Some fish do show aggressive behaviours. However, this is just a characteristic of that particular fish and not an indicative of a whole specie of moor. I have a fantail moor and he is the most placid fish I've had in a long time. Also, I've seen other aquariums where moors lived happily among orandas and ranchus. So I'd have to say no if you get another moor, it will most likely not behave like the one you have currently. But no guarantees...

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