Too small, and the colours are too washed out to tell in my opinion.
Judging by Caudal fin pattern I'd hazard a guess at Geophagus altifrons 'Rio Tapajos', or possibly (and knowing mysterious ID Geophagus..), a member Geophagus surinamensis complex. Could be way off, time will tell. Personally, to me, it looks like an altifrons juvenile, but I'm nowhere near an expert.