Phylogenetic relationships of African green snakes generaPhilothamnus and Hapsidophrys) from Sao Tome, Principeand Annobon islands based on mtDNA sequences, andcomments on their colonization and taxonomy

摘要

Mitochondrial sequences (16S rRNA and cytochrome b) of the colubrine snake genera Philothamnus and Hapsidophryswere analysed. Samples were obtained from three volcanic islands in the Gulf of Guinea. The main objective was to inferphylogenetic relationships between the taxa and to trace back the colonization patterns of the group. Both insular species,Philothamnus girardi and Philothamnus thomensis, form a monophyletic unit indicating a single colonization event ofone island (probably Sao Tome) followed by dispersal to Annobon. Genetic divergence was found to be relatively lowwhen compared with other Philothamnus species from the African mainland, but sufficient to consider the two taxa asdistinct sister species. Here we also present evidence on the distinct phylogenetic position of Hapsidophrys sp. fromthe island of Principe, which should be considered as a distinct species, Hapsidophrys principis, a sister taxon of H.smaragdina.