My brother gave me a very small wild caught damselfish from south Florida for my new, still cycling nano reef, but the fish developed a small white bump on its back overnight. What is this and how can I treat it? Unfortunately the little guy is very small and very quick, so I only have one good picture of the bump at the time of creating this post. It is the only fish in the tank currently, but there are also hermit crabs and snails in the tank with it. I just added maricultured Florida liverock straight from the gulf two days ago at the same time as the fish so it could easily be a hitchhiker from the rock or from the wild fish. Just please tell me it isn't ich!