Morphology of the dorsal lingual papillae in the lesser mouse deer, Tragulus javanicus.

The dorsal lingual papillae of the lesser mouse deer were studied morphologically using light and scanning electron microscopy. Four types of papillae, filiform, fungiform, vallate and foliate, were observed. Filiform papillae consisted of larger main papillae with smaller secondary papillae on their anterolateral aspects. Secondary papillae were well distributed over the anterior two-thirds of the tongue, but were very rare or absent in the posterior third. Fungiform papillae were distributed among the filiform papillae, being larger and more abundant on the tip of the tongue. Vallate papillae were round-flat or long-flat, surrounded by a prominent circular groove and a thin annular pad. An important finding was the presence of distinct and prominent foliate papillae on the posterolateral sides of the tongue. Keratinisation of the covering stratified squamous epithelium was relatively weak. Taste buds were observed in the epithelium of the fungiform, vallate and foliate papillae. The lingual papillae of the lesser mouse deer showed some characteristics that differed from those reported for domestic ruminants. These may be related to the feeding habits and the type of food eaten by this species.