Japanese red seaperch, Dark-banded rockfish
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 (メバル/鮴) in Japan and as bollak (볼락) 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 35.9 cm (14.1 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.
Sebastes inermis feeds on zooplankton. Males are territorial, establishing territories which range in area from 12 to 70 m2 (130 to 750 sq ft). The male initiates courtship when a female approaches their territory and perform a lateral display with rushing and turning movements being recorded frequently as part of the courtship. The courtship behaviour lasts for around 30 minutes before copulation. It climaxes with the pair ascending into the water column, 1.5 to 2.0 m (4 ft 11 in to 6 ft 7 in) above the seabed, the male suddenly coils around the body of the female to copulate.
