Species At Risk


(Truncilla donaciformis)




The Fawnsfoot is a small, 35 to 45-millimetre- long freshwater mussel. Its yellowish to greenish-brown shell is smooth with dark green rays broken into v-shaped markings called chevrons. Although the time for a Fawnsfoot to grow to maturity is unknown, the average age of maturity for similar species is 6-12 years.


Fawnsfoot is only found in North America, where it primarily occurs in the Great Lakes and Mississippi drainages. In Canada, this species is limited to tributaries of the Great Lakes. In most areas where Fawnsfoot occurs, it has a patchy distribution and is limited to the lower portions of large rivers.


The Fawnsfoot inhabits medium and large rivers with moderate to slow flowing water. It usually inhabits shallow waters (one to five metres deep) with gravel, sand or muddy bottoms.


The introduction and spread of invasive mussels has caused major changes to Fawnsfoot habitat, resulting in the species’ decline. Invasive mussels compete for habitat and interfere with native mussels’ feeding, respiration, locomotion and reproduction. Declining water quality in the upper portions of watersheds likely has negative effects on the species.


The Fawnsfoot is endangered and receives automatic species protection under Ontario’s Endangered Species Act. General habitat protection also protects the species’ habitat from damage and destruction. A recovery strategy and a species-specific habitat regulation are being developed.

Fawnsfoot has also been assessed nationally as an endangered species by the federal Committee on the Status of Endangered Wildlife in Canada (COSEWIC).

What You Can Do to Help the Fawnsfoot

  • Contact your local Ministry of Natural Resources office for more information about programs such as the Community Fisheries and Wildlife Improvement Program (CFWIP) to find out how you can become involved in hands-on fish and wildlife management activities. http://www.mnr.gov.on.ca/en/Business/LetsFish/2ColumnSubPage/STEL02_166030.html
  • Report any illegal activity related to plants and wildlife to 1-877-TIPS-MNR (847-7667).
  • Private land owners have a very important role to play in species at risk recovery. If you find Fawnsfoot in a watercourse on or adjacent to your property,you may be eligible for stewardship programs that support the protection and recovery of species at risk and their habitats.

Did you know?

During their immature stage, Fawnsfoot are parasitic and attach themselves to the gills of a fish. They travel with their host, feeding on its body fluids until they develop into juveniles and release to carry out a free-living life cycle.

The Endangered Species Act

Contact your local ministry office

Often the best source of local information on species at risk is your nearest ministry office. Call with your questions or concerns.