California Aquatic Invasive Species (AIS)
University of California
California Aquatic Invasive Species (AIS)

Invasive Fish Species

Northern Pike

Scientific Name

Esox lucius - Visit ITIS or full scientific classification. 


  • Freshwater fish with a cylindrical body shape and large, flattened snouts.
  • Their snouts are half the length of their heads, and full of sharp teeth.
  • Dark olive, or gray color on their backs and sides, with a white to yellow belly.
  • The adults have rows of pale, oval spots that run along the length of their bodies, while the juveniles have rows of wavy lines.
  • Northern Pike feed primarily on other fish, but will also feed on frogs, snakes, mammals, and birds.
  • Possible for individuals to reach about 3 and a half feet long, and about 30 pounds. 
  • Mostly found in shallow areas of cool lakes, slow running streams, and the backwaters of rivers with plenty of vegetation.
  • Young fish hide within vegetation, and larger adults are found near the edge ready to ambush their prey.
  • Northern Pikes can tolerate extreme environmental conditions including: low oxygen levels, brackish water, and a wide range of temperatures. 
Invasion Pathways and Distribution
  • Northern Pikes are used as game fish, and have been introduced both legally and illegally to many areas across the U.S. for the purposes of establishing sport fisheries.
  • Native to the Great Lakes and surrounding states. See USGS for current U.S. distribution. 
Life History
  • Mating season is February through April, when the water temperature is around 40-65 degrees F.
  • Spawning usually occurs in shallow areas with dense vegetation. 
  • These aggressive top predators eat a variety of different animals but feed primarily on other fishes.
  • They can alter food webs, decrease the number of native fishes, and lower overall species diversity. 
References and Useful Links

For references by category and links to other useful AIS sites see our LEARN MORE page.

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