Sterols in marine invertebrates

The sterol composition of marine invertebrates, crustaceans, molluscs, echinoderms, coelenterates, and sponges has been re-examined by using improved analytical techniques. As a result, the sterol composition of marine invertebrates has been shown to be more complex mixtures including many new types of sterols with unusual steroid nuclei or with non-conventional side chains. Some crustaceans and molluscs are of importance as seafood and aquaculture species. Crustaceans and some molluscs require dietary sources of sterol for growth and survival because of the absence of de novo sterol-synthesizing ability. The present paper gives a review of the requirement and nutritive value of sterols, biosynthesis and metabolism of sterols, and composition and structure of sterols in marine invertebrates.