Brown ghost knifefish
Apteronotus leptorhynchus
FreshwaterFish
Care at a glance
- Temperature
- 75–84°F
- 24–29°C
- pH
- 6.5–7.5
- Adult size
- 11.8 in
- 30 cm
- Minimum tank
- 85 gal
- 320 L
- Temperament
- Mostly peaceful
- Social behavior
- Solitary
- Tankmates
- With caution
- Swim level
- Middle
- Difficulty
- Difficult
- Breeding
- No record
- Rarity
- Very rare
- Family
- Apteronotidae
- Origin
- Colombia, Venezuela
Overview
Plan on a large tank of at least 320 liters for a single fish, since it is solitary and gets territorial with its own kind and other knifefish. It cruises the middle of the tank at night and wants a steady supply of meaty foods: frozen bloodworms, brine shrimp, chopped earthworms, and similar. It is mostly peaceful with calm tankmates too big to eat but easily bullied at feeding time, so keep mealtimes generous. This is a demanding fish that needs clean, stable water.
In the wild
Brown ghost knifefish come from slow rivers and streams in Colombia and Venezuela, in dim, tannin-stained water with roots, leaf litter, and plenty of cover. They are most active at night and hide during the day, so give them a heavily shaded tank with caves, driftwood, and a soft substrate. Keep the water warm, in the mid to high 20s C, and slightly soft and acidic to neutral.
Good to know
This is a knifefish in the family Apteronotidae, not a true eel despite the long ribbon-like body. Adults can reach around 30 cm, so this is a big fish that lives a long time, often well over a decade in good conditions. Like its relatives, it produces a weak, continuous electric field used for sensing its surroundings and communicating.
Did you know
It can tell live prey apart from background clutter by reading distortions in its own electric field, which is why it hunts well in pitch darkness. Researchers study this species a lot because individual fish each hold a slightly different electric frequency, almost like a personal signature.
Common questions
What size tank does a Brown ghost knifefish need?
A Brown ghost knifefish needs at least 85 gal (320 L). It spends most of its time in the middle.
What temperature and pH does a Brown ghost knifefish need?
A Brown ghost knifefish is comfortable at 75–84°F (24–29°C) with a pH of 6.5–7.5.
How big does a Brown ghost knifefish get?
An adult Brown ghost knifefish reaches about 11.8 in (30 cm).
Related species
17.7 in (45 cm)85 gal (320 L)75–82°F (24–28°C)Black ghost knifefish
Apteronotus albifrons
17.7 in (45 cm) · 85 gal (320 L)
18.5 in (47 cm)106 gal (400 L)73–82°F (23–28°C)Elephant-nose knifefish
Sternarchorhynchus oxyrhynchus
18.5 in (47 cm) · 106 gal (400 L)
11.8 in (30 cm)100 gal (380 L)72–82°F (22–28°C)Red tail barracuda
Acestrorhynchus falcatus
11.8 in (30 cm) · 100 gal (380 L)
11.8 in (30 cm)58 gal (220 L)72–84°F (22–29°C)Spotted severum
Heros notatus
11.8 in (30 cm) · 58 gal (220 L)
11.8 in (30 cm)185 gal (700 L)75–82°F (24–28°C)Vampire tetra
Hydrolycus scomberoides
11.8 in (30 cm) · 185 gal (700 L)
7.9 in (20 cm)32 gal (120 L)72–82°F (22–28°C)Blood parrot cichlid
A. citrinellus x V. synspilum
7.9 in (20 cm) · 32 gal (120 L)