If it is a pure GSF the corner of the mouth when closed will come back to the front of the eye. Hard to tell in your picture how big the mouth actually is.

I have a few hybrids mixed in (not on purpose) in my main pond. Most of them as they have been caught have been transferred to my old pond where I already have GSF. The hybrids look so much like GSF with all the same markings sometimes when I re-catch one in the old pond I question myself if they are GSF or a hybrid. But then I catch a full blooded GSF and there is no question. Both the hybrids and the GSF look pretty much the same (but most of my hybrids are 8"+ now and biggest GSF to date has been 7.5) but the hybrid has a little taller profile and the mouth of the GSF is about a third larger for the same length fish. At least in the hybrids I have.

GSF will have very long first row of gill rakers also.

If you hold a GSF mouth fully open, it will be about the same mouth size as a similar length LMB. Hybrids, BG or RES will not have nearly as big of mouth.

Last edited by snrub; 10/27/14 10:47 PM.
John

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