Be careful, while stressed or in QT/store systems they may seem to get along, but once a territory is established they don't like each other. I have never seen pairs in the wild except while breeding (one fish, my guess the female, is very fat and probably full of eggs) and I have collected both aculeatus and aya in pairs but after a short time they become very aggressive towards each other. I have lost fish to stress because of this so watch them once they are in the display tank where they will set up territories.
