Brown ghost knifefish

Care at a glance

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.

Related species

• 

  Black ghost knifefish

  Apteronotus albifrons

  17.7 in (45 cm)85 gal (320 L)75–82°F (24–28°C)

• 

  African knifefish

  Xenomystus nigri

  11.8 in (30 cm)53 gal (200 L)73–82°F (23–28°C)

• 

  Red tail barracuda

  Acestrorhynchus falcatus

  11.8 in (30 cm)100 gal (380 L)72–82°F (22–28°C)

• 

  Silver tiger perch

  Datnioides polota

  11.8 in (30 cm)79 gal (300 L)75–82°F (24–28°C)
• Flagtail prochilodus

  Semaprochilodus taeniurus

  11.8 in (30 cm)159 gal (600 L)73–82°F (23–28°C)

• 

  Banded leporinus

  Leporinus fasciatus

  10.6 in (27 cm)40 gal (150 L)68–82°F (20–28°C)