13 Black Ghost Knife Fish Facts: Everything You Should Know

Black ghost knife fish have become famous for their appealing appearance. They’ve also received a lot of attention from aquarists. We have discovered that there’s a ton of misinformation regarding the fish species.

Black Ghost knife fishing is more challenging than other species of freshwater. The reason for this is their particular requirements and their size.

We’ve never seen a ghost knife fish quite like this. It’s difficult to forget when you catch one in the flesh!

This guide will provide all you need to know about the fish. You’ll be able to identify their tank mates of choice as well as their diet, size, and any other information by the close of this article.

Black Ghost Knifefish Facts & Overview

Care Level:Intermediate
Color Form:White/Black
Lifespan:10 – 15 years
Size:20 inches max
Minimum Size of Tank:100 gallons
Tank Set-Up:Tropical Freshwater
Compatibility:Peaceful medium size fish

The most popular Knife Fish can be described as known as the Black Ghost Knife Fish. The fish was earlier identified as Gymnotus albifrons, or Apteronotus pasan. Nowadays, the fish is known as Apteronotus albifrons.

It is also called the Apteronotidae Eel, and Black Knife.

South American tribes tell an interesting tale of the fish. The tribes that live in the Amazonian jungle believe that the fish house souls of those who have passed away.

These stories form the basis for the name that is commonly used Ghost Knifefish.

They typically are nocturnal and rely on electrolocation to navigate in dark waters.


If taken care of properly A shark with a black ghost knife could last for about 10 years. In some instances, the fish can live for at least 15 years!

Their life span is dependent on their overall health as well as after they have been purchased. Genetics plays an important factor. It is possible to do your best using the resources you have and the fish is likely to remain for a long period of duration.


When fully grown, the average black ghost knife fish measures between 18 to 20 inches. It is often misunderstood. Many potential buyers believe that they are less than they really are.


It can be bought on the internet or in pet stores for as little as $7.

Behavior and Temperament

Black ghost knife fish are usually independent and like to take control of their own lives. These are lively fish, and would rather be to themselves.

They can be found in and around hidden places near the substrate in search of food. Anything else can cause additional stress.

They also have an aggressive streak.

They can only display this behavior only when they are with other ghost-like fish that are black. However, this doesn’t mean that you shouldn’t keep multiple fish within the same tank.

They will not be aggressive toward each other as long as they have plenty of space. They may become extremely grumpy when they are eaten by other species.

Black Ghost Knife Fish is an exotic freshwater fish that originates originally from South America. They are nocturnal fish that tend to be active during the night, and then sleep throughout the day.

They are active mainly at night but suffer from poor vision, which is why they can be seen hunting and communicating using an electronic field.

These fish are timid and like being alone. However, they could be aggressive when in a group of Knifefish. After they’ve settled into their new surroundings and are comfortable, they move closer to the foliage or the substrate, as well as other plants.


The Black Ghost Knife Fish is as the name implies completely black, with two white rings on its tail, and a white stripe running across its back.

It’s, not surprisingly, in the shape of a knife. There aren’t any caudal or dorsal fins.

Their bodies are long and flat with a length of up to 20 inches once fully developed. Between the stomach and the back, the anal fin is a part of the body. This creates an elegant swimming style.

This Knifefish species does not have scales. The species is very sensitive to conditions in the water as well as infections. It also lacks any protection from scales.

Black Ghost Knifefish is able to emit and also receive electrical signals. The organ in the tail generates an electric current. These cells are located on the surface of fish and serve two functions for communication and electrolocation.

It’s fascinating to study the difference in electrogenesis between both genders. Although there isn’t any clear gender difference, it has been proven that males have more frequencies than females.

Habitat and Tank Conditions

The Black Ghost Knife Fish can be seen throughout the Amazon River, its tributaries, and lakes of fresh water in Peru.

The waters are full of vegetation and provide numerous areas to hide. The lack of lighting and the moderate flow causes the water to become murky.

Water is also neutral in pH as well as warm.

They will have an incredibly soft sand surface that won’t scratch. This is important since they do not have scales.

These freshwater habitats in tropical waters house many insects, which provide plenty of insect eggs for Black ghost knives to consume.

Black Ghost Knife Fish in captivity require a living space that is as similar to their natural environment as they can. It’s easy to achieve this. We’ll guide you through the process.

Tank set up

These fish are timid and like hiding places. They enjoy the smooth, smooth rocks and the plants within their tanks.

This fish is not scale-free and therefore requires a sturdy substrate. It is possible to use small amounts of sand or fine gravel for them to stay safe. A low lighting level and a moderate or strong water flow are essential to keep the tanks.

They can withstand various conditions in the water because the water they drink is clear. The most suitable parameters for water quality for fish is the temperature range of 73.0-82.0degF and the pH range is 6.0-88.0 and a hardness range of 5-19 dGH.

Black Ghost Knife fish is a freshwater species that can endure conditions in the brackish.

Many fish enthusiasts find their fish in tubing or filters in their canisters. To avoid surprise, be sure to make use of pre-filters and make sure to cover any tubes that enter your tank when making your aquarium.

A UV sterilizer can be a good purchase since they are prone to disease and fish that are scaleless.

What size of aquarium is required?

Black Ghost Knife Fish can be an enormous fish that needs an aquarium that is at least 100 Gallons.

How many bottles can be stored per gallon?

They’re not aggressive with other tankmates like peaceful Cichlids. However, they could be hostile when sharing areas with similar or identical species.

You’ll need more than 80 gallons for each fish, if you keep them in a group.

Tank Mates

They’re great for aquariums in the community, even though they’re semi-aggressive fish.

The fish will be its best in a tranquil group of fish similar in size and temperament, like tranquil Cichlids and calm Catfish.

Black Ghost Knifefish can become aggressive if they are forced to be in tight areas or have no hiding spots.

They can also be loud when they live in a group with other members of the same species or of a similar one.

Make sure that the tank buddies you are adding have a minimum diameter of 6 inches wide and are extremely tranquil.

You can build an ideal community using tranquil Catfish, Angelfish, and vast tranquil Cichlids.

Corydoras make excellent aquarium companions and also help to keep it fresh.

Tankmates should have similar preferences for water conditions. This is not the case for species like Goldfish who prefer cooler temperatures.

It is possible for you to maintain the Black ghost knife fish growing by introducing smaller fish, such as Tetras as well as Guppies, Barbs, Rasboras, or barbs.

The Black Ghost’s most loved snack, smaller crustaceans as well as gastropods such as snails or shrimps aren’t recommended. They’re more likely to be eaten at night.

This fish shouldn’t be kept in a tank with aggressive fish or smaller fish that are thought of as food.

Black Ghost Knife Fish and the Keeper of the Heart

If you own a big enough tank that allows for them to set up their own territory and establish their territory, the idea of keeping Black Ghost Knifefish together may not be the best option.

Be careful

Black Ghost Knife Fish should be handled by experienced aquarists since they can be difficult to keep.

This fish isn’t capable of scaling and is extremely sensitive to the presence of chemicals and other diseases that are present in water. It is possible to purchase an ultraviolet sterilizer.

Remember that copper-based medicines are very harmful for fish.

Knifefish may develop skin flukes which include Ich Disease. Fish can scratch and scratch around the tank. If they’re treated properly, they’ll be able to recover quickly. If you suspect you have an infection, increase temperatures to 86 degrees Fahrenheit. The growth and reproduction of parasites are affected by the higher temperatures.

They are raised commercially in Indonesia and are ideal for wild populations that live in South America.

Be aware of the size of the animal prior to you purchase the animal. If the animal’s size is greater than the 5-inch mark, it’s likely to be wild.

Parasites and other illnesses are often carried from wild animals. To ensure that no harmful organisms are introduced into your aquarium, ensure that you quarantine them.

Recommendations for Food & Diet

Black Ghost Knife Fish is a carnivore fish species. They consume small fish and worms, as well as invertebrates’ larvae.

It won’t harm the tank and the fish must be fed frozen or fresh foods like brine shrimps, bloodworms, or blackworms.

They can also be fed tubifex worms and Krill. But they won’t be able to make pellets or shreds as quickly as you’d prefer.

They are more likely to steer clear of dry food.

To ensure that your fish have an immune system that is healthy It is crucial to provide them with a varied healthy and well-balanced diet.

It is recommended to feed them enough food every day to keep them happy for a short time. They are sleepers and should be fed in the evening or late in the evening.

They may struggle to eat initially. Black Ghosts can be shy initially and it may require some time to come out of their hiding places.

Hobbyists can also feed their pets on their own. You may want to try this out however it’s going to take some time. Although it isn’t easy to properly train your fish it’s also extremely satisfying.


Black Ghost Knife Fish should not be kept in tanks. Certain hobbyists claim to have successfully bred them; however, the methods used are frequently disputable.

Breeding success has occurred for them by several commercial fishermen in Indonesia. They’re extremely private about their achievements and this is why it remains unanswered.

They are among the most sought-after breeders:

  • Large tanks (at minimum 100 gallons).
  • Aquarium with lushly planted plants
  • There are many places to hide.
  • The tank is flooded and drained.

Caves can be found in other protected zones. They’re typically yellow with an average dimension in the range of 0.08 inches. It takes only three days for them to create their eggs.

After eggs have been laid, parents must be kept away from their young children. The eggs could be eaten by parents in the wild, and they do not seem to have any strong parental instincts.

When the fry has been released, they should be provided with a small number of meals. This could be infusoria, baby brine shrimp, or flake food items.

Many aquarists do not get to the stage where they can raise Black Ghost Knife fry. If you manage to accomplish this Please share your experiences with other aquarists to assist them, and shed information about the mystery.

What’s coming up?

Black ghost knife fish care can be extremely rewarding if you’re willing to go to the task. The fish are enjoyable to watch swimming throughout the tank.

If you are aware of how much effort is required to get this species, you are able to decide if they’re the right species for you.

If you are considering buying the fish, we urge prospective owners to be transparent. It’s not wise to buy a fish you aren’t sure how to handle.

We’re here to assist you with any questions regarding black ghost knife fish. We want to assist and inspire as many aquarists as we can.


Black ghost knife fish can be popular. They are beautiful in their swimming style and are comfortable once they’ve settled into the tank.

Knifefish, just like all species of eels, have an electro-sensory device utilized to determine and communicate the location of the animal.

They are susceptible to illness and are very picky eaters. It is essential to have some knowledge prior to keeping them.

The fish is active during the night and is not nocturnal. Carnivores eat brine shrimps, worms, and even insects.

Aquarists have managed to teach their Knife Fish to take their food using their hands over time.

Are you a Black Ghost Knife Fish owner? Do you have any experiences to share? the comment section below.


Dibyajyoti Bordoloi is the founder of CageHeaven.com, an experienced pet breeder, fish-keeper, blogger, and owner of a successful pet breeding farm. He is also a proud member of the Center for Wildlife Rehabilitation And Conservation (Assam), the Marine Aquarium Societies of North East India, and the Nature Conservancy of Assam.

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