Food habits of fishes in a seagrass bed on a fringing coral reef at Iriomote Island, southern Japan

To clarify the feeding habits of fishes in tropical seagrass beds on coral reefs, the gut contents of 53 fish species, collected in an Enhauls acoroides-dominated bed at Iriomote Island, southern Japan, were examined. Ontogenetic changes in food preference were recognized in 9 species, including lethrinids, mullids, pomacentrids, labrids, and scarids. Cluster analysis based on dietary overlaps showed that the seagrass fish assemblage comprised seven feeding guilds (small-crustacean, large-crustacean, plant, detritus, hard-shelled mollusc, fish, and planktonic-animal feeders). Of these, small-crustacean feeders were the most abundantly represented. On the other hand, planktonic-animal and hard-shelled mollusc feeders were each represented by only two species. Compared with previous studies on the feeding habits of temperate seagrass fishes, the present fish assemblage was characterized by larger species numbers of detritivores, herbivores, and piscivores and fewer planktonic-animal feeders.