Microstructure of the tongue surface and lingual glands of the Sulawesi bear cuscus, Ailurops ursinus (Marsupialia: Phalangeridae)—A light and scanning electron microscopic study

Abstract

AbstractThis study aimed to evaluate the microstructure of the surface of the tongue and lingual glands of the vulnerable native Sulawesi bear Ailurops ursinus. The study was carried out on five tongues collected from four adult animals and one young animal. There was variation in the shape of the filiform papillae. Few conical papillae were observed on the caudo‐lateral surface of the tongue. The gustatory papillae included fungiform papillae on the entire lingual surface and three vallate papillae, with the largest papilla located centrally. The foliate papillae were present on all the studied tongues and consisted of parallel folia on the right and left caudo‐lateral side of the tongue, which were divided into five to eight sulci. Numerous openings of the lingual glands were present on surface of the root of the tongue. Histochemical studies of the cells of the lingual glands showed the differences between young and adult animals. Thus, the composition of the secretion of these glands depends on age of animals. An aggregation of lymphatic cells was observed beneath the surface of the root epithelium. Keel (enlargement of mucosa) was present on the ventral surface of the tongue medially and was composed of the connective tissue and epithelium.