Abstract
The purpose of this study is to grasp living conditions of freshwater fishes and those habitats in irrigation channels of urbanizing area, to demonstrate the factors that influence habitat of freshwater fishes. This study was carried out in four seasons from December 2001 to November 2002 on Hino-channel, Ne-river, Toyoda-channel and Mukoujima-channel flowing through Hino-city. Objectives of the survey were fishes, hydraulic conditions, water qualities and physical environment of channels. In summer, juvenile and immature of Carassius carrassius subsp. 1, Misgurs anguillicaudatus and Gnathopogon elongatus appeared in large quantities at the sampling site that was located near paddy fields locally. Connections between channels and the paddy fields enabled fishes to migrate from channels to the paddy fields upward. It is suggested that the paddy fields have function of spawning and growing of juvenile and immature of fishes living in the channels. The decrease in water depth at lower of reaches has negative influence on habitat of fishes in winter.
