Fish
Whale shark
The whale shark is the biggest fish in the ocean, growing up to 12 metres (39 feet) long. It lives near the surface of the warmer oceans and far from land. The shark is brown with white spots across its back. It has hundreds of tiny teeth, but they are hardly ever used. Despite the fact its mouth is big enough to swallow two divers, the whale shark feeds only on tiny plankton, filtered from the water passing through its gills.
Gentle giant
The enormous whale shark is a gentle giant, of no threat to people. In the rare event that divers come across one of these shy creatures, it is not long before the shark slowly disappears into the depths. Whale sharks prefer to swim close to coral reefs where there are rich food supplies. Here they drift along close to the surface. Occasionally, they crash into boats, but they are often too busy feeding to notice.
Feeding
The whale shark feeds on plankton. Unlike the blue whale, which filters plankton from the water through horny plates in its mouth, these giants filter plankton through their gill slits. A whale shark needs a huge amount of food to fuel its vast bulk, so it feeds all the time, sucking in clouds of plankton, such as copepods, fish eggs, crab larvae and krill (tiny shrimp-like animals), like a gigantic vacuum cleaner.
The whale shark has about 300 tiny teeth, no more than 6 millimetres (0.25 inches) long. They are rarely, if ever, used.
Consultant: Chris Jarvis