Threadfin butterfly, ich, or something else?

Question

My threadfin butterfly has white spots at the very tip of his tail, and top of his fin only. He is eating normally, and is not exhibiting an unusual behavior. I started running a UV sterilizer last night. I can't decide if I should setup a hospital tank (I have inverts, so can't treat for ich in the main tank). Is this ich, or possibly something else? How long can I 'wait and see'?

Answer 1

Hard to answer your question without being able to see the spots. This could be ich, or velvet, lymphocystis, fungus, or something else entirely.

I would recommend setting up a hospital tank, although if this is ich, all the fish would need to be moved to be completely safe - only one stage of the parasite occurs on the fish, the rest are in the water, so it's possible another fish may be come infected. If it's something else, the longer you "wait and see" what it might be, the more chance it has to spread to the others if it's infectious.

Since only you can see the fish, I'm posting a link to two of the better resources for diseases for marine fish. In the first, if you see anything that resembles what your fish has, click on the name in red, and it will open a new page with more details, including how to treat that condition.