Thursday, October 31, 2019

[Mammalogy • 2019] Rhinolophus andamanensis • Integrated Approaches to Identifying Cryptic Bat Species in Areas of High Endemism


Rhinolophus andamanensis Dobson, 1872

in Srinivasulu, Srinivasulu, Srinivasulu & Jones, 2019. 

Abstract
The diversity of bats worldwide includes large numbers of cryptic species, partly because divergence in acoustic traits such as echolocation calls are under stronger selection than differences in visual appearance in these nocturnal mammals. Island faunas often contain disproportionate numbers of endemic species, and hence we might expect cryptic, endemic species to be discovered relatively frequently in bats inhabiting islands. Species are best defined when multiple lines of evidence supports their diagnosis. Here we use morphometric, acoustic, and molecular phylogenetic data to show that a horseshoe bat in the Andaman Islands is distinct in all three aspects, supporting its status as a distinct species. We recommend investigation into possible new and endemic bat species on islands by using integrated approaches that provide independent lines of evidence for taxonomic distinctiveness. We provide a formal redescription of the taxon newly raised to species level, Rhinolophus andamanensis Dobson, 1872.

Fig 4. Live images (A-C) and holotype (ZSI Reg. No. 15561) (D) of Rhinolophus andamanensis Dobson, 1872.
Ear pinna and antitragus (A), frontal view of the noseleaf and three mental grooves (B), and lateral view of the noseleaf showing shape of the sella (C) and the holotype (D).

Rhinolophus andamanensis Dobson, 1872
 Homfray’s Horseshoe Bat.

Holotype: Rhinolophus andamanensis ZSI Reg. No. 15561, male, collected from South Andaman Island, Andaman Islands, India, 1872, by J. Homfray; specimen, and skull (damaged).

Diagnosis: A medium-sized bat with a forearm length ranging between 46.7–56.6mm. Ears tall and broad, with well-developed antitragus, tragus absent (Fig 4A). Horseshoe is broad and covers the whole of the muzzle, supplementary leaflet distinct; three mental grooves are observed on the lower lip (Fig 4B). When viewed frontally, sella is narrow above and wider below (Fig 4B). Superior connecting process bluntly rounded off, inferior surface slightly bent, inferior extremity curved downward (Fig 4C). Sella roughly half the length of the lancet. Lancet narrow, triangular and tapered to a point; has three distinct cells (Fig 4B). Skull robust with a condylocanine length of 21.97±0.53mm. The maxillary toothrow (cm3) measures 9.85±0.30mm. pm2 is small but in the toothrow. pm2 is in the toothrow, and is half the height of pm4 and one third the height of the canine. Baculum narrow and long, base distinctly trilobed, the shaft curving gently when viewed laterally.


Ecology: Little is known about the ecology of this species. Large colonies were found in limestone caves, forest caves, and sometimes in holes and hollows of large trees. It cohabits with Rhinolophus cognatus, Hipposideros diadema masoni, H. gentilis, H. grandis, and Myotis horsfieldii.

Distribution: Rhinolophus andamanensis is endemic to the Andaman Islands. It is distributed throughout the Andaman Archipelago—from North Andaman to Little Andaman.


Chelmala Srinivasulu, Aditya Srinivasulu, Bhargavi Srinivasulu and Gareth Jones. 2019. Integrated Approaches to Identifying Cryptic Bat Species in Areas of High Endemism: The Case of Rhinolophus andamanensis in the Andaman Islands.  PLoS ONE. 14(10): e0213562. DOI: 10.1371/journal.pone.0213562