I just found a strange small ptch of dark circles on my blonde naso. The patch is maybe a half inch by a half inch, on only one side, way up just under the dorsal fin, front third of the tang body. Maybe 5 or sox circles sort of, lighter in the middle. Well above the lateral line. Thought it might be an injury until I looked closer. No google images of diseases look even remotely similar. Any ideas what the heck that is? Fish seems fine.