Black Phantom Tetra: Species Overview

Category: Tetra

Common Names: Black Phantom Tetra

Scientific Name: Megalamphodus megalopterus

Family: Characidae

Minimum Tank Size: 10 Gallons

Care Level: Easy

Temperament: Peaceful

Max Size: 2 Inches

Temperature: 72-82 F

pH: 6.0-7.5

Tank Level: Bottom to Middle

Colors: Black

Diet: Omnivore

Breeding: Moderate

Black Phantom Tetra in Front of Rock

Black Phantom Tetra: Species Overview

Black phantom tetras stand out among the over 150 types of fish in the tetra family. They contain uniquely-shaped fins and interesting markings.

What makes black phantom tetras so popular is that the males perform mock fights, creating a spectacle in the tank without you having to worry about them harming each other.

Fish keepers don’t have to jump through complicated hoops to care for black phantom tetras, making them a good fit for beginners.

However, you must keep their water parameters within a specific range for them to remain healthy. Read on to learn how to do so.

Distinguishing Features

Black phantom tetras have many distinguishing features that make them stand out from the tetra family. But the most popular is the mark behind their gills that looks like an eye.

In fact, black phantoms get the “phantom” in their name because of this marking, which has a black center and bright white sides. The result is that it looks like an eerie but intriguing eye staring back at you.

The black phantom’s “eye” sits on either side of their body. It even has iridescent features, with hints of vibrant blue depending on how the light strikes it.

Aside from this marking, black phantom tetras have a gray base color that can vary in strength according to gender and genetics.

Black phantom tetras have longer fins than certain other tetra varieties. You can also often see black markings framing the edges of the fins on males.

In contrast, females have red hues on many of their fins.

The body shape of these tetras is triangular, and they have a large anal fin that matches well with this fish’s overall flat appearance.

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The black phantom tetra originates in Bolivia, central Brazil, and northern Paraguay, where they live together in large schools.

These fish evolved to have an excellent tolerance for different water conditions.

In the Guaporé River basin of Brazil, they live in mostly clear water. But some other freshwater streams and rivers they live in often contain murky water.

Black phantom tetras gravitate towards slow-moving water that houses an abundance of aquatic plants floating on the water and growing from the substrate. It’s also common for the water’s surface to fill with debris from land-based trees.

Because of this, the substrate in the black phantom tetra’s natural habitat contains a lot of decaying matter. Such organic compounds mix with sand and small pebbles.

However, these tetras tend to live primarily in the middle of the water column, where they shoal in groups between living aquatic plants.


Most black phantom tetras grow between 1.4 and 1.75 inches long.

If you offer them superior nutrition and a large enough tank, you might see them grow as long as two inches. But that’s rare, and it also depends on their genes.

There’s not a significant distinction between male and female lengths. That said, most males have a slimmer profile than females.


Black phantom tetras have a good lifespan of five to six years. So, you can expect them to outlive many other species of tropical fish.

But the quality of care you provide and the lengths you go to create a stress-free tank environment play a crucial role in the lifespan of your tetras.

We’ll share the most important aspects of tank parameters shortly so that you don’t have to undergo a steep learning curve.


Differentiating male and female black phantom tetras is easy, given that males have the following characteristics:

  • Brighter colored “eye” marks on their body
  • Longer, more flowy fins
  • Black edges on fins (often but not always)
  • Slimmer bodies

Furthermore, females have a red hue on the following fins:

  • Adipose
  • Pelvic
  • Anal

While females have a slightly more round appearance year-round than males, you can notice this difference more when she’s preparing to spawn and fills with eggs.


Black phantom tetras have a primarily peaceful temperament.

These fish are notorious for the males showcasing their dominance and social hierarchy by picking a mock fight. But there’s no need to worry when you see this happen—they rarely hurt each other.

Instead, watching a mock male fight is entertaining and alluring. The males often swim in unison, puff out their fins, and hash out their social hierarchy differences in a harmless battle.

Given these mock fights, you might wonder if it would be less stressful on black phantom tetras to keep only one in a tank. The answer is no.

Black phantom tetras are shoaling fish. While this means that they don’t always swim in schools, they enjoy each other’s company and will become depressed if you don’t have enough of their same species in a tank.

So, you should aim to place a minimum of five black phantom tetras in a tank. Having a combination of males and females is vital for their well-being.

As for other fish, these tetras get along well with other peaceful-minded species.

They can be skittish fish, so offering them places to hide in the tank and keeping large and aggressive fish away from them is ideal.

Tank Parameters

If you’re ready to enjoy the unique eye pattern and mock fights that black phantom tetras have, read on to learn how to set up their tank so that these fish will thrive.

Minimum Tank Size

The minimum tank size you should buy for your black phantom tetras is ten gallons for five fish. However, we encourage you to use a 20-gallon or larger tank.

Black phantoms love exploring, so the more space you can offer them, the better their emotional state will be.

It’s best to purchase an aquarium that spans a minimum of 40 inches. Keep in mind that you’ll also need to account for more gallons and space if you include other tank mates with your black phantom tetras.

Water Parameters

You’re now the proud owner of a new tank for your black phantom tetra. Now, it’s time to prepare the water to receive your fish.


As fish that come from a warm climate, black phantom tetras require a water temperature between 72°F to 82°F.

As with all the parameters we cover here, it’s best to aim for the middle of these ranges. Not only will that keep your fish in the best condition possible, but it gives you wiggle room should any of the parameters increase or decrease.


Black phantom tetras err on the side of enjoying slightly acidic water. Their ideal pH range is from 6.0 to 7.5.

That said, they can withstand mild alkaline conditions, given that a neutral pH is 7.0.

You should also monitor the water hardness, as black phantom tetras live well in hardness of 18 dGH or lower, with 10 dGH being ideal.

Testing strips are a cheap and efficient way to check your tank’s pH and hardness levels.


Freshwater fish like black phantom tetras don’t need salt in their tank to thrive. Putting them in a saltwater tank will be detrimental to their health, eventually killing them.

That said, shying away from salt isn’t always necessary.

Aquarium salt has its place in certain freshwater tanks, as it can help strengthen a black phantom tetra’s immune system. Salt is also effective at killing certain parasites and bacteria.

Should you choose to add a small amount of salt to your tetra’s tank, follow the instructions and don’t put more salt than the recommended amount for the size of your tank.

Tank Setup

Admittedly, striking the right balance of water parameters isn’t the best part about being a fish keeper. So, below are the aspects of setting up your black phantom tetra’s tank that will likely excite you more.


The best substrate to use for black phantom tetras is sand, preferably a variety that’s dark brown or black. But fine gravel is also suitable for a substrate.

Using a dark substrate is ideal since it resembles the color your tetras would see in the wild.

Your black phantom tetras won’t venture to the substrate too often, but since these fish enjoy exploring, it’s common for them to take a peek at it occasionally.


Decorations are an excellent item to include in your black phantom tetra’s tank for your fish’s health and to make your aquarium more visually appealing.

Although you’ll find many fancy decorations for purchase online, the reality is that your black phantom tetras will appreciate decor that mimics their natural habitat.

Examples of excellent decorations include:

  • Caves
  • Rocks
  • Driftwood

Remember that your tetras will spend most of their time in the middle of the water column where the water pressure is moderate. Therefore, arranging decorations that reach high enough where your fish will swim is ideal.

That said, decorations can hinder your fish if you place too many of them in their aquarium. Black phantom tetras enjoy exploring in the open water, so they need sufficient space.


A combination of floating and long-stemmed plants that grow from the substrate is vital for black phantom tetra tanks.

Live plants are best, and placing them in thick groups around your tetra’s tank will help block out bright light and give your fish a place to play and hide.

Some excellent live plant choices for black phantom tetras include:

  • Hornwort
  • Water lettuce
  • Java moss
  • Ambulia

As with decorations, leave enough space in the tank for your tetras to swim in the open water.

Black Phantom Tetra with Gravel in Background


Aquarium lights aren’t essential for black phantom tetras. These fish avoid lots of light in the wild, living in areas with aquatic and terrestrial plants to block direct sunlight.

Nevertheless, your black phantom tetras need small amounts of light because they use daylight to manage their circadian rhythms.

Furthermore, many other tropical fish species need medium to bright lighting to stay well.

So, if you have such tank mates for your tetras, you can get around this by ensuring they have enough areas with thick plant vegetation in their tank to avoid glaring lights.


The potential for toxin build-up is a natural part of aquarium ownership. That’s because your black phantom tetras will secrete wastes that can turn into deadly weapons against them if you don’t have a filter equipped to remove them.

Most filters have biological and mechanical functions, although adding a chemical filter is an excellent choice for further removing hazardous wastes in your tank.

Since black phantom tetras live in slow-moving water in the wild, you should select a filter that doesn’t create a lot of water disturbance.

We recommend setting up a schedule to check your filter regularly. Most aquarium filters are low maintenance, but they still require periodic cleaning.


Since black phantom tetras need a water temperature between 72°F to 82°F, purchasing a heater is the best way to maintain this.

Many tank heaters are low-cost and energy efficient.

Be sure to also purchase a thermometer to keep an eye on any potential changes in the water temperature, indicating a malfunctioning heater.


Black phantom tetras are excellent eaters to a fault. If you’re not careful, it’s easy to overfeed them, causing them to gain weight and suffer from the many health issues that can come from it.

These tetras are omnivores. So, you might see them eating some of the live plants in their tank, though you don’t have to worry about them destroying them.

Black phantom tetras also require a significant amount of protein in their diet. Some excellent foods to feed them include:

  • Fish flakes
  • Fish pellets
  • Brine shrimp
  • Bloodworms
  • Mosquito larvae

We recommend using fish flakes or pellets as a base. Then, use shrimp, worms, or larvae as treats.

These protein meals come in live, frozen, or dried forms. Any option is safe to give your black phantom tetras.

You should feed your tetras two or three times per day. Standing by the tank while your fish eat is crucial, as you should let them eat as much as they can in two or three minutes.

After that time passes, use a net and scoop out the remaining food.

With time, you should be able to more easily eyeball how much food your tetras can eat in two or three minutes. But it’s still important to remove excess waste to prevent overeating and toxins from building up in their tank.


You can easily breed black phantom tetras in captivity. You’ll need a separate tank to do so with the following conditions:

  • Dim lighting
  • No substrate
  • pH of 5.5
  • Water hardness of 4 dGH

Then, select the male and female tetras you want to breed, paying attention to their fins, colors, and shapes to produce the best baby fish possible.

The male will eventually begin courting the female, and she’ll release as many as 300 fertilized eggs.

Remove the parent fish from the tank once they spawn. The eggs will hatch within a few days, and you’ll need to maintain the water parameters above to prevent fungal buildup as the fish grow.

Common Diseases

Maintaining the water parameters we discussed here and changing 25% of your tank’s water every two weeks are the best ways to prevent disease in black phantom tetras.

Nevertheless, diseases can still happen, and below are the most common illnesses these tetras get.

Skin or Gill Flukes

Skin and gill flukes are both flatworms caused by the monogenean trematode parasite. These parasites latch onto a black phantom tetra’s scales or gills, causing the fish discomfort and excess mucus production.

Lowering the aquarium temperature and using a mediated bath geared towards flukes is the best way to kill this parasite.

Bacterial Infections

Bacterial infections in black phantom tetras most commonly occur from dirty water. Ammonia poisoning and nitrate poisoning often accompany these bacterial infections.

Black phantoms with bacterial infections might lose their color, develop blood-stained gills, and appear to gasp for air at the top of their tank. Performing a 50% water change, checking the water parameters, and adding salt is vital for trying to heal the infection.


Ich is short for Ichthyophthirius multifiliis, a parasite that burrows under a black phantom tetra’s scales. The result is tetras having many small white spots across their body that itch.

It can be challenging to eliminate ich since it has a hardy life cycle. But frequent 25% to 50% water changes and adding ich medicine in the water can help kill this parasite over time.

Potential Tank Mates

The best tank mates for black phantom tetras are those that have short fins, are of a similar size, and also have a friendly personality.

Since black phantoms spend most of their time in the middle of the water column, choosing top or bottom-dwelling fish is also helpful to give all tank mates space to sprawl.

Some of the best tank mates for black phantom tetras include:

  • Danios
  • Honey gourami
  • Dwarf gourami
  • Apistogramma
  • Freshwater snails
  • Shrimp

Remember, you must first have at least five black phantom tetras living together before adding tank mates to their aquarium.