Global DNA methylation, as estimated in blood samples, does not correlate with variations of body condition, anatomical features and hematological parameters in American bullfrogs (Lithobates catesbeianus) kept captive under distinct environmental conditions.

Different levels of Global DNA Methylation (GDM) could have facilitated the emergence of new species, without relying on gene mutations, through promoting ontogenetic phenotypic plasticity. If this assertion was correct, one could expect individuals of the same species living under distinct environmental conditions to be genetically similar, but having different GDM levels and being phenotypically divergent. We tested this presumption by studying the relationship between variability of functional morphological traits and GDM levels in American bullfrog (Lithobates catesbeianus), in green houses located in two geographical sites. Our analyses revealed that body linear morphometry, skull geometry, scaled mass index, packed cell volume and neutrophil counts differed significantly among males and females within and between localities. GDM, nonetheless, was rather similar among sex and locality groups. These results show that levels of GDM, at least under our experimental contexts, does not correlate with functional morphological trait variability.