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