Bisphenol S toxicity in zebrafish: Endocrine, neurobehavioural, and metabolic disruptions.

Bisphenol S (BPS), increasingly used as a substitute for Bisphenol A, has raised toxicological concern due to its environmental persistence and widespread exposure. Zebrafish (Danio rerio) provides a valuable model for assessing BPS toxicity because of conserved endocrine and neural pathways, rapid development, and well-established behavioural assays. This review synthesizes current evidence on the effects of BPS exposure in zebrafish. Available studies indicate that BPS is associated with alterations in multiple endocrine axes, including the hypothalamic-pituitary-gonadal, thyroid, and interrenal axes, with consequences for reproduction, thyroid hormone signaling, and stress regulation. Neurobehavioural alterations are frequently reported and are linked to oxidative stress, apoptosis, neurotransmitter imbalance, and isotocinergic or vasotocinergic dysregulation. Additional evidence associates BPS exposure with metabolic, cardiovascular, and immune alterations, including hepatic lipid accumulation, glucose dysregulation, vascular dysfunction, impaired myelopoiesis, inflammatory signaling, and gut microbial imbalance. Finally, this review highlights key knowledge gaps for future research.