That is their common name. They are a subspecies of BG which originated in Florida. Not a filer. I have never heard anyone seriously contend that CNBG will get twice as big as regular BG. They are only one of three recognized subspecies of bluegill (lepomis macrochirus). Coppernose (lepomis macrochirus purpurescens) is native to Peninsular of Florida. Coppernose bluegill have 12 soft rays on their anal fin as opposed to 11 soft rays found on the regular bluegill. Coppernose have fewer but wider vertical bars on their sides than do regular (common or native ) bluegill. Coppernose also have orange margins to their fins. Male coppernose has a broad copper band above the eye or forehead and are prominent during spawning season. Reproduction of the Coppernose is about the same as with most all bluegill.