Africa Aronawa Fish (Heterotis niloticus)
The African arowana, also known as Nile arowana (Heterotis niloticus), is a species of bonytongue. Despite being called an “arowana”, the African arowana is more closely related to arapaimas, the only other members in the Arapaimidae family, than the South American, Asian and Australian arowanas in the Osteoglossidae family (Arapaimidae is sometimes included in Osteoglossidae). Compared to these, the African arowana has a more terminal mouth and is the only one that feeds extensively on plankton not considered carnivorous.
Name ORIGIN: The name ‘Aronawa‘ is taken from Old Tupi or classical Tupi which was spoken by the native Tupi people of Brazil, mostly those who inhabited coastal regions in South and Southeast Brazil. It belongs to the Tupi–Guarani language family, and has a written history spanning the 16th, 17th, and early 18th centuries.
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 gray, brown, or bronze in color. Coloration is uniform in adults, but juveniles often have dark longitudinal bands.
African Aronawa is widespread throughout Africa, where it is native to all the watersheds in Sahelo-Sudanese region, Senegal, and Gambia as well as parts of eastern Africa. This range includes the basins of the Corubal, Volta, Ouémé, Niger, Bénoué, and Nile Rivers as well as those of Lake Chad and Lake Turkana. It has been successfully introduced to Côte d’Ivoire Sanaga and Nyong rivers in Cameroon, and Ogooué River in Gabon, as well as the lower and middle Congo River basin, including Ubangui and Kasaï Rivers. It has also been introduced in Madagascar.
In Nigeria It has been confirmed available in Ondo , Cross River, Delta, Rivers, Lagos, Edo and Ogun. It is mostly available in the wild and captured by fishermen with different kinds of tackles. They are not carnivorous so “NO CATCHING WITH FISHING HOOK” but majority of fishermen use nesting snares, meshed-wires cage, dragging nets, fishing spears and other techniques to catch them from the wild.
Reactions in The Wild
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. It has power and strength when it comes to locomotive actions. The adult have the ability to break nylon monofilament fishing net of 0.50mm — 1mm if trapped to set itself free. It has power but no durable strength.
While South America has two Osteoglossum arowanas (the Silver arowana and the Black arowana), and Asia and Australasia have three Scleropages, Africa has a single species — Heterotis niloticus.
Unlike all the others, which are surface-feeding predators, the African arowana is not. It was once considered to be a filter-feeding fish, but recent studies have actually shown that it’s an insectivore, omnivore and detritivore — feeding on small particles of anything that tickles its fancy.
The feeding mode it uses varies according to its age and what habitat it is living in. Little ones, measuring 10-20cm/4-8” long, shift from feeding on small aquatic invertebrates, such as Daphnia, to seeds and detritus.
When they’re found in fresh waters, they start feeding on detritus when they hit 30-40cm/12-16” long, but when they’re found in rivers they don’t become detritivorous until they’re nearly 0.6m/2’ in length.
For not being carnivorous, fish keepers find it difficult to raise without common fish feeds in the market.
They’re rarely kept in the aquarium and have a reputation for being difficult to feed. I’ve tried to rear 3cm/1.1” juveniles before and been wholly unsuccessful.
A European Fishery practitioner said “They also tend to arrive from Africa in a somewhat emaciated state and often riddled with parasites. They’re challenging fish and for that reason are best avoided“.
Another person said “I know this is a very demanding fish to raise and I think the challenge is worth it considering the end result.”
Osteoglossids are carnivorous, often being specialized surface feeders. They are excellent jumpers; Osteoglossum species have been seen leaping more than 6 ft (almost 2 m) from the water surface to pick off insects and birds from overhanging branches in South America, hence the nickname “water monkeys”. Arowana species typically grow to around 2 to 3 ft in captivity.
African arowana is used locally as a food and has been collected in the past for the aquarium trade in Europe and the Americas, but behavior of it in captivity. It’s not feral or aggressive like its relatives.
Several species of osteoglossids exhibit parental care. They build nests and protect their young after they hatch. All species are mouth brooders, the parents holding sometimes hundreds of eggs in their mouths. The young may make several tentative trips outside the parent’s mouth to investigate the surroundings before leaving permanently.
In the aquarium
Depending on the classification system used, there are 10 types of arowana commonly kept as pets; 4 from Asia, 3 from South America, 2 from Australia and 1 from Africa.
Arowanas are solitary fish and only allow company while young; adults may show dominance and aggression. Some compatible species often partnered with this fish are clown knifefish, pacu, oscars, jaguar cichlids, green terrors, gar, tinfoil barb, Siamese tigerfish, and any other somewhat aggressive fish that cannot fit in the arowana’s mouth.
These fish are best kept with live or frozen feed and they easily outgrow the tank within 8 to 10 months. An aquarium of at least 150 gallons is a minimum, while tanks upwards of 400-600 gallons is preferable. Australian species are best kept alone in aquaria