Pendimethalin (PM) is a selective herbicide, widely present in aquatic environment. It causes detrimental effects in fishes, but little is known regarding its reproductive toxicity. The present study was carried out in Clarias batrachus exposed to sub lethal concentrations of PM for 30, 45 and 60 days. Male fish showed a significant increase in plasma 17β-estradiol (E2) however plasma E2 in females was not affected. Plasma testosterone levels were significantly decreased in both sexes. In male plasma vitellogenin (VTG) and gonadal aromatase activity was increased irrespective of herbicide concentration and exposure duration. In females concentration and time dependent reduction in plasma VTG but no significant change in the gonadal aromatase activity were observed. Results indicated that PM act as endocrine disruptor but act differentially in male and female fishes and plasma E2, T and VTG levels and aromatase activity can be considered as reliable biomarkers for PM toxicity in fishes.

二甲戊灵（PM）是一种选择性除草剂，广泛存在于水生环境中。它对鱼类造成有害影响，但对其生殖毒性知之甚少。本研究是在非洲胡Cl鱼中进行的暴露于亚致死浓度的PM中30、45和60天。雄鱼的血浆17β-雌二醇（E2）显着增加，而雌鱼的血浆E2则没有受到影响。男女的血浆睾丸激素水平均明显降低。在男性血浆中，卵黄蛋白原（VTG）和性腺芳香化酶的活性增加，而与除草剂的浓度和暴露时间无关。在雌性中血浆VTG的浓度和时间依赖性降低，但未观察到性腺芳香化酶活性的显着变化。结果表明，PM可作为内分泌干扰物，但在雄性和雌性鱼类中的作用却不同，血浆E2，T和VTG水平以及芳香化酶活性可被视为对鱼类PM毒性的可靠生物标记。