Biodiversity & Conservation

American oyster - Crassostrea virginica - General information

American oyster

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Distribution map

Crassostrea virginica recorded (dark blue bullet) and expected (light blue bullet) distribution in Britain and Ireland (see below)

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Crassostrea virginica is not listed under any importance categories.

General information

Key Icon Researched by: Susie Ballerstedt Text page icon Refereed by:

Taxonomy icon Taxonomy

Phylum Mollusca Snails, slugs, mussels, cockles, clams & squid
Class Bivalvia Clams, cockles, mussels, oysters, and scallops
Map icon Recorded distribution in Britain and Ireland Introduced to the south east and south west of England and north Wales.
Habitat information icon Habitat information This species can be found on the lower shore and shallow sublittoral. It is a prolific species in its native home and can be found on any hard surface, often becoming long and distorted when overcrowded. It is tolerant to very low salinity.
Text page icon Description Crassostrea virginica is elongate and broadly oval reaching up to 18 cm in length. The left valve is convex and sculptured with concentric ridges and lines whilst the right valve tends to be flat. There are a few irregular radiating ribs on the left valve which do not normally meet or indent the margin. The shell margin is smooth, and the beaks and umbones are not prominent. The inner surface is pearly white or bluish-white, and the outer surface is deep purple or reddish brown in colour. The adductor muscle scar is near the posterior margin.

This review can be cited as follows:

Susie Ballerstedt 2008. Crassostrea virginica. American oyster. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 03/09/2010]. Available from: <http://www.marlin.ac.uk/speciesfullreview.php?speciesID=3082>