WHAT IS AN OYSTER?
An oyster is a shellfish with 2 rough white shells that hook together at one end. The oyster has strong muscles which hold the shell shut. It is very difficult for predators (like people) to pry the shell open. An Eastern oyster is usually 2 to 6 inches long. The inside of the shell has a purple mark where the oyster was attached. The shell is sharp and can cut you! HOW DO THEY GROW THEIR SHELLS? Oyster shells are made of calcium carbonate (lime). The oysters get the chemicals to make their shells from the water they live in. They also have a sort of skin, called a mantle, which spreads this calcium carbonate on the outside of their bodies to form a protective shell. Oysters must live in water that is temperate (warm all year) and not too cloudy. They grow only in areas where salt and fresh water mix together, like salt marshes. Oysters are born as free-swimming plankton (tiny microscopic organisms). When they grow up, they find a place (on mud, coral, trash, or other oyster shells) to
