A focus on the gross morphological and ultrastructural characteristics of the oesophagus and stomach of Eurasian common moorhen (Gallinula chloropus chloropus, Linnaeus 1758)

Abstract

The present work was the first attempt to examine the oesophagus and stomach of the Eurasian common moorhen grossly and by SEM. The oesophagus was composed of long cervical and short thoracic parts. The longitudinal folds of the cervical part were narrower than that of the thoracic part, while the depressions between these folds were shallower and wider in the cervical part. On the epithelial surface of the oesophagus, micropapillae were present and they were numerous and smaller at the level of the cervical part. The openings of the oesophageal glands were circular at the level of the cervical part and oval to elliptical at the thoracic part. The crop was absent. The proventriculus was fusiform in shape; its mucosa was arranged in several, concentrically arranged mucosal folds connected with each other by transverse folds. The proventriculus glands were oval and opened by raised papillae on the epithelial surface. The gizzard was oval; its mucosa was lined by a horizontal layer of cuticle appeared like the fish scales, while the vertical part of the cuticle appeared as thin rods. The folds of the oesophagus are functioning for the expansion for the passage of the food particles. The tunica musculosa of the gizzard was thick to help in grinding of the food particles.