Diagnosis: head broad (width at least 2/3 of length); snout length less than 0.9 times head width; hind margin of adipose fin nearly straight; premaxillary dentition forming (in adults) 2 well separated, kidney-shaped plates; maxillary barbels never black and reaching at least to hind margin of eye; 8-11 (usually 9 or 10) gill rakers on lower limb of first gill arch; palatine membrane bilobed (with a large and a smaller lobe); dorsal margin of cleithral process broad and flat (visible only in adults)(Ref. 57126).
Description: body rather deep (about 4-5 times in standard length); occipital process broad (ratio width/length from 0.9 (juveniles) to 1.3 (adults), rather rounded and contiguous to the concave-edged first nuchal plate; dorsal fin with 2 spines, the first small, the second strong and denticulate; adipose fin high, increasing steeply backwards, its posterior margin rather straight; palatine membrane with a well developed lobe, and sometimes, a smaller lateral lobe; dorsal process of cleithrum flat and broad (visible only in adults); premaxillary dentition forming a small band (twice as long as broad) in juveniles, developing with growth into 2 small, well separated tooth plates, the entire band being 1.4-1.8 times as long as broad; head broad (width 65-75% of length), snout short (50-68% of head length), showing no great differences between juveniles and adults; nasal barbels absent; pelvic fin with 1 unbranched and 5 branched soft rays (Ref. 57126).
Coloration: body in juveniles marbled, with 7 or 9 series of black dots, in adults uniformly brownish; fins also marbled in juveniles, uniform brownish, in adults sometimes with some small, very distinct, black spots (Ref. 57126).