温度对白斑狗鱼耗氧率、窒息点及主要生化指标的影响

在不同温度下,测定了平均体重为(597.2±96.3)g的白斑狗鱼(Esox lucius)的呼吸耗氧率、窒息点及主要生化指标。结果显示:在水温为3℃、8℃、13℃和18℃下,白斑狗鱼的耗氧率随着温度的升高而显著上升(P<0.05)。3℃时耗氧率最低;为(0.0047±0.000017)mg/g.h,18℃时耗氧率最高;为(0.029±0.0011)mg/g.h。当水温在13℃时,白斑狗鱼的昼夜平均耗氧率在(0.020±0.0031)mg/g.h,15:00耗氧率最低,11:00耗氧率出现最高值。Q10值的变化显示白斑狗鱼的耗氧率对温度具有敏感性,13～18℃时,Q10最小,此温度为白斑狗鱼的较适生长温度。在高温下(18℃),白斑狗鱼呼吸急促,呼吸频率达到(68.50±3.58)次/min;在低温下(3℃),白斑狗鱼呼吸缓慢,呼吸频率下降到(29.00±4.31)次/min。白斑狗鱼的窒息点随着水温的升高而增大,水温为13℃,其窒息点最高为1.68 mg/L,水温为3℃时,其窒息点最低为0.82 mg/L。随着水温的不断上升,白斑狗鱼的肝糖元含量、肝胰脏中的乳酸含量显著减少(P<0.05)。肝糖元含量由(67.70±6.66)mg/g降至(41.83±3.72)mg/g。乳酸含量由(0.36±0.0041)mmol/gprot降至(0.15±0.0034)mmol/gprot。肝胰脏中的碱性磷酸酶、酸性磷酸酶的酶活力随着水温的升高而小幅缓慢下降,分别由(21.51±0.69)U/gprot和(22.34±0.43)U/gprot降至(19.04±0.62)U/gprot和(18.10±0.41)U/gprot。

Effects of temperature on the oxygen consumption rate,asphyxiation point and biochemical indices of Esox lucius

Under different temperatures,the oxygen consumption rate,asphyxiation point and biochemical indices of Esox lucius were studied by the method of respiratory chamber.The results showed that:Under different temperature of 3 ℃,8 ℃,13 ℃ and 18 ℃,the oxygen consumption rates of Esox lucius increased immediately as temperature rose(P<0.01),(0.0047±0.000017)mg/g·h was the lowest oxygen consumption rate at 3 ℃,(0.029±0.0011)mg/g·h was the highest oxygen consumption rate at 18 ℃.Under constant temperature of 13℃,the mean oxygen consumption rate of Esox lucius which had average body weight(653.8±88.1)g was(0.020±0.0031)mg/g·h.The lowest oxygen consumption rate was at 3:00pm,and the highest oxygen consumption rate was at 11:00am.The change of Q10 value proved that oxygen consumption rate was sensitive to temperature.Q10 was minimum at 13~18 ℃,this temperature was optimum to growth of Esox lucius.The higher the temperature,the faster the breathing was.At 18 ℃ respiratory frequency of Esox lucius was(68.50±3.58)(time/min),the minimum was(29.00±4.31)(time/min) at 3 ℃.The suffocation point of Esox lucius increased with the increasing of water temperatures.The suffocation reached the highest point of 1.68 mg/L at 13 ℃ and reached the lowest point of 0.82 mg/L at 3 ℃.The contents of hepatic glycogen decreased immediately with the increasing of water temperatures(P<0.05),from(67.70±6.66)mg/g to(41.83±3.72)mg/g.The content of lactic acid also decreased immediately with the increasing of water temperatures,from(0.36±0.0041)mmol/gprot to(0.15±0.0034)mmol/gprot.The activity of acid phosphatase and alkaline phosphatase weakened in the hepatopancereas when the water temperatures increased,from(21.51±0.69)U/gprot and(22.34±0.43)U/gprot to(19.04±0.62)U/gprot and(18.10±0.41)U/gprot,respectively.