Role of membrane lipid in osmoregulatory processes during salinity adaptation: a study with chloride cell of mud crab, Scylla serrata

A significant variation in membrane fluidity, lipid composition, fatty acids profile and intra-extracellular ion concentrations of chloride cells was observed in the estuarine mud crab, Scylla serrata, when they were acclimated to 1 and 35 psu. About 60% decrease in K-m and V-max of Na+/K+-ATPase, Mg2+ ATPase and Ca2+ ATPase enzymes and 85% increase in the same was observed when the crabs were acclimated to 1 and 35 psu saline water, respectively. The changed membrane lipid bilayer composition and fluidity of the plasma membrane of chloride cell help in modulating activity of Na+/K+-ATPase and thus regulate the ionic composition of the cell during salinity adaptation.