Black Ghost Knifefish

Apteronotus albifrons

It swims forwards or backwards by rippling one long fin under its belly, and finds food with a weak electric field instead of its eyes.

A semi-aggressive freshwater fish that grows to 45 cm, lives near the bottom and needs 23–28 °C, pH 6.0–7.5 and an aquarium of at least 400 L.

Care at a glance

Water

Freshwater

Temperature

23–28 °C (73–82 °F)

pH

6.0–7.5

Adult size

45 cm (18 in)

Aquarium

400 L or bigger (106 US gal)

Temperament

Semi-aggressive

Group size

Fine on its own

Swims

Bottom

Diet

Carnivore

Wild home

Amazon rivers

Good to know

• Shy. Stressed without plants, rocks or caves to hide in.
• Eats invertebrates. Hunts shrimp, snails and crabs.
• Territorial. Fights other territorial fish in its zone, especially in small tanks.
• Nocturnal. Hides and rests while the lights are on, and comes out to explore and feed at night.

Tank mates

Good company: Angelfish, Asian Arowana, Bala Shark, Boesemani Rainbowfish, Congo Tetra, Electric Blue Acara, Firemouth Cichlid, Pearl Gourami, Rosy Barb, Silver Dollar.

Will eat: Amano Shrimp, Cardinal Tetra, Celestial Pearl Danio, Cherry Barb, Chili Rasbora, Crystal Red Shrimp, Ember Tetra, Endler's Livebearer, Fancy Guppy, Ghost Shrimp, Glowlight Tetra, Harlequin Rasbora and 11 more.

Fights with: Cockatoo Dwarf Cichlid, German Blue Ram, Kribensis, Red-Tailed Black Shark, Sunshine Peacock Cichlid.

Attacks: Bristlenose Pleco, Clown Loach, Corydoras, Kuhli Loach, Otocinclus, Pictus Catfish, Siamese Algae Eater, Zebra Pleco.

Eats the newborn fry of: Angelfish, Axolotl, Betta, Black Skirt Tetra, Bloodfin Tetra, Boesemani Rainbowfish, Bristlenose Pleco, Cockatoo Dwarf Cichlid, Comet Goldfish, Congo Tetra, Corydoras, Demasoni Cichlid and 22 more.

Colours

• Classic rare

The care values are the ones Aquarius uses, based on how these animals live. Tank mates follow the game's rules: water type, temperature and pH, who can swallow whom, fin nipping, temperament and territory.