Effects of Lecithin on Cholesterol Digestibility in the Prawn, Artemesia longinaris (Crustacea, Penaeidae)

Abstract

Cholesterol and dietary phospholipids are important to the growth and survival of crustaceans. Soy lecithin enhances cholesterol solubilization while phosphatidylcholine transfers cholesterol from the hepatopancreas to the hemolymph. To study the influence of dietary lecithin on digestibility and transport of cholesterol to the hemolymph in Artemesia longinaris, diets with dif- ferent levels of supplemental cholesterol (0.5, 1, 1.5, and 2%) and soy lecithin (0, 0.5, 1, and 2%) were fed to prawns for two weeks. The diet containing the lowest level of cholesterol (0.5% ) and lecithin (1%) resulted in the lowest apparent digestibility of cholesterol. The diets containing 2% cholesterol and 1% or 2% lecithin resulted in the highest hemolymph cholesterol contents. There was a linear relationship (r = 0.832; p<0.01) between hemolymph cholesterol and the amount of lecithin in the diet. There were no significant differences between treatments in cholesterol con- tents in the hepatopancreas. In a second 6-week experiment, diets containing 1.5% cholesterol significantly improved weight gains, regardless of the lecithin content. Survival rates did not dif- fer among treatments. Hence, the efficacy of cholesterol does not seem to be related to dietary inclusion of lecithin.