Metabolic mechanism of Scylla paramamosain gill mitochondria in response to acute low salinity stress

Salinity affects the growth and development of crustaceans by affecting their physiological functions such as respiration, metabolism, osmotic regulation and immune defense. Gill is the most important organ of osmotic regulation. The adaptation of Scylla paramamosain to low salt is a process of oxygen consumption and energy consumption, and the mitochondria in the cells are considered to be the synthesis site of energy. Therefore, in this study, GC-MS technology was used to conduct non-targeted metabolomics studies on the posterior gill mitochondria of S. paramamosain under acute hyposaline stress, revealing the key role of mitochondria in gill response to acute low salinity stress. We identified 196 metabolites, 21 of which were differentially expressed. Differential metabolite KEGG enrichment analysis identified 16 metabolic pathways. The results of this study suggest that mitochondria may maintain osmotic homeostasis by increasing the utilization of monosaccharides, and decreasing the synthesis of amino acids in crabs under acute low salt stress when they are in a state of oxygen and energy depletion. In addition, carbohydrates and organic acid metabolites may also play an important role. For the first time, we analyzed the metabolic mechanism of posterior gill mitochondria in response to acute low salt, aiming to provide effective technical support and theoretical reference for the cultivation of S. paramamosain.