Species At Risk


(Lepomis gulosus)

Special Concern

Warmouth occurrences map


The Warmouth is a small sunfish about 30 centimetres long. It has a round, deep body with a long dorsal fin, comprised of both soft and spiny rays. The Warmouth is usually yellow-brown to golden on the top and sides and paler on the underside. Often the Warmouth has five dark lines extending from the snout and eye and radiating across the cheek. It has a large mouth with a projecting lower jaw and a band of tiny teeth on the tongue.

Action we are taking:


The Warmouth is found in the eastern United States, from the lower Great Lakes south to Florida, and west to Kansas. In Canada, the species has been reported in Lake Erie at Rondeau Bay, Long Point Bay and Point Pelee.


The Warmouth, a warm-water species, prefers silt-free marshes, ponds and lakes with abundant aquatic plants and mucky bottoms. Males gather in loose colonies in spring and early summer and build nest depressions for the females to lay eggs. The males then guard their nest and eggs fiercely. Spawning occurs at one to two years of age, and females lay 800 to 34,000 eggs depending on their size. They can live up to eight to nine years.


The Warmouth was first recorded in Ontario in 1966 and may be a relative newcomer to the province. Alternatively, it could have gone undiscovered because it was always rare here. Habitat loss due to the draining of wetlands for agricultural and urban development is the main threat to this species, though current Ontario populations live in protected areas and are in no immediate danger.


The Warmouth 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. Both of the known Ontario populations of Warmouth are in national or provincial parks where the habitat is also protected from destruction.

What You Can Do to Help the Warmouth

  • The Ministry of Natural Resources tracks species at risk such as the Warmouth. 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.
  • Volunteer with your local nature club or provincial park to participate in surveys or stewardship work focused on species at risk.
  • 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.

Did you know?

The Warmouth feeds on small fishes, crayfishes and aquatic insects, and is likely to eat proportionally more fishes than most sunfishes.

Did you know?

The Warmouth can be mistaken for the more common Rock Bass, however, counting the number of anal spines will easily distinguish the two (Rock Bass having six, and Warmouth having three).

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.