My best guess is Port Acara (Cichlasoma portalegrense), but there are people much better at this than I am. It's tough to nail it down exactly with this pic though for two reasons.
1) He looks like he just pushed off so his fins are restricted to the body allowing him to glide.
2) I'd try to a photo that really shows what he looks like in direct light. Either this pic is a bit blurry or the lighting isn't good enough to really see the coloration.
If my guess is wrong, I can at least tell you that this fish is not an African Cichlid, it's definitely South or Central American.