Diagnosis: gill slits extending downwards beyond pectoral-fin insertions, but remaining separate by an interval greater than eye diameter; maxillary barbels not longer than head, without tubercles or ramifications, but with a broad black membrane almost extending over their entire length; mandibular barbels without membrane; ramifications of outer mandibular barbels few and simple, those of inner mandibular barbels more numerous and subdivided; mandibular teeth slender and short, numbering 30-57; pectoral-fin spines more strongly denticulate on inner than on outer margin; anterior margin of dorsal-fin spine smooth, except for some apical serrations; humeral process rather deep, granulose and weakly keeled ventrally; adipose fin high and almost contiguous to rayed dorsal fin (proportionately

less high in young individuals)(Ref. 57223).

Coloration: typically an inverted colour pattern, the back being light grey and the belly black; pelvics, anal and caudal fins always covered with transversely aligned spots; other spots also tend to form transverse series, but these are not as well-defined; maxillary barbels bordered by a broad, black membrane (Ref. 57223).