Ostrea lurida

Ostrea lurida, common name the Olympia oyster, after Olympia, Washington in the Puget Sound area, is a species of edible oyster, a marine bivalve mollusk in the family Ostreidae. This species occurs on the northern Pacific coast of North America. Over the years the role of this edible species of oyster has been partly displaced by the cultivation of non-native edible oyster species.

Ostrea lurida is now known to be separate from a similar-appearing species, Ostrea conchaphila, which occurs further south, south of Baja California, in Mexico. Molecular evidence has recently confirmed the separate status of the two species. However, previously, for a period of time, Ostrea lurida was considered to be merely a junior synonym of Ostrea conchaphila.

O. lurida been found in archaeological excavations along the Central California coast of the Pacific Ocean, demonstrating that it was a marine species exploited by the Native American Chumash people.

Description

This bivalve is approximately 6 to 8 centimetres (2.4 to 3.1 in) in length. The shell can be rounded or elongated and is white to purplish black and may be striped with yellow or brown. Unlike most bivalves, the Olympia oyster's shell lacks the periostracum, which is the outermost coating of shell that prevents erosion of the underlying shell. The color of the oyster's flesh is white to a light olive green.