Interspecific comparisons of growth and diet among late larvaeof three co-occurring clupeoid species in the Kii Channel, Japan

摘要

Growth and diet were compared among larvae of Japanese anchovy Engraulis japonicus, Japanese sardine Sardinops melanostictus and Pacific round herring Etrum-eus teres. Compositions of prey items of the three species in the same month showed greater similarity than for the same species in different months. Prey size as well as prey taxa of the three species overlapped considerably with one another. Therefore, interspecific prey competition is likely in the case of limited food availability. The most abundant species tended to change from anchovy to round herring in early winter, from round herring to sardine in late winter and from sardine to anchovy in early spring, indicating a temporal segregation in use of the nursery grounds. Similar seasonal changes in growth rates were observed for the three species. Although interspecific prey competition is likely, the temporal segregation and similar temporal changes in growth rates could favor their coexistence.