Can crayfish live with dwarf neon rainbowfish?

Verdict
Yes

Yes. Crayfish and dwarf neon rainbowfish get along in the same tank. Both are fine at 75–77°F. Plan on at least 20 gal.

CrayfishCrayfish65–77°F · pH 6.5–8 Dwarf neon rainbowfishDwarf neon rainbowfish75–82°F · pH 6.5–7.5

Why it works

Water side by side

55°60°65°70°75°80°85°90°Both: 75–77°Crayfish 65–77°Dwarf neon rainbowfish 75–82°
The green band is the temperature range both can live in.
456789Both: 6.5–7.5Crayfish 6.5–8Dwarf neon rainbowfish 6.5–7.5
The green band is the pH both tolerate.

Size to scale

Crayfish · 5 inDwarf neon rainbowfish · 2.5 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

CrayfishDwarf neon rainbowfish
Temperature65–77 °F75–82 °F
pH6.5–86.5–7.5
Adult size5.0 in2.5 in
Minimum tank20 gal20 gal
TemperamentAggressivePeaceful
Swims atBottomMiddle
GroupOne per tankGroups of 6+
DietOmnivoreOmnivore

Better tank mates for crayfish

All crayfish tank mates

Better tank mates for dwarf neon rainbowfish

All dwarf neon rainbowfish tank mates

Questions

Can crayfish live with dwarf neon rainbowfish?

Yes. Crayfish and dwarf neon rainbowfish get along in the same tank. Both are fine at 75–77°F. Plan on at least 20 gal.

What temperature suits both crayfish and dwarf neon rainbowfish?

75–77 °F. Crayfish need 65–77 °F, dwarf neon rainbowfish need 75–82 °F.

What size tank do crayfish and dwarf neon rainbowfish need together?

At least 20 gal, set by the crayfish. Add space for each extra fish.