Skip to Content

The Only Guide To Black Skirt Tetra Care You Need

The Only Guide To Black Skirt Tetra Care You Need

Not many fish are able to stand out in the same way as black skirt tetras – not for their bright colors but rather for the lack of it. 

Yes, these fish can give your aquarium that dark contrast that can complement its colorful tank mates and the greens in your tank. But this isn’t the only reason behind their rising popularity. 

So, what’s the deal with these neon tetra’s gothic cousins? Let’s explore together and learn all there is about their care, temperament, and breeding!

Breed Overview

black skirt tetra breed overview table chart

Black skirt tetra (Gymnocorymbus ternetzi) is one of the most common types of tetras you can find. Yes, even though they might not look like it, they are related to colorful neon tetras that have probably lived at least once in your tank.

These fishies originate from South America – most notably, Northeast Argentina, South-Central Brazil, and Paraguay. However, you can find them in other areas of the continent, as well.

Also known as the black widow tetras, high-fin black tetras, blackamoors, petticoat tetras, or simply black tetras, these fish have become a common sight in pet stores. This is due to the combination of their pretty looks and ease of care.


black skirt tetra fish

At first glance, you might think black skirt tetras are more closely related to tiger barbs than to most other tetra species. They look nothing like some other popular tetra species you might’ve seen! 

These fish actually belong to the characidae family, so they have the tetragonal shape they share with their close cousins. The front of their body is fairly tall, but it narrows as it gets closer to the tail. 

Their very long fins only make their entire look more dramatic. In fact, their dorsal, anal, and caudal fin might make this tetra look as if it’s wearing a dress or a skirt. You’ve guessed it – this is partly how it got its name.

Next to the forked caudal fin and long and pointed anal fin, their dorsal fins might appear unnoticeable. 

Another unusual trait is this fish’s color. Black skirt tetras come in silver to dark gray shades that might appear a bit lighter due to their translucency. 

The gray color seems to become darker on the second part of the fish’s body, with the head and chest being the brightest part. 

They also have two vertical black stripes. Sometimes, a third one going over the fish’s eye might be noticeable, as well. 

When it comes to their fins, they are typically black or dark gray and translucent – with the exception of a lighter-colored dorsal fin. Some might have barely noticeable rays, but you’ll really have to look for them to notice them.


Black skirt tetras are not big fish, although they are far from being the smallest tetras out there. 

In general, adults reach around 3 inches in size. Some of mine have managed to reach 3.3 inches, but it’s rare for them to grow larger than that.

Many times, black skirt tetras will stay much smaller. The main reasons behind this are improper care and bad genetics. 

Unfortunately, if you’ve bought an adult fish, there is nothing you can do to increase its size. However, just because they are smaller doesn’t necessarily mean that they’ll have a bad quality of life! 

Temperament And Behavior

Another reason why these fishies are so popular is their amazing temperament.

Black skirt tetras are known to be social butterflies, constantly swimming and interacting with their fellow tank mates. They are an entire opposites of crowntail bettas behavior-wise!

They are generally peaceful and friendly, making them a great addition to community aquariums. They are curious fish that love to explore their surroundings, so you’ll often find them playing hide-and-seek among the plants and decorations.

As these tetras are highly social, they are often found swimming in small groups. They engage in playful behaviors, such as chasing each other or performing swimming routines that will surely captivate anyone that looks at your tank.

It’s worth mentioning that black skirt tetras can be a bit shy when introduced to a new environment. But with time and patience, they’ll quickly acclimate and become more comfortable in their surroundings. 

Are Black Skirt Tetras Aggressive?

Black skirt tetras are not aggressive. In fact, they are some of the most peaceful tetras out there, and that means a lot!

However, they might exhibit some fin-nipping behaviors if you pair them with other long-finned fish, such as angelfish. 

This isn’t due to aggression, however. It’s just their natural instincts kicking in!

Health Problems

Black skirt tetras are healthy fish overall. However, just like any other aquatic pets, they may encounter a few health issues. 

One common issue is ich, also known as white spot disease. This pesky parasite can cause small white dots on their bodies. 

Fortunately, treating Ich is relatively simple with medications and by adjusting the water temperature. You might also try adding some aquarium salt or one of its substitutes – or you can even try making your own!

Another concern is fin rot, which can occur due to poor water conditions or stress. Unfortunately, this disease can go unnoticed for a while, especially if you think the reason why your fish’s fins are decaying is due to fin-nipping.

Black Skirt Tetra Lifespan

When it comes to the lifespan of black skirt tetras, we can expect them to be with us for a good few years. On average, these little fishies live around 3 to 5 years.

Now, it’s important to note that the lifespan of black skirt tetras can be influenced by various factors. This includes their health, but also their genetics.

This is why it’s essential to make sure you’ve bought your fish from good sellers and stay away from rare morphs. 

Care Guide

black skirt tetra in planted aquarium

One of the most important things you need to be aware of before you decide to buy black skirt tetras is how to care for them properly. 

Luckily for all of us, these are amazing beginner-friendly fish. They are rather hardy and can survive in many water parameters. However, if you wish for them to thrive, you need to provide them with an environment that resembles their natural habitat

These are the guidelines to follow:


When it comes to mealtime, black skirt tetras are not picky eaters. They are omnivores, meaning they enjoy both plant-based and protein-rich foods.

To keep them happy and healthy, it’s best to provide a varied diet

Store-bought foods are always a safe option. This includes high-quality flakes or pellets specifically formulated for tropical fish. These foods often contain a good balance of nutrients formulated especially for these fish.

In addition to dry foods, black skirt tetras might appreciate the occasional treat. Brine shrimp, bloodworms, daphnia, and even small insects are all delicious options that can complement their feeding routine.

Just remember – It is never okay to catch insects and give them to your fish! If you do, you are risking poisoning.

As they are omnivores, consider including some plant matter in their diet. They enjoy nibbling on blanched vegetables like spinach or zucchini

Remember to feed them in small amounts a few times a day, as overfeeding can lead to health issues and poor water quality

If you notice there are plenty of food leftovers about half an hour after you’ve fed them, this means you’ve given them too much. Remove the food remains and remember to give them smaller amounts next time.

Tank Size

As for the tank, it doesn’t matter that much whether you choose an acrylic or a glass one. What does matter is the size.

While black skirt tetras are not large fish, they prefer living in schools. Each new fish increases their space demands.

For a small group of black skirt tetras, a tank with a capacity of 15 gallons or more is recommended. This size allows them to have enough room to swim freely.

Of course, if you can provide them with a larger tank – do it. A larger tank not only accommodates their energetic nature but also helps maintain stable water conditions more easily.

Water Parameters

Creating the perfect living environment for black skirt tetras also involves maintaining specific water parameters. 

As I’ve already mentioned, these fish can survive many conditions. This doesn’t mean you shouldn’t provide them with the best care possible. 

Black skirt tetras thrive in water that is comfortably warm, ideally between 78°F and 82°F. Anything lower than that might affect their health and immunity.

These friendly fish prefer slightly acidic to neutral water conditions. Aim for a pH level between 6.5 and 7.5 to keep them happy and thriving. 

Black skirt tetras are adaptable to a range of water hardness levels, but they generally prefer moderately soft to slightly hard water. Aim for a dGH level between 5 and 15 to maintain their optimal habitat.

It’s important to note that stability is key when it comes to water parameters. Rapid fluctuations in temperature, pH, or hardness can stress the fish and lead to health issues. 

Regularly testing and monitoring the water parameters, while making gradual adjustments when necessary, will help create a stable and suitable environment for your black skirt tetras. Keep your water testing kit nearby at all times!

And don’t worry – you can clean the fish tank without removing the fish. Regular water changes will not affect your tetras, so there are no excuses.

Water temperature:Between 78°F and 82°F
pH levels:6.5 – 7.5
Water hardness:5 – 15 dGH


Just because a fish is resilient doesn’t mean you don’t need to provide them with a filter. This is a mandatory part of equipment for all aquatic pets, and this includes black skirt tetras.

Filters play a vital role in maintaining water quality by removing debris, waste, and harmful substances from the aquarium. For black skirt tetras, a reliable and efficient filter is necessary to keep their home clean and their fins fluttering with joy.

There are various types of filters available, including hang-on-back (HOB) filters, canister filters, and sponge filters. Each type has its benefits, but it’s important to choose one that suits the size of your tank and provides adequate filtration capacity.

Personally, I prefer using sponge filters as these suit my tank the best. They are also a good choice for smaller pets that might be used as tank mates.

Whichever type you choose, ensure that the filter provides mechanical and biological filtration. Mechanical filtration removes physical debris, while biological filtration helps establish a beneficial bacteria colony that breaks down harmful substances in the water.

Regular maintenance of the filter is also important. Clean or replace filter media as instructed by the manufacturer to prevent clogging and maintain optimal performance.

Remember – a filter is not a replacement for a proper nitrogen cycle. Even if you have the best filter in the world, you shouldn’t add fish before the nitrogen cycle is completed.

Light Requirements

black skirt tetra in planted fish tank

Black skirt tetras don’t have any specific lighting requirements, but they do appreciate a natural day-night cycle. A regular light schedule of 8 to 10 hours of light followed by 14 to 16 hours of darkness helps mimic their natural environment.

It’s important to achieve balance with the intensity of the light. Avoid excessive brightness or intense direct lighting, as it may cause stress or discomfort for the tetras. Opt for a moderate light intensity that provides a gentle and diffused illumination throughout the tank.

Also, keep in mind that black skirt tetras don’t need sunlight. Quite the opposite – such a bright light can cause more harm than good.


Despite common misconceptions, most aquarium fish do need substrate. This includes black skirt tetras.

Black skirt tetras are quite flexible when it comes to substrate options, and you have a variety of choices to suit their needs. 

A favorite choice of mine is fine gravel or sand substrate. However, you don’t need to spend too much time thinking about this. These fish are not bottom dwellers, so they won’t care too much about the type of substrate you provide them with.

When setting up the substrate, it’s important to rinse it thoroughly before adding it to the tank. This helps remove any debris or dust that might cloud the water.

When changing the water, use this opportunity to clean the fish tank gravel. From vacuuming to rinsing it, there are many helpful methods that can help you keep your black skirt tetra tank clean!


As black skirt tetras are active and shy fish, they need plenty of decorations to keep them happy.

Rock caves are excellent additions to the aquarium for black skirt tetras. These little fish love exploring and seeking shelter, and rock caves provide them with great hiding spots.

When choosing rock caves, opt for smooth rocks without sharp edges to avoid injury to your fish. As these tetras have long and delicate fins, they can easily harm themselves if the caves are made improperly.

Ensure that the rocks are securely positioned in the tank to prevent accidental collapses.

In addition to rock caves, you can also consider other tank decorations like driftwood, artificial plants, or ceramic ornaments

These additions provide additional hiding places, create a more natural-looking habitat, and offer opportunities for exploration and play for your tetras.

Just keep in mind that some decorations might mess with water parameters. For example, driftwood is often used for lowering pH levels in the tank. If this isn’t something you want to happen, make sure to boil it beforehand.

Live Plants

If you love keeping live plants in your tank, I have some good news for you. Your black skirt tetras will love them! In fact, live plants offer numerous benefits for both the fish and the overall ecosystem of the tank.

Having live plants in the aquarium provides a natural and aesthetically pleasing environment for black skirt tetras. These plants mimic their natural habitat and create a sense of security for the fish. Not just that, but live plants offer several advantages for black skirt tetras. 

First off, they provide additional hiding spots and resting places, allowing the tetras to retreat and feel safe. 

The plants also contribute to the overall well-being of the fish by improving water quality. They help absorb nitrates and other waste products, reducing the risk of water pollution and creating a healthier environment.

Furthermore, live plants help create a balanced ecosystem in the tank. They contribute to oxygenation, which is essential for the well-being of the fish, and they can provide natural food sources for the tetras. 

Some plants, like Java moss or floating plants, also offer the tetras a place to lay their eggs during breeding – although I still advise you to keep the breeding process inside a 40-gallon breeder tank.

Black Skirt Tetra Tank Mates

As black skirt tetras are very friendly fish, I would always recommend keeping them in a community tank. Fortunately, choosing proper tank mates for these fishies is rather easy, and there are just a few things to think about.

It’s important to select fish that will coexist peacefully and create a harmonious community in the aquarium. Here are some of the good options:

  • Other tetra species: Black skirt tetras often do well with other tetra species like neon tetras, glowlight tetras, or cardinal tetras. Also, these fish share similar water requirements.
  • Peaceful community fish, such as rasboras, dwarf gouramis, platies, and guppies.
  • Bottom-dwelling fish, such as corydoras catfish or bristlenose plecos, can be a great choice. Many of these fish are also a part of the clean-up crew.
  • Peaceful snails and freshwater shrimp, like nerite snails or cherry shrimp can be interesting additions. They help keep the tank clean and add an extra touch of diversity to the ecosystem.

Of course, some fish species are to be avoided. This includes aggressive fish, such as kribensis cichlids, tiger barbs, or king crowntail bettas.

Avoid other fin-nippers, as these might love to chase black tiger barbs and their long tails. Also, keep them away from fish that are significantly faster or more active than black skirt tetras, as these might cause stress.

How Many Black Skirt Tetras Should Be Kept Together?

As these are social fish that prefer to live in groups, it’s recommended to keep them in schools of at least 6 individuals or more. By keeping them in a group, you mimic their natural behavior and provide a more comfortable and secure environment for them.

When black skirt tetras are kept in smaller numbers or as single fish, they may become stressed, less active, and even get sick.

Having a larger group also lowers the chances of aggression – no matter how slim they might be in the first place.

Black Skirt Tetra Breeding 

Black skirt tetras are fairly easy to breed in captivity. In fact, this is how most of these fishies sold at pet stores are born. 

The most challenging part of the breeding process is differentiating between male and female tetras. These two look almost exactly the same!

Male black skirt tetras seem to be a bit more slender, with pointer fins, and they might be darker in color. Also, they might become a bit territorial and more active during the breeding season.

Females, on the other hand, tend to have shorter dorsal and anal fins and they might be a bit more rounded. However, these differences are hardly noticeable, so most of the time you will combine a bunch of black skirts and hope for the best.

To encourage breeding, provide a separate breeding tank with plenty of plants for egg-laying. While the breeding process might happen in the main tank, you should avoid this for several reasons. 

First, adult fish might eat the eggs and the fry, lowering the chances of your fish growing to adulthood. 

Another issue is that changing the water parameters to suit the breeding requirements might not sit well with other tank inhabitants.

Maintain the water temperature near 80°F and provide a soft, acidic environment. The male will display courtship behaviors, and the female will scatter adhesive eggs among the plants. 

After spawning, remove the adult fish to prevent them from eating the eggs. The eggs will hatch in a few days.

The Bottom Line

Black skirt tetras might not be as colorful as some other aquatic pets, but there is no reason why you shouldn’t like them!

They are beautiful, easy to care for, and they are among the friendliest fish you can get. This makes them some of the most ideal fish for beginners.

Just keep in mind that, just because a fish can survive in bad conditions, doesn’t mean you should let it suffer. Provide it with the best care possible so your pet can live a long and happy life.