What's the World's Largest Fish? The world's largest fish, a
whale shark, can grow up to 40 feet long. CREDIT: Kim Hull/Mote
Marine Laboratory The world’s largest fish is the whale shark,
which can grow to 40 feet long and weigh an average of 20 tons.
The sharks are carnivorous, but they aren’t likely to take a
nibble out of an unwary surfer – they filter plankton through
their enormous mouths while swimming at the surface. In fact,
whale sharks are so friendly that people often swim with them.
The world’s second largest fish, the basking shark, is also a
filter feeder. The largest confirmed individual shark was 41.5
feet long and weighed 47,000 pounds – though sailors say they
have seen sharks that are even larger. Whale sharks are the
largest non-whale animals in the world, and their enormous size
puts them in a class with dinosaurs. Whale sharks are a
vulnerable species, and despite conservation efforts the school-
bus-sized creatures continue to be hunted in some Asian
countries. Scientists are still tryin