High plasticity of the gut microbiome and muscle metabolome of Chinese mitten crab (Eriocheir sinensis) in diverse environments.

Phenotypic plasticity is a rapid response mechanism that enable organisms to acclimate and survive in changing environments. Chinese mitten crab (Eriocheir sinensis) survives and thrives in different and even invasive habitats, thereby indicating its high phenotypic plasticity. However, the underpinnings of the high plasticity of E. sinensis are not comprehensively investigated. In this study, we conducted the integrated gut microbiome and muscle metabolome analysis on E. sinensis collected from three different environments, namely, artificial pond, Yangcheng Lake, and Yangtze River, to uncover the mechanism of high phenotypic plasticity of E. sinensis. Our study presented three divergent gut microbiotas and muscle metabolic profiles that corresponded to the three environments. The composition and diversity of the core gut microbiota (Proteobacteria, Bacteroidetes, Tenericutes, and Firmicutes) varied among the different environments. Meanwhile, the metabolites associated with amino acids, fatty acids, and terpene compounds displayed significantly different concentration levels in the three environments. Results revealed that the gut microbiome community and muscle metabolome were significantly affected by the habitat environments. This finding indicated the high phenotypic plasticity in terms of gut microbiome and muscle metabolome of E. sinensis when it faces environmental changes, which would benefit acclimation and adaptation to diverse and even invasive environments.