The African Arowana is a long-bodied fish with large scales, long dorsal and anal fins set far back on the body, and a rounded caudal fin. Its height is 3.5 to 5 times standard length (SL). It has been reported to reach up to 1 m (3.3 ft) SL and weigh up to 10.2 kg (22 lb).
This fish is grey, brown, or bronze in colour. Colouration is uniform in adults, but juveniles often have dark longitudinal bands.
African arowanas have air-breathing organs on its branchiae, enabling them to survive in oxygen-depleted water. A suprabranchial organ allows it to concentrate small planktonic food particles and also has a sensory function