Is anilocra gigantea the tongue-eating isopod? I hope that's not it.
Seems like to get a definitive id, I will need to catch the villain. It fell off when I started trying to net the fish, so I will need to find a gentler way to capture the host. I did see an article in the past that suggests a way to trap these after lights out, so I will give that a try too.
Please keep the ideas coming! This is a new 220g tank, has had nothing in it except the live rock/sand I used to seed the tank, so whatever it is came in on that stuff. Since I only have these two fish in the tank, I can get them out easily if I need to treat the tank. The problem will likely be that I am betting that any treatment options I have will also nuke all of the other beneficial stuff in the tank, right?