This species is distinguished by the following characters: elongated body nearly rectangular in cross-section, almost flat ventrally, its depth 5.5-7.1 times in standard length (SL): vertebrae 44-47; predorsal scales 26-32; scales in transverse row 5.5-7.5, usually 6-6.5; head 4.5-5.1 times in SL: eye 2.8-3.0 times in head; subequal jaws conspicuous and conical teeth; no palatine teeth; gill rakers on first arch 25-32; low dorsal fin 10-13 rays; anal fin with 11-13 rays, originating slightly before, or 1-2 rays behind dorsal-fin origin; pectoral fins 1.2-1.4 times in SL, with 17-20 rays, first 2 rays unbranched; pelvic fins 2.7-3.5 in SL, inserted slightly nearer to posterior margin of opercle than origin of caudal-fin base; juveniles not barbelled; colour of body dark above and pale below, dorsal and caudal fins greyish, anal fin transparent, pectoral fins black without unpigmented cross-band and with a moderate light outer margin, pelvic fins without black spot; juveniles that are less than 10 cm are without vertical bands on body and with the dorsal, pectoral and pelvic fins not mottled with dark spots and bands (Ref. 109257).