非离子氨和亚硝酸氮对虾虎鱼仔鱼的急性毒性及安全浓度评价

Acute Toxicity and Safety Assessment of Non-ion Ammonia and Nitrite on Larvae of Ctenogobius gymnauchen

目的检测非离子氨和亚硝酸氮对鱼类的生态毒性效应。方法在水温(25±1)℃、溶氧(6.07～6.77)mg/L、盐度30～31、pH8.0～8.2的条件下,采用半静水式生物毒性试验方法研究了非离子氨和亚硝酸氮对裸项栉虾虎鱼(Ctenogobius gymnauchen)仔鱼的急性毒性效应(非离子氨浓度梯度设置为0、0.413、0.735、1.309、2.329、4.147 mg/L,亚硝酸氮浓度梯度设置为0、3.0、4.14、5.713、7.884、10.88 g/L)。结果非离子氨和亚硝酸氮暴露后仔鱼出现呆滞、侧游、呼吸困难、体色变白、身体弯曲等中毒症状,且随着暴露浓度的升高与暴露时间的延长,死亡率逐渐增加,存在明显的剂量效应关系和时间效应关系;非离子氨和亚硝酸氮对裸项栉虾虎鱼仔鱼96 hLC50分别为9.1 mg/L和12.405 g/L,其安全浓度分别为0.91 mg/L和1.2405 g/L。结论裸项栉虾虎鱼对非离子氨和亚硝酸氮具有较强的耐受力,非离子氨对裸项栉虾虎鱼仔鱼的毒性显著大于亚硝酸氮。

Objective To explore the toxic effect of non-ion ammonia and nitrite on larvae of Ctenogobius gymnauchen.Methods The semi-static acute toxicity trial was carried out under the conditions of water temperature（25±1）℃,dissolved oxygen 6.07-6.77 mg/L,salinity 30 and pH 8.0-8.2.Results The toxicity symptoms of non-ion ammonia and nitrite on larvae of Ctenogobius gymnauchen included dull movement,loss of equilibrium,difficulty breathing,body whitening and bending were becoming obvious and the mortality was increasing with the exposure concenation increasing and exposure time prolonging.The 96hLC50 of non-ion ammonia and nitrite on larvae of Ctenogobius gymnauchen were 9.1 mg/L and 12.405 g/L respectively.The safe concenafion were 0.91 mg/L and 1.2405 g/L respectively.Conclusions Ctenogobius gymnauchen has extensive tolerance to non-ion ammonia and nitrite.The toxicity of non-ion ammonia on larvae of Ctenogobius gymnauchen is significantly more effective than nitrite.