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

Abstract

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.

Morphological Comparison of the Filiform Papillae of New Zealand White Rabbits (Oryctolagus cuniculus) as Domestic Mammals and Egyptian Fruit Bat (Rousettus aegyptiacus) as Wild Mammals Using Scanning Electron Microscopic Specimens

“…As in the previous published data, the lingual papillae were species-specific, in which differing in their number among mammalian species, these differences may depend on dissimilarities in diet, feeding habits and handling of food in mouth (Emura et al, 2002b;Abumandour & El-Bakary), the previous data clear in; our study in Egyptian fruit bat, this confirmed by presence of four types of lingual papillae; two mechanical and two gustatory as noted in; bats (Selim et al, 2008;Abumandour & El-Bakary;Abayomi et al, 2009), moreover other mammals have four lingual papillae; as in our study in New Zealand white rabbits; one mechanical (filiform) and three gustatory (fungiform, foliate and circumvallate) as noted in; rats (Nasr et al, 2012), bank vole (Jackowiak & Godynicki, 2005), dog and fox (Emura et al, 2006). However, three types of lingual papillae; one mechanical (filiform) and two gustatory (fungiform and circumvallate) as noted in; bats (Pastor et al, 1993;Emura et al, 2001b;Park & Lee, 2009;Masuko et al, 2007), however, there were two types only of papillae (filiform and fungiform) in hematophagous bats (Masuko et al).…”

Palatal and lingual adaptations for frugivory and nectarivory in the Wahlberg’s epauletted fruit bat (Epomophorus wahlbergi)

“…In addition to capturing and manipulating foods, which are functions of the lingual papillae, the fungiform and circumvallate papillae facilitate taste of food (Kilinc et al 2010). Abayomi et al (2009) stated that the conical and crownlike structure of papillae observed in fruit bats suggest their function in food retention when flying. The papillae projections may be for gripping on food and scraping on fruits when feeding.…”

“…The papillae projections may be for gripping on food and scraping on fruits when feeding. The high abundance and increase in surface area of these enlarged papillae are most likely to assist in oral absorption (Abayomi et al 2009) and efficient transport of food, particularly a liquid diet, toward the pharynx and consequently increasing uptake.…”

Effect of irinotecan on the tongue mucosa of juvenile male albino rat at adulthood

“…There are four types of papillae identified on the mammalian tongue; circumvallate, fungiform and foliate papillae with taste buds, and filiform papillae without taste buds . The anterior region of Wistar albino rat's tongue dorsum contains two types of papillae: filiform and fungiform papillae, while few circumvallate papillae are seen in the posterior region of the tongue; (Karakoç et al.,). The number of circumvallate papillae varies from none to fourteen among the different species of mammals, and the Wistar albino rat is characterized by the presence of a solitary circumvallate papilla .…”