In my opinion, the bearding has very little to do with differentiating gender. Male Gold Saums typically display a high level of reticulation and color within their fins (especially the dorsal and caudal fins). Even a smaller size, males will usually already start to display this trait. I've posted two of my pictures below. They are both males. Notice the reticulation in the fins on both specimens. These fish are both around 3-4" in the pics (the first picture being a GT that I no longer have, the second picture is a GT I'm currently growing out).