Diet of torrent catfish Liobagrus reini and fluvial sculpin Cottus pollux in the Aki River, Tokyo Metropolis

作者：Ogawa Hiromu^*; Katano Osamu; Yokota Masashi; Strussmann Carlos Augusto

来源：Nippon Suisan Gakkaishi, 2015, 81(3): 438-446.

DOI：10.2331/suisan.81.438

We investigated the diet of two benthic species, the torrent catfish Liobagrus reini and the fluvial sculpin Cottus pollux (large-egg type), from May 2013 to January 2014 in the Aki River, Tokyo, Japan. The diet was analyzed by volume of ingested prey animals and index of relative importance (IRI). Both species mainly preyed on Ephemeroptera, Trichoptera and Diptera. The catfish preyed on ephemeropteran nymphs selectively throughout the year, whereas the sculpin did not prey on it selectively in winter. The differences between the two species might result from different foraging tactics but their diets overlapped greatly in about half of the months examined. This fact suggests the potential for competition for food resources between them when benthic invertebrates are not abundant.

• 出版日期2015-5