Black Skirt Tetra
Gymnocorymbus ternetzi
The Black Skirt Tetra (Gymnocorymbus ternetzi) is a semi-aggressive fish that's easy to keep. Give it a tank of at least 75 litres (20 US gallons), water held at 68-81°F, and a pH of 5.8-8.5. Always keep a group of at least 6 - they feel safest in numbers.
Captive lifespan reflects typical experience in a home aquarium, not maximum recorded age; genetics, sourcing, and care vary.
Natural distribution
South America
- South America
Regional colours match the stocking calculator's origin map.
Black Skirt Tetra Tank Setup
Give them a tank of at least 75 litres (20 US gallons). As open-water swimmers they care more about swimming length than height, so a longer tank is ideal. Keep the water at 68-81°F with a pH around 5.8-8.5, and avoid sudden swings. Always keep a group of at least 6 of their own kind - kept alone or in pairs they tend to turn shy, nippy, or wash out in colour.
What Do Black Skirt Tetras Eat?
They're not fussy eaters - feed a varied diet, rotating good-quality dry, frozen, and gel foods rather than the same thing every day, and match the food size to their mouths.
Black Skirt Tetra Tank Mates
Hardy and adaptable but known fin-nipper. Keep in groups of 6+. Avoid long-finned tankmates. The Black Skirt Tetra is semi-aggressive, which is the first thing to weigh up when you choose tank mates. It's a known fin-nipper, so avoid bettas, guppies, and other slow, long-finned fish. It's a shoaling fish, so settle a group of 6 or more of its own kind before adding anything else - a stressed, lonely fish is far more likely to nip or hide. Before you buy, run your full stocking list through our stocking calculator. It weighs temperament, adult size, and water needs together, which a single species page can't do on its own.
Are Black Skirt Tetras Good for Beginners?
Often recommended to beginners, but only after the tank is cycled and you can keep a proper school - not three fish in a new setup.
Black Skirt Tetra - frequently asked questions
What size tank do Black Skirt Tetras need?
Black Skirt Tetras need a tank of at least 75 litres (20 US gallons). A bigger tank is always easier to keep stable, and gives them more room to settle in and behave naturally.
How many Black Skirt Tetras should I keep together?
Keep a group of at least 6. Black Skirt Tetras are a shoaling species and become stressed, lose their colour, or hide when kept singly or in pairs.
What water parameters do Black Skirt Tetras need?
Keep them at 68-81°F with a pH of 5.8-8.5, steady rather than chased to an exact figure. In a cycled tank, ammonia and nitrite should both read 0 ppm, with nitrate kept low through regular water changes.
What do Black Skirt Tetras eat?
Black Skirt Tetras are omnivores and aren't fussy eaters. Feed a varied mix of good-quality dry, frozen, and gel foods, and match the food size to their mouths. Feed small amounts once or twice a day, and remove anything they don't eat.
Are Black Skirt Tetras good for beginners?
Yes - Black Skirt Tetras are a good beginner choice once the tank is fully cycled and you can keep a proper group. They are hardy but still need stable water and a school to feel secure.
Common mistakes with Black Skirt Tetras
- Buying fewer than 6 - Black Skirt Tetras need a proper school to feel secure; isolated individuals hide, fail to colour up, or become stressed.
- Mixing with long-finned fish - Black Skirt Tetras will nip at bettas, angelfish, and other fish with flowing fins, causing stress and infection risk.
Building a community? Run the full list through the stocking calculator before you add anything else.
Great tank mates
Chosen from temperament, overlapping temperature/pH bands, plausible minimum tank footprints, and size versus yours in App-aquatic data. Hobby nuance always wins - verify stocking and temperament before purchasing.
Fish to avoid mixing with Black Skirt Tetras
These well-known species are commonly sold alongside this fish but are not recommended tank mates - verify before purchasing.
- OscarPredator - Oscar will eat or injure smaller tank mates
- Pea PufferPredator - Pea Puffer will eat or injure smaller tank mates
- Betta (Male)Predator - Betta (Male) will eat or injure smaller tank mates
