From their origin more than 400 million years ago, sharks have evolved in many directions. One of the most interesting and unusual species is the whale shark, named for its enormous size and its behavioral similarity to some whales.
Whale sharks defy the stereotypical image of sharks as ferocious hunters.
Instead, these gentle giants are filter feeders that feast on swarms of tiny, floating animals called zooplankton. Though the massive jaws are equipped with thousands of tiny teeth, whale sharks neither bite nor chew their food. To feed, the shark cruises slowly near the ocean surface with its mouth wide open, or orients its body vertically below the surface and sucks in vast volumes of water. Originally thought to be so different from other sharks that it was classified in a family of its own, recent studies place the whale shark in the same family as zebra and nurse sharks, based on their anatomical similarities. This family, together with four other families of carpet sharks and wobbegongs, constitutes one of the eight orders of living sharks called the Orectolobiformes.