BéarlaDiagnosis: head relatively broad, 14.2-20.9% of standard length (Ref. 57129). Wide interorbital distance (Ref. 248), 41.3-51.8% averaging 46.4% of head length (Ref. 57129). Large tooth plates (Ref. 248), width of premaxillary tooth plate 25.9-37.2% of head length (m=29.5), width of vomerine tooth plate 21.0-31.2% of head length(Ref. 57129). Barbels extremely long (Ref. 248, 57129), nasal barbel 77.8-187.5%, maxillary barbel 142.9-305.8%, inner mandibular barbell 58.9-128.7%, and outer mandibular barbell 104.3-211.2% of head length (Ref. 57129). Head rather rectangular in dorsal outline; eyes more laterally located (Ref. 248). Frontal fontanelle long and narrow ("knife-shaped")(Ref. 248, 57129). Occipital fontanelle oval-shaped; pectoral spine robust and slightly curved; gill rakers on first branchial arch long and slender; suprabranchial organ well developed, however not completely filling the cavity; openings of secondary canals of lateral line irregularly placed on the body (Ref. 248).
Coloration: both live and preserved specimens usually dark-coloured; 2 types of colouration, one uniform dark brown to black on back and sides and light on belly, the other marbled, with small brown spots against a light background on back and sides and belly whitish; marbled specimens have very dark unpaired fins; caudal fin with a series of vertical bars (a light bar in the middle flanked by dark ones)(Ref. 57129).