Species At Risk

Black Redhorse

(Moxostoma duquesnei)


Black Redhorse
Black Redhorse occurrences map


The Black Redhorse fish is a member of the sucker family. It grows to about 50 centimetres in length and weighs up to one kilogram. It has a long, rounded snout and a downward facing, typical sucker mouth. The back is grey, brassy or olive brown with a silvery blue overtone. The sides are a silver blue and the belly is silver or milky white. The fins are usually a slate grey colour but the fins (especially those on the bottom of the body) can be pale orange.


In Canada, the Black Redhorse is found only in southwestern Ontario at a few locations in the Bayfield River, Maitland River, Ausable River, Grand River, Thames River, and Spencer Creek watersheds.


In Ontario, the Black Redhorse lives in pools and riffle areas of medium-sized rivers and streams that are usually less than two metres deep. These rivers usually have few aquatic plants, a moderate to fast current, and a sandy or gravel bottom. In the spring, it migrates to breeding habitat where eggs are laid on gravel in fast water. The winter is spent in deeper pools. Adults feed on crustaceans and aquatic insects, while the young fish feed on plankton.


In Ontario, availability of suitable habitat, including breeding habitat, is the main limiting factor to the Black Redhorse. It requires clean, clear water and does not do well in rivers that are muddy or polluted. Urbanization in the Grand and Thames watersheds represents a threat to these populations. Dams and other barriers that can limit fish movement are also considered a threat.


The Black Redhorse is protected under Ontario’s Endangered Species Act.

What You Can Do to Help the Black Redhorse

  • The Ministry of Natural Resources tracks species at risk such as the Black Redhorse. You can use a handy online form to report your sightings to the Natural Heritage Information Centre. Photographs with specific locations or mapping coordinates are always helpful. nhic.mnr.gov.on.ca
  • Report any illegal activity related to plants and wildlife to 1-877-TIPS-MNR (847-7667).
  • Invasive species seriously threaten many of Ontario’s species at risk. To learn what you can do to help reduce the threat of invasive species, visit: ontario.ca/invasivespecies ; www.invadingspecies.com ; www.ontarioinvasiveplants.ca ; and, www.invasivespecies.gc.ca .
  • Volunteer with your local nature club or provincial park to participate in surveys or stewardship work focused on species at risk.
  • Private land owners have a very important role to play in species at risk recovery. If you find Black Redhorse 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 the breeding season, the body colour of the male Black Redhorse changes from bluish-silver to a darker greenish-black.

Did you know?

The Black Redhorse looks very similar to the golden redhorse. Experts look closely at the lips, tail fins, and the number of scales to correctly identify the species.

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.