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Serpae Tetra (Hyphessobrycon eques)
A jewel-red schooling fish with a temper: stunning in a well-planted 60 L+ tank, but it will shred the fins of any slow or long-finned neighbour if you skip the group.
Will it live with a Serpae Tetra?
We compare each fish against your serpae tetra on temperament, size, water parameters and swimming zone. Set your tank size and filter the results.
- African Dwarf Frog✅ CompatiblePeaceful · 4 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 Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Amano Shrimp✅ CompatiblePeaceful · 5 cm · Easy care · 18–28 °C (64–82 °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 Serpae Tetra 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 23–28 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Serpae 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)
- Compatible on the things that matter: shared water near 23–27 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Serpae 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.
- Black Phantom Tetra✅ CompatiblePeaceful · 4.5 cm · Easy care · 22–28 °C (72–82 °F)
- Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 23–28 °C — no size, zone or temperament conflicts.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Keep Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Black Phantom 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, and their water overlaps around 25–28 °C — no size, zone or temperament conflicts.
- Keep Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Checkered Barb✅ CompatiblePeaceful · 5 cm · Easy care · 20–25 °C (68–77 °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 Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Checkered Barb in a shoal of 6+ or it gets stressed and nippy.
- Cherry Barb✅ CompatiblePeaceful · 5 cm · Easy care · 23–27 °C (73–81 °F)
- Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 23–27 °C — no size, zone or temperament conflicts.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Keep Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Cherry Barb in a shoal of 6+ or it gets stressed and nippy.
- Chocolate Gourami✅ CompatiblePeaceful · 5 cm · Hard 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.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Keep Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Chocolate Gourami in a shoal of 6+ or it gets stressed and nippy.
- Cochu's Blue Tetra✅ CompatiblePeaceful · 5 cm · Medium care · 22–28 °C (72–82 °F)
- Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 23–28 °C — no size, zone or temperament conflicts.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Keep Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Cochu's Blue Tetra in a shoal of 8+ or it gets stressed and nippy.
- Firehead Tetra✅ CompatiblePeaceful · 5 cm · Medium care · 24–28 °C (75–82 °F)
- Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–28 °C — no size, zone or temperament conflicts.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Keep Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Firehead Tetra in a shoal of 8+ or it gets stressed and nippy.
- Five-banded Barb✅ CompatiblePeaceful · 5 cm · Easy care · 23–27 °C (73–81 °F)
- Compatible on the things that matter: shared water near 23–27 °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 Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Five-banded Barb in a shoal of 6+ or it gets stressed and nippy.
- Forktail Blue-eye✅ CompatiblePeaceful · 5 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 Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Forktail Blue-eye in a shoal of 6+ or it gets stressed and nippy.
- Gold Tetra✅ CompatiblePeaceful · 4.5 cm · Easy care · 23–28 °C (73–82 °F)
- Compatible on the things that matter: shared water near 23–28 °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 Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Gold Tetra in a shoal of 6+ or it gets stressed and nippy.
- Half-striped Penguin Tetra✅ CompatiblePeaceful · 5 cm · Medium care · 23–28 °C (73–82 °F)
- Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 23–28 °C — no size, zone or temperament conflicts.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Keep Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Half-striped Penguin Tetra in a shoal of 6+ or it gets stressed and nippy.
- Harlequin Rasbora✅ CompatiblePeaceful · 5 cm · Easy care · 23–28 °C (73–82 °F)
- Compatible on the things that matter: shared water near 23–28 °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 Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Harlequin Rasbora 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; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Keep Serpae 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.
- Japanese Trapdoor Snail✅ CompatiblePeaceful · 5 cm · Easy care · 10–28 °C (50–82 °F)
- Compatible on the things that matter: shared water near 23–28 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Lemon Tetra✅ CompatiblePeaceful · 4.5 cm · Easy care · 23–28 °C (73–82 °F)
- Compatible on the things that matter: shared water near 23–28 °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 Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Lemon Tetra in a shoal of 6+ or it gets stressed and nippy.
- Otocinclus✅ CompatiblePeaceful · 4 cm · Medium care · 21–26 °C (70–79 °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 Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Otocinclus in a shoal of 6+ or it gets stressed and nippy.
- Tailspotted Oto✅ CompatiblePeaceful · 3.5 cm · Medium care · 22–27 °C (72–81 °F)
- Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 23–27 °C — no size, zone or temperament conflicts.
- Keep Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Tailspotted Oto in a shoal of 6+ or it gets stressed and nippy.
- Tiger Otocinclus✅ CompatiblePeaceful · 4 cm · Medium care · 22–27 °C (72–81 °F)
- Compatible on the things that matter: shared water near 23–27 °C, workable temperaments, and no predator-and-prey size gap.
- Keep Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Tiger Otocinclus in a shoal of 6+ or it gets stressed and nippy.
- X-ray Tetra✅ CompatiblePeaceful · 4.5 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.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Keep Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep X-ray Tetra in a shoal of 6+ or it gets stressed and nippy.
- Yellow Tetra✅ CompatiblePeaceful · 4.5 cm · Easy care · 20–25 °C (68–77 °F)
- Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 23–25 °C — no size, zone or temperament conflicts.
- Both favour the middle of the tank — offer enough cover so they aren't always in each other's space.
- Keep Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Yellow Tetra in a shoal of 6+ or it gets stressed and nippy.
- Amapá Tetra⚠️ With cautionPeaceful · 4 cm · Medium care · 24–27 °C (75–81 °F)
- Serpae Tetra and Amapá Tetra are close in size, but the semi-aggressive one tends to dominate — add amapá tetra in a group to spread the pressure.
- Keep Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Amapá Tetra in a shoal of 6+ or it gets stressed and nippy.
- Black Darter Tetra⚠️ With cautionSemi-aggressive · 4 cm · Hard care · 21–28 °C (70–82 °F)
- Both are a bit pushy (semi-aggressive + semi-aggressive) — workable only in a larger tank with cover and broken sight lines.
- Keep Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Blue Danio⚠️ With cautionPeaceful · 4 cm · Easy care · 21–26 °C (70–79 °F)
- Serpae Tetra and Blue Danio are close in size, but the semi-aggressive one tends to dominate — add blue danio in a group to spread the pressure.
- Keep Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Blue Danio in a shoal of 6+ or it gets stressed and nippy.
- Blue Emperor Tetra⚠️ With cautionPeaceful · 4 cm · Medium care · 23–27 °C (73–81 °F)
- Expect Serpae Tetra to harass Blue Emperor Tetra at times; give dense cover and watch them at feeding.
- Keep Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Blue Emperor Tetra in a shoal of 6+ or it gets stressed and nippy.
- Cardinal Tetra⚠️ With cautionPeaceful · 4 cm · Medium care · 23–27 °C (73–81 °F)
- Serpae Tetra is semi-aggressive and may chase or nip the smaller Cardinal Tetra — plant heavily and break up sight lines.
- Keep Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Cardinal Tetra in a shoal of 6+ or it gets stressed and nippy.
- Emperor Tetra⚠️ With cautionPeaceful · 4 cm · Easy care · 23–27 °C (73–81 °F)
- Serpae Tetra and Emperor Tetra are close in size, but the semi-aggressive one tends to dominate — add emperor tetra in a group to spread the pressure.
- Keep Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Emperor Tetra in a shoal of 6+ or it gets stressed and nippy.
- Flame Tetra⚠️ With cautionPeaceful · 4 cm · Easy care · 22–28 °C (72–82 °F)
- Serpae Tetra and Flame Tetra are close in size, but the semi-aggressive one tends to dominate — add flame tetra in a group to spread the pressure.
- Keep Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Flame Tetra in a shoal of 6+ or it gets stressed and nippy.
- Ghost Shrimp⚠️ With cautionPeaceful · 4 cm · Easy care · 18–28 °C (64–82 °F)
- Adult Ghost Shrimp might survive with Serpae Tetra, but expect the young to be eaten — plant heavily.
- Keep Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Ghost Shrimp in a shoal of 6+ or it gets stressed and nippy.
- Glowlight Tetra⚠️ With cautionPeaceful · 4 cm · Easy care · 22–28 °C (72–82 °F)
- Serpae Tetra and Glowlight Tetra are close in size, but the semi-aggressive one tends to dominate — add glowlight tetra in a group to spread the pressure.
- Keep Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Glowlight Tetra in a shoal of 6+ or it gets stressed and nippy.
- Golden Dwarf Barb⚠️ With cautionPeaceful · 4 cm · Easy care · 18–24 °C (64–75 °F)
- Serpae Tetra and Golden Dwarf Barb are close in size, but the semi-aggressive one tends to dominate — add golden dwarf barb in a group to spread the pressure.
- Keep Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Golden Dwarf Barb in a shoal of 6+ or it gets stressed and nippy.
- Jelly Bean Tetra⚠️ With cautionPeaceful · 4 cm · Medium care · 20–26 °C (68–79 °F)
- Expect Serpae Tetra to harass Jelly Bean Tetra at times; give dense cover and watch them at feeding.
- Keep Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Jelly Bean Tetra in a shoal of 10+ or it gets stressed and nippy.
- Marbled Hatchetfish⚠️ With cautionPeaceful · 4 cm · Medium care · 23–28 °C (73–82 °F)
- Serpae Tetra and Marbled Hatchetfish are close in size, but the semi-aggressive one tends to dominate — add marbled hatchetfish in a group to spread the pressure.
- Keep Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Marbled Hatchetfish in a shoal of 6+ or it gets stressed and nippy.
- Phoenix Tetra⚠️ With cautionPeaceful · 4 cm · Easy care · 23–28 °C (73–82 °F)
- Expect Serpae Tetra to harass Phoenix Tetra at times; give dense cover and watch them at feeding.
- Keep Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Phoenix Tetra in a shoal of 8+ or it gets stressed and nippy.
- Purple Tetra⚠️ With cautionPeaceful · 4 cm · Medium care · 22–26 °C (72–79 °F)
- Expect Serpae Tetra to harass Purple Tetra at times; give dense cover and watch them at feeding.
- Keep Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Purple Tetra in a shoal of 8+ or it gets stressed and nippy.
- Red Phantom Tetra⚠️ With cautionPeaceful · 4 cm · Easy care · 22–28 °C (72–82 °F)
- Expect Serpae Tetra to harass Red Phantom Tetra at times; give dense cover and watch them at feeding.
- Keep Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Red Phantom Tetra in a shoal of 8+ or it gets stressed and nippy.
- Rosy Tetra⚠️ With cautionPeaceful · 4 cm · Easy care · 22–28 °C (72–82 °F)
- Expect Serpae Tetra to harass Rosy Tetra at times; give dense cover and watch them at feeding.
- Keep Serpae Tetra in a shoal of 6+ or it gets stressed and nippy.
- Keep Rosy 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)
- Two assertive fish, one genuinely aggressive: Serpae Tetra and Alligator Gar will hold territory and clash.
- Serpae Tetra is bite-sized to a 250 cm predatory alligator gar — it will be eaten.
- Alligator Gar is slow and long-finned; a busy serpae tetra shoal tends to nip at it. Keep serpae tetra in a proper group of 6+ and watch them closely.
- Your 75 L tank is below the ~3785 L this pairing really wants — crowding raises aggression.
- Keep Serpae 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)
- Serpae Tetra and Clown Knifefish are both territorial and at least one is outright aggressive — expect serious fighting.
- Serpae Tetra is bite-sized to a 90 cm predatory clown knifefish — it will be eaten.
- Your 75 L tank is below the ~750 L this pairing really wants — crowding raises aggression.
- Keep Serpae 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)
- Serpae Tetra is bite-sized to a 100 cm predatory fire eel — it will be eaten.
- 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 ~380 L this pairing really wants — crowding raises aggression.
- Keep Serpae 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)
- Serpae Tetra is bite-sized to a 90 cm koi — it will be eaten.
- Serpae Tetra is a notorious fin-nipper — even though Koi 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 ~3800 L this pairing really wants — crowding raises aggression.
- Keep Serpae 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)
- Two assertive fish, one genuinely aggressive: Serpae Tetra and Redtail Catfish will hold territory and clash.
- Redtail Catfish (120 cm) is big enough to swallow the 4 cm Serpae Tetra whole.
- Your 75 L tank is below the ~5700 L this pairing really wants — crowding raises aggression.
- Keep Serpae 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)
- Two assertive fish, one genuinely aggressive: Serpae Tetra and Spotted Gar will hold territory and clash.
- Size gap is too large (90 vs 4 cm): Spotted Gar will treat Serpae Tetra as food.
- Spotted Gar is slow and long-finned; a busy serpae tetra shoal tends to nip at it. Keep serpae tetra in a proper group of 6+ and watch them closely.
- Your 75 L tank is below the ~600 L this pairing really wants — crowding raises aggression.
- Keep Serpae 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)
- Two assertive fish, one genuinely aggressive: Serpae Tetra and Wels Catfish will hold territory and clash.
- Serpae 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 Serpae 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)
- Serpae Tetra and Wolf Cichlid are both territorial and at least one is outright aggressive — expect serious fighting.
- Serpae Tetra is bite-sized to a 72 cm predatory wolf cichlid — it will be eaten.
- Serpae Tetra is a notorious fin-nipper — even though Wolf Cichlid 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 ~760 L this pairing really wants — crowding raises aggression.
- Keep Serpae 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.
Serpae Tetra care specs
- Care level
- Easy
- Breeding
- Medium
- Max size
- 4 cm (1.6 in)
- Min tank size
- 60 L (15.9 gal)
- Temperature
- 23–28 °C (73–82 °F)
- pH
- 5.5–7.5
- Hardness
- 4–15 dGH
- Lifespan
- 3–7 years
- Diet
- Omnivore
- Swim level
- Middle
- Group size
- 6+ (shoaling)
- Family
- Characidae
- Origin
- South America — Paraguay and Guaporé River basins (Brazil, Bolivia, Paraguay)
What is a Serpae Tetra?
The serpae tetra (Hyphessobrycon eques) is a compact, jewel-red characin from South America and one of the most striking schooling fish available to the freshwater hobby. Reaching just 4 cm (1.6 in), it punches well above its size in terms of visual impact: a deep crimson body contrasted by a bold black dorsal fin tipped in white and a distinctive black humeral spot just behind the gill plate. Its common aliases — jewel tetra and callistus tetra — give a fair idea of how it looks under a good planted-tank light.
What the name does not advertise is the temperament. Serpae tetras are semi-aggressive fin nippers with a strong schooling instinct. Keep them correctly — a tight group of six or more in a well-planted, appropriately sized tank — and that energy stays mostly within the school. Cut corners on group size or add long-finned tank mates and the fins will suffer. This is not a fish to impulse-buy in a pair for a community tank; it is a fish to plan around.
Where do Serpae Tetras come from?
Serpae tetras are native to the Paraguay and Guaporé River basins of central South America, ranging across parts of Brazil, Bolivia and Paraguay. In the wild they occupy slow-moving rivers, streams and forest pools — warm, typically soft and slightly acidic water rich in tannins from leaf litter and decaying vegetation. The water is often tea-coloured, dimly lit through overhead canopy and dense with aquatic plants and submerged roots.
Understanding this origin helps explain the conditions they thrive in: warmth, gentle flow, some acidity or at least neutral pH, and plenty of visual structure in the tank. The commercial trade has made them broadly adaptable, but replicating the look of their blackwater home — dark substrate, driftwood, live plants — brings out their deepest colour.
What size tank does a Serpae Tetra need?
The minimum is 60 litres (16 gallons), and that figure is non-negotiable once you account for the group size they require. Six serpae tetras in anything smaller will be cramped, water quality will swing fast, and compressed space amplifies aggression toward tank mates.
A 75–90 L (20–24 gal) tank is a much more comfortable starting point for a school of six to eight. Prioritise floor length over height: serpae tetras are active mid-water swimmers and need a clear horizontal swimming corridor. Plant the sides and back densely — Java fern, Vallisneria, Cryptocoryne — and leave the centre open. Floating plants to diffuse light are a useful touch. A tight-fitting lid matters too; like most active tetras, they can jump when startled.
What water parameters do Serpae Tetras need?
Serpae tetras are genuinely adaptable, which is part of why they are rated Easy for care level:
- Temperature: 23–28 °C (73–82 °F). They tolerate the lower end well but are most active and colourful in the mid-to-upper range.
- pH: 5.5–7.5. They prefer soft, slightly acidic conditions in nature but do fine at neutral in most tap water.
- Hardness: 4–15 dGH. Low to moderate hardness suits them; very hard, alkaline water should be avoided long-term.
Stability is more important than hitting exact numbers. A cycled tank, weekly water changes of 25–30 %, and a reliable heater will cover the basics. If your tap water is particularly hard or alkaline, a small amount of driftwood or pre-boiled botanicals (catappa leaves) will gently lower pH and add tannins that make serpae tetras feel at home and look their best.
What do Serpae Tetras eat?
Serpae tetras are omnivores with an appetite for small invertebrates and organic matter. In the aquarium they accept a wide range of foods readily, which makes feeding straightforward:
- Staple: A quality small-grain flake or micro-pellet sized for a 4 cm (1.6 in) fish. Look for formulas with a protein-rich first ingredient.
- Enrichment: Frozen or live bloodworm, daphnia, brine shrimp and micro worms, offered two to three times per week. These trigger natural foraging behaviour and improve colour saturation noticeably.
- Vegetable matter: Small amounts of blanched spinach or spirulina-based flake round out the omnivore diet.
Feed small portions once or twice daily — only what the fish consume within two minutes. Uneaten food in a planted, active tetra tank degrades water quality quickly.
Are Serpae Tetras aggressive — and what fish can live with them?
Semi-aggressive is the accurate label, but the nuance matters: most of their aggression is directed at fins, not at chasing or injuring fish bodily. They are serial fin nippers, particularly when the school is too small, when the tank is overcrowded, or when a slow-moving, long-finned fish presents an irresistible target.
The solution is straightforward: keep eight or more to keep aggression directed inward within the school, and choose tank mates carefully. Good companions are fast-moving, short-finned fish of similar or larger size — tiger barbs (similarly feisty and a natural fit), black skirt tetras, corydoras catfish, bristlenose plecos, and robust mid-water tetras like black phantoms or rosy tetras. Avoid bettas, angelfish, fancy guppies, pearl gouramis, and any other slow or long-finned species.
For a full breakdown of tested pairings, check the Serpae Tetra tank mates page.
How do you tell male and female Serpae Tetras apart?
Sexual dimorphism in serpae tetras is subtle but consistent in a healthy, well-fed group. Females are noticeably plumper in the belly — especially when carrying eggs — and the overall body is a touch broader when viewed from above. Their colouration is slightly less saturated than males. Males are slimmer and more streamlined, with a more intensely black dorsal fin; in peak condition the white tip of the dorsal is crisper and the red of the body deeper. The difference becomes clearest when a female is ripening with eggs, making her abdomen visibly rounded compared to the male’s sleek profile.
How do Serpae Tetras breed?
Serpae tetras are egg scatterers and breed at medium difficulty — achievable for a keeper comfortable with a separate breeding setup. The key steps:
- Condition a pair or small group (one male, two females) on live or frozen foods for one to two weeks.
- Set up a breeding tank of 20–30 L (5–8 gal) with very soft, acidic water — pH 6.5–6.8, hardness under 5 dGH, temperature around 27 °C (81 °F). Dim lighting helps.
- Add fine-leaved plants (Java moss, hornwort) or synthetic spawning mops to catch adhesive eggs. A mesh or marbles over the base helps protect eggs from the parents.
- Introduce the conditioned fish in the evening. Spawning typically occurs in the morning with the first light.
- Remove adults immediately after spawning — serpae tetras are eager egg eaters and will consume the entire clutch if left in.
Eggs hatch in 24–36 hours. Fry become free-swimming in roughly five to seven days and can be started on infusoria or commercial liquid fry food, moving to baby brine shrimp as they grow.
What are common Serpae Tetra diseases?
Serpae tetras are hardy, but a few conditions are worth knowing:
- Ich (white spot disease): Fine white spots on fins and body, accompanied by flashing against surfaces. Caused by temperature drops or stress; common after transport or a cool spell. Gentle heat-raising (to 28–29 °C) can aid recovery alongside standard treatment. Prevention: stable temperature, avoid chilling when doing water changes.
- Fin rot: Ragged, darkening fin edges — almost always a water-quality problem. Keep ammonia and nitrite at zero and nitrate low. Prevention: consistent water changes and avoiding overcrowding.
- Neon tetra disease / Microsporidian infection: Pale, irregular patches along the body that do not respond to standard treatments. Incurable; affected fish should be removed and euthanised humanely to protect tank mates. Prevention: quarantine all new fish for two to four weeks before adding to the display tank.
- Velvet: A fine, dusty gold sheen on the body, often missed until advanced. Prevention: stable conditions and quarantine.
Health note: disease identification and treatment dosing are beyond the scope of a care profile. Before medicating, confirm symptoms against a reputable veterinary or aquatic-health source — misdiagnosis wastes time and can stress fish further.
How long do Serpae Tetras live?
With good care, serpae tetras live 3–7 years. The wide range reflects how much husbandry matters: fish kept in properly sized groups, stable water conditions and a varied diet consistently reach the upper end of that range, while those kept in marginal conditions rarely make it past three or four years. Because they are sold young, a well-maintained school bought today has the full lifespan ahead of it — give them the group size, tank space and water quality they need and they will reward you with years of colour.
Frequently asked questions
Are serpae tetras fin nippers — and can I keep them with bettas or angelfish?
Yes, serpae tetras are notorious fin nippers, especially when kept in groups of fewer than six. A larger school (eight or more) redirects aggression inward, reducing — but not eliminating — the risk to tank mates. Bettas, angelfish, fancy guppies and other long-finned or slow fish are poor choices; pair them instead with fast-moving, similarly sized tetras, corydoras, or robust rasboras.
How hard is it to breed serpae tetras?
Moderately straightforward for an intermediate keeper. Condition a pair or small group on live/frozen foods, then move them to a separate, dimly lit breeding tank with fine-leaved plants or spawning mops, soft acidic water (pH 6.5–6.8, under 5 dGH) and slightly warmer temperature (~27 °C). They scatter adhesive eggs; remove adults immediately after spawning or they will eat them. Fry are free-swimming within a week.
What you need to keep a serpae tetra
The baseline is a heated, filtered 60 L+ tank: a reliable heater to hold 23–28 °C (73–82 °F), a gentle filter that won't batter a serpae tetra in the current, and a tight-fitting lid. Cycle the tank fully before adding any fish.
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