水温和体重对白斑红点鲑临界游泳速度和游动耗氧率的影响

为了揭示水温和体重对白斑红点鲑(Salvelinus leucomaenis)临界游泳速度和游动耗氧率的影响, 利用试验生态学方法测定了不同体重(1龄组、2龄组和3龄组)的白斑红点鲑在4、8、12、16、20和24℃共6个水温的临界游泳速度和游泳耗氧率。结果表明: 水温和体重对临界游泳速度的单独效应均显著(P0.05), 但水温和体重交互作用效应却不显著(P0.05), 在相同水温下白斑红点鲑临界游泳速度均随着年龄的增长(体重增加)而增加。水温4℃时3个年龄组白斑红点鲑临界游泳速度均最低, 分别为(21.61.06)、(22.930.61)和(30.271.29) cm/s, 随着水温的升高临界游泳速度均不断增加, 当水温升高到16℃时临界游泳速度达到最大值, 分别为(39.60.80)、(46.800.80)和(53.731.22) cm/s, 此后随着水温进一步升高到20℃, 临界游泳速度虽出现略微降低, 但经统计分析16℃和20℃时临界游泳速度无显著性差异(P0.05), 当水温达到24℃时却出现明显降低。水温和流速以及二者的交互作用对游泳耗氧率的影响均达到显著水平(P0.05), 白斑红点鲑在适宜的相同水温和流速时体重越大其游泳耗氧率越低, 整体观察3个年龄组白斑红点鲑鲑游泳耗氧率均随着水温和流速的增高而增高, 但当水温和流速升高到一定值游泳耗氧率却出现降低。研究得出体重较大的个体在相同水温下抵抗水流的游泳能力较强, 3个年龄组白斑红点鲑适宜的最高水温不应超过20℃, 最高流速依次不应超过32、40和48 cm/s。  

EFFECTS OF THE WATER TEMPERATURE AND THE WEIGHT ON THE CRITICAL SWIMMING SPEED AND OXYGEN CONSUMPTION RATE OF SALVELINUS LEUCOMAENIS

In this study, we applied ecological methods to measure the critical swimming speed and the oxygen consumption rate of three age groups of Salvelinus leucomaenis (one-year old, two-year old and three-year old) at different water temperatures (4, 8, 12, 16, 20, 24℃) and the flow velocity. The results showed that both the water temperature and the body weight had significant effects on the critical swimming speed (P0.05), however, the interaction between the two factors did not (P0.05). At the same water temperature, the critical swimming speed of Salvelinus leucomaenis increased along with the aging/increase in weight. At 4℃, the critical swimming speed was the lowest, which were (21.61.06) cm/s, (22.930.61) cm/s and (30.271.29) cm/s for the three groups respectively. The critical swimming speed increased along with the rise of the water temperature in all groups, and reached the maximum at 16℃, which were (39.60.80) cm/s, (46.800.80) cm/s and (53.731.22) cm/s for the three groups respectively. Then the speed slightly decreased as the water temperature rose to 20℃. However, there was no statistical difference in the speed at 16℃and at 20℃ (P0.05). When the water temperature further rose to 24℃, the critical swimming speed dropped significantly. The water temperature, the flow velocity and the interaction between these two factors displayed significant effects on the oxygen consumption rate (P0.05). Under the same suitable conditions, the oxygen consumption rate of Salvelinus leucomaenis significantly decreased as the weight increased. Overall, the oxygen consumption rates of the three groups were all increased with the rise of the water temperature and the flow rate, but the swimming oxygen consumption appeared to decrease when the water temperature and the flow rate reached a certain value. This study demonstrated that heavier individuals had higher swimming ability against the water flow given the same water temperature. The suitable water temperature for the three groups of Salvelinus leucomaenis should not exceed 20℃, and the maximum flow rate should be no higher than 32 cm/s, 40 cm/s and 48 cm/s for the three groups respectively.