The whale shark (tiburon ballena, in Spanish) is the world’s largest fish, reaching lengths of 40 feet or more. Whale sharks have very large mouths and are filter feeders. They feed almost exclusively on plankton and, therefore, despite their size, are completely harmless to humans. They also play friendly host to other fish, such as the remora, or suckerfish, which often hitches a ride. We recently had a unique and amazing opportunity to swim with these creatures in La Paz. Be sure to check out the video!