Whale shark

The whale shark is the biggest fish in the whole ocean. A grown-up whale shark is usually longer than a school bus, and the very largest one ever measured was even bigger than that. Even so, it is a calm and gentle animal that swims slowly through warm, blue seas.

Its name has “whale” in it because it is so huge, but it is a true shark, not a whale. Its back is dark grey and covered in pale spots and stripes. Every whale shark has its very own pattern, so scientists can tell one from another by its spots, almost like fingerprints.

Even though it is enormous, the whale shark eats some of the smallest food in the sea. It swims with its wide mouth open and takes in great gulps of water. Special combs inside its mouth catch tiny plankton and little fish, while the water flows back out through its gills.

Whale sharks travel huge distances across the warm oceans to find these clouds of tiny food. They are friendly to people and have no interest in biting swimmers. Divers can glide right beside one as it feeds. Whale sharks live a very long time, perhaps even longer than a hundred years.

Sadly, there are fewer whale sharks than there once were, so scientists list them as endangered. Some are caught in fishing nets or hurt by big ships. People around the world are now working to keep these gentle giants safe so they can go on swimming through the sea.