不同盐度条件下氨氮对斑节对虾的毒性试验

Toxicity of Ammonia-N to Penaeus monodon under the Different Salinities

在5个盐度梯度(5,10,15,20,25)条件下分别设置不同氨氮浓度进行氨氮对斑节对虾(P.monodon)的急性毒性试验,计算斑节对虾的半致死浓度(LC50)和安全浓度(SC)。结果表明,盐度为25条件下,24h、48h、72h、96h的LC50分别为69.3mg/L、58.0mg/L、47.6mg/L和44.3mg/L;盐度为20条件下,分别为56.2mg/L、48.5mg/L、37.6mg/L和32.6mg/L;盐度为15的条件下,分别为39.6mg/L、30.5mg/L、26.2mg/L和21.6mg/L;盐度为10条件下,分别为29.9mg/L、27.8mg/L、22.1mg/L和20.7mg/L;盐度为5条件下,分别为19.5mg/L、14.3mg/L、13.9mg/L和12.5mg/L。而在盐度为25、20、15、10和5的条件下,氨氮的安全浓度分别为4.4mg/L、3.2mg/L、2.2mg/L、2.1mg/L和1.3mg/L。这说明盐度对氨氮的毒性有较大的影响,盐度越低,氨氮的安全浓度越小。

A conventional toxicity experiment was conducted to study the effect of ammonia nitrogen on the toxicity and disease resistance of P. monodon under different salinities of 25.0,20.0,15.0, 10.0 and 5.0 respectively. The results showed that the salinity had a significant influence on the toxicity of ammonia nitrogen to P. monodon. Under the salinity of 25.0, LC50 of 24h,48h,72h and 96h were 69.3mg/L; 58.0mg/L; 7.6mg/L and 44.3mg/L respectively;Under the salinity of 20, LC50 of 24h, 48h, 72h and 96h were 56.2mg/L, 48.5mg/L; 37.6mg/L and 32.6mg/L respectively;under the salinity of 15, LC50 of 24h, 48h, 72h and 96h were 29.9mg/L; 27.8mg/L respectively; 22. lmg/L and 20.7mg/L; under the salinity of 10, LC50 of 24h, 48h, 72h and 96h were 29.9mg/L;27.8mg/L;22. lmg/L and 20.7mg/L respectively ;under the salinity of 5, LC50 of 24h,48h,72h and 96h were 19.5mg/L; 14.3mg/L; 13.9mg/L and 12.5mg/L respectively;while under the salinity of 25.0,20.0,15.0,10.0 and 5, SCof 24h,48h,72h and 96h were 4.4mg/L; 3.2mg/L ; 2.2mg/L ; 2. lmg/L and 1.3mg/L respectively,therefore,under different salinity, SC Of P. rnonodon to ammonia nitrogen sequenced was 25〉 20〉 15 〉10〉 5, and the higher of ammonia nitrogen, the weaker of disease resistance of P. monodon, and the lower of salinity,the heavier of toxicity of ammonia nitrogen.