Lot's of good information here. I suppose it is likely the Wilds were infected by my domesticated discus. I broke many rules, one was keeping Wilds and Domestics together. I don't remember the pathologist name I was dealing with but she spoke at one of the NADA shows. According to her most tropical she tested 11 years ago had Crypto. That kinda took the fun out of it for me! I expect a lot more has been discovered about crypto, but the pathologist I was working with said crypto was often found to infect the brain. I think that is why we suspected crypto was the culprit. I found this article. https://edis.ifas.ufl.edu/publication/VM077