Portals of entry for salmonid whirling disease in rainbow trout

Portals of entry via the skln, fins, buccal cavlty and dlgestlve tract have been demonstrated for the myxozoan that causes salmonld whirling disease Exper~mentally, young rainbow trout Salmo ga~rdner~ were evposed to tnactlnomyxon spores W~thin 10 nun after ~nitial exposure intracellular aggregates of trlactinomyxon sporoplasms appeared in the e p ~t h e h a of exposed fish Dunng several hours following penetrat~on, the sporoplasms moved or were trdnsported from the external ep~thelial layers into deeper strata Unexposed control trout were free of the organlsm The aggregates of intracellular triactinomyxon sporoplasms were idenufied serologically as belng Myxobolus cerebrahs