MBL March Madness: Softshell Clam

The softshell clam (Mya arenaria) is an important recreational and commercial species in coastal New England and the mid-Atlantic. Clams are a type of mollusk with two shells attached by a muscular hinge. They burrow in sand or mud using a single powerful foot and open their shells to filter feed on microscopic food particles drifting in the water. Softshell clams are an invasive species along the west coasts of the U.S. and Canada.

Clams have transparent eggs and embryos, which makes them ideal for studying cellular and embryonic development. Softshell clams are temperature-sensitive and the southern limit of their range is controlled by the upper water temperatures, making them an interesting species for studying the effects of climate change on bivalves. 

Fun Facts: 

• Mya arenaria are listed on MBL Collection Logs as far back as the late 1800s.
• Softshell clams are especially tolerant of low salinity and quite large changes in salinity and temperature.

They have a particularly high capacity for filtration. Volumes of about one to ten liters per hour have been measured for clams of 2.25 – 2.75 inches in shell length.