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Coregonus artedi

What do they look like?

Ciscoes have a long body, with a length of about 267 mm. These fish are silvery and their dorsal fins have around 9 to 11 rays and their scales are moderately sized. Their lower jaw is either shorter than, or the same length as their upper jaw, and they have two flaps between their nostrils. It can be difficult to identifying ciscoes because they look so similar to other related species. ("Distribution and abundance of the lake herring (Coregonus artedi) in Michigan", 1995; "Lake Herring, Coregonus artedi", 2014; Bailey, et al., 2004; Becker, 1983; Koelz, 1929)

  • Range mass
    3.4 (high) kg
    7.49 (high) lb
  • Range length
    17 to 40 cm
    6.69 to 15.75 in

Where do they live?

Ciscoes (Coregonus artedi) are found in North America, throughout Canada and the northern United States, specifically in the St. Lawrence Seaway and the Great Lakes. In a north-south direction, ciscoes range from the upper Mississippi drainage in the United States to the Northwest Territories and Alberta in Canada. Ciscoes are found throughout the Great Lakes. In Michigan, ciscoes in inland lakes are mostly found in southern parts of the state, from Oakland County, south to Cass County. Lake Superior is the only lake where there is a large population of ciscoes; lakes Erie, Michigan, Ontario, and Huron have smaller populations. In Wisconsin, their populations are mostly found in northern waters, including the Mississippi River, Lake Michigan, and Lake Superior drainage basins. Ciscoes are common in Wisconsin’s northern inland lakes but are rare in Madison-area lakes. ("Distribution and abundance of the lake herring (Coregonus artedi) in Michigan", 1995; "Lake Herring, Coregonus artedi", 2014; Becker, 1983; Luna, 2014; Todd and Smith, 2011)

What kind of habitat do they need?

Ciscoes are found near the bottom of cold-water Great Lakes and inland lake environments. During the winter months, they move into shallow coastal waters to spawn, but then return to deeper waters in the spring. Ciscoes are rarely found in waters above 17 to 18ºC. They can live in lakes with surface areas ranging from 20 to 19,000 acres, but are mostly found in lakes with an average surface area of 100 acres and depths of at least 10 m. Ciscoes are often found in lakes with low nutrients. ("Distribution and abundance of the lake herring (Coregonus artedi) in Michigan", 1995; "Lake Herring, Coregonus artedi", 2014; Becker, 1983; Wells, 1968)

  • These animals are found in the following types of habitat
  • freshwater
  • Aquatic Biomes
  • pelagic
  • lakes and ponds
  • Range depth
    27 to 46 m
    88.58 to 150.92 ft

How do they grow?

Since ciscoes spawn in the winter, their eggs develop slowly and hatch in the spring as ice begins to thaw. Young ciscoes usually live in shallow bays until they are around one month old, and usually mature within 1 to 4 years. ("Lake Herring, Coregonus artedi", 2014; Becker, 1983)

How do they reproduce?

Ciscoes form a group for spawning as temperatures decrease in the fall. Males usually arrive at the spawning grounds before females and are also the first ones to leave. ("Lake Herring, Coregonus artedi", 2014)

Ciscoes usually spawn in late November to mid-December in near-shore waters that are around 5 to 6ºC. Their rate of spawning usually increases when temperatures fall below 4ºC. Eggs are deposited at night on top of rocky areas. While spawning, ciscoes can be seen jumping and splashing. (Becker, 1983)

  • How often does reproduction occur?
    Ciscoes breed once a year.
  • Breeding season
    These fish breed in the winter, from late November to mid-December.
  • Range time to hatching
    5 to 6 months
  • Range age at sexual or reproductive maturity (female)
    1 to 4 years
  • Range age at sexual or reproductive maturity (male)
    1 to 4 years

After eggs are deposited in near-shore environments, they are abandoned by the parents. ("Lake Herring, Coregonus artedi", 2014)

  • Parental Investment
  • no parental involvement

How long do they live?

Ciscoes have an average lifespan of 6 to 10 years, with a maximum age of 13 years. Interestingly, their scales may be used to estimate their age. ("Lake Herring, Coregonus artedi", 2014; Scott and Crossman, 1998)

  • Range lifespan
    Status: wild
    13 (high) years
  • Typical lifespan
    Status: wild
    6 to 10 years

How do they behave?

Ciscoes move constantly. These fish form schools during the day and separate at night. Schools are usually around 1 to 2.3 meters tall and form in lower light areas, where their main predator, lake trout cannot see them. Ciscoes usually have fuller stomachs during the daytime. Likewise, stomach fullness increases with school size, which suggests schooling helps protect these fish from predators and helps them forage. ("Lake Herring, Coregonus artedi", 2014; Milne, et al., 2005)

Home Range

Ciscoes usually live their entire life within a few kilometers of where they hatched, though in some cases, individuals may travel about 81 km from where they hatched. (Becker, 1983; Smith and Van Oosten, 1940)

How do they communicate with each other?

Not very much is known about how ciscoes communicate. Because these fish are very social and move as a school, they likely have several ways of communicating with each other.

What do they eat?

When the waters they live in freeze over, ciscoes can feed under the ice at night. They usually eat algae and small crustaceans (Cladocera, Copepoda, and Mysis). Sometimes these fish also eat mollusks, insect larvae, and small fish. Young ciscoes usually need light to find their prey and mainly eat algae and zooplankton, while adults mostly eat crustaceans and aquatic insects. ("Lake Herring, Coregonus artedi", 2014)

  • Animal Foods
  • eggs
  • insects
  • mollusks
  • echinoderms
  • other marine invertebrates
  • zooplankton
  • Plant Foods
  • algae

What eats them and how do they avoid being eaten?

Ciscoes mostly avoid predators by schooling. Their main predators include lake trout, northern pike, yellow perch, walleye, sea lamprey, rainbow trout, and burbot. ("Lake Herring, Coregonus artedi", 2014; Anderson and Smith, 1971)

What roles do they have in the ecosystem?

Ciscoes play a big role in the Great Lakes ecosystem, especially as a main food source for lake trout, yellow perch, walleye, and northern pike. However, between 1930 and 1960, over-fishing, pollution, and competition with non-native species like rainbow smelt caused their population to decline. As the numbers of rainbow smelt get bigger in inland lakes, the population of ciscoes goes down and they disappear completely in areas where rainbow smelt eat their young. ("Lake Herring", 2014; "Lake Herring, Coregonus artedi", 2014; Anderson and Smith, 1971; Gunderson, 2004)

Do they cause problems?

There are no known negative impacts of ciscoes on humans.

How do they interact with us?

Historically, ciscoes are one of the most commercially important fish in the Great Lakes; in the 1940s, cisco fisheries were producing around 19 million pounds annually. (Gunderson, 2004)

  • Ways that people benefit from these animals:
  • food

Are they endangered?

Severe over-fishing from 1930 to 1960 and competition with invasive rainbow trout, or other competitors like alewives and bloaters have caused cisco populations to decline. However, rainbow trout populations collapsed in the 1970s, and since that time, ciscoes have been slowly rebounding. Currently, the greatest current threat to ciscoes in the Great Lakes is the addition of nutrients, which eventually cause the amount of oxygen to be reduced, forcing ciscoes into shallower, warmer parts of the water column. These higher temperatures, particularly during the summer months, cause large numbers of the fish to die. Recently, the Michigan Department of Natural Resources has formed a recovery plan for ciscoes in Lake Huron. Since overfishing is no longer a problem, their competition with rainbow smelt and alewives may be keeping cisco populations low. One motivation for restoring cisco populations is to control alewife populations. Alewives prey on the young of economically important lake trout, and it is thought that greater cisco populations will help fix this. (Luna, 2014; "Strategy and Options for Promoting the Rehabilitation of Cisco in Lake Huron", 2007; Anderson and Smith, 1971; Becker, 1983; Madenjian, et al., 2011)


Lucas Joel (author), University of Michigan-Ann Arbor, Jeff Schaeffer (editor), University of Michigan-Ann Arbor, Leila Siciliano Martina (editor), Animal Diversity Web Staff.


Michigan Department of Natural Resources. Distribution and abundance of the lake herring (Coregonus artedi) in Michigan. 2014. Ann Arbor, MI: University of Michigan Library. 1995.

2014. "Lake Herring, Coregonus artedi" (On-line). Michigan Department of Natural Resources. Accessed October 28, 2013 at,4570,7-153-10364_18958-45668--,00.html.

2014. "Lake Herring" (On-line). Monterey Bay Aquarium Seafood Watch. Accessed October 28, 2013 at

Lake Huron Technical Committee. Strategy and Options for Promoting the Rehabilitation of Cisco in Lake Huron. 1. Ann Arbor, MI: Great Lakes Fishery Commission. 2007.

Anderson, E., L. Smith. 1971. Factors affecting abundance of lake herring (Coregonus artedi) in western Lake Superior. Transactions of the American Fisheries Society, 100/4: 691-707.

Bailey, R., W. Latta, G. Smith. 2004. An atlas of Michigan fishes with keys and illustrations for their identification. Miscellaneous publications / University of Michigan, Museum of Zoology, 192: 215.

Becker, G. 1983. Fishes of Wisconsin. Madison, WI: University of Wisconsin Press.

Gunderson, J. 2004. "Cisco: Also Known as Lake Herring" (On-line). SeaGrant. Accessed October 28, 2013 at

Koelz, W. 1929. Coregonid fishes of the Great Lakes. US Bureau of Fisheries, Part II: 297-643.

Luna, S. 2014. "Coregonus artedi Lesueur, 1818" (On-line). FishBase. Accessed October 28, 2013 at

Madenjian, C., E. Rutherford, M. Blouin, B. Sederberg, J. Elliott. 2011. Spawning Habitat Unsuitability: An Impediment to Cisco Rehabilitation in Lake Michigan. North American Journal of Fisheries Management, 31: 905-913.

Milne, S., B. Shuter, W. Sprules. 2005. The schooling and foraging ecology of lake herring (Coregonus artedi) in Lake Opeongo, Ontario, Canada. Canadian Journal of Fisheries and Aquatic Sciences, 62: 1210-1218.

Scott, W., E. Crossman. 1998. Freshwater fishes of Canada. Fisheries Research Board of Canada, Ottawa, 184: 966.

Smith, O., J. Van Oosten. 1940. Tagging experiments with lake trout, whitefish, and other species of fish from Lake Michigan. Transactions of the American Fisheries Society, 69: 63-84.

Todd, T., G. Smith. 2011. Environmental and Genetic Contributions to Morphological Differentiation in Ciscoes (Coregoninae) of the Great Lakes. Canadian Journal of Fisheries and Aquatic Sciences, 39: 261-267.

Wells, L. 1968. Seasonal depth distribution of fish in southeastern Lake Michigan. US Fish and Wildlife Service Fishery Bulletin, 67/1: 1-15.

University of Michigan Museum of ZoologyNational Science Foundation

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Joel, L. 2014. "Coregonus artedi" (On-line), Animal Diversity Web. Accessed April 18, 2024 at

BioKIDS is sponsored in part by the Interagency Education Research Initiative. It is a partnership of the University of Michigan School of Education, University of Michigan Museum of Zoology, and the Detroit Public Schools. This material is based upon work supported by the National Science Foundation under Grant DRL-0628151.
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