温度梯度对四大家鱼临界游泳速度的影响

Effect of Temperature Gradient on the Critical Swimming Speed of Four Major Chinese Carps

中文关键词: 水温  鱼道  游泳能力  四大家鱼

英文关键词: Water temperature  Fishway  Swimming ability  Four major Chinese carps

中文摘要:

      在水利工程建设中，鱼道是一项重要的生态补偿措施，研究鱼类游泳能力可为鱼道等过鱼设施设计提供参考数据。本研究以四大家鱼为研究对象，分别测定其在不同温度(10℃、15℃、20℃、25℃和30℃)梯度下的临界游泳速度。结果显示，在10℃~30℃温度范围内，青鱼(Mylopharyngodon piceus)、草鱼(Ctenopharyngodon idellus)、鲢(Hypophthalmichthys molitrix)、鳙(Aristichthys nobilis)的相对临界游泳速度分别为(3.93±0.24~9.94±1.65) BL/s、(3.50±0.48~10.55± 2.07) BL/s、(0.95±0.04~4.68±0.58) BL/s、(2.22±0.18~3.95±0.23) BL/s [BL为实验鱼的体长(cm)]。在水温为10℃~20℃范围内，四大家鱼的绝对临界游泳速度和相对临界游泳速度均随水温升高而增大，基本表现为在20℃时达到最大值，随后趋于稳定，且20℃组四大家鱼游泳能力显著高于15℃组和10℃组，20℃组、25℃组和30℃组四大家鱼临界游泳速度均无显著性差异。此外，随着温度的升高，草鱼的游泳能力增加速度高于其他3种鱼。相同温度条件下，草鱼和青鱼的临界游泳速度相近，均极显著高于鲢和鳙(P<0.01)。当考虑过鱼对象为四大家鱼时，建议延长鱼道在夏季的开放时间，将鳙的临界游泳速度作为鱼道设计的主要依据。

英文摘要:

      Fishways are important ecological compensation measures that come with the construction of waterpower dams. Investigation of their swimming capability will provide the basis required for the design of fishery passage facilities. In this study, we used four major Chinese carp species to measure critical swimming speeds under five temperature gradients (10℃, 15℃, 20℃, 25℃, and 30℃). The results showed that the relative critical swimming speeds of Mylopharyngodon piceus, Ctenopharyngodon idellus, Hypophthalmichthys molitrix, and Aristichthys nobilis were (3.93±0.24)~(9.94±1.65) BL/s, (3.50±0.48)~(10.55±2.07) BL/s, (0.95±0.04)~(4.68±0.58) BL/s, and (2.22±0.18)~(3.95±0.23) BL/s, respectively, across 10℃~30℃. The absolute critical swimming speed and relative critical swimming speed of the four major Chinese carp species increased with the increase in water temperature at 10℃ to 20℃. The absolute critical swimming speed and relative critical swimming speed reached a maximum at 20℃, and then tended to stabilize. The swimming capability at 20℃ was significantly higher than that at 15℃ and 10℃, but was not significantly different from that at 25℃ and 30℃. In addition, the critical swimming speeds of C. idellus increased faster than that of the other three species of the four major Chinese carp, as the temperature increased. At the same temperature, the critical swimming speeds of C. idellus and M. piceus were similar, and significantly higher than those of H. molitrix and A. nobilis (P<0.01). Based on the results of this study, we suggest that the opening time of the fishway should be extended in the summer in the year, and the critical swimming speed of A. nobilis should be taken as the main basis during fishway designing.