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Black Skirt Tetra is among the most common species of freshwater fish to keep in an aquarium. These lovely fish boast unique beauty and plenty of personalities to increase the aesthetic appeal of your fish tank. They are readily available almost anywhere, thanks to their popularity.
The best thing is, these aquarium fish are pretty forgiving to mistakes and incredibly easy to take care of, making them perfect for beginners. You won’t even have to do a lot of maintenance to keep them alive, happy, and cheerful either.
Stick with us if you want to learn more about black skirt tetra as we explore everything from black skirt tetra care to breeding!
A Brief Overview of Black Skirt Tetra
|Scientific Name||Gymnocorymbus ternetzi|
|Common Names||Black Tetra, Petticoat Tetra, Black Widow Tetra|
|Lifespan||3 to 5 Years|
|Minimum Tank Size||15 Gallons|
|Temperature Range||70 – 82° F|
|pH Range||6.0 to 7.5|
|Difficulty to Breed||Moderate|
|Compatibility||Compatible with Non-Aggressive Aquarium Fish|
|OK, for Planted Tanks?||With Caution|
Origins and Habitat
Black skirt tetra (Gymnocorymbus ternetzi) is a prominent member of the Characidae family. We will have to travel deep into the South American basins and rivers to find out their origin history.
That’s because these fish originate from the beautiful freshwater rivers of Paraguay, Brazil, and Northeast Argentina, especially the Paraguay and Guapore River basins.
The water in these regions tends to be cool, comfortable, and shaded. That’s how black skirt tetras like their water.
They move in schools and prefer swimming near the surface, feeding on small insects, worms, and crustaceans. Nature seems to have an endless supply of food for them.
However, the black skirt tetra fish you see on the market today do not come from these wild regions, although that’s what happened initially.
Instead, they are bred in captivity for selling by skilled aquarists and aquaculture farms. Some of the variations of this schooling species are genetically modified.
What Does a Black Skirt Tetra Look Like?
Every black skirt tetra comes with that stunning tetragonal shape of the Characidae family that people love so much.
This unique body shape makes black skirt tetras special to many aquarium enthusiasts. Unlike other tetra fish in the Characidae family, they don’t have bright colors.
Instead, they boast a unique gradient color comprised of black, gray, and silver. There is an appealing translucent hue to make them stand out.
A brighter and reflective grayish silver color dominates the front part of the body, especially the head. However, the color gradually fades to a darker shade as it moves to the tail, giving the fish a gradient effect.
The front part of the black skirt tetras tends to be taller than the back. Their tailfin has a forked shape, and it’s pretty thin. The dorsal fin is relatively small too.
Right on the bottom of the fish, you will notice an oversized anal fin. These fins add to the overall beauty of this amazing fish.
Black skirt tetras are known for their small size. In general, they grow up to be 1 to 2.5 inches in captivity. Some may reach 3 inches, but that doesn’t happen as often.
How Long Do They Live?
Black skirt tetras have a relatively shorter lifespan. On average, a black skirt tetra will live for up to 3 to 5 years in a well-maintained tank. They have a slightly longer lifespan in their natural habitat, which is about 6 to 7 years at most.
These fish are affected by the water quality and the overall tank condition. So, their lifespan depends a lot on how well maintained the tetra tank is. You won’t see them hitting that 5-year mark if you don’t care for them properly and allow them to stay in poor water conditions for too long.
To ensure they live long enough, monitor the water conditions, change it whenever it gets too polluted, and ensure optimum feeding. In general, Black Skirt Tetras will live the longest in well maintained planted tanks, where shelter is plenty and stress is low.
Are They Hardy?
Black Skirt Tetras are exceptionally hardy! They are tough fish prepared to fend off more stresses in aquarium life, which is good news for beginners.
Even if you make mistakes while learning the ropes of fish keeping, this fish species won’t give up on you and die like other overly sensitive fish. They can easily adapt to different water parameters. You won’t have to rely on special caring techniques to make sure they survive.
They are very friendly and get along with other fish species with ease. You won’t see them having any trouble competing for food as they are fast swimmers.
Furthermore, they aren’t all that vulnerable to many freshwater fish diseases as they have strong resistance. They rarely get infected. So, you have less to worry about their health. Black skirt tetras have a pretty low mortality rate too.
Just because they are hardy fish doesn’t mean you should give them sub-optimum living conditions, they will stress in poor water conditions and need need optimum water temperature for surviving.
These fish can’t tolerate water that’s too cold or too hot. So, make sure to change the water regularly, use a good filtration system, and keep the temperature above 70°F and below 85°F.
How Do You Tell Male or Female?
It’s easy to tell between a male tetra and a female tetra. Of course, you wouldn’t get it the first time, but it won’t take long to differentiate between the two. The most obvious difference is that a female black skirt tetra is noticeably larger than a male black skirt tetra.
Female black skirt tetras also have a body that’s a bit more rounded than their male counterparts.
You can also tell if the tetra is a male or female by checking the anal fin, although it may be more difficult. Females come with anal fins that run parallel alongside the black stripes on their abdomen.
Besides having a smaller body, male black skirt tetras often feature white spots on their caudal fin. Their anal fins are smaller but broader than females.
As for the dorsal fins, they appear more pointed and a bit narrower.
Can They Live Alone?
Black widow tetra should never be allowed to live alone. Life in solitude for black skirt tetras is nothing short of a nightmare.
This is a schooling fish species and prefers staying in groups. In their natural habitat, these fish school in huge numbers, ranging from hundreds to even thousands! If you want to see the potential of a black skirt tetra school in a large aquarium, check out this cinnmatic from Green Aqua. Green Aqua is one of the best channels for professional aquascaping. I highly recommend subscribing to them!
You can’t expect such a social species to be happy alone, can you? Black Skirt Tetras will become depressed and visibly inactive if you don’t allow them to stay with their friends. Needless to say, they won’t live long.
So, please don’t keep them alone. Add more black skirts to the aquarium. They get along easily with other friendly fish species as they are a pretty and active community fish. Make sure the other fish you add are compatible with each other—more on that in the next section.
What Fish Are Good Tank Mates?
Being shoaling fish, you should at least keep 5 black skirts together in a single tetra tank. The more, the merrier but don’t stuff them in a small space, though. They will be happier, more comfortable, and live longer when kept in a group.
Thanks to their friendly nature, you can freely keep them in a community tank. But be careful when choosing tank mates. It’s easy to pick the right companion, though. Just make sure not to pick aggressive fish because they will bully your precious black skirt tetra.
Also, you don’t want any fin nippers in a black skirt tetras community tank. Tiger barbs and other fin nippers will target their fins and damage them.
Ironically, this species of fish also loves fin nipping so, you should avoid other fish with long fins.
You can keep any peaceful, non-aggressive fish species with black skirts. It’s even better if they are less active than these fishes. Mid and bottom dwellers are also good options.
Here are our recommended tank mates for black skirt tetras.
- Neon Tetras
- Cardinal Tetra
- Celestial Pearl Danio
- Chili Rasbora
- Harlequin Rasbora
- Cory Catfish
- Bolivian Rams
- Honey Gourami
Avoid fish that are slow with large fins like Betta Fish, they are known for nipping their fins.
How Many Should Be Kept Together?
As we’ve mentioned before, black skirt tetras school in huge numbers in the wild. They are incredibly social and thrive the best in groups.
They hate living alone. Ideally, you should keep at least 5 black tetras together. This will allow them to form a community and feel more confident. When it comes to schooling odd numbers tend to do better in aquariums.
If you can add more, that’s even better. Besides, it will be really fun to watch them swim together, play around, and keep the inside of your tank lively and active.
What Do They Eat?
Black skirt tetras in the wild eat whatever they find. From small insects to plants, they will eat all kinds of foods! Similarly, a captive black skirt tetra doesn’t have any special preference. So, you have to decide what you want to feed them. A great staple food to feed them would be Northfin Community Formula.
Feel free to feed them commercially available dry and frozen foods. However, make sure the fish food is rich in nutrients.
Some people like to include live foods in their pet fish diet. These schooling fish seem to be fond of bloodworms, brine shrimp, daphnia, mosquito larvae, etc. The live foods should be fresh and free of harmful bacteria and pathogens. The best way to ensure they are free from harmful pathogens is to culture your own, though that is not for everyone. The frozen food variety is a great choice if you do not want to culture your own live food.
If you are looking for a good ready to feed staple food, I would recommend a pellet food like Northfin community formula. These are pellets that are small enough for nano fish like these tetras while also being free of fillers and high in nutrition. As a rule of thumb, never stick to just one food for your fish. Try to mix it up so they have a well balanced diet.
A well balanced pellet fish that is best for community fish. Small enough for nano fish to eat with high quality ingredients
Tank Requirements and Care
You will appreciate how low-maintenance black skirt tetra is. There are aren’t any complicated requirements that you have to follow.
An entire school of these freshwater fish will easily survive as long as you keep them in the right tank and maintain suitable water parameters. Let’s talk specifics.
Although small in size, they need companions to stay happy. The aquarium size for black skirts should be at least 15-gallons.
But we recommend choosing a 20-gallon fish tank for keeping a small group because these fish are active swimmers and better in a spacious space. Make sure not to overcrowd.
It would be best if you replicated the natural habitat of wild black skirt tetras inside your aquarium. So, the ideal water temperature is anything between 70°F to 82°F. The best temperature would be the middle of this range.
The water should be slightly acidic, like the water bodies in South America. Maintain a pH level of 6.0 and 7.5, and your fish will be just fine. Also, the water hardness should be 5 to 15 dGH. A great way to keep pH and the water on the softer side is to invest in aquarium driftwood.
It goes without said that the water should be clean and pollution-free. So, you should invest in a reliable water filtration system and aquarium test kit to monitor levels.
Plants and Decoration
Your black skirt tetra will feel more at home if the aquarium looks and feels like their natural habitat.
The best way to do that is by adding suitable plants and vegetation. Try adding tall and floating plants because they will provide them with natural shelter, allow them to hide when they get spooked, and darken the environment.
Black skirt tetras mostly keep to the middle and top layer of the aquarium and seldom swim to the bottom. Some great plants to consider investing in that are easy to care for would be:
So, decorating the bottom of the tank isn’t all that important. However, adding a light sandy substrate constant their colors in an aquascape.
Since these pet fish prefer a darker environment, they will be more comfortable using subdued lights.
How to Set Up Your Fish Tank
Setting up your aquarium for black skirt tetras is surprisingly easy. Choose the fish tank size according to the number of fish you’re keeping. If you’re starting small, you work with at minimum a 20-gallon fish tank.
Before adding the water, decorate the aquarium to make it more suitable for black skirt tetra. The goal is to make the inside feel like the water bodies of South America, full of vegetation and life.
Don’t forget to install a quality filtration system. This will keep the water clean longer and allow your fish to stay comfortable and disease-free.
After adding the water, test it to see if the temperature and other water parameters are correct. Move onto the water cycling process if everything is perfect for adding the beneficial bacteria.
That’s about it. The tank should now be ready to be the perfect home for your black skirt tetra!
How to Breed
Breeding black skirt tetra is a bit difficult as it requires a lot of work. They aren’t known for their parental traits, and they don’t have the slightest care for their eggs and fry. In fact, they may even eat their own eggs if given a chance.
That’s why it’s necessary to breed them in a separate breeding tank. The breeding tank should have the same water quality and similar decoration as the main tank.
Additionally, you will have to add java moss, spawning mop, net, or artificial grass. These will keep the eggs out of the reach of the adult fish so that they can’t feast on them. It usually takes 2 years for a black tetra to reach adulthood and be sexually mature.
After setting up the breeding tank, identify the bonded pair and move them into a separate tank. When breeding, feed the pair lots of protein-rich food.
Soon enough, the belly of the female will swell up with eggs. A female black skirt tetra can lay up to 1,000 eggs a day!
The eggs will be scattered all over the place. These eggs are adhesive in nature and stick to the surface. They will sink to the bottom slowly and stick to the java moss, spawning mop, or the net that you’ve laid out before.
When the breeding process is complete, quickly remove the adult fish from the breeding tank before they start eating the eggs.
It usually takes 24 to 36 hours for the eggs to hatch. After hatching from the eggs, the fry will feed on the egg sac.
Wait out a couple of days, and they will be ready to eat fry foods. After the next few weeks, they will grow up to be able to eat baby brine shrimp. Don’t move them into the main tetra tank until they are big enough.
If you want a new video explanation and video, here is a great video by Mark’s Aquatics explain his process.
Black skirt tetras are highly recommended for beginners, but seasoned aquarists can get them too. These fish are pretty fascinating in appearance and fun to have in your community aquarium.
Leave us a comment below if this information was helpful or leave it at that, we don’t mind either way. Who knows, maybe one day soon we’ll be helping get your future tanks set up too!
Mark is the founder of Aquarium Store Depot. He started in the aquarium hobby at the age of 11 and along the way worked at local fish stores. He has kept freshwater tanks, ponds, and reef tanks for over 25 years. His site was created to share his knowledge and unique teaching style on a larger scale. He has worked on making aquarium and pond keeping approachable. Mark has been featured in two books about aquarium keeping – both best sellers on Amazon. Each year, he continues to help his readers and clients with knowledge, professional builds, and troubleshooting.