What is the largest fish?

The largest fish is the whale shark. Despite its name, the whale shark is a fish rather than a whale: it breathes through gills, has a cartilaginous skeleton, and belongs to the shark group. Its scientific name is Rhincodon typus.

Whale sharks are filter feeders. They swim with their huge mouths open, straining plankton, fish eggs, krill, and small fish from seawater. Although they can reach roughly 18 metres (59 feet) or more in exceptional records, they are generally gentle and pose little danger to people.

A common mix-up is the blue whale, which is much larger but is a mammal, not a fish. The whale shark is the largest living fish and the largest living non-cetacean animal. Basking sharks are also enormous filter-feeding fish, but they are smaller than whale sharks.