Animal-World > Freshwater Fish > Aquarium Knifefish | Knifefishes > Black Ghost Knife Fish

Black Ghost Knifefish

Black Ghost Knife Fish Family: Apteronotidae

• Puzzles
• Postcards

Black Ghost Knifefish Apteronotus albifrons Photo © Animal-World: Courtesy Ken Childs

  The popular Black Ghost Knifefish is readily distinguished from other knife fish by the white and black banded area just in front of tail fin!

   The Black Ghost Knifefish received its unusual name because of a rumor that some tribes in the Amazon jungle believe that the souls of the dead inhabit this fish. No one can substantiate this information and it may just be a story created by the people collecting the fish, but it’s a good story.

   For good reason, the Black Ghost Knifefish is the most well known species of knifefish in the aquarium industry. One reason for this is that they have been imported for decades. Other reasons include being unusual, interesting and amazingly beautiful. Until a few years ago, all offered for sale were wild caught and had been imported from South America, mainly from Brazil. The good news is that they are now being bred in Indonesia by the thousands, so much of the pressure has been taken off the wild populations. Odds are that if you see an individual of 5 inches or more offered of sale, it was collected in the wild. Specimens smaller than 5 inches were most likely produced in and imported from Indonesia.

For more Information on keeping freshwater fish see:
Guide to a Happy, Healthy Freshwater Aquarium

Distribution:
   The Black Ghost Knifefish was described by Linnaeus in 1766. Black Ghosts are found in South America throughout much of the Amazon River and its tributaries. It is nocturnal and preys on insect larvae.

Status:
   The species is not listed on the IUCN Red List.

Description:
   The black body of the Black Ghost Knifefish is flat and elongated. It has a continuous fin along the underside formed by a joining of the caudal and anal fin and moves with an undulating motion. Although they appear clumsy, they have a built in ‘radar’ system that uses low voltage electricity to help them navigate. This and their undulating lower fin allow them to gracefully move forwards and backwards through the aquarium.

Size - Weight:
  The maximum size for this fish is around 20 inches (50 cm).

Care and feeding:
   The Black Ghost Knifefish are carnivores. In the wild they are nocturnal, when the sun sets and throughout the night they feed on insect larvae. In the aquarium this is a fish hat prefers fresh or fresh frozen foods such as bloodworms, brine shrimp or blackworms.
   A full sized Black Ghost Knifefish is a big animal which requires a big home. You will need to eventually provide a tank containing 100 gallons or more if you plan on keeping one of these beauties into adulthood. Providing many hiding places with plants, smooth rocks or aquarium safe wood in a necessity. They are nocturnal and will spend most of the daylight hours hiding in a safe and secure location. Once acclimated to their new home, they should come out of hiding at feeding time. Some have even been taught to feed from their keeper’s hand.

Water Region: Top, Middle, Bottom:
  This species of knifefish spends most of its time near the bottom.

Acceptable Water Conditions:
   Temp: 73 - 82° F (23 - 28° C)
   Hardness: 5 - 19 dGH
   pH 6.0 to 8.0

Social Behaviors:
   Black Ghosts can become aggressive with members of their own species and members of other, similar species. Other than that, they are usually quite timid. They do have a large mouth so small fish or invertebrates kept in the same tank may eventually become a meal for a hungry Black Ghost.

Sexual Differences:
   Sexual differences are unknown.

Breeding/Reproduction:
   This species is being bred commercially in Indonesia but the method used is unknown. There are hobbyists that claim to have successfully bred the Black Ghost Knifefish in an aquarium but they seem reluctant to share the details. There is some information on this subject, scattered reports, but there is nothing yet documented from reputable sources so it will not be reproduced here. One thing for certain is that if you want to give it a try, you’ll need a big aquarium, probably containing 100 gallons or more.

Buy Black Ghost Knifefish From LiveAquaria.com

Availability:
  Now that they are being bred in captivity, the Black Ghost Knifefish are available all year long.
Large specimens may command a high price, mainly due to the higher costs of shipping them. Smaller specimens are quite affordable.

Author: Ken Childs

Add your comment here!
Click to see All the comments!
Latest Comments
Woah your 44g tank is way overcrowded! The knife alone will get 20". You need to rehome some fish. Koop 2009-10-10
I have a 5" black ghost knife fish in my 44 Gallon Tank along with 4 tiger barbs (1 albino), 2 flying foxes, 2 6" Firemouth Cichlids and a 10" long pleco. These knife fish are very shy. Mine will only eat if the lights are off. Mine is also a very picky eater; he only eats frozen bloodworms. I would only recommend this fish to experienced aquariasts. They are very cool. kyle 2009-07-13
Shannon your tank is way too small for your knife fish. I would recommend a tank no smaller than 4ftx18in with lots of wood or rock caves for them to hide, and feed him frozen blodworms, brine shrimp and sinking pellets. My knifefish also loves my angelfish eggs! Barry 2009-06-11
Hi, I had purchased this fish [pair] a day ago which were 4"in length. They died the next day due lack of O2 supply, 4 6hrs. I then bought another pair which are smaller than the earlier. The new ones swim head to head very often. I want 2 know if they are aggreing with each other or fighting, and my tank size is (LxBxH) 18x9x12... is this enough. Shannon 2009-04-23
My black knife fish just died and I am going to get another asap. He grew to be 20"..and I had him for 6 years. He never bothered anything larger than a guppy. He ate only when the lights were out..so my husband got a blue light set up so we could watch him eat. He became very tame. I miss him. He was 4" long when I got him and I paid $25.00 at the time. He was worth every penny. I housed him in a 55 gallon and he did just fine these last 6 years. If you want an interesting fish..this is the one. R. Carter 2008-10-17
Some of the coolest comments:
I got two black ghost knifes a year ago and they get along fine. I've been feeding them frozen bloodworms and they've started eating out of my hand. They seem to have gotten used to the light, now it looks like they couldn't care less if the lights are on or off, but when I turn off the lights, they immediately rush out of their caves and swim vertically along the top of the water, looking for food. Most awesome fish ever! Josh 2009-09-02

Back to Aquarium Knifefish | Knifefishes