You're absolutely right that many animals can do that (hibernate, form spores, go dormant), but ich just isn't one of them. It's being studied constantly because of it's cost to fisheries. In fact, it's genome has been sequence, iirc, so it'd be quite a scientific blockbuster if it could do what almost nobody thinks it can do. I've looked and there are no studies or scientists claiming this protozoan has a dormant stage, whereas there are many that state clearly that it doesn't.
Ich doesn't survive very long under tropical temps without a host (of course, it can do so for weeks at low temps) and it doesn't survive outside of water.
Ich doesn't survive very long under tropical temps without a host (of course, it can do so for weeks at low temps) and it doesn't survive outside of water.