Effects of nano products on physiological reproduction of fish.

The rapid advancement of nanotechnology has driven a substantial expansion in the production and utilization of nanoproducts across diverse industries. However, the concomitant increase in nanoparticle entry into the water column has given rise to significant concerns, with mounting evidence indicating the potential for deleterious effects on the reproductive health of fish. This review assesses the effects of metal oxides, metals, polymers, and quantum dot nanoparticles on key aspects of fish reproductive physiology, including hormonal balance, gonadal development, gamete viability, and embryonic toxicity. A comprehensive analysis of the available literature suggests that nanoparticles disrupt sex hormone homeostasis by interfering with the hypothalamic-pituitary-gonadal (HPG) axis. Accumulation of nanoparticles in the gonads induces oxidative stress, resulting in structural and functional damage to the gonads. Furthermore, nanoparticle exposure exerts significant embryotoxic effects, manifested as elevated mortality rates, teratogenic abnormalities, and reduced hatchability. Mechanistic studies identify oxidative damage and dysregulation of developmental gene networks as primary contributors to these embryotoxic outcomes. The current evidence suggests that the increasing accumulation of nanoparticles in aquatic environments threatens the reproductive function of individual fish and the survival of fish populations in multiple ways. Further research is needed to elucidate the toxicity mechanisms of nanoparticles, transgenerational effects and the molecular drivers of reproductive dysfunction. Addressing these knowledge gaps is critical for mitigating risks to aquatic biodiversity and ensuring the long-term sustainability of fish populations in nanoparticle-contaminated ecosystems.