Variation in lipid classes during the molting cycle of a shrimp.

Abstract

This study deals with the variations in the content and fatty acid composition of lipid classes during the molting cycle of a fresh-water shrimp, Palaemon paucidens. The lipid content increased at mid premolt (stage D2) and then decreased at late premolt (stage D3-4). The accumulation of lipids during the early premolt period seemed to be attributed mainly to that of polar lipids. Throughout the molting cycle, the shrimp con-tained more polar than neutral lipids, the latter consisting mainly of triglycerides, free sterols, and free fatty acids. In the case of the polar lipids, the percentage composition of saturated acids such as 16:0 and 18:0 increased at stage D2. In contrast to the polar lipids, the tri-glycerides showed no marked variation in the fatty acid composition during the molting cycle. The free fatty acids showed an increase in saturated acids such as 16:0 and monoenoic acids such as 16:1 and 18:1 at intermolt (stage C).