Shellfish including soft-bodied animals (molluscs). These animals included in the class of bivalves (animals that have two shells). These animals can serve as a source of protein and minerals to meet the food needs of the community. All shellfish have a pair of shells (also called a graft or valve), which usually mirror symmetry are connected by a ligament (connective tissue). In most shells, there are two adductor muscles that govern the open-shell lid.
Shellfish has no head, but have organs like kidneys, heart, mouth, and anus. Shellfish can be moved to the "foot" organ-like flat and removed from the shell at any time or by opening and closing the shell of a surprise. Shellfish have an open circulatory system (the animal that has no blood vessels). Oxygen comes from a very liquid blood rich in nutrients and oxygen that surrounds the organs. Shellfish eat plankton, by way of filtering. Shellfish are prey to squid and sharks.