Laubuka latens

description

Description. See Table 1 for morphometric and meristic characters, and Figures 1 A and 2 for general appearance. Body slender, its depth about one-fourth standard length, laterally compressed, its dorsal profile slightly curved, ventral profile deeply convex, keeled from origin of pelvic fin to anus. Dorsal fin with 2 simple and 7 ½ branched rays, its posterior margin slightly concave, its origin above branched anal-fin ray 4 (6) or 5 (2). Pelvic fin falcate, with 1 unbranched and 5 branched rays, the unbranched ray being filamentous, reaching beyond anus, sometimes to base of second anal-fin branched ray. Anal fin with 3 simple and 18 ½ (2), 19 ½ (4) or 20 ½ (2) branched rays, its ventral margin deeply concave, with a sharp curve among the first few branched rays. Pectoral fin with 1 simple and 11 (2) or 12 (6) branched rays. Caudal fin deeply forked, its lobes subequal, with 1 + 9 + 8 + 1 rays. Head small, its dorsal profile almost straight, a slight indentation at nape. Eyes large, placed forward, their diameter greater than snout length. Mouth oblique, angle of gape slightly below level of lower margin of eye. Lower jaw devoid of tubercles, with 5 pores medially on dentary. Nos

Description of two new species of Laubuka (Teleostei: Cyprinidae) from River Cauvery, southern Iandia

diagnosis

Diagnosis. From amongst its Indian congeners, Laubuka latens is distinguished from L. laubuca by possessing 7 ½ branched dorsal-fin rays (vs. 8 ½); a lesser prepelvic length (41.1 – 42.9 % SL, vs. 44.8 – 48.8 % SL); a longer (14.9 – 16.5 % SL, vs. 11.9 – 13.1 % SL) and slenderer caudal peduncle (7.8 – 8.8 % SL, vs. 9.3 – 10.6 % SL); lesser body depth (22.9 – 25.9 % SL, vs. 27.4 – 32.6 % SL); shorter dorsal-fin base (10.4 – 12.1 % SL, vs. 13.2 – 16.9 % SL) and a greater pelvic-fin length (23.2 – 26.9 % SL, vs. 15.9 – 20.5 % SL). Moreover, L. latens when compared to L. laubuca, has the posterolateral surface of the supraorbital with a shallow concavity (vs. convex) (Fig. 3 - 8, 22); anterior margin of third suborbital slightly concave (vs. straight) (Fig. 3 - 9, 23); anterior end of maxilla rounded (vs. notched) (Fig. 3 - 10, 24); dentary with the coronoid process blunt (vs. posteriorly pointed), its inferior border slightly convex (vs. straight) (Fig. 3 - 11, 25); posterior margin of fifth ceratobranchial smooth (vs. with a sharp process) (Fig. 3 - 12, 26); postero-dorsal margin of opercle deeply concave (vs. straight) (Fig. 3 - 13, 27); caudal skeleton with a broad (vs. slender) ep

Description of two new species of Laubuka (Teleostei: Cyprinidae) from River Cauvery, southern Iandia

distribution

Distribution. Laubuka latens is at present known from the Cauvery River system at Gandehosahalli in Karnataka and Hogenakkal in Tamil Nadu, India, but probably occurs throughout a wider range in the Cauvery River and its tributaries.

Description of two new species of Laubuka (Teleostei: Cyprinidae) from River Cauvery, southern Iandia

etymology

Etymology. The species name is derived from Latin, latens = hidden, an allusion to the identity of the species being hidden, as it was overlooked in earlier ichthyofaunal surveys owing to it having been confused with Laubuka laubuca. The species name is a noun in apposition.

Description of two new species of Laubuka (Teleostei: Cyprinidae) from River Cauvery, southern Iandia