(Arapaima leptosoma)
Arapaima leptosoma is a species of freshwater fish endemic to near the confluence of the Solimões and Purus Rivers in Amazonas, Brazil. Like other members of the genus Arapaima, this fish can breathe air. It has a deep caudal peduncle relative to other species in its genus. It is the first new member of Arapaima to be described since 1847. Member species of the genus Arapaima are the largest freshwater fish in South America.