Can pictus catfish live with black ghost knives?

Verdict
No

No. Pictus catfish and black ghost knives should not share a tank. An adult black ghost knife eats fish that fit in its mouth, and at 5 inches pictus catfish do.

What to watch

What works

Water side by side

55°60°65°70°75°80°85°90°Both: 73–79°Pictus catfish 72–79°Black ghost knife 73–82°
The green band is the temperature range both can live in.
456789Both: 6–7.5Pictus catfish 6–7.5Black ghost knife 6–8
The green band is the pH both tolerate.

Size to scale

Pictus catfish · 5 inBlack ghost knife · 15 in0"2"4"6"8"10"12"14"
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

Pictus catfishBlack ghost knife
Temperature72–79 °F73–82 °F
pH6–7.56–8
Adult size5.0 in15.0 in
Minimum tank55 gal125 gal
TemperamentSemi-aggressiveSemi-aggressive
Swims atBottomBottom
GroupGroups of 3+One per tank
DietCarnivoreCarnivore

Better tank mates for pictus catfish

All pictus catfish tank mates

Better tank mates for black ghost knives

All black ghost knife tank mates

Questions

Can pictus catfish live with black ghost knives?

No. Pictus catfish and black ghost knives should not share a tank. An adult black ghost knife eats fish that fit in its mouth, and at 5 inches pictus catfish do.

What temperature suits both pictus catfish and black ghost knives?

73–79 °F. Pictus catfish need 72–79 °F, black ghost knives need 73–82 °F.

What size tank do pictus catfish and black ghost knives need together?

At least 125 gal, set by the black ghost knife. Add space for each extra fish.