I recently purchased two Banggai Cardinals with the hope of getting a pair. After reading a lot I chose two larger fish one with a longer second dorsal fin. They have been in quarantine for a week and I have noticed that one( with the longer fin) stays in the corner most of the time. It comes out to feed and some after lights out. Is this an indication I have two males? Will they be OK together in my 120 gal display tank if they are males?