A Comparative Histological Study of the Tongue of Rat (Rattus Norvegicus), Bat (Eidolon Helvum) and Pangolin (Manis Tricuspis)

This study assessed the micro anatomical differences in the tongue of rat, bat and pangolin with a view to establishing the functional anatomical differences of these mammalian tongues on their dietary pattern. Ten rats, ten bats and ten pangolins were used for this study. The animals were sacrificed and the tongue excised and processed for light microscopical study adopting the following stains: Haematoxylin Eosin, Verhoeff Gieson and Masson trichrome. The results showed non papillation of the keratinized stratified epithelium of pangolin tongue unlike the papillation seen in the tongue of the rat and bat. While the filiform papillation seen in the rat was bristle like, the filiform papillae in the bat were crown-like. There was also an unusual dense collagenous ring in the proximal portion of the pangolin tongue which was absent in other mammals. There were taste buds along the lateral walls of the vallate papillae in the distal portion of the tongue of rats and bats but none was found in the pangolins. In conclusion, the morphology of the tongues of these mammals showed a relationship between their feeding pattern and the adaptive changes in the microanatomy of their tongue.