emperor angel with a whitish coating

[twerksomtin]

This guy I know has an adult emperor angel that looks like it has a whitish coating all over, besides that its eating well and seems healthy. Is this normal, if not, can it be cured?

 

[flameangel88]

Do you know how long the angel has this? If it's velvet it would only take couple of days to take over and the fish will die if untreated quickly.