Bioconversion of desmosterol to cholesterol at various stages of molting cycle in Palaemon serratus pennant, crustacea decapoda

Abstract

1. 1. The bioconversion of desmosterol to cholesterol during the molting cycle of the shrimp, Palaemon serratus, was investigated in conjunction with the variation of lipids, unsaponifiable matter and sterol concentrations. 2. 2. The lipid concentration was high at stages D 1′ and D 1″ (early premolt). The unsaponifiable matter concentration was high at stages A 2, B 1 and B 2 (postmolt). However, the sterols were contained at an almost constant level in the tissues throughout all the molting stages examined. 3. 3. The ability for conversion of desmosterol to cholesterol rose markedly at stages A 2-B 1, decreased at stage B 2 and then appeared to increase slightly up to stage D 1′ and decreased notably at stages D 1′-D 1″ to the almost constant levels maintained throughout the late premolt (stages D 1‴ and D 2).