Guiana dolphins may seem like simple, playful creatures, but when you look into their past, things get pretty hairy - literally. That's because these dolphins are born with whiskers on their snouts! These whiskers fall off eventually, but the pits that these whiskers were once anchored to (called vibrissal crypts) are used to sense the electric fields emitted by prey. Like the shark, the receptors in a Guiana dolphin's snout also have a kind of gel that allows him to detect the presence of possible food. Each crypt is surrounded by blood vessels and connected to the trigeminal nerve, a special nerve that carries sensory information to the dolphin's brain.
12. Electric eels