Diagnosis: gill slits not extending ventrally beyond pectoral-fin insertions; snout rounded, at most 65% of head length; post-orbital length at most 60% of snout length; maxillary barbels not fringed or very slightly fringed at base, shorter than head, unbranched and without tubercles or membranes (although a tiny rudiment may occasionally be discernible at their bases); outer mandibular barbels with few simple and rather long ramifications; branches of inner mandibular barbels short, subdivided and more or less tuberculate; mandibular teeth numbering 31-47 (40 in the neotype); dorsal-fin spine short and smooth anteriorly; denticulation of pectoral-fin spines finer on outer than on inner margin; humeral process narrow, triangular, rather pointed and not keeled ventrally; adipose fin rather long and distinctly separated from rayed dorsal fin, its height variable with specimens; head very broad, snout rounded and eyes small, in dorsal position (Ref. 57223).

Coloration: preserved specimens dark brown; according to Daget (1954), colour in life «olivaceous yellow on back and sides, lighter on belly»; body and adipose fin covered with large black spots, which become smaller on belly and on other fins (Ref. 57223).