亚硝酸盐氮对日本囊对虾幼虾的急性毒性研究

Study on acute toxicity of nitrite to juvenile shrimp Marsupenaeus japonicus

在水温(28±0.2)℃、盐度29.8±0.2、pH8.0±0.2和溶氧6.0mg/L的条件下,将体长(49.28±4.79)mm日本囊对虾(Marsupenaeus japonicus)幼虾放在盛水20L的100L白桶中,用NaNO2(分析纯)溶于新鲜海水配制成2000mg/L的母液,使试验组水中亚硝酸盐氮(NO2^--N)质量浓度为151.36、239.88、380.19、602.56、954.99mg/L,采用静水毒性试验法研究了亚硝酸盐氮对日本囊对虾幼虾的急性毒性。结果显示,NO2^--N毒性效应与质量浓度和胁迫时间呈正相关。在同一时间下日本囊对虾的死亡率随着NO2^--N质量浓度的升高而增加;在同一质量浓度下对虾的死亡率随着时间的延长而升高。NO2^--N对日本囊对虾24、48、72、96h的半致死质量浓度(LC50)分别为1806.100、970.939、780.050、427.391mg/L,安全质量浓度为42.739mg/L。NO2^--N质量浓度为151.36、239.88、380.19、602.56、954.99mg/L的半致死时间(LT50)分别是120.008、111.954、94.207、78.810、60.102h。试验表明,日本囊对虾养殖水体中NO-2-N质量浓度应控制42.739mg/L以下。

Under the conditions of water temperature (28±0.2)℃,salinity 29.8±0.2,pH 8.0±0.2 and dissolved oxygen 6.0 mg/L,juvenile shrimp Marsupenaeus japonicus with body length of (49.28±4.79) mm was put in a 100 L white bucket with 20 L of water.NaNO 2 (analytical pure) was dissolved in fresh seawater to prepare 2 000 mg/L mother liquor and make the concentration of nitrite (NO2^--N) in the water of the test group 151.36,239.88,380.19,602.56 and 954.99 mg/L.The acute toxicity of NO2^--N to juvenile shrimp Marsupenaeus japonicus was studied by hydrostatic toxicity test.The results showed that the NO2^--N toxicity was positively correlated with the concentration and stress period,the mortality rate of Marsupenaeus japonicus increased with the increase of NO2^--N concentration at the same time,and the mortality rate of shrimp increased with time at the same concentration.The lethal concentration (LC50 ) of NO2^--N to Marsupenaeus japonicus was 1 806.100 mg/L in 24 h,970.939 mg/L in 48 h,780.050 mg/L in 72 h and 427.391 mg/L in 96 h,with safe concentration of 42.739 mg/L.The lethal time (LT50 ) was 120.008 h at concentration of 151.36,111.954 h at 239.88,94.207 h at 380.19,78.810 h at 602.56,and 60.102 h at 954.99 mg/L.The test showed that the concentration of NO2^--N should be controlled below 42.739 mg/L in culture water of Marsupenaeus japonicus.