African Arowana, African Bony-tounge 
Synonyms: Clupisudis niloticus, Sudis niloticus
Physical description: An elongated, laterally compressed species with a somewhat level back profile. The anal and dorsal fins run along the last one-third of the body. There is a cleft between these fins and the caudal fin. The scales are large and the head is covered with bony plates. The general coloration is a light olive to silver gray, often with a silver iridescence. The head is small, while the eye is large.
Size/Length: To 36" (90 cm)
Similar species: None
Habitat: Western and central Africa.
Aquarium: A tank measuring 48" (122 cm) with a capacity from 50-70 gallons (190-266 L) is only sufficient for smaller individuals, under 16" (41 cm) in length. Larger specimen require a tank measuring at least 60" (152 cm) with a capacity exceeding 90 gallons (342 L). The tank should be well-covered. Use a layer of floating plants to diffuse the lighting. Leave large open swimming areas and use large plants in the background. The tank should be arranged in dark colors.
Water chemistry: pH 6.7-7.5 (7.0), 4-12 dH (9), 75-86°F (24-30°C)
Social behavior: This species is combative towards its own species and should be kept singly. Otherwise this species is relatively unaggressive towards fish that it can not swallow. Small fish may be consumed by this predatory species.
Suggested companions: Larger Mormyrids, Haplochromis and related cichlids, Xenomystus, Synodontis, Hemichromis, Cichlasoma, Astronotus, Anostomus, Leporinus, Pacus, Silver Dollars, Pimelodids, Loricarids, Knifefish.
FOOD: A plankton and filter feeder by nature that usually accepts live worms, fish, insects, and shrimps in captivity. Acclimated specimen may accept pellets.
Sexual differences: Difficult to distinguish.
Breeding techniques: Breeding has been unsuccessful in captivity because of this fish's size. Spawning has been observed in nature. A large, circular nest is built from plants and mud in a shallow pool. It is built at the beginning of the spawning season by both parents, and its construction takes four to eight days. The sides of the nest reach up to 10" (25 cm) out of the water. The female enters and lays her amber-colored eggs along the inner walls of the nest. She exits and then the male jumps over the embankment, where he fertilizes the eggs. The female participates in brood care, guarding both the eggs and the fry. The fry are said to feed upon plankton.
Breeding potential: 10. Not possible in aquaria.
Remarks: These fish are only suitable as a juvenile for most private aquariums. This species is easily spooked, and may panic and throw itself against the tank glass. H. niloticus is a filter feeder which obtains nutrients in nature by filtering plankton and other micro-organisms through its gills.
Difficulty of care: 7. Besides reaching a large size, some report that the African Arowana is troublesome to feed. This species is generally hardy once acclimated.