Diagnosis: caudal peduncle relatively long, its depth a little larger than horizontal distance between the base of adipose and caudal fins (but almost never twice as great); pectoral spine smooth on its anterior margin, except for a few serrations near the tip; preorbital head length less than maximum head depth; color pattern on flank strongly marked in most cases; adipose fin height 3-7% SL, dorsal fin height 15-25% (28%) SL), head depth 56-88% head width; barbels relatively short, e.g. external mandibular barbel usually shorter than 1.3 times HL, never reaching beyond tip of pectoral spine (Ref. 81642).

Description: body moderately elevated, head depth generally greater than (rarely equal to) preorbital length; maxillary barbel just reaching base of pectoral spine (Ref. 81642).

Coloration: preserved specimens brown or grey; head often somewhat darker; flanks with large spots (usually as large as or larger than eyes), which may merge together; number, position and intensity of these spots highly variable, and often vertical or horizontal series are present; markings most intense anteriorly where spots often merge into a single large irregular blotch; head and fins may or may not be spotted; ventrum creamy white (Ref. 81642).