Whirling Disease Wildlife and Fisheries Paul Dunay

Background ● Caused by microscopic parasite called Myxobolus cerebralis ● Affects trout and salmon; not humans or warm water fish ● Primarily affects juveniles ● Characterized by whirling motions during swimming ● Introduced to U.S in 1950 from Europe; Found in 25 states

Life Cycle ● Two-host life cycle ● Infected fish dies; spores are released ● Ingested by the tubifex worm ● Infects susceptible fish by attaching to their bodies, or when fish eat infected worms.

Symptoms ● Blackened tail ● Spinal deformities ● Uncontrollable whirling

Prevention ● Wash off mud from boats, vehicles, equipment ● Hatcheries use ultraviolet rays to kill parasites ● Do not dispose fish entrails in any body of water ● Do not displace fish in other bodies of water

Works Cited Colorado Division of Wildlife Whirling Disease Initiative