应用于鱼道设计的玉曲河流域裸腹叶须鱼游泳能力探究

Swimming Ability of Ptychobarbus kaznakovi in Yuqu River Basin Applied to Fishway Design

探究西藏玉曲河流域裸腹叶须鱼(Ptychobarbus kaznakovi)的游泳能力,可为珍稀鱼类资源保护及鱼道设计提供理论参考。以体长(BL)18~27 cm的裸腹叶须鱼为研究目标,在野外场景下分别测试其感应流速、临界游泳速度、突进游泳速度和持久游泳速度。结果表明:(1)裸腹叶须鱼的感应流速为(0.17±0.01)m/s,平均相对感应游泳速度为(0.78±0.07)BL/s;临界游泳速度为(0.92±0.16)m/s,平均相对临界游泳速度为(4.33±1.20)BL/s;平均突进游泳速度为(1.28±0.39)m/s,平均相对突进游泳速度为(5.81±1.81)BL/s;(2)流速(V)对裸腹叶须鱼的持续游泳时间(T)有显著性影响,持续游泳时间均随设定流速的递增而明显下降,耐力关系可拟合为:lgT=-5.30V+6.39,游泳速度(V_(s))、鱼道总长度(d)和鱼道内最大流速(V_(f))关系式为:V_(f)=V_(s)-d×10^((5.3Vs-6.39));(3)裸腹叶须鱼的趋流率(P_(re))与流速(V)拟合关系式为:P_(re)=14.23V-2.51,得出95%裸腹叶须鱼的趋流速度为0.18 m/s;(4)以裸腹叶须鱼为主要过鱼目标时,建议鱼道进口的设计流速为0.9~1.3 m/s,进口的主流长度为2~4 m,鱼道出口流速不低于0.2 m/s,鱼道池室主流流速为0.2~0.8 m/s。结合鱼类在竖缝处的不同上溯模式和持久游泳速度,推荐池室主流长度最大应为5.5 m,竖缝处最大平均流速为1.1 m/s,鱼道长短隔板沿水流方向的最大间隔为0.4 m。研究结果可为玉曲河鱼道关键部位的长度设计和流速要求提供基础数据支撑。

In this study,we investigated the swimming ability of Ptychobarbus kaznakovi in the Yuqu River basin of Tibet,aiming to provide basic parameters for fishway design and to enrich fish behavior research for the species.P.kaznakovi of body length(BL)18-27 cm from the Nujiang River basin were selected for testing.Testing was carried out in a flume in the field and included induced swimming velocity,critical swimming speed,burst swimming speed and sustained swimming speed.Results show:(1)The flow rate that induced P.kaznakovi to swim was(0.17±0.01)m/s,and the average relative induced swimming speed was(0.78±0.07)BL/s;the critical swimming speed was(0.92±0.16)m/s,and the average relative critical swimming speed was(4.33±1.20)BL/s;the average burst swimming speed was(1.28±0.39)m/s,and the average relative burst swimming speed was(5.81±1.81)BL/s.(2)Water velocity(V)had a significant effect on sustained swimming time(T),which decreased significantly as water velocity increased.The relationship between sustained swimming time and water velocity can be described as lgT=-5.30V+6.39,and the relationship between the swimming speed(V_(s)),total length of the fish passage(d)and the maximum water velocity(V_(f))in the fish passage was described as V_(f)=V_(s)-d×10^((5.3Vs-6.39)).(3)The relationship between the rheotaxis rate(P_(re))and flow velocity for P.kaznakovi fit the equation P_(re)=14.23V-2.51,and the flow rate at 95% P_(re) was 0.18 m/s.(4)If P.kaznakovi is selected as the target species for a fish passage,we recommend an inlet flow velocity of 0.9-1.3 m/s,an inlet length of 2-4 m,an outlet flow velocity of no less than 0.2 m/s,and a mid-channel flow velocity in the resting pond of 0.2-0.8 m/s.Based on the upstream migration pattern and sustained swimming speed of the test fish,we recommended a maximum pool chamber length of 5.5 m,a maximum average flow velocity at the vertical slot of 1.1 m/s,and a maximum spacing of 0.4 m between the long and short baffles.Our results provide basic data to support the protection of a rare fish and design criteria for the lengths and flow velocities of fishways in the Yuqu River basin.