Triportheus venezuelensis, Malabarba, 2004

Malabarba, Maria Claudia S. L., 2004, Revision of the Neotropical genus Triportheus Cope, 1872 (Characiformes: Characidae), Neotropical Ichthyology 2 (4), pp. 167-204 : 200-202

Triportheus venezuelensis , new species Fig. 26

Holotype. INHS 34768, 118.64 mm SL, Venezuela, Barinas, río Masparro , Apure drainage, 5 km NW Libertad on road to Barinas, 25 Jan 1995, L. M. Page, J. W. Armbruster, P. A. Ceas, K. S. Cummings & C. A. Mayer (08°20”N, 69°39”W).

Paratypes. Venezuela: Bolivar: USNM 270343(17,65.7- 83.4 mm SL), UNELLEZ 52000 (3,73- 83.4 mm SL), small caño connecting with rio Orinoco immediately South of El Burro , 9 Dec 1984, R. Vari,O. Castillo & C.Ferraris (06°11’N, 67’25’W); INHS 35077 (4, 80.6-83.1 mm SL), laguna Castillero , 10 Jan 1988, M. Rodriguez (07°38’N, 66°09’W) . Apure: USNM 258079 (6,76-85 mmSL), río Apure, W of town center, 25 Jan 1983, O. Costillo et al. (7º53’N; 67º29’W) ; FMNH 85488 (10, 36.3-73.6 mm SL), river 24 km S of Biruaca on road to San Juan de Apayara , 7 Jan 1975, J. Thomerson & D.Taphorn (07°56’S, 67°5’W) . Monagas: USNM 233784 (12, 75.6-94.6mmSL); USNM 358223(5,73.5-87.7mmSL); MCP 35842 (1, 82.4 mm SL), río Orinoco, laguna Tapatapa on Isla Tapatapa near downstream end of caño Limon , 16 Feb 1978, J. Lundberg & Lopez (8º32’N, 62º26’W). Guarico: INHS 34573 (3, 68.1-69.8 mm SL), laguna Caricare , 14 Jan 1995, J. Armbruster, P. Ceas, M. Campos, R. Suarez & J. Llerandi (7º50’N, 66º32’W) ; INHS 34484 (2, 82.4-83.1 mm SL), río San Bortolo at Águas Muertas , 8 Jan 1995, L. M.Page et al. (08º04’ N, 40º50’ W) ; INHS 35294 (3, 74.3- 77.9 mm SL), río Orinoco, laguna Larga Ii , 12 Jan 1987, M. A. Rodríguez & S. Richardson (07º38’N, 66º13”W); INHS 35114 (8, 63.1-77.3 mm SL), río Aguaro, P. N. Aguaro-Guariquito en El Paso , L. M. Page et al., 11 Jan 1995 (07º50’N, 66º30’W) .

Diagnosis. A deep-bodied Triportheus species reaching 94.9 mm SL (depth at dorsal-fin origin,26.7-37.6, mean = 32.9% SL, n = 54; depth at pectoral-fin insertion, 29.2-38.4,mean = 36.1% SL, n = 55). 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. 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 thenumberoflateral-linescales(33.0-36.0, mean = 34.0 n = 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;

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.

Scales cycloid, thin, and large. Lateral line distinctly de-

curved 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 in-

sertion and midventral keel; 4-5 scale series on caudal peposteroventrally slanted from dorsal-fin PROOFS origin to caudal pe- n with origin duncle = Dorsal-fin 54 6. -). 12; Scales pectoral-fin scales rays along from ii,9 mid-dorsal rays; tip anal-fin of i,10 supraoccipital -12 rays line [10 iii very,] 24 (mean -27 irregularly spine [25 =] 11.6 (mean to dorsal-fin, arranged n = = 25.6 50);, duncle; curved along caudal peduncle. Dorsal portion of body

pelvic-fin rays i,6. Base of dorsal-fin situated on posterior oneslightly keeled. Ventral profile of head straight from tip of lower lip to half of body; base of last dorsal-fin ray located anterior to anteroventral margin of dentary. Ventral profile of head and vertical through anal-fin origin; second unbranched and first body arched from base of dentary to pelvic-fin insertion; branched ray longest with following rays gradually decreasing slightly curved or almost straight from pelvic-fin insertion to in length. Pectoral fin pointed with tip extending posteriorly as anal-fin origin; posterodorsally slanted along anal-fin base; far as vertical through middle of pelvic fin. Anal-fin margin straight along caudal peduncle. Prepelvic region expanded slightly curved, first branched anal-fin ray longest with followventrally and strongly keeled. ing rays gradually decreasing in length. One or 2 series of scale Head blunt in profile; posterior margin of opercle almost overlaying basal portions of anal-fin rays. Margin of caudal fin reaching vertical through pectoral-fin insertion. Snout verti- truncate with median rays extending for one-half of their length cally straight. Mouth terminal; upward. Lower jaw as long as beyond margin of remainder of fin. upper jaw. Nostrils of each side close together; anterior open- Total vertebrae 38. ing circular; posterior elongate. Gill rakers thick and separated; length equivalent Coloration in alcohol. Overall ground color yellowish brown. to one-half of length of branchial filament; gill rak- Snout and dorsal portion of head dark. Some scattered dark

chromatophores present on opercle and postorbital region. Concentration of chromatophores forming diffuse stripe extending from supracleithrum to caudal peduncle; stripe broadened into wider dark spot on lateral surface of caudal peduncle. Body darker dorsal to midlateral stripe. Dorsal-fin rays outlined by dark chromatophores. Scattered dark chromatophores distributed all over pectoral fin; with more intense dark pigmentation on first unbranched ray and along fin margin. Some dark chromatophores outlining anal-fin rays. Median caudal-fin rays 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

Figures

Fig. 26. Triportheus venezuelensis, holotype, INHS 34768, 118.64 mm SL, Venezuela, Barinas, río Masparro, ríoApure drainage, 5 km NW of Libertad on road to Barinas.

Fig. 12. Map of central and northern South America showing geographic distribution of T. culter (circles; asterisk = type-locality), T. albus (squares; asterisk = type-locality), T. nematurus (triangles; diamond = type-locality) and T. venezuelensis (lozenges; white square = type-locality) (some symbols represent more than one locality or lot of specimens).