Species At Risk

River Redhorse

(Moxostoma carinatum)

Special Concern

River Redhorse
River Redhorse occurrences map


The River Redhorse is a large, thick-bodied sucker with a large, flat-topped head, a prominent snout and a red-tinted tail fin. It has a white belly, brown or olive green back and brassy, yellowish-green or coppery sides. It can grow to a size nearing 80 centimetres and weigh more than 5.5 kilograms.

Action we are taking:


The River Redhorse lives in scattered locations through central and eastern North America including Ontario and Quebec. In Ontario, it has been found in the Bay of Quinte, and the Trent, Grand, Thames, Ottawa, Mississippi, and Madawaska rivers.


The River Redhorse inhabits medium to large-size rivers that have substantial flows. In May and June, adults migrate from deeper, slower moving pools and run habitats to shallow riffle-run habitats having coarse substrate and moderate to swift flow.


The River Redhorse requires clear and unpolluted water and is therefore susceptible to siltation and turbidity that can result from farming and urban development. Dams are also a threat as they can alter habitat conditions and prevent migrating fish from reaching traditional breeding areas or other important habitats.


The River Redhorse is listed as a species of Special Concern under Ontario’s Endangered Species Act. Although species of Special Concern do not receive legal protection under this act, this species does receive general protection provided by habitat sections of the federal Fisheries Act.

What You Can Do to Help the River Redhorse

  • The Ministry of Natural Resources tracks species at risk such as the River 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).
  • Private land owners have a very important role to play in species at risk recovery.You may be eligible for stewardship programs that support the protection and recovery of species at risk and their habitats.
  • Farmers and land owners can help improve fish habitat and keep Ontario’s water safe and clean by maintaining natural vegetation next to creeks and rivers, and keeping pollution and soil from washing into Ontario’s streams and rivers. For more information about programs and funding assistance for eligible land owners visit the Ontario Soil and Crop Improvement Association website at www.ontariosoilcrop.org/en/programs/species_at_risk.htm.
  • Volunteer with your local nature club or provincial park to participate in surveys or stewardship work focused on species at risk.

Did you know?

The River Redhorse is one of six species of redhorse in Ontario, which can be difficult to tell apart. To help separate the six species, biologists look closely at the number of scales along their sides and around their tail, features of their lips and the colour of their tail.

Did you know?

The maximum age reported for River Redhorse in Canada is 28 years.

Did you know?

The bottom-feeding River Redhorse uses its fleshy lips, highly charged with nerve endings, to feel for food along river beds. The River Redhorse does not have teeth on its jaw but rather uses molar-like teeth in its throat to crush its food.

Did you know?

River Redhorse males construct nests in clean gravel by sweeping with their tail, carrying rocks with their mouths or moving the underlying material with their heads. The nests are excavated to a depth of 20 to 30 centimetres and may be up to 1.2 to 2.4 metres across.

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.