Black ghost knifefish
Apteronotus albifrons
A nocturnal electric fish that glides by rippling a single long fin; it grows to nearly 20 inches and eventually eats small tank mates.
Key facts
- Body length
- 19.7 in without fins
- Minimum tank
- 202 gallons
- Group
- Alone is fine
- Temperament
- Semi-aggressive
- Care level
- 4 / 5
- Lifespan
- Not well documented
- Diet
- Frozen bloodworm, brine shrimp, mysis, sinking carnivore pellets
- Origin
- Northern South America
- Hardier than5%
- Bigger than97%
- Calmer than28%
Water: their range vs yours
Black ghost knifefish tank mates
- Clown loachGets along in shared water.Good mates
- Common plecoGets along in shared water.Good mates
- Leopard sailfin plecoGets along in shared water.Good mates
- Assassin snailGets along in shared water.Good mates
- Bladder snailGets along in shared water.Good mates
- Malaysian trumpet snailGets along in shared water.Good mates
- Mystery snailGets along in shared water.Good mates
- Ramshorn snailGets along in shared water.Good mates
- Bala sharkGets along in shared water.Good mates
- Elephantnose fishGets along in shared water.Good mates
- Kissing gouramiGets along in shared water.Good mates
- Senegal bichirGets along in shared water.Good mates
- Blue dolphin cichlidTwo territorial bottom-dwellers: need ≥ 16500 cm² of floor, tank has 5612 cm².Risky
- Chinese algae eaterTwo territorial bottom-dwellers: need ≥ 17550 cm² of floor, tank has 5612 cm².Risky
- OscarTwo territorial bottom-dwellers: need ≥ 19800 cm² of floor, tank has 5612 cm².Risky
- SeverumBlack ghost knifefish can eat young or small Severum; adults are big enough to be safe.Risky
- Dwarf orange crayfishBlack ghost knifefish eats dwarf shrimp: Orange dwarf crayfish (CPO) (PROP).Risky
- Red swamp crayfishTwo territorial bottom-dwellers: need ≥ 10800 cm² of floor, tank has 5612 cm².Risky
- Neon tetraBlack ghost knifefish can eat Neon tetra: prey body depth 0.7 cm ≤ mouth 10.0 cm.Avoid
- Harlequin rasboraBlack ghost knifefish can eat Harlequin rasbora: prey body depth 1.1 cm ≤ mouth 10.0 cm.Avoid
- Fancy guppyBlack ghost knifefish can eat Fancy guppy: prey body depth 0.8 cm ≤ mouth 10.0 cm.Avoid
- Panda corydorasBlack ghost knifefish can eat Panda corydoras: prey body depth 2.4 cm ≤ mouth 10.0 cm.Avoid
- OtocinclusBlack ghost knifefish can eat Otocinclus: prey body depth 0.7 cm ≤ mouth 10.0 cm.Avoid
- Cherry shrimpBlack ghost knifefish can eat Cherry shrimp: prey body depth 0.8 cm ≤ mouth 10.0 cm.Avoid
How we check
The numbers the tank model uses for black ghost knifefish: water as ideal and tolerated ranges, bioload from adult mass, space, flow and how they act on other species.
- Standard length
- 50 cm (TL)
- Adult mass
- 503.14 g
- Bioload at 25 °C
- 62.47 BU
- Min. water
- 648 L net
- Min. footprint
- 180 × 60 cm per specimen
- Min. height
- 60 cm
- Group
- 1+ (best 1)
- Swims in
- bottom, middle
- Flow
- moderate
- Body / fins
- slender eel, normal fins
- Diet type
- carnivore
- Fin nipper
- none
- Sensitive to
- copper, salt, nitrate
Sources: Seriously Fish: Apteronotus albifrons · FishBase: Apteronotus albifrons
Care notes
Black ghosts live over sand in flowing rivers and flooded forests of northern South America. They are most active in dim light and sense their surroundings with a weak electric field.
An adult needs a 6-foot tank of 180 gallons or more with sand, tubes and plenty of hiding places. They are quarrelsome with their own kind, sensitive to poor water and will eat small fish once grown.
Questions
What size tank does a black ghost knifefish need?
At least 202 gallons (648 litres of water after decor). Adults reach about 19.7 inches without fins.
How many black ghost knifefish should be kept together?
One is fine. They do not need company of their own kind.
What water do black ghost knifefish need?
73–82 °F, pH 6–8 and 5–10 dGH. Black ghost knifefish come from Northern South America.
How long do black ghost knifefish live?
Not well documented with good care.
What fish can live with black ghost knifefish?
Good tank mates include Clown loach, Common pleco, Leopard sailfin pleco, Assassin snail and Bladder snail. Each is checked both ways for size, fin nipping, temperament, territory and shared water.