Black Redhorse (Moxostoma duquesnei)

Information summary and survey for the consultations on potentially adding Black Redhorse to the List of Aquatic Species at Risk as Threatened – Please provide input by July 18, 2017.


Let your opinion be heard

As part of the consultation process, the Government of Canada would like to hear your comments on the potential impacts of listing the Black Redhorse (Moxostoma duquesnei) as Threatened under the Species at Risk Act (SARA).

Adding a species to the List of Wildlife Species at Risk

The process of listing a species under SARA consists of several steps: it begins with a status assessment by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) and ends with a Government of Canada decision on whether or not to add a species to the List of Wildlife Species at Risk. Public consultations are conducted to gather the opinions of Canadians and are an important step in this process.

About the Black Redhorse

Black Redhorse

 Figure 1. Black Redhorse (Illustration by Joe Tomelleri. Used with permission).

The Black Redhorse, also known as Black Mullet, Finescale Redhorse, and Finsescale Mullet, is a member of the sucker family (Catostomidae) and is one of seven redhorse species found in Canada (Figure 1). In Ontario, the species grows to an average length of 40.0 cm. The maximum known age is 17 years.


Canada is the northern limit of the Black Redhorse global distribution. The current range of Black Redhorse in Canada is restricted to southwestern Ontario. It is found in tributaries of Lake Erie (Grand River), Lake St. Clair, (Thames River), and Lake Huron (Ausable River, Bayfield River, Gully Creek, Maitland River, Saugeen River, and Sauble River) (Figure 2). Black Redhorse hasn’t been found in Catfish Creek (Lake Erie tributary) since 1938 and is considered extirpated from this watershed.

The Black Redhorse is a bottom feeder that consumes crustaceans and aquatic insects. This species is typically found in large warm water streams with clean coarse substrate (gravel and cobble) but has also been observed in areas with sand, silt, and boulders. Juveniles and young-of-the-year occupy shallow pools with substrate consisting of clean pebbles, cobble, and a mixture of sand and silt.

In spring, the Black Redhorse migrates to spawn at the edge of riffles. The species may be an indicator of a healthy aquatic ecosystem as it is intolerant of poor water quality and siltation.


Figure 2. Black Redhorse distribution in Canada.

Proposed SARA Status: Threatened

The level of protection and recovery actions undertaken for a species listed under SARA depends on its assessed level of risk for extinction. In 2015, COSEWIC assessed Black Redhorse within Canada as Threatened. Under SARA, a Threatened species is defined as one that is likely to become an Endangered species if nothing is done to reverse the factors leading to its extirpation or extinction

Why is Black Redhorse at risk?

Black Redhorse is found only in a few rivers in southwestern Ontario, and its habitat is under continuing threat due to the cumulative impacts of pollution from urban wastewater and agriculture, and alterations to stream flow.

If a species is listed under the Species at Risk Act

If the Black Redhorse is listed as Threatened, the prohibitions under SARA would immediately come into effect in Canadian waters. It would be illegal to kill, harm, harass, capture, take, possess, collect, buy, sell, or trade Black Redhorse. Critical habitat (the habitat necessary for the survival and recovery of Black Redhorse) would need to be identified, to the extent possible, in a recovery strategy or action plan and protected from destruction.

Before completing this survey, you may wish to review the following background information found at the links below:

Thank you for completing this survey.

Species at Risk Program
Central and Arctic Region
867 Lakeshore Road
Burlington, Ontario, L7S 1A1

We would like to receive your comments on the potential impacts of adding or not adding Black Redhorse to the List of Wildlife Species at Risk under SARA designated as Threatened. Your comments are important.

Please fill out the survey: we want to hear from you.