Sebastes inermis, the Japanese red seaperch or dark-banded rockfish, is a species of marine ray-finned fish belonging to the subfamily Sebastinae, the rockfishes, part of the family Scorpaenidae. It is found in the northwestern Pacific Ocean. This species is known as mebaru in Japan and as bollak in Korea. Sebastes inermis has sharp lachrymal spines with the rest of the spines on the head are rather weak. The caudal fin is not strongly emarginate. It has a dark red or pale brown body on the back and flanks. The pectoral fins reach beyond the level of the anus when held down., The pectoral fins have 15 rays while the anal fin has 7 rays. This species grows to a total length of 36 cm (14 in), and the heaviest recorded specimen weighed 800 g (1.8 lb). Sebastes inermis it occurs from southern Hokkaido southward to Kyushu, Japan, and the southern part of the Korean Peninsula. It is a demersal fish with pelagic juveniles which live among floating mats of seaweeds.
