This species is distinguished by the following characters: elongated body is nearly rectangular in cross-section, almost flat ventrally, its depth 6.2 to 7.9 times in standard length (SL); 45-47 vertebrae; 25-30 predorsal scales; scales in transverse row 6 to 7.5, usually 6.5; the head 4.2-5.2 times in SL: eye 3.1-3.3 times in head; subequal jaws; jaw teeth conspicuous, conical; no palatine teeth; gill rakers on first arch 25-31; dorsal fin low, with 10-12 rays; anal fin with 10-13 rays, originating slightly before, or 1-2 rays behind dorsal-fin origin; pectoral fins 1.3-1.4 times in SL and with 16-18 rays, first 2 rays unbranched; pelvic fins 2.8-3.4 times in SL, inserted slightly nearer to posterior margin of opercle than origin of caudal fin base: juveniles without barbel (Ref. 109257). Colour of body dark, iridescent blue above, silvery white below; dorsal and caudal fins greyish, other fins hyaline (Ref. 2797); pectoral fins black without unpigmented cross-band and with a narrow light outer margin; pelvic fins usually without black spot (Ref. 109257); juveniles elongate, paired fins black (Ref. 2797).