Can killifish live with severums?

Verdict
Yes

Yes, killifish and severums can live together. Both are fine at 74–77°F. Plan on at least 55 gal.

KillifishKillifish70–77°F · pH 5.5–7 SeverumSeverum74–84°F · pH 6–7

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 74–77°Killifish 70–77°Severum 74–84°
The green band is the temperature range both can live in.
456789Both: 6–7Killifish 5.5–7Severum 6–7
The green band is the pH both tolerate.

Size to scale

Killifish · 2.5 inSeverum · 8 in0"1"2"3"4"5"6"7"8"
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

KillifishSeverum
Temperature70–77 °F74–84 °F
pH5.5–76–7
Adult size2.5 in8.0 in
Minimum tank10 gal55 gal
TemperamentPeacefulSemi-aggressive
Swims atTopMiddle
GroupAlone or in pairsAlone or in pairs
DietCarnivoreOmnivore

Better tank mates for killifish

All killifish tank mates

Better tank mates for severums

All severum tank mates

Questions

Can killifish live with severums?

Yes, killifish and severums can live together. Both are fine at 74–77°F. Plan on at least 55 gal.

What temperature suits both killifish and severums?

74–77 °F. Killifish need 70–77 °F, severums need 74–84 °F.

What size tank do killifish and severums need together?

At least 55 gal, set by the severum. Add space for each extra fish.