Rope Fish is a specialist 'oddball' predator (such as bichirs, arowana, gar, knifefish or eels). Most grow large and hunt, so the exact species dictates tank size and tankmates.
Care tips
Use a tight, weighted lid — most oddball predators jump or climb.
Predatory: never house with fish small enough to be swallowed.
Research the exact species — many outgrow standard aquariums dramatically.