If it is less than 3.5" or so, I would say a male FHM that isn't in spawning colors. I base this on the first ray of the dorsal fin is distinctly shorter than the next one, there is a fattening of the caudal fin at the base along the bottom and upper edges of it, these traits along with the general shape of the fish is indicative of a FHM male.
A rare FHM male may be almost 4" but that would be a freak. If the fish is longer then 4", well then I am pretty stumped and will have to reevaluate the picture.
