高盐突变对凡纳滨对虾(Litopenaeus vannamei)生长性能及相关酶活力的影响

为模拟夏季水分蒸发水体盐度快速升高对凡纳滨对虾(Litopenaeusvannamei)生长性能及理化调节的影响,试验设置盐度从30突变至35、40、45、50、55及60,以盐度30为对照,突变盐度下养殖28d,每7d检测凡纳滨对虾的存活率、相对增重率、体长增长率,试验结束时检测血清Na+/K+-ATP酶、总ATP酶、碱性磷酸酶(AKP)、酸性磷酸酶(ACP)和超氧化物歧化酶(SOD)活力。结果表明,高盐突变显著抑制凡纳滨对虾的存活率和相对增重率(P0.05),随着突变盐度的升高,凡纳滨对虾的相对增重率逐渐降低,60盐度组仅为对照组的15.53%。盐度突变至50后,凡纳滨对虾存活率显著下降。随着高盐突变幅度的增加,Na+/K+-ATP酶和ACP酶活力受到显著影响(P0.05),其中Na+/K+-ATP酶活力逐渐上升,在突变60盐度时表现为最高;ACP酶表现为先上升再下降的单峰变化趋势。总ATP酶、SOD酶、AKP酶受影响不显著(P0.05)。结果表明,高盐突变幅度越大,凡纳滨对虾存活率越低、生长越缓慢,Na+/K+-ATP酶活力升高,渗透调节能力增强,ACP酶活力升高,说明高盐突变激发凡纳滨对虾机体代谢活力。

EFFECTS OF HIGH-SALT ABRUPT ON GROWTH AND RELATED ENZYME ACTIVITIES IN LITOPENAEUS VANNAMEI

To investigate the effect of abrupt high-salinity change on growth, survival rate and enzyme activity of Litopenaeus vannamei in a 28-day experiment in which salinity changed abruptly from 30 (the control) to 35, 40, 45, 50, 55, and 60 in the first 12h. The survival rate, relative weight gain, and growth rate were determined every 7 days, and the acvtivities of Na⁺/K⁺-ATPase, T-ATPase, alkaline phosphatase (AKP), acidic phosphatase (ACP), and superoxide dismutase (SOD) were detected at the end of experiment. The results show that the high-salinity abrupt change inhibited the survival and relative weight gain of the shrimp significantly. The relative weight gain was reduced gradually with the increase of salinity, which was only 15.53% in 60 salinity group of the control. After the salinity changed abruptly to 50, the survival rate was significantly reduced. On the other hand, with the sudden increase of salinity, the activities of Na⁺/K⁺-ATPase and ACP were significantly (P<0.05) affected, Na⁺/K⁺-ATPase reached the highest at the salinity of 60, and the ACP showed a single-peak trend. However, the activities of T-ATPase, SOD, and AKP were not significantly affected (P>0.05). Therefore, the greater the range of the change, the lower of the survival rate and growth rate; and the activities of Na⁺/K⁺-ATPase, ACP, and osmotic regulation capacity increased. An abrupt salinity change could stimulate the metabolic activity of L. vannamei.