All fish / Apteronotidae

Black ghost knifefish

Apteronotus albifrons

Also known as black ghost knife, black ghost, bgk, black ghost knife fish, ghost knifefish, ปลาไนฟ์ดำ, ブラックゴースト, ikan black ghost, 黑魔鬼, 黑鬼刀

This is a long, flattened, velvety black fish without a dorsal or proper tail fin. It has a white blaze on the snout and two white bands near the tail. It swims forwards and backwards with a ripple of its long anal fin and finds its way with a weak electric field, and keepers love its odd movement and shy, nocturnal habits.

Care at a glance

Care level

Moderate

Temperament

Semi

Adult size

40 cm

Temperature

23 to 28 °C

pH

6 to 7.5

Smallest tank

400 litres

Keep as

Best kept singly; adults fight with their own kind

Diet

Carnivore: bloodworm, brine shrimp, mysis, chopped prawn and sinking pellets, fed in the evening

Swims

Bottom of the tank

Lifespan

10 to 15 years

Water

Freshwater

Wild range

South America: Amazon, Orinoco and Paraná basins (Venezuela to Paraguay)

Breeding

Captive breeding is rare and happens mainly on commercial farms in Southeast Asia. There, spawning is triggered by imitating the rainy season with softer water and big water changes. Eggs are scattered among rocks, and in home aquariums it hardly ever succeeds.

Good to know

It can reach 40 to 50 cm, so it will need a large tank, and it will eat small fish and shrimp. Give it caves or pipes to hide in, use a secure lid, and avoid copper-based medicines because it is sensitive to them.