FOOD UTILIZATION OF ADULT FLATFISHES COOCCURRING IN THE BOHAI-SEA OF CHINA

Stomach contents were examined of 4527 adult individuals of 12 flatfis h species collected during the 1982 - 1983 Bohai Sea Fisheries Resourc es Investigation. Their food habits, diet diversity, similarity of pre y taxa, trophic niche breadth and diet overlap were systematically ana lysed. Ninety-seven prey species belonging to the Coelenterata, Nemert inea, Polychaeta, Mollusca, Crustacea, Echinodermata, Hemichordata and fish were found and five of them were considered to be principal prey for flatfishes: Alpheus japonicus, Oratosquilla oratoria, Alpheus dis tinguendus, Loligo japonicus and Crangon affinis. Among the flatfishes , Paralichthys olivaceus was piscivorous, whereas Pseodopleuronectes y okohamae and Pseudopleuronectes herzensteini both had polychaetes and molluscs as their main prey groups. Pleuronichthys cornutus was classi fied as a polychaete-mollusc eater, with a strong preference for crust aceans. Verasper variegatus, Cynoglossus semilaevis, Eopsetta grigorje wi and Cleisthenes herzensteini ate crustaceans. Kareius bicoloratus w as classified as a mollusc-crustacean eater: Cynoglossus abbreviatus, Cynoglossus joyneri and Zebrias zebra were grouped as crustacean-fish eaters. However, Z. zebra also took polychaetes and C. abbreviatus and C. joyneri preyed on some molluscs. Trophic relationships among the f latfishes were complicated, but they occupied distinctive microhabitat s in different seasons and selected their specific prey items, which w as favourable to the stability of the flatfish community in the Bohai Sea.