TEMPERATURE ACCLIMATION OF MARINE CRABS: CHANGES IN PLASMA MEMBRANE FLUIDITY AND LIPID COMPOSITION

Abstract 1. 1. Crabs were acclimated for 3 weeks to cold and warm temperatures. Plasma membranes prepared from leg muscle were analysed for fluidity and lipid composition. 2. 2. Plasma membranes from cold-acclimated crabs were more fluid and had lower cholesterol to phospholipid ratios than those from warm-acclimated crabs. The ratio saturated/unsaturated fatty acids was little altered by temperature acclimation. 3. 3. Plasma membranes from the stenothermal species ( Cancer pagurus ) were slightly more fluid (at DPH probe level) and had lower cholesterol/phospholipid ratios than those from the eurythermal species ( Carcinus maenas ). 4. 4. Plasma membranes from crabs acclimated in spring had more saturated and less polyunsaturated fatty acids than those from crabs acclimated in autumn.