Ecomorphological implications of the microstructures on the tongue of the fawn roundleaf bat, Hipposideros cervinus (Chiroptera : Hipposideridae)

The morphology of the lingual papillae on the tongue of the fawn round-leaf bat (Hipposideros cervinus) was studied by scanning electron microscopy to determine its functional role in feeding ecology. Both mechanical and gust atory papillae were detected on the lingual surface. Large pronged papillae at the lingual apex provide a rake-like surface that facilitates quick ret rieval of insect prey that may be trapped by the wing and tail membranes. T hese papillae also provide additional traction and act as a barrier, preven ting the insects from escaping. Additional securing and gripping structures include the crowned filiform papillae situated on the anterior half of the tongue. Conical papillae on the lateral and medial aspects of the lingual root serve as a protective barrier to the lingual mucosa, and aid in direct ing insect fragments towards the oesophagus. The pair of small vallate papi llae at the lingual root may reflect a compromise in gustatory potential. T aste perception may be a secondary feature in food selection of this bat an d fungiform papillae may resume a more important mechanical function. Colle ctively, the lingual papillae of H. cervinus portray an adaptation to mecha nical manipulation of food, instead of taste perception, which may not be o f primary importance to insect feeders.