Histopathological Effects of Zinc Oxide (ZnO) Nanoparticles on Tissues of Mediterranean Mussel (Mytilus galloprovincialis Lamarck, 1819)

Abstract Nanoparticles have gained increased importance due to their use in various fields, their unique properties, and their high reactivity. Zinc oxide (ZnO) nanoparticles, which are used in different applications, are known to have adverse effects, particularly on aquatic ecosystems. Mytilus galloprovincialis (Black mussel or Mediterranean mussel) is a species that is distributed in our country's seas and has economic importance as a food source for humans. Additionally, M. galloprovincialis, being a bioindicator species, accumulates various pollutants in its body through filter feeding.In this study, mussels were exposed to different concentrations of ZnO nanoparticles (0; 0.01; 0.1and 1 mg/l) for a duration of 96 hours, and the subsequent toxic effects were evaluated in terms of histopathological findings. In the histological examinations of mussels exposed to ZnO nanoparticles, lipofuscin aggregates, dilated central veins, lamellar fusion, hemocyte infiltrations in the gills, hemocyte infiltrations, and hypertrophy were observed in the mantle, as well as lipofuscin aggregates, hemocyte infiltrations, and hypertrophy in the digestive gland.In conclusion, it was found that ZnO nanoparticles have negative histopathological effects on Mediterranean mussels. These findings suggest the presence of toxicity and tissue damage. Considering the ecological importance of M. galloprovincialis as a filter-feeding organism and its economic value as a food source, it is crucial to be aware of the potential adverse effects of ZnO nanoparticles. Further studies are needed to investigate the long-term effects and ecological implications of ZnO nanoparticle