氨氮对斑节对虾的毒性及免疫指标的影响

采用生物毒性实验方法研究了氨氮对斑节对虾的急性毒性作用,结果表明:毒性效应与氨氮浓度和中毒时间呈正相关,在海水温度为30℃,pH为8,盐度为34.5条件下,氨氮对斑节对虾24 h、48 h、72 h、96 h的半致死浓度分别为52.63 mg/L、39.68 mg/L、31.65 mg/L、29.94 mg/L,安全浓度为2.99mg/L,对应的非离子氨分别为3.23 mg/L、2.43 mg/L、1.94 mg/L、1.84 mg/L,安全浓度为0.18 mg/L。并在浓度为29.94 mg/L氨氮胁迫下,对斑节对虾免疫指标的影响进行了研究。结果显示,在96 h内斑节对虾血清中免疫指标变化为:酚氧化酶(PO)的活力总体上呈下降趋势;超氧化物歧化酶(SOD)和过氧化物酶(POD)活力变化均是先升高,再下降;酸性磷酸酶(ACP)的活力变化为先升高,然后下降,再上升。单因素方差分析(ANOVA)表明,斑节对虾血清中的PO、SOD、POD、ACP活力8个取样时间点(0 h、4 h、8 h、12 h、24 h、48 h、72 h、96 h)内均有极显著性差异(P<0.01)。而对照组8个取样时间点的各酶活力均未达到显著差异(P>0.05)。本研究获得了氨氮对斑节对虾的急性毒性结果和在高氨氮胁迫下免疫因子的变化规律,发现高氨氮对斑节对虾免疫系统有重要影响,为斑节对虾养殖健康发展提供科学依据。

The toxicity of ammonia N on Penaeus monodon and immune parameters

The results of acute toxicity test of ammonia-N on Penaeus monodon carried out by biological toxicity test showed that effect of toxicity has a significant positive correlation with the ammonia-N maintained time and concentration.In the condition of seawater 30℃,pH=8,S=34.5,the half lethal concentration of ammonia-N were 52.63 mg/L,39.68 mg/L,31.65 mg/L and 29.94 mg/L,lasting for 24 h,48 h,72 h and 96 h respectively,and the safe concentration was 2.99 mg/L.In the same concentration,half lethal concentration of non-ionic ammonia were 3.23 mg/L,2.43 mg/L,1.94 mg/L,1.84 mg/L respectively and the safe concentration was 0.18 mg/L.The effect of ammonia-N level of 29.9 mg/L on immune parameters of Penaeus monodon showed the variation trend of different immune parameters :including activity of phenoloxidase(PO) decreasing in the whole of study,superoxide dismutase(SOD) and peroxidase(POD) activity in serum increasing at first after ammonia-N stimulated and then decreasing,acid phosphatase(ACP) activity increasing at first after ammonia-N stimulated,then decreasing and increasing at last within 96h.ANOVA indicated that the activities of PO,SOD,POD,ACP in eight sampling points(0 h,4 h,8 h,12 h,24 h,48 h,72 h,96 h) had significant difference(P< 0.01),while the control groups all had no significant difference(P> 0.05).Acute toxicity result,changes of different immune parameters in high ammonia-N stress and influence of high ammonia on the immune system obtained in this study provide a scientific basis for the healthy development of culture of Penaeus monodon.