“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 Shortjaw Cisco was already assessed as threatened when the Endangered Species Act took effect in 2008.

What it looks like

The Shortjaw Cisco is a member of the whitefish family. It can grow up to 40 centimetres long and weigh up to one kilogram. It has an olive-tan to greenish back, silvery-coloured sides, a purple sheen and a white belly. The Shortjaw Cisco has large eyes, a small head, a very small mouth with no teeth, and a small lower jaw.

Where it lives

The Shortjaw Cisco spends most of the year in deep water, usually between 55 to 180 metres in depth. During the breeding season, which can be spring or fall depending on the lake, it migrates to shallower water (10 to 60 metres) to mate and lay eggs. It feeds on tiny aquatic animals, called zooplankton, but also eats aquatic insects, crustaceans, and freshwater shrimp.

Where it’s been found in Ontario

The Shortjaw Cisco lives in the Great Lakes, and a few large lakes in Ontario, Manitoba, Saskatchewan, Alberta and North West Territories. In Ontario, it is found in Lake Superior, Lake Nipigon and in some smaller inland lakes. It is considered extirpated from lakes Michigan, Erie and Huron.

map of shortjaw cisco range

View a larger version of this map (PDF)

What threatens it

Ontario’s Shortjaw Cisco population was greatly reduced by overfishing in the Great Lakes and possibly by competition or predation by exotic (non-native) species.

Action we are taking

Threatened species and their general habitat are automatically protected.

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

Report illegal activity

  • Report any illegal activity related to plants and wildlife to 1-877-TIPS-MNR (847-7667).

Quick facts

  • The Shortjaw Cisco, also known chub, was an important part of Ontario’s smoked fish industry until the 1950s when this fish and other cisco fish species became too rare and hard to find.
  • The Shortjaw Cisco can be very hard to identify because of its similarity to other cisco species. Its appearance can also vary depending on the lake it lives in.
  • When it was more common, the Shortjaw Cisco was likely an important food source for fish predators such as Lake Trout and Burbot.