Pethia aurea, Marcus Knight, J. D., 2013

Marcus Knight, J. D., 2013, Pethia aurea (Teleostei: Cyprinidae), a new species of barb from West Bengal, India, with redescription of P. gelius and P. canius, Zootaxa 3700 (1), pp. 173-184 : 174-176

Pethia aurea , sp. nov.

( Figs. 1A , 2 )

Material examined. Holotype: ZSI / SRC, 8730, 23.6 mm SL, Ponds in South 24 – Parganas district, West Bengal, Andrew Rao, 10 Dec 2011. Paratypes: ZSI / SRC, 8731, 9, 20.2–22.5 mm SL, Ponds in South 24 – Parganas district, West Bengal, Andrew Rao, 10 Dec 2011.

Diagnosis. Pethia aurea is distinguished from all other species of Pethia by the combination of the following characters: lateral line incomplete, with 3–4 pored scales; 25–26+1 scales in the lateral series, ½5/1/3–3½ scales in transverse line on body; pre-dorsal scales 9; last unbranched dorsal-fin ray slender, serrated, with 19–22 serrae on posterior margin; barbels absent; a black band around the caudal peduncle covering scales 23–25 of the lateral series; a black blotch beneath the origin of the dorsal fin and a black spot above the origin of the anal fin.

Description. See Table 1 for morphometric data, and Figs. 1A and 2 for general appearance. Body deep, its depth greater than head length, laterally compressed, dorsal profile slightly curved, ventral profile deeply convex. Dorsal fin with 3 simple and 8½ branched rays, its height 84.2–108 % body depth. Last unbranched dorsal-fin ray straight, with 19–22 stout serrae on posterior margin. Pelvic fin rounded, with 1 unbranched and 8 branched rays. Anal fin with 3 simple and 5½ branched rays, its ventral margin slightly concave. Pectoral fin rounded with 1 simple and 14 (8) or 15 (2) branched rays. Caudal fin deeply forked, its lobes equal, with 9+8 principal rays.

Head small, about one fourth of standard length, its dorsal profile curved, a slight elevation at nape. Eye large, placed forward, its diameter about half of head length. Mouth subterminal, angle of gape reaching behind vertical beneath anterior margin of eye. Snout blunt, devoid of tubercles. Nostrils closer to eye than snout tip. Snout length less than eye diameter. Caudal peduncle slender, its length 1½ to 2 times its depth. Lateral line incomplete, with 3 (6) or 4 (4) pored scales on body, 25 (7), 26 (3) + 1 scales in lateral series. Predorsal scales 9; scales in transverse line on body ½5/1/3–3½. Circumpeduncular scales 9.

Coloration. In life (see Fig. 1A ), body golden yellow, abdomen white; a black band around caudal peduncle, covering scales 23–25 of lateral series. A black blotch beneath dorsal fin origin; a black spot above anal fin origin. Iris golden, dorsal fin black, faintly yellow at base; other fins hyaline. Specimens in preservative whitish with scattered melanophores along dorsum. Fins hyaline with melanophores scattered along base. All body pigmentation faded, black band around caudal peduncle reduced to a few closely-spaced melanophores ( Fig. 2 ).

Etymology. The species name is an adjective, ‘ aurea ’ = golden in Latin, a reference to the golden colour of this fish.

Distribution. Pethia aurea is at present known from ponds in South 24 Parganas District, West Bengal, India.

Figures

FIGURE 2. Pethia aurea, holotype, ZSI / SRC, F. 8730, 23.6 mm SL, pond in South 24 – Parganas District, West Bengal.

FIGURE 1. A, Pethia aurea, holotype, prior to fixation, ZSI / SRC, F. 8730, 23.6 mm SL, Ponds in South 24 – Parganas district, West Bengal; B, P. canius, neotype, prior to fixation, ZSI / SRC, F. 8732, 30.1 mm SL, Ponds in Cooch Behar district, West Bengal; C, P. gelius, neotype, prior to fixation, ZSI / SRC, F. 8735, 30.9 mm SL, river Torsa at Totapara in Jalpaiguri, West Bengal; D, P. gelius, ZSI / SRC, F. 8736, 29.8 mm SL, Chembarampakkam lake, Tamil Nadu.