- It is the largest freshwater fish in the world, only rivaled by the Beluga sturgeon.
- The Arapaima is also called a pirarucu.
- The fish rises to the surface of the water and inhales air in a noisy, distinctive gulp, which is reported to be heard for long distances.
- Their tough bony scales help defend them against piranha nipping.
Amazon River Basin
Floodplain lakes, large tributaries, and flooded forest
Up to 15 feet long and 441 pounds
Plankton, insects, crustaceans, earthworms, snails, and (sometimes) other fish
Arapaimas are in the order Osteoglossiformes, or bony tongues. They get this name because most of their teeth are on the roof of their mouth or on their tongue. The body of this fish is streamlined, with long dorsal and anal fins set back close to its tail. This is commonly seen in fish that have to lunge to catch their prey. They have a gray to dark greenish-yellow body with bright red scales toward the tail. The head is large and ventrally compressed with small eyes and a very large mouth.
The animal’s life cycle is affected significantly by the flooding that occurs seasonally in the Amazon River Basin. For half of the year the Arapaima benefit from an abundance of water; however, the other half of the year they experience drought conditions. Arapaima have adapted to this by laying their eggs while the water is low, and by breathing air. Their swim bladder is modified into a primitive lung which allows them to take in air from above the surface.
Spawning is regular year by year, according to the season. As the water level rises during flood season (May to August), the eggs hatch and the offspring prosper. The giant arapaima is a mouth-brooder, holding the eggs in their mouth until they hatch. These fish have been known to guard both the eggs and the offspring.