Mytilus edulis Linnaeus, 1758
An easily recognizable bivalve, the edible Blue Mussel is a midnight blue/black color with somewhat wing-shaped valves (the two shell halves). It has concentric growth lines and some radial rays, and four small teeth under the beak (pointy area) of the mussel. The shell might reach a length of three inches. The interior of the shell is a pearly gray or white with dark violet borders.
This creature may be seen attached to coastal rocks, pilings of docks, etc., anywhere from the Arctic to South Carolina, and from Alaska to southern Baja California. It is said that Mytilus edulis was spread throughout the coastal waters of the Northern Hemisphere because of the fact that the Blue Mussels, using their thread-like byssus, attach themselves to the hulls of ships, thus traveling great distances; as a result the bivalve is also found in seas of South America. The Blue Mussel is found (and farmed) in Europe as well, where it is eaten much more frequently than in the U.S.