Lambda-cyhalothrin is a synthetic pyrethroid that mimics the structure and insecticidal properties of pyrethrin, a natural insecticide derived from chrysanthemums. In fish, it disrupts the nervous system, causing motor paralysis and several other alterations associated with varying levels of mortality. This study aimed to evaluate osmoregulatory responses and histological changes in the gills of Oreochromis niloticus chronically exposed to a sublethal dosage (0.86 μg/L) of lambda-cyhalothrin. The mean serum values for Na²⁺, K⁺, Cl⁻, Ca²⁺, pH, lactate, H⁺, HCO^3, and glucose along to degree of tissue change (DTC) at 24, 96, 168, and 240 h post-exposure (hpe) were evaluated. Lambda-cyhalothrin affected the neuronal motor function at 24 hpe, followed by the increase of the K⁺, Ca²⁺, H⁺, and glucose levels in the exposed group, compared to the control group. Lactate and H⁺ levels in the exposed group were higher than those in the control group at 168 and 240 hpe respectively. HCO³, and Cl- levels increased at 240 hpe, although there was no change in the pH values. DTC was higher in treated fish than in control fish, but there were no significant differences among time-exposure. The changes detected ranged from hyperemia of the branchial vasculature, eosinophilic granulocytic cell infiltration, mucous cell hyperplasia, and partial fusion of secondary lamellae at 24 hpe to vascular aneurysm formation, and necrosis of the lamellar epithelium at 240 hpe. Thus, a sublethal dosage of lambda-cyhalothrin in the long-term is toxic for Nile tilapia, characterized by hypokalemia, hypercalcemia, hyperglycemia, and respiratory alkalosis, followed by time-dependent histological changes.

Lambda-cyhalothrin是一种合成的拟除虫菊酯，模仿拟除虫菊酯（一种衍生自菊花的天然杀虫剂）的结构和杀虫特性。在鱼类中，它破坏神经系统，导致运动麻痹和与死亡率不同有关的其他几种改变。这项研究旨在评估长期暴露于半致死剂量（0.86μg/ L）的氟氯氰菊酯的尼罗罗非鱼chrom的渗透调节反应和组织学变化。平均血清值的Na ²⁺，K ⁺，氯^- ，钙²⁺，pH值，乳酸盐，H ⁺，HCO ^3，沿至（DTC）24，96，168，组织变化的程度和240小时，葡萄糖曝光后（hpe）进行了评估。与对照组相比，λ-氟氯氰菊酯在24 hpe时会影响神经元的运动功能，随后K ⁺，Ca 2 ⁺，H ⁺和葡萄糖水平升高。暴露组的乳酸和H ⁺水平分别在168和240 hpe时高于对照组。240 hpe时HCO ³和Cl-含量增加，尽管pH值没有变化。处理后的鱼的DTC高于对照鱼，但时间接触之间无显着差异。检测到的变化范围包括分支血管充血，嗜酸性粒细胞浸润，粘液细胞增生，24 hpe继发性片状部分融合至血管瘤形成以及240 hpe的层状上皮坏死。因此，长期使用亚致死剂量的氟氯氰菊酯对尼罗罗非鱼具有毒性，其特征在于低钾血症，高钙血症，高血糖症和呼吸性碱中毒，随后是随时间变化的组织学变化。