A nemacheiline loach
Yunnanilus longibarbatus
sp. nov. (Holotype: KIZ 2003050255, 52.6 mm SL) has been recognized based on collections from a Hongshui River Drainage in Gaoling Township, Du-An county, Guangxi, China, in May 2003.
Yunnanilus longibarbatus is a new member of the
Yunnanilus nigromaculatus group and is closely related to Y. nigromaculatus (Regan),
Y. obtusirostris Yang,
Y. longidorsalis Li et al and
Y. bajingensis Li.
Yunnanilus longidorsalis can be distinguished from the other species using the following characters: branched dorsal fin rays 11 vs. 8-9; maxillary barbel only reaching mid-eye vs. posterior edge of eye; and dorsal-fin origin closer to snout tip than caudal fin base vs. vice versa.
Yunnanilus longibarbatus and
Y. obtusirostris have neither a processus dentiformis on the upper jaw nor a median notch on the lower jaw, making them different from Y. nigromaculatus and
Y. bajingensis.
Yunnanilus longibarbatus is most closely related to
Y. obtusirostris through sharing many features, such as: fin-ray count; jaw structure; position of dorsal-fin; shape of caudal-fin; coverage of scales; absence of cephalic lateral line system; and presence of a lateral stripe on the body.
Yunnanilus longibarbatus can be distinguished from
Y. obtusirostris using the following characters: maxillary barbel reaching to the posterior edge of the opercle, making it the longest barbel in the genus
Yunnanilus; presence of a non-prominent dark spot on the lower 1/3 unbranched dorsal-fin rays; lateral stripe width smaller than eye diameter vs. almost equal; lateral stripe on anterior body dissolved into blotches in large-sized specimens vs. not dissolved; has dots on dorsal head vs. absent; caudal-peduncle slender, with length 5.3-6.1 times the standardlength vs. 7.4-9.0 and length 1.3-1.8 times its depth vs. 0.8-1.1.
