福井県北部沿岸の底生性魚類 : II. マエソ, ヒメジおよび異体類3種の食性

1983年10月28、29日に福井県沿岸で採集された、マエソ、ヒメジ(共に幼魚)、ダルマガレイ(未成熟)、アラメガレイおよびササウシノシタ(共に成魚)の食性について調べた。幼魚であるマエソ、ヒメジはすでに種特有の胃の形状を呈していた。5種の体長に対する、胃内容物重量と、胃内容物重量指数の関係を明らかにした。5種の餌生物については、すべての種に摂食されていたエビ類をはじめ、4種に摂食されていた介形類、キクロプス類、カニ類、魚類など18種類が確認されたが、各種の主たる餌生物は、マエソが魚類とエビ類、ヒメジがキクロプス類とエビ類、アラメガレイがキクロプス類、ダルマガレイがエビ類とカニ類、そしてササウシノンタはヤドカリ類とキクロプス類であった。

Food habit on Sauricla undosquais (young), Upenus bensasi (young), Turphops oligolepis (adult), Engyprosoporz grandisquama (immature) and Heteromycteris japonicus (adult) was examined, which were caught in the waters of the coast of Fukui Pref. on October 28th and 29th, 1983. Each sample of S, undosquairzis and U. bensasi had already had a form of stomach proper to it (Fig. 1). Relationships between body length and stomach contents weight were clarified and feeding indexes were calculated on each predator species (Fig. 2). The 18 items of preys were identified from stomachs of five species of predator examined. Shrimps were taken by all species, and ostracods, Cyclopoida, crabs and fishes were been feeding by four species (Table 1). Main preys of each predator species of examined fishes were summarized below: (a) fisher and shrimps by S. undosquarmis; (b) Cyclopoida and shrimps by U. berzsasi; (c) Cyclopoida by T. oligolepis; (d) shrimps and crabs by E. grarzdisquama; (e) Cyclopoida and pagurians by H. japonicus (Table 2). In the inter-specific relation of five predator fishes, the existence of the larger competition in connection with Cyclopoida and shrimps was estimated (Fig. 3).