I've found that African river cichlids like kribensis, as opposed to lake cichlids, mix well with similarly sized South and Central American cichlids.
My experience with firemouths is that they can sort of be dicks. They'll claim whatever they can in terms of territory and hierarchy any way they can.
When I had my salvini in with my firemouth and blue acara, the firemouth spent most of its time hiding. The second I took the salvini out, the firemouth came out of hiding, picked a fight with the larger blue acara, won, and took over the tank.
A while later when my convict caught up in size and started asserting itself the firemouth allied itself with the blue acara, since the firemouth had trouble standing up to the convict by itself, but the convict would back down from the larger blue acara.
The firemouth and the blue acara still have their little alliance going, protecting their third of the tank from the convict.
My experience with firemouths is that they can sort of be dicks. They'll claim whatever they can in terms of territory and hierarchy any way they can.
When I had my salvini in with my firemouth and blue acara, the firemouth spent most of its time hiding. The second I took the salvini out, the firemouth came out of hiding, picked a fight with the larger blue acara, won, and took over the tank.
A while later when my convict caught up in size and started asserting itself the firemouth allied itself with the blue acara, since the firemouth had trouble standing up to the convict by itself, but the convict would back down from the larger blue acara.
The firemouth and the blue acara still have their little alliance going, protecting their third of the tank from the convict.