Description:
Environmental accumulation of thiamethoxam has increasingly become a risk for the health of aquatic animals, especially crustacean species in the same phylum with the target pests. The lack of knowledge on the toxicity of thiamethoxam to crustaceans motivates our study to test the median lethal concentration (LC 50 ) of the most commonly seen aquatic crustacean, Litopenaeus vannamei exposed to thiamethoxam. Following an acute toxicity assay, a 28-d chronic toxicity experiment was conducted. Thiamethoxam induced oxidative stress and decreased growth performance in shrimp. In addition, thiamethoxam has led to a substantial imbalance of the micro-ecosystem in the intestine. The composition of intestinal flora changed significantly, and the balance of the interaction network was broken. The benign competitive interaction of many bacteria became unstable cooperative interaction. Transcriptomic analysis showed that the numbers of up- and down-regulations in differentially expressed genes (DEGs) increased in a dose-dependent manner. These DEGs were significantly enriched in the pathways related to detoxification, and the expression of most detoxification genes was up-regulated. DEGs related to detoxification were positively correlated with Shima and negatively correlated with Pseudoalteromonas . This study provides evidence for the first time on the toxic effects of thiamethoxam on the growth, biochemistry, intestinal flora and transcriptome in aquatic crustaceans