Whirling disease caused by Myxobolus cerebralis is a scourge for fish culturists and salmonid biologists, and rumors have circulated for decades that its myxospores remain viable for years. Nehring et al. (2015) used a carefully designed time-delay study that exposed susceptible oligochaetes to myxospores and then measured production of actinospores as evidence of myxospore viability. This jounal review originally appeared in the May 2015 issue of Fisheries magazine