Whale sharks live in the open ocean where they feed on plankton, schooling fishes, jellyfish, small crustaceans and squid. Whale sharks up to approximately 3 feet in length are eaten by blue marlin, blue sharks, great white sharks and killer whales.
Fully grown whale sharks average 32 feet in length and are well-defended by tough, thick skin with a layer of cartilage underneath. Adults often have scars and bite marks from earlier predator attacks.
Whale sharks use different strategies for feeding according to prey density. When prey density is low, they feed by swimming forward with their mouths open, filtering the water through dermal denticles lining the gill plates and pharynx. They use the same method when prey density is high but swim faster, often in a circular pattern. At medium-prey densities, whale sharks feed actively by sucking in prey.