The species is the lone entry in the monospecific family Pantodontidae
. It lives in the waters of the Cross River system of West Africa, and as its ecological niche is just below the water surface, it has evolved an escape behavior that is a jump into the air.
Teleost fishes make up the most diverse group among the vertebrates, encompassing an estimated 20,000 living species divided into approximately 38 orders (Richter et al., 2000), among them that of the Osteoglossiforms, which comprise two families, the Osteoglossidae and the Pantodontidae
. Today, Arapaima gigas is classified as Arapaimidae, which is endemic to the Amazon basin and an obligatory air-breather (Val; Almeida-Val, 1995).