Asian Mussel, Musculista senhousia

The Asian mussel, Musculista senhousia, is a small seawater mussel, a marine bivalve mollusk species belonging to the family Mytilidae. It is different from the other mollusks by its relatively small size and inflated shape, as well as the greenish color of its outer periostracal layer. It also has radiating reddish lines on its posterior, small internal teeth on the dorsal edge posterior to the ligament of the shell, and small ribs anterior to the umbones. It has the potential to grow up to 30 millimeters in length. It’s also known for its relatively fast growth and has a maximum lifetime of about two years.

It is native to the Pacific Ocean, inhabiting the coastal areas from Siberia and the Kuril Islands south to Singapore. It is an invasive species in California, the Mediterranean, Australia, and New Zealand. It was introduced to the Western coast of the United States sometime in the early twentieth century with shipments of Japanese oysters.

It is generally found in sheltered mud or other soft substrates up to 20 meters below the surface of the water. In China and Japan, the native mussel is found in intertidal zones with densities up to 2500 individuals per square meter.

This mussel uses byssal threads to create a sort of cocoon around itself. The cocoon may be necessary for protection because of the relatively thin shells of the species as well as to assist in the stabilization of the species in the sediment. The cocoons of each individual can intertwine to form a mat that has a tendency to collect shells, algae, sediment, and detritus on its surface.

Image Caption: Musculista senhousia (Asian mussel) from Auckland, New Zealand. Credit: GrahamBould/Wikipedia