Regal or Hippo Tang
This beautiful fish is prone to diseases, but after an initial period with white spots on it, it recovered, and has been fine. I try not to introduce any specimens into the tank which have not been well in another tank for less than 2 weeks. I keep cleaner shrimp in the reef tank, hoping that this too will help. An algae eater, I try to provide fresh macro algae regularly, along with flake food. In the background you can see a giant clam (left) and a green elegance coral (right).
Fish change colors at night, becoming less colorful so that they can hide better. Right after a fish wakes up, it often has a mottled appearance, and this can alarm the novice aquarist. Here is the tang with some morning white spots on it. The picture below shows the same fish from the other side, demonstrating that this was not a photographic accident.