The oyster is a small sea ani­mal enclosed in two hinged shells called valves. Oysters belong to a group of mollusks called bivalves (two-valves). Varieties are used for food, mother-of-pearl, and pearl production. Oysters are found mainly in waters off sea coasts.
   The full-grown oyster's shell is the size of a woman's hand, appearing grayish colored and irregularly pear-shaped. One valve is larger and cupped, holding the animal's soft body. The other is like a lid on a box. The inside of the valves is made smooth by a secretion of the oyster. This is "mother-of-pearl." Its smoothness protects the soft, naked animal. The valves open and close slightly, controlled by adductor muscles, located on either side of the body. Oysters breathe by gills and eat minute plants and animals in the water. To remove an oyster, one must force the shell open by cutting the strong muscles at the hinge with a sharp knife.
   Oysters develop from eggs, one oyster producing hundreds of millions of eggs in a season. This large number of eggs is vital, for quantities are eaten by fish, which also devour the larvae (small swimming forms which develop into adults. These swimmers travel about for two weeks until they anchor permanently. They continue to grow, arriving at full growth in three to four years.
   Commercially, oyster "beds" are kept in favorable condition for, oyster production and development. Since oysters live such perilous lives, "farmers" must do all they can to guard their investment by careful attention to oyster needs.