I've got a fancy male guppy that seems to have been sick for more than a week now. He has been having some trouble swimming and sometimes sits along the bottom. He is still eating and spends most of his time swimming. This morning I noticed he has what looked like a small growth that was fuzzy or furry looking. I just looked at him now and that is gone but there seems to be a string-looking thing coming from the same area just behind his right fin. Any ideas on what this could be?