Blue Mussel

Shell solid, equivalve; inequilateral, beaks at the anterior end; approximately triangular in outline. Hinge line without teeth but with 3 to 12 small crenulations, under the umbones. Margin smooth. Pallial line wide; anterior adductor scar very small, posterior large. External ligament much concealed, extending more than half-way from the beaks to the highest point of the shell. Sculpture of fine concentric lines. Colour purple, blue, sometimes brown, occasionally with prominent dark brown to purple radial markings. Periostracum almost black, dark brown, or olive; interior pearl-white with a wide border of purple or dark blue.

It is widely distributed in the boreal regions of the northern hemisphere, from the western border of the Kara Sea, south to the Mediterranean, North Carolina, California and Japan; it is absent from the high Arctic.

Attains about 6 cm. One shell of 22,8 cm has. Common between 3 and 5 cm in length.

The exact range of M. edulis is not known because of the confusion with other, very similar Mytilus. In Europe it lives on all coasts that have hard substrates.Intertidal to 40 m deepattached by byssus threads to rocks and piers, within sheltered harbours and estuaries and on rocky shores of the open coast, sometimes living in dense masses wherever there are suitable surfaces for attachment.The diet of mussels consists of phytoplankton and detritus filtered from the surrounding water.The dimensions of the species is greatly influenced by its biotope: intertidal shells often remain small, rarely exceding 6 cm, while deep-water shells easily measure 9 cm.

Natural and cultivated. The exploitation of these beds which was manual until recently developed in a giant industry in the fifties. The total catch reported for this species to FAO for 1999 was 121 964 t. The countries with the largest catches were Denmark (96 215 t) and Canada (11 565 t). Marketed fresh, frozen and canned.