For absolute emergencies only
Suddenly, my Atlantic/Caribbean Blue Tang came down with a bunch of brown marks. They are not round, but irregular shapes. The skin is a little inflamed around each of the marks. They are on both sides of the fish, but more on the side shown below. So far, his appetite and general demeanor are unchanged.
A friend provided me this link to common fish diseases: http://www.chucksaddiction.com/disease.html To me, it would appear to be the first "ailment"