Take a better picture of the face. Do I see a black marking on the cheek? If so, it is not G. altifrons or G. abalios. Either way, you may have an issue with the firemouths because they occupy the same area of the tank and are essentially like the Central American version of Geophagus. There was just a thread a few days ago about a firemouth harassing a geo.
Also, geos seem more comfortable when you keep them in groups.