Detection of Cryptic Diversity in Malaysian Bats: Examples from Glischropus and Tylonycteris (Vespertilionidae)

The number of recognized bat species has increased rapidly in the recent years, mainly as the result of integrative approaches anchored on new molecular data sets. In many cases, species with wide distributional areas were found to harbour cryptic taxa. This applies to the Southeast Asian genera Glischropus and Tylonycteris which originally comprised only two species each. Currently, both genera are thought to include five and six species, respectively. Our karyological analyses from Glischropus and Tylonycteris specimens collected from Borneo revealed profound differences among conspecifics from the Peninsular Malaysia. The Bornean G. tylopus with 2n = 26 in the female karyotype differs clearly from the 2n = 31/30 (male/female) chromosomal complement observed in specimens from Peninsular Malaysia. Similarly, the T. pachypus specimen from Borneo with 2n = 30 is cytogenetically distinct from the 2n = 46 karyotype found in specimens from Selangor, Peninsular Malaysia. These findings challenge the assumption that Tylonycteris fulvida which showed 2n = 30 in Chinese specimens is present in Peninsular Malaysia. By incorporating data from the literature, we provide an updated chromosomal phylogeny for the genus Tylonycteris highlighting the need for further taxonomic revisions in the group.