Exposure of crayfish (Procambarus clarkii) to pinoxaden disrupts hepatic transcriptome, gut microbiome, and redox homeostasis

With the widespread use of pesticides, pinoxaden has become a commonly used herbicide in rice-crayfish co-culture fields. However, the mechanism of toxicity to aquatic organisms is unclear. This study investigated the acute toxicity effects of pinoxaden on crayfish. Biochemical analysis revealed significant alterations in malondialdehyde content, as well as glutathione peroxidase, superoxide dismutase and catalase activities in hepatopancreas tissues following pinoxaden exposure. Histological examination revealed pinoxaden-induced impairment in the hepatopancreas and gut tissues of crayfish. Transcriptomic profiling detected genes with differential expression following pinoxaden treatment, significant enrichment of pathways including lysosome, antigen processing presentation, phagosome. Furthermore, pinoxaden exposure altered the abundance of bacterial families such as Actinobacteriota and Erysipelatoclostridium in the gut microbiota of exposed groups. This study provides important insights into the toxicity of pinoxaden to crayfish, offering practical guidance for the scientifically based and rational use of pesticides in rice-crayfish co-culture systems.