Cirrhimuraenataiwanensis sp. nov., a new species of cirri-bearing eel (Anguilliformes, Ophichthidae) from Yilan, northeastern Taiwan.

A new species of cirri-bearing eel, Cirrhimuraenataiwanensis sp. nov. (Anguilliformes, Ophichthidae), is described based on a specimen collected from the estuary of the Langyang River (Yilan County), northeastern Taiwan. The new species is distinct from all congeners, except C.odishaensis and C.orientalis, in possessing a single row of mandibular teeth. Cirrhimuraenataiwanensis sp. nov. differs from C.odishaensis in having significantly shorter pectoral fins and fewer vertebrae, and it is distinguished from C.orientalis by its larger head, notably more total vertebrae, and a dorsal fin that originates well behind the gill opening. In the neighbor-joining tree based on COI sequences, the new species forms a distinct monophyletic group; thus, it is clearly separable from congeners both morphologically and genetically. With this addition, there are now 13 species in the genus Cirrhimuraena.