30 miles east of me, we stocked fish from Harbin (CNBG in question) they have done very well in 2 of the coldest winters on record.
BUT.. as ewest pointed out to me, the growth potential of CNBG may never be seen in our climate.
The CNBG I stocked out in my pond are obvious when caught but off-spring is another thing.
I trap BG every day of the summer, there is always variation in colors-especially the opercular tab-some are just a black border (outline) instead of solid black. I haven't spent any time counting anal fin rays or trying to determine the differences, if there is any.
The days are short, projects are many. I can try and get some side pics of these fish for others to view.