Pesticide toxicity in Procambarus clarkii: Integrating oxidative stress, immune dysfunction, and gut microbiota...

Rice-shrimp integrated systems are ecologically sustainable but face increasing threats from pesticide use. In these systems, pesticides undergo multi-media migration and accumulate in sediments, creating chronic exposure regimes for the benthic crustacean Procambarus clarkii, a key non-target species. This review systematically examines the multi-level toxic effects of commonly used pesticides on P. clarkii, focusing on oxidative stress, immune suppression, digestive dysfunction, and gut microbiota disruption. At the molecular level, the core roles of key signaling pathways, including phosphoinositide 3-kinase/protein kinase B/mechanistic target of rapamycin (PI3K/AKT/mTOR), mitogen-activated protein kinase (MAPK), and nuclear factor kappa B (NF-κB), are elucidated in mediating abnormal autophagy, metabolic reprogramming, and immune gene expression dysregulation. Based on these findings, a cascade toxicity model is proposed that links molecular initiating events to individual physiological damage and potential population decline. Ecological risk assessment further indicates that chronic risks from pesticide residues in sediments significantly outweigh acute risks from water exposure. Finally, mechanism-driven sustainable management strategies are proposed, including multi-omics biomarker-based early warning systems, constructed wetland purification, and probiotic-functional feeds. This review not only deepens the mechanistic understanding of pesticide toxicity in aquatic invertebrates but also provides a theory-to-practice framework for the green transformation of rice-shrimp systems.