Deformity of agglutinated pelvic fin membrane in hatchery-reared black rockfish Sebastes inermis and its application for stock separation study |
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| Authors: | Tomoya MURAKAMI Satoshi AIDA Kouji YOSHIOKA Tetsuya UMINO AND Heisuke NAKAGAWA |
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| Institution: | Hiroshima Prefectural Fisheries Experimental Station, Aki, Hiroshima 737-1207 and;Graduate School of Biosphere Science, Hiroshima University, Higashi-hiroshima, Hiroshima 739-8528, Japan |
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| Abstract: | ABSTRACT: This study is the first to report on the high occurrence of agglutinated pelvic fin membrane deformities in hatchery-reared black rockfish Sebastes inermis . For 5 years, this symptom was marked in hatchery-reared fish, with 58.7% of fish deformed on average (varying between 46.7 and 72.0%). The deformity was a peculiarity in hatchery-reared fish, but is negated in wild fish, and was not related to whether the fish broodstock originated from the wild or from a hatchery. Mark–release experiments showed that deformed fish were almost the same as normal hatchery-reared fish in growth and survival rates, and, theoretically, the recapture numbers of hatchery-stocked fish, estimated by deformity, almost coincided with actual recapture numbers, confirmed by otolith tagging. The results of the present study indicate that deformity in hatchery-reared black rockfish is useful as a stock separation tool. |
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| Keywords: | black rockfish deformity otolith tagging pelvic fin stock separation |
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