[SEM study on the dorsal lingual surface of the nutria, Myocastor coypus].

The dorsal lingual surface of prenatal and postnatal nutria was examined by scanning electron microscopy (SEM). Filiform (Fi), fungiform (Fu), foliate (Fo) and vallate papillae (Va) were observed. The Fi differed in morphology by their location on the tongue and could be classified into 3 types: 1) conical, 2) long, and 3) short filiform papillae. The Fu were scattered among the Fi. Many Fo were observed on the posterolateral regions of the tongue. There were 2 Va separating the anterior 2/3 from the posterior 1/3 of the tongue. The rudiments of Fu, Fo and Va were visible earlier than those of the Fi.