Light and scanning electron microscopy of the tongue of a degu (Octodon degus).

The tongue of an adult degu was examined by light and scanning electron microscopy. It consists of an apex, corpus, and radix and contains a lingual prominence. The aim of this study was to describe the course of muscle fascicles of the proper lingual muscle, the presence and nature of the lingual salivary glands, and particularly the appearance and distribution of the lingual papillae. Three major types of papillae have been observed: filiform, conical, and vallate. The dorsal surface of the lingual apex extends in caudally bent filiform papillae with two spines. The lingual corpus bears long filiform papillae with a single tip. The lingual radix contains crown-like papillae in the region of the prominence and conical papillae in the remaining areas. Two oval vallate papillae were discovered caudally on the lingual radix. This first description of the lingual structures in a degu could be used for comparative studies or as basic data for differentiation of lingual morphology in this species.