Diagnosis: body relatively elongate; abdomen not greatly expanded, more or less extensively darkly pigmented; sucker very large, longer than broad (not transversely oval), extensively covered with moderately large papillae; mandibular barbels short but well-developed, usually papillose, with up to 3 auxiliary mandibular barbels on each side of lower lip; large premaxillary teeth in 3-4 rows; mandibular teeth large, usually 4+4 or 5+5 (but some with 7+7 or 8+8); eyes large; adipose fin long, its origin considerably in advance of a vertical through anal fin origin; caudal peduncle moderately slender to very slender; caudal fin not deeply forked with lobes rounded or even truncate, lower slightly longer than upper (Ref. 81251).

Coloration: body with dark bands fairly distinct; abdomen more or less darkly pigmented, almost black in some specimens (Ref. 81251).