Distinct foraging modes between two stream-dwelling benthic fishes, torrent catfish Liobagrus reini and Japanese fluvial sculpin Cottus pollux (large-egg type)

摘要

We observed feeding behavior, movement, focal point utilization, and diet of two stream-dwelling benthic fishes, torrent catfish Liobagrus reini and Japanese fluvial sculpin Cottus pollux (large-egg type), under experimental conditions. Torrent catfish are benthos feeders, cruise widely, and prey exclusively on chironomid and trichopteran larvae. Japanese fluvial sculpin are drift and benthos feeders, ambush prey, and select for ephemeropteran nymphs in addition to chironomid and trichopteran larvae. The different foraging modes of these two species might enable their sympatric distribution when their diets overlap.