Ostrea edulis is a species of oyster native to Europe and commonly known as the European flat oyster, Colchester native oyster, mud oyster, or edible oyster (despite this latter name it is not the only oyster that is edible by humans). When mature, O. edulis adults range from 3.8 to 11 centimetres (1.5 to 4.3 in) across. The species naturally ranges along the western and southern coasts of Europe from Norway to Morocco and including most of the British Isles and the Mediterranean coast. Naturally viable populations have appeared in eastern North America from Maine to Rhode Island subsequent to artificial introduction in the 1940s and 1950s.
U.S. oyster growers farm O. edulis in small quantities on both coasts. They are prized for their unique tannic seawater flavor, sometimes described as dry and metallic, and are more expensive than other American oysters. The flavor is considered excellent for eating raw on the half shell.
Ostrea edulis; a) labial palpi b) gills c) mantle d) junction of the two folds of the mantle e) large adductor muscle f) the shell