Since I can't post links here is a quote from another person on a different site;
"Thanks greenbean36191. Are you referring to his 1997 or earlier work or something more recent.
One of his studies showed that the cyst lived in (I believe) 15ppt saline water and delayed producing Theronts for 28 days. However, the Theronts died at that ppt.
There are two stages of the Cryptocaryon irritans cycle that is affected by hyposalinity: Theronts and the encysted Tomonts. Each are susceptible to hyposalinity, but at different salinities, and in different ways. The most susceptible are the free swimming Theronts and they still die at hyposaline treatment levels. The cysts have been varying and some, though not killed, just delay their release of the Theronts (which do die).
Much of Colorni's work was on the cysts since at that time, it was thought that the cysts were the ones to attack and kill in any treatment process.
In the '70's when I worked on finding means to eradicate Marine Ich, the best approach was to attack the Theronts. Later that switched to the cysts. Now it's back to the Theronts.
Last year, which was a few months after I had heard the Asian rumors, I spoke in person with Dr. Edward Noga and a few other Veterinarian staff members of NCSU. At that time they too have not heard of any Theronts surviving hyposaline treatment.
To the best of my knowledge no one has showed Theronts capable of surviving low salinity. But there are always rumors and explanations on why the Marine Ich shows up after a hyposaline treatment. They often fall back on early work with cysts.
I meet with Dr. Noga in a few weeks. If you have any recent paper that might suggest otherwise to the above, I'd appreciate you providing the reference. I'd like to bring it to Dr. Noga's attention."
maybe it is a time frame issue and not wether they will die or not.