Additional Evidence for the Specific Status of Nerodia 
cyclopion and Nerodia floridana (Reptilia: Colubridae) 
William E. Sanderson 1 
Museum of Natural Science 
Louisiana State University 
Baton Rouge, Louisiana 70893 
ABSTRACT — Preserved specimens were used in a morphological 
comparison of Nerodia cyclopion and N. floridana. Data included 
counts of head and body scales and body scutes as well as mea- 
surements of head scale dimensions. Comparisons of these data re- 
vealed significant differences in the numbers of ventral scutes, 
subcaudal scutes, and dorsal scale rows. Discriminant analysis of 
head scale measurements proved to be a reliable tool separating 
these taxa and revealed no evidence of gene exchange. I concur 
with the recent elevation of the two taxa to full species; the two 
species are at least parapatric in the western Florida Panhandle. 
Two subspecies of the green water snake, Nerodia cyclopion 
(Dumeril, Bibron, and Dumeril, 1854) have been recognized since 
the description of N. c. floridana by Goff (1936). Goff (1936) documented 
that, on the basis of ventral coloration, numbers of ventral and 
subcaudal scutes, numbers of infralabial scales, and relative tail lengths, 
the eastern form (N. c. floridana ) could clearly be separated from 
the western form (N. c. cyclopion). Goff (1936) speculated that 
intergrades between Nerodia c. cyclopion and N. c floridana would 
be found somewhere between Mobile, Alabama, and Leon County, 
in the Forida Panhandle. He had no specimens from this area, how- 
ever, and so had no direct evidence for distributional contact or 
intergradation. 
Serological and immunoelectrophorectic comparisons within the 
genus Nerodia led Pearson (1966:8) to comment that “a low rela- 
tionship between N. c. cyclopion and N. c. floridana indicates that 
a re-evaluation of their status as subspecies should be considered; 
elevation to full species is suggested.” Mount (1975:208) cited lo- 
calities for both cyclopion and floridana from Baldwin County, Ala- 
bama, and stated that “clear evidence of intergradation ... is 
lacking,” although he noted that specimens from extreme southeast- 
ern Baldwin County appeared to be intermediate on the basis of 
ventral coloration. Lawson (1987) reported the results of molecular 
studies of the New World natricines, in which he proposed specific 
1 Present address: Asheville High School, 419 McDowell Street, Asheville, North 
Carolina 28803. 
Brimleyana 19:83-94, December 1993 
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