Hey codeline, I have no idea, terribly sorry. But They look cool, if they would to breed I would love to get some from you. Sorry couldn't help though.
My guess would be one of the poorly described "acaras" currently placed in the "Cichlasoma" genus. If they're wild, then finding their collection location is the best bet for identifying them.
It does appear to be one of the true acaras, Aequindens ... looks closest to A. viridis to me, but could also be one of the various A. tetramerus color morphs. Collection data would deffinately help.