Black Phantom Tetra: Unveiling a Captivating Tank Addition

Charlie Morton

Charlie Morton


Black Phantom Tetra

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Tetras are the bread and butter of tropical community tanks. But if there’s one species in the family that’s under-represented, it could well be the black phantom tetra.

With an elegant, oval shape, peaceful character, and entertaining, active behavior, black phantoms deserve to be kept far more often than they are.

Let’s take a closer look at how to keep one of the most under-appreciated tetras in the aquarium hobby!

Black Phantom Tetra at a Glance

Black Phantom Tetra Info
Other Common NamesBlack Phantoms
Scientific NamesMegalamphodus megalopterus, Megalamphodus rogoaguae, Hyphessobrycon megalopterus
OriginParaguay, Brazil, Bolivia
Adult Size2 inches
Minimum Tank Size20 gallons
TemperamentMostly peaceful, but may nip fins
Tank LevelMid-dweller
Lifespan5 years
DietOmnivore, especially enjoys meaty foods
BreedingEgg scatterer
Care LevelBeginner - Intermediate
Water pH5.0 to 7.5
Water HardnessUp to 18 dGH
Water Temperature70 to 82 F (22 to 28 C)

Species Overview

Origin and Background

Like other tetra species in the Megalamphodus genus, black phantom tetras come from the soft, acidic waters of South America. A widespread species, they can be found in a variety of river habitats in Paraguay, Brazil, and Bolivia.

While many of these rivers are heavily vegetated blackwater habitats, this species can also be found in clearer, more open waters in some parts of the region.

Although they are still abundant in their wild habitats, most aquarium stocks today are captive-bred rather than wild-caught.

Size and Appearance

Black phantom tetra don’t have the brilliant colors of some of their relatives, but they do boast a highly attractive, elegant shape and demeanor.

Their disc-shaped bodies are silvery gray with beautifully prominent dark fins. The dorsal fins are particularly long and striking, especially when erected by males when jostling for hierarchy.

Black phantoms earn their name from the curious ‘false eye patch’ behind their gills. Composed of a large white spot with a vertical black dash down the middle, they might make you imagine a phantom is looking back at you.

This tropical fish usually grows up to around 1.75 inches, but can occasionally reach 2 inches in length.

Sexual Dimorphism

Male phantoms have longer fins than females, which are lacking in any red pigments.

Females have deeper bodies than males and sometimes exhibit attractive red-tinted pelvic, anal, and adipose fins. This reddish color sometimes extends to the mid-body, but they shouldn’t be confused with the similarly-shaped ‘red phantom tetra’.

Black Phantom Tetra Care Guide

Tank Size

While some guides suggest a 10-gallon tank is big enough for this fish, I would strongly advise keeping them in such cramped conditions.

All tetras really need a tank of at least 20 gallons with the largest possible surface area to exhibit proper schooling behavior. In tanks smaller than this, they’ll feel restricted and ‘hover around’ rather than moving around the tank as a unit.

Smaller tanks are also more prone to water quality issues and tight spaces can also encourage fin-nipping behavior. Because black phantoms are so active, I’d even suggest that a 30-gallon tank is much better than a 20-gallon equivalent.

Tank Environment

Black phantom tetras will be happiest when you replicate their natural habitat within your fish tank. Although they come from a variety of habitats in the wild, they look especially alluring in a heavily planted tank with subdued lighting.

Plants and Decor

A mixture of plants in the substrate and a few floating plants will provide a very beautiful and comfortable habitat for this fish.

Java fern, Java moss, Amazon Sword, Anacharis, Anubias, Crypts, and Vallisneria are all easy plants that are perfect for beginner aquarists and experts alike.

Floating plants like Amazon frogbit, water hyacinth, and water sprite offer shelter at the water’s surface and provide dappled shade underneath, which black phantoms seem to enjoy.


Black phantoms are often found in ‘black water’ habitats in the wild. These niches are termed ‘black water’ because the water is stained a dark amber color from the presence of dissolved tannins. Tannins are released from materials such as fallen tree leaves, driftwood, and peat and turn the water softer and more acidic.

By adding Indian almond leaves, aquarium-safe peat, or untreated hardwood such as beech and oak to the tank, tannins are released into the water. Imbuing it with an amber hue, the tannins adjust the water chemistry in favor of ‘black water fish’ like black phantoms.

Important tip!: If you do wish to create a black water aquarium, you’ll need to remove your carbon filter, to prevent it from removing the tannins from the water.


While these tetras would often inhabit rivers with a muddy or sandy substrate, soft substrates are more difficult to maintain and more challenging to grow plants in.

Because this species doesn’t dig, a gravel substrate remains the best choice for most people keeping this fish.


The tannin-stained, heavily vegetated waters that phantoms often inhabit in the wild let less light penetrate than clear water. That means these fish are well-adapted to subdued light levels and, interestingly, dim lighting can even make them look more stunning.

The subtle iridescent fins and scales of black phantoms become mysteriously more vivid and pronounced in low lighting, meaning that a shady environment can be beneficial for both you and your fish!

Floating plants are ideal for creating shade – just make sure enough light penetrates for healthy plant growth underneath.

Tank Lid

Black phantoms are small but powerful fish that can easily leap out of the water and land on the floor if there are any gaps in the tank lid!

Keep a tight-fitting lid on the tank at all times – it will also help to conserve heat.

Water Temperature

Because they’re found over a large area in South America, black phantoms can tolerate a wide range of water temperatures.

The most southerly populations of these fish can tolerate water temperatures down to 68°F, meaning they could just about be kept in a warm room without an aquarium heater.

In most situations, however, I’d recommend keeping them in a heated tank with the thermostat set between 72-82°F.

Also, note that tolerating a wide range of temperatures doesn’t make these fish immune to thermal shock. Acclimatizing them properly in a new tank and avoiding temperature fluctuations is just as important as it is with other types of fish.

Water Parameters

In the wild, black phantoms inhabit soft, acidic waters with a pH between 5.0 and 6.5.

Most aquarium stocks, however, are captive-bred and will tolerate water with a pH of up to 7.5. Try to keep general water hardness below 20 dGH.


Excellent water quality is one of the most important aspects of keeping these fish healthy, so an efficient aquarium filter is essential.

Hang-on-back filters and internal power filters are the best options for tanks of up to 55 gallons. For larger tanks, you could consider a canister filter.

Because they come from slow-moving rivers, black phantoms can get stressed by a strong filter output. To reduce the water current without compromising the filter’s efficiency, I recommend using an aquarium spray bar, or lily pipe.


Black phantom tetras may be omnivorous and unfussy in their eating habits but they’ll do much better when given regular helpings of meaty treats in their diet.

As a staple food, high-quality flake foods are a good choice. Supplementing this with high-protein fresh and frozen foods at least a few times a week or even on a daily basis will help these fish to remain healthy and also look more attractive.

Bloodworms, tubifex worms, daphnia, brine shrimp, and mosquito larvae are all good choices.

As usual, feed your fish twice a day, with no more than they can eat in 2 minutes. Overfeeding is one of the most common causes of water quality and health problems in aquarium fish. Even if your fish seem hungry, be careful not to feed too much!


Black phantoms are extremely active fish that love to swim in the middle layers of the aquarium. They display interesting social behavior, including light-hearted jousting between males.

Are Black Phantom Tetras Aggressive Fish?

Black phantoms are generally very peaceful fish that will neither harm one another, nor other species in the aquarium.

Males do have a social hierarchy, however, and will spar with each other to establish dominance. These playful scuffles rarely result in any harm or injury but can reduce lifespan through stress if sparring becomes excessive.

Like other tetras, black phantoms may very occasionally nip the fins of other fish if they feel stressed. Yet more good reasons for keeping these fish in larger tanks!

Minimum School Size

To make sure they feel secure and relaxed, always keep black phantoms in schools of at least 6 fish.

Compatible Tank Mates

The dark colors of black phantoms look especially stunning when set against other fish with brighter colors.

Neon tetra, cardinal tetra, lemon tetra, ember tetra, and Congo tetra all make great candidates from the tetra family. Brightly colored livebearers like platies and swordtails will also make a good match as long as the water chemistry is not too acidic.

Because they’re fairly fast and agile, black phantoms can also be kept as a dither fish alongside medium-sized, semi-aggressive species like cichlids, and gouramis.

Choosing some bottom-dwelling species will also add diversity to the tank, and these species also often help to keep the tank clean. Kuhli loaches, corydoras catfish (cories), bristlenose plecos, and aquarium shrimp like cherry shrimp and Amano shrimp make good choices.

Health and Disease

Black Phantom Tetra

Black Phantom tetra demand excellent water quality and may develop health problems and diseases if water conditions deteriorate or they become stressed.

Ich, velvet, and flukes are all common parasitic diseases that can lie dormant in an aquarium for years until a weakened fish or very poor water quality offers them a chance to strike.

Similarly, bacterial and fungal infections like columnaris and water molds only tend to affect fish that are already in a vulnerable state.

Keeping black phantom tetras in groups of 6 or more, with plenty of hiding places in a clean tank, is therefore the best defense against stress and unnecessary diseases.


Black phantom tetras are not particularly difficult to breed if you get the tank conditions right. A separate breeding tank with sponge filters and excellent water quality are essential for success.

  • To trigger spawning, you need to remind these fish of their natural environment as fully as possible.
  • Condition the parents by feeding them live foods like blood worms, black worms, mosquito larvae, and brine shrimp. Only use frozen equivalents if these are unavailable. Floating plants are advisable to reduce light intensity.
  • Water chemistry must be soft (below 6 dGH) and acidic (below pH 6.2) to induce spawning. Add tree leaves such as beech leaves or Indian almond leaves to release tannins. These also will grow infusoria that will later feed the fry.
  • When preparing to spawn, the male fish may chase females and jostle for hierarchy, displaying impressive erect fins. Females lay up to 300 eggs which are scattered over the aquarium.
  • Remove parent fish immediately after spawning to prevent them from eating their eggs.
  • The fry hatch quickly and need dim lighting and immaculate water conditions to thrive. If you’ve added leaf litter, let them feed on the natural infusoria for the first week. After that, feed on baby brine shrimp, followed by crushed flake food.


Like most other types of tetra, black phantoms have a relatively short lifespan. If kept in good conditions without chronic stress, they can live for up to 5 years.

As mentioned earlier, constant bickering between males can shorten their lifespan, hence the need for a spacious tank to reduce fighting.

Tank Maintenance

Some top tips for keeping your black Phantom Tetra in tip-top condition!

  • Install a good filter and clean it every 2-3 weeks.
  • Vacuum your substrate and make partial water changes of 20-35% every 1-2 weeks with treated water of matching temperature.
  • Get yourself a reliable heater and thermometer. Make daily checks to ensure the temperature is within the ideal range for all of your fish.
  • Observe your fish closely every day to ensure they are in good health and interacting peacefully with each other.
  • Test your aquarium’s water at least once a month or any time your fish seem unwell. Keep nitrate levels below 20 ppm.

Buying Guide

Black phantoms are not as popular as some other tetras but they still turn up regularly in pet stores.

If you’re buying your fish from a store, only choose active individuals, with bright colors, shiny eyes, and healthy-looking fins. If you’re buying online, always check reviews to ensure the site’s integrity.

Expect to pay between 3-7 US dollars per fish in 2023.

Final Thoughts

Black phantom tetra are extremely elegant, beautiful, and fascinating community fish. Their relatively peaceful nature and robust character make them an excellent choice for a wide range of community tank setups.

If you’ve enjoyed learning about black phantoms, you might also be interested in another tetra with a similar shape and coloration. Learn all about keeping the ever-popular black skirt tetra here!

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