Originally Posted by Bill Cody
That fish in the picture has no evidence of any ear tab, so how can anyone say with confidence what specie it is. RES and BG look very much alike when they are small enough the ear tab is not even apparent yet. The fish also to me looks to be stunted and not growing well (food shortage &/or just runts) ) because of the enlarged eye. Eyes continue to grow when food is limited for body growth. I think that fish is one of the slow growers (1"-2") that you bought from Stoney Creek as RES this spring. If it turns out to be a BG then IMO their RES were contaminated with BG.

One thing that would help identify the specie is to get a good picture of the gill rakers. BG will have long rakers and RES have short rakers. Another character that I use to separate BG from RES is the pectoral fin is longer for the RES. However it requires a fair amount of experience and numerous comparisons to use this feature.
Curious about the stunted and large eye comment? Granted I stocked CNBG but all of them had large eyes like that and they are far from stunted