Body cylindrical, greatest depth in front of dorsal-fin origin, sometimes with a conspicuous hump; head flat with pointed profile and depressed snout; nostril flap pointed, barbel-like, reaching anterior margin of eye; anterior nostril pierced on front side of flap; processus dentiformis present; mouth subterminal, lips smooth; no median notch in upper lip, lower lip interrupted medially; lateral line reaching at most level of anal-fin origin; anus at equal distance from pelvic-fin base and anal-fin origin; 8.5 branched dorsal-fin rays; 5.5 branched anal-fin rays; caudal fin emarginate, with 9+8 branched rays; axillary pelvic lobe present; 6-8 broad dark bars on body, quite regularly shaped, usually wider than interspaces; dorsal fin with two large black blotches along base; black bar at caudal-fin base not reaching lower and upper margin of caudal peduncle; body sometimes plain dark brown, independent of size (Ref. 36949).