Species At Risk

Spotted Sucker

(Minytrema melanops)

Special Concern

Spotted Sucker
Spotted Sucker occurrences map


This freshwater fish grows to an average length of 22 to 38 centimetres and can weigh up to 1.3 kilograms. It has distinctive square, brown-black spots on the base of each scale. These are more conspicuous on the sides of the body, appearing as eight to 10 rows of spots along the body. The sides are mostly bronze, coppery or silvery with white or silver undersides. The dorsal, caudal and anal fins are olive grey and other fins are dusky to white.

Action we are taking:


The Spotted Sucker range is restricted to the fresh waters of eastern and central North America from the lower Great Lakes east to Pennsylvania, south to the Gulf Coast and Florida, and west to Texas. In Canada, this species is limited to southwestern Ontario, where it is found in Lake St. Clair and western Lake Erie as well as the Detroit, St. Clair, Sydenham and Thames rivers.


The Spotted Sucker usually inhabits clear creeks and small to moderate sized rivers with sand, gravel or hard-clay bottoms, usually free of silt. However, in Ontario it has frequently been found in turbid habitats. In late spring and early summer, Spotted Suckers move to rocky riffle areas of streams to breed.


Habitat degradation, pollution, siltation and dams are detrimental to the well being of the Spotted Sucker. The Ontario population represents the northern limits for the species so it may always have been rare here.


The Spotted Sucker 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 Spotted Sucker

  • The Ministry of Natural Resources tracks species at risk such as the Spotted Sucker. 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?

Spotted Sucker was not observed in Canada until 1962, when it was captured by a commerical fisherman in Lake St. Clair.

Did you know?

Young Spotted Suckers do not have the distinctive spotting pattern, making it difficult to distinguish from White Suckers and similar redhorse species.

Did you know?

The Spotted Sucker has no teeth in its mouth, but rather has comb-like teeth in its throat (as do most sucker species), which it uses to feed on molluscs and immature aquatic insects.

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.