Cover photo credit: New York State Department of Environmental Conservation



“Threatened” means the species lives in the wild in Ontario, is not endangered, but is likely to become endangered if steps are not taken to address factors threatening it.

Date added to the Species at Risk in Ontario List

The Lake Chubsucker was already assessed as threatened when the Endangered Species Act took effect in 2008.

What it looks like

The Lake Chubsucker is a small member of the sucker family that reaches about 25 centimetres in length. It has a deep body with an arched back, a rounded snout, and a downward facing small sucker mouth. Its back is dark olive to greenish-bronze and the belly is green-yellow to yellow-white. There is sometimes a dark stripe along the side of the body that extends from the tail to the snout. This stripe is especially obvious in young fish.

Where it lives

In Ontario, the Lake Chubsucker lives in marshes and lakes with clear, still, warmer water and plenty of aquatic plants. This habitat is found in bays, channels, ponds, and coastal wetlands. During the breeding season, from April to early June in Ontario, adults move into marshes where eggs are laid among vegetation in shallower water. The chubsucker eats algae, plankton, molluscs, and aquatic insects.

Where it’s been found in Ontario

In Canada, the Lake Chubsucker is found at several sites in the Ausable River, Lake St. Clair, Lake Erie and the Niagara river drainage in southern Ontario.

map of lake chubsucker range

View a larger version of this map (PDF)

What threatens it

The main threat to the Lake Chubsucker is habitat destruction due to wetland drainage and too much sediment in the water. This species likes clean, clear water and does not do well in waters that are muddy or polluted. Water can become muddy due to soil washing in from nearby urban and agricultural areas.

Action we are taking

Threatened species and their general habitat are automatically protected.

Recovery strategy

A recovery strategy advises the ministry on ways to ensure healthy numbers of the species return to Ontario.

Read the executive summary and recovery strategy (June 15, 2012).

Government response statement

A government response statement outlines the actions the government intends to take or support to help recover the species.

Read the government response statement (May 31, 2013).

Five-year review of progress

A five-year review of progress made toward protecting and recovering a species is required no later than five years after the government response statement for that species is published.

Read the report on progress towards the protection and recovery of 17 species at risk, including the Lake Chubsucker (2018).

Habitat protection

General habitat protection - June 30, 2013

What you can do

Report a sighting

Report a sighting of an endangered animal or plant to the Natural Heritage Information Centre. Photographs with specific locations or mapping coordinates are always helpful.


Volunteer with your local nature club or provincial park to participate in surveys or stewardship work focused on species at risk.

Be a good steward

  • private land owners have a very important role to play in species recovery; if you find a nesting on your land, you may be eligible for stewardship programs that support the protection and recovery of species at risk and their habitats
  • 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:
  • 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 rivers; you can find more information about programs and funding assistance for eligible farmers from the Ontario Soil and Crop Improvement Association website at

Report illegal activity

Report any illegal activity related to plants and wildlife to 1-877-TIPSMNR (8477667).

Quick facts

  • the scales on the upper half of the Lake Chubsucker are darkly outlined, which makes it look like the body of the fish has been crosshatched
  • researchers know very little about the life history or biology of this species. It can be very hard to find this secretive fish, which lives in areas of dense aquatic vegetation
  • the presence of the Lake Chubsucker is a good indicator of healthy wetland habitats