What is the largest fish (by weight) in the world?

The largest fish in the world is the Whale Shark. It is a shark. Whales although heavier are not fish, they are mammals; otherwise they would top this list. The largest Blue Whale is over 300,000 pounds. They are on the world's heaviest animals list, actually the top three fish on this list are sharks, and there are probably more sharks that would fill the top of this list if all were included.

The largest Whale Shark weighed over 26,000 pounds. At the Atlanta, Ga aquarium you can swim with the largest fish in the world, the Whale Shark.

Whale sharks are found mostly in Southern waters, Gulf of Mexico Preferring warm waters, whale sharks populate all tropical seas. They are known to migrate every spring to the continental shelf of the central west coast of Australia.

The coral spawning of the area's Ningaloo Reef provides the whale shark with an abundant supply of plankton. The whale shark is an active feeder, targeting concentrations of plankton or fish. It is able to ram filter feed or can gulp in a stationary position. This is in contrast to the passive feeding basking shark, which does not pump water. Instead, it swims to force water across its gills.

Whale Shark. 26,000 pounds

Basking Shark 11,000 pounds

Great White 5,000 pounds

Blue Whale 300,000 pounds