Scanning Electron Microscopy Study of the Dorsal Surface of the Tongue in the Slow Loris (Nycticebus coucang) and Pygma Slow Loris (N. pygmaeus)

The dorsal surface of the tongues of the Slow Loris and the Pygma Slow Loris were examined by employing scanning electron microscopy techniques. Three types of the papillae are present on their dorsal surface of the tongue: filiform, fungiform and vallate. The filiform papillae are located the apex and the body of the tongue, and we observed that each of them has a gustatory pore. The fungiform papillae, scattered singly among the filiform papillae, distribute mainly on the apex of the tongue. The vallate papillae are located along the diversing arms of the V-shaped boundary between the anterior and posterior regions of the tongue. In addition, no foliate papillae were observed. The morphological characteristics of the dorsal surface of the tongues in Slow Loris and Pygma Slow Loris are similar to each other.