Photo: Luis Miguel Bugallo Sánchez (Lmbuga) Copyright: GFDL (GNU Free Documentation License) Publicada por/Publish by: Luis Miguel Bugallo Sánchez (CC BY-SA 3.0) — via Wikimedia Commons
Black Skirt Tetra (Gymnocorymbus ternetzi)
A tough, school-minded tetra with dramatic trailing fins — the beginner's gateway to the characin family.
Will it live with a Black Skirt Tetra?
We compare each fish against your black skirt tetra on temperament, size, water parameters and swimming zone. Set your tank size and filter the results.
- Adolf's Cory✅ CompatiblePeaceful · 5.5 cm · Medium care · 22–26 °C (72–79 °F)
- Semi-aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Adolf's Cory in a shoal of 6+ or it gets stressed and nippy.
- Agassiz's Corydoras✅ CompatiblePeaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
- Semi-aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Agassiz's Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Axelrod's Cory✅ CompatiblePeaceful · 5 cm · Easy care · 23–28 °C (73–82 °F)
- Compatible on the things that matter: shared water near 23–26 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Axelrod's Cory in a shoal of 6+ or it gets stressed and nippy.
- Bandit Corydoras✅ CompatiblePeaceful · 5 cm · Easy care · 22–27 °C (72–81 °F)
- Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 22–26 °C — no size, zone or temperament conflicts.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Bandit Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Blood Red Tiger Pleco✅ CompatiblePeaceful · 6 cm · Medium care · 24–29 °C (75–84 °F)
- Semi-aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Blue Turbo Snail✅ CompatiblePeaceful · 5 cm · Medium care · 25–30 °C (77–86 °F)
- Semi-aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Butterfly Hillstream Loach✅ CompatiblePeaceful · 6 cm · Hard care · 18–24 °C (64–75 °F)
- Compatible on the things that matter: shared water near 20–24 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Celebes Rainbowfish✅ CompatiblePeaceful · 7 cm · Medium care · 22–28 °C (72–82 °F)
- Semi-aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Celebes Rainbowfish in a shoal of 6+ or it gets stressed and nippy.
- Corydoras Catfish✅ CompatiblePeaceful · 6.5 cm · Easy care · 22–26 °C (72–79 °F)
- Compatible on the things that matter: shared water near 22–26 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Corydoras Catfish in a shoal of 6+ or it gets stressed and nippy.
- Costa's Tetra✅ CompatiblePeaceful · 7 cm · Easy care · 22–28 °C (72–82 °F)
- Compatible on the things that matter: shared water near 22–26 °C, workable temperaments, and no predator-and-prey size gap.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Costa's Tetra in a shoal of 6+ or it gets stressed and nippy.
- Duplicareus Corydoras✅ CompatiblePeaceful · 5.5 cm · Medium care · 23–27 °C (73–81 °F)
- Semi-aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Duplicareus Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Elegant Cory✅ CompatiblePeaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
- Semi-aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Elegant Cory in a shoal of 6+ or it gets stressed and nippy.
- False Julii Corydoras✅ CompatiblePeaceful · 6 cm · Easy care · 22–26 °C (72–79 °F)
- Semi-aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep False Julii Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Hillstream Loach✅ CompatiblePeaceful · 6 cm · Hard care · 20–24 °C (68–75 °F)
- Semi-aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Horseman Cory✅ CompatiblePeaceful · 5 cm · Medium care · 22–26 °C (72–79 °F)
- Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 22–26 °C — no size, zone or temperament conflicts.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Horseman Cory in a shoal of 6+ or it gets stressed and nippy.
- Narcissus II Cory✅ CompatiblePeaceful · 5.5 cm · Medium care · 22–26 °C (72–79 °F)
- Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 22–26 °C — no size, zone or temperament conflicts.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Narcissus II Cory in a shoal of 6+ or it gets stressed and nippy.
- Panda Loach✅ CompatiblePeaceful · 6 cm · Hard care · 18–23 °C (64–73 °F)
- Semi-aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Peacock Gudgeon✅ CompatiblePeaceful · 7 cm · Medium care · 22–28 °C (72–82 °F)
- Semi-aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Peppered Corydoras✅ CompatiblePeaceful · 7 cm · Easy care · 18–26 °C (64–79 °F)
- Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 20–26 °C — no size, zone or temperament conflicts.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Peppered Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Rust Corydoras✅ CompatiblePeaceful · 5.5 cm · Easy care · 23–27 °C (73–81 °F)
- Compatible on the things that matter: shared water near 23–26 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Rust Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Slate Corydoras✅ CompatiblePeaceful · 6 cm · Medium care · 23–28 °C (73–82 °F)
- Semi-aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Slate Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Spotfin Corydoras✅ CompatiblePeaceful · 6.5 cm · Easy care · 22–26 °C (72–79 °F)
- Semi-aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Spotfin Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Spotted Corydoras✅ CompatiblePeaceful · 7 cm · Easy care · 22–27 °C (72–81 °F)
- Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 22–26 °C — no size, zone or temperament conflicts.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Spotted Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Sterbai Corydoras✅ CompatiblePeaceful · 6.5 cm · Medium care · 24–30 °C (75–86 °F)
- Semi-aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Sterbai Corydoras in a shoal of 6+ or it gets stressed and nippy.
- Black Ruby Barb⚠️ With cautionSemi-aggressive · 6 cm · Easy care · 22–26 °C (72–79 °F)
- Both are a bit pushy (semi-aggressive + semi-aggressive) — workable only in a larger tank with cover and broken sight lines.
- Your 75 L tank is below the ~100 L this pairing really wants — crowding raises aggression.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Black Ruby Barb in a shoal of 6+ or it gets stressed and nippy.
- Blackline Rasbora⚠️ With cautionPeaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
- Expect Black Skirt Tetra to harass Blackline Rasbora at times; give dense cover and watch them at feeding.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Blackline Rasbora in a shoal of 6+ or it gets stressed and nippy.
- Desert Goby⚠️ With cautionSemi-aggressive · 6 cm · Easy care · 18–28 °C (64–82 °F)
- Black Skirt Tetra and Desert Goby can both be territorial; doable with space and dense planting, but watch for chasing.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Diamond Tetra⚠️ With cautionPeaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
- Black Skirt Tetra and Diamond Tetra are close in size, but the semi-aggressive one tends to dominate — add diamond tetra in a group to spread the pressure.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Diamond Tetra in a shoal of 6+ or it gets stressed and nippy.
- Dwarf Chain Loach⚠️ With cautionPeaceful · 6 cm · Medium care · 24–29 °C (75–84 °F)
- Your 75 L tank is below the ~80 L this pairing really wants — crowding raises aggression.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Dwarf Chain Loach in a shoal of 6+ or it gets stressed and nippy.
- Eastern Betta⚠️ With cautionSemi-aggressive · 6 cm · Medium care · 24–28 °C (75–82 °F)
- Black Skirt Tetra and Eastern Betta can both be territorial; doable with space and dense planting, but watch for chasing.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Glass Bloodfin Tetra⚠️ With cautionPeaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
- Black Skirt Tetra is semi-aggressive and may chase or nip the smaller Glass Bloodfin Tetra — plant heavily and break up sight lines.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Glass Bloodfin Tetra in a shoal of 6+ or it gets stressed and nippy.
- GloFish Tetra⚠️ With cautionSemi-aggressive · 6 cm · Easy care · 21–28 °C (70–82 °F)
- Black Skirt Tetra and GloFish Tetra can both be territorial; doable with space and dense planting, but watch for chasing.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep GloFish Tetra in a shoal of 6+ or it gets stressed and nippy.
- Guppy⚠️ With cautionPeaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
- Expect Black Skirt Tetra to harass Guppy at times; give dense cover and watch them at feeding.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Neon Dwarf Rainbowfish⚠️ With cautionPeaceful · 6 cm · Easy care · 23–27 °C (73–81 °F)
- Black Skirt Tetra and Neon Dwarf Rainbowfish are close in size, but the semi-aggressive one tends to dominate — add neon dwarf rainbowfish in a group to spread the pressure.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Neon Dwarf Rainbowfish in a shoal of 6+ or it gets stressed and nippy.
- Odessa Barb⚠️ With cautionSemi-aggressive · 6 cm · Easy care · 20–26 °C (68–79 °F)
- Black Skirt Tetra and Odessa Barb can both be territorial; doable with space and dense planting, but watch for chasing.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Odessa Barb in a shoal of 6+ or it gets stressed and nippy.
- Peaceful Betta⚠️ With cautionSemi-aggressive · 6 cm · Medium care · 24–28 °C (75–82 °F)
- Both are a bit pushy (semi-aggressive + semi-aggressive) — workable only in a larger tank with cover and broken sight lines.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Pearl Danio⚠️ With cautionPeaceful · 6 cm · Easy care · 20–25 °C (68–77 °F)
- Black Skirt Tetra and Pearl Danio are close in size, but the semi-aggressive one tends to dominate — add pearl danio in a group to spread the pressure.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Pearl Danio in a shoal of 6+ or it gets stressed and nippy.
- Platy⚠️ With cautionPeaceful · 6 cm · Easy care · 21–28 °C (70–82 °F)
- Black Skirt Tetra and Platy are close in size, but the semi-aggressive one tends to dominate — add platy in a group to spread the pressure.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Samurai Gourami⚠️ With cautionPeaceful · 6 cm · Hard care · 24–28 °C (75–82 °F)
- Black Skirt Tetra is semi-aggressive and may chase or nip the smaller Samurai Gourami — plant heavily and break up sight lines.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Three-striped Dwarf Cichlid⚠️ With cautionSemi-aggressive · 6 cm · Medium care · 23–29 °C (73–84 °F)
- Both are a bit pushy (semi-aggressive + semi-aggressive) — workable only in a larger tank with cover and broken sight lines.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Alligator Gar⛔ Not recommendedAggressive · 250 cm · Hard care · 24–28 °C (75–82 °F)
- Black Skirt Tetra and Alligator Gar are both territorial and at least one is outright aggressive — expect serious fighting.
- Alligator Gar (250 cm) is big enough to swallow the 6 cm Black Skirt Tetra whole.
- Black Skirt Tetra is a notorious fin-nipper — even though Alligator Gar is larger, an active shoal will harass its trailing fins. Only safe in a full group of 6+ with plenty of cover.
- Your 75 L tank is below the ~3785 L this pairing really wants — crowding raises aggression.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Clown Knifefish⛔ Not recommendedAggressive · 90 cm · Hard care · 24–28 °C (75–82 °F)
- Two assertive fish, one genuinely aggressive: Black Skirt Tetra and Clown Knifefish will hold territory and clash.
- Size gap is too large (90 vs 6 cm): Clown Knifefish will treat Black Skirt Tetra as food.
- Your 75 L tank is below the ~750 L this pairing really wants — crowding raises aggression.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Fire Eel⛔ Not recommendedSemi-aggressive · 100 cm · Medium care · 24–28 °C (75–82 °F)
- Fire Eel (100 cm) is big enough to swallow the 6 cm Black Skirt Tetra whole.
- Black Skirt Tetra and Fire Eel can both be territorial; doable with space and dense planting, but watch for chasing.
- Your 75 L tank is below the ~380 L this pairing really wants — crowding raises aggression.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Koi⛔ Not recommendedPeaceful · 90 cm · Medium care · 4–28 °C (39–82 °F)
- Koi (90 cm) is big enough to swallow the 6 cm Black Skirt Tetra whole.
- Koi is slow and long-finned; a busy black skirt tetra shoal tends to nip at it. Keep black skirt tetra in a proper group of 6+ and watch them closely.
- Your 75 L tank is below the ~3800 L this pairing really wants — crowding raises aggression.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Redtail Catfish⛔ Not recommendedAggressive · 120 cm · Hard care · 24–27 °C (75–81 °F)
- Black Skirt Tetra and Redtail Catfish are both territorial and at least one is outright aggressive — expect serious fighting.
- Black Skirt Tetra is bite-sized to a 120 cm predatory redtail catfish — it will be eaten.
- Your 75 L tank is below the ~5700 L this pairing really wants — crowding raises aggression.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Spotted Gar⛔ Not recommendedAggressive · 90 cm · Hard care · 18–26 °C (64–79 °F)
- Black Skirt Tetra and Spotted Gar are both territorial and at least one is outright aggressive — expect serious fighting.
- Black Skirt Tetra is bite-sized to a 90 cm predatory spotted gar — it will be eaten.
- Black Skirt Tetra is a notorious fin-nipper — even though Spotted Gar is larger, an active shoal will harass its trailing fins. Only safe in a full group of 6+ with plenty of cover.
- Your 75 L tank is below the ~600 L this pairing really wants — crowding raises aggression.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Wels Catfish⛔ Not recommendedAggressive · 300 cm · Hard care · 15–25 °C (59–77 °F)
- Black Skirt Tetra and Wels Catfish are both territorial and at least one is outright aggressive — expect serious fighting.
- Black Skirt Tetra is bite-sized to a 300 cm predatory wels catfish — it will be eaten.
- Your 75 L tank is below the ~20000 L this pairing really wants — crowding raises aggression.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
- Wolf Cichlid⛔ Not recommendedAggressive · 72 cm · Hard care · 24–30 °C (75–86 °F)
- Two assertive fish, one genuinely aggressive: Black Skirt Tetra and Wolf Cichlid will hold territory and clash.
- Size gap is too large (72 vs 6 cm): Wolf Cichlid will treat Black Skirt Tetra as food.
- Wolf Cichlid is slow and long-finned; a busy black skirt tetra shoal tends to nip at it. Keep black skirt tetra in a proper group of 6+ and watch them closely.
- Your 75 L tank is below the ~760 L this pairing really wants — crowding raises aggression.
- Keep Black Skirt Tetra in a shoal of 6+ or it gets stressed and nippy.
Compatibility is computed from each species' care data — a strong starting point, not a guarantee. Individual temperament varies, so always introduce new fish slowly and watch them.
Black Skirt Tetra care specs
- Care level
- Easy
- Breeding
- Medium
- Max size
- 6 cm (2.4 in)
- Min tank size
- 75 L (19.8 gal)
- Temperature
- 20–26 °C (68–79 °F)
- pH
- 6–7.5
- Hardness
- 5–15 dGH
- Lifespan
- 3–5 years
- Diet
- Omnivore
- Swim level
- Middle
- Group size
- 6+ (shoaling)
- Family
- Characidae
- Origin
- South America — Mato Grosso, Bolivia, and the Paraguay River basin
What is a Black Skirt Tetra?
The black skirt tetra (Gymnocorymbus ternetzi) is a striking, deep-bodied characin from the rivers of South America. Its common names — black widow tetra, petticoat tetra — all gesture at its most defining feature: a sweeping black anal fin that flares out beneath the body like a skirt or veil. The body itself grades from bright silver at the head to deep black toward the tail, a contrast that is boldest in juveniles and softens to charcoal grey as adults.
Growing to about 6 cm (2.4 in), these fish are compact, robust, and tolerant of a broader range of conditions than most tetras. Captive breeding has produced a popular long-finned variant and dyed “painted” versions — avoid the latter, as the dyeing process stresses and shortens the fish’s life.
Where do Black Skirt Tetras come from?
Black skirt tetras are native to South America, specifically the Mato Grosso region of Brazil, Bolivia, and the Paraguay River basin. Their natural habitat is slow-moving to moderately flowing rivers, streams, and tributaries with tannin-stained water, dense marginal vegetation, and a soft, dark substrate covered in leaf litter.
This origin explains their preference for soft, slightly acidic water and lower light levels. Wild shoals pick off small invertebrates, insects, and plant matter from the middle water column — a varied diet that maps directly onto their omnivore classification in captivity.
What size tank does a Black Skirt Tetra need?
A minimum of 75 litres (20 gallons) is the practical starting point, and that assumes a shoal of six — the minimum group needed to keep this species settled. Black skirt tetras are active, mid-water swimmers that use the full length of the tank, so a tank that prioritises horizontal footprint over height is preferable: a standard 90 cm (36 in) long tank serves a small group well.
Larger groups, or a community with other species, call for proportionally more space. A 100–120 L (26–32 gal) tank gives a shoal of six to ten fish comfortable room and makes stocking a mixed community straightforward. Keep the interior open in the centre for swimming, with denser planting along the sides and back, and add some floating plants or a dimmed light to replicate the shaded canopy of their native rivers.
What water parameters do Black Skirt Tetras need?
- Temperature: 20–26 °C (68–79 °F) — cooler than many tropical tetras, which makes them adaptable but incompatible with fish that need 28 °C+.
- pH: 6.0–7.5 — soft to neutral.
- Hardness: 5–15 dGH — soft to moderately hard.
The cooler temperature range is worth noting when choosing tank mates: species that need 27–28 °C are a poor pairing. Stability matters most — cycle the tank fully before adding fish, change around 25% of the water weekly, and keep filter flow gentle enough not to batter those trailing fins.
What do Black Skirt Tetras eat?
Black skirt tetras are omnivores with an unfussy appetite. In the wild they eat small invertebrates, insects, zooplankton, and plant material. In the aquarium, a quality flake or micro pellet forms a sensible daily staple. Supplement with small frozen or live foods — daphnia, bloodworm, brine shrimp, and micro-worm all work well — several times a week to keep colour vivid and condition good.
Feed small amounts once or twice a day — only what the fish can consume in two to three minutes — and remove any uneaten food promptly. Fish fed a mixed diet look noticeably better than those kept on flake alone.
Are Black Skirt Tetras aggressive — and what fish can live with them?
Black skirt tetras are rated semi-aggressive, and fin-nipping is their main antisocial behaviour. The risk is highest when the group is too small — a solitary fish or a pair becomes nippy because it lacks the inward social focus a proper shoal provides. Keep six or more and this behaviour drops substantially.
The fins of long-finned or slow-moving fish are the most common targets. Bettas, angelfish, guppies with fancy tails, and other long-finned or slow tank mates should generally be avoided. Good companions are similarly sized, short-finned, active fish that can hold their own: other medium tetras, danios, rasboras, and robust corydoras on the bottom are all reasonable choices. Species requiring significantly warmer water are a poor match due to the temperature gap.
For a full compatibility breakdown, see Black Skirt Tetra tank mates.
How do you tell male and female Black Skirt Tetras apart?
Sexing black skirt tetras is straightforward once the fish are mature. Females are noticeably broader and rounder in the belly, particularly when conditioned for breeding, and their body tends to be slightly wider overall. Males are slimmer and marginally smaller, and have a distinctive small white dot on the caudal fin — a useful identifier when the fish are at rest and the belly shape is less obvious.
The belly difference becomes clear at feeding time or when females are carrying eggs. Younger juveniles can be tricky, but by the time fish reach around 3–4 cm the differences are usually apparent.
How do Black Skirt Tetras breed?
Black skirt tetras are egg scatterers with a moderate level of breeding difficulty. Spawning occurs readily if the fish are in good condition, but raising fry successfully requires some preparation. A separate, bare-bottomed breeding tank of around 40–60 L works well, with dim lighting and a thin layer of fine-leaved plants or spawning mops to catch the adhesive eggs. Use soft, slightly acidic water at the cooler end of the range.
Condition the fish with live and frozen foods for a week or two before moving them to the breeding tank. Spawning typically happens in the morning; both sexes scatter eggs freely and provide no parental care — remove the adults immediately after spawning or they will eat the eggs. Eggs hatch in 24–36 hours, and fry are free-swimming within another two to three days. Begin feeding infusoria or commercial fry food, moving to baby brine shrimp as they grow.
What are common Black Skirt Tetra diseases?
Black skirt tetras are hardy and resistant compared to more sensitive tetras, but the usual freshwater diseases still apply. Ich (white spot disease) presents as a dusting of fine white spots and is almost always triggered by a sudden temperature drop or stress from transport. Fin rot causes ragged, fraying fin edges and is predominantly a water-quality problem. Velvet (a gold-dust sheen) and neon tetra disease — which affects multiple characin species — can occur in tanks with poor biosecurity.
Prevention is consistent: stable, clean water; two-to-four-week quarantine for all new arrivals; no sharp temperature swings; and a varied diet. Colour loss or clamped fins are early warning signs worth investigating promptly.
Health note: disease identification and medication decisions are outside the scope of a care profile. For any sick fish, confirm the diagnosis against a reputable veterinary or fish-health source before reaching for any treatment.
How long do Black Skirt Tetras live?
With good care, black skirt tetras live 3–5 years. They are on the robust end for tetras of their size, and a stable, well-maintained community tank — consistent water quality, a varied diet, and a properly sized shoal — will see them through that full range comfortably.
Colour fading in the first year or two is normal and should not be mistaken for a health problem: the vivid black of juveniles naturally mutes to a dark charcoal grey in adults. Stress, poor water quality, and bright overhead lighting accelerate this fade; a darker substrate and some floating cover slow it. A fish that reaches full adult colour and holds it consistently is a fish in good condition.
Frequently asked questions
Do black skirt tetras fin-nip?
They can, especially in groups smaller than six. Keeping them in a proper shoal of six or more redirects their attention inward and significantly cuts fin-nipping. Avoid pairing them with long-finned or slow-moving tank mates like angelfish or betta — the trailing fins are too tempting.
Why do black skirt tetras lose their black colour?
The intense black fades naturally as they age, usually turning to a charcoal grey in adults past one year. Stress, poor water quality, or too-bright lighting can speed the fade. Good water conditions and a darker substrate with floating plants help preserve colour.
What you need to keep a black skirt tetra
The baseline is a heated, filtered 75 L+ tank: a reliable heater to hold 20–26 °C (68–79 °F), a gentle filter that won't batter a black skirt tetra in the current, and a tight-fitting lid. Cycle the tank fully before adding any fish.
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