Crassostrea gigas from the Marennes-Oléron basin in France

Oyster reef at about mid-tide off fishing pier at Hunting Island State Park, South Carolina

Oysters served on ice and with a piece of lemon on the side

Chargrilled oysters

Oysters are a family of bivalves with rough, thick shells, the Ostreidae. Some other types of shellfish are also called 'oyster'. Many species are edible, and are usually served raw. They are also good when cooked.

In the past, they were an important food source, especially in France and Britain. They used to grow in huge oyster beds, but were "overfished" in the 19th century. Nowadays they are more expensive, so eaten less often.