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Invasive Species: Rudd


(Scardinius erythrophthalmus)
*Established in Michigan*


Report this species:

Use the Midwest Invasive Species Information Network (MISIN) online reporting tool.

- Or - download the MISIN smartphone app and report from your phone -



  • Deep and stocky body with green-brown back, brassy yellow sides, and near white belly.
  • Lengths can reach 48 cm.
  • Pectoral, pelvic, and anal fins are bright red-orange.
  • Dorsal and caudal (tail) fins are red-brown.
  • Caudal fin is forked and lower lip is protruding.
  • Red spot on iris of the eye.

Photo courtesy of U.S. Geological Survey,

Photo courtesy of John Lyons.

Habitat: Preference is given to stagnant and slow-flowing freshwater with a lot of vegetation, but rudd are adaptable.

Diet: Rudd are omnivorous fish. Their diet consists primarily of fish in the early spring and changes to mostly vegetation in the summer and fall.

Native Range: From Western Europe to the Caspian and Aral Sea basins.

U.S. Distribution: Rudd have been introduced to 20 U.S. states and has been used as a bait fish in many of the others.

Local Concern: Although the impacts of introduction are largely unknown, the rudd’s ability to shift its diet as necessary, and its tolerance of eutrophic or polluted waters gives it an advantage over native species. Another ecological impact comes from an increase in nutrients in the water due to the rudd ineffectively processing plant material.

Native look-alikes and how you can tell them apart from a rudd:

  • Golden Shiner: Unscaled ventral keel, yellow-green eyes, yellow-green fins (except in spawning adults).
  • Redfin Shiner: No ventral keel, fins typically clear except in breeding males, small dark spot at anterior base of the dorsal fin.


Rudd Invasive Species Alert (printable PDF)