Serum Protein Variation in an Interspecies Hybrid Swarm of Turtles of the Genus Pseudemys

Abstract

On the basis of external morphology and serum protein electrophoretic patterns, it is concluded that a sample of turtles collected from Broad Acres Lake, Richmond County, North Carolina, was drawn from an interspecies hybrid swarm, Pseudemys floridana X P. rubriventris. Three specimens, 2 from the Broad Acres Lake popla-tion, one from Lake Phelps, Washington County, North Carolina, on the basis of 9 characteristics that differ in the two species, were judged to be interspecies hybrids of P. floridana and P. rubriventris. This conclusion was supported by electrophoretic analyses of their serum proteins which revealed the presence in reduced concentration of a fast-moving globulin fraction characteristic of the sera of P. floridana and not present in that of P. rubriventris. Morphological variation in the hybrid swarm sample ranged from specimens not differentiable from P. floridana to 2 rubriventris-like individuals which, however, showed clear indications of genetic introgression from floridana. While floridana traits predominated in the sample, most individuals showed some evidences of rubriventris introgression, suggesting a high degree of assortment and recombination of the available genetic material. Quantitative variation in the fast-moving globulin fraction (characteristic of floridana) was found to range from absence of the component in 5 individuals (characteristic of rubriventris) to some patterns not differentiable from those of floridana. Mean concentration of the fast-moving component as well as mean total protein per unit vol. of sample was found to be less for the hybrid groups than for P. floridana. No correlation was found between species characteristic morphological traits and serum protein patterns.