土佐湾の砕波帯に出現するアユ仔稚魚の食性
1988 年 35 巻 3 号 p. 382-388
詳細
1988 年 35 巻 3 号 p. 382-388
A total of 7, 000 larval and juvenile Plecoglossus altivelis was collected at semimonthly intervals with a small seine in a surf zone of Tei beach facing Tosa Bay during the period of June 1982 to May 1983. They occurred in the surf zone from middle October to middle May. About 500 larvae and juveniles (10.9-59.9 mm TL) were used to examine their feeding habit. The feeding incidences by collection dates fluctuated from 0 to 100%, with 90.6% in total incidence. They fed mainly on copepods (e.g. Paracalanus parvus and Oithona spp.) throughout postlarval and juvenile stages, while they first took small benthic animals at 53.0mm TL. Their food compositions were influenced fundamentally by the planktonic fauna of the surf zone, but larvae under 20mm TL tended to take relatively larger copepods.
