EXPERIMENTAL STUDY ON BURST SPEED OF FISH IN STATIC WATER

Fish can migrate through fishways, when the maximum velocity in fishways is smaller than fish's burst speed. The burst speed depends on fish kind, body length of fish and flow velocity. Although, there is little information on the burst speed, it is known that burst speed is nearly estimated as ten times of body length. In this study, investigation on the burst speed of several fish kinds, i. e., zacco temminckii, zacco platypus, carassius aurafus and plecoglossus altivelis altivelis, in the condition that flow velocity is zero was conducted. It was found that the swimming speed increases rapidly after starting swimming and acceleration decreases gradually. Finally, the swimming speed reaches to the burst speed. A new formula which can predict the swimming speed is suggested. The approach time and swimming acceleration before reaching the burst speed are also investigated on the basis of a suggested formula.