Triclosan and its metabolites are detected in a diverse aquatic environment and are major concerns for various aquatic organisms. The present study investigated the impact of acute and sub-lethal exposure of triclosan on behaviour, activities of acetylcholinesterase and selected antioxidant enzymes, haematological and serum gas-electrolyte parameters of Pangasianodon hypophthalmus. The 96 h LC₅₀ of triclosan for P. hypophthalmus was estimated as 1458 μg L⁻¹. Further, sub-lethal triclosan exposure to 1/15th (97 μg L^-1), 1/10th (145 μg L^-1) and 1/5th (291 μg L^-1) of 96 h LC₅₀ concentration for a period of 45 days lead to decrease in total erythrocyte count, haemoglobin content and packed cell volume of blood while total leukocyte count increased significantly (p < 0.05) as compared to control. A concentration-dependent increase in the serum chloride and decrease in partial pressure of oxygen in blood serum was noted on 45th day. An increased activity of catalase and superoxide dismutase in gill and liver tissues and inhibition of acetylcholinesterase activity in brain was observed on 15th, 30th and 45th day of exposure which was dependent on both - concentration of triclosan and duration of exposure. A significant high activity of glutathione-S-transferase in gill and liver tissue was observed in triclosan exposed groups in comparison to control during the experimental period. The study shows that long-term sub-lethal exposure of triclosan to fish can lead to several physiological alterations such as enzymatic scavenging of oxygen radicals and the normal neurological functions mediated by the enzyme acetylcholinesterase. With increasing anthropogenic activity, the study provides a convincing evidence for the necessity of a regulated use and safer disposal of triclosan to the environment.

在多种水生环境中检测到三氯生及其代谢产物，这是各种水生生物的主要关注点。本研究调查了三氯生的急性和亚致死性暴露对行为，乙酰胆碱酯酶和选定的抗氧化剂酶的活性，下眼球泛虾的血液学和血清气体电解质参数的影响。三氯生对垂体假单胞菌的96 h LC ₅₀估计为1458μgL ^-1。此外，亚致死三氯生暴露于1/15日（97微克大号^-1），1/10（145微克大号^-1）和1 /第五（291微克大号^-1 96小时LC的）₅₀与对照组相比，浓度在45天的时间内可导致总红细胞计数，血红蛋白含量和血液堆积细胞体积减少，而总白细胞计数则显着增加（p <0.05）。在第45天观察到血清氯化物浓度依赖性增加和血清氧分压降低。在接触的第15、30和45天观察到ill和肝组织中过氧化氢酶和超氧化物歧化酶的活性增加，并且大脑中的乙酰胆碱酯酶活性受到抑制，这取决于三氯生的浓度和接触时间。在实验期间，与对照相比，在暴露于三氯生的组中，g和肝脏组织中的谷胱甘肽-S-转移酶具有显着的高活性。研究表明，三氯生长期暴露于鱼类中可能导致几种生理变化，例如酶清除氧自由基和乙酰胆碱酯酶介导的正常神经功能。随着人为活动的增加，该研究提供了令人信服的证据，证明三氯生必须规范使用和更安全地排放到环境中。