looks exactly like my red snapper but grey, this is oreochromis mossambicas, but they can live in almost any type of water conditions, most temps, they eat anything and are aggresive little bastards, and they breed like crazy. so its deffinatly a type of tilapia/snapper
its a dogtooth snapper, lujanus jocu. in florida they are called mangrove snapper suggesting gray snapper but dogtooth snapper have big front fangs, as they are fishh specialists in diet. they get too big for most aquariums.