Hypergastromyzon Roberts, 1989

Hui, Tan Heok, 2021, Hypergastromyzon revisited, with descriptions of a new genus and two new species (Teleostei: Gastromyzontidae), Raffles Bulletin of Zoology 69, pp. 336-363 : 337

Hypergastromyzon Roberts, 1989

Type species: Hypergastromyzon humilis Roberts, 1989 .

Diagnosis. Adapted from original diagnosis provided by Roberts (1989: 91).

A gastromyzontine loach with head and body wide and strongly depressed (body depth at dorsal-fin origin 9.4–15.9% SL, body depth 8.4–10.6% SL, caudal-peduncle depth 5.2–8.0% SL); pectoral and pelvic fins greatly enlarged (pectoral-fin rays 24–28, pelvic-fin rays 17–20); pectoral-fin origin below eye; pelvic fins completely fused posteriorly; mouth small, about a third of head width, with horny jaw sheaths strongly curved; three pairs of very short barbels, two rostral and one maxillary; rostral cap fused with upper lip except around base of rostral barbels; lower lip with medial groove well developed posterolaterally but interrupted anteromedially; snout rounded in dorsal view, strongly pointed in lateral view; gill opening lunate, length about equal to eye diameter, above middle of pectoral-fin base; subopercular groove absent; base of first pectoral-fin ray separated from head by a deep groove parallel to anterior edge of fin ray on ventral side of head and continuous dorsally on head to behind base of fin ray; dorsal surface of pectoral-fin base without scales; supra-pelvic flap originating immediately behind pectoral-fin base and continuing as a free flap above anterior third of pelvic-fin base; abdomen without scales; pored lateral scale rows 57–78; very short anal-fin base (2.3–5.3% SL); first anal-fin pterygiophore not bifurcated proximally; total vertebral count 30–32. Mature