Had one for 6 years in a previous 90g tank. I had mine with 1 male to 14 female and never any very serious aggression, now maybe because of the large amount of females I didnt have a problem.
Single Auratus can be kept in tanks but they need to be on the bigger side ie 75g or above, this fish is more than capable of killing an entire tank and swimming happily alone by itself if it wants to turn on the aggression.
Generally to keep a single one (male or female are equally as aggressive), you would need an aquarium with a ton of rocks and lots of line of sight breaks, the less the fish can see other fish the better. A single fish will be happy with its own area provided the other fish in the tank have their own area and areas to escape if it does turn on the aggression. No other fish that look even remotely similar as it go after them usually with deadly consequences. There is nothing really you can do to stop it other than remove the fish if it wants to be aggressive. I had a 10" adult Venustus once in a 125g tank with a single Auratus female and it had no problem going after it.
keep it with the more aggressive fish that can stand up to it, ie Demansoni and it can work but as this fish is naturally aggressive you still need to be very careful with it. Only sure fire to make it work is to keep it with a lot 8-10or more female. Never attempt to keep multiple males or females unless you have at least a 125g or bigger tank, they will simply kill each other and the rest of the tank with them.
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