New record of Japanese snake blenny Xiphasia matsubarai(Perciformes:Blenniidae) from South China Sea

Specimens belonging to the family Blenniidae were collected in a fishery resource investigation from the coastal waters of Xisha Islands and Hainan Island, South China Sea in 2016. Combining morphological results with sequence analysis, we identified one specimen as Xiphasia matsubarai Okada Suzuki, 1952. This represents a new record in the South China Sea. In morphology, the specimen has the following traits: body elongated, eel-like or ribbon-like in shape; flanks medium flat; the head small bluntly rounded anteriorly and without a moustache; eyes is slightly smaller, on upper lateral position of head, which is about equal to 1/5 of the length of the head; body without scales, lateral line has been degraded; both sides of the upper and lower jaws with a canine; gill is opening at the top of the pectoral fin base, approximately equal to the length of eye diameter. Dorsal fin Ⅺ, 96; pectoral fin 10; anal fin Ⅱ, 95. Head and body grey-brown, including 26 dark grey-brown bands; abdomen and lower operculum yellowish grey and colour lighter; and dorsal base long with dark grey. Origin of dorsal is located over the anterior margin of pupil; black blotch on dorsal fin between 8 th and 10 th dorsal spine; anal and caudal fins dark grey, pectoral and ventral fins pale yellow. Sequence analysis of cytochrome oxidase subunit I gene( COI) strongly supports the identity of the specimen as Ⅹ. matsubarai.