Bat facial and lip projections: Unique integumentary morphology

Abstract

We examined the morphology of chin and lip facial projections of seven species of Phyllostomid and Noctilionid bats utilizing scanning electron microscopy and light microscopy of immunohistochemical and stained paraffin-embedded sections. Results showed that lip and chin facial projections were composed of glabrous skin except for some chin projections of Noctilio leporinus that were composed of haired skin. All projections contained a rich and diffuse concentration of nerves that were associated with dermal papillae and epidermal rete pegs that contained Merkel cell-neurite units and a diffuse network of epidermal free nerve endings. The existence of physically extended anatomical structures that contain a variety of receptor sensory units and their associated modalities must be important to be present throughout this diverse group of bats. These facial projections include a unique neural arrangement, but their specific functions remain unknown.