Next time you visit the Aquarium, be sure to stop by the new Sea of Cortez exhibit on the first level. When you get there, you might see this fascinating behavior--spinning gold-rimmed tangs (Acanthurus nigricans). Here's what it looks like.
This can go on for much longer than the length of this video. This is a common territorial interaction for several species of surgeonfish.
Be sure to look for other fascinating fish behaviors during your visit to the tropical gallery.