鳙(花鲢)在自然环境中分布于中国南部流域至阿穆尔河,是重要的经济性鱼类,具江湖生殖洄游特性。大坝建设阻碍了其洄游产卵繁殖通道,导致自然环境中其繁殖力的下降,需要有效的过鱼设施帮助鳙通过大坝等水流屏障。为了设计高效的鱼道引导鳙通过,本文通过自制密封的鱼类游泳实验装置,研究了鳙幼鱼游泳能力。测定了5个温度(5、10、15、20和25℃)下鳙幼鱼的临界游泳速度。通过测定不同温度下,疲劳前后血清总蛋白(TP)、血糖(GLU)和甘油三酯(TG)含量,评价疲劳运动引起的生理胁迫。结果表明,在试验温度范围内,随着温度的升高,临界游泳速度显著提高(P〈0.05)。25℃时临界游泳速度最大,为7.01 BL/s(1.19 m/s)。在疲劳运动后,血清总蛋白、血糖和甘油三酯含量显著升高(P〈0.05)。水温低于15℃与高于15℃相比,鳙疲劳运动后血清总蛋白、血糖和甘油三酯含量显著升高。以鳙幼鱼为研究对象,研究了非适宜温度环境和疲劳运动胁迫下鱼类的生理反应。以期为鱼类生理学研究和渔业保护管理等领域提供理论依据,为制定有效的鱼道提供数据参考。
Aristichthys nobilis(bighead carp) is a commercially valuable fish with a natural range extending from southern China to the Amur River.Dams interfere with spawning migrations and reproduction in wild populations has declined and effective fish passages are needed.To obtain data for the design of effective fish passages for A.nobilis,a laboratory study of the swimming ability of juvenile A.nobilis was conducted in a flume-type respirometer.Critical swimming speed(Ucrit) was determined at five temperatures(5,10,15,20 and 25℃) and Ucrit increased significantly(P<0.05) with increasing temperature,reaching a maximum of 7.01 BL/s(1.19 m/s) at 25℃.The physiological stress caused by swimming to fatigue was assessed by measuring serum levels of total protein(TP),blood glucose(Glu) and triglyceride(TG) before and after fatigue at 5,10,15,20 and 25℃.At fatigue,serum levels of TP,Glu and TG were significantly higher(P<0.05) than before fatigue.Furthermore,when the water temperature was below 15℃,serum levels of TP,Glu and TG tested at fatigue were significantly higher than those tested at fatigue in water above 15℃.This investigation provides data on the physiological response of A.nobilis to exercise fatigue and the effect of environmental stress produced by suboptimal temperature.Results will contribute to the fields of fish physiology and conservation management and provide information valuable for designing effective fish passages.