My son recently went on a cub scout fishing trip to a local lake and brought home his catch, a small bluegill. I've kept natives before so this wasn't a big deal. The next morning I noticed a white growth on the dorsal and right pectoral fins. They have grown a little in the last couple of days. I've checked my water quality and it is fine. I've never had any issues with fungus or any other fish diseases in my tanks (knock on wood). Is this something that could spread to other fish? Is is treatable?
It has settled in nicely and has become friends with the convict that I have in the tank. They pal around together and hide in the same spots. It's almost like he taught the new guy what he needs to know. He is eating well already. Other natives that I've had took about a week before they would eat. My son would be devastated if we had to get rid of him. Thoughts?

It has settled in nicely and has become friends with the convict that I have in the tank. They pal around together and hide in the same spots. It's almost like he taught the new guy what he needs to know. He is eating well already. Other natives that I've had took about a week before they would eat. My son would be devastated if we had to get rid of him. Thoughts?
