マガレイおよびマコガレイの摂餌日周期について

日本水産学会

日本水産学会誌

In order to elucidate the diurnal feeding periodicity of Limanda herzensteini and L. Yokohamae, fourty-four stomach samples, comprising 2487 specimens, obtained with a trawl net in Mutsu Bay at different times in the day during May 1979 and May and October 1980 were examined. In both species, except for the matured fish of L. yokohamae, in autumn the mean number of main food organisms (Scalibregma inflatum and Paraprionospio sp.) in the stomach and stomach contents weight index (SCI=stomach contents weight×10^2/body weight) increased from about noon to evening, while the ratios of digested contents weight in the stomach (D=digested contents weight×10^2/stomach contents weight) decreased during the afternoon. These results show both species in autumn intook food chiefly from about noon to evening. In spring, however, it was clearly seen that the two peaks of feeding activity took place during forenoon and afternoon. The reason for the difference in diurnal feeding periodicity between seasons was not clear. But it seems likely that the variations in length of daytime and intensity of food requirement in relation to their physiological conditions is the main factor.

© 1982 公益社団法人日本水産学会