Molecular systematics of Australian rhinolophid bats (Chiroptera : Rhinolophidae)

Abstract

Genetic variation in two morphologically distinct species of Australian Rhinolophus, R. megaphyllus, and R. philippinensis, and a third putative species (‘the intermediate’) were examined using allozyme electrophoresis and sequencing of the mitochondrial DNA (mtDNA) control region with the aim of resolving their taxonomic status. The surprising result was that no fixed allozymic differences and low allozyme divergence existed among these three taxa over 45 loci examined. In contrast, levels of intra-generic divergence among eight species of Rhinolophus showed up to 50% fixed allozyme differences between species, indicating that low allozyme divergence was not a common 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 from Sabah, New Guinea, and Australia were represented by distinct mtDNA clades and that the two species are polyphyletic. These data suggest a reclassification of the different geographic populations of R. megaphyllus and R. philippinensis as separate species on the basis of a phylogenetic species concept. Within Australia, three distinct mtDNA clades were found, one of which showed ‘the intermediate’ in paraphyly with R. philippinensis from Queensland, but does not resolve the taxonomic status of ‘the intermediate’. Two mtDNA clades were also found representing R. megaphyllus from Queensland and R. megaphyllus from Victoria and New South Wales respectively. The finding of genetic subdivision along the east coast of Australia in an apparently continuously distributed bat species raises questions of the origin and historical biogeography of these bats in Australia.