甲氨基阿维菌素苯甲酸盐对泥鳅的急性毒性

将泥鳅暴露于甲维盐进行急性毒性实验，依据概率单位法计量不同暴露时间甲维盐相应的半致死浓度以及安全浓度。结果表明，甲维盐对泥鳅的48 h-LC₅₀为14.137 mg·L^-1 ，96 h-LC₅₀为6.765 mg·L^-1。甲维盐浓度与泥鳅的死亡率呈现明显的剂量效应关系。随着暴露时间延长，半数致死浓度降低，安全浓度降低。采用组织学方法评估了不同浓度的甲维盐暴露下，泥鳅视网膜、皮肤、鳃的组织学结构变化。在20 mg·L^-1甲维盐急性暴露下，泥鳅皮肤出现脂褐质沉积、分泌细胞减少、神经丘细胞大量丢失。同时甲维盐能够造成视网膜变薄，视细胞的內节/外节丢失，引起视觉障碍。

Acute Toxicity of Emamectin Benzoate to Loach

Acute toxicity test of loach exposed toemamectin benzoate (EB) was carried out in this study. Using the probability unit methods, the half lethal concentration and safe concentration were calculated when loach exposed to different time. The results showed that the 48 h-LC₅₀ and 96 h-LC₅₀ of emamectin benzoate to loach was 14.137 mg·L^-1 and 6.765 mg·L^-1. Obvious dose-effect relationship was showed between salt concentration and loach mortality. With the exposure time increased, both half lethal concentration and safety concentration have decreased. Using histological methods, the histological structure of gill, retinal, skin changes were observed in the loach exposed to different concentrations of EB. The results also showed that 20 mg·L^-1 EB treatment group caused lipofuscin deposition, secretory cell reduced and nerve mast cells lost in skin. In addition, retinal cell layer has become thinner and inner segment/outer segment of the photoreceptor cells has lost, which caused visual impairment.