Golden Wonder Killifish Tank Mates

Golden Wonder Killifish is semi-aggressive, so its tank mates need choosing with care. Here are the 33 freshwater species that pair well with a golden wonder killifish — plus the 130 to avoid — with a live checker you can tune to your own tank.

By The Aquarium DB Team • Updated June 7, 2026 • Full Golden Wonder Killifish care guide →
Best matches

The best tank mates for a golden wonder killifish

  • Axelrod's Cory ✅ Compatible
    Easy care · Peaceful · 5 cm · 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.
  • Bandit Corydoras ✅ Compatible
    Easy care · Peaceful · 5 cm · 22–27 °C (72–81 °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.
  • Japanese Trapdoor Snail ✅ Compatible
    Easy care · Peaceful · 5 cm · 10–28 °C (50–82 °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.
  • Julii Corydoras ✅ Compatible
    Easy care · Peaceful · 5 cm · 23–26 °C (73–79 °F)
    Compatible on the things that matter: shared water near 23–26 °C, workable temperaments, and no predator-and-prey size gap.
  • Masked Corydoras ✅ Compatible
    Easy care · Peaceful · 5 cm · 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.
  • Skunk Corydoras ✅ Compatible
    Easy care · Peaceful · 5 cm · 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.
  • Rust Corydoras ✅ Compatible
    Easy care · Peaceful · 5.5 cm · 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.
  • Agassiz's Corydoras ✅ Compatible
    Easy care · Peaceful · 6 cm · 22–28 °C (72–82 °F)
    Compatible on the things that matter: shared water near 22–28 °C, workable temperaments, and no predator-and-prey size gap.
  • Elegant Cory ✅ Compatible
    Easy care · Peaceful · 6 cm · 22–28 °C (72–82 °F)
    Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 22–28 °C — no size, zone or temperament conflicts.
  • False Julii Corydoras ✅ Compatible
    Easy care · Peaceful · 6 cm · 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.
  • Corydoras Catfish ✅ Compatible
    Easy care · Peaceful · 6.5 cm · 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.
  • Spotfin Corydoras ✅ Compatible
    Easy care · Peaceful · 6.5 cm · 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.
  • Peppered Corydoras ✅ Compatible
    Easy care · Peaceful · 7 cm · 18–26 °C (64–79 °F)
    Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 22–26 °C — no size, zone or temperament conflicts.
  • Spotted Corydoras ✅ Compatible
    Easy care · Peaceful · 7 cm · 22–27 °C (72–81 °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.
  • Black Kuhli Loach ✅ Compatible
    Easy care · Peaceful · 8 cm · 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.
  • Burmese Loach ✅ Compatible
    Easy care · Peaceful · 9 cm · 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.
  • Kuhli Loach ✅ Compatible
    Easy care · Peaceful · 10 cm · 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.
  • Murray River Rainbowfish ✅ Compatible
    Easy care · Peaceful · 11 cm · 15–26 °C (59–79 °F)
    Compatible on the things that matter: shared water near 22–26 °C, workable temperaments, and no predator-and-prey size gap.
  • Giant Kuhli Loach ✅ Compatible
    Easy care · Peaceful · 12 cm · 24–30 °C (75–86 °F)
    Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–28 °C — no size, zone or temperament conflicts.
  • Blue Turbo Snail ✅ Compatible
    Medium care · Peaceful · 5 cm · 25–30 °C (77–86 °F)
    Compatible on the things that matter: shared water near 25–28 °C, workable temperaments, and no predator-and-prey size gap.
  • Horseman Cory ✅ Compatible
    Medium care · Peaceful · 5 cm · 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.
  • Panda Corydoras ✅ Compatible
    Medium care · Peaceful · 5 cm · 20–26 °C (68–79 °F)
    Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 22–26 °C — no size, zone or temperament conflicts.
  • Adolf's Cory ✅ Compatible
    Medium care · Peaceful · 5.5 cm · 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.
  • Duplicareus Corydoras ✅ Compatible
    Medium care · Peaceful · 5.5 cm · 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.
With caution

Golden Wonder Killifish tank mates that can work with care

  • Afra Cichlid ⚠️ With caution
    Medium care · Semi-aggressive · 10 cm · 24–28 °C (75–82 °F)
    Different pH ranges (6–7.5 vs 7.8–8.6); doable if you sit in the shared band, but not ideal long-term.
  • African Butterfly Cichlid ⚠️ With caution
    Medium care · Semi-aggressive · 8 cm · 22–28 °C (72–82 °F)
    Both are a bit pushy (semi-aggressive + semi-aggressive) — workable only in a larger tank with cover and broken sight lines.
  • Agassiz's Dwarf Cichlid ⚠️ With caution
    Medium care · Semi-aggressive · 9 cm · 24–30 °C (75–86 °F)
    Golden Wonder Killifish and Agassiz's Dwarf Cichlid can both be territorial; doable with space and dense planting, but watch for chasing.
  • Altifrons Geophagus ⚠️ With caution
    Medium care · Semi-aggressive · 25 cm · 24–28 °C (75–82 °F)
    Golden Wonder Killifish and Altifrons Geophagus can both be territorial; doable with space and dense planting, but watch for chasing.
  • Amano Shrimp ⚠️ With caution
    Easy care · Peaceful · 5 cm · 18–28 °C (64–82 °F)
    Golden Wonder Killifish may eat Amano Shrimp or pick off its shrimplets — a densely planted tank with moss gives them a fighting chance.
  • Amazon Puffer ⚠️ With caution
    Medium care · Peaceful · 8 cm · 23–28 °C (73–82 °F)
    Golden Wonder Killifish and Amazon Puffer are close in size, but the semi-aggressive one tends to dominate — add amazon puffer in a group to spread the pressure.
  • Angelfish ⚠️ With caution
    Medium care · Semi-aggressive · 15 cm · 24–30 °C (75–86 °F)
    Both are a bit pushy (semi-aggressive + semi-aggressive) — workable only in a larger tank with cover and broken sight lines.
  • Angelicus Synodontis ⚠️ With caution
    Medium care · Semi-aggressive · 25 cm · 23–27 °C (73–81 °F)
    Golden Wonder Killifish and Angelicus Synodontis can both be territorial; doable with space and dense planting, but watch for chasing.

+ 169 more “with caution” pairings — see the interactive checker above.

Avoid

Fish to avoid keeping with a golden wonder killifish

  • Wels Catfish ⛔ Avoid
    Hard care · Aggressive · 300 cm · 15–25 °C (59–77 °F)
    Two assertive fish, one genuinely aggressive: Golden Wonder Killifish and Wels Catfish will hold territory and clash.
  • Alligator Gar ⛔ Avoid
    Hard care · Aggressive · 250 cm · 24–28 °C (75–82 °F)
    Two assertive fish, one genuinely aggressive: Golden Wonder Killifish and Alligator Gar will hold territory and clash.
  • Redtail Catfish ⛔ Avoid
    Hard care · Aggressive · 120 cm · 24–27 °C (75–81 °F)
    Two assertive fish, one genuinely aggressive: Golden Wonder Killifish and Redtail Catfish will hold territory and clash.
  • Fire Eel ⛔ Avoid
    Medium care · Semi-aggressive · 100 cm · 24–28 °C (75–82 °F)
    Fire Eel (100 cm) is big enough to swallow the 10 cm Golden Wonder Killifish whole.
  • Clown Knifefish ⛔ Avoid
    Hard care · Aggressive · 90 cm · 24–28 °C (75–82 °F)
    Golden Wonder Killifish and Clown Knifefish are both territorial and at least one is outright aggressive — expect serious fighting.
  • Koi ⛔ Avoid
    Medium care · Peaceful · 90 cm · 4–28 °C (39–82 °F)
    Size gap is too large (90 vs 10 cm): Koi will treat Golden Wonder Killifish as food.
  • Spotted Gar ⛔ Avoid
    Hard care · Aggressive · 90 cm · 18–26 °C (64–79 °F)
    Two assertive fish, one genuinely aggressive: Golden Wonder Killifish and Spotted Gar will hold territory and clash.
  • Wolf Cichlid ⛔ Avoid
    Hard care · Aggressive · 72 cm · 24–30 °C (75–86 °F)
    Golden Wonder Killifish and Wolf Cichlid are both territorial and at least one is outright aggressive — expect serious fighting.

+ 122 more to avoid — the checker above flags every one.

Interactive tool

Check any fish against a golden wonder killifish

Dial in your exact tank size and filter by result — the checker scores every species in our database against a golden wonder killifish, with the reasoning for each verdict.

Tank-mate checker

Will it live with a Golden Wonder Killifish?

We compare each fish against your golden wonder killifish on temperament, size, water parameters and swimming zone. Set your tank size and filter the results.

  • Adolf's Cory✅ Compatible
    Peaceful · 5.5 cm · Medium 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 Adolf's Cory in a shoal of 6+ or it gets stressed and nippy.
  • Agassiz's Corydoras✅ Compatible
    Peaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
    • Compatible on the things that matter: shared water near 22–28 °C, workable temperaments, and no predator-and-prey size gap.
    • Keep Agassiz's Corydoras in a shoal of 6+ or it gets stressed and nippy.
  • Banjo Catfish✅ Compatible
    Peaceful · 15 cm · Medium care · 20–26 °C (68–79 °F)
    • Compatible on the things that matter: shared water near 22–26 °C, workable temperaments, and no predator-and-prey size gap.
  • Black Kuhli Loach✅ Compatible
    Peaceful · 8 cm · Easy 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.
  • Blood Red Tiger Pleco✅ Compatible
    Peaceful · 6 cm · Medium care · 24–29 °C (75–84 °F)
    • Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–28 °C — no size, zone or temperament conflicts.
  • Bolivian Ram✅ Compatible
    Peaceful · 8 cm · Medium care · 24–28 °C (75–82 °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.
  • Burmese Loach✅ Compatible
    Peaceful · 9 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.
  • Corydoras Catfish✅ Compatible
    Peaceful · 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 Corydoras Catfish in a shoal of 6+ or it gets stressed and nippy.
  • Duplicareus Corydoras✅ Compatible
    Peaceful · 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 Duplicareus Corydoras in a shoal of 6+ or it gets stressed and nippy.
  • Elegant Cory✅ Compatible
    Peaceful · 6 cm · Easy care · 22–28 °C (72–82 °F)
    • Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 22–28 °C — no size, zone or temperament conflicts.
    • Keep Elegant Cory in a shoal of 6+ or it gets stressed and nippy.
  • False Julii Corydoras✅ Compatible
    Peaceful · 6 cm · Easy 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 False Julii Corydoras in a shoal of 6+ or it gets stressed and nippy.
  • Giant Betta✅ Compatible
    Peaceful · 12 cm · Medium care · 24–28 °C (75–82 °F)
    • Compatible on the things that matter: shared water near 24–28 °C, workable temperaments, and no predator-and-prey size gap.
  • Giant Kuhli Loach✅ Compatible
    Peaceful · 12 cm · Easy care · 24–30 °C (75–86 °F)
    • Semi-aggressive + Peaceful, but with no direct clash here, and their water overlaps around 24–28 °C — no size, zone or temperament conflicts.
  • Kuhli Loach✅ Compatible
    Peaceful · 10 cm · Easy 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.
  • Leopard Frog Pleco✅ Compatible
    Peaceful · 9 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.
  • Murray River Rainbowfish✅ Compatible
    Peaceful · 11 cm · Easy care · 15–26 °C (59–79 °F)
    • Compatible on the things that matter: shared water near 22–26 °C, workable temperaments, and no predator-and-prey size gap.
    • Keep Murray River Rainbowfish in a shoal of 6+ or it gets stressed and nippy.
  • Narcissus II Cory✅ Compatible
    Peaceful · 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 Narcissus II Cory in a shoal of 6+ or it gets stressed and nippy.
  • Peppered Corydoras✅ Compatible
    Peaceful · 7 cm · Easy care · 18–26 °C (64–79 °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 Peppered Corydoras in a shoal of 6+ or it gets stressed and nippy.
  • Rust Corydoras✅ Compatible
    Peaceful · 5.5 cm · Easy 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 Rust Corydoras in a shoal of 6+ or it gets stressed and nippy.
  • Slate Corydoras✅ Compatible
    Peaceful · 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 Slate Corydoras in a shoal of 6+ or it gets stressed and nippy.
  • Spotfin Corydoras✅ Compatible
    Peaceful · 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 Spotfin Corydoras in a shoal of 6+ or it gets stressed and nippy.
  • Spotted Corydoras✅ Compatible
    Peaceful · 7 cm · Easy care · 22–27 °C (72–81 °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 Spotted Corydoras in a shoal of 6+ or it gets stressed and nippy.
  • Spotted Rubbernose Pleco✅ Compatible
    Peaceful · 12 cm · Medium care · 20–26 °C (68–79 °F)
    • Compatible on the things that matter: shared water near 22–26 °C, workable temperaments, and no predator-and-prey size gap.
  • Sterbai Corydoras✅ Compatible
    Peaceful · 6.5 cm · Medium care · 24–30 °C (75–86 °F)
    • Compatible on the things that matter: shared water near 24–28 °C, workable temperaments, and no predator-and-prey size gap.
    • Keep Sterbai Corydoras in a shoal of 6+ or it gets stressed and nippy.
  • Afra Cichlid⚠️ With caution
    Semi-aggressive · 10 cm · Medium care · 24–28 °C (75–82 °F)
    • Different pH ranges (6–7.5 vs 7.8–8.6); doable if you sit in the shared band, but not ideal long-term.
    • 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 ~150 L this pairing really wants — crowding raises aggression.
    • Keep Afra Cichlid in a shoal of 6+ or it gets stressed and nippy.
  • Bearded Corydoras⚠️ With caution
    Peaceful · 10 cm · Medium care · 18–24 °C (64–75 °F)
    • Your 75 L tank is below the ~80 L this pairing really wants — crowding raises aggression.
    • Keep Bearded Corydoras in a shoal of 6+ or it gets stressed and nippy.
  • Clown Rasbora⚠️ With caution
    Peaceful · 10 cm · Medium care · 23–28 °C (73–82 °F)
    • Golden Wonder Killifish is semi-aggressive and may chase or nip the smaller Clown Rasbora — plant heavily and break up sight lines.
    • Your 75 L tank is below the ~110 L this pairing really wants — crowding raises aggression.
    • Keep Clown Rasbora in a shoal of 6+ or it gets stressed and nippy.
  • Daffodil Cichlid⚠️ With caution
    Semi-aggressive · 10 cm · Medium care · 23–27 °C (73–81 °F)
    • pH preferences only just meet (Golden Wonder Killifish 6–7.5 vs Daffodil Cichlid 7.8–9) — target the overlap and acclimate slowly.
    • Golden Wonder Killifish and Daffodil Cichlid can both be territorial; doable with space and dense planting, but watch for chasing.
    • Your 75 L tank is below the ~120 L this pairing really wants — crowding raises aggression.
  • Electric Yellow Cichlid⚠️ With caution
    Semi-aggressive · 10 cm · Medium care · 23–26 °C (73–79 °F)
    • Different pH ranges (6–7.5 vs 7.8–8.9); doable if you sit in the shared band, but not ideal long-term.
    • 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 ~200 L this pairing really wants — crowding raises aggression.
  • Giant Danio⚠️ With caution
    Peaceful · 10 cm · Easy care · 20–27 °C (68–81 °F)
    • Golden Wonder Killifish and Giant Danio are close in size, but the semi-aggressive one tends to dominate — add giant danio in a group to spread the pressure.
    • Your 75 L tank is below the ~110 L this pairing really wants — crowding raises aggression.
    • Keep Giant Danio in a shoal of 6+ or it gets stressed and nippy.
  • Keyhole Cichlid⚠️ With caution
    Peaceful · 10 cm · Easy care · 22–28 °C (72–82 °F)
    • Golden Wonder Killifish and Keyhole Cichlid are close in size, but the semi-aggressive one tends to dominate — add keyhole cichlid in a group to spread the pressure.
    • Your 75 L tank is below the ~80 L this pairing really wants — crowding raises aggression.
  • Kribensis⚠️ With caution
    Semi-aggressive · 10 cm · Easy care · 24–27 °C (75–81 °F)
    • Golden Wonder Killifish and Kribensis can both be territorial; doable with space and dense planting, but watch for chasing.
  • Molly⚠️ With caution
    Peaceful · 10 cm · Easy care · 23–28 °C (73–82 °F)
    • Expect Golden Wonder Killifish to harass Molly at times; give dense cover and watch them at feeding.
  • Porthole Catfish⚠️ With caution
    Peaceful · 10 cm · Easy care · 22–28 °C (72–82 °F)
    • Your 75 L tank is below the ~80 L this pairing really wants — crowding raises aggression.
  • Rosy Barb⚠️ With caution
    Semi-aggressive · 10 cm · Easy care · 18–26 °C (64–79 °F)
    • Both are a bit pushy (semi-aggressive + semi-aggressive) — workable only in a larger tank with cover and broken sight lines.
    • Keep Rosy Barb in a shoal of 6+ or it gets stressed and nippy.
  • Rusty Cichlid⚠️ With caution
    Semi-aggressive · 10 cm · Medium care · 24–28 °C (75–82 °F)
    • pH preferences only just meet (Golden Wonder Killifish 6–7.5 vs Rusty Cichlid 7.8–8.5) — target the overlap and acclimate slowly.
    • Golden Wonder Killifish and Rusty Cichlid can both be territorial; doable with space and dense planting, but watch for chasing.
    • Your 75 L tank is below the ~150 L this pairing really wants — crowding raises aggression.
  • Tanganyikan Butterfly Cichlid⚠️ With caution
    Semi-aggressive · 10 cm · Hard care · 24–28 °C (75–82 °F)
    • pH preferences only just meet (Golden Wonder Killifish 6–7.5 vs Tanganyikan Butterfly Cichlid 8–9) — target the overlap and acclimate slowly.
    • Golden Wonder Killifish and Tanganyikan Butterfly Cichlid can both be territorial; doable with space and dense planting, but watch for chasing.
    • Your 75 L tank is below the ~130 L this pairing really wants — crowding raises aggression.
  • Topaz Cichlid⚠️ With caution
    Semi-aggressive · 10 cm · Medium care · 23–28 °C (73–82 °F)
    • Both are a bit pushy (semi-aggressive + semi-aggressive) — workable only in a larger tank with cover and broken sight lines.
  • Upside-down Catfish⚠️ With caution
    Peaceful · 10 cm · Easy care · 22–26 °C (72–79 °F)
    • Your 75 L tank is below the ~115 L this pairing really wants — crowding raises aggression.
  • Zebra Pleco⚠️ With caution
    Peaceful · 10 cm · Hard care · 26–30 °C (79–86 °F)
    • Your 75 L tank is below the ~80 L this pairing really wants — crowding raises aggression.
  • Alligator Gar⛔ Not recommended
    Aggressive · 250 cm · Hard care · 24–28 °C (75–82 °F)
    • Two assertive fish, one genuinely aggressive: Golden Wonder Killifish and Alligator Gar will hold territory and clash.
    • Size gap is too large (250 vs 10 cm): Alligator Gar will treat Golden Wonder Killifish as food.
    • Your 75 L tank is below the ~3785 L this pairing really wants — crowding raises aggression.
  • Clown Knifefish⛔ Not recommended
    Aggressive · 90 cm · Hard care · 24–28 °C (75–82 °F)
    • Golden Wonder Killifish and Clown Knifefish are both territorial and at least one is outright aggressive — expect serious fighting.
    • Golden Wonder Killifish 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.
  • Fire Eel⛔ Not recommended
    Semi-aggressive · 100 cm · Medium care · 24–28 °C (75–82 °F)
    • Fire Eel (100 cm) is big enough to swallow the 10 cm Golden Wonder Killifish whole.
    • 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.
  • Koi⛔ Not recommended
    Peaceful · 90 cm · Medium care · 4–28 °C (39–82 °F)
    • Size gap is too large (90 vs 10 cm): Koi will treat Golden Wonder Killifish as food.
    • Your 75 L tank is below the ~3800 L this pairing really wants — crowding raises aggression.
  • Redtail Catfish⛔ Not recommended
    Aggressive · 120 cm · Hard care · 24–27 °C (75–81 °F)
    • Two assertive fish, one genuinely aggressive: Golden Wonder Killifish and Redtail Catfish will hold territory and clash.
    • Golden Wonder Killifish 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.
  • Spotted Gar⛔ Not recommended
    Aggressive · 90 cm · Hard care · 18–26 °C (64–79 °F)
    • Two assertive fish, one genuinely aggressive: Golden Wonder Killifish and Spotted Gar will hold territory and clash.
    • Golden Wonder Killifish is bite-sized to a 90 cm predatory spotted gar — it will be eaten.
    • Your 75 L tank is below the ~600 L this pairing really wants — crowding raises aggression.
  • Wels Catfish⛔ Not recommended
    Aggressive · 300 cm · Hard care · 15–25 °C (59–77 °F)
    • Two assertive fish, one genuinely aggressive: Golden Wonder Killifish and Wels Catfish will hold territory and clash.
    • Golden Wonder Killifish 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.
  • Wolf Cichlid⛔ Not recommended
    Aggressive · 72 cm · Hard care · 24–30 °C (75–86 °F)
    • Golden Wonder Killifish and Wolf Cichlid are both territorial and at least one is outright aggressive — expect serious fighting.
    • Wolf Cichlid (72 cm) is big enough to swallow the 10 cm Golden Wonder Killifish whole.
    • Your 75 L tank is below the ~760 L this pairing really wants — crowding raises aggression.

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.

Setting up a golden wonder killifish community tank

Give the group a stable, planted 75 L+ tank with a gentle filter, a reliable heater and plenty of cover — broken sight lines and hiding spots let mid-water and bottom dwellers keep out of each other's way. Cycle it fully and stock gradually.

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How to choose

How to choose the right tank mates for a golden wonder killifish

Being semi-aggressive, golden wonder killifish can nip or harass smaller, slower or long-finned fish — give it space, broken sight-lines and similarly robust companions. It mostly occupies the top of the tank, so it pairs naturally with species that use the other levels.

Golden Wonder Killifish grows to about 10 cm, so avoid tank mates small enough to be seen as food — as a rule of thumb, skip anything under roughly 5 cm. Match its water, too: aim for 22–28 °C (72–82 °F), pH 6–7.5 and 5–15 dGH. Fish needing very different conditions — coldwater species, or hard-water lovers against a soft-water fish — rarely thrive side by side.

Golden Wonder Killifish doesn't need its own kind to feel secure; think twice before keeping more than one if it is territorial. Whatever you add, introduce new fish slowly, watch for bullying in the first days, and have a backup plan if temperaments clash.

FAQ

Frequently asked questions

Can a golden wonder killifish live with other fish?

Yes — with the right companions. Our checker finds 33 compatible freshwater species for golden wonder killifish. Pick calm, similarly-sized fish that share its water needs and add them to a mature, well-planted tank.

What is the best tank mate for a golden wonder killifish?

Easy, peaceful, similarly-sized species top the list — for example Axelrod's Cory, Bandit Corydoras, Japanese Trapdoor Snail. Use the checker above to match against your own tank size.

What fish should you avoid keeping with a golden wonder killifish?

Avoid Wels Catfish, Alligator Gar, Redtail Catfish and similar — usually a temperature, size or temperament clash. The full "avoid" list below gives the reason for each.

How big a tank do golden wonder killifish tank mates need?

Start from Golden Wonder Killifish's own minimum and scale up with every addition. The checker above defaults to a 75 L community tank and flags pairings that need more room — drag the slider to match your setup.

← Back to the full Golden Wonder Killifish care guide