Black Ghost Knifefish (Apteronotus albifrons) is an advanced-level freshwater fish that needs at least 100 gallons and 73-80°F. A velvety black, nocturnal knifefish that swims forwards and backwards using a long ribbon fin. It is sold small but grows over a foot long, hides all day, and is sensitive to salt, strong medications and poor water.
Care facts at a glance
| Scientific name | Apteronotus albifrons |
|---|---|
| Family | Apteronotidae |
| Origin | Amazon and Paraguay basins, South America |
| Adult size | 12-20 in |
| Minimum tank | 100 gallons |
| Temperature | 73-80°F |
| pH | 6.0-7.5 |
| Temperament | Peaceful with large fish, eats small fish |
| Social behavior | Solitary |
| Swim level | Lower to mid |
| Difficulty | Advanced |
| Diet | Carnivore: frozen bloodworms, mysis, krill, earthworms, sinking meaty pellets |
| Typical lifespan | 10-15 years |
Quick tips
- Provide hiding places like pipes and caves.
- Do not keep with fish small enough to eat.
- Avoid copper and use fish medications with extra care.
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