Genetic evidence supporting the taxonomic separation of the Arabian and Northwest African subspecies of the desert hedgehog (Paraechinus aethiopicus)

Traditional subspecies call attention to differences between geographic populations with research potential, but their value is often in need of revision. Genetic data can be useful for evaluating the taxonomic validity of historical species and subspecies designations or for identifying morphologically cryptic divergent lineages worthy of further in-depth taxonomic study. The desert hedgehog (Paraechinus aethiopicus) has a wide but fragmented distribution in arid and semi-arid habitats from the northwest to the northeast of Africa and southwestern Asia, and its taxonomy is still unclear. We used mitochondrial (cytochrome b, Cyt b, and 12S ribosomal RNA, 12S) and nuclear (breast cancer type 1 susceptibility protein, BRCA1, and apolipoprotein B, Apob) DNA sequence data to assess the degree of genetic divergence between two of its three major proposed subspecies: Arabian (P. a. dorsalis) and Northwest African (P. a. deserti); this is the first molecular evaluation of the taxonomy of P. aethiopicus. Phylogenetic analyses, comparison of interspecific and intraspecific genetic distances observed across hedgehog species, and molecular species delimitation methods (distance-based clustering and tree-based), all indicate a level of genetic differentiation between dorsalis and deserti that is compatible with their taxonomic separation. Their divergence in the studied genes were consistently comparable to, or greater than, several intrageneric and a few intergeneric distances in hedgehogs. The Cyt b net Kimura 2-parameter distance between dorsalis and deserti was 10.8 ± 1.3%, which is about the mean between congeneric species in reviews of Cyt b distances for mammals. This study, as a test of the genetic distinctiveness of dorsalis and deserti, suggests that they represent evolutionarily significant units and flags them for future phylogeographic and taxonomic investigations.