This is an adult southern banded watersnake, Nerodia fasciata fasciata, found in the waters of the "canal line" at Grand Bay WMA just east of Valdosta, Georgia. It should be noted that I believe this snake was a hybridized decedent of both N. f. fasciata (the southern banded watersnake) and N. f. pictiventris (the Florida banded watersnake). I counted 126 ventral scales on this individual and that falls in line with N. f. pictiventris; however, this area is in the formal range of N. f. fasciata. Hybridization is common between these two subspecies. Because of range and the dominance of the southern banded subspecies in the area, I'm tagging it N. f. fasciata. Just recognize that there's likely some pictiventris DNA thrown into the mix!
For info on differentiating the subspecies, see Clay 1938: http://www.cnah.org/pdf_files/1021.pdf. An old document, but it does provide scale-count methods for distinguishing the subspecies. I'm counting Nerodia ventral scales (when I'm able) to "test" Clay's identification results.
~ janson jones,
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