In the present study, a new species of the genus
Sinocyclocheilus
Fang 1936,
Sinocyclocheilus xichouensis
, was described from the Ganhaizi tributary of Chouyang River, Red River drainage, located in southeast Yunnan, China. This species has normal eyes and a strong dorsal spine with serrations on the lower 3/5 part. In general, this species is similar in morphology to
S. macrophthalmus
,
S. guishanensis
,
S. angustiporus
,
S. lateristritus
,
S. qiubeiensis
,
S. grahami
,
S. qujingensis
,
S. maculatus
and
S. purpureus
distributed in the Nanpanjiang River, and S. qiubeiensis distributed in the Red River. It is distinguished from
S. macrophthalmus by possessing fewer than 9 gill rakers. However,
S. xichouensis can be distinguished from
S. guishanensis by its interorbital width/SL of 8.1~9.9%, rostral barbels extended to posterior margin of eye and maxillary barbels extended to posterior preopercular. It is distinct from S. lateristritus by dorsal-fin origin opposite of pelvic fin origin, with no a black stripe along the lateral line. It is distinguished from
S. grahami by 74~88 lateral-line scales, 20 scale rows above the lateral line, and 16 scale rows below the lateral line. It is distinguished from S. qujingensis by a curved lateral line, 74-88 lateral-line scales, 48 circumpeduncular scales. It can be distinguished from S. yimenensis by the ratio of predorsal length, dorsal-fin base length, preanal length, anal fin length, prepectoral length, caudal-peduncle length and lower jaw length to SL, 47.1%-53.7%, 12.8%-15.8%, 66.0%-71.0%, 13.7%-17.1%, 26.0%-29.5%, 19.3%-24.7%, 4.7%-7.0%, respectively. It is distinguished from S. maculatus and S. purpureus by possession of lateral line and scaled body and distinguished from
S. angustiporus and
S. qiubeiensis by 35~39 predorsal scales, 6 gill rakers, and interorbital width/SL of 8.1%-9.9%.