HISTOCHEMICAL ANALYSIS OF THE TONGUE IN NEOTROPICAL FRUGIVOROUS BATS (MAMMALIA – CHIROPTERA) WITH REPORT OF EPITHELIAL PIGMENTATION

Abstract

The tongue is regarded as a key organ for bats, since the specialized characters are used for taxonomic and systematic purposes, cladistic studies, and elucidation of patterns of eating habits. This study aimed to characterize morphologically the tongue in the species Artibeus lituratus, Artibeus planirostris, Artibeus obscurus, and Dermanura cinerea, and to report the first evidence of melanin in the lingual epithelium of bats. We used 20 specimens collected in the municipalities of Vitória de Santo Antão and Sirinhaém, in Pernambuco State, Brazil. The tongues were extracted and submitted to routine histological techniques, stained with hematoxylin and eosin (HE) and Fontana-Masson. In the four species, the keratinized stratified pavement epithelium was observed, but with the presence of melanin granules on the basal layer only in the species A. lituratus, A. planirostris, and A. obscurus, evidenced through the Fontana-Masson staining technique. The melanin found in the tongue of these species is characterized as the first record for the order Chiroptera and it may be related to oral asepsis, and/or inhibition of toxic substances observed in plants. Therefore, there is a need for further studies, aiming to improve our knowledge of the function of pigment in this organ.
Keywords: Artibeus; Dermanura; melanin; bats; lingual morphology.