Fisheries Program
Northeast Region

Dwarf wedgemussel (Alasmidonta heterodon)

Life History

Dwarf wedgemussels are filter feeders. They filter plankton. These mussels prefer streams with slow to moderate current and bottoms that are silt-free. The females carry eggs in their gills where they are fertilized after males release sperm into the water. The larvae or glochidia are released from the gills but must attach to a fish host to survive. The glochidia drop off the fish once they have grown into juvenile mussels. Once on the bottom, they grow into adults.


North Carolina to Canada. In this region, they are found in CT, MD, NH, NY, VA and VT

Fun Facts

  • The dwarf wedge mussel was listed as an endangered species in 1990.
  • Their shells are about 1.5 inches long.
  • Fish hosts include sculpin, tessellated darter and Johnny darter.

More Information

Dwarf wedgemussel recovery plan (pdf - 2.20MB)

Back to Aquatic Species Profiles
Last updated: December 16, 2011
Northeast Fisheries Program Home
Northeast Region Home

U.S. Fish and Wildlife Service Home Page | Department of the Interior  |  | About the U.S. Fish and Wildlife Service  | Accessibility  | Privacy  | Notices  | Disclaimer  | FOIA