Response of rainbow trout Oncorhynchus mykiss to exposure to Myxobolus cerebralis above and below a point source of infectivity in the upper Colorado River

We exposed 9 wk old rainbow trout Oncorhynchus mykiss to ambient levels of Myxobolus cerebralis infectious stages at 4 sites of suspected differing infectivity in the Colorado River. Exposure was estimated by periodic filtration of river water at each exposure location. After a 32 d exposure, the fish were held in the Colorado River at a common site for over a year. Resulting infection was evaluated by the presence of clinical signs (whirling behavior, cranial deformity/exophthalmia, and black tail), severity of microscopic lesions, and myxospore counts (8, 10, 12, and 14 mo post-exposure). Two exposure sites that were immediately downstream of Windy Gap Reservoir were much higher in infectivity than the site above...

Categories: Publication; Types: Citation, Journal Citation; Tags: Diseases of Aquatic Organisms, Myxobolus cerebralis, Rainbow trout, Whirling disease