EFFECTS OF POSITION OF A WHITE LAMP ON SWIMMING CHARACTERISTICS OF AYU IN STATIC WATER

Abstract

 Visual information is one of the factors that fish decides actions, so taking control of their behavior by light has been considered. It is thought that reactions against light are depending on fish species. Inoue et al. pointed out that river fish had a stronger tendency to dicide the swimming position by taking advantage of visual information than oceanic fish. However, effects of light on fish have not been investigated well. In this study, the position of an installed white lamp in the rectangle pool was changed and swimming characteristics of ayu in static water were analysed. It was found that there were few effects on the radius of fish school. On the other hand, the swimming speed increased and ayu got away from the white lamp with the white lamp approaching the bottom in the rectangle pool.