Thumb-pads up-a new species of thick-thumbed bat from Sumatra (Chiroptera: Vespertilionidae: Glischropus)

Insights into the formation and diversification of a novel chiropteran wing membrane from embryonic development

BACKGROUND

Through the evolution of novel wing structures, bats (Order Chiroptera) became the only mammalian group to achieve powered flight. This achievement preceded the massive adaptive radiation of bats into diverse ecological niches. We investigate some of the developmental processes that underlie the origin and subsequent diversification of one of the novel membranes of the bat wing: the plagiopatagium, which connects the fore- and hind limb in all bat species.

RESULTS

Our results suggest that the plagiopatagium initially arises through novel outgrowths from the body flank that subsequently merge with the limbs to generate the wing airfoil. Our findings further suggest that this merging process, which is highly conserved across bats, occurs through modulation of the programs controlling the development of the periderm of the epidermal epithelium. Finally, our results suggest that the shape of the plagiopatagium begins to diversify in bats only after this merging has occurred.

CONCLUSIONS

This study demonstrates how focusing on the evolution of cellular processes can inform an understanding of the developmental factors shaping the evolution of novel, highly adaptive structures.

Out of Southeast Asia: A new species of thick-thumbed bat (Chiroptera: Vespertilionidae: Glischropus) from Meghalaya, north-eastern India

Thick-thumbed bats of the genus Glischropus are currently composed of four recognized species from Southeast Asia, two of which were described in recent times. Among these species, G. aquilus is endemic to Sumatra, G. javanus is restricted to western Java, whereas G. bucephalus is widely distributed north to the Isthmus of Kra and G. tylopus is widespread south to this zoogeographic boundary. Two recently collected Glischropus specimens from Meghalaya state in north-eastern India extend the known distribution range of the genus westward into South Asia by ca. 1000 km. Morphological examination of these specimens and comparison with all known species in this genus revealed marked differences in colouration, dental characters and bacular traits. We therefore describe the Meghalaya specimens as a new species. The discovery of the new species from a forest patch adjacent to Nongkhyllem Wildlife Sanctuary from where another specialized bamboo-dwelling species (Eudiscopus denticulus) was reported recently also underscore the importance of the area from a conservation point of view.

A new genus of vespertilionid bat: the end of a long journey for Joffre's Pipistrelle (Chiroptera: Vespertilionidae)

Knowledge as to the taxonomic status of enigmatic bat species often is hindered by limited availability of specimens. This is particularly true for aerial-hawking bats that are difficult to catch. One such species, "Hypsugo" joffrei, was originally described in Nyctalus due to its long and slender wings, but subsequently transferred to Pipistrellus, and most recently to Hypsugo, on the basis of morphology. Analysis of newly available material, which more than doubles the known specimens of this taxon, demonstrates that it is morphologically and genetically distinct from all other bat genera. We accordingly describe it as belonging to a new, monotypic genus. We provide a detailed description of its external and craniodental traits, measurements, and assessment of genetic relationships, including barcode sequences to facilitate its rapid identification in future. The new genus belongs to a group that includes the recently described Cassistrellus, as well as Tylonycteris, and its closest relative, Philetor. We also describe the echolocation calls emitted by members of the taxon in different situations, which may facilitate finding them in previously unsampled locations. Based on the new data, the species occurs from Nepal to North Vietnam and China, which suggests that it could be more widespread than previously thought.

A checklist of the bats of Peninsular Malaysia and progress towards a DNA barcode reference library

Several published checklists of bat species have covered Peninsular Malaysia as part of a broader region and/or in combination with other mammal groups. Other researchers have produced comprehensive checklists for specific localities within the peninsula. To our knowledge, a comprehensive checklist of bats specifically for the entire geopolitical region of Peninsular Malaysia has never been published, yet knowing which species are present in Peninsular Malaysia and their distributions across the region are crucial in developing suitable conservation plans. Our literature search revealed that 110 bat species have been documented in Peninsular Malaysia; 105 species have precise locality records while five species lack recent and/or precise locality records. We retrieved 18 species from records dated before the year 2000 and seven species have only ever been recorded once. Our search of Barcode of Life Datasystems (BOLD) found that 86 (of the 110) species have public records of which 48 species have public DNA barcodes available from bats sampled in Peninsular Malaysia. Based on Neighbour-Joining tree analyses and the allocation of DNA barcodes to Barcode Index Number system (BINs) by BOLD, several DNA barcodes recorded under the same species name are likely to represent distinct taxa. We discuss these cases in detail and highlight the importance of further surveys to determine the occurences and resolve the taxonomy of particular bat species in Peninsular Malaysia, with implications for conservation priorities.