Do you love big bluegill?
RIC;; THE BEST GUYS TO ANSWER THIS ONE IS;; TONY LIVINGSTON;; AND WALT FOREMAN !! BOTH OF THESE GUYS; HAVE PROABLY ; FORGOTTEN MORE ABOUT BLUE GILL; THAN MOST OF US KNOW !!
I used to fish a pond that was stocked with BG x GS Hybrids.
I've learned a few things over the years. Hybrid sunnies, OF ANY STRAIN, are fertile, and will spawn and produce offspring. Most hatcheries sell the BG x GS Hybrids as the Hybrids are about 95% male. So, if the BOW is stocked with only the Hybrid, you'll see very little reproduction, due to the low number of females. However, ALL the males will still prepare beds, so it will look like they are spawning.
I have caught a few F2 generation fish, from the same pond. These fish had the body size and shape of a good-sized Green Sunfish, but they were colored more like a Black Crappie with a little bright orange on their fins. Weird looking fish.
I've been told that if you are stocking BG x GS Hybrids, you have to kill the pond every few years and restock, to keep the F2 and F3 fish from taking over.
I've also fished a creek that had some naturally-occuring BG x GS hybrids. It does happen! That particular creek was LOADED with fish. I could always count on catching some Greenies near the bank, and 'gills out in the middle. The ocassional LMB and/or Channel Cat just added some spice :) UL fishing and/or fly fishing in that creek was always a blast.