ETYM Old Fren. oistre, French huître, Latin ostrea, ostreum, Greek ostreon; prob. akin to ostreon bone, the oyster being so named from its shell. Related to Osseous, Ostracize.
Bivalve mollusk constituting the Ostreidae, or true oyster, family, having the upper valve flat, the lower concave, hinged by an elastic ligament. The mantle, lying against the shell, protects the inner body, which includes respiratory, digestive, and reproductive organs. Oysters commonly change their sex annually or more frequently; females may discharge up to a million eggs during a spawning period.
Among the species commercially exploited for food are the North American eastern oyster Crassostrea virginica of the Atlantic coast and the European oyster Ostrea edulis. The former is oviparous (eggs are discharged straight into the water) and the latter is larviparous (eggs and larvae remain in the mantle cavity for a period before release). Oyster farming is increasingly practiced, the beds being specially cleansed for the easy setting of the free-swimming larvae (known as “spats”), and the oysters later properly spaced for growth and fattened.
Valuable pearls are not obtained from members of the true oyster family; they occur in pearl oysters (family Pteriidae). There are also tree oysters (family Isognomonidae) and thorny oysters (family Spondylidae).
1. A small muscle on each side of the back of a fowl.
2. Marine mollusks having a rough irregular shell; found on the sea bed mostly in coastal waters. + prikaži više