Fipronil is a current use pesticide, widely used in many crops, commonly adsorbed to sediments of aquatic environments. The purpose of this study was to evaluate the biomarker responses and fipronil distribution pattern in different matrixes (fish, sediment and water) after juveniles P. lineatus exposure at two environmental concentrations (5.5 and 82 μg kg^‐−1) of fipronil-spiked sediments. The levels of oxidized proteins (PO), lipid peroxidation (LPO), and enzymatic activity of superoxide dismutase (SOD), reduced glutathione content (GSH), antioxidant capacity against peroxyls (ACAP) and acetylcholinesterase (AChE) were evaluated in liver, gills and brain. Concentrations of fipronil and its metabolites (f. desulfinyl, f sulphpHide and f. sulfone) were quantified by GC-ECD. F. desulfinyl was the major metabolite found in all matrixes, followed by f. sulphide in sediments, while f. sulfone was mainly accumulated in fish. Fipronil promoted oxidative stress in P. lineatus, as evidenced by the increases in LPO and PO levels and the decrease brain AChE activity. Fish exposed at both concentrations showed significant decrease in antioxidant capacity. Alterations in the antioxidant defenses system was evidenced in all organs. These results suggest that the occurrence of fipronil in aquatic environments can generate oxidative stress at different levels in P. lineatus, showing that this species is highly sensitive to the deleterious effects of fipronil and metabolites.

氟虫腈是目前使用的农药，广泛用于许多作物，通常吸附在水生环境的沉积物中。本研究的目的是评估后少年生物标志物响应和在不同的矩阵（鱼，沉淀物和水）氟虫腈分布图案P.绦虫在两个环境浓度（5.5和82微克曝光公斤^{- -1}) 含有氟虫腈的沉积物。在肝脏、鳃中评估氧化蛋白 (PO)、脂质过氧化 (LPO) 和超氧化物歧化酶 (SOD) 的酶活性、谷胱甘肽含量 (GSH)、抗过氧化物 (ACAP) 和乙酰胆碱酯酶 (AChE) 的抗氧化能力和大脑。通过 GC-ECD 对氟虫腈及其代谢物（f. desulfinyl、fsulfpHide 和 f. 砜）的浓度进行定量。F. desulfinyl 是所有基质中发现的主要代谢物，其次是 f。沉积物中的硫化物，而 f．砜主要在鱼体内积累。氟虫腈促进P. lineatus 的氧化应激，正如 LPO 和 PO 水平的增加以及脑 AChE 活性的降低所证明的那样。暴露于两种浓度的鱼的抗氧化能力显着下降。在所有器官中都证明了抗氧化防御系统的改变。这些结果表明，氟虫腈的在水生环境发生可以在不同级别中产生的氧化应激P.绦虫，可见这物种是氟虫腈和代谢物的有害作用高度敏感。