抄録
1. This report deals with the result of study on the contents of the alimentary canals of Salvelinus leucomaenis pluvius and Oncorhynchus masou f. mason fished in small branches of the Ina-gawa River System, Fukushima Prefecture in July and August of 1965.
2. As surface baits, that is the baits of air and land origin, Coleoptera including scarabaeids, cerambycids, coccinellids, carabids, chrysomelids, etc. and Hymenoptera including formicids and ichneumonids were found most abundantly in the alimentary canals.
3. As water baits, Trichoptera and Ephemeroptera were found most abundantly.
4. The alimentary canal of Salvelinns sample No. 1 was filled with 8 individuals of diplopods. This fact suggests that the Salvelinus came to the edge of the brook and took the animals living on the wet earth.
5. The alimentary canal of Selvelinus No.3 was filled with 76 larvae of Neophylax sp. (Trichoptera), and that of No.4 with 56 larvae of the same species. Because of the larvae of this caddis-fly often coming together on the stone of the riffle, it seems that the fishes have attacked the group of the larvae.
