in my opinon, only lucius and pleuro can mix with some preditory fishes like gars, polys, africa aro... there are 3 pleuro, 1 florida gar, 1 delhezi, 1 endli, 2 silver aro, 3 indo dat in my tank, and they live with each other in peace. i've followed them about 3 month and i'm sure about it.