ECOLOGICAL STUDIES ON THE JAPANESE SEA-BASS, LATEOLABRAX JAPONICUS-I

Abstract

The Japanese sea-bass, Lateolabrax japonicus, a valuable food fish, changes the main food from Mysis to shrimps in autumn of the first year of life in Matsushima Bay. After emigrated to the coastal open sea, the species mainly eats fishes and shrimps, raising the trophic niche as the fish grows larger. Considering from the results of feeding experiments the fish in nature does not usually eat as much as it can eat, and this will be caused from an insufficient share of natural feed. The following species can be enumerated as supreme competitors in feeding; Pseudoblennius cottoides and Hexagrammos otakii in the Zostera area, and Sebastes oblongs and Sebastes schlegeli outside of the Zostera area.