Histomorphological Study of Tongue in Moorhen (Gallinulla chloropus)

Aims: The present investigation was carried out to offer fundamental information on themorphological and histological structure of the tongue in moorhens (Gallinulachloropus). For the current investigation to be carried out, seven moorhens werepurchased from the Baghdad, Iraq, commercial market. The samples(tongue) were thencarefully fixed in 10% neutral buffered formalin. The specimens were washed with tabwater then dehydrated with serial dilution of alcohol and cleared with xylene and thenembedded in paraffin wax. Following a five micrometer-thick sectioning, the slides werestained with hematoxylin and eosin. according to the gross findings our results showedthat the tongue was situated on the floor of the oropharyngeal cavity. A row of caudallypointed papillae arranged transversely known as lingual papillae separated the tongue'srostral and caudal regions. There was a laryngeal cleft beyond it, with one pharyngealpapillae row positioned caudally in a heart shape. There were a distinct keratinized bandson the dorsal surface of the tongue apex, the lingual mucosa's histology revealedstratified squamous epithelium with varying degrees of keratinization. Many mucosalglands were seen in the caudal part of the tongue; the secretions emptied into the ducts,this led to the tongue's dorsal surface opening. Whereas the papillae might act primarilyas physical barriers to the reflexive backward movement of food that has passed overthem, the glandular secretions may facilitate swallowing by lubricating the caudal regionof the oropharyngeal cavity in addition to the proximal part of the esophagus. The studyconcluded that the morphological features of the moorhen's tongue are likely adaptationsadequate to its unique feeding habits and methods of gathering food. These adaptationsmake the moorhen an excellent forager in ponds, marshes, and other wetlandenvironments, that has evolved a special beak and tongue to survive in its aquaticenvironments. Small aquatic invertebrates and plant matter can be filtered and retainedfrom the water by its tongue by means of papillae, which are hair-like projectionspointing backward. Because of these adaptations, moorhens are great foragers in ponds,marshes, and other types of wetland habitats.