温度和重复运动对中华鲟游泳行为的影响

研究温度和重复疲劳运动对中华鲟游泳行为和能量代谢的影响,为中华鲟养殖环境水质量监测管理、物种保护和鱼道的设计等提供参考。在密封鱼类游泳装置中,利用速度递增法测定了不同温度(10、15、20和25℃)、流速条件下中华鲟(Acipenser sinensis)幼鱼(体长8.50~11.00 cm,体重5.10~8.80 g)的摆尾频率(TBF)、呼吸频率(RR),并同时测定了游泳过程中的耗氧率(M_(O_2))。结果表明:随着摆尾频率或呼吸频率的增加,中华鲟幼鱼的耗氧率增加,耗氧率与摆尾频率或呼吸频率呈指数相关(M_(O_2)=a×TBF~b;M_(O_2)=A×RR~B);随着温度增加,b值先减小后增加,15℃和20℃时b值较小;疲劳恢复后,第2次测试b值大于第1次;随着温度的增加,B值逐渐增加;疲劳恢复后,第2次测试B值小于第1次。游泳过程能量消耗随着温度的升高先降低后升高,15~20℃能量消耗较小。疲劳恢复后,第2次测试能量消耗大于第1次,游泳效率降低,特别是在10℃和25℃,15~20℃变化不明显。温度和重复游泳对中华鲟幼鱼游泳行为影响显著,温度不适宜和重复疲劳运动会产生叠加效应,导致游泳效率显著降低。

Effects of Temperature and Repeated Exercise on the Swimming Behavior of Chinese Sturgeon (Acipenser sinensis)

Temperature changes normally induce adaptations in the swimming behavior and physiology of fish. The aim of this study was to investigate the effects of temperature variation and repeated exercise on the swimming behavior of Chinese sturgeon (Acipenser sinensis).The study provides a reference for managing Chinese sturgeon aquaculture, species protection and fish passage design. Juvenile Chinese sturgeon (body length, 8.50-11.00 cm; weight, 5.10-8.80 g) were randomly assigned to four temperature treatment groups(10, 15, 20 and 25oC), with 15 individuals per group, and acclimated for one week. Swimming tests were carried out in a flume-type respirometer (60 cm×10 cm×10 cm), equipped with a video camera. The test began at an initial velocity of 0.03 m/s and a single fish was used in each trial. During the test, the velocity was increased by 0.5 BL/s at 30 min intervals until the fish reached fatigue. Dissolved oxygen (DO)in the respirometer was recorded every five minutes and the swimming behavior of the fish was recorded respectively for 5 min at minute 10 and 20 of each velocity interval. After a 60 min rest period another trial, using the same fish, was carried out under the same conditions. Swimming speed (U), tail beat frequency (TBF), respiration rate (RR) and oxygen consumption (MO2) of the Chinese sturgeon were determined by analyzing DO data and video recordings. The relationship of U to TBF and RR, and the relationship of MO2 to TBF and RR, at different temperatures were used to analyze the effect of temperature on the respiration rate and tail beat frequency of Chinese sturgeon. Both TBF and RR of Chinese sturgeon increased with swimming speed and, at a given speed, both increased with temperature. The MO2 increased exponentially with TBF and RR and the relationships were described, respectively, by the equations,MO2=a×TBFb and MO2=A×RRB.TBF and RR were found to be good predictors of the swimming speed and energy consumption of Chinese sturgeon during steady swimming. The value of b (the exponential coefficient of TBF) was higher for the second test than for the first test and, with increasing temperature, b initially decreased and then increased. The value of B (exponential coefficient of RR) for the second test was lower than for the first test and gradually increased with temperature. The energy consumption of Chinese sturgeon decreased and then increased with increasing temperature , and the energy consumption was lowest in the temperature range of 10oC - 25oC. The energy consumption of the second test was higher than that of the first test, and the swimming efficiency was lower, significantly lower at 10oC and 25oC. Temperature and repeated swimming significantly affect the swimming behavior of Chinese sturgeon and the additive effects of temperature outside the optimal and repeated fatigue significantly reduce the swimming efficiency of Chinese sturgeon.