Abamectin inhibits energy metabolism by disturbing tricarboxylic acid (TCA) cycle in red swamp crayfish (Procambarus clarkii)

Since current culture model of red swamp crayfish ( Procambarus clarkii ) is mainly rice-shrimp co-culture model, the use of pesticide is inevitable. As a broad-spectrum pesticide, abamectin is widely used in aquaculture. Thus, it is importanrt to study the toxicity of abamectin to P. clarkii. The previous studies of our laboratory showed that with increasing of abamectin concentration, the molting frequency of P. clarkii increased but growth slowed down. We speculated that it was related to energy metabolism. This study attempted to explore the effect of abamectin on energy metabolism of P. clarkii by analyzing TCA cycle. The results showed that the response mechanisms of TCA cycle to abamectin in P. clarkii were different in hepatopancreas and gills. Due to the different absorption and accumulation rates of toxic substances in hepatopancreas and gills, the biochemical indexes and genes expression levels of hepatopancreas decreased with the increasing of abamectin concentration, while the indexes increased in gills. And the continuous abamectin stress could also cause irreversible damage to gills. As an important hub of lipid-, glucose-, and amino acid-metabolism, once TCA cycle was blocked, the growth of P. clarkii was slow, the immunity and the reproductive capacity were decreased. This study provided a guidance for healthy culture of P. clarkii , and a theoretical basis for further study on energy metabolism of crustaceans. • Toxicity of abamectin to gills in P. clarkii was weaker than to hepatopancreas. • Continuous low-dose abamectin stress caused irreversible damage to P. clarkii. • Abamectin disturbed TCA cycle affecting lipid-, glucose-, amino acid-metabolism.