Interesting observation snrub.
When I catch GSF I don't know how to determine its gender. I once caught a male that I though for certain was a female because its belly was so distended. It was a male however and its gullet was utterly full with a 2 inch cray, a small fish that I think was YOY GSF., and a fair amount of gunk that I couldn't identify. They hit inline spinners very well and I wonder if they don't prefer fish over insects.
I wonder which tends to grow larger, the male or female GSF?
