Comparative Morphohistological Study of Nasal Salt Gland in Three Water Birds Coot Birds (Gallinula silvestris), Domestic Geese (Anser anser domesticus), and Domestic Ducks (Anas platyrhynchus)

Background: The study's objective is to ascertain the comparative morphohistological features of salt gland of three species of birds, coot bird, duck and goose. Eighteen adult, healthy birds of each of the following sexes species (six birds for each species). Result: The frontal bone's supraorbital depression contains well-developed bilateral salt glands that are located beneath the skin in both species. The gland was ranged in color from pinkish white to reddish brown. in duck and goose were crescent in shaped, it was irregular or amebea –shaped, in the coot bird. Histological salt gland was covered by a thin capsule of connective tissue and comprise a large number of rows of concentric polygonal lobes divided by heavily vascularized interlobular connective tissue. Every lobe is composed of branching secretory tubules that are enmeshed with connective tissue that is rich in blood capillaries and lined with a single layer of cuboidal cells oriented radially from a central canal. Every lobe's duct system empties into the central canal, which empties into a primary duct that travels to the nasal cavity's anterior region. Conclusion: This study indicated that the three species of avian salt gland had distinctive histological structures, which helped to understand the impact of each species' habits and actions on this gland's development.