The American Oyster, Crassostrea virginica Gmelin

NOTE.-Approved for publication April 24, 1964. The family Ostreidae consists of a large number of edible and nonedible oysters. Their distribution is confined to a broad belt of coastal waters within the latitudes 64° N. and 44° S. With few exceptions oysters thrive in shallow water, their vertical distribution extending from a level approximately halfway between high and low tide levels to a depth of about 100 feet. Commercially exploited oyster beds are rarely found below a depth of 40 feet. The· name "Ostrea" was given by Linnaeus (1758) to a number of mollusks which he described as follows: "Ostrea. Animal Tethys, testa bivalvis inaequivalvis, subaurita. Cardo edentulus and fossula cava ovata, striisque lateralibus transversis. Vulva anusve nullus." The name Tethys (from Greek mythology and also refers to the sea) applies to the type of marine animals, living either within the shells or naked, that Linnaeus listed under a general name "Vermes" which includes worms, mollusks, echinoderms, and others. The translation of Linnaeus' diagnosis reads as follows: Shell bivalve, unequal, almost ear-shaped. Hinge toothless, depression concave and oval-shaped, with transverse lines on the sides. No vulva or anus. Taxonomic characters _ SheIL _ Anatomy _ Sex and spawnlng _ Habitat _ Larvll! shell (Prodlssoconch) _ The genera of living oysters _ Genus 08trea _ Genus Cra8808trea _ Genus Pycnodonte _ Bibliography _ Page