抄録
Sampling of megabenthos was conducted between 1997 and 1998 in Ise Bay, central Japan to examine the food habits of three dominant species of crabs: Charybdis bimaculata, Paradorippe granulata, Cancer gibbosulus. The degree of gut fullness as well as the frequencies of occurrence and the relative volumes of food items were investigated. In the summer when the oxygen-poor water conditions developed, frequencies of occurrence of food items were low and the degree of the guts fullness in most of crabs collected was <50%; in contrast, these values were high from the winter to spring of the following year, when the oxygen-poor water conditions did not develop. A comparison between frequencies of occurrence and relative volumes of food items in the gut showed that crustaceans, polychaetes, gastropods and bivalves were important foods for the crabs. The main components of the gut contents were different between the three species, though this is probably due to differences in spatial distribution patterns of crabs and their prey items.
