What is "blue mussel"

n. A medium-sized edible mussel, ''Mytilus edulis'', found on the North Atlantic coast of North America, Europe, and in other temperate and polar waters around the world.

The blue mussel (Mytilus edulis), also known as the common mussel, is a medium-sized edible marine bivalve mollusc in the family Mytilidae, the mussels. Blue mussels are subject to commercial use and intensive aquaculture.