African Brown Knifefish (Xenomystus nigri) is an intermediate-level freshwater fish that needs at least 55 gallons and 72-82°F. A slim, night-active knifefish that glides backward and forward using its long fin and breathes air at the surface. It is far smaller than the clown knife, but it hides by day, hunts by smell at night, and will eat tiny fish such as neons.
Care facts at a glance
| Scientific name | Xenomystus nigri |
|---|---|
| Family | Notopteridae |
| Origin | Tropical Africa, from West Africa to the Nile and Congo basins |
| Adult size | 8-9 in |
| Minimum tank | 55 gallons |
| Temperature | 72-82°F |
| pH | 6.0-7.5 |
| Temperament | Peaceful with similar-sized fish, eats small tankmates; shy |
| Social behavior | Solitary or small group in a large tank |
| Swim level | Mid to lower, hides by day |
| Difficulty | Intermediate |
| Diet | Carnivore: frozen bloodworms, krill, chopped shrimp, sinking pellets |
| Typical lifespan | 8-10 years |
Quick tips
- Provide caves, wood or pipes to hide in.
- Leave an air gap under the lid; it gulps air.
- Do not keep with fish small enough to swallow.
San Diego water
Captive-bred stock usually adapts to San Diego tap water with slow acclimation. For best color and health, many keepers blend tap with RO/DI water. Learn the numbers in our San Diego tap water guide.
Before you buy
Make sure your tank is cycled (how to cycle a tank), check your numbers with the water testing guide, and use the compatibility guide to check tankmates. These are general ranges; individual fish and local water vary.
Find it at Pet Zone
Pet Zone Tropical Fish is a San Diego aquarium store with two locations. Stock changes daily, so call ahead if you are after a specific species or plant. Shop online at petzonesd.com.
4160 Convoy St, San Diego, CA 92111
(858) 987-0309
Open daily, 10am-6pm
Aquascaping, planted tanks
4266 University Ave, San Diego, CA 92105
(619) 283-1812
Closed Monday; Tue-Fri 10:30am-6pm, Sat 11am-6pm, Sun 11am-4pm
Monster fish, koi