geophagus id

I recently got 2 Geo brasiliensis in my 75G. I’m having a bit of trouble figuring out what’s going on. I had 1 female Geo Sveni about double their size and ended up having to remove her as these 2 were starting to bother her. They are about 3 inches each and were doing GREAT together. They made...

On photos is fish labelled as "Geophagus sp. rio Negro". Photos are made by mine friends who own this fish. This fish is common in local fish stores and fish tanks here (Czech republic and Slovak republic). But when I look on web sites and forums from other countries, this fish is extremely rare...