The African Butterflyfish has substantial pectoral fins that resemble Those people of a butterfly, that's why the fish’s frequent name. Once airborne, the fish fans out the fins To maximise the surface location and basically fly! The Black Ghost Knife fish provides extra unusual condition and movement in your tank! https://aquariumcleaningservice.blogspot.com/2022/10/how-to-set-up-aquarium.html