Evergreen Natural History Database

Common name(s): Blue Mussel

Size:
Up to 110 mm

Range:
N. Alaska to N. California

Habitat:
Usually found in quiet bays but also occurs along the outer coast along with Mytilus californianus (the California Mussel). Normally found through the intertidal-zone to a depth of 5 m. The preferred substrate is rock, wood or some other solid structure.

Misidentification:
Sometimes this mussel is mistaken for M. californianus (California Mussel) or M. edulis (Bay Mussel).

Life History:
This species spawns when water temperatures reach 12^oC, around May, where the females release three to six million eggs into the water column. After living planktonically for approximately four weeks, the larvae settle out on algae encrusted substrate and metamorphose into the adult form. M. trossulus, like M. californianus and M. edulis, form dense mats along the intertidal zone. As silt deposits increase within these mats, those mussels in the center will move or "crawl" to the outside of the mat to prevent their being buried and smothered.

Predators:
Pisaster spp. and Nucella emarginata

*"Size" refers to shell length only and only gives the largest average size for the given species.

Last updated Tuesday, August 29, 2006, by Lisa Ferrier