氨氮对红星梭子蟹早期幼体的急性毒性

Acute Toxicity of Ammonia-N to Early Larvae of Red Spotted Swimming Crab Portunus sanguinolentus

在盐度30、pH 8.5、温度28.8～29.8℃、投喂扁藻和轮虫的条件下,设置10、20、40、80、160mg/L共5个氨氮梯度和1个对照组(天然海水),进行了氨氮对红星梭子蟹早期幼体(第Ⅰ期溞状幼体,Z1)的急性毒性试验。结果发现,氨氮暴露12～72h,红星梭子蟹早期幼体活力组间差异显著(P<0.05),当氨氮继续暴露至84～96h,早期幼体活力组间差异不显著(P>0.05);氨氮暴露12～96h,红星梭子蟹早期幼体存活率组间差异显著(P<0.05),但对照组与10mg/L试验组差异不显著(P>0.05);红星梭子蟹早期幼体的氨氮暴露12、24、36h时的半致死质量浓度分别为80.94、27.96、14.43mg/L,红星梭子蟹早期幼体暴露36h的氨氮安全质量浓度为1.44mg/L。

Acute toxicity of ammonia-N to early zoea（Z1） was studied in red spotted swimming crab Portunus sanguionlentus fed on rotifer Brachionus plicatilis and alga Platymonas subcordiformis and exposed to ammonia-N concentrations of 0 mg/L（as control）,10 mg/L,20 mg/L,40 mg/L,80 mg/L,and 160 mg/L at a salinity of 30,pH 8.5,and temperature of 28.8～29.8 ℃.The results showed that the early zoea exposed to ammonia-N for 12～72 h had significantly different viability（P0.05）.The survival rate was significantly different in the zoea exposed to ammonia-N for 12～96 h（P0.05） between the control group and group of 10 mg/L.The early zoeal LC50 for ammonia-N were 80.9 4 mg/L for 12 h,27.96 mg/L for 24 h and 14.43 mg/L for 36 h.The early zoea are highly sensitive to ammonia-N with safe level of 1.44 mg/L.