Arowanas are freshwater fish of the family Osteoglossidae. The are also known as aruanas or arawanas.
Their head is bony and their long body is covered by large scales. The dorsal and the anal fins have soft rays and are long based, while the pectoral and ventral fins are small.
Arowanas can breathe from air by sucking it into their swim bladder. The swim bladder is lined with capillaries like lung tissue.
Arowanas can grow up to 3-4 feet in length.