IMO it is much easier to use urogenital features during pre and post spawning season versus during mid summer and fall when openings have had time to reshape back to more normal shapes.
Of course, but the idea is there are physical differences during other times of year too albeit perhaps not as pronounced. My hope is the tank fish will be a better test as not only are they shy of a year old, they haven't mutured sexually like fish that were winterized. There are definitely some smaller fish in the tank that I will bet are males.
However I will also take pics of female fish in mid summer and if we can get it done of marked fish in Scott's pond as I won't have any males here.
