Brown Ghost Knifefish

Apteronotus leptorhynchus

Brown Ghost Knifefish (Apteronotus leptorhynchus) — Varies care, Peaceful, under Other. Minimum tank in the app: 85 US gal min; aim for 75–84°F and pH 6.5–7.5. The Brown Ghost Knifefish is ideal for dedicated aquarists looking to keep a unique, mid-swimming inhabitant that thrives in larger, well-maintained setups.

Brown Ghost Knifefish (Apteronotus leptorhynchus) in a planted freshwater aquarium
Care levelVaries
TemperamentPeaceful
Min tank size85 US gal min
pH range6.5–7.5
Temperature75–84°F
Max size15.7 in (40.0 cm)
Captive lifespan10–15 years
SchoolingNo

Captive lifespan reflects typical experience in a home aquarium, not maximum recorded age; genetics, sourcing, and care vary.

Natural distribution

South America

  • South America

Regional colours match the stocking calculator’s origin map.

Brown Ghost Knifefish Tank Setup

To accommodate the Brown Ghost Knifefish, prioritize a spacious tank with a minimum volume of 320 liters, ensuring good filtration for its moderate bioload. Use a mix of open swimming areas and dense vegetation or decor to create hiding spots. Aim for subdued lighting to mimic its natural habitat, and consider a sandy substrate to protect its sensitive body.

What Do Brown Ghost Knifefishs Eat?

Omnivorous by nature, this fish consumes a varied diet, but it prefers meaty offerings and may compete for food if housed with faster feeders. To promote health and vibrancy, incorporate high-quality pellets, live or frozen foods, and consider feeding at multiple locations to reduce competition.

Brown Ghost Knifefish Tank Mates

Ideal companions include similarly sized, non-aggressive species that occupy different tank levels to minimize conflict. Small, fast-moving fish may be seen as potential competition for food, while larger, territorial species could provoke stress. Limit interactions with other knifefish, as they may engage in aggressive displays if kept in close quarters.

Are Brown Ghost Knifefishs Good for Beginners?

Care demand varies with setup and individual fish; use the numbers above as your baseline. Aquarists often underestimate the space requirements and neglect the importance of tank structure, leading to stress and territorial disputes. failing to monitor water quality can exacerbate health issues, as the Brown Ghost Knifefish is sensitive to environmental fluctuations.

Building a community? Run the full list through the stocking calculator before you add anything else.

Log tests and reminders in App-aquatic—free, same data you see here.