Parambassis serrata

description

Description. Morphometric data and counts are presented in Table 1. Body laterally compressed. Dorsal profile slightly arched from tip of snout to occiput, rising steeply up to first dorsal-fin origin, sloping ventrad towards caudal-fin base. Ventral profile convex up to posterior end of anal-fin base, then sloping dorsad towards caudal-fin base. Eye large, its margin free. Gill membranes free from isthmus; 6 branchiostegal rays. First branchial arch with 17 − 18 gill rakers. Nasal spine present. Preorbital ridge with 3 − 4 (12) retrose spine-like serrae, partly hidden beneath skin; preorbital edge with 4 − 8 (12) distinct, exposed serrae projecting ventrally; suborbital ridge not serrated. Supraorbital ridge with 3 − 6 (12) retrorse serrae, partly subdermal; preopercular ridge with 4 – 9 (12) large serrae. Lower edge of preoperculum with 7 – 14 (12) serrae, posteriormost ones largest; hind margin of preopercular with 10 – 18 (12) minute denticulations. Interoperculum smooth or with 2 − 7 weakly developed serrae (Fig. 3). Body covered by scales, except in predorsal region. Head naked, except 3 − 4 (12) scale rows on cheek. Lateralline scales 49 − 53 + 2 − 3 (12); 6 (12) rows of sca

Parambassis serrata, a new species of glassperch (Teleostei: Ambassidae) from the Kaladan drainage, India

diagnosis

Diagnosis. Parambassis serrata is distinguished from its closest congeners by the combination of the following characters: a faint vertically-elongated brown humeral blotch; posterior margin of most spines of first dorsal fin proximally black in colour; absence of predorsal scales; 51 − 56 scales in lateral series; 14 − 16 dorsal- and anal-fin branched rays; a black longitudinal stripe on ventral surface of caudal peduncle; 17 − 18 gill rakers on first gill arch; 4 − 9 large serrae on preopercular ridge; and 11 pectoral-fin rays.

Parambassis serrata, a new species of glassperch (Teleostei: Ambassidae) from the Kaladan drainage, India

distribution

Distribution. Parambassis serrata is known only from the type locality, the Kolo River, Kawlchaw, Lawngtlai District, Mizoram, India (Fig. 4).

Parambassis serrata, a new species of glassperch (Teleostei: Ambassidae) from the Kaladan drainage, India

etymology

Etymology. The species name alludes to the serrated preopercular ridge. An adjective. Habitat. The type locality, Kolo River (Fig. 5) has clear, shallow water with a depth of about 0.05 m to 1.0 m (during the month of April-May). It flows from southeast to northwest and the water is fast-running, with numerous riffles among the boulders and smaller rocks. The Kolo drains into the Kaladan River. Other species occurring with Parambassis serrata include: Barilius profundus Dishma & Vishwanath, Devario sp., Garra sp., Gyptothorax ater Anganthoibi & Vishwanath, G. churamanii Rameshori & Vishwanath, G. jayarami Rameshori & Vishwanath, Olyra sp., Pethia expletiforis Dishma & Vishwanath and Semiplotus modestus (Day).

Parambassis serrata, a new species of glassperch (Teleostei: Ambassidae) from the Kaladan drainage, India