African Knife (4-5”)

Scientific Name: Xenomystus nigri 

Maximum Size and Lifespan:
Pom Pom Knifefish typically reach a maximum size of about 10-12 inches (30 cm) in captivity, though wild specimens may grow slightly larger. With proper care, they can live up to 10 years or more.

Recommended Aquarium Size:
A minimum tank size of 75 gallons (285 liters) is recommended for a single adult Pom Pom Knife. Provide a long aquarium with a tight-fitting lid, as these fish are excellent jumpers.

Water Change and Care:
Perform 30–40% water changes weekly to maintain pristine conditions, as the species is sensitive to deteriorating water quality. Maintain soft, slightly acidic to neutral water:

• Temperature: 75–82°F (24–28°C)

• pH: 6.0–7.5

They prefer subdued lighting and benefit from driftwood, plants, and caves that provide shaded areas and hiding spots. The Pom Pom Knife has poor eyesight and relies heavily on its electrosensory system, so avoid sharp decorations that could cause injury.

Tankmates:
African Knifefish are semi-aggressive and territorial, especially toward other knife species or similarly shaped fish. Suitable tankmates include:

• Peaceful to moderately aggressive medium fish such as Geophagus, Severums, or larger Gouramis

• Fast, mid- to upper-dwelling species like Silver Dollars or Congo Tetras
  Avoid fin-nippers or overly boisterous fish that might stress the knife, as well as small fish that can be mistaken for prey.

Diet:
Pom Pom Knives are carnivorous. In the wild, they feed on insect larvae, worms, and small crustaceans. In captivity, they readily accept:

• Frozen foods bloodworms and shrimp

• Sinking carnivore pellets and frozen carnivore blends can be offered once the fish is acclimated
  Feed small portions 1–2 times daily, preferably after lights are dimmed.

Overview:
The African Knife (Xenomystus nigri) is a fascinating and graceful nocturnal predator known for its distinctive undulating swimming motion generated by its long anal fin. Native to African river systems, it is the only species in its genus and lacks the electric organs seen in South American knife species. Its peaceful but cautious nature makes it a popular choice for advanced aquarists seeking a unique oddball fish.

Natural Environment:
Found across Central and West Africa, particularly in slow-moving rivers, swamps, and floodplains with dense vegetation and low light. These environments provide plenty of cover and soft, warm water.

Breeding:
Breeding in captivity is extremely rare. In the wild, they are reported to be bubble-nest builders, with males constructing floating nests among plants where eggs are laid and guarded. In aquariums, successful breeding is nearly unheard of due to their secretive nature and difficulty in sexing individuals.