Can severums live with hatchetfish?

Verdict

Yes, with care

Yes, with care. Severums and hatchetfish can share a tank, but watch one thing. At 8 inches a severum can swallow a small hatchetfish. Fast, alert fish usually stay out of reach.

Severum74–84°F · pH 6–7

Hatchetfish75–81°F · pH 5.5–7.5

What to watch

Watch outAt 8 inches a severum can swallow a small hatchetfish. Fast, alert fish usually stay out of reach.

What works

Both are fine at 75–81°F.
pH 6–7 suits both.
They use different parts of the tank: severums the mid, hatchetfish 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

	Severum	Hatchetfish
Temperature	74–84 °F	75–81 °F
pH	6–7	5.5–7.5
Adult size	8.0 in	1.5 in
Minimum tank	55 gal	20 gal
Temperament	Semi-aggressive	Peaceful
Swims at	Middle	Top
Group	Alone or in pairs	Groups of 6+
Diet	Omnivore	Carnivore

Better tank mates for severums

All severum tank mates

Better tank mates for hatchetfish

All hatchetfish tank mates

Questions

Can severums live with hatchetfish?

Yes, with care. Severums and hatchetfish can share a tank, but watch one thing. At 8 inches a severum can swallow a small hatchetfish. Fast, alert fish usually stay out of reach.

What temperature suits both severums and hatchetfish?

75–81 °F. Severums need 74–84 °F, hatchetfish need 75–81 °F.

What size tank do severums and hatchetfish need together?

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