I am responding to your continued inaccuracy because you keep calling me out. Your latest post suggests your knowledge of fish physiology is very limited, or you would realize that there is more to numbers than safety in the wild. This expectation that they will be in a group of their own species is programmed into their DNA. You can ignore it and risk the fish's health, or you can recognize and provide accordingly in order to have healthier fish.
As for the authorities I named, they will all tell you that you need a group of these fish in order for the fish to be settled and healthy. Not having this means the fish is under stress and this weakens the fish's immune system and beyond.
And I did not say six was mandatory, I said five is the minimum recommended by the authorities [there was a study done a few years back but I'd probably never find it now] but more will always result in healthier happier fish, however you want to define "happier." And this is not my opinion, it is scientific fact.