The effect of the environmental temperature on the fatty acid composition and on thein vivo incorporation of 1-(14)C-acetate in goldfish (Carassius auratus L.).

Two-year-old goldfish were adapted to 10C and 35C environmental temperatures during a three-week period, and the fatty acids from triglycerides and certain phospholipids were analyzed by gas-liquid chromatography. Over-all unsaturation of the major fatty acids increased with lower temperature in all lipids which were examined although fish maintained at 10C actually had less polyenoic acid in their tissues than did those maintained at 35C.Fish acclimated to 10C and 30C were injected with 1-(14)C-acetate, and the activities of the isolated fatty acids were counted. The incorporation of(14)C into the fatty acids was much greater at the lower temperature. A comparison of the activities of saturated and unsaturated fatty acids within each temperature group revealed a tendency toward higher incorporation into the unsaturated acids at lower temperature. The possible correlations between accelerated biosynthesis of polyenoic acids and the lower tissue levels of these acids in the cold-adapted fish are discussed.