Arapaima gigas is a species of arapaima, once believed to be the sole species in the genus. This species is only known from old museum specimens and its exact native range is unclear. This organism is the biggest freshwater fish to ever live in this world. Living in the Amazon River, the males act as mouth-brooders during spawning seasons. These organisms breathe oxygen directly from the air. Young Arapaima takes air around every 5 minutes. While the adults takes it around every 20 minutes.