As stated above, the behind the scenes tours are not yet available. However, there was video playing at the big window, and some of it showed the whale sharks eating. They had several pounds of krill, and other such meaty foods, all in a large scoop/bucket. For some reason, I'm thinking they fed 16.5 lbs at a time, twice a day. Anyway, they put this bucket in front of the shark, and he starts this huge vacuum, sucking in what must be dozens of gallons of water within a couple seconds. The food, of course, gets sucked right in with it. It was quite amazing to see the aquatic "black hole" into the shark's mouth.