Molecular systematics of Australian rhinolophid bats (Chiroptera : Rhinolophidae)

Genetic variation in two morphologically distinct species of Australian Rhi nolophus, R. megaphyllus, and R. philippinensis, and a third putative speci es ('the intermediate') were examined using allozyme electrophoresis and se quencing of the mitochondrial DNA (mtDNA) control region with the aim of re solving their taxonomic status. The surprising result was that no fixed all ozymic differences and low allozyme divergence existed among these three ta xa over 45 loci examined. In contrast, levels of intra-generic divergence a mong eight species of Rhinolophus showed up to 50% fixed allozyme differenc es between species, indicating that low allozyme divergence was not a commo n feature of the genus and that the three Australian taxa are likely to be monophyletic and recently diverged. Phylogenetic analyses of mtDNA sequence data revealed that populations of R. megaphyllus and R. philippinensis fro m Sabah, New Guinea, and Australia were represented by distinct mtDNA clade s and that the two species are polyphyletic. These data suggest a reclassif ication of the different geographic populations of R. megaphyllus and R. ph ilippinensis as separate species on the basis of a phylogenetic species con cept. Within Australia, three distinct mtDNA clades were found, one of whic h showed 'the intermediate' in paraphyly with R. philippinensis from Queens land, but does not resolve the taxonomic status of 'the intermediate'. Two mtDNA clades were also found representing R. megaphyllus from Queensland an d R. megaphyllus from Victoria and New South Wales respectively. The findin g of genetic subdivision along the east coast of Australia in an apparently continuously distributed bat species raises questions of the origin and hi storical biogeography of these bats in Australia.