盐度对斑节对虾耗氧率和窒息点的影响

Effect of salinity on the oxygen consumption rate and asphyxiation point of Penaeus monodon

为探讨盐度对斑节对虾(Penaeus monodon)呼吸代谢的影响,采用静水密闭式呼吸实验法,研究了不同盐度(10、15、20、25、30)和盐度骤降(从盐度25分别骤降至10、15、20)对斑节对虾[(2.74±0.50)g]的耗氧率和窒息点的影响。实验每组3个重复,每个重复6尾对虾,持续时间3 h。实验结果表明:随着盐度的升高,斑节对虾的耗氧率呈现先降低后升高的变化趋势,在盐度20时耗氧率达到最小值,但与盐度15和25相比耗氧率无显著性差异(P>0.05),盐度10和30时斑节对虾耗氧率显著上升(P<0.05);不同盐度与耗氧率的相关关系可用回归方程y=0.001x^2-0.0396x+0.8394(R^2=0.9674)表示。盐度从25骤降至20时,斑节对虾耗氧率与对照组(盐度25)相比无显著变化(P>0.05);盐度从25骤降到15和10时,斑节对虾耗氧率显著上升(P<0.05)。不同盐度和盐度骤降对斑节对虾窒息点的影响均不显著(P>0.05)。综上表明,通过呼吸代谢指标推测斑节对虾的最适生长盐度为20,在养殖生产中盐度骤降的范围要控制在10以内。

In order to investigate the effects of salinity on the respiratory burst of Penaeus monodon,different groups of salinity(10,15,20,25,30)and sudden salinity drop(from salinity 25 to 10,15,20)were set.We took a hydrostatic closed-breathing experiment to study the effects of salinity on the respiratory burst,including the oxygen consumption rate and asphyxiation point of Penaeus monodon.The Penaeus monodon used in the experiment was uniform with the body mass of(2.74±0.50)g.We repeated each group three times and each with six tails of Penaeus monodon.All experiments lasted for three hours.The results showed that salinity had significant effects on the oxygen consumption rate of Penaeus monodon(P<0.05),and the correlation between different salinities and oxygen consumption rate could be expressed by the quadratic equation y=0.001x^2-0.0396x+0.8394(R^2=0.9674).With the increase of salinity,the oxygen consumption rate of Penaeus monodon showed a trend of decreasing first and then increasing.When the salinity was 20,the oxygen consumption rate reached the minimum.When the salinity decreased from 25 to 20,there was no significant change in the oxygen consumption rate of Penaeus monodon(P>0.05).From 25 to 15 and 10,the oxygen consumption rate of Penaeus monodon increased significantly.The effects of different salinities and sudden salinity drops on the asphyxiation point of Penaeus monodon were not significant(P>0.05).By this study,we found that the optimal salinity for Penaeus monodon was 20,and the adaptation to salinity drop was within 10.Consequently,it is advisable to avoid sudden salinity change in breeding.