Silver nanoparticles (AgNPs) have garnered significant global attention from researchers due to their unique physicochemical properties and wide-ranging applications in industry and medicine. However, their release into aquatic ecosystems has raised concerns regarding potential ecotoxicological consequences. The present study investigated the effects of polyvinyl pyrrolidone-coated silver nanoparticles on Labeo rohita fingerlings, focusing on behavioural reactions, genotoxic effects, histological changes and bioaccumulation. L. rohita fingerlings were exposed to polyvinyl pyrrolidone-coated silver nanoparticles with sizes ranging from 18 to 29nm for 7days at concentrations of 100, 200, 400 and 800 ug/l. The nanoparticle zeta potential was found to be extremely negative, measuring - 55.5mV for 18nm and - 31.4mV for 29nm. Behavioural abnormalities, including respiratory distress, reduced responsiveness and erratic swimming, were observed in exposed groups compared to controls, with severity increasing with higher nanoparticle concentrations. Genotoxicity assessment revealed significantly higher DNA damage in kidney cells compared to gill cells. Histological examination of gill tissues showed clogging in primary and secondary lamellae, along with distorted anatomy, necrosis and vacuolar atrophy in peripheral tubules of the kidneys. The kidneys exhibited greater nanoparticle accumulation than the gills with prolonged exposure. Moreover, 18nm AgNPs induced more pronounced DNA damage and histological alterations in the kidney and gill tissues compared to 29nm nanoparticles. This study elucidates the critical role of monitoring AgNPs in aquatic systems, providing essential data on their behaviour and environmental impacts. The findings highlight the need for improved detection techniques and effective management of AgNP contamination. Future research should focus on developing more sensitive analytical methods, understanding long-term ecological effects and exploring innovative remediation strategies.
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