Gross anatomy and scanning electron microscopic study of the tongue of Egyptian Dabb lizard (Uromastyx aegyptia) in relation to feeding habits

Abstract

Introduction: The tongue is considered a key innovation in the evolution of a terrestrial lifestyle. Methods: The adult animals were sacrificed with sharp razor blade. The heads were separated to remove out tongue from its root after separation of upper and lower jaws. Results: The tongue of Uromastyx aegyptia is divided into fore-tongue with its anterior tip, mid and hind tongue. The anterior region of the fore-tongue is bifurcated. The lingual papillae are posteriorly imbricated and separated by wide trenches. The epithelial cells are provided by tiny microvilli. In the mid-tongue, the papillae are not imbricated and have strong rhombus-shaped with narrow trenches. The microvilli of the surface epithelium have reticular pattern and attached with each other by microridges. The papillae of the hind-tongue have a rectangular shape with deep serrated ends. The imbricated part in the anterior portion of each papilla is provided with numerous taste buds. The striated muscle fibers are distributed in the lamina propria of the lingual papillae and the tongue connective tissue. Conclusion:The distribution and orientation of the muscle fibers prove that the tongue is able to catch the prey by biforked tip and facilitate the swallowing behavior.