Effects of thermal acclimation on the lipid metabolism in the earthworm Lampito mauritii

Abstract

1. 1. Changes in the total lipid and phospholipid content, the degree of unsaturation of lipids, the lipase activity, the levels of oxaloacetic, acetic and formic acids, the ketone bodies and the cholesterol content, on thermal acclimation of the tropical earthworm, Lampito mauritii, were studied. 2. 2. The total fat content, the formic and oxaloacetic acid levels decreased significantly on acclimation to a decreasing temperature (P < 0·0001, 0·01 and 0·05 respectively). 3. 3. The unsaturation of lipids, the enzyme lipase activity, the levels of acetic, β-hydroxy butyric and acetoacetic acids and cholesterol showed a significant increase on cold temperature adaptation. The t values were 5·947, 5·917, 3·297, 8·354 3·015 and 12·70 respectively. 4. 4. The percentage increase in the levels of phospholipids and acetone on acclimation to cold temperature was +10·9 and +75·8 respectively. 5. 5. The adaptive significance of the constituents studied is discussed.