oyster plant, name for several plants, among them the salsify.

oyster catcher, common name for members of the family Haematopodidae, ploverlike shorebirds, cosmopolitan in distribution. Their distinctive red bills are long, blunt, and flattened, efficient for catching and opening the oysters, mussels, and clams on which they feed. They are noisy birds, larger (21 in./52 cm) and more brightly marked than most other shorebirds. Species found in America are the black, European, and Frazer's oyster catchers of the genus Haematopus. Oyster catchers nest in shallow, debris-lined cavities in the sand. They lay two to four eggs per clutch, and both male and female share incubation duties. Oyster catchers are classified in the phylum Chordata, subphylum Vertebrata, class Aves, order Charadriiformes, family Haematopodidae.

oyster, edible bivalve mollusk found in beds in shallow, warm waters of all oceans. The shell is made up of two valves, the upper one flat and the lower convex, with variable outlines and a rough outer surface. Since the oyster spends most of its life (except for the free-swimming larval stage) attached—having fused its valve with a sticky substance to a substratum of shells, rocks, or roots—the foot is rudimentary. In some species the sexes are separate and the eggs are laid and fertilized in the water; in others the animal is hermaphroditic and the eggs are retained with the shell. Only a small proportion of the millions of eggs laid survive. Large numbers of the free-swimming larvae, called veligers, are consumed by fish and other animals. After the oyster becomes sessile, it is victimized by oyster drills, starfish, and other enemies. Most species are too small for food, but the American, or common, oyster reaches a length of 2 to 6 in. (5-15 cm). These oysters are harvested in artificial beds on both coasts of the United States: on the Atlantic especially in the regions of the Delaware and Chesapeake bays and in the waters off Long Island, in the Gulf Coast off Louisiana, and in the Pacific off the state of Washington. Prepared beds are usually seeded with veligers or young sessile oysters called spats. In warm waters they mature in 11/2 years; in cooler waters the period of growth is about 4 to 5 years. They are usually transplanted several times before harvest to enhance their food supply and stimulate growth. The wing and the pearl oysters are widespread in warmer seas; there is one eastern and one western species of each in American waters. The great pearl oyster, from which the pearl is obtained, is a large (12-in./30.5-cm) tropical species. Oysters are classified in the phylum Mollusca, class Pelecypoda or bivalvia, order Filibranchia, family Ostreidae.

Oyster Bay, uninc. area (1990 pop. 6,687) of the Town of Oyster Bay, Nassau co., SE N.Y., on N Long Island, on Long Island Sound; settled 1653. It is chiefly residential. Nearby is Theodore Roosevelt's estate, "Sagamore Hill," which was made a national shrine in 1953 and a national historic site in 1963. Also of interest in Oyster Bay are several 18th-century homes and the Theodore Roosevelt memorial bird sanctuary (owned by the National Audubon Society), which adjoins Roosevelt's grave.

or oyster plant or vegetable oyster

Biennial herbaceous plant (Tragopogon porrifolius) of the composite family, native to the Mediterranean. The thick white taproot is cooked as a vegetable and tastes somewhat like oysters. The plant has purple flowers and narrow leaves whose bases usually clasp the stem. Goatsbeard, or meadow salsify (T. pratensis), is a weedy European species, naturalized in North America, that has a large yellow flower head. It is occasionally cultivated as an ornamental, and its leaves, flowers, and roots are sometimes eaten in salads.

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Any bivalve of two families, Ostreidae (true oysters) or Aviculidae (pearl oysters), found in temperate and warm coastal waters worldwide. Both valves (halves) have a rough, often dirty-gray outer surface and a smooth white inner lining (nacre). The lower valve, which affixes to a surface, is nearly flat. The smaller upper valve is convex and has rougher edges. The oyster filters its food, minute organic particles, from the water. Cultivated as food, oysters are regarded as a delicacy. Pearls are the accumulation of nacre around a piece of foreign matter.

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