Influence of prolonged exposure to acetamiprid on the toxicology of the decapod crustacean Pacific white shrimp Penaeus vannamei

Neonicotinoid insecticides have raised increasing concerns due to their toxic effects on aquatic invertebrates, potentially contributing to population declines and aquatic food web disruption. This study investigated the chronic toxicity of the first-generation neonicotinoid acetamiprid on Penaeus vannamei using physiological, biochemical, and transcriptomic approaches. After 28 days of exposure, significant reductions in survival rate, growth performance, and hepatosomatic index were observed, with a calculated 96 h LC₅₀ of 60.81 μg/L. Acetamiprid exposure led to oxidative stress, as indicated by altered antioxidant enzyme activities and the downregulation of related genes. Genes involved in circadian rhythm, thyroid hormone, and neurotrophin signaling pathways were significantly suppressed. Additionally, Phase I detoxification genes (e.g., CYP450 family) were upregulated, while Phase II genes (e.g., GSTs) were downregulated, suggesting a disrupted detoxification mechanism. These findings suggest that P. vannamei is sensitive to acetamiprid, and prolonged exposure may impair growth and physiological homeostasis through oxidative and neuroendocrine disturbances. This study provides insights into the potential ecological risks of acetamiprid in aquaculture environments.