Whale Sharks

Image: Brian Skerry, Smithsonian Magazine.

Check out the world's largest fish, the whale shark, which can reach lengths of more than 45 feet! These fish were featured in a recent article from Smithsonian Magazine. You would think the diver would be afraid of being eaten by the "shark", but it turns out these filter-feeders prefer zooplankton, which is how they got their name. Look, no teeth:

How is it the largest animals seem to thrive off the smallest creatures? By eating all day. In fact, a recent study of these animals shows that they spend 7.5 hours per day feeding on the tiny creatures. By their calculations, a 443cm whale shark could eat 1467g of plankton per hour.

I once had a dog that ate all day like that. We called him Hoover.

Source:
Motta PJ, Maslanka M, Hueter RE, Davis RL, de la Parra R, Mulvany SL, Habegger ML, Strother JA, Mara KR, Gardiner JM, Tyminski JP, Zeigler LD. Feeding anatomy, filter-feeding rate, and diet of whale sharks Rhincodon typus during surface ram filter feeding off the Yucatan Peninsula, Mexico. Zoology(Jena). 2010 Aug;113(4):199-212.