Can upside down catfish live with endlers?

Verdict
Yes

Yes, upside down catfish and endlers can live together. Both are fine at 72–79°F. Plan on at least 30 gal.

Upside down catfishUpside down catfish72–79°F · pH 6–7.5 Endler's livebearerEndler's livebearer72–82°F · pH 7–8

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 72–79°Upside down catfish 72–79°Endler's livebearer 72–82°
The green band is the temperature range both can live in.
456789Both: 7–7.5Upside down catfish 6–7.5Endler's livebearer 7–8
The green band is the pH both tolerate.

Size to scale

Upside down catfish · 4 inEndler's livebearer · 1 in0"1"2"3"4"5"6"
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

Upside down catfishEndler's livebearer
Temperature72–79 °F72–82 °F
pH6–7.57–8
Adult size4.0 in1.0 in
Minimum tank30 gal5 gal
TemperamentPeacefulPeaceful
Swims atBottomTop
GroupGroups of 3+Groups of 3+
DietOmnivoreOmnivore

Better tank mates for upside down catfish

All upside down catfish tank mates

Better tank mates for endlers

All endler's livebearer tank mates

Questions

Can upside down catfish live with endlers?

Yes, upside down catfish and endlers can live together. Both are fine at 72–79°F. Plan on at least 30 gal.

What temperature suits both upside down catfish and endlers?

72–79 °F. Upside down catfish need 72–79 °F, endlers need 72–82 °F.

What size tank do upside down catfish and endlers need together?

At least 30 gal, set by the upside down catfish. Add space for each extra fish.