Swimming Behavior of Isolated Ayu, Plecoglossus Altivelis Altivelis, in Running Water
Swimming behavior of isolated fish in static water has been investigated. Onitsuka et al3,4. Investigated on the swimming behavior of isolated ayu in static water. However, swimming behavior of isolated fish in running water has not been investigated. In this study, the swimming behavior of isolated ayu in the running water was recorded with a digital video camera with changing the velocity for five cases between 0-0. 70m/s. The area where the number of branch is more than 3 from starting point of ayu and distance from sidewall is more than one time of body length of ayu was defined as the universal area. Swimming along the sidewall after ayu arrived where distance from sidewall is less than one time of body length of ayu was defined as the wall area. Only a universal area is targeted in the analysis. The result showed that the swimming trajectory can be described by nodes and branches. The frequencies of the ground distance, swimming distance, ground speed, swimming speed, turning angle between each branch are modeled by the gamma distribution. It was found that the ground distance, swimming distance, ground speed and swimming speed in the streamwise direction increases with an increase of the flow velocity, because the ayu has positive rheotaxis. In contrast, the ground distance, swimming distance, ground speed and swimming speed in the spanwise direction is constant, irrespective of the flow velocity. The turning angle of swimming trajectory decreases with an increase of the flow velocity.
Kouki Onitsuka Juichiro Akiyama Hikaru Takeuchi Atsushi Ono
Department of Civil Engineering, Kyushu Institute of Technology, Kitakyushu, 804-8550, Japan
国际会议
南京
英文
152-158
2010-09-13（万方平台首次上网日期，不代表论文的发表时间）