Cyphocharax oenas Vari 1992

Cyphocharax oenas

DIAGNOSIS.—Cyphocharax oenas is distinguished from its congeners by the combination of 29 to 32 lateral-line scales to the hypural joint, the development of pores along the entire lateral line in all but juveniles, the 29 to 31, typically 30 vertebrae, the relative body depth (0.32–0.40 of SL), the relative depth of the caudal peduncle (0.14–0.15 of SL), the relative length of the postorbital portion of head (0.38–0.43 of HL), the relative length of the head (0.32–0.36 of SL), the relative width of the orbit (0.31–0.35 of HL), the absence of multiple series of longitudinal dark stripes or small dark spots in longitudinal rows on the body, the absence of a discrete patch of dark pigmentation on the dorsal fin, the presence of a rotund patch of dark pigmentation about one-half the diameter of the orbit on the midlateral surface of the caudal peduncle, the presence of a relatively discrete border on the spot and the absence of secondary pigmentation fields reaching to the dorsal and ventral margins of the caudal peduncle in juveniles, the absence of 4 or 5 large midlateral dark spots on the body, the absence of a stripe of dark pigmentation across the middle rays of the caudal fin in moderate to large-sized specimens, the lack of a reticulate pattern on the body in adults, and the possession of 9 branched dorsal-fin rays.

DESCRIPTION.—Body moderately elongate, moderately compressed laterally. Dorsal profile of head very slightly convex from margin of upper lip to vertical line through anterior margin of anterior nostril, straight from that line to tip of supraoccipital spine. Dorsal profile of body nearly straight or very slightly convex from tip of supraoccipital spine to about four scales anterior of origin of dorsal fin, slightly convex from that point to origin of dorsal fin; straight and slightly posteroventrally slanted at base of dorsal fin, straight from rear of dorsal fin to base of adipose fin and from rear of base of adipose fin to caudal peduncle. Dorsal surface of body somewhat to distinctly flattened in region proximate to supraoccipital spine and posteriorly from tip of spine to approximately four scales anterior of dorsal fin origin; with distinct median keel immediately anterior to dorsal fin, smoothly rounded transversely posterior to fin. Ventral profile of body gently curved from tip of lower jaw to caudal peduncle. Prepelvic region somewhat flattened, with median series of scales in region proximate to insertion of pelvic fins; scales anterior to median series irregularly arranged; scales on prepelvic region comparable in size to those on adjoining regions of body. Very obtuse median keel posterior to pelvic fin origin; secondary keels not evident on each side of postpelvic portion of body.

Greatest body depth at origin of dorsal fin, depth 0.32–0.40 [0.40]; snout tip to origin of dorsal fin 0.51–0.54 [0.51]; snout tip to origin of anal fin 0.84–0.87 [0.84]; snout tip to origin of pelvic fin 0.56–0.60 [0.57]; snout tip to anus 0.79–0.83 [0.79]; origin of dorsal fin to hypural joint 0.54–0.58 [0.54]. Distal margin of dorsal fin slightly rounded; last unbranched and first branched rays about three to three and one-half times length of ultimate ray. Distal margin of pectoral fin rounded; length of pectoral fin 0.20–0.24 [0.20], fin tip extends to or falls slightly short of vertical line through origin of pelvic fin. Distal margin of pelvic fin rounded; length of pelvic fin 0.21–0.24 [0.21], reaches to origin of anal fin in smaller individuals, falls slightly short of fin or reaches only to anus in largest specimens examined. Caudal fin forked. Adipose fin well developed. Distal margin of anal fin emarginate, anteriormost branched rays about two and one-half times length of ultimate ray. Least depth of caudal peduncle 0.14–0.15 [0.14].

Head profile distinctly pointed overall; head length 0.32–0.36 [0.32]; upper and lower jaws equal, mouth terminal; snout pointed, snout length 0.25–0.30 [0.30]; nostrils of each side very close, anterior circular, posterior crescent-shaped with aperture partially closed by thin flap of skin separating nares; orbital diameter 0.31–0.35 [0.32]; adipose eyelid present, weakly developed, with broad vertically ovoid opening over center of eye; length of postorbital portion of head 0.38–0.43 [0.39]; gape width 0.24–0.28 [0.26]; interorbital width 0.40–0.45 [0.41].

Pored lateral-line scales from supracleithrum to hypural joint 29 to 32 [30]; all scales of lateral line pored, canals in lateral-line scales straight; 3 or 4 series of scales extend beyond hypural joint onto caudal-fin base; 5 to 6 [5] scales in transverse series from origin of dorsal fin to lateral line; 4 or 5 [4] scales in transverse series from lateral line to origin of anal fin.

Dorsal-fin rays ii,9 [ii,9]; anal-fin rays ii,7 [ii,7]; pectoral-fin rays 13 to 15 [14]; pelvic-fin rays i,7 or i,8 (i,7 rare) [i,8].

Total vertebrae 29 (7), 30 (55), 31 (2).

COLOR IN ALCOHOL.—Available specimens all largely lacking guanine on scales; overall ground coloration ranging from light tan to light brown; ground coloration within populations constant. Darker specimens with upper lip, snout, dorsal portion, of head and upper half of opercle covered by field of small, very dark chromatophores. Same portions of head and particularly upper lip, covered by field of less dense chromatophores in lighter individuals. Darker individuals with posterior margins of scales outlined by narrow band of small dark chromatophores; this pigmentation faint or absent in members of lighter colored populations. Center of scales dorsal of lateral line distinctly darker in all populations. Diffuse deep-lying midlateral stripe extending from supracleithrum to caudal peduncle in all populations. Patch of dark superficial chromatophores on midlateral surface of posterior portion of caudal peduncle, spot ranging from rotund to slightly horizontally elongate, with distinct margins and no secondary field of chromatophores extending ventral and dorsal of central spot to dorsal and ventral margins of caudal peduncle in juveniles. Fin-rays of dorsal, caudal, and anal fins outlined by series of small, dark chromatophores in all populations; intensity of pigmentation more pronounced in darker individuals. Adipose fin dusky. Pectoral and pelvic fins hyaline in lightly pigmented individuals, with some dark pigmentation along margin of fin rays in individuals with darker overall pigmentation.

DISTRIBUTION.—Central and eastern portion of the Río Orinoco basin (Figure 92).

ETYMOLOGY.—The species name, oenas, from the Greek for wild pigeon or dove, in reference to the name of the type locality, Paloma, which is Castilian for pigeon or dove.

TYPE MATERIAL EXAMINED.—21 specimens (21, 31.2–47.6).

HOLOTYPE.—VENEZUELA. Territorio Federal Delta Amacuro: Secondary caño off Caño Paloma, 92 nautical miles from sea buoy (8°28′00′N, 61°25′36″W), collected by D.J. Stewart et al., 21 Nov 1979, MBUCV V-20336, 1 (44.1).

PARATYPES.—VENEZUELA. Territorio Federal Delta Amacuro: Secondary caño off Caño Paloma, 92 nautical miles from sea buoy (8°28′00″N, 61°25′36″W), collected with holotype, USNM 235485, 10 (33.3–47.6; 1 specimen cleared and counterstained for cartilage and bone); MBUCV V-20337, 10 (31.2–47.4).

NON-TYPE MATERIAL EXAMINED.—453 specimens (28, 29.5–52.7)

VENEZUELA. Territorio Federal Delta Amacuro: Secondary caño off caño Paloma, 92 nautical miles from sea buoy (8°28′00″N, 61°25′36″W), collected with holotype, USNM 309287, 168; MBUCV V-20338, 168. First small caño on W side of Caño Paloma, 100 m above its mouth, 92 nautical miles from sea buoy (approx. 8°29′N, 61°25′W), USNM 235486, 3; USNM 235465, 1; USNM 235503, 2. Small caño at mouth of Caño Fiscal, 64 nautical miles from sea buoy (approx. 8°32′N, 61°02′W), USNM 235482, 2. Río Orinoco, small caño and marsh on S shore, 83 nautical miles from sea buoy, USNM 235487, 6; MBUCV V-20339, 6. Río Orinoco, Laguna on Isla Tortola, 134 nautical miles upstream from sea buoy (approx. 8°41′N, 62°03′W), USNM 235509, 3. Small caño tributary to caño Araguao, 112 nautical miles upstream from sea buoy (approx. 8°38′N, 61°43′W), USNM 235483, 21 (10, 33.2–37.9); MBUCV V-20340, 22. Cove on sand bar near E end of Isla Portuguesa, 117 nautical miles from sea buoy (approx. 8°36′N, 61°48′W), USNM 235476, 14 (9, 32.2–40.3); MBUCV V-20341, 14. Monagas: Río Orinoco, 161 nautical miles upstream from sea buoy, Laguna Tapatapa on Isla Tapatapa, near downstream end of Caño Limón (approx. 8°32′N, 62°26′W), USNM 235510, 1. Isolated pools on Cocos, small island on N side of river, opposite Los Castillos, between Puerto Ordaz and Barrancas (8°30′42″N, 62°26′06″W), USNM 235477, 2. Río Orinoco, Barrancas, Laguna El Guatero, 143 nautical miles upstream from sea buoy (approx. 8°41′N, 62°11′W), USNM 235481, 2; USNM 235444, 6. Bolívar: Río Orocopiche, about 15 m from mouth in Río Orinoco, downstream from Rt. 19 bridge (approx. 8°03′N, 63°40′W), USNM 235496, 1. Río Aro, about 3 km downstream from Rt. 19 bridge, about 85 km from Ciudad Bolívar (approx. 8°00′N, 64°15′W), USNM 235495, 2. Guarico: Río Guariquito, at government reserve, ESE of Calabozo (approx. 8°35′N, 67°15′W), USNM 257527, 9 (29.5–52.7).

Phylogenetic Comments

Diverse body systems demonstrate discrete variation in the Curimatidae. These features have been the source of a great deal of information pertinent to the elucidation of the hypothesized phylogenetic relationships of and within the family (Vari, 1982a, 1983, 1984a, 1989a, b, c, d). One exception to that generalization is the subject of this study, the genus Cyphocharax. In his analysis of phylogenetic relationships in the Curimatidae, Vari (1989a) was unable to identify any synapomorphies supporting the hypothesis that Cyphocharax as defined therein was monophyletic. The anatomical studies associated with this study have been similarly unsuccessful in identifying any uniquely derived features indicating that the species of Cyphocharax share a common, exclusive evolutionary history. The lack of a derived defining feature for Cyphocharax in conjunction with the multitomy between that genus, Curimatella, Steindachnerina, and Pseudocurimata (Vari, 1989a) means that no evidence now exists to refute an alternative hypothesis that components of Cyphocharax may be more closely related to one or more of the other genera in that multitomy than to the remaining species of Cyphocharax (see also comments under “Remarks” under discussion of Cyphocharax).

Vari (1989a:58–59) tentatively identified some possible groupings in Cyphocharax largely based on data from two systems, head and body pigmentation, and reductive features of the laterosensory canal system and associated canal-bearing bones. Modifications of the systems remain the most informative phylogenetically among the various anatomical features studied, albeit providing an incomplete and somewhat contradictory picture. Although variation exists in various other body systems, the range of differences in such systems within Cyphocharax is typically relatively limited compared with the situation in other lineages of curimatids. The problems engendered by that lack of diversity are exacerbated by the continuous nature of the variation in many features in Cyphocharax. This typically makes it impossible to non-arbitrarily assign the condition in a particular species to discrete character states.

Many derived changes in both those body systems and others are autapomorphic for particular species. Autapomorphies are uninformative in phylogenetic studies, but are rather pertinent to problems of species definition. Those diverse characters and the evidence for their derived natures are discussed within the appropriate species accounts (e.g., “Autapomorphies of Cyphocharax abramoides”).

PIGMENTATION.—One of the pigmentation patterns noted by Vari (1989a:58–59) within Cyphocharax was the presence of a patch of dark pigmentation on the midlateral surface of the caudal peduncle in ten nominal species and subspecies of the genus, five of which (stigmaturus, esperanzae, ucayalensis, vandeli, and esperanzae pijpersi) are considered synonyms in this study. Over one-half of the recognized species of Cyphocharax (gangamon, gilbert, gillii, gouldingi, helleri, meniscaprorus, mestomyllon, modestus, oenas, pantostictos, punctatus, saladensis, santacatarinae, signatus, spilotus, spiluropsis, spilurus, vanderi, and voga) have a patch of dark pigmentation on the midlateral surface of the caudal peduncle. The form of that pigmentation in this assemblage of 19 species varies from a relatively elongate stripe (e.g., C. pantostictos, Figure 12) to a rotund spot (e.g., C. gillii, Figure 86). Discrete broad patches of dark pigmentation centered on the midlateral surface of the caudal peduncle have a relatively limited distribution within the Curimatidae, and are absent in the Prochilodontidae, the sister group to the Curimatidae. Thus the presence of a patch of dark pigmentation on the midlateral surface of the caudal peduncle is hypothesized to be derived within the family. It is noteworthy that such a pigmentation pattern also occurs in all species of Pseudocurimata (Vari, 1989b), some species of Steindachnerina (Vari, 1991), and in one species of Curimatella (Vari, 1992). The presence of such pigmentation on the caudal peduncle in these outgroups, in particular in all species of Pseudocurimata, in conjunction with the unresolved nature of the relationships of those genera and Cyphocharax (Vari, 1989a) introduces some uncertainty into the hypothesis that the presence of such pigmentation defines a monophyletic assemblage within Cyphocharax. Various combinations of species within the assemblage of 19 species with caudal peduncle pigmentation do, however, share other derived features (see below) lending credence to the hypothesis that components of the assemblage of species with a patch of dark pigmentation constitute a natural assemblage.

A second pigmentation pattern distinctive for a subunit of Cyphocharax is the pattern of dark longitudinal stripes on the lateral and dorsolateral surfaces of the body in C. helleri (Figure 13) and C. multilineatus (Figure 19). Such intense pigmentation positioned along areas where horizontal rows of body scales overlap is unique to these species within the Curimatidae. Thus the feature is hypothesized to represent a derived feature for the two species. The very faint longitudinal stripes in C. microcephalus (Figure 36) may be homologous at a higher level of generality with the intense striping in C. helleri and C. multilineatus. If that is the case then the presence of the longitudinal stripes, either faint or well developed, would be a derived feature common to three species (helleri, multilineatus, and microcephalus).

Two species within the subunit of Cyphocharax with dark pigmentation on the midlateral surface of the caudal peduncle (punctatus and vanderi) also share a distinctive pattern of large dark spots on the midlateral surface of the body (see Figures 43, 45, 46). Although a scattering of small spots on the lateral and dorsolateral surfaces of the body characterizes juveniles and moderate-sized specimens of Cyphocharax voga (see Figures 55, 56) that pigmentation pattern differs notably from the spots in C. punctatus and C. vanderi and represents an evidently non-homologous, albeit autapomorphic, feature. No other species in the Curimatidae has a pigmentation pattern of spots on the midlateral surface of the body comparable to that in C. punctatus and C. vanderi, nor is such a pattern known in the Prochilodontidae. Thus the pigmentation on the body in those two species is considered a synapomorphy for the species pair.

LATEROSENSORY CANAL SYSTEM OF BODY.—The one notable modification of the laterosensory canal system on the body in Cyphocharax is the incomplete poring of the lateral line in three members of the genus (saladensis, vexillapinnus, and punctatus). The homology of the condition in C. punctatus and that in C. vexillapinnus and C. saladensis is questionable. Both C. vexillapinnus and C. saladensis have a relatively constant number of pored scales along the anterior portion of the lateral line scale series (8–9 and 5–8 pored scales respectively) across a relatively broad size range (22.4–63.0 mm SL and 27.7–66.5 mm SL, respectively) that includes adults. The available material of Cyphocharax punctatus, alternatively, demonstrates a pronounced ontogenetic increase in the number of pored scales (8–20 pored out of 27–30 total) across a distinctly smaller size range (18.6–42.5 mm SL). In their description of this latter species, Vari and Nijssen (1986:54) noted that “there is an increase in the number of pored lateral line scales in this species with increasing size. If the species attains a larger maximum size than indicated by the present sample, then it is possible that larger individuals would have a completely pored laterosensory canal system on the body.” None of the subsequently examined specimens of C. punctatus are larger than the type specimens making it impossible to test the hypothesis. Nonetheless various other species of Cyphocharax with completely pored lateral lines as adults undergo a comparable progressive increase in the number of pored scales within the size range of the known specimens of C. punctatus (see also comments on Curimatus (Hemicurimata) esperanzae pijpersi in “Remarks” under Cyphocharax helleri). Such an ontogenetic elaboration of the canal in other species of Cyphocharax makes it likely that the incompletely pored laterosensory system on the body in C. punctatus represents a juvenile condition, and that larger specimens of the species would have completely pored lateral lines. Although it is not possible to confirm that hypothesis in the absence of larger specimens, the available data indicates that the incompletely pored but ontogenetically lengthened lateral line in C. punctatus is not homologous with the invariably truncated lateral line of C. vexillapinnus and C. saladensis. The reduced laterosensory canal system on the body in C. vexillapinnus and C. saladensis is consequently hypothesized to be a homologous derived feature unique for that pair of species in the genus. A reduced laterosensory canal system on the body was hypothesized by Vari (1982a) as synapomorphic for the species of Curimatopsis. As discussed by Vari (1989a:61–63) the common occurrence of these reductive features in the five species of Curimatopsis and the cited subunit of Cyphocharax is hypothesized homoplastic within the context of the overall most parsimonious hypothesis of intergeneric relationships among curimatids.

FIRST INFRAORBITAL (IO1).—In his phylogenetic study of the Curimatidae Vari (1989a:37) noted that the first infraorbital, the most anterior of the ossifications that borders the ventral and posterior margins of the orbit, typically has a discrete tube-like laterosensory canal segment in most characiforms. Such a canal segment is evidently universal to the Prochilodontidae, the sister group to the Curimatidae, and is also typical of the vast majority of species among curimatids in general and Cyphocharax in particular. Such a laterosensory canal segment in IO1 is lacking in only two components of the Curimatidae, all species of Curimatopsis and some species of Cyphocharax. The absence of the canal in the two genera was hypothesized to represent independent losses in the context of the overall most parsimonious hypothesis of relationships in the Curimatidae (Vari, 1989a:37, 60). The lack of a laterosensory canal segment in the first infraorbital in the species of Curimatopsis was proposed as an additional synapomorphy for the species of the genus (Vari, 1989a:54).

Given the broad phylogenetic distribution of a canal in the first infraorbital in the various groups cited above, the presence of an ossified laterosensory canal associated in that bone hypothesized to represent the primitive condition for Cyphocharax. Thus the lack of the structure in nine members of the genus (gangamon, meniscaprorus, nigripinnis, oenas, punctatus, saladensis, signatus, vanderi, vexillapinnus) is hypothesized derived. Although several of the Cyphocharax species (saladensis, vanderi, vexillapinnus) lacking a laterosensory canal segment in the first infraorbital reach a moderate body size, the other six species of the genus lacking that canal (gangamon, meniscaprorus, nigripinnis, oenas, punctatus, signatus) have among the smallest known maximum standard lengths in the genus, and indeed in the family. Among other curimatids only some species of Curimatopsis remain so small as adults. The reduced body sizes of the six noted species of Cyphocharax relative to other members of the genus raises the question of whether the absence of the IO1 canal is perhaps correlated with reduced body length. Weitzman and Vari (1988:445) following Myers (1958:29), noted that one of the paedomorphic morphological features typical of miniature species is the reduction of the laterosensory canal system of the head and body. Such presumably reductive, putatively paedomorphic features occur not only among characiforms, but also in other ostariophysans (e.g., Siluriformes (Schaefer et al., 1989:204)). Although none of the diminutive species of Cyphocharax fall within the size limit for miniatures proposed by Weitzman and Vari (1988), the small body size of the species relative to congeners and other curimatids raises the possibility that we are dealing with independent losses consequent not upon common ancestry but rather reduced body size. This may explain the incongruities that exist between the distribution of the absence of a laterosensory canal segment in the first infraorbital versus other derived features within Cyphocharax (see also discussion below).

SIXTH INFRAORBITAL (IO6).—The sixth infraorbital (the dermosphenotic of some authors) is the dorsal of the typically canal-bearing bones in the infraorbital series and overlies the dilatator fossa on the dorsolateral surface of the neurocranium (see Vari, 1989a, fig. 36). Vari (1989a:39) noted a reduced IO6 in two species of Curimatopsis and the absence of the ossification in the other members of the genus. A similar two-stage reductive trend occurs within Cyphocharax with the sixth infraorbital in C. vexillapinnus and C. gangamon reduced relative to that typical among curimatids and with the ossification absent in C. signatus and C. punctatus. Given the general occurrence of the ossification in outgroups to Cyphocharax both in and outside of the Curimatidae, the reduction and loss of the bone are considered derived features at different levels of universality within Cyphocharax. Within the overall most parsimonious hypothesis of relationships within the Curimatidae (Vari, 1989a) it is assumed that these reductions are homoplasticly manifested in Curimatopsis.

The reduction and loss of the sixth infraorbital in these species of Cyphocharax, three of which (gangamon, signatus, and punctatus) have the shortest known maximum standard lengths in the genus again raises the possibility that we are dealing with a paedomorphic truncation of the developmental sequence of the sixth infraorbital. Alternatively, the presence of a complete IO6 in specimens of other species of Cyphocharax of comparable size to the species under question, renders that generalization less tenable. Indeed specimens of Cyphocharax vanderi comparable in size to the examined cleared and stained specimens of C. vexillapinnus have the sixth infraorbital notably well developed.

SUMMARY.—The detailed characters suggest at best some general groupings within Cyphocharax, but with the evidence demonstrating a high degree of incongruity. The largest subunit of Cyphocharax defined by any discussed characters consists of the 19 species (gangamon, gilbert, gillii, gouldingi, helleri, meniscaprorus, mestomyllon, modestus, oenas, pantostictos, punctatus, saladensis, santacatarinae, signatus, spilotus, spiluropsis, spilurus, vanderi, and voga) having a patch of dark pigmentation on the midlateral surface of the caudal peduncle. Nonetheless, only one of the two other derived features of pigmentation common to more than one species in the genus has a distribution congruent with this grouping. The presence of distinct large dark spots on the midlateral surface of the body at some point in development is unique to C. punctatus and C. vanderi, both members of the 19 species assemblage characterized by the caudal peduncle pigmentation. In contrast, C. helleri, which has a distinct spot on the caudal peduncle, shares a second distinctive feature of body pigmentation, the presence of multiple dark horizontal stripes with C. multilineatus which, however, lacks a patch of dark pigmentation on the caudal peduncle. Similarly C. microcephalus, a species with faint longitudinal striping on the body perhaps homologous with the pigmentation in C. helleri and C. multilineatus (see discussion under “Pigmentation”), also lacks a patch of dark pigment on the caudal peduncle. If both pigmentation features, body striping and a dark patch on the caudal peduncle, are derived, then we are either dealing with homoplasy or secondary loss.

The superimposition of information from the laterosensory canal system of the body complicates the picture further. The derived absence of the laterosensory canal segment in the first infraorbital characterizes both some species with dark caudal peduncle pigmentation (meniscaprorus, oenas, punctatus, saladensis, signatus, vanderi) and some lacking it (vexillapinnus, gangamon, nigripinnis). Similarly, incongruities exist between the distribution across species of the occurrence of pigmentation on the midlateral surface of the caudal peduncle on the one hand, and the pattern of occurrence of the various types of modifications of the infraorbitals (absence of a laterosensory canal segment in the first infraorbital; reduction of loss of the sixth infraorbital) on the other. These incongruities make it premature to propose any hypothesis of phylogenetic relationships in the genus at this time.

Endemic Species

The available information on character polarity and distribution is relatively uninformative as to the phylogenetic relationships within Cyphocharax, a deficiency that also precludes any rigorous comments about the historical biogeography of the genus. It is noteworthy nonetheless that the distributions of approximately 82% of the species of Cyphocharax agree with the areas of endemism noted by Vari (1988). The areas of endemism and their included species

RESUMO

O gênero Cyphocharax Fowler (1906), uma subunidade da família Curimatidae, ordem Characiformes, é aqui revisado. Cyphocharax possui três sinônimos juniores, os gêneros Xyrocharax Fowler (1913), Hemicurimata Myers (1929), e Curimatoides Fowler (1940a). São reconhecidas 33 espécies em Cyphocharax: C. abramoides (Kner, 1859a), amplamente distribuída na bacia do rio Amazonas e tributários meridionais do rio Orinoco; C. aspilos, uma nova espécie, endêmica dos rios da bacia do lago Maracaibo; C. festivus, uma nova espécie, conhecida de várias porções da bacia Amazônica e dos rios das Guianas e leste da Venezuela; C. gangamon, uma nova espécie, do rio Tapajós, na bacia Amazônica; C. gilbert (Quoy & Gaimard, 1824), das drenagens costeiras do Rio de Janeiro até o estado da Bahia, no nordeste do Brasil; C. gillii (Eigenmann & Kennedy, 1903), da bacia do Rio da Prata; C. gouldingi, dos rios do estado do Amapá e também dos rios Capim, Tocantins e Xingu, todos no estado do Pará, Brasil; C. helleri (Steindachner, 1910), do leste da Venezuela, Guianas e parte central do estado do Amapá, no Brasil; C. leucostictus (Eigenmann & Eigenmann, 1889), conhecido da bacia do rio Amazonas e rios costeiros da Amapá, Brasil; C. magdalenae (Steindachner, 1879a), ocorrendo desde o sudoeste da Costa Rica até o sistema do rio Magdalena, no noroeste da Colômbia; C. meniscaprorus, uma nova espécie, do rio Aro, tributário do rio Orinoco, na Venezuela; C. mestomyllon, uma nova espécie, do sistema do rio Negro, no Brasil; C. microcephalus (Eigenmann & Eigenmann, 1889), encontrado em uma série de rios no Suriname e na Guiana; C. modestus (Fenández-Yépez, 1948), endêmica da porção superior da bacia do rio Paraná; C. multilineatus (Myers, 1927), das porções centrais do sistema do rio Amazonas; C. nagelii (Steindachner, 1882), endêmica do rio Paraná superior; C, nigripinnis, uma nova espécie da bacia Amazônica; C. notatus (Steindachner, 1908), amplamente distribuída através da bacia Amazônica; C. oenas, uma nova espécie, da bacia do rio Orinoco; C. pantostictos Vari & Barriga (1990), das porções ocidentais da bacia Amazônica no Equador e Peru; C. platanus (Günther, 1880), da bacia do Rio da Prata, excluindo o rio Paraná superior; C. plumbeus (Eigenmann & Eigenmann, 1889), amplamente distribuída através da bacia Amazônica; C. punctatus (Vari & Nijssen, 1986), endêmica do sistema do rio Marowijne, no Suriname e Guiana Francesca; C. saladensis (Meinken, 1933), das drenagens costeiras do sudeste do Brasil e porções da bacia do Rio da Prata; C. santacatarinae (Femández-Yépez, 1948), dos rios costeiros dos estados brasileiros de Santa Catarina, Paraná e Säo Paulo; C. signatus, urna nova espécie, do sistema do rio Araguaia, estado de Goiás, no Brasil; C. spilotus (Vari, 1987), do sistema do rio Uruguai no sudeste do Brasil e regiöes próximas na Argentina; C. spiluropsis (Eigenmann & Eigenmann, 1889) das porções central e ocidental da bacia Amazônica; C. spilurus (Günther, 1864), do rio Cuyuni na Venezuela e Guiana, rios costeiros da Guiana, Suriname, e Guiana Francesa, porção superior do rio Branco no Brasil e, talvez, sistema do rio Orinoco; C. stilbolepis, uma nova espécie, conhecida somente dos sistemas dos rios Xingu e Tocantins; C. vanderi (Britski, 1980), da bacia do rio Paraná superior; C. vexillapinnus, uma nova espécie, dos cursos médio e superior do rio Amazonas, no Brasil, Peru e Equador, e C. voga (Hensel), dos rios costeiros do estado Rio Grande do Sul e parte sul do estado de Santa Catarina, no Brasil, e também do Uruguai e porções do sistema do Rio da Prata.

Quatorze espécies e subespécies são colocadas corno sinônimos neste estudo. Pseudocurimata steindachnerina Femández-Yépez (1948), baseada em material do sistema do rio Magdalena, é considerada um sinônimo de Cyphocharax magdalenae. Curimatus albula Lütken (1874), do sistema do Rio das Velhas, pertencente à bacia do rio São Francisco, e Pseudocurimata grandocule Femández-Yépez (1948), do estado brasileiro do Espírilo Santo, são considerados sinônimos de Cyphocharax gilbert. Curimata gnaca Azpelicueta & Braga (1988), da região de Resistência, na Argentina, é tentativamente colocada como um sinônimo de Cyphocharax spilotus. Curimatus vandeli Puyo (1943), descrito da Guiana Francesca, e Curimatus (Hemicurimata) esperanzae pijperzi Géry (1965), baseado em espécimes do Suriname, são sinônimos de Cyphocharax helleri. Curimatopsis maculatus Ahl (1934), descrito da Argentina, foi baseado em um juvenil de Cyphocharax voga. Curimatus hermanni Ahl (1931), descrito com base em dois exemplares coletados no rio Capim, no estado brasileiro do Pará, é considerado um sinônimo de Cyphocharax notatus. Curimatus (Curimatella) xinguensis Steindachner (1908), baseado em material do sistema do rio Xingu, é colocado na sinonímia de Cyphocharax leucostictus. Curimatella rehni Fowler (1932), com a série-tipíca proveniente de Mato Grosso, é considerado um sinônimo de Cyphocharax gillii. Curimatus surinamensis Steindachner (1910), baseado em espécimes da porção superior do rio Suriname, no Suriname, é um sinônimo de Cyphocharax spilurus. Curimatus stigmaturus Fowler (1913), descrito do sistema do rio Marañon, no Peru, Curimatoides ucayalensis Fowler (1940a), baseado em um único exemplar da bacia do rio peruario Ucayali, e Curimata esperanzae Myers (1920), baseada em uma série de exemplares juvenis originários da porção superior do rio Madeira, na Bolívia, são todos colocados como sinônimos de Cyphocharax spiluropsis.

Lectótipos são designados para Curimatus albula Lütken, Curimatus (Hemicurimata) esperanzae Myers, Curimatus leucostictus Eigenmann & Eigenmann, Curimatus magdalenae Steindachner, Curimatus microcephalus Eigenmann & Eigenmann, Curimatus platanus Günther, Curimatus plumbeus Eigenmann & Eigenmann, Curimatus spiluropsis Eigenmann & Eigenmann, Curimatus spilurus Günther, e Curimatus voga Hensel.

Porções centrais e do leste na bacia do Orinoco