2026-03-12T01:25:16Z https://fra.repo.nii.ac.jp/oai

oai:fra.repo.nii.ac.jp:02008238 2025-12-10T06:48:32Z 12:14:1716951205967

平戸島志々伎湾における人工マダイ放流魚の動向と順応過程 Movements and Adaptation Process of Artificially-reared Red Sea Bream after Release in Shijiki Bay, Hirado Island Matsumiya, Yoshiharu 松宮, 義晴 マツミヤ, ヨシハル Kiso, Katsuhiro 2066 木曾, 克裕 90372010 キソ, カツヒロ In order to find the movements and adaptation process of artificially-reared red sea bream after release and to see about the influence of this operation on wild red sea bream in Shijiki Bay, 14677 artificially-reared fish of about 70 mm in fork length were released concentratedly at the location where wild red sea bream were thickly distributed. From the end of July during the period of about a month recapture-follow-up was conducted throughout the whole bay area and the following results were obtained : (1) Two days after the release, the number of wild red sea bream captured in the releasing site was found to be extremely small and less than one-tenth of what it had been before the release. Many of both, wild fish and recaptured released fish, were found with empty stomachs, and the first ones showed an abnormal feeding habit. This seems to indicate the possibility that the large quantity of released fish had a considerable influence upon the wild ones, especially in the releasing site. (2) Five to nine days after the release, the distribution and feeding habit of wild red sea bream resumed their normal conditions. In this period, the rate of empty stomach in the released fish decreased, and also the composition of stomach contents in the released fish showed a step-by-step-resemblance to that of wild fish. (3) The released fish slowly moved and dispersed from the releasing site, and five days after release, they were considerably well mixed with the wild fish. The rate of recaptures to released fish was 1.49%. The total decrease rate per day in released fish was calculated 8.4%, and it was pretty higher than that of wild fish. In this research, the recapture rate, survival rate and growth of the released fish in this area were fairly lower in comparison with the published results from other water areas. departmental bulletin paper 西海区水産研究所 Seikai Regional Fisheries Research Laboratory 1982-10 西海区水産研究所研究報告 58 89 98 Bulletin of the Seikai Regional Fisheries Research Laboratory AN00393385 0582-415X https://fra.repo.nii.ac.jp/records/2008238 jpn snf_k_58_89 日本農学文献記事索引(agriknowledge) https://agriknowledge.affrc.go.jp/RN/2010272456 metadata only access