About Mytilus trossulus A.Gould, 1850
Mytilus trossulus, commonly called the Pacific blue mussel, bay mussel, or foolish mussel, is a medium-sized edible marine bivalve mollusc that belongs to the family Mytilidae. This species is one of the three main closely related taxa in the Mytilus edulis complex of blue mussels. Together, taxa in this complex are widely distributed across temperate to subarctic coasts of the Northern Hemisphere, and are often dominant inhabitants on hard substrates in intertidal and nearshore habitats. Mytilus trossulus is the primary native intertidal mussel of the Northern Pacific. In North America, its range extends from California to Alaska, while in Asia it occurs from Hokkaido northward. At its southern range limits, it hybridizes with Mytilus galloprovincialis, the Mediterranean mussel, which humans have introduced to the Pacific. In the North Atlantic, M. trossulus occurs on the U.S. coast of Maine and northward into Canada, as well as in scattered locations along North European coasts. In these North Atlantic regions, it frequently coexists and hybridizes with Mytilus edulis. A distinct population of Mytilus trossulus lives throughout the entire Baltic Sea; this population carries some genetic introgression from M. edulis, and its mitochondrial DNA has been replaced by M. edulis mtDNA. In the Arctic, Mytilus trossulus is found in northwest Greenland, where scattered individuals occur in the intertidal zone between 71°N and 77°N.
