I acquired a young group a few months ago from Jeff Rapps. They were labeled as G. brokopondo and collected from Lake Brokopondo. However, soon after they arrived, I noticed that they seemed to have black markings on the operculum, although it was much fainter than some other Geophagus species I've kept (e.g. G. dicrozoster and G. winemilleri). They also have the black "throat" similar to G. winemilleri, but again quite a bit fainter. I thought at the time that they were probably G. brachybranchus instead, although only G. surinamensis and G. brokopondo were found in that area (Kullander and Nijssen, 1989).
Well, as they matured over time, the operculum mark became fainter and fainter. Now it's not always visible, and seems more like a discontinuation of the blue spangle on the operculum than a actual black mark. Some other characteristics also look nearly identical to G. brokopondo as described by Kullander and Nijssen (1989).
A couple more observations:
- The two lateral bars immediately posterior of the lateral spot are very closely spaced, sometimes giving the impression of a wider but bisect bar.
- They are typical delayed mouthbrooders, and spawn on river rocks. Wiggling larvae are picked up on the third day and held by both parents.
I'm happy with whatever they are, but I do hope to be able to find out
When they first arrived:


More recent pictures:
Dominant male:


Dominant female:



