Molecular phylogeography of Boophis tephraeomystax: a test case for east-west vicariance in Malagasy anurans

Vences, M. & F. Glaw (2002): Molecular phylogeography of Boophis tephraeomystax: a test case for east-west vicariance in Malagasy anurans. Spixiana 25/1: 79-84 Phylogenetic analysis of sequences of the mitochondrial 16S rRNA gene in the Malagasy treefrog Boophis tephraeomystax resulted in a clear separation of one clade corresponding to the populations from the east and northwest and a second clade comprising the populations from the west of Madagascar. Within each clade, the pairwise differentiation was 0-3 nucleotides, whereas differentiation between clades was 12-13 nucleotides. This phylogeographic structure correlates with bioacoustic and karyological differences between eastern and western populations. We consider the observed differences as indicative of separation on the species level, and revalidate Rhacophorus doulioti Angel, 1934 as Boophis doulioti to refer to the western populations hitherto assigned to B. tephraeomystax. B. tephraeomystax and B. doulioti are an additional example of a pair of sister species distributed allopatrically in eastern and western Madagascar. This pattern may have been caused by vicariant speciation in the course of past climatic shifts which led to more or less temporary isolation and fragmentation of western amphibian populations.