Histomorphometric and histochemical characteristics of the oesophagus of the greater mouse-eared Bat, Myotis myotis (Borkhausen, 1797).

The aim of this study was to examine the histomorphometric and histochemical structure of oesophagus of the wild-caught greater mouse-eared bat M. myotis. For this purpose, 10 specimens of oesophagus were collected and processed. The oesophagus wall of M. myotis is composed of four layers: tunica mucosa, tunica submucosa, tunica muscularis and tunica adventitia. The mucosa is covered by a non-keratinized stratified squamous epithelium. There were no glands in the wall of the oesophagus. Tunica muscularis is composed of two muscle layers: internal circular muscular layer and an external longitudinal muscular layer. Histochemical studies revealed that the oesophagus was AB/PAS and PAS positive indicating the presence of acidic and neutral mucosubstances. AB-PAS staining shows that glycoproteins were predominant in the all examined layers of the oesophagus. Because of the absence of oesophageal glands in M. myotis, positive reaction with AB-PAS staining may be due to secretion of salivary glands. Absence of oesophageal glands reflects the functional adaptation as high food passage rate for the insectivorous feeding habits of animals.