CNBG, Lepomis Machrochirus Purpurescens, are a subspecies of Northern strain BG, Lepomis Machrochirus Machrochirus. They share many of the same qualities and preferences, with a few exceptions, the most notable being the CNBG intolerance for colder water, as jludwig mentioned. They appear to be the faster growing of the two strains, and I have seen it reported that they will achieve a larger size than the northern strain. The recent pictures posted over at BBG by Bruce Condello, showing northern strain fish pushing the three pound mark does tend to make one wonder, however.
They can display a distinct copper colored spot, or band on their noses, from which they get their name.
