中文摘要：

以草鱼幼鱼(体长8.0~9.7cm,体重9.6~13.4g)为研究对象,采用实验室专利装置研究了不同运动消耗状态下的草鱼幼鱼游泳能力。结果表明:在正常状态下草鱼幼鱼的临界游泳速度(Ucrit)为7.11±0.60BL/s,耗氧率(MO2)与流速(U)方程拟合为MO2=470.5+41.9U1.23,耗氧率随着流速的增大而增大,且草鱼的有氧运动效率较高。在4种运动消耗状态(0.6Ucrit、0.8Ucrit、1.0Ucrit、1.2Ucrit)流速下运动1h草鱼的消耗后临界游泳速度(Upcrit)分别为:7.25±1.35、6.33±0.6、6.26±0.8、5.60±0.4BL/s,临界游泳速度随着前期消耗流速的增大而减小,相应的耗氧率方程拟合为:MO2=382.69+46.5U1.44,MO2=445.26+42.23U1.46,MO2=466.11+47.90U1.49,MO2=600.34+38.83U1.51。运动消耗会导致草鱼的有氧运动效率降低,同时随着运动消耗速度的增加有氧运动效率随之降低。研究结果认为在设计以草鱼为主要过鱼对象的过鱼设施时,鱼道内的流速不应大于0.8Ucrit,以使鱼类顺利通过。针对不同过鱼对象游泳特性进行设计的鱼道能够提高鱼类通过鱼道的效率。

英文摘要：

Natural population of grass carp,a species of Cyprinidae commonly found in China,has been declining in recent years.Interruption of free flowing river by dams is one of the important factors.The degree of fatigue influences fish swimming capability and determines whether the fish could pass the fishways.To understand the effect of fatigue degree on swimming capability of grass crap,a laboratory study was conducted in a flume-type respirometer equipped with a high speed video camera system to record swimming behavior.The fish,body length (BL) ranging from 8.0 to 9.7 cm and body mass ranging from 9.6 to 13.4 g,were selected in experiment.The critical swimming speed (Ucrit) was 7.11 ±0.6 BL/s in the control group.A power function accurately describes the relationship between oxygen consumption rate (MO2) and swimming speed (U).The function was MO2 =470.5 + 41.9 U1.23 (R2 =0.976),showing oxygen consumption increased with swimming speed.The critical swimming speeds after activity cost (Upcrit)were compared futher.Four kinds of different previous activities cost (0.6/0.8/1.0/1.2 Ucrit,in one hour) were measured at the 18±1℃.The Upcrit was found to be 7.25±1.35,6.33±0.60,6.26± 0.80,and 5.60±0.42 BL/s,respectively.It is found that Upcit was mostly smaller than Ucrit,while the cost speed was greater than 0.8 Ucrit.The fish fatigue at high flow rate used great proportion of anaerobic metabolism and led to a large number of lactic acid accumulation,resulting in a big percentage of anaerobic metabolism.This would damage the swimming system.The function of oxygen consumption rate was described as:MO2 =382.69+46.5U1.44,MO2 =445.26+42.23U1.46,MO2 =466.11+47.90U1.49 and MO2 =600.34+38.83U1.51.The speed exponents indicate that the efficiency was becoming lower with increase of velocity during activity cost period.It is therefore suggested that continuous swimming would not be harmful to swimming capability when the swimming speed was lower than 0.8 Ucrit.This investigation is expected to provide the basic science of fish