Revision of the Neotropical genus Triportheus Cope , 1872 ( Characiformes : Characidae )

The genus Triportheus Cope, 1872 is revised and a total of 16 species (including 3 new species) are recognized from most of the major river drainages of South America. Triportheus magdalenae (Steindachner, 1878) is the sole species occurring west of the Andean Cordilleras. Triportheus paranensis (Günther, 1874) is considered a junior synonym of Triportheus nematurus (Kner, 1858) and a new Triportheus species is described for the río Paraguay basin. Chalcinus rotundatus iquitensis Nakashima, 1941 and Chalcinus elongatus iquitensis Nakashima, 1941 are placed into the synonymy of Triportheus albus Cope, 1872 and T. culter (Cope, 1872) respectively. The name Salmo clupeoides employed by Natterer (in Kner, 1860) is considered a nomen nudum. Neotypes are designated for Chalceus angulatus Spix & Agassiz, 1829, Chalceus rotundatus Jardine in Schomburgk, 1841 and Chalcinus auritus Valenciennes in Cuvier & Valenciennes, 1850. Lectotypes are designated for Chalcinus brachipomus Valenciennes in Cuvier & Valenciennes, 1850 and Chalcinus nematurus. Identification keys are provided for the Triportheus species in the major drainage basins of South America.


Introduction
The species of the characid genus Triportheus Cope (1872) inhabit most of the major river drainages of South America, and can be easily recognized by their expanded, keeled coracoids and large pectoral fins.Some species of the genus reach a moderate size (200-240 mm), constituting an important element in both commercial and subsistence fisheries.In the Amazon basin, Triportheus is among the fishes most often consumed by humans (Queiroz & Crampton, 1999).Triportheus species have relatively weak dentition and their usual food items include seeds, plankton, and small invertebrates.In poor oxygenate water, they are able to develop barbels on the lower lips that serve to direct the superficial oxygenate water into the mouth.
The first described species of the genus was Chalceus angulatus proposed by Spix and Agassiz (1829) based on specimens collected by the Spix and Martius expedition in Brazil from 1817 to 1820 (see remarks under that species).The next species to be described, also in Chalceus, was C. rotundatus Jardine (in Schomburgk, 1841).Subsequently, Valenciennes (in Cuvier & Valenciennes 1850), citing the differences between C. angulatus and the other species of Chalceus, created a new genus, Chalcinus, to include Chalceus angulatus and two new species, Chalcinus brachipomus and C. auritus, described in the same publication.Most of the Triportheus species described by subsequent authors were referred to the genus Chalcinus (Table 1).

O F S
The genus Triportheus was created by Cope (1872), with two new species: T. albus Cope, 1872 and T. flavus Cope, 1872.Triportheus albus was subsequently designated as the type species by Jordan (1919:363).Eigenmann (1910:440) designated Chalcinus brachipomus as the type species of Chalcinus and considered Triportheus to be a junior synonym of that genus.Although considering the two genera to be synonyms, Myers (1940:170) suppressed Chalcinus Cuvier & Valenciennes 1850 as a homonym, arguing that the name was preoccupied by Chalcinus Rafinesque 1815 (in Hymenoptera) and resurrected Triportheus to replace Chalcinus Valenciennes.A third generic name, Coscinoxyron, was created by Fowler (1907) to contain a single species, Chalcinus culter Cope, 1872, but it is herein considered a junior synonym of Triportheus.
The higher level relationships of Triportheus were studied by Malabarba (1998), who proposed eight synapomorphies grouping Triportheus with Lignobrycon, and identified four derived characters to diagnose Triportheus: the very short dorsal process of cleithrum terminating just above the dorsal end of the mesocoracoid; the expansion of the upper end of the cleithrum that contacts the upper portion of the mesocoracoid into a small, medially blade-like projection; the anteroventral extension of the anterior margin of the cleithrum to lie just lateral to the ante-rior margin of the coracoid as a bifurcated anterior process; and the branching of the laterosensory canal segment in the lateral line scales.
This paper treats the species-level diversity of the genus Triportheus, with 16 species recognized of which three species described as new.

Material and Methods
Measurements were made with a digital caliper with data recorded to tenths of millimeter.Methods of measuring follow Fink & Weitzman (1974) with some changes.Postorbital distance was measured from the posterior orbit border to the most posterior border of opercle.The distance between the dorsal and adipose fins was taken from the base of the last dorsal-fin ray to the anterior insertion of the adipose fin.Body depth at the pectoral fin was taken at the vertical slightly posterior to the pectoral-fin insertion, where the greatest body depth occurs.Lateral-line scale counts include all scales in the series including those posterior to the hypural joint.The number of branchial gill rakers refers to the count on the lower arm of the first branchial arch.The number of total vertebrae includes the four elements incorporated into the Weberian apparatus and considers the fused PU1 + PU2 as two elements.Vertebral counts were taken from radiographs.Number of scale series on caudal peduncle refers to the num-Table 1. Nominal species assigned to the genus Triportheus and recognized equivalent species according to the results of this study.Nominal species are cited as in the original description and are arranged alphabetically.(*) Type not examined; synonymy based on original description

O F S
ber of scale rows on each side of caudal peduncle excluding middorsal and midventral series.In the counts of fin rays, lowercase roman numerals indicate unbranched rays, and Arabian numerals indicate branched rays.In counts of the branched anal-fin rays, the last two rays that usually meet basally are counted as one ray.Morphometric data of examined specimens are presented in tables associated with each species description.Entries in brackets represent data for the holotype.
In the Examined Material section of each species, data are arranged in the following sequence: country, state (or equivalent), museum catalog number, number of specimens in lot, collection locality with coordinates (when available) in parentheses.Data on collector and date collected are provided only for type materials.Data of the material collected by the Thayer Expedition were updated based on Higuchi (1996).
The following abbreviations for institutions and collections are used: AMNH, American Museum of Natural History, New York; ANSP, Academy of Natural

Diagnosis.
Triportheus is diagnosed from other genera of the Characidae by the derived presence of: (1) a very short dorsal process of cleithrum terminating just above the dorsal limit of the mesocoracoid (versus process of cleithrum distinctly extending beyond the upper margin of the mesocoracoid); (2) the expansion of the upper end of the cleithrum which meets the upper portion of the mesocoracoid as a small median blade-like projection (versus expansion of cleithrum absent); (3) the expansion of anterior margin of the cleithrum anteroventrally to lie just lateral to the anterior margin of the coracoid and forming a bifurcated anterior process (versus anterior process of the cleithrum not bifurcated); and (4) the branching of lateral-line scales one to three times (versus canal tubes single and unbranched).An additional character distinguishing Triportheus is the low number of scales (1)(2) in the transverse series from the pelvic-fin insertion to the lateral line.

Description. Morphometric data of Triportheus angulatus
presented in Table 3. Body deep and compressed laterally.
Greatest body depth located slightly posterior to vertical through insertion of pectoral fin.Dorsal profile of head straight or slightly convex from snout to rear of head.Dorsal profile of body gently curved from rear of head to dorsal-fin origin; posteroventrally slanted from dorsal-fin origin to caudal peduncle; straight along caudal peduncle.Dorsal portion of body slightly keeled.
Ventral profile of head straight from tip of lower lip to anteroventral margin of dentary; straight from that point to isthmus.Ventral profile of body strongly arched from isthmus to pelvic-fin insertion; nearly convex from pelvic-fin insertion to anal-fin insertion; posterodorsally slanted along anal-fin base; slightly concave along caudal peduncle.Prepelvic region greatly expanded vertically and compressed, with well defined keel.
Mouth slightly upturned, with lower jaw longer than upper jaw.Posterior margin of opercle reaching vertical through pectoral-fin insertion.Nostrils of each side close together; anterior opening circular; posterior elongate.
Teeth on premaxilla in 3 rows; teeth of inner row largest.Five or 6 tricuspidate teeth on outer row; outer row teeth arranged along external margin of premaxilla and visible externally.Medial premaxillary tooth row with 2 or 3 tricuspidate teeth.Six or 7 multicuspidate teeth on inner row of premaxilla.Teeth on maxilla 1-3, much smaller than those on premaxilla and tricuspidate.Teeth on lower jaw in 2 rows.Outer row with 4-6 larger teeth, with 5-7 cusps, and decreasing in size posteriorly.Inner row formed by a small conical tooth, slightly curved posteriorly.
Dorsal-fin rays ii,9; anal-fin rays iii,26-31 [28] (mean = 28; n = 67); pectoral-fin rays i, 11-13 [11]; pelvic fin rays i,6.Dorsal-fin margin straight, situated on posterior half of body; base of last dorsal-fin ray situated slightly anterior to, or at, vertical through anal-fin origin; second unbranched and first branched ray longest; following rays slightly decreasing in length.Pectoral fin pointed, tip falling within region from middle to tip of pelvic fin.Anal fin margin straight, first branched anal-fin ray longest; following rays gradually decreasing in length.Margin of caudal fin truncate; median rays extend slightly beyond margin of remainder of fin.Scales present over anterior one third of fin.

Remarks about type-locality and type-specimens.
Triportheus angulatus is the first described species of the genus and its description was based on specimens collected by the Spix and Martius expedition in Brazil between 1817 and 1820.During this period they first traveled north from Rio de Janeiro, crossing tributaries of the upper rio Paraná, rio São Francisco, and several smaller Atlantic drainages prior to their arrival in Belém.From Belém they traveled by boat along a portion of the rio Tocantins and through the rio Amazonas, to the rio Negro and rio Solimões as far west as Benjamin Constant (Papavero, 1971:65-69 and map).Thus, the collecting locality of Chalceus angulatus could be in the São Francisco, Tocantins, or Amazonas basins.Spix & Agassiz (1829:67) cite the collecting locality of the material only as "in Brasiliae aequinoctialis fluviis".The specimens collected by Spix (except those subsequently donated to Agassiz) were housed in Zoologische Staatssammlung München (ZSM) until its destruction during a British bombing raid on the night of 24-25 April 1944 (Kottelat, 1988: 69).Kottelat (1988:84) presents a list of Spix & Agassiz's types still extant in the ZSM, MHNN (Musée d'Histoire Naturelle de Neuchâtel) and MHNG (Musée d'Histoire Naturelle de Geneve).No Chalceus angulatus specimens are included in this list and the types of the species were apparently lost or destroyed.A neotype (MCP 29943) is herein designated for Triportheus angulatus, as a specimen collected in the rio Amazonas basin (Solimões drainage, Amazonas state, Brazil).This is the species that best fits the original description and drawing provided by Agassiz, in terms of general body shape, dorsal-fin position, pectoral-fin length, and anal-fin ray count.

Diagnosis. A deep bodied
Triportheus species that reaches 178 mm of SL (depth at dorsal-fin origin, 29.7-40.1 % SL; depth at pectoral-fin insertion, 34.0-39.9% SL).Triportheus rotundatus can be distinguished from other Triportheus species by the combination of the presence of 2 longitudinal scale rows between the pectoral-fin insertion and ventral keel; the number of gill rakers on the lower limb of first arch (24-32, mean = 27.6,n = 37); the number of branched anal-fin rays (25-29, mean = 27.1, n = 37), and number of lateral line scales (28-35, mean = 32.3, n = 35); the presence of longitudinal dark stripes on the lateral surface of the body; and the median caudal rays developed into a slightly projecting extension.
Description.Morphometric data of Triportheus rotundatus presented in Table 4. Body deep and compressed laterally.Greatest body depth located slightly posterior to vertical through insertion of pectoral fin.Dorsal profile of head straight from snout to rear of head.Dorsal profile of body gently curved from rear of head to dorsal-fin origin; posteroventrally slanted from dorsal-fin origin to caudal peduncle; slightly curved along caudal peduncle.Ventral profile of head straight from tip of lower lip to anteroventral margin of dentary; straight from that point to isthmus.Ventral profile of body arched from isthmus to pelvic-fin insertion; nearly convex from pelvic-fin insertion to anal-fin origin; posterodorsally slanted along anal-fin base; slightly concave along caudal peduncle.Prepelvic region very expanded and compressed, with well defined keel.
Head blunted in profile; posterior margin of opercle not reaching pectoral-fin insertion.Mouth terminal; slightly upturned.Nostrils of each side close together; anterior opening circular; posterior elongate.
Teeth on premaxilla in 3 rows; teeth of inner row largest.Four or 5 tricuspidate teeth in outer row; outer row teeth positioned along external margin of mouth and can be seen externally.Middle tooth row with 3 tricuspidate teeth; 6 multicuspidate teeth on inner tooth row.Teeth on maxilla 2, teeth smaller than those on premaxilla and flattened.Teeth on lower jaw in 2 rows, outer row with 5 large anterior teeth, and 6 smaller posterior teeth.Inner row formed of single conical, symphyseal tooth.
Dorsal-fin rays ii,9; anal-fin rays iii, 25-29 [27] (mean = 27.1, n = 37); pectoral-fin rays i, 11-13 [11] (mean = 11.5, n = 36); pelvic fin rays i,6.Dorsal-fin margin straight, situated on posterior one half of body; last dorsal-fin ray located at vertical through base of third or fourth branched anal-fin ray; first branched ray longest; following rays slightly decreasing in length.Pectoral fin pointed, tip extending to region falling between middle and tip of pelvic fin.Anal fin margin straight, first branched anal-fin ray longest; following rays gently decreasing in length.Margin of caudal fin truncate; median rays extend slightly beyond margin of remainder of fin.Scales cover basal one-third of caudal fin.
Remarks about type specimens.Travassos, 1951: 284 Diagnosis.An elongate Triportheus species reaching 219 mm SL (depth at dorsal-fin origin, 24.9-32.4% SL; depth at pectoral-fin insertion, 27.5-34.1 % SL).The presence of 1 longitudinal scale row between the pectoral-fin insertion and the ventral keel distinguish this species from all deep bodied Triportheus species all of which have two longitudinal scale rows between the pectoral-fin insertion and the ventral keel.The combination of the possession of 32-38 lateral line scales, 22-28 branched anal-fin rays, 32-40 gill rakers on the lower limb of first arch distinguishes T. brachipomus from elongate congeners except by T. albus.T. brachipomus is distinguished from T. albus by the length of the postorbital region of the head (36.mean = 39.9,mean = 45.8,n= 30 in T. albus), and the distance from the insertion of posterior Description.Morphometric data for Triportheus brachipomus presented in Table 5. Body elongate and compressed laterally.Greatest body depth located slightly posterior to vertical through pectoral-fin insertion.Dorsal profile of head slightly convex from upper lip to nares; nearly straight from nares to rear of head.Dorsal profile of body gently convex from rear of head to dorsal-fin origin; posteroventrally slanted along dorsal-fin base; straight from posterior end of dorsal fin to caudal peduncle; slightly concave along caudal peduncle.Dorsal portion of body transversely rounded.
Ventral profile of head vertical and straight from dorsal border of lower lip to anteroventral margin of dentary; posteroventrally slanted from that point to joint with quadrate.Ventral profile of body distinctly convex from isthmus to pelvic-fin insertion; nearly straight from that point to anal-fin insertion; posterodorsally slanted along anal-fin base; slightly concave along caudal peduncle.Prepelvic region ventrally expanded with midventral keel.
Head obtusely pointed in profile; snout straight in profile.Mouth terminal; lower jaw slightly longer than upper jaw.Nostrils of each side close together; anterior opening circular; posterior kidney-shaped.Eye large, without adipose eyelid.
Premaxillary teeth in 2 rows.Outer row with 5 pentacuspidate teeth and somewhat irregular.Seven teeth on inner row in premaxilla; 2 medial teeth smaller than other teeth in series; teeth of inner row larger.Teeth on maxilla 2-3, smaller than those on premaxilla and tricuspidate.Teeth on lower jaw in two rows, 6 teeth with 5-7 cusps on outer row; inner row with conical symphyseal tooth.

O F S
scale series between lateral line and dorsal-fin origin; 2 scale rows between lateral line and pelvic-fin insertion.Large scale row between pectoral-fin insertion and midventral keel; 12-17 (mean = 14.6, n = 28) scales along mid-dorsal line between tip of supraoccipital spine and dorsal-fin origin.Four rows of scales on caudal peduncle.Dorsal-fin rays ii,9; anal-fin rays iii,22-28 [26] (mean = 24.9,n = 45); pectoral-fin rays i,12-13 [12]; pelvic-fin rays i,6.Dorsal-fin margin straight, dorsal-fin base situated on posterior one-half of body; base of last dorsal-fin ray located anterior to vertical through anal-fin origin.Pectoral fins large and extending posteriorly past one-half length of pelvic fin.First branched anal-fin ray longest; following rays rapidly decreasing in length.Caudal emarginate, nearly forked, scaled only at base.Middle caudal-fin rays extended slightly beyond posterior margin of remainder of fin.

Coloration in alcohol.
Overall ground color yellowish brown.Snout, lower lip, and dorsal portion of head dark.Dorsolateral portion of postorbital region with scattered, small, dark chromatophores.Body with mid-lateral dark stripe extending from supracleithrum posteriorly to caudal peduncle; posterior portion of stripe vertically expanded and broadened into distinctly wider diffuse dark spot on lateral surface of caudal peduncle.Body darker dorsal to stripe.Dark chromatophores forming a diffuse and posterodorsally inclined stripe situated above analfin base.Stripe distinctly separated from anal fin base anteriorly, and approaching base posteriorly.Dorsal and pectoral-fin rays outlined by dark chromatophores.Distal tips of anal-fin rays dark.Caudal-fin rays outlined by series of dark chromatophores.

Description. Morphometric data of Triportheus auritus
presented in Table 6.Body elongate and compressed laterally.Greatest body depth located slightly posterior to vertical through pectoral-fin insertion.Dorsal profile of head slightly convex from upper lip to nares; nearly straight from nares to rear of head.Dorsal profile of body nearly straight from rear of head to dorsal-fin origin; posteroventrally slanted along dorsal-fin base; less inclined from posterior terminus of dorsal fin to caudal peduncle; slightly concave along caudal peduncle.Dorsal portion of body transversely rounded.Ventral profile of head vertically straight from dorsal border of lower lip to anteroventral margin of dentary; straight from that point to joint with quadrate.Ventral profile of body arched from isthmus to pelvic-fin insertion; slightly curved to nearly straight from that point to analfin origin; posterodorsally slanted along anal-fin base; slightly concave along caudal peduncle.Prepelvic region ventrally expanded with midventral keel; kell extending to anal-fin origin.
Head pointed in profile.Mouth terminal; lower jaw as long as upper jaw.Nostrils of each side close together; anterior opening circular; posterior kidney-shaped.Eye large, without adipose eyelid.
Teeth on premaxilla in 3 rows; teeth of inner row larger.Outer row formed by 5 pentacuspidate teeth; middle row with 2 teeth, inner row with 6 teeth.Maxilla with 2-4 teeth, smaller than smallest teeth on premaxilla.Teeth on lower jaw in 2 rows with 5-6 teeth with 5-7 cusps in outer row and inner row consisting of single conical symphyseal tooth.
Scales cycloid, thin, and large.Lateral line distinctly decurved ventrally, completely pored from supracleithrum to base of caudal-fin rays.Forty to 46 [43] (mean = 43.9,n = 36) scales in lateral line; 6 scale series between lateral line and dorsal-fin origin; 2 scale rows between lateral line and pelvic-fin insertion.One large scale row between pectoral-fin insertion and midventral keel; 14-20 [19] (mean = 17.6, n = 31) scales along mid-dorsal line between tip of supraoccipital spine and dorsal-fin origin.Five rows of scales on caudal peduncle.

P R O O F S
Remarks about type-specimens.Cuvier & Valenciennes (1849:263) noted that "[the length of our fish is six pounces.The specimens deposited in the collection of the museum were collected in the Amazon by Mr. Castelnau] (my translation).
No specimens identified as Chalcinus auritus with these data were located in the holdings of MNHN (where the specimens were supposed to belong).A neotype collected in the rio Amazonas drainage (MZUSP 58859, rio Negro, Anavilhanas), is designated herein for Triportheus auritus.That species as defined herein best fits the original description by Valenciennes, in terms of overall body and head shape, and counts of the lateral-line scales and anal-fin rays.
Chalcinus elongatus: holotype, BMNH 1852.9.13:10, no locality.Günther (1864:342) in the original description of Chalcinus elongatus refers to the type-material as being "From the Collection of the Zoological Society" and the distribution as "Hab.-?".A specimen identified as the holotype of Chalcinus elongatus is housed in BMNH (BMNH 1852.9.13:10).Ventral profile of head straight from tip of lower lip to anteroventral margin of dentary; straight from that point to isthmus.Ventral profile of body arched from isthmus to pelvic-fin insertion; nearly convex from pelvic-fin insertion to anal-fin origin; posterodorsally slanted along anal-fin base; slightly curved along caudal peduncle.Prepelvic region ventrally expanded and flattened, with well defined keel.
Head blunt in profile; posterior margin of opercle reaching pectoral-fin insertion.Mouth terminal; lower jaw as long as upper jaw.Nostrils of each side close together; anterior opening circular; posterior elongate.
Gill rakers thin and close together, almost so long as branchial filament length; gill rakers on lower limb of first arch 40-47 .
Teeth on premaxilla in 3 rows; teeth of inner row largest.Five tricuspidate teeth on outer row; outer row teeth arranged along margin of mouth and can be seen externally in closed

P R O O F S
Distribution.Rio Tocantins and rio Araguaia drainages (Fig. 4).
Teeth on premaxilla in 3 rows; teeth of inner row largest.Four to 5 tricuspidate teeth on outer row; outer row teeth arranged along margin of mouth and visible externally in closed mouth.Medial row with 3 tricuspidate teeth.Inner row with 6, rarely 7, multicuspidate teeth.Maxilla with 0-2 flattened teeth smaller than those on premaxilla.Teeth on lower jaw in 2 rows; outer row with 4-5 larger anterior teeth, and 4-6 smaller posterior teeth.Inner row consisting of conical symphyseal tooth.

Coloration in alcohol.
Overall ground color yellowish silvery.Snout and dorsal portion of head dark.Scattered dark chromatophores on opercle and infraorbitals 4-6.Body darker dorsally and on caudal peduncle.Five or 6 sinuous, brown, longitudinal stripes present along scale rows on dorsolateral portion of body.Dark chromatophores distributed over and between rays of all fins.Dorsal-fin rays outlined by dark chromatophores.Middle caudal-fin rays very dark.
Remarks.Two Triportheus species occur in the río La Plata drainage, including the rio Paraná and río Paraguay basins.These can be easily distinguished based on the number of lateral line scales and gill rakers.Two nominal species of Triportheus have been described for this drainage: T. nematurus (Kner, 1858) and T. paranensis (Günther, 1874).These names have been recently applied (Portugal, 1990;Britski et al., 1999;Reis et al., 2003) to the two Triportheus species recognized in the rio Paraná and rio Paraguay.
Triportheus nematurus has been assigned to the form with lower counts of lateral line scales (28-32) and gill rakers (26-33); while T. paranensis has been used for the form with higher counts (34-37 lateral line scales, 38-48 gill rakers).The examination of the type-specimens of Chalcinus nematurus and C. paranensis, however, revealed that both nominal species are based on the form with higher lateral line and gill rakers counts.Since Chalcinus nematurus Kner, 1858 is the oldest available name, Chalcinus paranensis Fowler, 1950 becomes a junior synonym.
As a result, the species with higher lateral line and gill rakers counts referred to as T. paranensis by Portugal (1990), Britski et al. (1999) 9. Body elongate and compressed laterally.Greatest body depth located slightly posterior to vertical through pectoral-fin insertion.Dorsal profile of head convex from upper lip to nares; nearly straight from nares to rear of head.Dorsal profile of body gently convex from rear of head to dorsal-fin origin; posteroventrally slanted along dorsal-fin base; straight from posterior terminus of dorsal-fin base to caudal peduncle; slightly concave along caudal peduncle.Dorsal portion of body transversely rounded.Ventral profile of head vertically straight from dorsal border of lower lip to anteroventral margin of dentary; very slightly convex from that point to isthmus.Ventral profile of body distinctly convex from isthmus to pelvic-fin insertion; nearly straight from that point to anal-fin origin; posterodorsally slanted along anal-fin base; slightly concave along caudal peduncle.Prepelvic region ventrally expanded with midventral keel.

P R O O F S
Head obtusely pointed in profile; snout nearly straight in profile.Mouth terminal; lower jaw equal to upper jaw.Nostrils of each side close together; anterior opening circular; posterior kidney-shaped.Eye large, without adipose eyelid.
Premaxilla with 2 irregular tooth rows.Outer row formed by 5 pentacuspidate teeth.Seven teeth on inner row; 2 medial teeth smaller than other teeth in series.Maxilla with 2-3 tricuspidate teeth all smaller than teeth on premaxilla.Teeth on lower jaw in 2 rows, with 6 teeth of 5-7 cusps on outer row; inner row consisting of conical symphyseal tooth.
Scales cycloid, thin, large.Lateral line distinctly decurved ventrally, completely pored from supracleithrum to base of caudal-fin rays.Thirty-two to 35 (mean = 33.6,n = 75) scales in lateral line (50% of specimens with 34 scales); 5 scale series between lateral line and dorsal-fin origin; 1-2 scale rows from lateral line to pelvic-fin insertion.A series of large scales between pectoral-fin insertion and midventral keel; 9-14 (mean = 11.5, n = 68) scales along mid-dorsal line between tip of supraoccipital process and dorsal-fin origin.Four or 5 rows of scales on caudal peduncle.Dorsal-fin rays ii,9; anal-fin rays iii,24-28 [26] (mean = 25.4,n = 78); pectoral-fin rays i,10-13 [10] (mean = 11.1, n = 78); pelvic-fin rays i,6.Dorsal-fin margin straight, situated on posterior one-half of body; base of last dorsal-fin ray located anterior to vertical through anal-fin origin.Pectoral fin extending over proximal one-third of pelvic fin.Five most anterior branched anal-fin rays much longer than following rays.Caudal fin emarginate or forked; scaled only basally.Middle caudal-fin rays terminate at or slightly beyond posterior margin of remainder of fin.

Coloration in alcohol.
Overall ground color yellowish brown.Body with diffuse, mid-lateral, silver stripe extending posteriorly from supracleithrum to caudal peduncle; stripe expanding vertically posteriorly.Body brownish dorsal to midlateral stripe; light yellow ventral to stripe.Pectoral fin dark pigmented along first rays.Dorsal and anal fin sparsely pigmented with dark chromatophores.Distal tips of anal-fin rays dark.Caudal-fin darkly outlined; series of chromatophores distributed on anterior one-third of caudal-fin rays.

P R O O F S
Type-material remarks.Cope (1872: 264) did not provide a catalog number for the type material of Triportheus albus, but only described it as "total length m..061; length to basis of dorsal fin .0292;from D.I to basis caudal .02"and refers to the type locality as "the Ambyiacu".Subsequently, Fowler (1906:447) listed the type as ANSP 21234.The holotype is a very damaged young specimen lacking the ventral margin of the body.
No type was designated for Chalcinus rotundatus iquitensis by Nakashima (1941) and the synonymy of that species into T. albus in this paper is based on information in the original description, in particular the 31 lateral line scales and 17+35 gill rakers ("branquiespinas").Chalcinus rotundatus iquitensis is an homonym of Chalcinus elongatus iquitensis Nakashima (1941:63) described in the same paper.
The types of Chalcinus knerii could not be located at NMW (H. Wellendorf pers. comm., Feb.1999).The single lot identified as Chalcinus knerii in that collection (NMW 12562-63), is not labeled as type, and contains two specimens, instead of the one described by Steindachner.Although one of these specimens fits the length provided in the original description of C. knerii, it was collected in rio Negro, rather than "Amazonas (bei Teffe?)" as cited in the original description.Nonetheless, some data in the original description (lateral line scales 34, anal-fin rays 29, scale series above lateral line 5) suggests that C. knerii is a junior synonym of Triportheus albus.
Diagnosis.An elongate Triportheus species reaching 245 mm SL (depth at dorsal-fin origin, 20.6-25.9,mean = 22.6% SL, n = 13; depth at pectoral-fin insertion, 23.9-28.5, mean = 26.1% SL, n = 13).The presence of 1 longitudinal scale row between the pectoral-fin insertion and the midventral keel distinguish this species from all deep-bodied Triportheus species all of which that have 2 longitudinal scale rows between the pectoral-fin insertion and the ventral keel.The combination of the number of lateral-line scales (43-47, mean = 45.1, n = 12) and number of gill rakers on the lower limb of the first gill arch (53-83, mean = 70.7,n = 13) distinguishes T. culter from all other elongate-bodied Triportheus species.
Description.Morphometric data for Triportheus culter presented in Table 10.Body elongate and compressed laterally.Greatest body depth located slightly posterior to vertical through pectoral fin insertion.Dorsal profile of head slightly convex from upper lip to nares; slightly slanted, nearly straight from nares to rear of head.Dorsal profile of body gently convex, almost straight from rear of head to dorsal-fin origin; posteroventrally slanted along dorsalfin base; less inclined from posterior terminus of dorsalfin base to caudal peduncle; slightly concave along caudal peduncle.Ventral profile of head vertically straight from dorsal border of lower lip to anteroventral margin of dentary; straight from that point to isthmus.Ventral profile of body arched from isthmus to pelvic-fin insertion; slightly curved to nearly straight from that point to anal-fin origin; posterodorsally slanted along anal-fin base; slightly concave along caudal peduncle.Prepelvic region expanded, with midventral keel.
Head pointed in profile; snout straight, slightly blunted in profile.Mouth terminal; slightly upturned; lower jaw equal to upper jaw.Nostrils of each side close together; anterior opening circular; posterior kidney-shaped.Eye large, without adipose eyelid.Opercle posteriorly expanded, its posterior margin reaching vertical through pectoral-fin insertion.Gill rakers thin and close together, gill-rakers as long as length of branchial filaments; gill rakers on lower limb of first gill arch 53-83 [62] (mean = 70.7,n = 13).

P R O O F S
Teeth on premaxilla in two rows somewhat irregular giving appearance of 3 rows; teeth of inner row larger.Outer row formed by 6 pentacuspidate teeth.Six teeth on inner row; second tooth from symphysis smaller than other teeth in series.Maxilla with 2 teeth smaller than smallest premaxilla tooth.Teeth on lower jaw in two rows, with 5-6 teeth with 5-7 cusps on outer row; inner row consisting of 1 conical symphyseal tooth.

Coloration in alcohol.
Overall ground color yellowish brown.Snout, lower lip, and dorsal portion of head dark.Scattered chromatophores present on all head bones.Body with dark mid-lateral stripe extending posteriorly from supracleithrum to caudal peduncle; stripe becoming diffuse posteriorly and broadened into distinctly wider diffuse dark spot on lateral surface of caudal peduncle.Body darker dorsal to midlateral stripe.All fins outlined by dark chromatophores.Caudal-fin rays outlined by series of chromatophores.

P R O O F S
Type-locality and type-material remarks.Cope (1872:265) did not furnish a catalog number for the type of Chalcinus culter and provided only the following information about that specimen: "Total length .158m.; length to dorsal fin .087, to anal .098."The locality of collection is referred only in the introduction, in a general reference to the fishes listed in his paper.
According to Cope the collection includes fishes from small tributaries of the río Ampiyacu, collected by John Hauxwell, and some additional species collected by Robert Perkins in an expedition from the mouth of rio Negro to the río Ucayali.
The holotype and only specimen used by Cope was subsequently cited as ANSP 16672 by Fowler (1907:450) and Böhlke (1984:45).This specimen is cited as having been collected in Equador ( = Ecuador), by J. Hauxwell, in a locality that is now within Peru.It is a very damaged specimen but has 62 gill rakers (a count typical of T. culter).
No type was designated for Chalcinus elongatus iquitensis Nakashima, 1941.The synonym of the species into Triportheus culter herein is based on combination of characters presented in the description: number of lateral line scales (46) and gill rakers ("branquiespinas", 16+62).

Diagnosis. A deep-bodied
Triportheus species reaching 133.7 mm of SL (depth at dorsal-fin origin, 28.2-37.0,mean = 33.4% SL, n = 26); depth at pectoral-fin insertion, 29.3-34.9,mean = 32.2%SL, n = 25).The presence of 2 longitudinal scale rows between the pectoral-fin insertion and the ventral keel distinguish this species from Triportheus species with elongate bodies that have 1 longitudinal scale row between the pectoral-fin insertion and the ventral keel.Triportheus guentheri differs from all other deep-bodied congeners in the higher number of gill rakers on the lower limb of the first gill arch (52-57, mean = 54.8,n = 26).
Description.Morphometric data for Triportheus guentheri presented in Table 11.Body deep and compressed laterally.Greatest body depth located slightly posterior to vertical through pectoral-fin insertion.Dorsal profile of head very slightly convex from snout to rear of head.Dorsal profile of body gently curved from rear of head to dorsal-fin origin; posteroventrally slanted and slightly convex from dorsalfin origin to caudal peduncle; slightly curved along caudal peduncle.
Ventral profile of head straight from tip of lower lip to anteroventral margin of dentary; slanted from that point to isthmus.Ventral profile of body arched from isthmus to pelvic-fin insertion; slightly convex from pelvic-fin insertion to anal-fin origin; posterodorsally slanted along anal-fin base; slightly curved along caudal peduncle.Prepelvic region very expanded ventrally and flattened, with well developed keel.
Head bluntly rounded in profile; posterior margin of opercle falling short of vertical through pectoral-fin insertion.Snout margin vertically straight.Mouth terminal; lower jaw as long as upper jaw.Nostrils of each side close together; anterior opening circular; posterior elongate.Gill rakers thin and close together, length equivalent to that of branchial filaments; gill rakers on lower limb of first arch 52-57 [50] (mean = 54.8,n = 26).
Teeth on premaxilla in 3 rows; teeth of inner row largest.Four or 5 tricuspidate teeth in outer row; outer row teeth arranged along external margin of mouth and visible externally in closed mouth.Medial tooth row with 3 tricuspidate teeth.Six, rarely 7, multicuspidate teeth on inner row of premaxilla.Maxilla with 0-2 flattened teeth, smaller than those on premaxilla.Teeth on lower jaw in 2 rows.Outer row with 4-5 larger anterior teeth, followed by 4-6 smaller teeth.Inner row consisting of conical symphyseal tooth.
Scales cycloid, thin, large.Lateral line distinctly decurved ventrally, completely pored from supracleithrum to base of caudal-fin rays.Thirty to 33 (mean = 32.1,n = 20) scales in lateral line; 5 scale series above lateral line; 2 scale rows between lateral line and pelvic-fin insertion.Two scale rows between pectoral-fin insertion and midventral keel; 4-5 scale series on caudal peduncle.Scale series along middorsal line irregular, 6-13 scales from supraoccipital process to dorsalfin origin.
Dorsal-fin rays ii,9; anal-fin rays iii,27-32 [29] (mean = 30.5,n = 20); pectoral-fin rays i,11-12 [10]; pelvic-fin rays i,6.Dorsal-fin base situated on posterior one-half of body; base of last dorsal-fin ray located anterior to vertical through anal-fin origin; first branched ray longest with following rays slightly decreasing in length.Pectoral fin pointed, tip reaching vertical through distal one-third of pelvic fin.Anal fin margin straight; first branched anal-fin ray longest; following rays gradually decreasing in length.Margin of caudal fin emarginate; median caudal-fin rays not extended beyond the posterior margin of fin.Scales cover basal onethird of fin.

P R O O F S
Remarks.Garman (1890:4-5) stated that C. brachypomus Günther, 1864 "is so different in essential aspects from that of Valenciennes [C.brachipomus] that the two cannot be considered identical" and consequently that the material reported on by Günther (1864) represented a new species "Chalcinus güntheri".Garman provided a brief diagnosis with counts of the dorsal, anal, and pelvic fins as well as the lateral-line scales (D. 11, A. 28, V. 7, L.l. 34), that seems to be a copy of the description of C. brachypomus by Günther ( 1864).In the description that follows this diagnosis, Garman, however, described a specimen ("Taking one from the San Francisco river as a typical specimen,.Type-material remarks.Garman (1890:1) cited his studied material as having been collected by the Thayer Expedition and deposited in the Museum of Comparative Zoology.Eschmeyer (1998:686) considered three uncatalogued BMNH specimens as syntypes of C. guentheri, which the type-locality as Essequibo and São Francisco based on the argument that Garman did not clearly designate a type.However, T. guentheri was based on one specimen (MCZ 21173) from rio São Francisco ("Taking one from San Francisco river as a typical specimen") and as such the BMNH specimens are not syntypes.Triportheus pictus (Garman, 1890) Fig. 16 Chalcinus pictus Garman, 1890:5 (description, Brazil, Amazonas, rio Jutaí).Triportheus pictus.Fowler, 1950:358 (listed, rio Jutahy) Diagnosis.A deep bodied Triportheus species reaching 107.3 mm of SL (depth at dorsal-fin origin, 34.9-37.1 % SL; depth at pectoral-fin insertion, 35.4-36.6 % SL).The presence of 2 longitudinal scale rows between the pectoral-fin insertion and the ventral keel distinguish this species from elongated body Triportheus species that have 1 longitudinal scale row between the pectoral-fin insertion and the ventral keel.Triportheus pictus differs from all other deep bodied congeners in its lower number of gill rakers on the lower limb of the first gill arch (22-24, mean = 22.8, n = 4), and lower anal-fin ray count (20-21, mean = 20.5, n = 4).
Description.Morphometric data for Triportheus pictus presented in Table 12.Body very deep and compressed laterally.Greatest body depth located slightly posterior to vertical through pectoral-fin insertion.Dorsal profile of head straight from posterior border of premaxilla to rear of head.Dorsal profile of body very slightly convex, almost straight, from rear of head to dorsal-fin origin; posteroventrally slanted from dorsal-fin origin to caudal peduncle; straight along caudal peduncle.
Ventral profile of head somewhat anteriorly curved and then nearly straight to isthmus.Ventral profile of body arched from isthmus to pelvic-fin insertion; slightly curved from pel-vic-fin insertion to anal-fin origin; posterodorsally slanted along anal-fin base; straight along caudal peduncle.Prepelvic region ventrally expanded and flattened, with well developed keel.
Head pointed in profile; snout slightly blunted.Mouth terminal; lower jaw as long as upper jaw.Nostrils of each side close together; anterior opening circular; posterior elongate.Posterior margin of opercle falling short of pectoral-fin insertion.
Teeth on premaxilla in 2 rows; teeth of inner row largest.Five or 6 tricuspidate teeth on outer row and 6 multicuspidate teeth on inner row.Maxilla with 0 to 3 small, tricuspidate teeth.Teeth on lower jaw in 2 rows; outer row with 5 teeth with 5-7 cusps; teeth decreasing in size.Inner dentary tooth row consisting of one conical symphyseal tooth.
Scales cycloid, thin, large.Lateral line distinctly decurved ventrally, completely pored from supracleithrum to base of caudal-fin rays.Thirty to 32 scales in lateral line [32] (mean = 31, n = 4); 5 to 6 scale series above lateral line; 2 scale rows below lateral line.Two scale rows between pectoral fin insertion and midventral keel; 5 scale series on caudal peduncle.Scales along mid-dorsal line 11-13 from supraoccipital process to dorsal-fin origin.
Dorsal-fin rays ii,9; anal-fin rays iii,20-21 [20] (mean = 20.5, n = 4); pectoral-fin rays i,13-14 [13]; pelvic-fin rays i,6.Dorsal fin situated on posterior one-half of body; base of last dorsal-fin ray situated anterior to vertical through analfin origin.Dorsal fin margin straight; first branched ray longest.Pectoral fin pointed, tip reaching to vertical falling in region from middle to tip of pelvic fin.Anal-fin margin straight with first branched anal-fin ray longest and following rays gradually decreasing in length.Margin of caudal fin forked; median rays aligned, and not extending beyond margin of remainder of fin.Scales covering basal one-third of caudal fin.

Coloration in alcohol.
Overall ground color yellowish with silvery regions.Snout, dorsal portion of head and supraorbital regions dark.Some scattered dark chromatophores on opercle and infraorbitals 5 and 6.Longitudinal silver stripe extending from opercle to caudal peduncle.Body dorsal to stripe darkened by chromatophores concentrated in diffuse stripes.Body darker on area above anal-fin base and on peduncle.Pectoral fins strongly pigmented along rays, with more intense pigmentation on first unbranched ray and along fin margin.Dorsal and anal fins slightly outlined by dark chromatophores.Some dark chromatophores outlining anal-fin rays.Caudal fin with diagonal dark stripe extending from caudal peduncle to posterior limit of dorsal caudal fin lobe.
Type-material remarks.In the original description of Chalcinus pictus Garman (1890:1) cited the material as originating from the Thayer Expedition and deposited in the Museum of Comparative Zoology but did not provide a catalog number for the holotype, referring only to "a specimen from Jutahy".One MCZ specimen labeled as Chalcinus pictus and collected by the Thayer expedition in the rio Hyutahy [Jutaí] (MCZ 21261) is considered to be the holotype.Features in this specimen (total length, head length, number of lateral line scales) agree with the information in the original description, in particular the very low number of anal-fin rays (20) typical of T. pictus.Higuchi (1996) cites complete data for the Thayer Expedition rio Jutahy site as: 2°43'S, 66°57'W, Sep-Oct 1865, W. James, S. V. Thayer & Talisman collectors.

Diagnosis.
A deep-bodied Triportheus species reaching 106.8 mm of SL (depth at dorsal-fin origin, 33.5-36.2;depth at pectoral-fin insertion, 35.5-39.5 % SL).The presence of 2 longitudinal scale rows between the pectoral-fin insertion and the ventral keel distinguishes this species from elongate-bodied Triportheus species that have 1 longitudinal scale row between the pectoral-fin insertion and the ventral keel.
Description.Morphometric data of Triportheus curtus presented in Table 13.Body very deep and compressed laterally.Greatest body depth located slightly posterior to vertical through pectoral-fin insertion.Dorsal profile of head straight from margin of premaxilla to rear of head.Dorsal profile of body very slightly convex, from rear of head to dorsal-fin origin; posteroventrally slanted from dorsal-fin origin to caudal peduncle; straight along caudal peduncle.Dorsal portion of body slightly keeled.Ventral profile of head curved from tip of lower lip to isthmus.Ventral profile of body arched from isthmus to pelvic-fin insertion; slightly curved from pelvic-fin insertion to anal-fin origin; posterodorsally slanted along analfin base; straight along caudal peduncle.Prepelvic region very expanded ventrally and flattened, with well developed keel.
Head pointed in profile; snout slightly rounded.Mouth dorsally oriented; lower jaw equals to upper jaw.Nostrils of each side close together; anterior opening circular; posterior elongate.Posterior margin of opercle reaching to vertical through pectoral-fin insertion.

P R O O F S
Gill rakers thick and spaced, length equivalent to three quarters of branchial filament length; gill rakers on lower limb of first arch 23-28 [27-28].
Teeth on premaxilla in 2 rows; teeth of inner row larger.Outer row teeth irregularly arranged with 5 or 6 tricuspidate teeth.Six multicuspidate teeth on inner row in premaxilla.Maxilla with 0 to 3 small, tricuspidate teeth.Teeth on lower jaw in 2 rows, outer row with 5 teeth with 5-7 cusps, tooth size decreasing posteriorly.Inner dentary row consisting of conical, symphyseal tooth.
Dorsal-fin rays ii,9; anal-fin rays iii,24-28 [26-28]; pectoral-fin rays i,11-13 [11]; pelvic-fin rays i,6.Dorsal fin situated on posterior one-half of body; base of last dorsal-fin ray located at vertical line running through base of fourth or fifth branched anal-fin ray; second unbranched and first branched ray longest; following rays gradually decreasing in length.Pectoral fin pointed, reaching vertical falling within area between middle and tip of pelvic fin.Anal-fin margin straight, first branched anal-fin ray longest; following rays gradually decreasing in length.Margin of caudal fin truncate; median rays extended beyond margin of remainder of fin.Scales cover basal one-third of fin.

Coloration in alcohol.
Overall ground color yellowish with silver regions.Some small, dark spots scattered over body.
Two rows of teeth on premaxilla; teeth of inner row larger.Inner tooth row with 7 tricuspidate to pentacuspidate teeth.Outer row with 5 teeth.Maxilla with 0 to 2 teeth smaller than smallest teeth on premaxilla.Dentary with 2 tooth rows; outer row with 7-8 teeth, decreasing in size posteriorly; dentary teeth with 3-5 cusps; inner row consisting of conical symphyseal tooth.
Scales cycloid, thin, and large.Lateral line distinctly decurved ventrally, completely pored from supracleithrum to base of caudal-fin rays.Thirty-eight to 42 scales in lateral line [38][39] (mean = 39.1, n = 47); 6-7 scale series between the lateral line and dorsal fin origin; 2 scale rows from lateral line to pelvic-fin insertion.A large scale present between pectoral-fin insertion and midventral keel; 11-17 [14-17]  Color in alcohol.Overall color of specimens preserved in alcohol silvery yellow.Outline of posterior margin of caudal fin dark.
Remarks.Triportheus magdalenae is the only member of the genus known from the río Magdalena drainage, Colombia.This species demonstrate a large degree of variation in body shape, length of the anal-fin base, and the number of gill rakers.The variation in body shape is apparently associated with sexual dimorphism.Male specimens have a more elongate body (body knife-shape) than females (body fusiform).However, only a few specimens could be dissected to confirm this observation and further analysis is necessary.Nonetheless the variation in body shape does not reveal any patterns that would justify the recognition of more than one species.Although the high number of gill rakers is distinctive for T. magdalenae, this number varies increasing ontogenetically, as shown in Figure 22.
Type-material examined.Type-material remarks.In the original description of Chalcinus magdalenae, Steindachner (1878) did not provide information on the specimens that were the basis of the description nor note a specific type locality, only providing a general locality of "Magdalenen-stromes"( = Río Magdalena) for the several fishes listed in that publication.
In a subsequent paper, Steindachner (1879) provided a detailed description with illustrations, and indicated that the collecting site (1879: 20) of the C. magdalenae was Cienaga.That location is situated in the Colombia coast near the mouth of the río Magdalena (Fig. 23,asterisk).Later, Steindachner (1880:79) provided a list of fishes from the río Cauca and along with a short description of Chalcinus magdalenae " reported on "three specimens of 15-23 cm length".This citation has been misinterpreted by some subsequent authors who cite the río Cauca as the type locality for this species (Eschmeyer, 1998(Eschmeyer, :1001)).There are 15 specimens identified as syntypes of C. magdalenae deposited in NMW (NMW 69151 (7), NMW 69152 (2), NMW 69153 (4), and NMW 69154 (2), Mikschi and Wellendorf, pers. comm., 1999) and one syntype in the ZMC (Nielsen, 1974), all collected in the río Magdalena.Description.Morphometric data for Triportheus pantanensis presented in Table 16.Body deep and compressed laterally.Greatest body depth located slightly posterior to vertical through pectoral-fin insertion.Dorsal profile of head straight from margin of snout to rear of head.Dorsal profile of body gently convex from rear of head to dorsal-fin origin; posteroventrally slanted from dorsal-fin origin to caudal peduncle; and slightly concave along caudal peduncle.Ventral profile of head straight from margin of lower lip to anteroventral margin of dentary; distinctly convex from that point to pelvic-fin insertion; slightly convex from pelvicfin insertion to anal-fin origin; posterodorsally slanted along anal-fin base; straight along caudal peduncle.Prepelvic region distinctly expanded ventrally and laterally flattened, with well developed keel.Teeth on premaxilla in 3 rows with teeth of inner row largest.Four or 5 cusp teeth on outer row, and arranged along external margin of mouth and visible externally in closed mouth.Medial tooth row with 3 tricuspidate teeth.Six, rarely 7, multicuspidate teeth on inner row in premaxilla.Maxilla with 0-2 flattened teeth much smaller than those of premaxilla.Teeth on lower jaw in 2 rows, outer row with 4-5 larger anterior teeth and 4 to 6 smaller posterior teeth.Inner row with conical symphyseal tooth.
Dorsal-fin rays ii,9; anal-fin rays iii,25-30 [29] (mean = 27.9, n = 31); pectoral-fin rays i,10-12 [12]; pelvic-fin rays i,6.Dorsal-fin distal margin straight.Dorsal fin situated on posterior one-half of body.Last dorsal-fin ray located at vertical through base of third or fourth anal-fin ray; first branched ray longest; following rays gradually decreasing in length.Pectoral fin pointed, with tip reaching vertical through distal one-third of pelvic fin.Anal fin margin straight; first branched anal-fin ray longest, following rays gradually decreasing in length.Margin of caudal fin truncate; median rays extending one-half of their length beyond margin of remainder of fin.Scales cover basal onethird of caudal fin.
Etymology.The species name, pantanensis, refers to the Pantanal de Mato Grosso, region where the new species commonly occurs and should be considered in apposition to the genus name.Ventral profile of head straight from margin of lower lip to anteroventral margin of dentary.Ventral profile of body arched from base of dentary to pelvic-fin insertion; nearly straight from that point to anal-fin origin; gently curved along analfin base; straight along caudal peduncle.Prepelvic region distinctly expanded ventrally and laterally flattened, with welldeveloped keel.

O F S
Head blunt in profile; posterior margin of opercle falling short of pectoral-fin insertion.Snout vertically straight.Mouth terminal; lower jaw as longer as upper jaw.Nostrils of each side close together; anterior opening circular; posterior elongate.
Teeth on premaxilla in 3 rows; with teeth of inner row largest.Four to 5 tricuspidate teeth on outer row; outer row teeth arranged along external margin of mouth and visible externally in closed mouth.Medial tooth row with 3 tricuspidate teeth.Seven multicuspidate teeth on inner row of premaxilla.Maxilla with 2-3 tricuspidate teeth smaller than those of premaxilla.Teeth on lower jaw in 2 rows, outer row with 5 larger tricuspidate to pentacuspidate teeth, followed by 3-4 much smaller, tricuspidate teeth.
Scales cycloid, thin, and large.Lateral line distinctly decurved ventrally, completely pored from supracleithrum to base of caudal-fin rays.Thirty-four to 39 [39] (mean = 37.2, n = 31) scales in lateral line; seven scale series between lateral line and dorsal-fin origin; 2 scale rows from lateral line to pelvic-fin insertion.Two scale rows between pectoral-fin insertion and midventral keel; 5 scale series on caudal peduncle.Scales along mid-dorsal line very irregular, with 6-13 [9] (mean = 8.4, n = 17) scales from tip of supraoccipital spine to dorsalfin origin.
Dorsal-fin rays ii,9; anal-fin rays iii,28-32 [29] (mean = 29.9,n = 35); pectoral-fin rays i,10-13 [11] (mean = 11.6,n = 36); pelvic-fin rays i,6.Dorsal-fin margin straight, situated on posterior one-half of body; base of last dorsal-fin ray situated approximately along vertical through base of seventh analfin ray; second unbranched and first branched dorsal-fin ray slightly longer than following rays.Pectoral fin pointed, tip extending posteriorly to vertical through middle of pelvic fin.Anal fin margin slightly curved, first branched anal-fin ray longest, and following rays gradually decreasing in length.Four or five series of scales overlying basal portions of analfin rays, and covering one-half of length of rays.Margin of caudal fin truncate to slightly rounded.Scales covering nearly entire fin.

Coloration in alcohol.
Overall ground color yellowish brown.Snout and dorsal portion of head dark.Some scattered dark chromatophores present on opercle.Body with dark midlateral stripe extending from supracleithrum posteriorly to caudal peduncle; stripe expanding vertically posteriorly and broadened into wider diffuse dark spot on lateral surface of caudal peduncle.Body darker dorsal to stripe.Dorsal-fin rays lightly outlined by dark chromatophores.Scattered chromatophores distributed all over pectoral fin; with more intense pigmentation on first unbranched ray and along fin margin.Caudal-fin border dark.
Etymology.Species name, orinocensis, from the Río Orinoco, where the new species occurs.The name is treated as a name in apposition.The presence of 2 longitudinal scale rows between the pectoralfin insertion and the ventral keel distinguish this species from elongate-bodied Triportheus species that have 1 longitudinal scale row between the pectoral-fin insertion and the ventral keel.Teeth on premaxilla in 3 rows; with teeth of inner row largest.Five tricuspidate teeth of outer row arranged along external margin of mouth and externally visible in closed mouth.Medial row with 3 tricuspidate teeth.Seven multicuspidate teeth on inner row on premaxilla.Maxilla with 2-3 tricuspidate teeth smaller than those on premaxilla.Teeth on lower jaw in 2 rows, outer row with 5 medial teeth, followed by 3-4 much smaller, tricuspidate teeth.Inner row consisting of conical posteriorly curved symphyseal tooth.

Triportheus venezuelensis, new species
Scales cycloid, thin, and large.Lateral line distinctly decurved ventrally, completely pored from supracleithrum to base of caudal-fin rays.Thirty-three to 36 [33] (mean = 34.1,n = 50) scales in lateral line; 5-6 scale series between lateral line and dorsal-fin origin; two scale rows between lateral line and pelvic-fin insertion.Two scale rows between pectoral-fin insertion and midventral keel; 4-5 scale series on caudal peduncle.Scales along mid-dorsal line very irregularly arranged with 6-12 scales from tip of supraoccipital spine to dorsal-fin origin.
Dorsal-fin rays ii,9; anal-fin rays iii,24-27 [25] (mean = 25.6, n = 54); pectoral-fin rays i,10-12 [10] (mean = 11.6,n = 50); pelvic-fin rays i,6.Base of dorsal-fin situated on posterior onehalf of body; base of last dorsal-fin ray located anterior to vertical through anal-fin origin; second unbranched and first branched ray longest with following rays gradually decreasing in length.Pectoral fin pointed with tip extending posteriorly as far as vertical through middle of pelvic fin.Anal-fin margin slightly curved, first branched anal-fin ray longest with following rays gradually decreasing in length.One or 2 series of scale overlaying basal portions of anal-fin rays.Margin of caudal fin truncate with median rays extending for one-half of their length beyond margin of remainder of fin.

Coloration in alcohol.
Overall ground color yellowish brown.Snout and dorsal portion of head dark.Some scattered dark Distribution.Río Orinoco basin (Fig. 12).
Etymology.Species name, venezuelensis, refers to the country drained by Río Orinoco and must be considered in apposition to the genus name

Discussion
The external morphology of the species of Triportheus is markedly similar.The species are so conservative that in some instances it is difficult to find diagnostic characters easily recognizable among some of its components.However, two groups of species can be easily recognized: the elongated (T.albus, T. auritus, T. brachipomus, T. culter, T. magdalenae) and the deep-bodied species (T.angulatus, T. curtus, T. guentheri, T. nematurus, T. orinocensis, T. pantanensis, T. pictus, T. rotundatus, T. signatus, T. trifurcatus and T. venezuelensis).Besides the differences in body depth/standard length proportions, as presented in each diagnosis, the species of each of these groups present different patterns in some characters that further allow the informal recognition of each group.In the elongated species, the scales of one of the scale rows filling the space between the pectoral fin insertion and the midventral keel are distinctly larger than the regular scales covering the body.In the deep-bodied species this space is occupied by two rows of regular sized scales.The pigmented longitudinal sinuous bars (5-6) that usually occur laterally on the body of deep-bodied species, does not exist in the elongated species which usually have only one longitudinal bar from opercle to caudal peduncle.The arrangement of the premaxilary teeth is also different in the two groups.In the deep-bodied species 3 tooth rows are defined (the intermediate row always with less teeth), while in the elongated ones a middle row is not clearly recognizable.Although these characters have not been phylogeneticaly evaluated, the patterns detected above suggest a potential use for relationship studies that deserves to be investigated.
alcohol.Overall ground color yellowish and overlain with guanine.Snout and dorsal region of head scattered dark chromatophores present on opercle and infraorbitals 5 and 6.Body darker dorsally and on analfin base and peduncle.Five or 6 longitudinal brown stripes present on dorsolateral portion of body.Dark chromatophores distributed all over fins.Dorsal fin rays outlined by dark chromatophores.Scattered chromatophores distributed over all of pectoral fin; with more intense pigmentation on first unbranched ray and along fin margin.Some dark chromatophores outlining anal-fin rays.Middle caudal-fin rays very dark.

Fig. 2 .
Fig. 2. Map of central and northern South America showing geographic distribution of Triportheus angulatus (circles; diamond = neotype locality) and T. brachipomus (squares; asterisk = lectotype locality) (some symbols represent more than one locality or lot of specimens).

Fig. 8 .
Fig. 8. Map of central and northern South America showing geographic distribution of Triportheus auritus (circles; asterisk = neotype locality), T. guentheri (black squares; white square = type-locality) and T. curtus (triangle; diamond = syntype-localities) (some symbols represent more than one locality or lot of specimens).Coloration in alcohol.Overall ground color yellowish brown.Snout, lower lip, and dorsal portion of head dark.Scattered dark chromatophores present on all head bones.Body with mid-lateral dark stripe extending from supracleithrum posteriorly to caudal peduncle; stripe becoming diffuse posteriorly and broadened into distinctly wider diffuse dark spot on lateral surface of caudal peduncle.Body darker brown dorsal to midlateral stripe.Dorsal margin of body dark.All fins pigmented along rays.Dorsal and pectoral-fin rays outlined by dark chromatophores.Distal tips of anal-fin rays darker.Caudal-fin rays outlined by series of dark chromatophores.
mouth.Medial row with 3 tricuspidate teeth; inner row with 6 multicuspidate teeth.Maxilla with 2 flattened teeth, smaller than those on premaxilla.Teeth on lower jaw in 2 rows, outer row with 4 smaller teeth posteriorly and 4 larger teeth anteriorly.Inner row consisting of one conical symphyseal tooth.Scales cycloid, thin, large.Lateral line distinctly decurved ventrally, completely pored from supracleithrum to base of caudal-fin rays.Thirty-two to 35 (mean = 33.8,n = 20) scales in lateral line; 5 scale series above lateral line; 2-3 scale rows below lateral line.Two scale rows between pectoral-fin insertion and midventral keel; 4-5 scale series on caudal peduncle.Nine to12 scales (mean = 10.2, n = 20) along mid-dorsal line from supraoccipital process to dorsal-fin origin.Dorsal-fin rays ii,9; anal-fin rays iii-iv, 26-29 (mean = 27.3,n = 24); pectoral-fin rays i,10-12; pelvic-fin rays i,6.Dorsalfin base located on posterior one-half of body with last dorsal-fin ray located at vertical line through base of third or fourth anal-fin ray; first branched ray longest; following rays decreasing slightly in length.Pectoral fin pointed, tip reaching posteriorly to area middle and tip of pelvic fin.Anal-fin margin straight, first branched anal-fin ray longest; following rays gradually decreasing in length.Margin of caudal fin truncate; median rays extend about one-half their length beyond margin of remainder of fin.Scales covering basal one-third of fin.Total vertebrae 37.Coloration in alcohol.Overall ground color yellowish silvery.Snout and dorsal portion of head dark.Scattered dark chromatophores present on opercle and infraorbitals 5 and 6.Body darker dorsally and dorsal to anal-fin base and on caudal peduncle.Five or 6 sinuous, brown, longitudinal stripes present on dorsolateral portion of body.Dark chromatophores distributed over all fins.Dorsal-fin rays outlined by dark chromatophores.Chromatophores distributed over pectoral-fin between the rays; more intense pigmentation present on first unbranched ray.Anal-fin margin darker.Middle caudal-fin rays very dark.
Diagnosis.A deep bodied Triportheus species reaching 159 mm of SL (depth at dorsal-fin origin, 31.9-36.9,mean = 33.6%SL, n = 36; depth at pectoral-fin insertion, mean =  34.9%SL, n = 36).The presence of 2 longitudinal scale rows between the pectoral-fin insertion and ventral keel distinguish this species from elongate bodied Triportheus species that have 1 longitudinal scale row between the pectoral-fin insertion and the ventral keel.Among deep bodied Triportheus species, T. nematurus differs by the combination of the number of gill rakers on the lower limb of the first gill arch (38-48, mean = 42.7,n = 34); the number of lateral-line scales (33-37, mean = 34.2,n = 32); the number of branched anal-fin rays (25-31, mean = 28.5, n = 35); and the presence of longitudinal dark stripes on the lateral surface of the body.Description.Morphometric data for Triportheus nematurus presented in Table8.Body deep and compressed laterally.Greatest body depth located slightly posterior to vertical through pectoral-fin insertion.Dorsal profile of head straight from snout to rear of head.Dorsal profile of body gently curved from rear of head to dorsal-fin origin; posteroventrally slanted from dorsal-fin origin to caudal peduncle; nearly straight along caudal peduncle.Ventral profile of head straight from tip of lower lip to anteroventral margin of dentary; arched from that point to pelvic-fin insertion; nearly straight from pelvic-fin insertion to anal-fin origin; posterodorsally slanted along anal-fin base; straight along caudal peduncle.Prepelvic region very expanded ventrally and flattened, with well developed keel.Head pointed in profile; posterior opercle margin almost reaching vertical through pectoral-fin insertion.Snout somewhat rounded anteriorly.Mouth terminal; lower jaw usually as long as upper jaw, but slightly longer in some specimens.Most specimens with very small barbel at each side of the mouth.Nostrils of each side close together; anterior opening circular; posterior elongate.Gill rakers thin and close together, length equivalent to one-half of branchial filament length; gill rakers on lower portion of first gill arch 38-48 [47] (mean = 42.7,n = 34).
Dorsal-fin rays ii,9; anal-fin rays iii,25-31 [28]  (mean = 28.5, n = 35); pectoral-fin rays i,10-12; pelvic-fin rays i,6.Dorsal-fin margin straight; dorsal-fin base situated on posterior onehalf of the body; base of last dorsal-fin ray located at vertical through base of third or fourth anal-fin ray; first branched ray longest with following rays gradually decreasing in length.Pectoral fin pointed, tip reaching vertical through distal onethird of pelvic fin.Anal fin margin straight, first branched anal-fin ray longest; following rays gently decreasing in length.Margin of caudal fin truncate; median rays extend to varying degrees beyond margin of remainder of fin.Scales present over basal one-third of fin.
Scales cycloid, thin, large.Lateral line distinctly decurved ventrally, completely pored from supracleithrum to base of caudal-fin rays.Forty-three to 47 (mean = 45.1, n = 12) scales in lateral line; 7 scale series between lateral line and dorsal-fin origin; 2 scale series between lateral line and pelvic-fin insertion.One large scale between pectoral-fin insertion and midventral keel; 18-22 scales along mid-dorsal line between tip of supraoccipital process and dorsal-fin origin.Four rows of scales on caudal peduncle.Dorsal-fin rays ii,9; anal-fin rays iii,28-32 [32] (mean = 29, n = 13); pectoral-fin rays i,11-13 [12]; pelvic-fin rays i,6.Dorsal-fin base situated on posterior one-half of the body; base of last dorsal-fin ray located along vertical through first anal-fin ray.Pectoral fin long, reaching posteriorly to vertical through tip of pelvic fin.First branched anal-fin ray longest; following rays rapidly decreasing in length.Caudal fin emarginate, covered by scales only basally.Middle caudal-fin rays terminate at posterior margin of remainder of fin.Total vertebrae 40 [40].

Fig. 23 .
Fig. 23.Map of central and northern South America showing geographic distribution of Triportheus magdalenae (circles; asterisk = type locality), T. pantanensis (black squares; white square = type locality) and T. orinocensis n. sp.(triangles; white diamond = type locality) (some symbols represent more than one locality or lot of specimens).
Triportheus venezuelensis is distinguished among deep bodied congeners by the combination of the number of gill rakers on the lower limb of the first gill arch (27-33, mean = 30.1,n = 55); the number of branched anal-fin rays (24-27, mean = 25.6, n = 54); and the number of lateral-line scales (33.0-36.0,mean = 34.0n = 51).Description.Morphometric data for Triportheus venezuelensis presented in Table 18.Body deep and compressed laterally.Greatest body depth located slightly posterior to vertical through pectoral-fin insertion.Dorsal profile of head straight from upper lip to rear of head.Dorsal profile of body gently curved from rear of head to dorsal-fin origin; Morphometrics of Triportheus venezuelensis.Ranges include measurements of 55 paratypes: USNM 258079 (6), USNM 233784 (12), USNM 270343 (17), UNELLEZ 52000 (3), FMNH 85488 (10), INHS 34573 (3), INHS 35077 (4).posteroventrally slanted from dorsal-fin origin to caudal peduncle; curved along caudal peduncle.Dorsal portion of body slightly keeled.Ventral profile of head straight from tip of lower lip to anteroventral margin of dentary.Ventral profile of head and body arched from base of dentary to pelvic-fin insertion; slightly curved or almost straight from pelvic-fin insertion to anal-fin origin; posterodorsally slanted along anal-fin base; straight along caudal peduncle.Prepelvic region expanded ventrally and strongly keeled.Head blunt in profile; posterior margin of opercle almost reaching vertical through pectoral-fin insertion.Snout vertically straight.Mouth terminal; upward.Lower jaw as long as upper jaw.Nostrils of each side close together; anterior opening circular; posterior elongate.Gill rakers thick and separated; length equivalent to one-half of length of branchial filament; gill rak-ers on lower limb of first arch 27-33 [32] (mean = 30.1,n = 55).
cites the material that served as the basis of the description of Chalcinus angulatus signatus as having been collected by the Thayer expedition and deposited in MCZ, but did not provide catalog numbers for the type-material.MCZ 21267 consists of 17 specimens labeled as syntypes of Chalcinus angulatus signatus.