Oysters   Species Overview

Kumamoto Oyster

Crassostrea sikamea

Originally introduced from southern Japan’s Kumamoto Prefecture this oyster is smaller than the Pacific oyster and has a very deep cup. The “Kumo” oyster can’t spawn in the colder waters of Puget Sound, so growers must rely on hatchery stock to produce marketable oysters.







Olympia Oyster

Ostreola conchaphila

Native to the Pacific coast of North America the Olympia oyster was once the dominant species in Washington State. Prized for it’s sweet flavor, this delectable oyster,with its small, rounded shell is found hidden in the calm coves of Puget Sound and Willapa Bay. Olympia oysters are internal brooders and release a limited number of juveniles at each spawn, and are augmented by hatchery seed.




Pacific Oyster

Crassostrea gigas

First introduced from Japan in 1902, the Pacific oyster has become the mainstay of Washington State’s oyster industry. The fluted, chalky-white or gray shells are often attached to rocks or older oyster shells, sometimes in a cluster. Depending on conditions, Pacific oysters reach four to six inches in length in two to four years and can naturally reproduce by broadcast spawning into the water or via hatchery spawning. Pacific oyster farming has evolved to provide a tumbled product that creates a deep cup without fluted edges to the market place.



European Flat Oyster

Ostrea edulis

Originally introduced from Europe, the European flat oyster does not occur naturally in Washington but has been grown commercially in Puget Sound. The circular shell is almost flat, reaching about four inches in size within three to four years. European flat oysters require hatchery seed for production.