All fish / Notopteridae

African Knifefish

Xenomystus nigri

Also known as african brown knifefish, african knife fish, false featherback, brown knifefish, african brown knife, ปลากรายแอฟริกา, ikan pisau afrika, アフリカンナイフフィッシュ, 非洲黑魔鬼, 非洲刀鱼

A plain brown, blade-shaped fish with no dorsal fin that swims by rippling a long anal fin running along its belly, letting it move forwards or backwards with ease. It is shy and nocturnal, and people keep it for its unusual shape and graceful movement, and because it is one of the smaller knifefish.

Care at a glance

Care level

Moderate

Temperament

Semi

Adult size

20 cm

Temperature

24 to 28 °C

pH

6 to 7.5

Smallest tank

200 litres

Keep as

Singly or in a group of 4 or more in a large tank

Diet

Carnivore: bloodworm, brine shrimp, earthworms, prawn, small fish and sinking carnivore pellets

Swims

Bottom of the tank

Lifespan

10 to 15 years

Water

Freshwater

Wild range

West and Central Africa: Niger, Volta, Chad, Congo and Nile basins

Breeding

It scatters eggs among plants or roots, and in the wild spawning is tied to the rainy season. Breeding in home aquariums is rarely reported, and most fish on sale are wild caught.

Good to know

It will eat small fish such as neon tetras, and adults can squabble among themselves, so give it plenty of caves and dim lighting. It can breathe air and may jump, so keep a tight lid and leave a small air gap at the surface.