Morpho-Functional Adaptations of the Lingual Epithelium of Two Bird Species Which Have Different Feeding Habits

摘要

The dorsal epithelium of the free portion of tongue of laughing dove, Streptopelia senegalensis (granivorous) is characterized by presence of well-developed keratinized epithelium with desquamate parakeratinized one which is covering the anterior part of the free portion. Highly keratinized and stratified epithelium is covering the ventral surface of the anterior third of the free portion of the tongue and forming the lingual nail. Laryngeal area is covered dorsally by non-keratinized squamous epithelium. Frenulum is covered by a transitional-like epithelium. Both the dorsal and ventral surfaces of the free portion of the tongue of the common hoopoe, Upupa epops (insectivorous) are covered by thin non-keratinized squamous epithelium except that covered the areas of lingual tubercles, lingual wings and lingual papillae, which are covered by epithelium furnished dorsally by detached keratin. The laryngeal area is covered by non-keratinized squamous epithelium. The frenulum is covered by non-keratinized stratified squamous epithelium. It has been summarized that the differences in the structures of the avian tongue reflecting the differences in the feeding habits. The epithelium covering the tongue of the laughing dove is constructed for high mobility (up-down movement) in comparison with the epithelium of the common hoopoe that depends on its first action of feeding on the movement of the jaws and beak.