Genetic Variation in Cottonmouth 57 



Fig. 1. Populations of A. piscivorus sampled for electrophoretic study. 1 = New- 

 port News, 2 - Hopewell, 3 r Sea Shore State Park, 4 = Gum Swamp, 5 = 

 Northwest River, 6 = False Cape State Park. 



Starch gel electrophoretic techniques using the basic procedures of 

 Selander et al. (1971) were used with the following modifications: 

 albumin, hemoglobin, general proteins, and esterases were best demon- 

 strated on the Poulik buffer, while all other enzymes were isolated on 

 gels using the Tris-Maleic acid buffer. All gels were 12.5% starch (Elec- 

 trostarch Lot 307, Otto Hiller, Madison, Wisconsin). 



Isozymes of various proteins were designated in order of decreasing 

 anodal mobility. Alleles present at polymorphic loci were designated 

 alphabetically by a superscript following the locus designation. Nei's 

 (1972) index of genetic identity was used to compare genetic similarities 

 between populations, and mean heterozygosity per individual (H) was 

 calculated for each population. 



RESULTS 

 Of the 29 protein loci examined in this study, 23 were found to be 

 monomorphic in all individuals examined. These loci included: albumin, 

 hemoglobin, three general proteins, three esterases, two malate dehy- 

 drogenases, two lactate dehydrogenases, two phosphoglucomutases, one 

 phosphoglucose isomerase, a-glycerophosphate dehydrogenase, gluta- 

 mate dehydrogenase, two superoxide dismutases, isocitrate dehydroge- 

 nase, 6-phosphoglucose dehydrogenase, sorbital dehydrogenase, and 

 glutamate oxaloacetate transaminase (Got-1). Only three loci were poly- 

 morphic; their gene frequencies are listed in Table 1. 



