The surinamensis can be hard to tell apart the differant species. My guess would be altifrons as well, doesn't quite look like promixus or abalios. Deffinately not taeniopareius or surinamensis.
Unless it was imported from Germany, it's deffinately not a surinamensis. They are restricted to a country that does not commerically export fish.
Could be a megasema like tennisboi 87 suggested. Still leaning towards altifrons though, it usually the one most often sold as surinamensis (kinda like most Satanoperca leucosticta are sold as jurupari).
Agreed, but I doubt people are slipping past the border into French Guiana to collect Geo's either. It's illegal to collect and export any fish in French Guiana, and the true surinamensis is restricted to that country. I have read somewhere that some crazy germans did illegally collect and export some Guanacara geayi back to Germany, so in theory they could have done the same with the surinamensis. But those are long odds.
But then surinamensis is the common name for pretty much all the Geophagus species. So in that sense it is a surinamensis, that's just not what species it is (probably).