Here is a picture of my pbass that share my predator tank with an aro, rays, a dat and some silver dollars. They always seem to get the market shrimp before anyone else in the tank and they are growing the fastest (except for maybe the rays).
I don't know a lot about pbass, how can you tell if they are a pair? They seem to chase each other a bit and flare their gills when the lights first go out but they are always peaceful and together when the lights are on, even when they are being fed. They are about 10" long so they should be old enough to pair off (how can you tell male from female?). Do the males always have a bump on their head?