Morphological Variation in Pseudemys 



123 



(f) 



95 0_ 



900_ 





F 









c 







R 



















F 



C 



50 



65 



75 



AA 

 Fig. 12. Graph of lateral angle of carapace (SA) versus angle of anal scutes 

 (A A). Symbols are defined in Fig. 10. 



definition of the subgenus Ptychemys that redbelly turtles (including P. 

 rubriventris) have posterior marginals without a notch. Of the P. 

 rubriventris we examined, 62% had posterior marginals that were 

 serrated (offset at seam) and clearly notched. Ward (1984) and Weaver 

 and Rose (1967) reported that the redbelly turtles (in contrast to P. 

 concinna and P. floridana) have a strongly rugose carapace (Fig. 17), 

 occasionally even as juveniles. In our sample, we found pronounced 

 carapacial rugosity in 22% of the P. concinna, 45% of the P. floridana, 

 and 49% of the P. rubriventris. These rugosities were observed exclusively 

 in large (old) adults. Ward (1984) reported that the inguinal scute of P. 

 floridana (in contrast to P. rubriventris and P. concinna) lacks any 

 black markings. We found that 74% of the P. floridana in our sample 

 had black markings on the inguinal scute. However, these markings are 

 usually absent in P. f peninsularis (personal observation). Ward also 

 reported that inframarginal spots posterior to the bridge are mostly 

 confined anterior to the seam in P. floridana. In 40% of the P. floridana 

 we examined, these inframarginal spots broadly overlap the seams. 



In old male Pseudemys from the Atlantic drainage areas, melanism 

 was detected in 2% of the P. floridana, 6% of the P. concinna, and 29% 

 of the P. rubriventris. Melanism in P. rubriventris was not only more 

 frequent, but also more complete compared with the other two species. 



