低盐高碱度条件下氨氮对南美白对虾幼虾的急性毒性试验

Acute toxicity test of ammonia nitrogen to Litopenaeus annamei juveniles under low salinity and high alkalinity

在低盐高碱度(盐度5、总碱度250 mg/L)条件下,采用静水试验法研究氨氮对平均全长为(1.12±0.45)cm的南美白对虾幼虾的急性毒性。结果表明:在低盐高碱度条件下,氨氮对南美白对虾幼虾的24、48、72、96 h半致死质量浓度分别为1001.17、63.41、47.98、28.30 mg/L,得出氨氮和分子氨对南美白对虾幼虾的安全质量浓度分别为2.83、0.22 mg/L。氨氮对南美白对虾具有较强的毒性,并提出降低氨氮含量的措施。

Under static water conditions with low salt and high alkalinity(salinity 5,total alkalinity 250 mg/L),the acute toxicity test was conducted to examine the effect of ammonia nitrogen on Litopenaeus annamei juveniles with body length of(1.12±0.45)cm.Results showed that median lethal concentrations(LC_(50))of ammonia nitrogen were 1001.17,63.41,47.98,28.30 mg/L at the time point of 24,48,72,96 h respectively under low salt and high alkalinity conditions,so that its safe concentrations of total ammonia nitrogen and ionic ammonia nitrogen for Litopenaeus annamei juveniles were 2.83 mg/L and 0.22 mg/L,respectively.Ammonia nitrogen is highly toxic to Litopenaeus annamei,and measures to reduce the content of ammonia nitrogen have been proposed.