I have a similar story to relate. The first time I stocked hsb from Todd Overton I bought the smallest ones he had available. The same thing happened to them that happened to your Gams. Some of them did survive the attack by the lmb but many did not. It would have been quite a show to watch as the hsb were coming out of the water trying to escape the lmb had I not just spent three hours driving and two dollars for each fish.