抄録
Fish can see not only the visible rays of light for human being but also the ultraviolet rays. However, the effects of the ultraviolet rays on the fish behavior have not been investigated. It is known that the reaction of fish against the reflected light and transmitted light is different irrespective of the same species. In this study, the effects of the reflected ultraviolet light and transmitted ultraviolet light on the fish behavior were investigated experimentally. It was found that the reflected ultraviolet light by the side and bed wall has no effect on the fish behavior. In contrast, the ayu swims under the irradiated area of ultraviolet light by choice.
