African Arowana, Heterotis niloticus

The African arowana is native to the African region of Sahelo-Sudanese, Senegal, Gambia, also in the basins of Corubal, Volta, Oueme, Niger, Benoue, and Nile rivers, Lake Chad and Lake Turkana. This species is also found in parts of eastern Africa. The young live in swampy areas where there is an abundant supply of aquatic vegetation, while the adult live in the open water of lakes and rivers. It has been introduced in other countries of Africa and Madagascar, but has been reported by some countries to have a negative impact on the ecology.

The African arowana can reach a length of 3.28 feet and weigh 22 lbs. It has a long body with large scales, and a short head. Both the dorsal fin (top fin) and the anal fin (bottom fin) are long and spineless, and set far back on the body ending close to the small rounded caudal fin (tail).

The color of this species can be brown, gray, or bronze. The young commonly have a dark band lengthways of the body. This fish has an air-breathing organ which allows it to live in water that has no oxygen.

The main diet of the African arowana is vegetation, algae, and zooplankton, but will sometimes feed on small insects. It is considered a mud feeder that has an organ to separate the small food particles from the other particles it takes in.

During the wet season, the African arowana will build a circular nest in swamps and flooded areas. The bottom of the nest is either clay or mud and the walls are made from plant debris, which will extend above the surface. After spawning the adult fish will leave the nest through a hole in the wall. The African arowana is an egg laying fish and after hatching, the young will leave the nest 5 days later and be protected by the male.

Kingdom: Animalia

Phylum: Chordata

Class: Actinopterygii

Order: Osteoglossiformes

Family: Osteoglossidae

Subfamily: Heterotidinae

Image Credit: George Albert Boulenger/Wikipedia