Comparative gross and scanning electron microscopical study of the oropharyngeal roof of young and adult domestic pigeons (Columba livia domestica).

The present study aims to compare the morphology of the oropharyngeal roof of young and adult domestic pigeon (Columba livia domestica) by gross observation, morphometric measurements, and scanning electron microscopy (SEM). The oropharyngeal roof was divided into the palate and pharyngeal roof. The palate was narrow triangular in shape and concave along its length. It could be divided into a rostral part contained three longitudinal palatine ridges and a caudal part contained the choanal slit. The choanal slit consisted of narrow rostral and wide caudal parts. The edges of the narrow part were encircled by small caudomedially directed papillae. On the contrary, the edges of the wide part of slit were free from papillae. By SEM, the palatal mucosa in young pigeon showed primordia of small papillae which increased in number and size forming a longitudinal row of papillae parallel to the edges of the rostral narrow part of slit in adult pigeon. The surface of the pharyngeal roof appeared smooth in young pigeon, while in adult pigeon, it showed dome-shaped elevations. The infundibular cleft had smooth edges. The caudal part of the pharyngeal roof formed an elevated transverse mucosal fold on which a transverse row of conical-shaped papillae was present. In conclusion, our results documented the presence of some differences between the oropharyngeal roof of young and adult pigeon, which suggest a high degree of functional adaptation in adult pigeon to their diet compared to young pigeon. Such adaptations might increase the efficiency of food prehension in adult pigeon. The present study compared the morphology of the oropharyngeal roof of young and adult domestic pigeon by gross observation, morphometry, and scanning electron microscopy. The morphometrical data showed higher values in adult pigeon compared to young pigeon. The palatal mucosa and the pharyngeal roof of adult pigeon showed papillae and elevations that were not present in young pigeon. Our results suggest a high degree of functional adaptation in adult pigeon to their diet compared to young pigeon. Such adaptations might increase the efficiency of food prehension in adult pigeon.
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