Holotype: MB-HNUE VI.l-FOI
female, 51.4 mm SL
Vietnam: Quang Ninh Prov., Tien Yen River at Binh Lieu town
Nguyen Huu Duc et aI., 14 March 2011. Paratype: I MB-HNUE VI.I-F02, male, 60.5 mm SL. Same data as holotype. Diagnosis: When Acheilognathus nguyenvanhaoi sp. n. is compared with closely related species of Acheilognathus, it is characteristic in the five following traits: a broad and dark longitudinal stripe on body (both sides) running from tip of snout to tip of middle caudal fin rays, not tapering anteriorly vs. a narrower and lighter one running most anteriorly behind operculum to caudal base, tapering anteriorly
pharyngeal teeth (5.1-0.5, vs. 5-5)
spiny rays of dorsal and anal fins (III-IV, vs. III) and scales above lateral line (7, vs less than 6). The new species differed from A. meridian us and A. barbatus in number of predorsal scales
from A. meridianus, A. barbatulus and A. melanogaster in number of vertebrae
from A. melanogaster in lenght of barbel
from A. brevicaudatus and A. melanogaster in number of gill rackers on the outer side' of the first gill arch and from A. barbatulus and A. melanogaster in proportion between anterior and posterior length of gas-bladder.