What is the largest freshwater fish in the Amazon River?

What is the largest freshwater fish in the Amazon River? The arapaima is the largest freshwater fish commonly associated with the Amazon River.

Also called pirarucu in Brazil and paiche in parts of Peru and Bolivia, arapaima are giant bonytongue fish native to the Amazon basin. They can exceed 2 metres in length, and verified specimens have reached about 3.07 metres and more than 100 kilograms.

Arapaima are unusual air-breathers. They must rise to the surface roughly every 5–15 minutes, using a modified, highly vascularized swim bladder to supplement their gills. This adaptation helps them survive in warm, oxygen-poor floodplain lakes and makes their loud surface gulps easy for fishermen to detect.

Their large scales are flexible but armour-like, offering protection from attacks by piranhas. Arapaima are also culturally and economically important food fish, but overfishing has severely reduced many wild populations. The answer is sometimes confused with the bull shark, which can enter freshwater but is a shark rather than the Amazon’s characteristic giant freshwater fish.