Fun Black Ghost Knifefish Facts For Kids

Abhishek Mishra
May 09, 2023 By Abhishek Mishra
Originally Published on Aug 05, 2021
Edited by Monisha Kochhar
Fact-checked by Yashvee Patel
Interesting black ghost knifefish facts for kids.
Age: 3-18
Read time: 8.5 Min

The Black Ghost knifefish, prominently found in several countries of South America, belongs to the family of ray-finned fishes Apteronotidae. The ghost knifefishes primarily originated in the freshwater and deep waters of  Brazil, Argentina, Venezuela, and Bolivia. But people usually keep them in aquariums. Around 89 species are from the ghost knife fish family and one of them is the black ghost knife fish (Apteronotus albifrons). These fishes are prominently found in the rivers of Brazil, Argentina, Venezuela, and Bolivia.

The length of a few species is around 6-10 in (15-25 cm) while species such as the black ghost knifefish (Apteronotus albifrons) are more than 19 in (50 cm) long. Unlike most fishes, the black ghost knifefishes don't have a caudal fin or tail fin and move with the help of an anal fin on the back. Another feature that differentiates the black ghost knifefishes from other species is the 'electric organ discharge' or EOD through which the fishes communicate with each other. People also refer to the fish as the cousin of the electric eel. The scaleless fish is quite aggressive as well and prey on insect larvae and fishes. The International Union for Conservation of Nature has not evaluated the conservation status of the black ghost knifefish yet.

Keep on reading to learn more interesting facts about the Black Ghost Knifefish. If you want to know more exciting information about different animals, check out giant grouper and hogfish facts.

Black Ghost Knifefish Interesting Facts

What type of animal is a Black Ghost Knifefish?

A Ghost knifefish is a carnivore fish generally found in different parts of South America prominently in the Bolivarian Republic of Venezuela and Brazil. There are around 89 species and the black ghost knifefish (Apteronotus albifrons) is the major species of the ghost knifefish.

What class of animal does a Black Ghost Knifefish belong to?

The black ghost host knife fish belongs to the family Apteronotidae. They are of the Actinopterygii class and Apteronotus genus. The freshwater fish primarily prey on insect larvae, small fishes while those living in aquariums are fed frozen meat, brine shrimp, and fish food.

How many Black Ghost Knifefish are there in the world?

The exact population of the black ghost knifefish (Apteronotus albifrons) is not known as of now but the fishes are widely distributed throughout the South American continent.

Where does a Black Ghost Knifefish live?

The black ghost knifefish (Apteronotus albifrons) and other species of ghost knife fish are primarily found in the different regions of the South American continent. The fish can easily be spotted in the rivers of Venezuela, Bolivia, Argentina, Brazil, Paraguay, and many more. From Venezuela, the Parana River in Brazil, to Amazon Basin, the black ghost fish can easily be found.

What is a Black Ghost Knifefish's habitat?

The black ghost knife fish is a tropical freshwater fish and is majorly found in rivers and great lakes of South America. Many people also love to keep the black ghost knifefish (Apteronotus albifrons) as a pet and keep them in a large aquarium.

Who does Black Ghost Knifefish live with?

Species such as the black ghost knifefish (Apteronotus albifrons) are nocturnal and remain active during the night. But during the breeding period, the fishes come together. The fish can also become quite aggressive when put in a tank with other knifefish species.

How long does a Black Ghost Knifefish live?

The black ghost knifefish (Apteronotus albifrons) lives for around 10-15 years.

How do they reproduce?

The black ghost knife fish (Apteronotus albifrons) breed only after attaining maturity. The exact process of breeding in freshwater or rivers is not known. But the black ghost knifefish are bred in fish tanks, large aquariums, and ponds. Several water parameters such as the optimum breeding temperature and consistency are required for breeding. Also, the fish tank size should be large enough, placed in a dark location for the black ghosts, and should have enough hiding places. The water temperature needs to be exactly 80.6 F (27 C). All these water parameters are required to make the female black ghosts safe. Without these vital parameters, the female would not lay eggs. Unlike, other species the black ghost knife fish found in rivers usually prey on their eggs after spawning and have no parental involvement with the eggs. People generally remove the adult ghost knife fishes after the process of spawning or mating.

What is their conservation status?

The International Union for Conservation of Nature has listed the fish species in the Least Concern category. The fish can easily be found in the rivers of South America.

Black Ghost Knifefish Fun Facts

What does Black Ghost Knifefish look like?

The black ghost knife fish is quite large and as the name suggests the fish has a black thick body with rings on the tail and a white stripe on the nose. As the fishes lack the caudal fin, they move with the help of their anal fin which looks so fascinating. Their curved body resembles huge knife. Also, they have white rings on their tail.

A black ghost knifefish taking a dive.

How cute are they?

The black ghost knifefish are quite fascinating or alluring and you can find these fishes majorly in aquariums. Their bodies are curved in shape and resemble huge knives. These fishes are best known for their electric organ and it is also said that they belong to the family of the electric eel.

How do they communicate?

Like any other species, ghost knifefishes communicate the same way. Generally, fishes communicate through their touch and some studies also reveal that by the darkening of the skin, and sense of smell these fishes communicate. A unique characteristic of the black ghost knifefish is the use of electric organ discharges or EODs. Unlike other fishes, the black ghost knifefish receive and sense the electric impulse through which they can communicate with each other when they sense the EODs.

How big is a Black Ghost Knifefish?

The black ghost knife fish is one of the biggest species of ghost knife fish. The fishes are known for their speed of growth. The average size of the black ghost knife fish is 19 in (50 cm) but some of them grow 23 in (60 cm) long. Research also suggests that the black ghost knife fish grows around 5-6 in (12-15 cm). The black ghost knifefish is five times larger than a few species of catfish.

How fast can a Black Ghost Knifefish swim?

The exact speed of the ghost knifefish is not known at the moment but the black ghost knife fish is quite active during the night. Also, the native people believe that these fishes have some ghost-like characteristics as they move very swiftly and disappear within seconds.

How much does a Black Ghost Knifefish weigh?

No information regarding the black ghost knife fish is available as of now. These fishes are quite large so may not be the quickest swimmers.

What are the male and female names of the species?

There are no such names given to the male and female species of the black ghost knife fish. People usually observe the eyes of the fish to determine the sex of the fish. The male fish have eyes on top of their head while the females have eyes on the front of their heads. Also, the female black fishes generate electric organ discharges at a higher frequency compared to the males.

What would you call a baby Black Ghost Knifefish?

People often call a baby black ghost knife fish an alevin. The term, Alevin is used to refer to newly hatched babies or juveniles.

What do they eat?

The black ghost knife fishes are found either in freshwater or in aquariums. The fishes are carnivores, the species found in rivers and lakes generally prey on small insects, fishes, and crustaceans. While those living at homes and large aquariums are fed frozen meat, earthworms, small pellets, fish foods, and plankton.

Are they aggressive?

The black ghost knife fish is quite large compared to other species of the ghost knife family and has no teeth but a beak that can harm humans, especially kids. These fishes become aggressive with other species of knifefish. Most of the other species of ghost fishes are very shy and less aggressive.

Would they make a good pet?

The ghost knife fish is often regarded as a peaceful fish of rivers and lakes but species such as the black knifefish is semi-aggressive or aggressive with their tank mates. Many people throughout the world consider the fishes as pets. But several prerequisites should be kept in mind before keeping a black ghost knife fish as a pet such as the size of the tank, suitable water temperature, the pH level, tank mates, proper diet, and many more. These fishes are one of the most beautiful and fascinating species but at the same time the hardest to care for.

If you have decided to keep them then you can find a marble black ghost knifefish on several websites or pet stores around you.

Did you know...

The Bakken Museum, situated in the state of the United States, Minneapolis has a device that converts the electric signals of the black ghost knife fish into audible sounds. Also, the female black knife fish generates electric organ discharges at a higher frequency compared to the males.

Unlike other species, the black ghost knife fish is prone to several skin diseases. White spots and parasite diseases are a few common problems.

How did the Black Ghost Knifefish get its name?

These fishes have made a prominent place in the ghost stories of the South American continent. The native tribes believe that the ghosts of the deceased inhabit the body of the black ghost knife fish. Also, these fishes move quickly to catch the prey and disappear within seconds.

Keeping Black Ghost Knifefish

Before taking them home, several things should be kept in mind such as minimum tank size, proper water conditions, the diet, and many more. It is suggested that the minimum tank size should be 100 gallons. Also, sand and fine gravel should be used to make a suitable environment for the fish. The aquarium's water temperature should be around 80.6 F (27 C), and the pH level should be between 6.5-8. The main purpose of maintaining such water conditions and arrangements is to resemble their natural habitat's wet season.

Also, the black ghost knifefish needs more space compared to other fishes. The size of the aquarium should not be less than 100 gallons as a small and confined space make the fish more aggressive. Also, it is suggested not to keep the fishes of similar species together as they could turn aggressive quite easily. People generally keep peaceful fishes such as corydoras, catfish, and discus fish with the black ghost knifefish.

Here at Kidadl, we have carefully created lots of interesting family-friendly animal facts for everyone to discover! Learn more about some other fish including brook trout, or angelfish.

You can even occupy yourself at home by drawing one on our Black ghost knifefish coloring pages.

Black Ghost Knifefish Facts

What Did They Prey On?

Crustaceans, fishes, shrimps, worms, frozen foods

What Type of Animal were they?


Average Litter Size?


How Much Did They Weigh?


What habitat Do they Live In?

rivers, freshwater aquarium

Where Do They Live?

south america

How Long Were They?

19-23 in (50-60 cm)

How Tall Were They?








Scientific Name

Apteronotus albifrons

What Do They Look Like?


Skin Type


What Are Their Main Threats?

humans, predators

What is their Conservation Status?

Not Evaluated
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Written by Abhishek Mishra

Bachelor of Arts specializing in History

Abhishek Mishra picture

Abhishek MishraBachelor of Arts specializing in History

As a content writer, Abhishek's passion for writing extends beyond professional content creation. With a Bachelor's degree in History from Ram Lal Anand College in Delhi, Abhishek is a skilled writer in both English and Hindi, bringing a creative flair to his work. He enjoys crafting satires and poetry and is dedicated to producing engaging and informative content.

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