The Whale Shark, Rhincodon typus, is a large fish. The smallest ever recorded was about 15 inches (38cm) long, but there are reports of Whale Sharks over 20 m (62 feet) long although there is some lack of evidence concerning ones this big. There have certainly been accurate records of Whale Sharks 12m (37 feet) long.
The Whale Shark species is possibly as much as 60 million years old, but has only been known to western science since about 1828. Individual Whale Sharks may live for as much as 100 years, but as with many things about the interesting species there is some guess work concerning their life span. The Whale Shark is listed as migratory and vulnerable, but again this is partly based on how little we really know about the Whale Shark.