氨氮对锈斑蟳早期幼体的急性毒性

在pH 8.5、水温(28.5±0.5)℃、盐度30条件下,用500 ml烧杯设置10、20、40、801、60 mg/L5个氨氮(总氮)质量浓度梯度和1个对照组(天然海水),研究氨氮对锈斑蟳早期幼体(Z1)急性毒性试验。结果表明,氨氮暴露12 h,40 mg/L以下质量浓度组毒性作用不显著,但80 mg/L以上质量浓度组与对照组差异显著(P<0.05);氨氮暴露24 h,20 mg/L以下质量浓度组毒性作用不显著,但40 mg/L以上质量浓度组与对照组有显著差异(P<0.05);氨氮暴露36～96 h,0、10 mg/L组间差异不显著,但20 mg/L以上质量浓度组与对照组有显著差异(P<0.05)。12、24、36、48、60、72 h氨氮暴露的半致死质量浓度分别为85.566、36.171、22.880、12.485、8.299、4.313 mg/L。锈斑蟳早期幼体培育的安全质量浓度为0.431 mg/L。

Acute Toxicity of Ammonia-N to Early Larval Swimming Crab Charybdis feriatus

The effects of ammonia(total ammonia nitrogen,0 mg/L,10 mg/L,20 mg/L,40 mg/L,80 mg/L,and 160 mg/L) on survival of swimming crab Charybdis feriatus zoea held in a 500 ml beaker were studied under the condition of pH 8.5,temperature of(28.5±0.5) ℃ and salinity of 30.The results showed that there was significantly difference in the survival in the zoea exposed to ammonia over 80 mg/L in 12 h compared with that in the control group(P<0.05).The survival rate of the zoea exposed to ammonia over 40 mg/L in 24 h were found significantly different(P<0.05) from that in the control group.The survival rate of the zoea exposed to ammonia over 20 mg/L in 36～96 h were significantly different(P<0.05) from the control group.The zoea had LC50 ammonia-N values(mg/L) of 85.566 mg/L for 12 h,36.171 mg/L for 24 h,22.880 mg/L for 36 h,12.485 mg/L for 48 h,8.299 mg/L for 60 h,and 4.313 mg/L for 72 h,with ammonia-N safe level of 0.431 mg/L.