Shoal & Stem
Back to Flora & Fauna

No photo yet

Sign in to add the first photo.

FishmediumFreshwater

African Knife Fish

Xenomystus nigri

Also known as African Knifefish, Knife Fish, African Brown Knifefish

Animalia›Chordata›Osteoglossiformes›Notopteridae

The African Knife Fish is a sleek, nocturnal predator with an elongated body and a distinctive knife-like anal fin that runs the length of its belly. Native to West African rivers, this species is relatively peaceful toward larger fish but will consume smaller tankmates. It's an excellent choice for experienced aquarists seeking a unique, active bottom-dweller with interesting behavior.

Where it's from

Native to the Congo, Imo, Kittam, Kwa Ibo and 13 other river basins

Congo - Kinshasa, Nigeria, Sierra Leone, Niger, Sudan, Gabon, Benin, Tanzania and 3 more

At a glance

Size
6 in
15 cm
Min tank
55 gal
208 L
Temp
75–82°F
24–28°C
pH
6.0-7.5
GH
71–143 ppm
4–8 dGH
Temperament
Semi-aggressive
Swims
Bottom
Lifespan
5-8 yrs

Ammonia 0 ppm and nitrate under 20 ppm.

Care

Diet

African Knife Fish are carnivorous and prefer live or frozen foods such as bloodworms, brine shrimp, and small fish. Feed 2-3 times weekly with portions they can consume in a few minutes. They are nocturnal hunters and may be reluctant to eat during the day; offer food in the evening when they become more active.

Behavior

This species is primarily nocturnal and spends most of the day hiding in caves, plants, or dark areas. At night, it becomes an active hunter, using its electrolocation abilities to navigate and find prey in low-light conditions. African Knife Fish are generally solitary and territorial, though they can coexist with larger, peaceful fish that won't fit in their mouths.

Breeding

Breeding in captivity is extremely difficult and rarely achieved in home aquariums. They require specific environmental triggers and large, heavily planted tanks with minimal disturbance. Most specimens in the hobby are wild-caught, making captive breeding impractical for most aquarists.

Member photos

Photos are added when members log a tank with this species and upload a photo in their tank journal. Add your own tank to contribute.

No photos yet — add a tank with African Knife Fish to be the first!

Sign in to vote.

Common diseases 4Ich (Ichthyophthirius multifiliis), Fin Rot, Bacterial Infection, Parasitic Infection

Ich (Ichthyophthirius multifiliis)

Symptoms

White spots on body and fins, rapid breathing, lethargy, rubbing against objects

Treatment

Increase water temperature to 28-30 C (82-86 F), perform water changes, use ich medication; quarantine affected fish if possible

Fin Rot

Symptoms

Frayed or deteriorating fins, discoloration at fin edges, progressive fin loss

Treatment

Improve water quality with frequent water changes, remove sharp decorations, use antibacterial medication if severe

Bacterial Infection

Symptoms

Open sores, ulcers on body, cloudy eyes, loss of appetite, lethargy

Treatment

Perform large water changes, maintain pristine water conditions, use broad-spectrum antibacterial medication

Parasitic Infection

Symptoms

Excessive scratching, visible parasites, weight loss, clamped fins, lethargy

Treatment

Quarantine affected fish, use antiparasitic medication, maintain optimal water parameters to boost immune system

Legality

No state or federal restrictions on record.

Not legal advice, and possibly incomplete or out of date. Rules vary by state and change over time; check with your state wildlife or agriculture agency before buying, keeping or shipping it.

The care information here is written with AI help, so it can contain mistakes. Spot one? Tell us and we'll fix it. Native range: Tedesco et al. 2017 (CC0).

Keepers’ experiences

Keep African Knife Fish? Share how it's going.

Nobody has shared one yet. A few lines on how they've done in your tank help the next keeper.

Sign in to share