Tongue structure in the long-eared hedgehog (Hemiechinus auritus): A scanning electron microscopic study.

The aim of this study was to investigate the dorsal surface of the long-eared hedgehog tongue using scanning electron microscopy. The tongue of the long-eared hedgehog is rectangular-shaped with an elongated body and a widened root and a marked deep median groove can be seen on its dorsal surface. A characteristic feature of the lingual root is presence of two huge laterally situated folds. These anatomical structures have never been described with regard to other small mammals studied so far. According to their anatomical appearances, the lingual papillae can be distinguished as filiform, conical, fungiform, circumvallate and foliate papillae. The filiform papillae covering the body of the tongue are longer and wider than those on its apex and have an apparent fork-like appearance. Fungiform papillae are evenly distributed on the dorsal surface of the apex and body of the tongue. The triangular area of the lingual root contains small caudally directed conical papillae with single processes. Foliate papillae are situated on both lateral surfaces of the lingual root medial to the huge lateral lingual folds as three large obliquely situated parallel folds. There are three circumvallate papillae, two of which are obliquely situated on both sides of the rostral part of the lingual root, while the third one is situated in the midline of the caudal part of the lingual root. The results show that the tongue structure of the long-eared hedgehog is more complex in comparison with other mammals which is related to its phylogeny and feeding habits.