We conducted a field survey in 8 tributaries of the Shigenobu River to elucidate the influence of catchment land use on fish and invertebrate assemblages and feeding habit of fish. Fish and invertebrate assemblages were dominated by high-temperature and pollution tolerant taxa in agricultural streams. Dominant omnivorous fish, Phoxinus oxycephalus jouyi, selectively fed on periphyton in agricultural streams while it utilized various food items in forest streams. We concluded that changes in water temperature and nutrient concentration would generate synchronous changes in community structures of fish and invertebrates and, moreover, fish feeding, along the forest-agricultural gradient.
