hi mt, i've noticed in my BG and GSF that many general characteristics start early, i am not so sure, but would bet, they do for RES too......examples......
GSF: elongate body w/ overall greenish cast, emerald streaks on mouth and gill plate, roundish pec fin, much larger mouth (jaw line extends under eye)
BG: rounder body w/ overall bluish cast, vertical barring on body, small mouth (jaw line stops well forward of eye)
RES: (i am extrapolating here cause i havent seen a young one in my pond yet).....body style more elongated compared to BG w/ silverish cast, black and gray irregular mottling on body, very pointed pec fin, mouth larger than BG but much smaller than GSF
some pics would be nice to support this, but all i have in young fish are BG and GSF as follows:
BG
GSF
GSF
youngest RES pic i have
good luck......good question.....
