The largest fish is the whale shark (Rhincodon typus). It holds the title for being the largest known extant fish species. Whale sharks can reach incredible sizes, with average lengths of about 32 to 40 feet (9.8 to 12.2 meters). However, some individuals have been documented measuring over 60 feet (18.3 meters) in length. They can weigh up to an estimated 20 tons (18 metric tons) or more. Despite their massive size, whale sharks are filter feeders, consuming plankton, small fish, and other microscopic organisms by filtering them through their gill rakers.
It’s important to note that although the whale shark is the largest fish, it is not a whale. It is a cartilaginous fish belonging to the same group as sharks and rays.