A silvery whitefish relative critical to Great Lakes food webs as forage for lake trout and salmon. Crashed in the 1900s from sea lamprey and overfishing; recovering.

Also called: Lake Herring, Cisco

Native status: Native to Great Lakes and northern North America

§ Quick facts

SizeLength 25–50 cm
Weight200–700 g
LifespanWild 8–13 years
OrderSalmoniformes
FamilySalmonidae

§ Encyclopedia

Cisco Systems, Inc., doing business as Cisco, is an American multinational technology conglomerate corporation that develops, manufactures, and sells hardware, software, telecommunications equipment and other high-technology services and products focused on networking, cyber security and AI. Cisco specializes in specific tech markets, such as the Internet of things (IoT), domain security, videoconferencing, and energy management, including products such as Webex, OpenDNS, Jabber, and Jasper. The company is headquartered in San Jose, California, and, as of December 2025, has a market capitalization of $317 billion.

Source: Wikipedia — Cisco Licensed under CC BY-SA 4.0

§ Identification

Field marks. Slim silvery fish with deeply forked tail; small adipose fin; large eyes.

Similar species. Other coregonid species. Lake Whitefish (deeper-bodied).

Voice. Silent.

§ Diet & behavior

Diet. Zooplankton, small fish.

Behavior. Once abundant in Great Lakes, supporting major commercial fishery. Multiple distinct ecological races ("morphotypes") existed in deep waters; most are now extinct, devastated by overfishing, sea lamprey predation, and competition from invasive alewife and smelt. Lake Superior population remains relatively healthy; tribal-state-federal restoration projects target other Great Lakes.

§ Range

Northern North American lakes

§ Habitat

Cold lakes, especially Great Lakes and Canadian boreal

§ Threats

Sea lamprey predation, climate-driven warming, invasive species altering food webs.

§ Conservation status

According to the IUCN Red List, the cisco (lake herring) is currently classified as Least Concern.

§ What helps

Support Great Lakes restoration. Buy native commercial cisco where available.

Support our work More ways to help

§ Further reading

§ Sources cited

  • Great Lakes Fishery Commission
  • Wisconsin DNR
  • NatureServe
  • IUCN Red List 2014