Black Ghost Knifefish: Freshwater Tropical Specie

Last updated on December 24th, 2022 at 11:04 am

The Black Ghost Knifefish looks extremely incredible and is the rarest and exciting fish species that you can have. By their appearance, they look super attractive, which is one of the major causes of their attention.

Among all the fish species, the black ghost has the highest demand from aquarists all around the globe. It’s not possible if you don’t get fascinated once you interact with them. This species is convenient freshwater tropical to have, whereas many freshwater fishes are very easy to keep. However, they require lots of care, attention, specific food items, and much more! All of this is due to their unique size and other body conditions.

In the following guide on black ghost Knife fish, we will talk about every essential that you must be aware of before having this species in the aquarium. We have covered all details regarding its requirements, appearance, diet, behavior, including tank mates.

Overview of Black Ghost Knife-fish

  • Scientific name: G. albifronsFamily: Apteronotidae
  • Care requirement: Medium level
  • Color: White and Black
  • Temperament: A bit aggressive
  • Average lifespan: 10-14 years
  • Length: 18-20 Inches
  • Tank requirement: Tropical Freshwater
  • Size of tank: Up to 100 Gal’s
  • Diet: Carnivore

Apart from being called Black Ghost Knifefish, its most common name is scientifically called A. albinfrons

You might be wondering why they have “Ghost” in their name. They have an exciting story behind it. It has been told that a tribe based in South America used to think that all the souls of jungle authorities later transmit into this species. Even some of the extremist people used to worship and ask things from this fish. That’s why they have named “Black Ghost Knife-fish.”

Overall, they have a maximum life span of around 14 years, which is not common in fish species. If you tend to take care of it seriously, they can even cross this age limit. Also, they are capable of gloom at night, especially at deep water levels. They even help to eliminate the darkness for other mates living with it.

Characteristics of Black Ghost Knifefish

Let’s discuss some essential and characteristic details of the species for better understanding.

Typical Behavior:

The black ghost is a nocturnal species that means it likes to stay awake at night. It can quickly look all around in dark water and enlighten some light with a reflection in its size. When they become comfortable with their surroundings, they even start playing with gravels, plants and used them as their hiding spots in the nighttime. They also hunt and gather their food after the evening, which is why their week eyesight. When they get old and lie between 8-10 years, they are significantly less likely to see some objects in the water. They use an electric field to fulfill their necessities.

In the daytime, they are more likely to rest, chill, and roam all-around water. In nature, they are not like Betta fish. Ghost knife may get aggressive sometimes, but it is entirely different from a Betta. If you have 2-3 ghost Knifefish simultaneously in one aquarium or pool, they become possessive and start acting weird. So avoid keeping them together; if you want to have some mates, try other capable companions. 

They appreciate living all alone in a tank as they do not like to interact with other fishes. Most of the time, an early age ghost is most likely to be shy and prefer to enjoy their own company rather than depending on others. 

Please do not place any other stuff around them, because they only like smooth rocks and plants. Extra things make them stressed. 

Also, they are very particular about their diet. If there would be open spaces in their environment, they could live happily, without any anxiety. 



Looks don’t always make you attractive, but here the case is. This is the prime reason behind their high demand all around the regions. The shape is a bit curved and skinny; that’s why known as Knifefish. While moving, they have a broad range of tapers that slowly removes with tail movement. Ghost does not have appropriate fins for the protection of their body. If you look at the upper portion of their body, you will find elegant skinny rages with a thin attached tail. They have white-colored strips with the difference between them.

The black ghost doesn’t have posterior fins in their body; that’s why they are required to atomize momentum through other fins such as anal or humerus. They look fabulous when they trawl their body with fins on swimming. Overall they have different styles of using their fins to expel all the goddess in their surroundings. However, it depends on its mood, like what they desire. We would say that waveform is their best effect that enlightens their beauty.

The fins have covered a broad area, whereas they are not big enough, as their length is. But their entire body support system relies on these fins. The absolute rarity of the species comes from here. But if we don’t look deep inside, they do not have any specific design other than white strips on their bodies. It just is entirely black. Those strips are a bit light in color that makes a difference in their body.

Their nose has again white strips, which look very similar to dolphins. It starts from the nose to their back. It seems super catchy from the far side and makes them unique with other companions. By age, this gets more prominent and enhances the beauty level of black ghost Knifefish.

Unfortunately, this species does not have scales, increasing sensitivity and making them more needed for additional care and diet. These scales are used to protect the body of your fishes; it helps to avoid infections and water diseases, so it’s a considerable lack in it.

However, they are capable of receiving and eliminate electric signals through their organs in the body. The charge is also found in initial organs, where their skin is utilized to make an eligible connection between water and its resistance.

Overall, both genders have identical characteristics, apart from a few. The electric signals are the same as well, whereas the females are more likely to release more frequencies than males.

Black Ghost Knifefish Size:

Usually, the expected size of black ghost Knifefish lies between 16-21 inches maximum. Most of the aquarists misunderstood that ghost knife is small in size. Not only this! Even for other features, people do not have the detailed and correct information.

Black Ghost Knifefish Tank Requirements

Apart from its sensitivity, that black ghost is not easy species, especially for beginner aquarists. In the following, we have mentioned some essential requirements and care factors that you must know about before having a black ghost as your pet.

Black Ghost Knifefish Tank Requirement

Ghost Knifefish Tank Size:

The smallest size requirement of an aquarium for one black ghost Knifefish is 100 Gals. This species is extremely capable of growing large, which is through you must provide them a giant size tank for their convenient growth. Otherwise, they won’t last for long.

Choosing a limited size aquarium for your pet would be highly unjust. Not only would it stop its growth, but it also affects its mental health, depression, anxiety. That can primarily cause infections and pathetic diseases in their glands.

The accurate aquarium size is the structure of your pet’s life quality. Whatever attention you are providing won’t be enough unless the tank size is not appropriate. 100-gallon tank is for only one black ghost knife-fish. 

Water Parameters:

  • Temperature of water: 70-80 degree Fahrenheit 
  • pH in water: 6.2-8.0 (level)
  • Hardness: up to 10 KH 

An average water parameter should lie with lots of flexibility for the reliable life of fishes in the tank. Due to their natural living procedure in the wild, they demand clean water and high quality. You do not set for low or even average rates. You should be very particular as a black ghost has high demands and cannot compromise on them. 

They can get sick, infections on their nose, itchiness on their back, including a high risk of death in the tank. When it comes to black ghost Knifefish, any compromise could result in some serious harm. We suggest you buy some top-notch water testers to keep in check over water quality. But remember to focus on kit quality as well; otherwise, there won’t be an advantage.

Prescribed Food and Diet

The perfect existence for Knifefish is highly identical to what they use to have in their instinctual environment. Disparate to the few most common fish species, this species is inclined to be highly repellant to have conversion in a change of flake or other food items.

Due to such reasons, we will suggest feeding them with what is according to the black ghost Knife fish diet. The black ghost Knife fish lifespan is depending on a high protein-rich and most wild diet.

Any of the go-to lives or frozen foods will make more likely to work great (a variety is always recommended). Bloodworms, prawns, brine shrimp, and tubifex are used by owners daily because they are very natural.

Prescribed Food and Diet


As you have read the entire article regarding black ghost Knifefish, they have a great life span. The best fact is that the species isn’t on the extreme in any conditions. Neither it is highly aggressive neither too calm. Treat them correctly with the most compatible mates if you are keeping them in the home fish tank. Overall, they are straightforward to keep with limited luxurious demands.

Frequently Asked Questions

Is the black ghost Knife fish aggressive?

Most of the time, black ghosts are very calm and peace-loving as they start getting adjusted to the environment. But if you touch them or place some tremendous gravel in the aquarium, they can begin acting extremely annoying, leading to aggressiveness. Avoid placing the same species in the tank or extra small fishes as their mates. Overall, they have an intermediate temperament.

What fish are compatible with a black ghost knife?

We suggest focusing on calm, quiet, and peace-oriented species such as; Cory-doras, discus, angelfish, and related. They would make the best mates with ghost knives to clean the tank environment and don’t produce any awful sounds. Majorly, they do care for other companions in the aquarium at that moment.

Can black ghost Knife fish live with other fish?

Let’s be realistic, that Black ghost loves its vibes; all they want is to chill and relax without depending on any other mate in its surroundings. But on the other side, they do appreciate socializing with a compatible companion. They get irritated from the small size fishes like guppies and Betta. In contrast, when another giant species automatically presents itself to the ghost that becomes much easy to have a comfortable onwards life with their companions.

How can you tell if a black ghost knife is male or female?

There are some minor differences; overall, both male and female black ghost knife-fish look similar. However, if you look at them with detail, the eyes of male fish would be more stretched at the upper surface near the head, whereas the eyes of female fish would be contracted and tested to the lower portion. Overall, their tales are identical, which feels like a rod.

Do black ghost Knife fish eat snails?

According to the characteristic classification, the black ghost is a carnivore species by diet nature, so of course, they eat snails. They are more likely to get active in the nighttime, search insects or snails from the hiding spots, behind the plants, etc.; fish ultimately feeds on them after evening.

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