Erythrocytes from mature male cod, which had been starved for 1 week, contained 16.5 × 10−13 g lipid per cell, about 75% of which was phospholipid. Cholesterol represented about 11%, triglycerides 5%, free fatty acids 4%, and sterol esters 2% of the total lipid. The fatty acid composition was typical of a marine lipid, and in general erythrocyte lipids closely resembled cod muscle (cellular) lipid.