FT check to see if I am right and post here when you know. I bet those BG grow 2 inches before summer ends and that they spawn this summer in your location with a new pond. The growth rates are good (normal).

Like Bruce and Bill based on the pics I would not put them in an all male pond. By July you should be able to tell much better on these fish. A few days before the full moon in late July fish on the BG beds and you will be able to tell which are males.