Sounds like velvet or brooklynella. Wild caught clowns are especially prone to brook. Check out wetwebmedia I am not sure what the best course of treatment is but good luck and I hope you have a successful outcome.
if it is brook, there is like a 90% chance of it dying, it is very common in wild caught clowns, not much you can do. If it is something else, I just hope that you QT.
I did some reading and it was clownfish disease. I read about it in a book I have. He died shortly after. I cleaned out my FW 10 gallon tank which I will make a QT tank.
Im sorry you lost your second clown. QTing prior to addiing to the display tank may be in order in the future to prevent possible illness being brought into the tank.
