TankmateChecker

Can bichirs live with killifish?

Verdict

No

No. Bichirs and killifish should not share a tank. An adult bichir eats fish that fit in its mouth, and at 2.5 inches killifish do.

Bichir

Bichir72–82°F · pH 6.5–7.5

Killifish

Killifish70–77°F · pH 5.5–7

What to watch

Deal breakerAn adult bichir eats fish that fit in its mouth, and at 2.5 inches killifish do.
Watch outBichirs grow to 12 inches and need 75 gallons, far more than a tank set up for killifish.

What works

Both are fine at 72–77°F.
pH 6.5–7 suits both.
They use different parts of the tank: bichirs the bottom, killifish the top.

Water side by side

The green band is the temperature range both can live in.

The green band is the pH both tolerate.

Size to scale

Adult length in an aquarium. A fish can swallow anything that fits in its mouth, roughly a third to half its own length for predators.

Care at a glance

	Bichir	Killifish
Temperature	72–82 °F	70–77 °F
pH	6.5–7.5	5.5–7
Adult size	12.0 in	2.5 in
Minimum tank	75 gal	10 gal
Temperament	Semi-aggressive	Peaceful
Swims at	Bottom	Top
Group	Alone or in pairs	Alone or in pairs
Diet	Carnivore	Carnivore

Better tank mates for bichirs

All bichir tank mates

Better tank mates for killifish

All killifish tank mates

Questions

Can bichirs live with killifish?

No. Bichirs and killifish should not share a tank. An adult bichir eats fish that fit in its mouth, and at 2.5 inches killifish do.

What temperature suits both bichirs and killifish?

72–77 °F. Bichirs need 72–82 °F, killifish need 70–77 °F.

What size tank do bichirs and killifish need together?

At least 75 gal, set by the bichir. Add space for each extra fish.