Ultrastructural Studies on the Tongue of Some Egyptian Lizards 1-Scincine Lizards Chalcides Oscellatus and Chalcides Sepsoides (Lacertilia, Scincidae)
Tongues of Egyptian lizards Chalcides ocellatus and Chalcides sepsoides are investigated under scanning and transmission electron microscope. Their tongues are divided into tip, anterior, middle and posterior regions. In C. ocellatus, the tip region is bifurcated and protected with strong, non-papillosed, keratinized epithelium. The lingual papillae are separating with wide trenches except in the middle region. Papillae of the anterior and posterior regions have serrated and imbricated ends oriented in the posterior direction. The surface epithelia is studded by tiny or reticular microvilli. Ultra-sections show that the imbricated portions have goblet cells rich in numerous secretory granules. The lamina propria of each papilla is provided with striated muscle fibers. The distribution and orientation of the lingual muscle fibers prove that the tongue is adapted for snipping, masticate and swallowing their praise. In C. sepsoides tongue, the tip region is slightly bifurcated. All lingual papillae have different shapes with narrow moats separating between them. Those of the anterior and posterior regions have free ends overlapped towards the anterior or posterior directions, respectively, while that of the middle region is not imbricated. The surface epithelia of the tongue has dispersed or aggregated microvilli. In the tongue of the C. sepsoides, new structures are described for the first time. At its ventral aspect, there is an accessory lingual muscle formed of numerous muscle fibers orient to the vertical, transverse or longitudinal directions. These orientations prove that the tongue is able to mash and suck the prey’s sherbets. At the end of the posterior region, there is a ciliated concave depression hosting a laryngotracheal organ, which has T-shaped crevice precedent by large fleshy highly ciliated lip supported by inflexible folds.