COMPARATIVE HISTOLOGICAL STUDY OFESOPHAGUS AND LIVER IN SOME AQUATIC BIRDS

The present work aims to investigate the differences in the structure of liver and esophagus in five species of birds in Egypt having the same food habits.The birds under investigation are: water rail, spotted crake, little crake, common coot and common moorhen. Five birds were obtained from local hunters in Damietta, Egypt all of these birds are belonging to the same family (Rallidae)and all of them are omnivorous, but we found some difference after microscopical examination of liver and esophagus. The birds were dissected, esophagus and liver were fixed and stained for microscopic comparative study.The results revealed that there are some histological differences after microscopical examination to liver and esophagus in five species.In esophagus: Mucous glands are bigger in little crake than that in Rallus aquaticus,muscularis mucosa layer is thicker in Rallus aquaticus and common coot than that in Gallinula chloropus, inner circular in spotted crake is thinner that in Gallinula chloropus, and most thick in common coot. In Liver: Hepatocytes in common coot are polygonal in shape, have rounded nucleusand there are some sinusoids between hepatocords in liver and presence of secondary bronchial cavity in Gallinula chloropus and Rallus aquaticus.