Oesophageal and Gastric Morphology of the African Rope Squirrel Funisciurus anerythrus (Thomas, 1890)

Abstract

Aim: The aim of this study is to evaluate the gross, histological and histochemical features of the oesophagus and stomach of the African rope squirrel (Funisciurus anerythrus) were studied. Study Design: Experimental morphological study was carried out. Methodology: Gross dissection, routine histological technique and histochemistry using PAS and AB stains were conducted. Results: Grossly the oesophagus was a simple musculo-membranous short tube weighing 0.17±0.02 g and measured 8.5±0.1 cm in length and the stomach was visibly uncompartmentalized, it weighed 4.98±0.05 g and measured 4.32±0.3 cm in length. Histologically, the oesophagus showed a non-keratinized stratified squamous epithelium with longitudinal folds in the cervical part. The laminae muscularis mucosa was prominent with a thick smooth muscle layer in the thoracic part. Submucosal glands were absent. The muscularis externa were typical consisting of inner circular and outer longitudinal smooth muscle layers as in many rodents. The internal lining mucous cells were PAS- positive and AB- negative. The gastric mucosa exhibited typical gastric pits, throughout the three regions of the stomach (cardia, fundus, and pylorus) which lead to gastric glands. Well developed gastric glands were more abundant in the fundic part than in other regions and these glands showed mucoid cells lining the upper neck regions and distinct chief and parietal cells. The surface mucosal lining was PAS-positive and weakly AB –positive. The pyloric glands were weakly PAS-positive and strongly AB-negative. Conclusions: These findings indicated similarities to most omnivorous rodent species.