Though 18th-century satirist Jonathan Swift once wrote, "He was a bold man that first ate an oyster," this bivalve has been a culinary favorite for thousands of years. The hard, rough, gray shell contains a meat that can vary in color from creamy beige to pale gray, in flavor from salty to bland and in texture from tender to firm. There are both natural and cultivated oyster beds throughout the world. In the United States, there are three primary species of oysters that are commercially harvested — Pacific (or Japanese), Eastern (or Atlantic) and the Olympia. Each species is sold under different names depending on where they're harvested. olympia oysters are rarely larger than 1 1/2 inches and hail from Washington's Puget Sound. The pacific oyster (or Japanese oyster) is found along the Pacific seaboard and can reach up to a foot long. Considered culinarily superior to the Pacific oysters are atlantic oysters (or Eastern oysters), the most well known of which is the bluepoint. Others from the Atlantic seaboard — named for their place of origin — include Apalachicola, Cape Cod, Chincoteague, Indian River, Kent Island, Malpeque and Wellfleet. In Europe, the French are famous for their belon oysters (which are now also being farmed in the United States) and their green-tinged Marennes oysters; the English have their Colchester, Helford and Whitstable oysters; and the Irish have Galway oysters. Fresh oysters are available year-round. Today's widespread refrigeration keeps them cool during hot weather, debunking the old myth of not eating them during months spelled without an "r. " However, oysters are at their best — particularly for serving raw on the half shell — during fall and winter because they spawn during the summer months and become soft and fatty. Shipping costs generally prohibit movement of oysters far from their beds, limiting the abundant supply to local varieties. Live oysters are best as fresh as possible and therefore should be purchased from a store with good turnover. Reject those that do not have tightly closed shells or that don't snap shut when tapped. The smaller the oyster is (for its species) the younger and more tender it will be. Fresh, shucked oysters are also available and should be plump, uniform in size, have good color, smell fresh and be packaged in clear, not cloudy oyster liquor. Live oysters should be covered with a damp towel and refrigerated (larger shell down) up to 3 days. The sooner they're used the better they'll taste. Refrigerate shucked oysters in their liquor and use within 2 days. Oysters are also available canned in water or their own liquor, frozen and smoked. Oysters in the shell can be served raw, baked, steamed, grilled or in specialty dishes such as oysters rockefeller. Shucked oysters can be batter-fried, sautéed, grilled, used in soups or stews or in special preparations such as dressings, poultry stuffings or appetizers like angels on horseback. Oysters are high in calcium, niacin and iron, as well as a good source of protein. See also shellfish.