好漁期から不漁期への移行期における東京湾産シャコ幼生の時空間分布

概要

論文の詳細を見る
Commercial catch of the Japanese mantis shrimp Oratosquilla oratoria (Stomatopoda, Squllidae) in Tokyo Bay was high during 1980s (good catch period), but dropped dramatically around 1992 and continued to be low during the 1990s (poor catch period). The major peak of larval abundance of O. oratoria appeared in June/July during the good catch period, while it appeared in August/September during the poor catch period. In the present study, we examined the temporal distribution of O. oratoria larvae during the transition from good catch period to poor catch period in Tokyo Bay. The larvae occurred from June to November, with a minor peak in July and a major one in September. The appearance of this major peak in September was considered to be an indication of the coming poor catch period. All of the eleven larval stages were collected during the research period. Stage-III larvae that were the first phase of pelagic life were numerically dominant. The propelagic-stage larvae (stages I and II) occurred only from June to September, while the larvae in the final stage of the planktonic phase (stage XI) occurred from July to November. Total duration of the larval phase was estimated to be one to two months.
鹿児島大学の論文
2005-12-27