Northern Sunfish
(Lepomis peltastes)
Status: Special Concern: Great Lakes - Upper St. Lawrence Population (ESA 2017, COSEWIC 2016)
Species Identification:
The Northern Sunfish is a small member of the sunfish family at about 13 cm long. They are a very thin fish with olive colouring, and bright red and blue patterned scales. Their belly is bright yellow, and their fins also have bright red and blue colouring. Females can grow slightly larger than males.
Diet:
This species is mainly insectivorous, picking mature and immature aquatic insects off of plants and out of the water. As adults, they will also feed on small fish and fish eggs of other species.
Habitat and Range:
The Northern Sunfish can be found across north-eastern North America. In the United States, Northern Sunfish are found in northern Ohio, Indiana, northeastern Illinois, the lower peninsula of Michigan, and eastern Wisconsin. There are also small scattered populations in Minnesota, western Wisconsin, and southern Illinois. In Canada, the population is restricted to southern Quebec and Ontario. The Canadian populations can be separated into two distinct groups: The Saskatchewan - Nelson River Population and the Great Lakes - Upper St. Lawrence Population. The Saskatchewan - Nelson River Population occurs in northwestern Ontario and is considered Not at Risk, whereas the Great Lakes - Upper St. Lawrence Population can be found in southern and eastern Ontario as well as southern Quebec, and is listed as Special Concern. The Northern Sunfish can be found in the Georgian Bay tributaries, as well as the Trent River systems.
Northern Sunfish prefer shallow areas of lakes, rivers, and ponds with very little current. They prefer sandy or rocky bottoms with plenty of vegetation to hide in, as well as protection from strong currents. Northern Sunfish also need relatively clear water, and they cannot tolerate high amounts of turbidity (cloudy water) or silt.
Biology and Behaviour:
In Canada, Northern Sunfish begin spawning in June or July, close to their regular habitat. Like all sunfish species, the male will arrive first and begin making a circular nest in the sand or gravel bottom. He will guard his nest from other males in the area, only allowing females near. Some females will lay all of their eggs in one male’s nest, and others will spread them out between a few males. There are also some males called “sneaker males”, who will not make their own nest, but sneak up to other nests and fertilize some of the eggs before the nest male notices. Females can lay between 1,000 and 4,300 eggs each season. Eggs are about 1 mm in diameter and they are fertilized and then guarded by the male until they hatch in 3-5 days. The male will continue to keep an eye on the hatchlings until the yolk sacs have been consumed and they are ready to leave the nest. Northern Sunfish reach sexual maturity at 3-4 years, and they can reach ages of up to 4-7 years. Predators of the Northern Sunfish are birds and predatory fish, especially Bass species.
Similar Species:
The Northern Sunfish is a typical looking sunfish, so it is often confused with the Longear Sunfish and the Pumpkinseed. Only experts can tell these species apart by looking at their ear flaps. The Northern Sunfish has an ear flap that is angled upwards and has red and orange colouring.
Conservation and recovery strategies:
Northern Sunfish are only listed as Special Concern, so they are not directly protected and there are no conservation or recovery strategies currently in place. They are, however, still protected under the Federal Fisheries Act and are subject to possession limits. Their habitat may be indirectly protected by other nearby Species at Risk, and many water bodies are protected from development Conservation Authorities Act, Provincial Planning Act, Canadian Environmental Assessment Act, and Water Resources Act.
Additional Resources:
- Government of Ontario Northern Sunfish Species at Risk page
- Northern Sunfish information page from iNaturalist
- COSEWIC 2016 Assessment and Report on the Northern Sunfish
Sources:
COSEWIC. 2016. COSEWIC assessment and status report on the Northern Sunfish Lepomis peltastes, Saskatchewan - Nelson River populations and the Great Lakes - Upper St. Lawrence populations, in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. xv + 51 pp. https://wildlife-species.canada.ca/species-risk-registry/virtual_sara/files/cosewic/sr_Northern%20Sunfish_2016_e.pdf
Government of Ontario. 2017. Northern Sunfish. Retrieved from: https://www.ontario.ca/page/northern-sunfish
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