Species At Risk

Shortjaw Cisco

(Coregonus zenithicus)


Shortjaw Cisco
Shortjaw Cisco occurrences map


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.


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.


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.


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.


The Shortjaw Cisco is protected under Ontario’s Endangered Species Act.

What You Can Do to Help the Shortjaw Cisco

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

Did you know?

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.

Did you know?

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.

Did you know?

When it was more common, the Shortjaw Cisco was likely an important food source for fish predators such as Lake Trout and Burbot.

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.