Whale sharks are fish, not mammals. According to an article by Jennifer Kennedy on About.com, the whale sharks are the largest fish in the world. They grow as long as 65 feet and weigh up to 75,000 pounds. Female whale sharks are generally larger than males.
Whale sharks have skeletons made of cartilage rather than bone, says Kennedy. They mainly eat plankton. Whale sharks live in the warmer portions of the Atlantic, Pacific and Indian Oceans and are capable of migrating over thousands of miles.
Kennedy explains that whale sharks reproduce by laying eggs that develop inside the mother's body, and several litters can result from a single mating. These pups are 2 feet long at birth.