Systematics of the genus Ptychadena boulenger, 1917 (Anura: Ptychadenidae) from democratic Republic of the Congo

This thesis increases the scope of previous phylogenetic analyses that revealed high levels of genetic differentiation within the anuran genus Ptychadena. Herein, I increase sampling of Central African populations of Ptychadena by over six times to examine their relationships to other African populations and to search for cryptic species. This study represents the most comprehensive molecular phylogeny of Ptychadena to date. A total of three mitochondrial (12S, 16S, and cyt b) and two nuclear (RAG1 and rhodopsin) genes were sequenced for 67 specimens of Ptychadena. Maximum parsimony, maximum likelihood, and Bayesian analyses were conducted. These analyses revealed a great deal of genetic diversity in the genus Ptychadena, suggesting that many species have been separated into distinct genetic lineages that will be recognizable as distinct species as some point. There are five genetically distinct lineages of P. mascareniensis sensu lato, three of which occur in the DRC. Multivariate analyses of morphometric and meristic data did not reveal any distinct morphological differences between any of the clades except P. mascareniensis sensu stricto in Madagascar. Based on habitat structuring, two of these distinct lineages, a savannah-dwelling lineage and a forest-dwelling lineage, should be recognized as distinct species under the names P. nilotica and P. marchei, respectively. The formation of the Albertine Rift combined with subsequent climatic shifts that increased habitat heterogeneity likely led to the establishment of these savannah and forest forms of P. mascareniensis