The arapaima is the largest freshwater-scaled fish native to the Amazon Basin. It is also called pirarucu in Brazil and paiche in parts of Spanish-speaking South America.
Arapaima can grow beyond 2 metres long and weigh well over 100 kilograms, although exact maximum records vary. Its broad, armour-like scales help protect it from piranhas and other predators. The fish must regularly surface because it breathes atmospheric air with a modified swim bladder.
Arapaima populations have declined in some areas because of overfishing, but community management has helped them recover locally. The species is sometimes confused with giant catfish such as the piraíba, but arapaima is a scaled bony fish rather than a catfish.