Aspects of phospholipid metabolism in crustaceans as related to changes in environmental temperatures and salinities

Abstract 1. 1. The biosynthesis of certain phospholipids, phosphatidylethanolamine (PE), diphosphatidyl-glycerol (DPG), and especially phosphatidylserine (PS), is in part implicated in anisosmotic extracellular regulation in Crustacea. 2. 2. The principal result is that the Na + , K + -ATPase activity of the posterior gills seems to depend highly on the presence of PS. 3. 3. The composition and the synthesis of phosphatides do not appear to play an important part in the isosmotic intracellular regulation except the reaction of PE to PC (phosphatidylcholine) which could provide some quaternary ammonium bases. 4. 4. In contrast phosphatidyl inositol (PI) is the phospholipid which seems to be the least implicated in the acclimation mechanism. 5. 5. The relative constancy of PI in crab tissues may mean that PI in these Crustacea has a highly specific role in biomembrane function similar to those in vertebrate membranes.