Tank mates for least killifish

We checked least killifish against all 149 other species in our database for water temperature, pH, size, fin nipping, predation and aggression.

Good tank mates for least killifish include cherry shrimp, nerite snail, guppy, dwarf gourami, neon tetra and panda corydoras. Avoid angelfish, common goldfish and fancy goldfish: angelfish can eat least killifish: they're small enough to fit in its mouth once it's grown.

Least killifish: 20–26°C (68–79°F), pH 7–8, adult size 2.5 cm (1 in), minimum tank 10 gallons (38 L). Full least killifish care guide.

Check a full stocking plan

Good Compatible tank mates (89)

Shared water conditions and no known conflict. Still add fish slowly and watch them.

Caution Possible, with care (24)

These can work in the right setup, but there is a real risk. Read the reason first.

  • Betta fish · 5+ gal
    • Betta fish is semi-aggressive and may bully much smaller least killifish.
  • Tiger barb · 29+ gal
    • Tiger barb nips fins and can stress slow, peaceful fish like least killifish.
    • Tiger barb is semi-aggressive and may bully much smaller least killifish.
  • Boesemani rainbowfish · 29+ gal
    • Their temperature ranges barely overlap (only around 26–26°C).
  • Clown loach · 180+ gal
    • Their temperature ranges barely overlap (only around 25–26°C).
    • Clown loach grows much larger than least killifish and may swallow them as it grows.
  • Dojo loach · 75+ gal
    • Dojo loach grows much larger than least killifish and may swallow them as it grows.
  • Kribensis · 29+ gal
    • Kribensis is semi-aggressive and may bully much smaller least killifish.
  • Rainbow shark · 75+ gal
    • Rainbow shark is semi-aggressive and may bully much smaller least killifish.
    • Rainbow shark grows much larger than least killifish and may swallow them as it grows.
  • Red-tail shark · 75+ gal
    • Red-tail shark is semi-aggressive and may bully much smaller least killifish.
  • Siamese algae eater · 55+ gal
    • Siamese algae eater grows much larger than least killifish and may swallow them as it grows.
  • Three spot gourami · 29+ gal
    • Three spot gourami is semi-aggressive and may bully much smaller least killifish.
  • White cloud mountain minnow · 15+ gal
    • One is a cold-water species and the other is tropical, so neither will be at its best.
  • Agassiz's dwarf cichlid · 20+ gal
    • Their temperature ranges barely overlap (only around 25–26°C).
    • Agassiz's dwarf cichlid is semi-aggressive and may bully much smaller least killifish.
  • Buenos Aires tetra · 29+ gal
    • Buenos Aires tetra nips fins and can stress slow, peaceful fish like least killifish.
    • Buenos Aires tetra is semi-aggressive and may bully much smaller least killifish.
  • Cockatoo cichlid · 20+ gal
    • Cockatoo cichlid is semi-aggressive and may bully much smaller least killifish.
  • Crystal red shrimp · 10+ gal
    • Their preferred pH ranges don't quite overlap (7–8 vs 6–6.8).
  • Gardneri killifish · 10+ gal
    • Gardneri killifish is semi-aggressive and may bully much smaller least killifish.
  • Kissing gourami · 75+ gal
    • Kissing gourami is semi-aggressive and may bully much smaller least killifish.
    • Kissing gourami grows much larger than least killifish and may swallow them as it grows.
  • Rabbit snail · 29+ gal
    • Their temperature ranges barely overlap (only around 25–26°C).
  • Scissortail rasbora · 55+ gal
    • Scissortail rasbora may eat least killifish, especially young or small ones.
  • Serpae tetra · 20+ gal
    • Serpae tetra nips fins and can stress slow, peaceful fish like least killifish.
  • Zebra pleco · 20+ gal
    • Their temperature ranges barely overlap (only around 26–26°C).
  • Dwarf rasbora · 10+ gal
    • Their preferred pH ranges don't quite overlap (7–8 vs 5–6.5).
  • Green neon tetra · 10+ gal
    • Their preferred pH ranges don't quite overlap (7–8 vs 5–6.5).
  • Keyhole cichlid · 29+ gal
    • Keyhole cichlid may eat least killifish, especially young or small ones.

Avoid Bad tank mates (36)

  • Angelfish: Angelfish can eat least killifish: they're small enough to fit in its mouth once it's grown.
  • Common goldfish: Common goldfish can eat least killifish: they're small enough to fit in its mouth once it's grown.
  • Fancy goldfish: Fancy goldfish can eat least killifish: they're small enough to fit in its mouth once it's grown.
  • Oscar: Oscar can eat least killifish: they're small enough to fit in its mouth once it's grown.
  • Bala shark: Bala shark can eat least killifish: they're small enough to fit in its mouth once it's grown.
  • Blood parrot cichlid: Blood parrot cichlid can eat least killifish: they're small enough to fit in its mouth once it's grown.
  • Chinese algae eater: Chinese algae eater is aggressive and will bully or injure peaceful least killifish.
  • Convict cichlid: Convict cichlid can eat least killifish: they're small enough to fit in its mouth once it's grown. Convict cichlid is aggressive and will bully or injure peaceful least killifish.
  • Discus: They need different temperatures: Least killifish 20–26°C (68–79°F), discus 28–30°C (82–86°F).
  • Electric blue acara: Electric blue acara can eat least killifish: they're small enough to fit in its mouth once it's grown.
  • Electric yellow cichlid: Electric yellow cichlid is a Lake Malawi cichlid. It needs a Lake Malawi tank: hard, alkaline water (pH 7.5–8.5), plenty of rockwork and other cichlids from the same lake. Least killifish don't belong in that setup.
  • Firemouth cichlid: Firemouth cichlid can eat least killifish: they're small enough to fit in its mouth once it's grown.
  • German blue ram: They need different temperatures: Least killifish 20–26°C (68–79°F), german blue ram 27–30°C (81–86°F).
  • Jack Dempsey: Jack Dempsey can eat least killifish: they're small enough to fit in its mouth once it's grown. Jack Dempsey is aggressive and will bully or injure peaceful least killifish.
  • Pea puffer: Pea puffer is aggressive and will bully or injure peaceful least killifish. Pea puffer is best kept in a species-only tank.
  • Peacock cichlid: Peacock cichlid can eat least killifish: they're small enough to fit in its mouth once it's grown. Peacock cichlid is a Lake Malawi cichlid. It needs a Lake Malawi tank: hard, alkaline water (pH 7.5–8.5), plenty of rockwork and other cichlids from the same lake. Least killifish don't belong in that setup.
  • Pictus catfish: Pictus catfish can eat least killifish: they're small enough to fit in its mouth once it's grown.
  • Red zebra cichlid: Red zebra cichlid is aggressive and will bully or injure peaceful least killifish. Red zebra cichlid is a Lake Malawi cichlid. It needs a Lake Malawi tank: hard, alkaline water (pH 7.5–8.5), plenty of rockwork and other cichlids from the same lake. Least killifish don't belong in that setup.
  • Senegal bichir: Senegal bichir can eat least killifish: they're small enough to fit in its mouth once it's grown.
  • Silver dollar: Silver dollar can eat least killifish: they're small enough to fit in its mouth once it's grown.
  • African butterfly fish: African butterfly fish can eat least killifish: they're small enough to fit in its mouth once it's grown.
  • Black ghost knifefish: Black ghost knifefish can eat least killifish: they're small enough to fit in its mouth once it's grown.
  • Bumblebee catfish: Bumblebee catfish can eat least killifish: they're small enough to fit in its mouth once it's grown.
  • Demasoni cichlid: Demasoni cichlid is aggressive and will bully or injure peaceful least killifish. Demasoni cichlid is a Lake Malawi cichlid. It needs a Lake Malawi tank: hard, alkaline water (pH 7.5–8.5), plenty of rockwork and other cichlids from the same lake. Least killifish don't belong in that setup.
  • Frontosa: Frontosa can eat least killifish: they're small enough to fit in its mouth once it's grown. Frontosa is a Lake Tanganyika cichlid. It needs a Lake Tanganyika tank: hard, alkaline water (pH 8–9), plenty of rockwork and other cichlids from the same lake. Least killifish don't belong in that setup.
  • Giant danio: Giant danio can eat least killifish: they're small enough to fit in its mouth once it's grown.
  • Golden wonder killifish: Golden wonder killifish can eat least killifish: they're small enough to fit in its mouth once it's grown.
  • Green terror: Green terror can eat least killifish: they're small enough to fit in its mouth once it's grown. Green terror is aggressive and will bully or injure peaceful least killifish.
  • Jewel cichlid: Jewel cichlid can eat least killifish: they're small enough to fit in its mouth once it's grown. Jewel cichlid is aggressive and will bully or injure peaceful least killifish.
  • Paradise fish: Paradise fish can eat least killifish: they're small enough to fit in its mouth once it's grown.
  • Ropefish: Ropefish can eat least killifish: they're small enough to fit in its mouth once it's grown.
  • Severum: Severum can eat least killifish: they're small enough to fit in its mouth once it's grown.
  • Shell dweller cichlid: Shell dweller cichlid is a Lake Tanganyika cichlid. It needs a Lake Tanganyika tank: hard, alkaline water (pH 7.5–9), plenty of rockwork and other cichlids from the same lake. Least killifish don't belong in that setup.
  • Tinfoil barb: Tinfoil barb can eat least killifish: they're small enough to fit in its mouth once it's grown.
  • Upside-down catfish: Upside-down catfish can eat least killifish: they're small enough to fit in its mouth once it's grown.
  • Moonlight gourami: Moonlight gourami can eat least killifish: they're small enough to fit in its mouth once it's grown.

Frequently asked questions

What fish can live with least killifish?

Good tank mates for least killifish include cherry shrimp, nerite snail, guppy, dwarf gourami, neon tetra and panda corydoras. They need similar water and won't fight with or eat least killifish.

Can least killifish live with angelfish?

No. Angelfish can eat least killifish: they're small enough to fit in its mouth once it's grown. Angelfish is semi-aggressive and may bully much smaller least killifish.

Can least killifish live with bettas?

Sometimes, with care. Betta fish is semi-aggressive and may bully much smaller least killifish.

Can least killifish live with bristlenose plecos?

Yes. They share similar water needs (22–26°C (72–79°F)) and peaceful temperaments.

Can least killifish live with bronze corydoras?

Yes. They share similar water needs (21–26°C (70–79°F)) and peaceful temperaments.

How we decide: we compare each pair's comfortable temperature, pH and hardness ranges, adult sizes, mouth size (who can eat whom), fin nipping, aggression and territory. Read the full method. Data last reviewed 2026-10-13.