The Pirarucu, also known as Arapaima gigas, is one of the largest freshwater fish in the world, native to the Amazon River basin in South America. It can grow up to 15 feet long and weigh over 440 pounds. The fish has a distinctive appearance, with a long, streamlined body and a large, bony head. Pirarucu is known for its unique respiratory system, which allows it to breathe air. It has a swim bladder that functions like a lung, enabling it to survive in oxygen-poor waters. This fish is an important species for local ecosystems and is also a popular target for fishing.