The dual toxicity of bisphenol A in Larimichthys polyactis: Inhibition of growth and impairment of gonadal development.

Bisphenol A (BPA) is a widely distributed endocrine-disrupting chemical (EDCs) in aquatic ecosystems. Larimichthys polyactis is an economically important fish species in China's nearshore waters, characterized by unique sexual differentiation patterns. However, research on the effects of BPA exposure on this species remains limited. This study used 30 days post-hatching (dph) L. polyactis to assess the impact of BPA exposure at three concentrations: 1 μg·L-1, 50 μg·L-1, and 500 μg·L-1, with a control group (WT), over a 60-day immersion period. Survival rate, growth, gonadosomatic index (GSI), and histological changes were examined to evaluate BPA's effects on growth, gonad differentiation, and development. Recovery was also assessed for 60 days post-exposure. Results showed that L. polyactis exhibited a high tolerance threshold to BPA, with short-term exposure significantly affecting the GSI, gonad structure, and reproductive cell density. Long-term exposure caused gonadal abnormalities and growth retardation. BPA's effects were clearly dose-dependent, time-dependent, and exhibited gender-specific differences. Despite partial recovery in growth and gonadal structure post-exposure, changes followed a non-monotonic dose-response, indicating that BPA disrupts multiple physiological processes in L. polyactis. Furthermore, long-term low-dose exposure posed a greater threat than acute high-dose exposure. These findings provide a theoretical basis for formulating effective water pollution control strategies and preserving marine biodiversity and fisheries.