African knifefish

Care at a glance

Overview

This is a night-active knifefish that hides among wood, roots, and caves during the day and comes out to feed after dark. It is best kept one to a tank, as it can be aggressive toward its own kind and toward similar bottom fish in tight quarters. It will eat small fish and shrimp it can swallow, so choose calm tankmates too large to be seen as food. Feed live and frozen foods such as earthworms, shrimp, and mussel in the evening. Give it plenty of shaded cover and a tank of at least 200 liters.

In the wild

Xenomystus nigri lives in slow, densely vegetated freshwaters across West and Central Africa, including forest streams, swamps, and pools that are often dim and low in oxygen. Give it soft, gently filtered water with plenty of shade from plants, wood, and overhangs. Keep the temperature between 23 and 28 degrees Celsius and the pH on the soft side, from about 6 to 7.5. Subdued lighting brings out its natural behavior.

Good to know

The African knifefish is a member of Notopteridae, the featherback or knifefish family, and grows to around 30 centimeters. It has the tapering, blade-like body typical of the group but is unusual in lacking a dorsal fin entirely, moving instead by rippling its long anal fin. It is an obligate air breather and rises to the surface to gulp air, sometimes producing an audible note as it does. Spawning in aquaria is rarely recorded.

Did you know

The African knifefish is an air breather that rises to gulp from the surface, and it can make a barking or bell-like sound as it swallows air, thought to help it communicate in murky water.

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