EVALUATING PESTICIDE-INDUCED TOXICITY IN CYPRINUS CARPIO: CYHALOTHRIN AS A CASE STUDY

The widespread agricultural application of synthetic pyrethroids has created environmental issues because they harm aquatic organisms that are not the target of treatment. This research examines the sublethal toxicity of lambda-cyhalothrin (LCH) on Cyprinus carpio's physiological, biochemical, and reproductive functions by subjecting the fish to controlled LCH exposure for 20 days. The 96-hour LC₅₀ value for LCH was established at 1.6 µg/L, while sublethal doses of LCH caused fish to become progressively hyperactive and produce mucus, and become lethargic. The biochemical analysis revealed protein content reductions of all variants, including structural and soluble proteins, while showing study concentrations enhanced protease activity with rising free amino acid levels, which indicated proteolysis along with metabolic disorder. Oxidative stress developed due to the significant reduction of antioxidant enzymes (CAT, SOD, GPx, GST) and accompanying MDA level increase. ATPase activity declined along with tissue ion concentrations because osmoregulatory paths and energy-dependent transport pathways lost their functionality. The fish showed reproductive problems through decreased gonado-somatic index and hormonal levels (testosterone, estradiol, 11-ketotestosterone) and gonad tissue degeneration. The blood tests showed reduced RBC numbers and decreased hemoglobin and PCV levels, and increased WBC counts, which indicated both anemic and immunological reactions. The research shows that C. carpio suffers multi-organ dysfunction when exposed to any amount of LCH below lethal levels, which creates significant ecological threats. According to this research, scientists need to tighten regulations regarding pesticide application while emphasizing how C. carpio functions as an excellent indicator for freshwater toxicology investigations.