By Linda Tucker

Background Information Myxobolus 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

Effects on Fish Only 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 Populations Wild 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 Wild Wash 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 Hatcheries Only 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?