This species is diagnosed from its congeners, except Olyra horae, by having following characters: adipose fin confluent with caudal base; pectoral fins with weak serrations and strong dentitions internally consisitng of 10-12; anal fin with 15 rays; length of the adipose fin base 31.2-33.2% SL; distance of dorsal fin origin to origin of adipose fin 21.6-22.5% SL; and 17-23 pores of the lateral line canal. It differs from O. horae by having 15 anal fin rays (vs. 21) upper lobe of caudal fin extending posteriorly by a length that is more than half the length of the lower lobe (vs. slightly longer than lower). The following combination of characters separate this species from other congeners: pre-dorsal length 41.9-42.3 % SL; pre-anal length 61.8-66.2 % SL; anal fin base length 23.6-25 % SL; length of the lower lobe of the caudal fin 21.4-21.6 % SL; caudal peduncle length 10-10.6 % SL; caudal peduncle depth 11.1-11.4 % SL; head length 23-23.6 % SL; nasal barbel length 42-42.2% HL; head width at eye 50.5-51.3% HL; eye diameter 12.2-12.9% HL; dorsal fin rays i 6; pectoral fin rays i 6; caudal fin rays 27 rays; pelvic fin length 15-15.1 % SL; pectoral fin length 11.3-12.1% SL; body depth 9.1-9.9% SL; and
snout length 32.1-33% SL (Ref. 93959). |