3种常见农药对中华鳖稚鳖的急性致毒效应研究

Acute Toxicity of Three Common Pesticides to Juveniles Trionyx sinensis (Wiegmann)

以5～7日龄的中华鳖稚鳖为试验动物,采用静水停食实验法,在水温(27.4±1.3)℃条件下,开展了乐果、三唑磷、氟虫腈对中华鳖稚鳖的急性毒性试验。结果表明,3种农药对中华鳖稚鳖均呈现以蓄积为主导的急性毒发效应,乐果对中华鳖稚鳖的急性致毒高峰期略滞后于三唑磷和氟虫腈;3种农药毒性强度大小依次为三唑磷、氟虫腈、乐果,其对中华鳖稚鳖96 h的半致死质量浓度分别为0.28μg/L、0.28 mg/L和124.4 mg/L;所构建的中华鳖稚鳖累计死亡概率与质量浓度和实验时间间数学模型和半致死时间—质量浓度回归方程可作为侦查和分析农药排放时间和致中华鳖稚鳖大量死亡时间的重要计算工具。

Acute toxicity of dimethoate,triazophos and fipronil on the（5-7）-day-old Trionyx sinensis juveniles without feeding were studied in the standing water at 27.4±1.3 ℃.The result indicates that accumulative character was found at the acute toxicity of three pesticides on Trionyx sinensis juvenile.And the acute toxicity time for the peak of dimethoate appears after that of triazophos,fipronil.The degree of the toxicity of three pesticides to Trionyx sinensis juvenile is in the order of triazophos,fipronil,dimethoate.And the median lethal concentrations（LC50） of 96 hours to the juvenile are 0.28 μg/L,0.28 mg/L,124.4 mg/L.The mathematical model and regression equation,which building in the death cumalative probability,the concenteation of three pesticides,the exoerimental time of Trionyx sinensis juvenile and between the median lethal time of the acute toxicity to the concenteation of three pesticides,are important basis for detecting and analysising of the time when three pesticides-induced emission and a large number of Trionyx sinensis juvenile died.