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

Abstract

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.

Comparative morphological study of the oropharyngeal floor of squabs and adult domestic pigeons (Columba liviadomestica)

“…The length of the lower beak in pigeon was slightly shorter than that of the upper beak. Our result is in consistence with that of Mahdy (2020) who reported that the upper beak of pigeon is slightly longer and forms a hook‐like over the lower beak. Since pigeons are granivorous birds that feed mainly on seeds and grains (Biedermann, Garlick, & Blaisdell, 2012), the characteristic shape of both the upper and lower beaks help pigeon to pick and hold the seed and prevent its dropping (Trivedi & Soni, 2013).…”

“…The glottis lied opposite to the caudal part of the choanal slit in both squabs and adult pigeons. Similar finding was reported in pigeon, laughing dove, quail, turkey, duck, and goose (Madkour, 2018; Madkour, Abdalla, & Mohamed, 2019; Mahdy, 2020; Mohamed, 2004; Mohamed et al, 2018; Mohamed & Zayed, 2003; Sayed, Abdalla, Saleh, & Ahmed, 2017). In contrast, the wide part of the slit lied rostral to the glottic fissure in chicken (Mohamed & Zayed, 2003).…”

“…Recently, Abumandour and Kandyel (2020) demonstrated the age‐related changes in the tongue of rock pigeon by SEM and light microscopy. In addition, Mahdy (2020) reported the existence of some morphological differences between the oropharyngeal roof of squabs and adult domestic pigeon as shown grossly and by SEM. Such differences reflect higher effectiveness of food prehension in adult pigeons than in young pigeons.…”

Histomorphogenesis of the Pharyngeal roof in Muscovy Ducks (Cairina moschata)

“…Erdogan and Alan (2012) recorded that this length is 1.41 mm, 3.69 mm in the European magpie and Common raven, respectively. When viewed with SEM, the edges of the infundibular slit were smooth in all developmental stages as mentioned in laughing dove (Madkour, 2018) and pigeon (Mahdy, 2020) except few fine and caudally directed papillae were recognized at 60 days old. Hassouna (2002) in duck and Ali (2004) in ostrich reported that the surface epithelial cells at the infundibular slit appears covered with microvilli of variable length and density.…”

“…In house sparrow, the pharyngeal roof is demarcated from the esophagus by 18-20 caudomedially directed small-sized pointed papillae (Abumandour,2018). Moreover, Mahdy (2020) reported in pigeon that the pharyngoesophageal junction represents by elevated transverse mucosal fold bear a transverse row conical-shaped papilla with pointed apices. In contrast, Tadjalli et al (2008) reported that there is no transverse row of papillae at the junction with the esophagus in ostrich.…”