Among aquatic creatures, molluscs are one of the main phylums of marine organisms because of their vast biodiversity, nutrition advantages and their natural compounds. Chemical ecology discusses study of natural compounds in organisms, analyzes their structures and tracing their production and variation in response to environmental parameters. There are about 600 natural compounds identified, in which their metabolism are studied more in four classes of molluscs: polyplacophora, gastropoda, cephalopoda and bivalves. The main identified compounds are amino acids, lipids and fatty acids, terpens and steroids. Fatty acids and lipids are the main pre-structures for biological membranes, and their physical characteristics create membrane structure and its activities. Therefore, many cell functions depend on membrane activity and chemical composition of membrane lipids and environmental parameters as follows. Normally, the omega 6 to omega 3 ratio has moderate amounts in natural food sources. The more the ratio closer to 1, the more body metabolism could be sensitive for absorption. Environmental parameters, such as temperature, salinity, pH and food type source, could change the amount and structure of natural compounds. Biological factors such as sex type, reproduction and breeding cycles, different tissues and their activities could receive different types of natural compounds.
Part of the book: Biological Resources of Water