In order to evaluate seed quality for release projects, body constituents of artificially-produced black sea bream Acanthopagrus schlegeli were monitored after release. The individually marked fish (42 mm in total length) were released into a Daio Bay of Nino-shima Island, Hiroshima, in August 1993. The hatchery-produced fish which had high lipid reserves lost them abruptly within one month af ter release. Thereafter, the lipid level became lower than that of wild fish at the 100th day. Intestinal length of hatchery-produced fish was shorter than that of wild fish, but extended to the same length to wild fish by living in the sea. Activity of the hepatic enzyme glucose-6-phosphate dehydrogenase (EC 1.1.1.49) involved in lipogenesis was higher in hatchery-produced fish but reached the same level as that in wild fish at one month after release. Activity of hepatic 6-phosphogluconate dehydrogenase (EC 1.1.1.44) remained constant during the experimental period. The changes in the body constituents could be helpful in evaluating fish quality in releasing projects.

Black sea bream Acanthopagrus schlegeli having 42mm in body length as seed for release project were compared with the same size of wild fish. Hatchery-produced fish had shorter intertinal length and higher lipid reserves in muscle, hepatopancreas, and intraperitoneal fat body compared with wild fish. Lipogenic enzyme activities of liver, glucose-6-phosphate dehydrogenase (EC 1.1.1.49) and 6-phosphogluconate dehydrogenase (EC 1.1.1.44) showed a tendency to be higher in hatchery -produced fish. The different intestinal length and lipid metabolism which were caused during rearing conditions would be associated to seed quality for the release project.