Aim of the work: The present investigation aims to compare between the tongue, oesophagus and stomach of two birds in Egypt having different food habits.
Materials and methods: The animals under investigation are Whimbrel (Numenius phaeopus) and domestic duck (Anas platyrhnchos). These birds were caught from Abou-Rawash Constituency and Nile Delta in Egypt. The birds were dissected the tongue, oesophagus and stomach were fixed and stained for the microscopic comparative study.
Results: Histological results of this study found that the tongue of each bird (Whimbrel and domestic duck) is composed of three layers; mucosa, submucosa and muscularis. No lingual papillae are observed. The mucosal layer consists of stratified squamous epithelium. This layer in Numenius phaeopus is thicker than in Anas platyrhnchos. The submucosa is constructed from connective tissue. The muscularis is represented by bundles of muscle fibers extending in different directions. The lingual glands of Anas platyrhnchos are of compound alveolar type and have neutral mucopolysacchride content.
The muscularis of the oesophagus consists is consisting of outer circular and inner longitudinal muscle fibers. This layer is thick and well represented in Anas platyrhnchos than in Numenius phaeopus. The mucosal folds have stratified squamous epithelial cells. Oesophageal tubulo alveolar glands have acid mucopolysacchride content in Numenius phaeopus and neutral mucopolysacchride content in Anas platyrhnchos. The stomach in each bird (Whimbrel and domestic duck) is differentiated into glandular and muscular portions. The gastric glands of the glandular portion are differentiated into deep and superficial gastric glands. The muscularis of the muscular portion in the investigated birds is composed of circular and longitudinal muscle fibers. This layer in Anas platyrhnchos is thicker than in Numenius phaeopus. The mucosal layer in Anas platyrhnchos has thick tough keratin-like layer (cutica gastrica). The mucosal glands in the investigated birds have acid and neutral mucopolysacchride content.
The histological and histochemical results showed differences in the tongue, oesophagus and stomach between the investigated birds.