A new species of spined loach from the southern Shikoku Island, Japan (Cypriniformes: Cobitidae).

Cobitis tosaensis, a new species of spined loach, is described from southern Shikoku Island, Japan. It is distinguished from its nearest congener, C. biwae, by the following combination of characters: Suborbital spine with three pointed ends, lamina circularis kitchen-knife shaped, Z2 almost thick as eye diameter in many individuals, two black spots on surface layer of caudal-fin base-both usually separated from upper and lower, two light greyish spots on deeper layer of caudal-fin base-both separated from upper and lower.