingulatus 
Myers and Fern?ndez-Y?pez, 1950 (Fig. 3J)
8b: Pigmentation not as in 8a. Symphyseal tooth of dentary 
approximately equal in size to adjacent tooth. Lips buckled 
and ridged, but without distinct papillae . . . . . . . . . . . . . . (9)
9a: Pigmentation on body consisting of numerous dark lon-
gitudinal stripes . . . . . . . . . . . . . . . . . . . . . . Anostomus (10)
9b: Pigmentation on body consisting of one or more dark 
spots centred on lateral-line scale row and dark transverse 
markings across dorsal surface of body. . . . . . . . . . . . . . (12)
10a: Pale middorsal stripe extending from tip of supraoc-
cipital spine to dorsal-fin origin. Several thin light and dark 
stripes on anterior half of body dorsal to thick dark stripe 
along lateral-line scale row. Three branchiostegal rays . . . . .
. . . .   Anostomus ternetzi Fern?ndez-Y?pez, 1949 (Fig. 3H)
10b: dark middorsal stripe extending from tip of supraoc-
cipital spine to dorsal-fin origin. Single dark stripe midway 
between middorsal stripe and midlateral stripe on lateral-line 
scale row. Four branchiostegal rays  . . . . . . . . . . . . . . . . (11)
11a: Greatest body depth 24.0-27.1% of SL (mean 25.6%) 
among specimens from Suriname. 12 caudal vertebrae, 
including ural centrum and vertebra of haemal spine which 
lies just anterior to first anal pterygiophore. Dorsal and cau-
dal fins hyaline in life. Red pigment not present on caudal 
peduncle, anal or pelvic fins in life . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . .  Anostomus brevior G?ry, 1961 (Fig. 3F)
11b: Greatest body depth 20.1-24.2% of SL (mean 21.9%) 
among specimens from Guyana and Suriname, the upper 
limit reached only in large individuals over 100 mm SL. 11 
(rarely 12 or 13) caudal vertebrae. Dorsal and caudal fins 
with red pigment in life. Red pigment sometimes present on 
caudal peduncle, anal fin and pelvic fins in life . . . . . . . . . . .
. . . . . . .  Anostomus anostomus (Linnaeus, 1758) (Fig. 3G)
12a: distal margin of symphyseal dentary tooth truncate in 
individuals greater than 60 mm SL, sometimes multicuspid 
in smaller individuals. Usually four well-defined dark spots 
along lateral-line scale row, though anteriormost spot some-
times faded. dark transverse bars present over entire body 
dorsal to lateral line, and usually below lateral line as well. 
Distance from snout to pelvic-fin origin usually greater than, 
rarely equal to, distance from dorsal-fin origin to caudal-fin 
origin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Petulanos (13) 
12b: Symphyseal dentary tooth bicuspid in individuals of 
all sizes (occasionally truncate from wear in large individ-
uals > 80 mm SL). Usually two or three well-defined dark 
spots along lateral-line scale row (four in Pseudanos graci-
lis [Kner, 1858], species not known from the Guianas). Dark 
transverse bars sometimes present across dorsum, but not 
present over entire body dorsal to lateral line. distance from 
snout to pelvic-fin origin less than, or equal to, distance from 
dorsal-fin origin to caudal-fin origin . . . . . .  Pseudanos (14)
13a: Transverse bars on body broad, typically two scales 
wide. 40-42 lateral-line scales. Second and third spots on 
lateral-line scale row typically three scales deep  . . . . . . . . .
. . .  Petulanos spiloclistron (Winterbottom, 1974) (Fig. 5B)
13b: Transverse bars on body thin, typically one scale wide. 
38-39 lateral-line scales. Second and third spots on lateral-
line scale row typically less than three scales deep . . . . . . . .
. . . . . . . . .  Petulanos plicatus (Eigenmann 1912) (Fig. 3K)
14a: Centres of scales dark, forming longitudinal rows of 
small spots along scale rows . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . Pseudanos irinae Winterbottom, 1980 (Fig. 3I)
14b: Centres of scales light. Occurrence in extreme south-
western Guyana based on single specimen from the Rio 
Puara in Rio ireng-Takutu-Branco system  . . . . . . . . . . . . . .
. . . . . . . . .  Pseudanos trimaculatus (Kner, 1958) (Fig. 5A)
15a: Body very deep and diamond shaped. Ten or more 
branched anal-fin rays. Three branchiostegal rays. Colour 
pattern with multiple alternating dark and light vertical bars 
on body and anterior portion of dorsal fin. Margins of pel-
vic and adipose fins intensely dark. Occurrence in extreme 
southwestern Guyana based on single specimen from indefi-
nite locality in ireng-Takutu-Branco system . . . . . . . . . . . . .
. . . .  Abramites hypselonotus (G?nther, 1868) (not figured)
15b: Body fusiform. Eight branched anal-fin rays. Usually 
four branchiostegal rays (three in Anostomoides). Colour 
pattern variably striped, barred or spotted, but similar to the 
condition in 15a only in Leporinus desmotes  . . . . . . . . . (16)
16a: Mouth supraterminal. Tip of symphyseal premaxillary 
tooth noticeably notched, forming two cusps. Three branchi-
ostegal rays. dark pigmentation on body consisting of one to 
three irregular vertical blotches and occasionally faint stripe 
along lateral-line scale row; stripe darkest near caudal-fin 
base . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . Anostomoides laticeps (Eigenmann, 1912) (Fig. 3B)
16b: Mouth terminal or subterminal. Symphyseal premaxil-
lary tooth typically with one large central cusp (one or two 
additional smaller cusps present in some species). Four bran-
chiostegal rays. dark pigmentation on body variable, but not 
as in 16a. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Leporinus (17)
Anostomoid diversity in the Guianas  SidlauSkaS & Vari
76 Cybium 2012, 36(1)
17a: dark pigmentation on body consisting of series of ver-
tical bars with intervening lighter regions . . . . . . . . . . . . (18)
17b: dark pigmentation on body not as in 17a (specimens 
may have dark longitudinal stripes, various patterns of spots, 
etc.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (20)
18a: dark pigmentation on body consisting of alternating 
wide and narrow vertical bars. Eight (rarely nine) branched 
pelvic-fin rays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  
. .  Leporinus maculatus M?ller & Troschel, 1844 (Fig. 4N)
18b: dark pigmentation on body consisting of multiple ver-
tical bars, each of approximately equal width. Nine branched 
pelvic-fin rays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (19)
19a: dark pigmentation on body in juveniles and adults 
consisting of seven or eight regularly spaced vertical bars 
beginning with bar situated on opercle; second bar typically 
in form of ?X?. additional dark bar present dorsal to eye in 
specimens of all sizes. Anterior portion of dorsal fin darkly 
pigmented. Mouth slightly subterminal. Symphyseal dentary 
teeth jaw distinctly elongate, laterally compressed and form-
ing distinct tusks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  
. . . . . . . . . . . . . Leporinus desmotes Fowler, 1914 (Fig. 4k)
19b: dark pigmentation on body in adults consisting of ten 
regularly spaced vertical bars beginning with bar situated on 
opercle. Large adults have bars partially split dorsally and 
ventrally by lighter regions, giving appearance of very nar-
row ?X?s. dark bar dorsal to eye present in juveniles, but 
faded or absent in some adults. dark pigmentation on body 
in juveniles with irregularly spaced bars, often arranged in 
sets of adjacent pairs. Anterior portion of dorsal fin hyaline 
(sometimes darkly pigmented in small juveniles). Mouth ter-
minal. Symphyseal dentary teeth larger than adjacent teeth 
but not distinctly elongate and laterally compressed into dis-
tinct tusks  . . .  Leporinus fasciatus (Bloch, 1794) (Fig. 4C)
20a: Multiple dark longitudinal stripes present on body, with 
stripe along lateral-line scale row widest and most intense . .  
. . . . . . . . . . . .  Leporinus arcus Eigenmann, 1912 (Fig. 4B)
20b: dark pigmentation on body not as in 20a . . . . . . . . (21)
21a: Shallow bodied, with maximum body depth 19-25% of 
SL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (22)
21b: Deep bodied, with maximum body depth 28-38% of 
SL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (24)
22a: dark partial stripe running along lateral-line scale row 
from below dorsal-fin base to caudal?fin base in individu-
als larger than 40 mm SL. Stripe sometimes interrupted with 
light bars in small juveniles under 40 mm SL. Three or four 
additional dark spots arranged in oblique row just posterior 
to opercle and ventral to lateral-line scale row . . . . . . . . . . .  
. . .  Leporinus nigrotaeniatus (Jardine, 1841) (Figs 4F, 4G)
22b: Multiple dark spots present along lateral-line scale row 
and at least one discrete spot situated ventral to that scale 
row in individuals of all sizes. additional dark spots variably 
present, but not in pattern described in 22a . . . . . . . . . . . (23)
23a: Five scales in transverse series above lateral line. Three 
pairs of spots positioned intermediate to four spots centred 
along lateral-line scale row. Each pair of spots with one 
member above lateral-line scale row and one below, with 
overall form of each pair reminiscent of colon . . . . . . . . . . .
. . . . . .  Leporinus ortomaculatus Garavello, 2000 (Fig. 4E)
23b: Six (rarely five) scales in transverse series above lateral 
line. Four large spots along midlateral surface of body; first 
centred just below lateral-line scale row and other three cen-
tred on lateral-line scale row, but without intervening pairs 
of dark spots reminiscent of colons. One discrete dark spot 
present ventral to seventh, eighth or ninth scale of lateral-
line scale row, between and below first and second midlat-
eral spot. Series of smaller dark spots variably present dorsal 
and ventral to lateral-line scale row. . . . . . . . . . . . . . . . . . . .  
. . Leporinus apollo Sidlauskas, Mol & Vari, 2011 (Fig. 6a)
24a: dark vertical bar on body outlining posterior margin of 
opercle dorsal to pectoral-fin insertion. Four dark spots cen-
tred along or just ventral to lateral-line scale row in individu-
als of all sizes and additional scattered spots in juveniles . . .  
. . . . . . Leporinus lebaili G?ry & Planquette, 1983 (Fig. 4D)
24b: No discrete dark pigmentation on body outlining poste-
rior margin of opercle dorsal to pectoral-fin insertion. Other 
dark pigmentation and spotting patterns variably present on 
body. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (25) 
25a: 12 circumpeduncular scales  . . . . . . . . . . . . . . . . . . . . .  
. . . . . . . . . . . . Leporinus nijsseni Garavello, 1990 (Fig. 6C)
25b: 16 circumpeduncular scales . . . . . . . . . . . . . . . . . . (26)
26a: Four scales in transverse series above lateral line . . . . .
. . . . . . . Leporinus gossei G?ry, Planquette & Le Bail, 1991 
(Fig. 4L)
26b: Five scales in transverse scales above lateral line . . (27)
27a: Body dorsal to lateral-line scale row with many scat-
tered discrete dark spots in individuals of all sizes. Speci-
mens 65 mm SL or larger usually with spots ventral to lateral 
line united into diffuse dark stripe. dark oblique stripe ven-
tral to eye . . . . Leporinus granti Eigenmann, 1912 (Fig. 6B)
27b: Body dorsal to lateral-line scale row unpigmented or 
with dusky vertical bars, but without many scattered discrete 
dark spots except in some small juveniles of L. friderici. 
dark spots ventral to lateral-line scale row variably present 
but never united into diffuse stripe. No dark stripe ventral to 
eye . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (28)
28a: Skin covering cleithrum immediately dorsal to pecto-
ral-fin insertion darkly pigmented. dark pigmentation on 
remainder of body absent or limited to single spot located on 
caudal peduncle near base of median caudal-fin rays . . . . . .  
. . . . . . .  Leporinus melanostictus Norman, 1926 (Fig. 4M)
SidlauSkaS & Vari Anostomoid diversity in the Guianas
Cybium 2012, 36(1) 77
28b: Skin covering cleithrum immediately dorsal to pecto-
ral-fin insertion not darkly pigmented. Dark pigmentation 
on caudal peduncle present or absent, but with at least one 
discrete spot or patch of pigmentation present elsewhere on 
body, particularly along lateral-line scale row below dorsal 
fin, except in very large individuals of Leporinus agassizi 
(~250 mm SL), which lack dark pigmentation on body and 
caudal peduncle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (29)
Figure 3. - anostomidae. A: Leporellus vittatus (preserved), AUM 20003, 123.6 mm SL, Venezuela, Portuguesa, R?o Portuguesa at high-
way 5 bridge. b: Anostomoides laticeps (preserved), ANSP 182274, Venezuela, Amazonas, Rio Orinoco, 52.9 km SE of San Antonio. 
c: Schizodon fasciatus (live, adult), Guyana, Rupununi River, 5.9 km WSW of village of Sand Creek, 02.967?N, 59.6592?W. d: Schizo-
don vittatus (preserved), AUM 35557, 97.1 mm SL, Guyana, Tukutu, Circle W Creek, tributary of Pirara River, 03.654?N, 59.529?W. 
e: Laemolyta proxima (preserved), AUM 45035, 134.4 mm SL, Guyana, Tukutu, pond at Yukupari, 3.659?N, 59.360?W. F: Anostomus 
brevior (live), FMNH ex ANSP 189141, Suriname, Sipalawini, Lawa River (Marowini drainage), 03.325?N, 54.063?W. G: Anostomus 
anostomus (live), USNM 403517, 52.7 mm SL, Guyana, Cuyuni River, 06.97?N 59.993?W. h: Anostomus ternetzi (preserved), MHNG 
2626.021, 56.1 mm SL, French Guiana, Maroni River, Saut Toulalapata. i: Pseudanos irinae (preserved), AUM 48740, Guyana, Tukutu, 
Rupununi River, Aruwa Falls, 03.502?N, 59.339?W. J: Synaptolaemus cingulatus (live), AUM 43269, Venezuela, Amazonas, R?o Orinoco, 
03.307?N, 66.600?W. K: Petulanos plicatus (preserved), ANSP 180173, Guyana, Rupununi, Essequibo River, Yukanopito Falls, 01.915?N, 
58.521?W. Scale bars indicate one centimetre. Photos by S. Moyers (A), B. Sidlauskas (B, H, K), M. Sabaj P?rez (C, F, J), J. Armbruster 
(d, E, i), and W. Bronaugh (G), 
Anostomoid diversity in the Guianas  SidlauSkaS & Vari
78 Cybium 2012, 36(1)
29a: Specimens smaller than approximately 100 mm SL . . .  
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (30)
29b: Specimens larger than approximately 100 mm SL . . . .  
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (31)
30a: Primary dark pigmentation on body consisting of inter-
mittent longitudinal stripe running along lateral-line scale 
row from position below dorsal-fin base to caudal pedun-
cle. Stripe composed of two to five spots, with at least some 
spots horizontally elongate. intensity and completeness of 
stripe highly variable, with anteriormost region typically 
darkest. Pigmentation of stripe particularly faint in material 
from demerara River, eastern Guyana. Smaller individuals 
usually with supplementary series of three or four small, 
vertically elongate spots present ventral to first through ninth 
scales of lateral-line scale row. Supplementary spots less 
intense in individuals of approximately 80 mm SL and dis-
appear entirely during course of ontogeny  . . . . . . . . . . . . . .
. . . . .  Leporinus agassizi  Steindachner, 1876 (Figs 4I, 7A)
30b: Primary dark pigmentation on body consisting of three 
distinct round spots along lateral-line scale row, one situ-
ated below dorsal?fin base, one slightly anterior to vertical 
through adipose-fin origin, and one on caudal peduncle. 
Juveniles with two or three smaller supplementary spots; 
first adjacent to opercle and centred on scale row just ventral 
to lateral-line scale row, second ventral to seventh and eighth 
lateral-line scales and third (when present) ventral to 20th 
and 21st lateral-line scales. Supplementary spots less intense 
in individuals of approximately 70 mm SL and disappear 
entirely during course of ontogeny . . . . . . . . . . . . . . . . . . . .  
  . . . . . . . . . . . . Leporinus friderici (Bloch, 1794) (Fig. 7B)
31a: all but largest specimens with single distinct dark spot 
along lateral-line scale row below dorsal?fin base and with 
additional dark pigmentation forming diffuse, irregular and 
interrupted band occasionally present along lateral-line scale 
row posterior to that point. intensity of dark pigmentation 
fades ontogenetically, with largest individuals (~250 mm 
SL) lacking dark pigmentation entirely, and slightly smaller 
individuals usually retaining only spot below dorsal-fin base. 
Midsized specimens occasionally retain patch of darker pig-
mentation along lateral-line scale row anterior of vertical 
through anterior of adipose fin reminiscent of second spot 
that characterizes adults of Leporinus friderici (see below) .
. . . . . . Leporinus agassizi Steindachner, 1876 (Figs 4J, 7A)
31b: Two or three dark spots present along lateral-line scale 
row in all but one examined individual; one spot situated 
below dorsal-fin base, second immediately anterior to ver-
tical through adipose-fin origin, and third variably present 
on caudal peduncle. Larger specimens typically retain dark 
mid-lateral spots, but intensity of spots sometimes fades in 
large individuals, with spot beneath dorsal fin darkest and 
spot over caudal peduncle lightest in those specimens. One 
large specimen from the Corantijn River weakly pigmented 
and displaying only anterior spot below dorsal?fin base . . . .  
. . . . . . . . . . . . . Leporinus friderici (Bloch, 1794) (Fig. 7B)
Comments on Anostomidae in Guyana, Suriname and 
French Guiana
With at least thirty recognizable morphospecies, the 
anostomidae represent the most diverse group of anosto-
moid fishes in the Guianas. identification of anostomids 
to genus is relatively unproblematic when it is possible to 
examine the dentition critically, but at a finer taxonomic scale 
the correspondence between many of the morphospecies and 
the available taxonomic names is unclear. We present below 
a brief genus-by-genus discussion of the taxonomic conun-
drums that abound in this group, and pay particular attention 
to our reasons for matching certain names to taxa. That said, 
our effort should not be considered a full taxonomic revision 
of these genera or their representatives in the Guianas!
Abramites. - There is a single specimen of Abramites 
hypselonotus (MHNG 2195.100) from an ambiguous locality 
in the Rio Branco drainage of extreme southwestern Guyana, 
where the Essequibo and Branco ichthyofaunas interchange 
through the Rupununi savannahs during high water periods 
(Lowe-McConnell, 1964; Watkins et al., 2005; de Souza et 
al., 2012). Abramites hypselonotus is primarily distributed 
through the amazon and Orinoco basins in northern South 
America (Vari and Williams, 1987, Fig. 6) and is clearly not 
a major component of the Guianese ichthyofauna. 
Anostomoides. - despite a type locality at Crab Falls 
in the Essequibo River drainage, Anostomoides laticeps is 
apparently a very rare member of the Guianese ichthyofauna. 
in addition to the type series we encountered only one addi-
tional from the Rupununi River (appendix Fig. 1). Within 
the Guianas it appears to be endemic to the Essequibo sys-
tem, though it also occurs in drainage systems beyond the 
Guianas, including the R?o Orinoco (Garavello and Britski, 
2003; Santos and Zuanon, 2006).
Anostomus. - Three species of Anostomus occur in 
the Guianas (appendix Fig. 2), bearing in mind the recent 
erection of Petulanos to contain several species formerly 
assigned to Anostomus (Sidlauskas and Vari, 2008). Anos-
tomus ternetzi (Fig. 3H) is easily distinguished on the basis 
of coloration (with a pale middorsal stripe from the tip of 
the supraoccipital spine to the dorsal-fin origin versus a dark 
median stripe in that region in congeners), but preserved 
specimens of A. anostomus and A. brevior are much more 
difficult to separate. Anostomus anostomus is the more slen-
der of the two species throughout ontogeny (see morphome-
tric diagnosis in key), though it does increase in relative 
body depth ontogenetically and large individuals of A. anos-
tomus approach the range of ratios that diagnose A. brevior. 
Identifications are much easier if live coloration is available, 
as A. brevior has hyaline fins (Fig. 3F), while A. anostomus 
has varying degrees of red pigmentation on the dorsal, cau-
SidlauSkaS & Vari Anostomoid diversity in the Guianas
Cybium 2012, 36(1) 79
dal, anal and pelvic fins and caudal peduncle (Fig. 3G). The 
relative extent of that red pigment varies considerably across 
the range of the species (compare Fig. 3G in this publication 
with plate 5B of Sabaj P?rez [2009]). Whether this difference 
indicates a morphocline, variable water chemistry or dietary 
composition, or the presence of multiple species within the 
present concept of A. anostomus is unknown. Within the 
Guianas, A. brevior has a more easterly distribution in the 
Litani-Marowijne and Oyapock systems of French Guiana 
and Suriname, while A. anostomus occurs in river systems 
further west. interestingly, A. ternetzi has a disjunct distribu-
tion in the Essequibo-Rupununi system and in the Marowi-
jne/Maroni system, without apparent occurrence in the inter-
vening river basins of Guyana and Suriname. Whether these 
disjunct populations merit formal taxonomic recognition is 
an open question. 
Hypomasticus. - Hypomasticus was recently elevated 
from a subgenus of Leporinus on the basis of several mor-
phological synapomorphies (Sidlauskas and Vari, 2008). 
Members of the genus can be recognized externally by 
their inferior mouths. Two species occur within the Guianas 
(Appendix Fig. 3), of which Hypomasticus despaxi (from the 
Maroni and Oyapock systems) is the simpler to recognize 
due to its highly distinctive striped colour pattern (Fig. 4H). 
Hypomasticus megalepis (Fig. 4a) from the Essequibo, 
Corantijn, Coppename and Maroni river systems is more 
problematic, as it has a spotted colour pattern very similar 
to that of Leporinus nijsseni (Fig. 6C), L. ortomaculatus 
(Fig. 4E) and L. granti (Fig. 6B). aside from the important 
difference in mouth position (inferior in H. megalepis versus 
terminal or subterminal in the above species of Leporinus), 
H. megalepis also possesses a distinct dark spot anteriorly 
on the base of the anal fin that is a continuation of a similar 
spot on the ventrolateral portion of body. Such an anal-fin 
spot is absent in Leporinus nijsseni, L. ortomaculatus and L. 
granti. 
it is noteworthy that a large percentage of material of 
Hypomasticus megalepis in collections was incorrectly iden-
tified as Leporinus maculatus, a name that applies correct-
ly to a species of Leporinus with alternating thick and thin 
dark vertical bars (Fig. 4N). The history behind that nomen-
clatural confusion was discussed extensively by G?ry et al. 
(1988). 
Laemolyta. - Of the five species in Laemolyta, only L. 
proxima (Fig. 3E) occurs in the Guianas (Mautari and Men-
ezes, 2006), with its distribution restricted to the Essequibo, 
Rupununi and Takutu river systems (appendix Fig. 4). it 
can be identified easily by the single continuous dark lateral 
stripe running from the eye to the posterior of the hypural 
plate and by the continuous incisiform margin formed by its 
dentary teeth. 
Leporellus. - The highly distinctive Leporellus vittatus 
(Fig. 3A), with dark stripes on the dorsal and caudal fins and 
an extensively scaled caudal fin, cannot be easily confused 
with any other anostomoid fish from the Guianas. It is rare 
in the ichthyofauna in this study area, being represented 
by only four examined lots, all from the Takutu or Rupu-
nuni rivers of southern Guyana (appendix Fig. 5). Outside 
the Guianas this nominal species has an exceedingly broad 
reputed range, including representation throughout the ama-
zon and Orinoco systems as well as the trans-andean drain-
ages of Colombia. Whether all populations from across that 
vast geographic swath truly belong to a single species is an 
unanswered question. 
Leporinus, general comments. - Leporinus is a large 
group of approximately 90 nominally valid species (Gar-
avello and Britski, 2003). The genus as currently defined is 
demonstrably paraphyletic (Sidlauskas and Vari, 2008), but 
in the absence of a comprehensive revision and associated 
phylogenetic analysis it is uncertain which components of 
the genus may in fact represent natural groups. Following 
G?ry (1977), we divide our discussion of these fishes into 
four almost certainly artificial groupings based on colour 
pattern (barred, striped, spotted or largely unpigmented) to 
facilitate location of comments pertinent to the identification 
of fishes in each group.
Leporinus, barred forms. - Within the barred or ban-
ded subgroup of Leporinus, three distinct morphospecies 
are present in the Guianas, which we have assigned to L. 
fasciatus (Fig. 4C), L. desmotes (Fig. 4k) and L. maculatus 
(Fig. 4N). Of these, L. maculatus is easily identified by its 
very distinctive alternating thick and thin dark bars. Lepori-
nus fasciatus and L. desmotes, that both possess dark bars 
of a more regular width are sometimes confused. These two 
can be separated by the number of dark vertical bars (gener-
ally ten in L. fasciatus versus seven or eight in L. desmotes, 
including the bar over the posterior of the opercle), the form 
of the symphyseal dentary teeth (laterally compressed, for-
ward jutting tusks in L. desmotes versus well developed 
but not tusk-like in L. fasciatus) and in the coloration of the 
anterior portion of the dorsal fin (darkly pigmented [Fig. 4K] 
in L. desmotes versus unpigmented [Fig. 4C] in L. fasciatus). 
Within the Guianas L. desmotes is limited to the southern 
portion of the Essequibo River system and the Takutu River 
(Rio Branco drainage), while L. fasciatus and L. maculatus 
are ubiquitous across the Guianas except for the Oyapock 
basin (appendix Figs 6, 7).
Though the three morphotypes of banded Leporinus are 
relatively easy to separate, some taxonomic uncertainty is 
associated with all three names. Leporinus desmotes was 
described from the Rupununi River of Guyana (Fowler, 
1914) and is the least problematic, though the nominal spe-
cies L. jatuncochi from Ecuador and Peru (Ovchynnyk, 
1971) is extremely similar and may be a junior synonym of 
L. desmotes. Leporinus fasciatus (Bloch, 1794) was one of 
the first three anostomid species to be described and it pos-
Anostomoid diversity in the Guianas  SidlauSkaS & Vari
80 Cybium 2012, 36(1)
SidlauSkaS & Vari Anostomoid diversity in the Guianas
Cybium 2012, 36(1) 81
sesses a large putative range spanning the major rivers of the 
Guianas as well the amazon and possibly the Orinoco sys-
tems. Several nominal subspecies (Borodin, 1929) as well as 
multiple possible junior synonyms have been proposed (Gar-
avello and Britski, 2003). Overall the L. fasciatus complex is 
in need of revision, but is it clear that the species present in 
the Guianas must be the true L. fasciatus, because the spe-
cies has a type locality within Suriname and no older name 
is available. 
The proper nomenclature of the species assigned herein 
to Leporinus maculatus is much less clear. Within the Guia-
nas, at least four names have been applied to species in this 
complex: L. alternus, L. maculatus, L. paralternus and L. 
pellegrinii, with L. maculatus being by far the oldest name. 
G?ry et al. (1988) argued convincingly that the other three 
names are synonyms of L. maculatus, with the proliferation 
of nominal species likely due to the incorrect application by 
ichthyologists of the name L. maculatus to the species rec-
ognized herein as Hypomasticus megalepis. G?ry et al. did, 
however, recognize two subspecies, L. maculatus maculatus 
(including L. paralternus) with a supplementary partial bar 
after the first major bar and a body depth 3.9 to 4.15 in SL, 
and L. maculatus pellegrinii (including L. alternus?) lack-
ing a supplementary partial bar and with a body depth 4.25 
to 4.45 in SL. Those cited subspecific differences appear 
inconsistent among the individuals we examined. One speci-
men (ANSP 180171), for example, lacks a supplementary 
bar but has a body depth of 4.18 in SL. The paratype of L. 
alternus (uSNM 66219) has a very slight supplementary bar 
in the form of a dark dot on the dorsum, despite the fact that 
the presence versus absence of the supplementary bar was 
the primary diagnostic feature used to separate L. paralter-
nus from L. alternus by Fowler (1914). Perhaps most tell-
ingly, variation within a single lot of specimens sometimes 
includes individuals demonstrating both colour patterns. 
a prime example is uSNM 225995, which has four speci-
mens with the supplementary bar ranging from dark, long 
and intense to completely absent. Overall the presence ver-
sus absence of the supplementary bar does not appear to be 
ontogenetic, and may represent sexual dimorphism or just 
natural intraspecific variation among individuals. It does not 
appear to diagnose reliably any taxon of any rank, and thus 
we assign all of the specimens of Leporinus with alternating 
thick and thin bars in the Guianas to L. maculatus. 
Figure 4 (left). - anostomidae. A: Hypomasticus megalepis (live), AUM 37999, Guyana, Region 9, Essequibo River, Kassi-Attae rapids, 
02.226?N, 58.393?W. b: Leporinus arcus (preserved), ANSP 179647, Guyana, Cuyuni-Mazaruni, Whitewater Creek, 6.8 km SSW of Bar-
tica, 06.378?N, 58.674?W. c: Leporinus fasciatus (live), ANSP 189158, Suriname, Sipalawini, Lawa River, eight km SSW of Anapaike-
Kawemhakan, 03.325?N, 54.063?W. d: Leporinus lebaili (live), FMNH ex ANSP 189043, Suriname, Sipalawini, Lawa River, eight km 
SSW of Anapaike-Kawemhakan, 03.325?N, 54.063?W. e: Leporinus ortomaculatus (live), AUM 43262, Venezuela, Amazonas, R?o Orino-
co, 147 km ESE of San Fernando de atabapo. F: Leporinus nigrotaeniatus (juvenile, live), USNM 403522, 32.2 mm SL, Guyana, Cuyuni 
River. G: Leporinus nigrotaeniatus (adult, preserved), USNM 377393, 106.2 mm SL, Guyana, Rupununi, Coco Creek. h: Hypomasticus 
despaxi (preserved), ANSP 189042, Suriname, Sipalawini, Lawa River, Gansoela, rapids eight km SSW of Anapaike, 03.311?N, 54.065?W. 
i: Leporinus agassizi (live), uSNM 402629, 95.1 mm SL, Guyana, Cuyuni River about 15 km upstream from Waikuri mountains near 
mouth of Toroparun River, 06.69186?N, 59.57722?W. J: Leporinus agassizi (live), USNM 403835, Guyana, Cuyuni River about 1 km 
downstream from Kanaima Falls, 06.88377?N, 60.24786?W. K: Leporinus desmotes (holotype, preserved), ANSP 39324, Guyana, Rupu-
nuni River. l: Leporinus gossei (preserved), MHNG 2700.051, 110.8 mm SL, French Guiana, Mana River Basin, Crique Aya, 04.603?N, 
53.418?W. M: Leporinus melanostictus (preserved), MHNG 2621.094, 118.0 mm SL, French Guiana, Fleuve Approuague, 04.193?N, 
52.319?W. n: Leporinus maculatus (live), FMNH ex ANSP 189041, Suriname, Sipalawini, Lawa River, eight km SSW of Anapaike-
Kawemhakan, 03.325?N, 54.063?W. Scale bars indicate one centimetre. Photos by M. Sabaj P?rez (A, C, D, E, H, K, N), B. Sidlauskas (B, 
G, L, M) and W. Bronaugh (F, i, J). 
Figure 5. - anostomidae. A: Pseudanos 
trimaculatus  (preserved), uSNM 
224797, 67.7 mm SL, Guyana, Rupu-
nuni, Puara River, amazon drainage. 
b: Petulanos spiloclistron (preserved), 
USNM 209432, 72.3 mm SL, Suri-
name, Fallawatre River, at rapids five 
km SSW of Stondansie Falls, 05.150?N, 
56.483?W. Photos by T. B. Griswold. 
Scale bars indicate one centimetre.
Anostomoid diversity in the Guianas  SidlauSkaS & Vari
82 Cybium 2012, 36(1)
Leporinus, striped forms. - Three striped 
species of Leporinus occur in the Guianas: L. 
arcus (Fig. 4B), L. nigrotaeniatus (Fig. 4F,G) 
and L. agassizi (Fig. 7a). Leporinus arcus is 
easy to identify due to its deep body with a 
wide dark midlateral stripe along the midline 
and an overall striped colour pattern remi-
niscent of members of Anostomus (Fig. 3F, 
G, H). Leporinus nigrotaeniatus is also very 
distinctive due to the combination of a very 
slender body (body depth at dorsal-fin origin 
approximately 18-21% of SL) with a partial 
dark midlateral stripe that runs from ventral 
to the dorsal-fin base to the posterior margin 
of the hypurals in adults (Fig. 4G). in small 
juveniles, the midlateral stripe is intermit-
tent (Fig. 4F). at middle stages of ontogeny, 
L. agassizi (Fig. 7a, centre) demonstrates 
a partial midlateral stripe similar to that 
present in L. nigrotaeniatus (Fig. 4G) but the 
former species has a distinctly deeper body 
(body depth at dorsal-fin origin approximate-
ly 28-32% of SL). The midlateral stripe in 
L. agassizi is, however, divided into a series 
of lateral spots at early stages of ontogeny 
(Fig. 7a, bottom), never completely forms in 
some individuals (Fig. 4i), and fades later in 
ontogeny (Fig. 7a, top) to disappear entire-
ly in very large adults (Fig. 4J). Leporinus 
agassizi is discussed more extensively below 
in a comparison with L. friderici. Within the 
Figure 6. - anostomidae. A: Leporinus apollo, holotype, FMNH 116827, 111.1 
mm SL Suriname, Saramacca, Coppename River, Sidonkrutu. b: Leporinus granti, 
uSNM 225402, 110.6 mm SL, Suriname, Nickerie district, stream into Lucie River, 
03.600?N, 57.617?W. c: Leporinus nijsseni, USNM 225377, 40.2 mm SL, Suri-
name, Nickerie District, stream at Machine Park, 03.833?N, 57.567?W. Scale bars 
indicate one centimetre. Photos by T. B. Griswold. 
Figure 7. - A: Growth series of Leporinus agassizi: Top, USNM 377364, 114.7 mm SL, Guyana. Centre, USNM 377410, 87.2 mm SL, 
Guyana, Burst Mouth Pond. Bottom, USNM 93438, 62.4 mm SL, Guyana, Wismar, 06.00?N, 58.55?W. b: Growth series of Leporinus 
friderici. Top, USNM 225383, 95.2 mm SL, Suriname, Nickerie, stream near Camp Anjoemara, 04.833?N, 57.433?W. Centre and bottom, 
USNM 225409, 68.3 and 55.7 mm SL. Suriname, Nickerie, Kamp Kreek, 04.817?N, 57.467?W. Scale bars indicate one centimetre. Photos 
by T. B. Griswold.
SidlauSkaS & Vari Anostomoid diversity in the Guianas
Cybium 2012, 36(1) 83
Guianas, L. agassizi and L. nigrotaeniatus occur through-
out the Essequibo River drainage but are unknown from the 
Corantijn River and drainages further to the east (appen-
dix Figs 8, 9). Leporinus arcus also occurs in the Essequibo 
drainage, but appears to be restricted to the northern half of 
Guyana and is unknown from the rivers of the Rupununi 
savannah (appendix Fig. 5). 
Leporinus, spotted forms. - any discussion of the spot-
ted species of Leporinus must confront the taxonomic confu-
sion that has surrounded the concept of L. friderici, which 
along with L. fasciatus and Anostomus anostomus was 
among the first three anostomid species to be recognized 
formally (Linnaeus, 1758; Bloch, 1794). In his description 
of Salmo friderici (now in Leporinus), which has an indefi-
nite type locality in Suriname, Bloch illustrated a large, fully 
adult individual with three distinct dark spots centred along 
the lateral-line scale row, one situated ventral to the dorsal 
fin, one just anterior to the vertical through the origins of 
the adipose and anal fins, and one on the caudal peduncle 
at the base of the medial caudal-fin rays. Bloch?s drawing 
and description very well match some recently collected 
Leporinus from the river systems of Suriname and French 
Guiana (Fig. 7B), although specimens smaller than the full 
adult illustrated by Bloch demonstrate additional faint bar-
ring dorsal to the lateral line and a mottled pattern ventral to 
the lateral line. There is little question that these individuals 
are the true L. friderici.
as is often the case with very early South american spe-
cies descriptions, the specific epithet of Leporinus friderici 
has also been applied to individuals from across the con-
tinent for more than 200 years since Bloch?s original work 
with the resultant species complex very much in need of 
revision. Though such a revision is beyond the scope of this 
work, it became clear during our survey that specimens from 
the Essequibo system of Guyana provisionally assigned to 
L. friderici (e.g., Figs 4i, 7a bottom panel) differ substan-
tially from specimens from the Corantijn River and drainages 
further east (Fig. 7B). The available material from the deme-
rara, Essequibo and Rupununi systems exhibits wide colour 
pattern variation, with most of the variability centred on the 
degree of completeness of a partial midlateral stripe remi-
niscent of the colour pattern that typifies the more slender L. 
nigrotaeniatus (Fig. 4F, 4G). individuals bearing a complete 
stripe between a point below the dorsal fin and the posterior 
margin of the hypurals resemble closely L. agassizi from the 
amazon drainage, while individuals in which the stripe is 
interrupted are very similar to the type series of L. punctatus 
Garavello, 2000, from the R?o Orinoco of Venezuela. Very 
small individuals (~60 mm SL and smaller, Fig. 6a, bottom 
panel) have a highly interrupted stripe that often appears as 
a series of five spots, of which only the spot ventral to the 
adipose fin is at all horizontally elongate. Such specimens 
have typically been identified as L. friderici in museum col-
lections, but differ from juveniles of L. friderici from the 
Corantijn River and drainages further east which have three 
distinct round spots centred along the lateral-line scale row in 
the region from ventral of the dorsal fin to the posterior mar-
gin of the hypurals, none of which is horizontally elongate. 
Matters are complicated further by ontogenetic variation. 
at approximately 90 mm SL, the colour pattern of speci-
mens of this complex from Guyana begins to fade and the 
lateral stripe becomes indistinct and begins to subdivide. 
indivi duals pass through a stage in which they possess hori-
zontally elongate dark markings in positions analogous to 
the three round spots that characterize L. friderici of Suri-
name and French Guiana (compare Fig. 4i with 7B). The 
posterior two spots then fade, leaving only a single dark spot 
ventral to the dorsal fin (Fig. 7A, top panel). Eventually that 
spot similarly fades with the largest known individuals from 
the Essequibo drainage completely lacking midlateral dark 
markings (Fig. 4J). This contrasts sharply with the condition 
in L. friderici from the Corantijn River and drainages fur-
ther to the east (appendix Fig. 9), in which adults maintain 
at least the anterior two dark marks throughout onto geny. a 
full series of intermediates can be assembled to link all of the 
forms in the Essequibo, Rupununi and demerara systems, 
and it seems clear that all these represent a single, morpho-
logically variable species. For the most part the varia tion 
among individuals of the same size does not appear to be 
geographically structured, though the available specimens 
(mostly juveniles) from the demerara River are particularly 
weakly pigmented. 
Overall, it is very clear that the material from the deme-
rara, Essequibo and Rupununi rivers is not conspecific with 
Leporinus friderici which occurs in river systems to the east 
(appendix Fig. 9). Those western populations are identi-
fied herein as L. agassizi, which is the oldest available name 
that appears to match at least a portion of the ontogenetic 
pigmentation pattern of that nominal species (namely the 
striped phase). Problematically, L. agassizi has a type loca-
lity in the amazon drainage rather than one of the drainages 
of the northern Guiana Shield. as discussed above, L. punc-
tatus from the R?o Orinoco basin is another possibly conspe-
cific species, and indeed it is possible that L. agassizi and 
L. punctatus are synonymous. a third possibility is that the 
material from the demerara, Essequibo and Rupununi rivers 
represents a species new to science. Only a thorough com-
parison of samples from these and adjoining drainage basins 
with the relevant type series can resolve this issue. 
Variation within Leporinus friderici proper is problem-
atic in that we were unable to examine enough specimens 
from French Guiana to evaluate the diagnosability of the 
two putative subspecies L. friderici friderici and L. friderici 
acutidens. according to Planquette et al. (1996) L. friderici 
acutidens has a concave anal fin margin while L. friderici 
friderici has a straight or convex margin. We would con-
Anostomoid diversity in the Guianas  SidlauSkaS & Vari
84 Cybium 2012, 36(1)
sider the fin margins of the extensive series of material that 
we examined from Suriname to be straight, or very slightly 
concave (e.g., Fig. 7B, top panel). That said, there remains 
substantial co lour pattern variation within L. friderici. Mod-
erately to large sized specimens from Suriname (e.g., FMNH 
116829) have little in the way of supplementary markings 
above and below the lateral-line scale row and have fairly 
small, but discrete lateral-line spots. Some material from 
the Nickerie River of Suriname (e.g., uSNM 225772, a lot 
of specimens at about 97 mm SL) has the pigmentation of 
the second and third spots in some individuals less intense 
than that of the spot below the dorsal fin. Material from fur-
ther east in Suriname and French Guiana (Lawa/Marowijne 
drainage, e.g., ANSP 189264) tends to have more pigmenta-
tion, retains distinct spots below the lateral line until at least 
80 mm SL and has overall larger spots. Determination of 
whether this variation indicates a morphocline, natural varia-
tion among individuals or the presence of recogni zable east-
ern and western taxa within the present concept of L. frideri-
ci will require the examination of more extensive series of 
specimens, and will unfortunately be complicated by the fact 
that no types are known for L. acutidens, which has a type 
locality simply of ?South america?.
Identification of the remaining spotted species of Lepori-
nus in the Guianas is much more straightforward. The two 
species most similar to L. friderici and L. agassizi are L. gos-
sei from the Marowijne and Oyapock drainages of French 
Guiana (appendix Fig. 5) and L. lebaili from the Marowijne 
(appendix Fig. 11). Leporinus gossei (Fig. 4L) posses ses 
a colour pattern very similar to that of L. friderici but has 
only four scales in the upper transverse series (versus five 
in L. friderici) and usually retains into adulthood a dark spot 
posterior to the opercular margin centred just ventral to the 
lateral-line scale row (versus the lack of such a dark spot in 
adulthood). Leporinus lebaili (Fig. 4d) is easily recognized 
by the dark black pigmentation on the body that outlines the 
posterior margin of the opercular series (versus a lack of 
such pigmentation in L. friderici). 
Leporinus nijsseni (Fig. 6C) can be separated from other 
spotted species of Leporinus in the Guianas by the presence 
of 12 rather than 16 circumpeduncular scales. This species 
other wise looks very similar to L. granti at small sizes (under 
65 mm SL), as both have a very heavily spotted colour pattern. 
Interestingly, material fitting the current concept of L. nijsseni 
appears to have a disjoint distribution in the Corantijn, Nick-
erie, Suriname and Coppename rivers of Suriname and in the 
Oyapock River of French Guiana, without apparent occur-
rence in the intervening Litani/Marowijne, Mana, Sinnamary 
or approuague river systems (appendix Fig. 1). Leporinus 
nijsseni also bears a close similarity to the poorly known L. 
steyermarki Inger, 1956, from the R?o Ab?capa, which drains 
a tepui in Venezuela at a height of approximately 400 m 
above sea level (inger, 1956). Leporinus steyermarki also has 
a spotted colour pattern and 12 circumpeduncular scales, but 
can theoretically be separated from L. nijsseni by the posses-
sion of 32 lateral-line scales (versus 33-36 in L. nijsseni). a 
revision is necessary to determine whether the two disjunct 
populations of L. nijsseni merit recognition as distinct species 
or subspecies, and whether either is in the synonymy of the 
older L. steyermarki. 
Leporinus granti, another heavily spotted, deep bod-
ied species of Leporinus is easily recognized at sizes over 
65 mm SL by the presence in most specimens of a diffuse 
dusky stripe ventral to the lateral-line scale row (Fig. 6B). 
at small sizes the pigmentation ventral to the lateral-line 
scale row instead consists of a series of disconnected dark 
spots and L. granti looks very similar to L. friderici, L. nijs-
seni and Hypomasticus megalepis. Nevertheless, juveniles 
of Leporinus granti can be recognized by the presence of 16 
circumpeduncular scales (versus 12 in L. nijsseni), a termi-
nal mouth (versus inferior in Hypomasticus megalepis) and a 
dark oblique stripe under the eye (versus the absence of such 
a stripe in all three cited species). Leporinus friderici is also 
much less extensively spotted at all stages of ontogeny than 
is L. granti. Leporinus granti appears commonly through-
out the Branco, Essequibo, Corantijn, and Marowijne up to 
approuage basins but is notably absent in the Nickerie, Cop-
pename, Saramacca and Suriname drainages of central Suri-
name and the Oyapock system of far eastern French Guiana 
(appendix Fig. 10). The very similar L. nijsseni occurs in 
drainages where L. granti does not (appendix Fig. 1) except 
for a possible area of contact in the Corantijn system, sug-
gesting that these two taxa may be allopatrically-generated 
sister species. Furthermore, both of these species appear to 
have disjoint distributions, suggesting the possible presence 
of cryptic species within the present concept of both taxa. 
The remaining two species of spotted Leporinus from 
the Guianas are much more slender-bodied than the spotted 
species discussed above, with body depth at the dorsal-fin 
origin in the range of 19%-25% of SL, versus 28%-38% of 
SL. Leporinus ortomaculatus (Fig. 4E) is widely distributed 
throughout the Orinoco system (Garavello, 2000) but also 
occurs in the Takutu and ireng drainages (Rio Branco basin) 
of southwestern Guyana (Appendix Fig. 8). It is a heavily 
spotted species with three pairs of spots positioned interme-
diate to four spots centred along lateral-line scale row. Each 
pair of spots is positioned with one member above lateral-
line scale row and one below, with the overall form of each 
pair reminiscent of a colon. 
Finally, a new spotted species, Leporinus apollo Sid-
lauskas et al. 2011 (Fig. 6a) was discovered recently from 
the Coppename, Corantijn and Suriname rivers of Suri-
name (appendix Fig. 4). it is extremely slender (body depth 
18-23% of standard length), has a colour pattern of four large 
lateral spots and additional dark markings ventral to the lat-
eral line, and has six upper transverse scales versus the five 
SidlauSkaS & Vari Anostomoid diversity in the Guianas
Cybium 2012, 36(1) 85
in most other species of Leporinus in the Guianas. This new 
species is most similar to L. cylindriformis Borodin, 1929 
and L. niceforoi Fowler, 1943, from the Amazon drainage, 
but can be distinguished from those species by details of pig-
mentation, morphometrics and meristics (Sidlauskas et al., 
2011). 
Leporinus, largely unpigmented species. - Within the 
Guianas, L. melanostictus from the approuague and Oyapock 
river systems of French Guiana is the only species of Lepori-
nus that lacks major dark markings on the body at all stages 
of ontogeny (Fig. 4M). That species usually (but not always) 
has a dark spot on the caudal peduncle, which is aligned with 
the bases of the median caudal-fin rays, and has dusky pig-
mentation in the skin covering the cleithrum just dorsal to the 
pectoral-fin insertion. Otherwise, the body is unpatterned. 
Very large (~250 mm SL) individuals of L. agassizi from the 
Essequibo River of Guyana lose the lateral spotting or strip-
ing that characterizes that species at earlier stages of ontog-
eny and potentially can be confused with L. melanostictus. 
aside from its non-overlapping geographic range, members 
of L. agassizi (Figs 4i, 4J) lack the dusky pigmentation on the 
cleithrum that is typical of L. melanostictus. 
Pseudanos. - Though two species of Pseudanos appear 
in the key above, only P. irinae (Fig. 3I) is a major com-
ponent of the ichthyofauna of the Guianas, where it occurs 
throughout the Essequibo and Rupununi river systems 
(appendix Fig. 11). a single specimen of P. trimaculatus 
(uSNM 224797, Fig. 5a) is known from the Puara River 
(Rio Branco drainage) of southern Guyana. This species is 
a common component of the ichthyofauna of the Rio Negro 
including the Branco but only occurs peripherally within the 
Guianas proper. 
Petulanos. - Two species within the Guianas were until 
recently assigned to Anostomus, but were assigned to a new 
genus, Petulanos, to reflect the numerous morphological 
synapomorphies that separate those two genera (Sidlauskas 
and Vari, 2008). The combination of a superior mouth with a 
multiply spotted and barred colour pattern readily separates 
these species from all other anostomids in the Guianas with 
the possible exception of Pseudanos. Members of Pseudanos 
(e.g., Fig. 3I) possess much less extensive transverse bar-
ring than do members of Petulanos (e.g., Fig. 5B), and have 
multicuspid rather than truncate symphyseal dentary teeth. 
Numerous skeletal differences also separate the two genera 
(Sidlauskas and Vari, 2008). Of the two species of Petulanos 
present in the Guianas, P. plicatus (Fig. 3K) has a more west-
erly distribution in the Essequibo and Corantijn river systems 
while P. spiloclistron (Fig. 5B) is endemic to the Nickerie 
River (appendix Fig. 12). Neither species is known to occur 
outside the Guianas, and with only one other known species 
in the genus (P. intermedius [Winterbottom, 1980] from the 
Rio Xingu in Brazil), this is one of the most highly endemic 
fish genera in the region targeted by this study.
Schizodon. - Two recognizable morphotypes of Schizo-
don exist within the study area, one with a partial midlate-
ral stripe restricted to the caudal peduncle (Fig. 3D) and the 
other lacking such pigmentation (Fig. 3C). Both morphotypes 
occur in the Rupununi (Essequibo basin) and ireng (Branco 
basin) rivers of southern Guyana (Appendix Fig. 13) where 
the genus is a common member of the ichthyofauna, most 
likely due to the presence of abundant submerged and floa-
ting vegetation on which members of the genus feed (Santos, 
1981; Sidlauskas et al., 2007). Only the non-striped form is 
known from Suriname and French Guiana, although admit-
tedly based on a limited sample of six lots from the Corantijn, 
Maroni and Mana drainages. The occurrence of striped and 
non-striped morphotypes have been recognized among ama-
zonian specimens since the mid-nineteenth century (Spix and 
Agassiz, 1829; Cuvier and Valenciennes, 1850), when they 
were assigned the nominal species names Piabuca vittatus 
and Schizodon fasciatus respectively. G?ry (1977) questioned 
the validity of these two species, and suggested that Schizo-
don fasciatus and its junior synonym S. vittatus are colour 
morphs. interestingly, in our samples no individuals larger 
than approximately 130 mm SL exhibited the striped mor-
photype, while non-striped individuals above and below that 
size threshold were present. it is possible that the stripe, when 
present, fades over the course of ontogeny and that only a sin-
gle species of Schizodon inhabits the Guianas. alternatively, 
there may in fact be two species of Schizodon present in the 
region, with the striped form (nominally S. vittatus) perhaps 
achieving a lower maximum size. Resolution of this question 
and the related issue of whether the Schizodon populations in 
the Guianas are conspecific with Amazonian forms requires a 
full taxonomic revision of the genus; and is beyond the scope 
of this study. We have tentatively divided the striped versus 
non-striped morphs into the two nominal species and plotted 
their distributions separately. 
Synaptolaemus. - The highly distinctive Synaptolaemus 
cingulatus (Fig. 3J), with its body encircled by numerous 
thick dark bands separated by lighter bands which are red 
in life, a strongly superior mouth, and papillose lips, can-
not be confused with any other fish in the Guianas. Most of 
the known range of this species lies within the R?o Orinoco 
drainage of Venezuela (Winterbottom, 1980), but it has also 
been captured within the Takutu River of southwestern Guy-
ana (appendix Fig. 1). a population is also known from the 
upper Rio Xingu of Brazil (Winterbottom, 1980). 
Key to Chilodontidae in Guyana, Suriname and French 
Guiana
1a: Branched anal-fin rays typically ten or eleven, rarely 
nine. Anal-fin margin convex or straight. Mouth terminal or 
Anostomoid diversity in the Guianas  SidlauSkaS & Vari
86 Cybium 2012, 36(1)
slightly superior. Dorsal fin with series of dark spots on pos-
terior rays. Posterior margin of scales smooth  . . . . . . . . . . .  
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Chilodus (2)
1b: Branched anal-fin rays six to eight. anal-fin margin 
somewhat concave in nearly all specimens. Mouth subtermi-
nal. Dorsal fin with dark pigmentation across distal portions 
of anterior rays but lacking dark spots on remaining portions 
of fin. Posterior margin of scales weakly serrate . . . . . . . . . .  
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Caenotropus (3)
2a: Conspicuous dark spots evenly distributed over body; 
spots about one-half diameter of pupil of eye. Spots promi-
nent on anteroventral portion of body and of approximately 
same size across entire body. Midlateral stripe absent  . . . . .  
. . . . . . . . . . . . . . . . .Chilodus zunevei Puyo, 1946 (Fig. 8D)
2b: dark spots variably present on body, but largest spots 
only one-quarter diameter of pupil of eye. Spots more dif-
fuse and nearly absent on anteroventral portion of body and 
often smaller ventrally. Midlateral portion of body with dark 
pigmentation ranging from irregular zigzag pattern to dis-
tinct stripe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . Chilodus punctatus M?ller & Troschel, 1844 (Fig. 8C)
3a: Lateral-line scales, not including terminal elongate scale, 
typically 27 or 28, most often 27. Most individuals with row 
of well spaced teeth in lower jaw although with row reduced 
to one or two teeth in some individuals. distal portions of 
anterior dorsal-fin rays with distinct patch of dark pigmenta-
tion. distinct midlateral stripe extending from snout to cau-
dal fin-base without dark spot positioned along stripe in area 
slightly anterior of vertical through dorsal-fin origin  . . . . . .  
. . . . . Caenotropus maculosus (Eigenmann, 1912) (Fig. 8B)
3b: Lateral-line scales, not including terminal elongate scale, 
28 to 32, most often 29 or 30 and rarely 28. Teeth absent in 
lower jaw. Distal portions of anterior dorsal-fin rays some-
times dusky but lacking distinct patch of dark pigmentation. 
diffuse midlateral stripe extending from snout to caudal 
fin-base, most often with rotund dark spot positioned along 
stripe in area slightly anterior of vertical through dorsal-fin 
origin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  
. . . . . . . . Caenotropus labyrinthicus (Kner, 1858) (Fig. 8A)
Comments on Chilodontidae from Guyana, Suriname 
and French Guiana
With just four species present in the Guianas, the Chilo-
dontidae represent a relatively minor component of the over-
all ichthyofauna of that region. it is notable, however, that 
these four species represent 50% of the total number of spe-
cies in this small family. Endemicity of the members of this 
family occurring in the Guianas is also at 50%, with Chi-
lodus zunevei (appendix Fig. 15) and Caenotropus maculo-
sus (appendix Fig. 14) both restricted to the region (isbr?ck-
er and Nijssen, 1988; Vari et al., 1995). The diagnosis of all 
four species is easily accomplished on the basis of coloration 
(Fig. 8), meristics and mouth position. 
Key to Curimatidae in Guyana, Suriname and French 
Guiana
1a: Lateral line incomplete in specimens of all sizes. anterior 
Figure 8. - Chilodontidae. A: Caenotropus labyrinthicus (preserved). ANSP 135851, Venezuela, Bolivar. R?o Nichare, 06.583?N, 64.817?W. 
b: Caenotropus maculosus (live), ANSP 189147, Suriname, Sipalawini, Litanie River, 03.290?N, 54.077?W. c: Chilodus punctatus (pre-
served), AUM 36902, Guyana, Region 9, Rupununi River, 03.808?N, 59.385?W. d: Chilodus zunevei (preserved), MHNG 2608.040, 55.6 
mm SL, French Guiana, Kaw, Kaw river basin, Wapou Creek at D?grad Roche, 04.429?N, 52.158?W. Scale bar indicates one centimetre. 
Photos by T. B. Griswold (a), M. Sabaj P?rez (B), J. armbruster (C) and B. Sidlauskas (d). 
SidlauSkaS & Vari Anostomoid diversity in the Guianas
Cybium 2012, 36(1) 87
margin of maxilla distinctly rounded and extending anterior-
ly to pronounced degree when lower jaw depressed. Mature 
males with pronounced expansion of penultimate principal ray 
of lower lobe of caudal fin. Relative depth of caudal peduncle 
sexually dimorphic, deeper in mature male . . . . . . . . . . . . . .
. . . . . . . . . Curimatopsis crypticus Vari, 1982 (Figs 9A, 9D)
1b: Lateral line complete in all but small juveniles. anterior 
margin of maxilla slightly convex to slightly concave anteri-
orly and not extending anteriorly to a pronounced degree when 
lower jaw depressed. No sexual dimorphism apparent in rays 
of caudal fin or in relative depth of caudal peduncle  . . . . . . . (2)
2a: Middle rays of caudal-fin lobes covered with patches of 
scales smaller than those on body, with most of lobes cov-
ered by scales in larger specimens . . . . . . . . .Curimatella (3)
2b: Middle rays of caudal-fin lobes lacking scales smaller 
than those on body or scales limited to basal portions of 
lobes even in larger specimens . . . . . . . . . . . . . . . . . . . . . (4)
3a: Interorbital width 45-50% of HL. Gape width 28-33% 
of HL. Length of postorbital portion of head 39-45% of HL. 
Orbital diameter 27-32% of HL  . . . . . . . . . . . . . . . . . . . . . .
  Curimatella alburna (M?ller & Troschel, 1844) (Fig. 10A)
3b: Interorbital width 38-45% of HL. Gape width 24-29% 
of HL. Length of postorbital portion of head 36-40% of HL. 
Orbital diameter 33-39% of HL  . . . . . . . . . . . . . . . . . . . . . .
. Curimatella immaculata (Fern?ndez-Y?pez, 1948) (Fig. 10E)
4a: Elaborations of soft tissues on roof of mouth limited to 
three simple, non-fleshy longitudinal folds (Fig. 11A). Folds 
not paralleled by series of secondary fleshy folds. No lobu-
late fleshy bodies extending ventrally into oral cavity  . . . (5)
4b: Roof of mouth with three fleshy longitudinal folds paral-
leled by series of secondary folds (Fig. 11B), or with series 
of lobulate fleshy bodies extending ventrally into oral cavity 
(Fig. 11C)  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (14)
5a: Laterosensory canal segment in sixth infraorbital tri-
partite (Fig. 12a). Laterosensory canal segments in fourth 
and fifth infraorbitals forming arch continuous with canal 
segments in more anterior infraorbitals (Fig. 13A). Fourth 
infraorbital with distinct posteriorly oriented branch of lat-
Figure 9. - Curimatidae. A: Curimatopsis crypticus (female, live), ANSP 189091, Suriname, Para, Suriname River basin, Coropinae Creek, 
vicinity of Republiek, 05.499?N, 55.214?W. b: Curimata vittata (male, preserved), USNM 304862, 169.7 mm SL, Venezuela, Amazonas, 
R?o Macava, near Tapirapeco. c: Curimata cyprinoides (preserved), 137.9 mm SL, USNM 402472, Guyana, Cuyuni River. d: Curimat-
opsis crypticus (male, live), FMNH ex ANSP 189091, Suriname, Para, Suriname River basin, Coropinae Creek, vicinity of Republiek, 
05.499?N, 55.214?W. e: Cyphocharax spilurus (live), USNM uncataloged, 34.7 mm SL, Guyana, Cuyuni River, 06.845?N, 60.130?W. 
F: Cyphocharax helleri (preserved), ANSP 189154, Suriname, Sipalawini, Lawa River, eight km SSW of Anapaike-Kawemhakan, 
03.325?N, 54.063?W. Photos by M. Sabaj P?rez (A, D, F), S. Raredon (B) and W. Bronaugh (C, E).
Anostomoid diversity in the Guianas  SidlauSkaS & Vari
88 Cybium 2012, 36(1)
erosensory canal segment in that bone (Fig. 13A)  . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Psectrogaster (6)
5b: Laterosensory canal segment in sixth infraorbital in 
form of simple tube (Fig. 12d). Laterosensory canal seg-
ments in fourth and fifth infraorbitals meeting at acute angle 
(Fig. 13C). Fourth infraorbital lacking distinct posteriorly 
oriented branch coming off laterosensory canal segment in 
that bone (Fig. 13C)  . . . . . . . . . . . . . . . . . Cyphocharax (7)
6a: Prepelvic region distinctly flattened transversely and 
bordered laterally by distinct, nearly right, angles in body 
wall. Longitudinal series of distinctly enlarged median scales 
along prepelvic region flanked by row of enlarged scales 
conforming to lateral angles of body. Nine (rarely eight or 
ten) branched pelvic-fin rays . . . . . . . . . . . . . . . . . . . . . . . . .  
. . . . Psectrogaster essequibensis (G?nther, 1864) (Fig. 10F)
6b: Prepelvic region transversely rounded and not bordered 
by distinct, nearly right, angles in body wall. Midventral and 
adjoining scales irregularly arranged and not enlarged. Eight 
branched pelvic-fin rays  . . . . . . . . . . . . . . . . . . . . . . . . . . . .  
. Psectrogaster ciliata (M?ller & Troschel, 1844) (Fig. 10B)
7a: Caudal peduncle lacking distinct dark midlateral pig-
mentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (8)
7b: Caudal peduncle with distinct dark pigmentation in form 
of rounded, horizontally elongate or triangular spot . . . . (10)
Figure 10. - Curimatidae. A: Curimatella alburna (preserved), MZuSP 6425, Brazil, amazonas, igarap? Chefe, Lago Beruri. b: Psec-
trogaster ciliata (preserved), USNM 269990, 84.0 mm SL, Venezuela, Bolivar, ca?o entering R?o Orinoco, S of El Burro. c: Curimata 
roseni (preserved, holotype), MZUSP 28651, Brazil, Roraima, Rio Branco, Cachoeira de Bem Querer. d: Steindachnerina planiventris 
(preserved), MZUSP 38557, Brazil, Rond?nia, Rio Machado, near mouth. e: Curimatella immaculata (preserved), USNM 269928, 42.3 
mm SL, Venezuela, Bolivar, ca?o entering R?o Orinoco S of El Burro. F: Psectrogaster essequibensis (preserved), USNM 267339, 73.3 
mm SL, Peru, Loreto, R?o Amazonas, Santa Rosa. G: Steindachnerina guentheri (preserved), USNM 298034, 77.4 mm SL, Peru, Ucay-
ali, Pucallpa, R?o Neshuya, 60 km W of Pucallpa. h: Steindachnerina varii (preserved), ZMa120.501, Suriname, Brokopondo district, 
Morawijne or Gran Kreek, 63 km S of Afobaka. Scale bars indicate one centimetre. Photos by T. B. Griswold. 
SidlauSkaS & Vari Anostomoid diversity in the Guianas
Cybium 2012, 36(1) 89
8a: Lateral-line scales from supracleithrum to hypural joint 
39-45 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . .Cyphocharax leucostictus (Eigenmann & Eigenmann, 
1889) (Fig. 14C)
8b: Lateral-line scales from supracleithrum to hypural joint 
29-34 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (9)
9a: Scales with dark pigmentation more intense along dor-
sal and ventral margins, forming faint longitudinal stripes in 
smaller individuals and distinct dark irregular stripes in larg-
er specimens. Greatest body depth equal to distance from tip 
of snout to posterior margin of fourth scale of lateral line. . . 
. . Cyphocharax microcephalus (Eigenmann & Eigenmann, 
1889) (Fig. 14D)
9b: Scales lacking concentration of darker pigmentation dor-
sally and ventrally and longitudinal stripes absent. Greatest 
body depth equal to distance from tip of snout to posterior 
margin of second scale of lateral line  . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . Cyphocharax festivus Vari, 1992 (Fig. 14a)
10a: Body with dark midlateral spot in region below dorsal-
fin base  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (11)
10b: Body without dark midlateral spot in region below dor-
sal-fin base. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (12) 
11a: Rounded midlateral dark spot in region below dorsal-fin 
base in all but specimens under 20 mm SL. Spot ranges from 
diffuse concentration of dark chromatophores in individuals 
of 18-45 mm SL to distinct black spot in larger specimens. 
No dark midlateral spots present in region between spot 
below dorsal-fin base and spot at rear of caudal peduncle  . .
. Cyphocharax biocellatus Vari, Sidlauskas & Le Bail, 2012 
11b: One rounded midlateral very dark spot in region below 
dorsal-fin base in all specimens (18-42 mm SL). Spot under 
dorsal-fin followed posteriorly by two or three dark spots on 
midlateral surface of body and dark spot at rear of caudal 
peduncle  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. Cyphocharax punctatus (Vari & Nijssen, 1986) (Fig. 14E)
12a: dark triangular spot on midlateral surface of caudal 
peduncle with nearly straight anterior margin . . . . . . . . . . . .
. . . . . . . . . . . Cyphocharax gouldingi Vari, 1992 (Fig. 14B)
12b: dark rounded or horizontally elongate spot on mid-
lateral surface of caudal peduncle with rounded anterior 
margin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (13)
13a: Body with dark striping along lateral and dorsolateral 
portions of body; striping located along boundaries between 
rows of scales but faint in some individuals. dark spot on 
midlateral surface of caudal peduncle rounded and reach-
ing to, or nearly to, bases of dorsalmost and ventral princi-
pal caudal-fin rays. Dusky pigmentation absent from basal 
region of exposed portion of scales of lateral and dorsolater-
al portion of body; body without reticulate pigmentation pat-
tern. in individuals smaller than 70 mm, body depth at dor-
sal-fin origin 38.3-43.8% of SL, mean 40.9%. Proportional 
body depth decreasing over ontogeny (Fig. 15), with mean 
body depth at dorsal-fin origin 37.0% SL (range 35.2%-
39.0%) in individuals over 70 mm SL . . . . . . . . . . . . . . . . . .
. . . . . . .Cyphocharax helleri (Steindachner, 1910) (Fig. 9F)
13b: Body without dark striping along lateral and dorsola-
teral portions of body. dark spot on midlateral surface of 
caudal peduncle horizontally elongate and with dorsal and 
ventral margins of spot falling short of base of dorsalmost 
Figure 11. - Ventral views of roof of mouth showing form of projections of soft tissues. A: Cyphocharax gouldingi, USNM 268006, 
82.2 mm SL; b: Curimata cyprinoides, USNM 267963, 86.1 mm SL; c: Steindachnerina guentheri, USNM 298031, 90.0 mm SL. 
Anostomoid diversity in the Guianas  SidlauSkaS & Vari
90 Cybium 2012, 36(1)
and ventral principal caudal-fin rays. Dusky pigmentation 
on basal portion of exposed scales of lateral and dorsolateral 
portions of body, sometimes resulting in reticulate pattern. 
individuals smaller than 70 mm with body depth at dorsal 
fin origin 32.3-36.6% of SL, mean 34.1%. Proportional body 
depth roughly constant (increasing very slightly) over ontog-
eny (Fig. 15), with mean body depth at dorsal-fin origin 
34.4% SL (range 32.1%-38.1%) in individuals over 70 mm 
SL . . . . . . Cyphocharax spilurus (G?nther, 1864) (Fig. 9E)
14a: Roof of mouth with three fleshy longitudinal folds par-
alleled by series of secondary folds (Fig. 11B) . . . . . . . . . . .  
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Curimata (15)
14b: Roof of mouth with series of lobulate fleshy bodies 
extending ventrally into oral cavity (Fig. 11C) . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Steindachnerina (17)
15a: Dorsal portion of body with 8-11 dark vertical bars. 
Bars subdivided into vertically aligned series of spots in 
some individuals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . Curimata vittata (Kner, 1858) (Fig. 9B)
15b: dorsal portion of body lacking dark vertical bars or 
series of vertically aligned spots . . . . . . . . . . . . . . . . . . . (16)
16a: Anteriormost rays of dorsal fin filamentous in all but 
smaller specimens and reaching beyond posterior limit of 
adipose fin in largest individuals. Upper lip narrow, distance 
from tip of snout to midsagittal margin of lip approximately 
one-half distance from symphysis to angle along lip margin 
between premaxilla and maxilla. 32 (rarely 31 or 33) verte-
brae . . . . .Curimata cyprinoides (Linnaeus, 1766) (Fig. 9C)
16b. anteriormost rays of dorsal fin not filamentous even 
in larger specimens. upper lip relatively broad, distance 
from tip of snout to midsagittal margin of lip approximately 
equal to distance from symphysis to angle along lip margin 
between premaxilla and maxilla. 31 vertebrae  . . . . . . . . . . .  
. . . . . . . . . . . . . . . . . Curimata roseni Vari, 1989 (Fig. 10C)
17a: Prepelvic region of body distinctly flattened transverse-
ly. Five scales across flattened area immediately anterior to 
pelvic-fin origin. anus distinctly separated from anterior 
limit of anal fin by five or six scales  . . . . . . . . . . . . . . . . . . .  
. Steindachnerina planiventris Vari & Vari, 1989 (Fig. 10D)
17b: Prepelvic region of body transversely rounded or at 
most obtusely flattened. Three to four scales across obtuse-
ly rounded area immediately anterior to pelvic-fin origin. 
Anus separated from anterior limit of anal fin by one to three 
scales . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (18) 
18a: Dorsal fin with spot of dark pigmentation on basal por-
tions of middle rays. 30-36 scales present in lateral line to 
hypural joint (only known within Guianas from extreme 
northwestern Guyana) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . Steindachnerina guentheri (Eigenmann & Eigenmann, 
1889) (Fig. 10G)
Figure 12. - Sixth infraorbital. A: Psec-
trogaster amazonica, USNM 261518, 
106.0mm SL. b: Curimata cypri-
noides, uSNM 267964, 125.0 mm SL. 
c: Potamorhina altamazonica, uSNM 
257367, 119.8 mm SL. d: Steindachne-
rina conspersa, USNM 232224, 83.2 
mm SL. Reprinted with permission 
from Vari 1992a.
SidlauSkaS & Vari Anostomoid diversity in the Guianas
Cybium 2012, 36(1) 91
18b: Dorsal fin lacking spot of dark pigmentation on basal 
portions of middle rays. 36-40 scales present in lateral line to 
hypural joint  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . Steindachnerina varii G?ry, Planquette & Le Bail, 1991 
(Fig. 10H) 
Comments on Curimatidae from Guyana, Suriname and 
French Guiana
Species of the Curimatidae constitute the second most 
diverse assemblage of anostomoids in the Guianas (19 mor-
phospecies). Identification of members of the Curimatidae to 
the generic level is complicated by the fact that the delimiting 
characters for some genera involve details of the development 
of the fleshy lining of the roof of the mouth. The pronounced 
elaboration of the fleshy tissues in this region diagnostic of 
some genera in the Guianas (Curimata, Steindachnerina) is 
not present in smaller specimens of those groups. This renders 
identifications of small individuals difficult in the absence of 
ontogenetic series that include adult specimens through pro-
gressively smaller individuals lacking the fleshy elaboration 
of the roof of the mouth present in larger conspecifics. Com-
ments on certain other problematic components of the family 
follow, and additional discussion of curimatid diversity in the 
Guianas appears in Vari et al. (2012).
Curimatella. - although adults of Curimatella have the 
caudal fin lobes broadly enveloped by scales distinctly 
smaller than those on the body, the extent of the scale fields 
is less extensive in smaller specimens making it difficult 
to unambiguously assign such individuals to the genus in 
isolation. Ontogenetic series are often the only recourse in 
such situations. Some species of Cyphocharax, including 
C. microcephalus of the Guianas, have fields of scales of 
about the same size as those on the body extending onto the 
midbasal portions of each fin lobe in a parabolic pattern (for 
comparable condition in a congener see Vari et al., 2010, 
Fig. 2). This pattern in these species of Cyphocharax differs 
from that in the species of Curimatella in which the scales 
on the caudal-fin lobes are proportionally much smaller and 
extend over a greater portion of the lobes (e.g., Curimatella 
alburna, see Vari, 1992a, Fig. 23). 
Cyphocharax helleri and C. spilurus. - Couplet 13 in 
the above key readily distinguishes these two species when 
pigmentation patterns are apparent. However, C. helleri 
demons trates a pronounced range in the intensity of the char-
acteristic series of dark longitudinal stripes along the junc-
tions of the scale rows with this variation perhaps a func-
tion of different water types. When the striping pattern is 
less intense it may be overlooked and such samples might be 
mistakenly identified as C. spilurus. The two species differ 
in the form of the dark spot on the rear of the caudal pedun-
cle and base of the middle caudal-fin rays (typically more 
vertically extensive in C. helleri) and in the typical presence 
in C. spilurus of a field of dark pigmentation at the base of 
the exposed portion of the scales on the lateral and dorsal 
portions of the body contra the lack of such pigmentation in 
C. helleri. The two species also differ in overall body form 
(compare panels E and F of Fig. 9, or figs 15-17 of C. helleri 
versus figs 76-78 of C. spilurus in Vari, 1992b), with C. hel-
leri typically the deeper bodied of the two species (Fig. 15). 
a diagnosis based on body depth is, however, confounded 
by allometric variation in C. helleri, which decreases in pro-
portional body depth over the course of ontogeny and con-
verges on the upper extreme that typifies C. spilurus. Thus, 
body depth only provides a reliable diagnosis for individuals 
below 70 mm SL (see couplet 13 in the key above). 
interestingly, weakly pigmented members of C. helleri 
and particularly deep-bodied members of C. spilurus appear 
to be common among examined specimens from the river 
systems of Suriname. Both of these species occur through-
out Guyana, Suriname and French Guiana, but C. spilurus is 
more common in western drainages, while C. helleri is more 
common to the east (appendix Fig. 20). The complementary 
east-west gradient in the distribution patterns combined with 
the high frequency of individuals with a somewhat interme-
diate morphology suggests that hybridization and introgres-
Figure 13. - Fourth and fifth infraorbitals 
and dorsal portion of third infraorbital. 
A: Psectrogaster curviventris, uSNM 
243221, 72.9 mm SL. b: Potamorhina 
altamazonica, USNM257367, 119.8 
mm SL. c: Curimatella meyeri, uSNM 
26508, 100.1 mm SL. Reprinted with 
permission from Vari 1992a. 
Anostomoid diversity in the Guianas  SidlauSkaS & Vari
92 Cybium 2012, 36(1)
sion may occur between these species. a future genetic study 
should address this possibility directly. 
Curimata. - Two of the species of Curimata (C. roseni, C. 
vittata) in the area of interest are broadly distributed through 
the Amazon River system (see Vari, 1989b: figs. 20, 25) with 
their occurrence in the Guianas limited to the upper portion 
of the Rio Branco system, the adjacent Rupununi River, the 
central Essequibo, and in the case of C. roseni, the demerara 
River (appendix Fig. 16). Similarly, this study revealed that 
the common amazonian species Cyphocharax leucostictus 
and Steindachnerina planiventris also occur in the Branco 
and Rupununi rivers of Guyana (Appendix Figs 19, 23). 
it is likely that the occurrence of these four species in the 
Essequibo basin is a result of their past movement from the 
Figure 14. - Curimatidae. A: Cyphocharax festivus (preserved), 
USNM 280426, 62.6 mm SL, Peru, Loreto, R?o Nanay, NE 
of iquitos. b: Cyphocharax gouldingi (preserved, holotype), 
MZUSP 41762, Brazil, Amap?, Rio Cupix?, 0?40?N, 51?40?W. c: 
Cyphocharax leucostictus (preserved), USNM 268020, 75.1 mm 
SL, Brazil, amazonas, Rio Negro, anavilhanas. d: Cyphocharax 
microcephalus (preserved), ZMA 106.815, Suriname, Marowijne 
Kreek, 63 km S of Afobaka. e: Cyphocharax punctatus (preserved, 
holotype), uSNM 275000, 25.9 mm SL, Suriname, Marowijne 
District, Litani River 03.183?N, 54.200?W. Scale bars indicate one 
centimetre. Photos by T. B. Griswold. 
Figure 15. - Relationship of body depth at dorsal fin origin to stand-
ard length (SL) over ontogeny in Cyphocharax helleri (crosses, 
N = 11) and C. spilurus (circles, N = 34). Trendlines indicate least-
squares linear regressions. 
Figure 16. - Prochilodontidae. A: Semaprochilodus varii (live). 
ANSP 187435. Suriname, Sipalawini, Lawa River, Marowini 
drainage, 03.325?N, 54.063?W. b: Prochilodus rubrotaeniatus 
(preserved), USNM 3768707, 123.7 mm SL, Guyana, Morai Creek. 
Scale bars indicate one centimetre. Photos by M. Sabaj P?rez (a) 
and S. Raredon (B). 
SidlauSkaS & Vari Anostomoid diversity in the Guianas
Cybium 2012, 36(1) 93
upper Rio Branco system into the adjacent portions of the 
Rupununi River basin during flood conditions which result 
in continuity of those two river systems across the Rupununi 
savannahs (Lowe-McConnell, 1964; Lujan and armbruster, 
2011; de Souza et al., 2012). interestingly, no samples of 
Curimata roseni, Curimata vittata, Cyphocharax leucostic-
tus or Steindachnerina planiventris from the Rupununi or 
Essequibo system were known to have been collected until 
recent decades. This admittedly may be a function of earlier 
incomplete sampling of that ichthyofauna or failure of such 
specimens to come to our notice, but may also indicate that 
these species are relatively recent additions to the fish fauna 
of the upper Rupununi and Essequibo rivers. 
Steindachnerina. - One of the species of the Curimatidae 
in our listing, Steindachnerina guentheri, is limited in the 
Guianas to the extreme northwestern portion of Guyana 
in the arau, Barama and Waini river systems (appendix 
Fig. 23). These rivers all drain northwest into the delta of the 
R?o Orinoco, a basin through which S. guentheri is broadly 
distributed (Vari, 1991, Fig. 30).
Key to Prochilodontidae from Guyana, Suriname and 
French Guiana
1a: Caudal fin with series of irregular vertical bars or wavy 
lines formed by small dark spots, but without distinct stripes 
across lobes. Scales between posterior terminus of dorsal-fin 
base and adipose-fin origin comparable in form to adjacent 
scales and lacking membranous spatulate process along pos-
terior margin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. .Prochilodus rubrotaeniatus Jardine & Schomburgk, 1841 
(Fig. 16B)
1b: Caudal fin with total of seven to 14 distinct dark stripes, 
one stripe along middle caudal-fin rays, three to six oblique 
stripes on upper lobe and three to seven oblique stripes on 
lower lobe. Scales between posterior terminus of dorsal-fin 
base and adipose-fin origin with membranous spatulate proc-
ess along posterior margin of scale . . . Semaprochilodus (2)
2a: Membranous opercular border and exposed surface of 
pectoral girdle intensely pigmented with black. Lateral-line 
scales 47-53, circumpeduncular scales 18-22 . . . . . . . . . . . .
. . . . . . . . . . Semaprochilodus varii Castro, 1988 (Fig. 16A)
2b: Membranous opercular border and exposed surface of 
pectoral girdle weakly pigmented with black. Lateral-line 
scales 39-41; circumpeduncular scales 16. Known in the 
Guianas from a single specimen from extreme southwestern 
Guyana (Rio Branco drainage) . . . . . . . . . . . . . . . . . . . . . . .
. . Semaprochilodus insignis (Jardine & Schomburgk, 1841) 
(not figured)
Comments on Prochilodontidae from Guyana, Suriname 
and French Guiana
Only two species of the Prochilodontidae (Prochilodus 
rubrotaeniatus, Semaprochilodus varii) are major compo-
nents of the ichthyofauna in the Guianas. Both are easily 
identified by differences in pigmentation (Fig. 16). Prochi-
lodus rubrotaeniatus is nearly ubiquitous throughout the 
region and found in the Essequibo, Corantijn, Marowijne, 
Oyapock rivers and intervening systems while Semaprochi-
lodus varii is endemic to the Marowijne/Maroni drainage 
(Appendix Fig. 24). A single specimen (AUM 36944) of 
Semaprochilodus insignis is known from the Rio Branco 
drainage in extreme southwestern Guyana. That species is 
widespread through the major portions of the amazon basin 
including the Rio Branco (Castro and Vari, 2004, Fig. 61). 
discUssion
Distributions and endemicity
Fifty-six anostomoid species are currently known to 
inhabit the river systems of the Guianas. This is a remarkably 
high number representing about 20% of the total diversity of 
that superfamily, despite the fact that the Guianas span only 
6% of the total geographic area inhabited by the clade. Fac-
tors potentially contributing to this diversity include: the iso-
lation of the north-flowing drainage systems from each other 
and to a considerable although not absolute degree from the 
neighbouring amazon and Orinoco systems, historical fac-
tors such as the very long term stability of the underlying 
Guiana Shield, an exceptional diversity of habitats, and per-
haps chance (Vari and Ferraris, 2009; Lujan and armbruster, 
2011).
Of the four anostomoid families, the anostomidae with 
30 species is most diverse in this region, followed by the 
Curimatidae (19 species), Chilodontidae (4 species) and 
Prochilodontidae (3 species). Distribution maps for 54 
of these species appear in the appendix, with Abramites 
hypselonotus and Pseudanos trimaculatus not plotted 
because their occurrence in the Guianas is known only from 
single specimens with indefinite collection localities in the 
Rio Branco system in southwestern Guyana. While some 
species are nearly ubiquitous throughout the region (e.g. 
Prochilodus rubrotaeniatus, Leporinus fasciatus, L. granti, 
Cyphocharax helleri, C. spilurus), most have more restric-
ted distributions. inspection of species distribution limits 
reveals six regions harbouring distinct faunas: 1) the Takutu 
and ireng rivers of southwestern Guyana, which form part of 
the upper Rio Branco drainage, which is in turn part of the 
Negro-amazonas system 2) the Barima and Waini rivers of 
northwestern Guyana, which are tributaries to the R?o Ori-
noco delta, 3) the Essequibo-Rupununi River system (inclu-
ding the separately draining demerara and Berbice  rivers) of 
Anostomoid diversity in the Guianas  SidlauSkaS & Vari
94 Cybium 2012, 36(1)
Guyana, 4) a union of the Corantijn, Nickerie, Coppename, 
Saramacca and Suriname river drainages in Guyana and 
Suriname, 5) the Marowijne/Maroni River system of Suri-
name and French Guiana (including the Litani, Tapanahony 
and Mana rivers), and 6) the Oyapock and approuague river 
basins of French Guiana. Of these, the first two are peri-
pheral to the core Guianas and form part of much larger river 
drainages in neighbouring Venezuela (R?o Orinoco) and 
Brazil (Rio amazonas), while the remaining four drai nage 
systems lie entirely or largely within the three targeted coun-
tries (Fig. 1). 
Of the four core faunistic regions in the Guianas, the 
greater Essequibo River system contains the highest number 
of anostomoid species (35), followed by the Maroni and 
associated rivers (22 species), the Corantijn and associated 
rivers (19 species) and the Oyapock-approuague region (14 
species). However, the vast majority (27 of 35) of the anos-
tomoid species inhabiting the Essequibo system also occur 
in the neighbouring Rio Branco (part of the amazon basin), 
with many of these restricted to the river systems of the 
Rupununi savannahs, to which they likely dispersed during 
seasonal inundations (Lowe-McConnell, 1964; Lujan and 
armbruster, 2011; de Souza et al., 2012). if one excludes 
these species of probable amazonian origin, the resulting 
pattern of anostomoid species richness is much more con-
stant across the Guianas. Eight remaining species inhabit the 
Essequibo system, ten in the Corantijn and associated rivers, 
14 in the Maroni drainage, and ten in the Oyapock. 
Many of these truly Guianese species occur in more than 
one of the major faunal regions, but several are endemic 
to only one. Only the Corantijn, Suriname and intervening 
 rivers harbour Leporinus apollo and Petulanos spiloclistron. 
Cyphocharax biocellatus, C. punctatus, Leporinus lebaili 
and Semaprochilodus varii are unique to the greater Maro-
ni system, and Leporinus melanostictus is limited to the 
Oyapock and approuague systems. interestingly, there are 
no species in our sample endemic to the Essequibo (Anosto-
moides laticeps and Leporinus arcus appear to be so on the 
distribution maps but are also known from the R?o Orinoco 
of Venezuela, and in the former case, from the Rio Solim?es 
of Brazil). The numbers of species endemic to a single region 
may increase once revisionary studies are undertaken on the 
several nominal species revealed to have disjunct distribu-
tions (Anostomus ternetzi, Leporinus nijsseni, Leporinus 
granti and possibly Schizodon fasciatus and Curimatopsis 
crypticus) or substantial morphological variation across a 
broad putative range (Anostomus anostomus, Cyphocharax 
helleri). 
New records
This survey revealed four newly recorded species in the 
Guianas, yielding a 8% increase in known species richness 
for this group in the three countries combined. Two of these 
represent species new to science, one of which is described 
in this volume as Cyphocharax biocellatus, and the other 
of which (Leporinus apollo) was described very recent-
ly (Sidlauskas et al., 2011). The other two new records, 
Cyphocharax leucostictus and Steindachnerina planiventris 
of the Curimatidae, represent species that are common in 
the Rio Branco of Brazil and are now recorded within the 
ireng and Takutu river systems of southern Guyana and/or 
the waterways of the Rupununi savannah. Five other species 
(Abramites hypselonotus and Pseudanos trimaculatus of the 
anostomidae, Curimata vittata and C. roseni of the Curima-
tidae and Semaprochilodus insignis of the Prochilodontidae) 
had previously been recorded from Guyana in general terms 
in a recent checklist (Vari et al., 2009), but are now tied to 
specific localities. The known specimens of Abramites 
hypselonotus, Pseudanos trimaculatus and Semaprochilodus 
insignis from Guyana occur only in the Rio Branco drain-
age and represent perhaps the most northeasterly records of 
these species in the Rio Branco basin. The other four species 
discussed above occur within the Essequibo-Rupununi sys-
tem proper, with the two species of Curimata found further 
afield in the Essequibo system than Cyphocharax leucostic-
tus and Steindachnerina planiventris (appendix Figs 16, 19, 
23). Whether this greater range indicates an earlier transi-
tion through the Rupununi portal, higher vagility, different 
habitat tolerances or pure chance is not known. Sabaj et al. 
(2008), citing McConnell (1959), discussed the possibility 
of a Paleogene (23 mya) stream capture of the Rio Takutu 
by the Rio Branco as another possible explanation for the 
co-occurrence of channel-dwelling species such as Rhinodo-
ras armbrusteri in both systems. adults of Curimata species 
also dwell in main channel habitats, but if such an ancient 
dispersal scenario were responsible for their presence in both 
systems we would expect those species to be more broadly 
distributed throughout the Essequibo basin, and to have been 
long ago collected there. instead, the specimens of the four 
new records within the Essequibo were all collected in recent 
decades. The recency of these collections implies that these 
species are new immigrants to Guyana, but it is still possible 
that the range extensions simply result from increased sam-
pling effort.
Unsampled regions
The synthesis of nearly 3000 lots of georeferenced muse-
um anostomoid specimens provides a very detailed sum-
mary of historic ichthyological collecting efforts within the 
lowlands of the Guianas (Fig. 2). While some river systems, 
such as the Essequibo, Rupununi and Lower Corantijn, have 
been sampled very extensively, as have all major drainages 
of French Guiana (the latter thanks to the exhaustive efforts 
reported by Planquette et al. [1996]), other regions have 
never been sampled or have been sampled very sparsely. 
Of the apparent lacunae in Fig. 2, the Berbice, Cuyuni and 
SidlauSkaS & Vari Anostomoid diversity in the Guianas
Cybium 2012, 36(1) 95
Maza runi rivers in Guyana have all been sampled too recent-
ly to have been included in this publication (with specimens 
deposited at the university of Guyana, the Royal Ontario 
Museum, National Museum of Natural History and Oregon 
State university). The remaining regions most in need of 
ichthyological exploration include the Rewa and New rivers 
of southeastern Guyana, the upper Corantijn and Tapanaho-
ny rivers of southern Suriname which are yet to be sampled, 
and possibly the rivers of northwestern Guyana (R?o Ori-
noco drainage) which do not appear to have been surveyed 
ichthyologically since the 1930s. 
Concluding remarks
despite more than 250 years of ichthyological explora-
tion, the many rivers of the Guianas continue to yield new 
discoveries, and we surely have not yet catalogued fully the 
extraordinary diversity of the fishes in that region. Neverthe-
less, thanks to the long and sustained interest in the Guianas, 
the world?s ichthyological collections hold a formidable 
sum of accumulated knowledge about the biogeography and 
diversity of the fishes in that region. This contribution set out 
to aggregate the large amount of available data on one impor-
tant clade in the Characiformes in order to clarify taxonomic 
and geographic boundaries and provide identification keys 
and distribution maps as a service to other ichthyologists. 
This process revealed new species, new records, major gaps 
in historic collecting effort, disjunct distributions that may 
indicate the presence of cryptic species, possible evidence of 
hybridization between two congeneric species, and evidence 
for six distinct regions of endemicity within the fishes of the 
Guianas. These unexpected results provide another good 
example of the power of aggregate data to yield insights unat-
tainable from the data in isolation (for an extended discus-
sion, see Sidlauskas et al., 2010). We hope that specialists on 
the other components of the rich biodiversity of the Guianas 
that are yet to be examined in comparable detail will follow 
our lead and synthesize the available information in their 
realm of expertise. if enough such stu dies can be completed, 
the depth and detail of the resulting picture of diversity and 
distribution could revolutionize our ability to study, conserve 
and understand one of the world?s richest biotas. 
Acknowledgements. - We thank Clint Epps and Caren Barcelo for 
providing assistance with arcMap and arcCatalog, Paulo Petry for 
providing hydrological data layers, Jonathan armbruster, Whit-
comb Bronaugh, T. Britt Griswold, Sahnzi Moyers, Mark Sabaj 
P?rez and Sandra Raredon for photographs and Rapha?l Covain and 
Sonia Fisch-Muller for support and data. Barbara Brown (aMNH), 
Jonathan armbruster (auM), dave Werneke (auM), Mark Sabaj 
P?rez (aNSP), kyle Luckenbill (aNSP), Jeffrey Clayton (uSNM), 
Lisa Palmer (uSNM), Sandra Raredon (uSNM), Mary anne Rog-
ers (FMNH), kevin Swagel (FMNH) and Phil Willink (FMNH) 
provided support at various institutions. Jan Mol and Ren? dekker 
hosted RPV at RMNH. Trina Roberts provided several helpful sug-
gestions concerning GiS and georeferencing. Particular thanks are 
due to Philippe keith, Pierre-Yves Le Bail and iNRa-MNHN for 
providing GPS coordinates for the data that appear in Planquette et 
al. (1996). We thank Mark Sabaj P?rez and an anonymous reviewer 
for comments that improved this manuscript substantially. Support 
for the collecting expedition to the Cuyuni River of Guyana that 
produced several live photos appearing herein was graciously pro-
vided by the Smithsonian institution?s Biological diversity of the 
Guiana Shield Program. 
reFerences
BiRiNdELLi J.L.O. & BRiTSki H.a., 2009. - New species of the 
genus Leporinus agassiz (Characiformes: anostomidae) from 
the rio Curu?, rio Xingu basin, Serra do Cachimbo, Brazil, with 
comments on Leporinus reticulatus. Neotrop. Ichthyol., 7: 1-9.
BLOCH M.E., 1794. - Naturgeschichte der ausl?ndischen Fische. 
Vol. 8. iv + 174 p., pls. 361-396 p. Berlin.
BOROdiN N.a., 1929. - Notes on some species and subspecies of 
the genus Leporinus Spix. Mem. Mus. Comp. Zool., 50: 269-
290, pls. 261-217.
BRITSKI H.A. & BIRINDELLI J.L.O., 2008. - Description of a 
new species of the genus Leporinus Spix (Characiformes: 
anostomidae) from the rio araguaia, Brazil, with comments on 
the taxonomy and distribution of L. parae and L. lacustris. Neo-
trop. Ichthyol., 6: 45-51.
BRiTSki H.a. & GaRaVELLO J.C., 2005. - uma nova esp?cie 
de Leporinus Agassiz, 1829, da bacia Amaz?nica (Ostariophy-
si: Characiformes: anostomidae). Comun. Mus. Ci?nc. Tecnol. 
PUCRS, S?r. Zool., Porto Alegre, 18: 75-83.
CaSTRO R.M.C. & VaRi R.P., 2004. - detritivores of the South 
American fish family Prochilodontidae (Teleostei: Ostariophy-
si: Characiformes): a phylogenetic and revisionary study. 
Smithson. Contrib. Zool., 622: 1-190.
CUVIER G. & VALENCIENNES A., 1850. - Histoire naturelle des 
poissons. Tome vingt-deuxi?me. Suite du livre vingt-deuxi?me. 
Suite de la famille des Salmono?des. Vol. 22. xx + 1 + 532 + 
591 p., pls 634-650 p. Paris and Strasbourg: Ch. Pitois & V. 
Levrault.
dE SOuZa L.S., aRMBRuSTER J.W. & WERNEkE d.C., 2012. 
- The influence of the Rupununi portal on distribution of fresh-
water fish in the Rupununi district, Guyana. Cybium, 36(1): 
31-43.
ENVIRONMENTAL SYSTEMS RESOURCE INSTITUTE, 2008. 
- ArcMap 9.3. Redlands, California: ESRI.
FOWLER H.W., 1914. - Fishes from the Rupununi River, British 
Guiana. Proc. Acad. Nat. Sci. Philad., 66: 229-284.
GaRaVELLO J.C., 2000. - Two new species of Leporinus Spix 
with a review of the blotched species of the Rio Orinoco system 
and rescription of Leporinus muyscorum Steindachner (Charac-
iformes: anostomidae). Proc. Acad. Nat. Sci. Philad., 150: 
193-201.
GARAVELLO J.C. & BRITSKI H.A., 2003. - Family Anostomi-
dae. In: Check List of the Freshwater Fishes of South and Cen-
tral america (Reis R.E., kullander S.O. & Ferraris C.J., Jr., 
eds), pp. 71-84. Porto Alegre, Brazil: Edipucrs.
G?RY J., 1977. - Characoids of the World. 672 p. Neptune City: 
TFH Publications.
G?RY J., PLANQUETTE P. & LE BAIL P.Y., 1988. - Nomencla-
ture des esp?ces du groupe Leporinus maculatus et formes aff-
ines des Guyanes (Pisces, Characoidei, anostomidae). Rev. 
Suisse Zool., 95: 699-713.
Anostomoid diversity in the Guianas  SidlauSkaS & Vari
96 Cybium 2012, 36(1)
INGE R.F., 1956. - Notes on a collection of fishes from southeast-
ern Venezuela. Fieldiana, 34: 425-440.
ISBR?CKER I.J.H. & NIJSSEN H., 1988. - Review of the South 
American characiform fish genus Chilodus, with description of 
a new species, C. gracilis (Pisces, Characiformes, Chilodonti-
dae). Beaufortia, 38: 47-56.
LINNAEUS C., 1758. - Systema naturae per regna tria naturae, 
secundum classes, ordines, genera, species, cum characteribus, 
differentiis, synonymis, locis. Editio decimal, reformata. Tomus 
I. Holmiae. ii + 824 p.
LOWE-MCCONNELL R.H., 1964. - The fishes of the Rupununi 
savanna district of British Guiana, Pt. i. Ecological groupings 
of fish species and effects of the seasonal cycle on the fish. 
Zool. J. Linn. Soc., 45: 103-144.
LuJaN N.k. & aRMBRuSTER J.W., 2011. - The Guiana Shield. 
In: Historical Biogeography of Neotropical Freshwater Fishes 
(albert J.S. & Reis R.E., eds), pp. 211-224. Berkeley: The 
Regents of the univ. of California.
MauTaRi k.C. & MENEZES N.a., 2006. - Revision of the South 
american freshwater genus Laemolyta Cope, 1872 (Ostario-
physi: Characiformes: anostomidae). Neotrop. Ichthyol., 4: 
27-44.
McCONNELL R.B., 1959. - Fossils in the north savannas and their 
significance in the search for oil in British Guiana. Timehri, J. 
R. Agric. Com. Soc. Br. Guiana, 38: 65-85.
OVCHYNNYk M.M., 1971. - unrecorded and new species of 
fishes from fresh waters of Ecuador. Zool. Anz., 187: 82-122.
PLANQUETTE P., KEITH P. & LE BAIL P.Y., 1996. - Atlas des 
Poissons d?eau douce de Guyane. Tome 1. 429 p. Collection 
Patrimoine Nat., 22. Paris: iEGB-MNHN, iNRa, CSP, Min. 
Environ.
REIS R.E., KULLANDER S.O. & FERRARIS C.J. Jr., 2003. - 
Check List of the Freshwater Fishes of South and Central 
america. 742 p. Porto alegre, Brasil: Edipucrs.
SABAJ M.H., TAPHORN D.C. & CASTILLO G.O.E., 2008. - Two 
new species of thicklip thornycats, genus Rhinodoras (Tele-
ostei: Siluriformes: doradidae). Copeia, 2008: 209-226.
SABAJ P?REZ M.H., 2009. - Photographic atlas of fishes of the 
Guiana Shield. Bull. Biol. Soc. Wash., 17: 52-59.
SANTOS Dos G.M., 1980. - Aspectos de sistem?tica e morfolog?a 
de Schizodon fasciatus Agassiz 1829, Rhytiodus microlepis 
Kner 1859 e Rhytiodus argenteofuscus Kner, 1829 (Ostei-
chthyes, Characoidei, anostomidae) do Lago Janauac?-ama-
zonas. Acta Amazonica, 10: 635-649.
SANTOS Dos G.M., 1981. - Estudo da alimenta??o e h?bitos ali-
mentares de Schizodon fasciatus Agassiz, 1829, Rhytiodus 
microlepis Kner, 1859, e R. argenteofuscus Kner, 1859 do Lago 
Janauac?-aM (Osteichthyes, Characoidei, anostomidae). Acta 
Amazonica, 11: 267-283.
SaNTOS dos G.M. & ZuaNON J., 2006. - Anostomoides pas-
sionis, a new fish species from Rio Xingu, Brasil (Characi-
formes: anostomidae). Zootaxa, 1168: 59-68.
SANTOS Dos G.M. & ZUANON J., 2008. - Leporinus amazoni-
cus, a new anostomid species from the amazon lowlands, Bra-
zil (Osteichthyes: Characiformes). Zootaxa, 1815: 35-42.
SCHaRCaNSkY a. & LuCENa C.a.S.d., 2007. - Caenotropus 
schizodon, a new chilodontid fish from the Rio Tapaj?s drain-
age, Brazil (Ostariophysi: Characiformes: Chilodontidae). 
Zootaxa, 1557: 59-66.
SidLauSkaS B. & SaNTOS dos G.M., 2005. - Pseudanos win-
terbottomi, a new anostomine species (Teleostei: Characi-
formes: anostomidae) from Venezuela and Brazil, and com-
ments on its phylogenetic relationships. Copeia, 2005: 109-
123.
SIDLAUSKAS B. & VARI R.P., 2008. - Phylogenetic relationships 
within the South American fish family Anostomidae (Teleostei, 
Ostariophysi, Characiformes). Zool. J. Linn. Soc., 154: 70-210.
SidLauSkaS B., GaRaVELLO J.C. & JELLEN J., 2007. - a 
new Schizodon (Characiformes: Anostomidae) from the R?o 
Orinoco system, with a redescription of S. isognathus from the 
Rio Paraguay system. Copeia, 2007: 711-725.
SidLauSkaS B., GaNaPaTHY G., HaZkaNi-COVO E., 
JENkiNS k.P., LaPP H., MCCaLL L.W., PRiCE S., SCHER-
LE R., SPaETH P.a. & kidd d.M., 2010. - Linking big: the 
continuing promise of evolutionary synthesis. Evolution, 64: 
871-880.
SidLauSkaS B., MOL J. & VaRi R.P., 2011. - dealing with 
allometry in linear and geometric morphometrics: a taxonomic 
case study in the Leporinus cylindriformis group (Characi-
formes: anostomidae) with description of a new species from 
Suriname. Zool. J. Linn. Soc.: 103-130.
SPIX J.B. & AGASSIZ L., 1829. - Selecta genera et species Pis-
cium quos in itinere per Brazilian annis 1817-1820; Peracto et 
pigendus curavit dr. J.B. de Spix... digessit descripsit et obser-
vationibus anatomicis illustravit dr. L. agassiz. [Memoriae J.B. 
de Spix] xvi, 1-6. 438 + 495 plates p. Munich: Typis C. Wolf.
TaYLOR B.W., FLECkER a.S. & HaLL R.O., 2006. - Loss of a 
harvested fish species disrupts carbon flow in a diverse tropical 
river. Science, 313: 833-836.
VARI R.P., 1982. - Systematics of the Neotropical characoid genus 
Curimatopsis (Pisces, Characoidei). Smithson. Contrib. Zool.: 
373: 1-28.
VARI R.P., 1983. - Phylogenetic relationships of the families 
Curimatidae, Prochilodontidae, anostomidae, and Chilodonti-
dae (Pisces: Characiformes). Smithson. Contrib. Zool.: 378: 
1-60.
VARI R.P., 1989a. - A phylogenetic study of the Neotropical 
characiform family Curimatidae (Pisces: Ostariophysi). Smith-
son. Contrib. Zool.: 471: 1-71.
VARI R.P., 1989b. - Systematics of the Neotropical characiform 
genus Curimata Bosc (Pisces: Characiformes). Smithson. Con-
trib. Zool.: 474: 1-63.
VARI R.P., 1989c. - Systematics of the Neotropical characiform 
genus Psectrogaster Eigenmann and Eigenmann (Pisces: 
Characiformes). Smithson. Contrib. Zool.: 1-43.
VARI R.P., 1989d. - Systematics of the Neotropical characiform 
genus Pseudocurimata Fern?ndez-Y?pez (Pisces: Ostariophy-
si). Smithson. Contrib. Zool., 490: 1-28.
VaRi R.P., 1991. - Systematics of the Neotropical characiform 
genus Steindachnerina Fowler (Pisces: Ostariophysi). Smith-
son. Contrib. Zool., 507: 1-118.
VaRi R.P., 1992a. - Systematics of the Neotropical characiform 
genus Curimatella Eigenmann and Eigenmann (Pisces: Ostari-
ophysi) with summary comments on the Curimatidae. Smith-
son. Contrib. Zool., 533: 1-48.
VaRi R.P., 1992b. - Systematics of the Neotropical characiform 
genus Cyphocharax Fowler (Pisces: Ostariophysi). Smithson. 
Contrib. Zool., 529: 1-137.
VaRi R.P. & CHaNG F., 2006. - Cyphocharax derhami, a new 
species (Ostariophysi: Characiformes: Curimatidae) from 
northeastern Peru. Ichthyol. Explor. Freshw., 17: 93-96.
SidlauSkaS & Vari Anostomoid diversity in the Guianas
Cybium 2012, 36(1) 97
VaRi R.P. & FERRaRiS C.J. Jr., 2009. - Fishes of the Guiana 
Shield. Bull. Biol. Soc. Wash., 17: 5-18.
VARI R.P. & WILLIAMS A.M., 1987. - Headstanders of the Neo-
tropical anostomid genus Abramites (Pisces: Characiformes: 
anostomidae). Proc. Biol. Soc. Wash., 100: 89-103.
VaRi R.P., CaSTRO R.M.C. & RaREdON S.J., 1995. - The Neo-
tropical fish family Chilodontidae (Teleostei: Characiformes): 
a phylogenetic study and a revision of Caenotropus G?nther. 
Smithson. Contrib. Zool., 577: 1-32.
VaRi R.P., FERRaRiS C.J. Jr., RadOSaVLJEViC a. & FuNk 
V.a., 2009. - Checklist of the Freshwater Fishes of the Guiana 
Shield. Bull. Biol. Soc. Wash., 17: 1-95.
VaRi R.P., ZaNaTa a.M. & CaMLiER P., 2010. - New species 
of Cyphocharax (Ostariophysi; Characiformes; Curimatidae) 
from Rio de Contas drainage, Bahia, Brazil. Copeia, 2010: 382-
387.
VaRi R.P., SidLauSkaS B.L. & LE BaiL P.Y., 2012. - New spe-
cies of Cyphocharax (Ostariophysi: Characiformes: Curimati-
dae) from Suriname and French Guiana and a discussion of 
curimatid diversity on the Guiana Shield. Cybium, 36(1): 
63-69.
WaTkiNS G., SauL W., HOLM E., WaTSON C., aRJOON d. & 
BICKNELL J., 2005. - The fish fauna of the Iwokrama Forest. 
Proc. Acad. Nat. Sci. Philad., 154: 39-53.
WINTERBOTTOM R., 1980. - Systematics, osteology and phylo-
genetic relationships of fishes of the ostariophysan subfamily 
anostominae (Characoidei, anostomidae). Life Sci. Contrib. R. 
Ontario Mus., 123: 1-112.
Anostomoid diversity in the Guianas  SidlauSkaS & Vari
98 Cybium 2012, 36(1)
appendix Figure 1. - distribution map of Anostomoides laticeps 
(circles), Leporinus nijsseni (triangles) and Synaptolaemus cingu-
latus (cross).
appendix Figure 2. - distribution map of Anostomus anostomus 
(circles), A. brevior (triangles) and A. ternetzi (crosses).
Appendix Figure 3. - Distribution map of Hypomasticus despaxi 
(triangles) and H. megalepis (circles).
appendix Figure 4. - distribution map of Laemolyta proxima (cir-
cles), Leporinus apollo (crosses) and Leporinus melanostictus (tri-
angles).
Appendix
SidlauSkaS & Vari Anostomoid diversity in the Guianas
Cybium 2012, 36(1) 99
appendix Figure 5. - distribution map of Leporellus vittatus (cross-
es), Leporinus arcus (triangles) and Leporinus gossei (circles).
appendix Figure 6. - distribution map of Leporinus fasciatus (cir-
cles). 
appendix Figure 7. - distribution map of Leporinus maculatus 
(circles) and L. desmotes (crosses).
Appendix Figure 8. - Distribution map of Leporinus nigrotaeniatus 
(triangles) and L. ortomaculatus (circles).
Anostomoid diversity in the Guianas  SidlauSkaS & Vari
100 Cybium 2012, 36(1)
appendix Figure 9. - distribution map of Leporinus agassizi (cir-
cles) and L. friderici (triangles).
appendix Figure 10. - distribution map of Leporinus granti (cir-
cles). 
appendix Figure 11. - distribution map of Leporinus lebaili (tri-
angles) and Pseudanos irinae (circles).
appendix Figure 12. - distribution map of Petulanos plicatus (tri-
angles) and P. spiloclistron (circles).
SidlauSkaS & Vari Anostomoid diversity in the Guianas
Cybium 2012, 36(1) 101
Appendix Figure 13. - Distribution map of Schizodon fasciatus 
(circles) and S. vittatus (triangles).
appendix Figure 14. - distribution map of Caenotropus labyrinthi-
cus (triangles) and C. maculosus (circles).
appendix Figure 15. - distribution map of Chilodus punctatus (cir-
cles) and C. zunevei (triangles).
appendix Figure 16. - distribution map of Curimata cyprinoides 
(circles), C. roseni (crosses) and C. vittata (triangles).
Anostomoid diversity in the Guianas  SidlauSkaS & Vari
102 Cybium 2012, 36(1)
appendix Figure 17. - distribution map of Curimatella alburna 
(circles), Curimatella immaculata (crosses) and Cyphocharax 
punctatus (triangles).
Appendix Figure 18. - Distribution map of Curimatopsis crypticus 
(triangles) and Cyphocharax biocellatus (circles).
appendix Figure 19. - distribution map of Cyphocharax leucostic-
tus (triangles) and C. microcephalus (circles).
appendix Figure 20. - distribution map of Cyphocharax helleri 
(crosses) and C. spilurus (circles).
SidlauSkaS & Vari Anostomoid diversity in the Guianas
Cybium 2012, 36(1) 103
appendix Figure 21. - distribution map of Cyphocharax festivus 
(circles).
appendix Figure 22. - distribution map of Cyphocharax gould-
ingi (triangles), Psectrogaster ciliata (circles) and P. essequibensis 
(crosses).
Appendix Figure 23. - Distribution map of Steindachnerina guen-
theri (crosses), S. planiventris (triangles) and S. varii (circles).
appendix Figure 24. - distribution map of Prochilodus rubrotae-
niatus (crosses), Semaprochilodus insignis (triangle) and Semap-
rochilodus varii (circles)