Abstract
In this study, the induced behavioral changes and neuropathology of prolonged exposure to high doses of Zinc nanoparticles (Zn-NPs) in two species of tilapia, T. nilotica and T. zilli. was investigated. Fish that were treated with 2000 mu g Zn-NPs/L showed severe degenerative changes and vacuolation in the neuropil, particularly of the optic tectum, with congestion of the blood vessels of both the cerebral cortex and the meninx primitive. Loss of the Purkinje cell layer of the cerebellum was noticed as well. Fish showed behavioral changes that included loss of equilibrium, slower movement and swimming sideways. No significant differences (P < 0.05) were observed between T. nilotica and T. zilli in behavioral or pathological changes. The results highlighted the Zn-NPs neurotoxicity and its accompanied neuropathology and related behavioral changes in fish. More caution is needed during the usage of Zn-NPs to avoid possible deleterious impacts on human and animal health.