Anatomical and scanning electron microscopic characteristics of the tongue in the pampas deer (Cervidae: Ozotoceros bezoarticus, Linnaeus 1758)

Abstract

This study represents the first definitive anatomical description of the tongue and lingual papillae of the pampas deer and compares the different information on the morphology of the other ruminant species available in the literature. In this study, the tongues of four adult and one fetal deer were used. The tongue was elongated with an oval or rounded apex. The filiform papillae on the lingual apex were smaller than the ones on the dorsal and lateral surfaces of the lingual body. Two very thin secondary papillary projections were found to emerge from the bilateral sides of some filiform papillae. Spherical fungiform papillae were randomly distributed among filiform papillae on dorsal surface of the lingual body and ventral surface of the apex. More developed conical papillae were observed in the caudal half of the lingual torus, whereas the rostral half of the torus had smaller conical papillae. Each conical papilla included shallow longitudinal groove on its anterior surface and some conical papillae on the lingual torus had bifid sharp apices. On the caudal portion of the torus, we also observed a few fungiform papillae, which were larger than those located on the lingual body. There were no lenticular papillae on the lingual torus, and five to nine round or oval circumvallate papillae were situated on each caudolateral side of the lingual torus. Morphological features of the tongue in the pampas deer were more similar to wild ruminant species than they were to domestic species.