Analysis based on osmoregulatory enzymes and LC-MS technology for the adaptation of antennal gland of mud crabs (Scylla paramamosain) to acute chloride type low-salt saline-alkali water stress

The mud crab ( Scylla paramamosain ) is an important species for seawater aquaculture, the utilization of saline-alkali water provides potential for the further development of the mud crab industry, but the adaptation mechanism of the antennal gland to chloride type low-salt saline-alkali water has not been fully studied. In this study, we evaluated the osmoregulatory enzyme activity (n=3) and metabolic changes (n = 5) of the antennal gland in S. paramamosain after a sudden drop in salinity from 23 ‰ of seawater to 2 ‰ of chloride type low-salt saline-alkali water. After the decrease in salinity, the activity of osmoregulatory enzymes in the antennal gland, including Na + /K + -ATPase, NKCC, carbonic anhydrase (CA), and V-ATPase showed a trend of first increasing and then decreasing. Through LC-MS technology, we identified 308 differential metabolites. In addition, KEGG enrichment analysis identified eight significant metabolic pathways ( P <0.05), primarily related to amino acid metabolism, signaling pathways, and lipid metabolism. Among them, amino acid and energy metabolism occupy the majority, followed by lipid metabolism pathways. Our research results indicate that amino acids and energy metabolism are involved in the adaptation of the antennal gland of the mud crab to acute chloride type low-salt saline-alkali water stress, in which lipid metabolites play an important supportive role. • NKA, NKCC, CA and V-ATPase initially increased and then decreased. • LC-MS technology has been applied for the first time in the antennal gland. • Energy metabolism (mainly lipids) involved in the adaptation of the antennal gland.