Morphology and microstructure of the tongue of the lesser bamboo rat (Cannomys badius)

AbstractThe first detailed morphological description of the tongue and lingual papillae of the lesser bamboo rat, a fossorial rodent distributed in Indochina, is presented. Twelve tongues were examined by light, stereo‐ and scanning electron microscopy. The elongated tongue possessed an intermolar prominence and terminated in a rounded apex with a median sulcus. The dorsal surface of the tongue bore three types of papillae: filiform, fungiform and vallate, the first two of which were also observed on the ventral lingual surface. The filiform papillae varied in form and arrangement depending on the tongue region, although the majority of them were multifurcate, fork‐like papillae. The fungiform papillae were randomly scattered among the filiform papillae, with the highest density and number of taste pores (up to 12) at the ventral lingual apex. On the posterior tongue, two oval vallate papillae with numerous taste buds on their lateral epithelium were surrounded by a circumferential trench into which the serous von Ebner's glands’ ducts opened. The mucosal surface of the lingual radix was uneven without papillae, but contained mucous openings of Weber's glands. The tongue and lingual papillae of the lesser bamboo rat are similar to those of the large bamboo rat and show structural adaptations to the diet and food manipulation.