Phylogeography of the African Helmeted Terrapin, Pelomedusa subrufa: Genetic structure, dispersal, and human introduction

The African Helmeted Terrapin, Pelomedusa subrufa is currently recognized as a single species, and is found throughout sub-Saharan Africa, as well as on the Arabian Peninsula and in Madagascar. A preliminary genetic study of Pelomedusa based on mitochondrial and nuclear DNA is presented to determine the genetic diversity within Pelomedusa, and whether the disjunct populations are natural or anthropogenic. The monophyly of Pelomedusa is in question, as Pelusios may be nested within Pelomedusa. Within Pelomedusa there are three subgroups: Western, Eastern, and Southern. The Western clade is composed of two monophyletic groups divided by ecoregion, one through the Sahel region of Africa, and the other in the savanna region of West Africa. The Eastern clade contains a disjunct population on the Arabian Peninsula, and sequence divergence and divergence dating estimates indicate that this population was probably established through a natural dispersal event. The Southern clade includes a disjunct population in Madagascar, and this Malagasy population likely is the result of a recent human-mediated introduction, since sequence divergence compared to other individuals in the Southern clade is relatively low.