Whirling DiseaseBy Linda Tucker

Background InformationMyxobolus cerebralis

Native to Europe and first described in 1903

Currently found in Europe, United States, northern Asia, New Zealand, Morocco, Lebanon, and South Africa

First confirmed in the United States in 1958 in Pennsylvania

Has spread to 25 states

Life Cycle of M. cerebralis

Life Cycle of M. cerebralis

Life Cycle of M. cerebralis

Life Cycle of M. cerebralis

Effects on FishOnly affects salmonid species

Younger fish are more susceptible than older fish

Rainbow Trout is the most susceptible species

Symptoms include skeletal deformities, black tails, and whirling behavior

Can slow growth and increase mortality

Spinal Deformity and Black Tail

Head Deformity

Whirling Behavior

Impacts on Wild PopulationsWild populations declined in Western U.S.

Eastern and western coastal populations stable

Decline of single trout species can lead to community composition changes

Food web affected

Impacts on Fish Hatcheries

Destruction of infected fish

Disinfection and renovation of facilities

Closure of some facilities

Money lost and money spent

Prevention in the WildWash and dry all equipment when moving

between bodies of water

Don’t transfer live fish from one place to another

Dispose of unused bait in the trash

Never discard fish parts near the water

Prevention in Fish HatcheriesOnly use groundwater sources for water

Purchase fish that are certified to be whirling disease free

Line raceways with concrete

Frequently clean solids from settling areas

Treatment

There is no treatment for infected fish

Remove infected fish

Disinfect

Follow prevention methods to avoid reintroduction

Questions?