Moderate mouth with a nearly transverse or slightly arched opening with the extremities slightly curved posteriorly and its width equal to or slightly less than the corresponding head width and a short post-labial groove extending along half of the length of the lower jaw lateral margin. Differs from all other species of Onychostoma, except Onychostoma meridionale and Onychostoma fusiforme, with a moderate mouth by the possession of a longitudinal dark brown stripe extending along the lateral line. Can be diagnosed from these two species in having two pairs of barbels in adults (vs. present in juveniles, but absent in adults in Onychostoma fusiforme, or absent in adults and juveniles in Onychostoma meridionale. Differs further from Onychostoma fusiforme by having the following characters: deeper body depth 26.3-27.7% SL (vs. 20.4-23.8), stouter caudal peduncle (length 18.5-21.0% SL, vs. 20.5-23.7 and depth 7.6-9.1% SL vs. 6.7-8.0 or depth 36.1-48.8% of its length vs. 29.7-37.5); prepelvic length 49.8-51.3% SL (vs. 46.2-48.7); preanal length 72.6-74.8% SL (vs. 68.3-71.5). Also distinguished from Onychostoma meridionale in having a stout, serrated last simple dorsal-fin ray (vs. slender, smooth) (Ref. 82789).

Description: dorsal fin with 4 simple and 9 branched rays; anal fin with 3 simple and 6 branched rays; pectoral fin with 1 simple and 15 or 16 branched rays; pelvic fin with 1 simple and 9 branched rays (Ref. 82789).