Ecological risks under combined pollution: Toxicological effects of clothianidin and microplastics on Penaeus vannamei

In real-world conditions, multiple pollutants coexist, making it insufficient to study a single pollutant's effects. Clothianidin, a widely present neonicotinoid insecticide, poses significant ecological risks due to its unique mechanism of action. Similarly, microplastics, another prevalent pollutant, have notable ecological impacts. This study aims to assess the ecotoxicological effects of clothianidin and microplastics on P. vannamei over 28 days, both individually and in combination. The study found that combined exposure significantly inhibited the shrimp's weight gain rate and hepatosomatic index, and significant changes were observed in the shrimp's immune defense, signal transmission, and energy metabolism. Key findings include changes in levels of hemocyanin, respiratory burst, nitric oxide, and phenol oxidase, as well as disturbances in enzyme activities of Lactate dehydrogenase, NADPH-dependent isocitrate dehydrogenase, and Succinate dehydrogenase. Additionally, fluctuations in levels of acetylcholine, dopamine, and acetylcholinesterase confirmed disruptions in neural signaling. Transcriptomic analysis further revealed the profound impact of these pollutants on gene expression and metabolic processes in the hepatopancreas and nervous system. This comprehensive assessment highlights the potential impact on shrimp growth and emphasizes the ecological risks of clothianidin and microplastics, providing insights for future risk assessments and the identification of biomarkers.