This study assessed the hematological, enzymatic and osmoregulatory responses of silver catfish (Rhamdia quelen) exposed to sublethal concentrations (1.125 and 3.750 µg/L) of a commercial thiamethoxam-containing insecticide used on rice crops. Groups of 6 fish per tank (in triplicate, n = 3, total 54 fish) were exposed for up to 96 h to different concentrations of the compound. After this period, fish were placed in clean water for 48 h. Two fish from each tank (6 per treatment) that had been exposed to the insecticide for 24 h were anesthetized with eugenol and blood was collected to evaluate hematological and biochemical parameters. Blood, liver and muscle were collected for determination of metabolic parameters, plasma cortisol, Cl^-, Na⁺ and K⁺ levels and H⁺-ATPase and Na⁺/K⁺-ATPase activity in the gill. H⁺-ATPase activity was higher in fish exposed to 1.125 µg/L insecticide at 24 h compared to control (0.0 µg/L). Differences in cortisol levels were evidenced throughout the experimental period. These results indicated that exposure to the insecticide changed the hematological, biochemical and metabolic profile of the animals, suggesting concern about environmental safety. Therefore, we discourage the use of this pesticide in areas that come into contact with water bodies inhabited by fish.

这项研究评估了银let鱼（Rhamdia quelen）暴露于致死浓度（1.125和3.750 µg / L）的用于水稻作物的商业性含噻虫嗪杀虫剂的血液学，酶促和渗透调节反应。每罐6组鱼（一式三份，n = 3，总共54条鱼）暴露于不同浓度的化合物下长达96小时。在此期间之后，将鱼置于清洁水中48小时。用丁子香酚麻醉每个储罐中的两条鱼（每次处理6条），暴露24小时，用丁香酚麻醉，收集血液以评估血液学和生化指标。血液，肝脏和肌肉收集用于测定代谢参数，血浆皮质醇，氯^- ，钠⁺和Klevels中的⁺水平和H ⁺ -ATPase和Na ⁺ / K ⁺ -ATPase活性。与对照组（0.0 µg / L）相比，在24 h暴露于1.125 µg / L杀虫剂的鱼中H ⁺ -ATPase活性更高。在整个实验期间，皮质醇水平存在差异。这些结果表明，接触杀虫剂改变了动物的血液学，生化和代谢特征，表明对环境安全性的关注。因此，我们不鼓励在与鱼类居住的水体接触的区域使用这种农药。