敌百虫对异育银鲫(Carassais auratus gibebio)毒性及其影响因素的研究

Toxicity of Trichlorfon Against Carassais auratus gibebio and Its Impacting Factors

采用静水法生物测试探讨了敌百虫对不同生长时期异育银鲫毒性及其毒性影响因素，为敌百虫在水产养殖中合理应用提供科学依据。根据试验期间死亡鱼数及死亡时间，用直线内插法计算各时间点的半致死浓度Lc如并根据死亡鱼数研究pH值和温度对敌百虫毒性的影响。结果表明：敌百虫对异育银鲫仔鱼（1．0g±0．3g）48、72、96h的LC50分别为121．19、90．22、59．78mg·L^-1，安全浓度为5．98mg·L^-1；对异育银鲫鱼种（23．2g±3．6g）48h的LC50为411．65mg·L^-1。当敌百虫的浓度在安全浓度范围内，环境pH值为6-8、水温低于26℃时，对鱼体毒副作用较小；随着pH值增大，水温升高，敌百虫对鱼体毒性增强，但环境pH值小于6，敌百虫对试验鱼无明显影响。

In this experiment, toxicity of trichlorfon and its impacting factors against Carassais auratus gibebio were studied. U- sing the method of linearinterpolation, acute toxicity test of trichlorfon to Carassais auratus gibebio was established in static water with different times and its impacting factors of trichlorfon toxicity was determined with mortality of Carassais auratus gibebio. The results showed the 48 h, 72 h and 96 h LCs0 （ median lethal concentration ） values for trichlorfon against fingerling of Carassais auratus gibebio（ 1.0 g± 0.3 g BW） were found to be 121.19,90.22,59.78 mg · L^-1, respectively, and deriving the safety concentration （ SC ） was 5.98 mg · L^ - 1. The LCs0 value of larval development of Carassais auratus gibebio （ 23.2 g ± 3.6 g, BW）for 48 h was 411.65 mg · L^-1. The toxicity of trichlorfon was stronger with enhancement of either water pH value or temperature and showed no effects on the fishes when the pH was below 6. In conclusion, trichlorfon had a low toxicity against the studied fish when trichlorfon concentration was in the safety range and at pH at 6-8 ,with temperature below 26 ℃.