Abstract: A cave-dwelling loach,Oreonectes guananensis sp.nov.was recognized based on collections from several caves in Guan'an village,Changmei town,Huanjiang County,Guangxi,China,in June 2010.It can be distinguished from all known Oreonectes species by the following combination of characters:7 branched dorsal-fin rays,5 branched anal-fin rays,10～11 branched pectoral-fin rays,7～8 branched pelvic-fin rays and 13～17 branched caudal-fin rays;head compressed;eyes present;surface of lower lip covered with shallow longitudinal groove;dorsal-fin origin opposite or posterior to vertical line of pelvic-fin origin;caudal peduncle without caudal-adipose keels;edge of caudal fin rounded;scales present;cephalic lateral-line system developed;lateral line incomplete,with 7～13 pores;a dark brown stripe present along lateral line;posteriorchamber of air-bladder developed,extending to nearly pelvic-fin origin.

Key words: Balitoridae, Oreonectes, new species, Guangxi,China