Palate without teeth (but autogenous tooth plates present); jaw teeth slender, in short, oblong band. Lips fleshy, thin; mouth small, lower jaw truncate. Barbels thin, short, maxillary barbel reaching only just beyond eye; base of chin barbels close together. Eye large, 14-24% HL, lateral. Dorsomedian head groove elongate, deep posteriorly. Gill rakers along posterior of all arches; gill opening slightly restricted; two large epithelial flaps on palate posteriorly and double folds on upper limb of first two gill arches. Longitudinal furrows anterodorsally on body. Fin spines thin, long, slender; adipose fin short-based, over posterior two-thirds of anal; ventral fin pad of sexually mature females scalloped and tapered. Dark grey above and iridescent purple; palate and branchial chamber often purplish brown to charcoal (Ref. 40908).