Mediterranean mussel

Appearance

This animal grows up to 140 mm in length. It is a smooth-shelled mussel with a slightly broader base than that of the black mussel , with which it is often confused in South Africa. Its shell is blue-violet or black, but may shade to light brown.

Distribution

In Europe, ''Mytilus galloprovincialis'' is found in the Mediterranean Sea and the Black Sea, and on the Atlantic coasts, in Portugal, north to France and the British Isles and Norway. Recently this species has also been found in the European Arctic including northern Norway and Svalbard

In the northern Pacific the species is found along the coast of California, where it was introduced from Europe by human activity in the early 20th century, and also in the Puget Sound region of Washington State, where it has been subject to aquaculture. It is also present as an invasive species on the Asian coast throughout Japan, including Ryukyu Islands, as well as in North Korea and around Vladivostok in Russia.

''Mytilus galloprovincialis'' is also present as a native lineage in parts of the Southern Hemisphere. In addition there are populations introduced from the north recently with human activity. These lineages are distinguished by genetic characters. No original ''Mytilus'' populations lived in southern Africa, but the Mediterranean mussel was introduced from Europe in 1984 and is now the dominant low intertidal mussel on the West Coast. The distribution spans an area from the Namibian border to Port Alfred, intertidally to just below the low tide border. ''M. galloprovincialis'' is also found in New Zealand, Australia and South America.

Habitat

The Mediterranean mussel is a filter feeder. It is rare subtidally, which is an alternate means of distinguishing it from the black mussel in South Africa.