Analysis of the Biochemical and Histopathological Impact of Polystyrene Microplastic on Channa Punctata (Bloch, 1793) Fish.

Background: Polystyrene microplastics (PS-MS) are emerging contaminants in aquatic ecosystems and a serious threat to aquatic organisms. The toxicological effects of PS-MS on Channa punctata were evaluated by biochemical, histopathological, and physiological parameters. Methods: Four groups (Control, (1 mg/l) Dose 1, (5 mg/l Dose 2, (10 mg/l) Dose 3) of fish were exposed to PS-MS for 28 days. Fulton’s Condition Factor (K), Hepatosomatic Index (HSI), and Kidney Somatic Index (KSI) were measured as biometric indices. Serum biochemical markers of liver (ALT, AST) and kidney (Creatinine, BUN) function were measured. Structural abnormalities in liver and kidney tissues were observed by histopathological analysis. Results: Significant dose-dependent reductions in biometric indices were observed, consistent with physiological stress. Dose-dependent increases in liver and kidney function markers confirmed hepatic and renal toxicity. Liver tissues and kidney tissues showed severe vacuolization, necrosis sinusoidal congestion in liver tissues and tubular degeneration, glomerular atrophy, and necrosis in kidney tissues, particularly at higher doses. Conclusion: Channa punctata exposed to PS-MS experiences significant dose-dependent physiological and cellular disruptions. The findings underscore the need for immediate action to mitigate microplastic pollution and protect aquatic biodiversity.