For the past 280 to 345 million years, sharks in general have remained relatively unchanged, indicating that they are one of the most successfully adapted creatures in existence. Sharks exist in a wide range of sizes, shapes, colors, behaviors and abilities . They live in frigid Arctic waters, in warm tropical waters close to humans, and far down in the deep seas, where we are still discovering surprising species. Different sharks eat different foods, from tiny plankton to thousand pound elephant seals and sea lions. A few, like the giant whale shark, are docile and easily approached by man, while others like the great white, tiger and bull shark, have been known to attack humans.
Sharks also show great diversity in size.