GONG Li, WU Yihong, BAI Yinbaoligao, MU Xiangpeng

State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing 100038, China

Abstract: The swimming capability and swimming behavior of the juvenile grass carp (bl=5.0~15.0 cm) were tested using experiment apparatus by increasing velocity method at 28±1 ℃. The results show that the critical swimming speed of juvenile grass carp ranges from 68 to 100 cm/s. There is a significant linear correlation between the critical swimming speed and fish body length, and the fitting function is described as Ucrit=0.04BL+0.476. According to the response of fish swimming behavior to the flow velocity, fish need to constantly adjust their behavior to adapt to the environment with the increasing of flow velocity. Their tail beat frequency (TBF) is roughly proportional to rising, and the entire testing process can be divided into four stages. The maximum swimming speed of each stage is about 45.6 %, 82.8 %, 95.9 % and 100 % of the critical swimming speed, respectively. The research results complement the swimming capability gaps of the four major chinese carps (FMCC) , and provide an important reference for the hydraulic design of fishway.

Key words: swimming capability; swimming behavior; juvenile grass carp; critical swimming speed; fishway

Published in: Journal of China Institute of Water Resources and Hydropower Research, Vol. 13, No. 3, June 2015