Charax rupununi

description

Description. Table with complete morphometric data not presented since only the poorly preserved holotype and another more recently collected specimen of this rare species were available for study. Body elongate, small compared to congeners (38 - 45 mm SL), compressed and comparatively low. Greatest body depth slightly in advance of dorsal-fin origin. Dorsal profile of head and body slightly convex from tip of snout to anterior region of fontanel, slightly concave from that point to base of supraoccipital spine, slightly convex from that point to dorsal-fin origin, nearly straight along dorsalfin base and from end of dorsal-fin base to caudal peduncle and very slightly concave along caudal peduncle. Ventral profile of head and body convex from tip of lower jaw to analfin origin, nearly straight to slightly concave along anal-fin base and slightly concave from end of anal-fin base to beginning of procurrent rays. Snout pointed. Lower jaw included in upper jaw when mouth closed. Maxilla extending slightly beyond vertical through middle of orbit. Dorsal-fin rays ii, 9 (2) posteriormost ray unbranched. Adipose fin present. Unbranched anal-fin rays iv, branched rays 44 - 46. Pectoral-fi

A taxonomic review of the species of Charax Scopoli, 1777 (Teleostei: Characidae: Characinae) with description of a new species from the rio Negro bearing superficial neuromasts on body scales, Amazon basin, Brazil

description

Fig. 24 Charax rupununi Eigenmann, 1912: 402 (original description, type locality: Guyana, Rupununi River). - Henn, 1928: 70 (listed in type catalog). - Ibarra & Stewart, 1987: 22 (listed in type catalog). - Lucena, 1987: 50 (diagnosis, description; comparisons; distribution). - Lucena, 1989: 104 (in key to species). - Lucena & Menezes, 2003: 201 (maximum length; distribution). Charaxodon rupununi, Fernandez-Yepez, 1947 (in key to species).

A taxonomic review of the species of Charax Scopoli, 1777 (Teleostei: Characidae: Characinae) with description of a new species from the rio Negro bearing superficial neuromasts on body scales, Amazon basin, Brazil

diagnosis

Diagnosis. Charax rupununi is distinguished from congeners with the lateral line complete and the dorsal region of the body anterior to the dorsal fin scaled except for a small naked area anterior to the dorsal-fin origin in having 42 - 44 perforated scales along the lateral line (vs. 50 - 65 perforated scales on the lateral line in C. tectifer, C. metae, C. delimai, C. metae, C. caudimaculatus, C. notulatus, C. apurensis, C. macrolepis, C. michaeli, C. pauciradiatus, C. gibbosus, C. niger, and C. leticiae). Charax rupununi differs from C. hemigrammus, C. condei and C. stenopterus by having the lateral line complete and the dorsal region of the body anterior to the dorsal fin, except for a small naked area anterior to dorsal-fin origin scaled (vs. the lateral line incomplete and scales lacking on the dorsal region of the body anterior to the dorsal fin).

A taxonomic review of the species of Charax Scopoli, 1777 (Teleostei: Characidae: Characinae) with description of a new species from the rio Negro bearing superficial neuromasts on body scales, Amazon basin, Brazil

distribution

Distribution. The two known specimens of this species have been collected respectively in Rupununi, Guyana and Lago Jacaré, rio Trombetas, Brazil (Fig. 7). Specimens examined. FMNH 53663, holotype, 45 mm SL, Guyana: Rupununi, 4 ° 21 ’ 43 " N 59 ° 09 ’ 30 " W; MZUSP 27937, 1, 38 mm SL, Brazil, Pará, lago Jacaré, rio Trombetas, 1 ° 20 ’ S 56 ° 51 ’ W. Previously included in Lucena (1987).

A taxonomic review of the species of Charax Scopoli, 1777 (Teleostei: Characidae: Characinae) with description of a new species from the rio Negro bearing superficial neuromasts on body scales, Amazon basin, Brazil