Diversity of Ridged Frogs (Anura: Ptychadenidae: Ptychadena spp.) in wetlands of the upper Nile in Rwanda: Morphological, bioacoustic, and molecular evidence

摘要

We investigated the distribution of species of the genus Ptychadena at nine sites at the upper Nile and its catchment in Rwanda. For species delimitation, we chose an integrative approach, combining morphological and bioacoustic data and DNA barcoding (mitochondrial 16S rRNAgene). We identified three species using independent evidence from the three different data sets: Ptychadena anchietaey Ptychadena poro- sissima,and a species of the Ptychadena mascareniensis group. The latter is undistinguishable genetically, bioacoustically,and morphologically from populations from Uganda, Kenya, and Egypt. We resurrect the name Ptychadena nilotica for these populations. The species differs strongly genetically from topotypic P. mascareniensis, and from clades referred to as P. cf. mascareniensis from Western and Central Africa. Morphologically, the three Rwandan species can be differentiated by their quantitative morphometries (discriminant analysis, success rate: 98.3%) and by a number of qualitative characters of external morphology which are useful for identification in the field. The specific features of the advertisement call differ unequivocally among the three species and allow detection and identification in the field. We also provide quantitative descriptions of temporal and frequency structure of the release calls of two of the species and the distress calls of all three species. Finally, we compare the 16S sequences obtained from Rwandan specimens with those deposited in GenBank to estimate geographical distribution of taxa in Africa.