Posthatching developmental studies on the tongue and laryngeal entrance of the common quail (Coturnix coturnix, Linnaeus, 1758) in different five age-stages

Anatomical and Surface Electron Microscopic Investigation of the Tongue and Laryngeal Prominence in the Red-Eyed Turtle Dove (Streptopelia semitorquata, Rüppel 1837)

This study investigated the morphology of tongue and laryngeal structures in red-eyed dove and related it to feeding habits. Samples were examined using gross anatomy, scanning electron microscopy (SEM), and histological techniques. The tongue conformed to the shape of the lower beak, and the apex with a pointed tip, body, and root were distinguished. A median grove was apparent, and a papillary crest with pointed triangular papillae separated the body from the root. The length of the tongue, its width (body), and the percentage of the length of the lower jaw occupied by the tongue were, on average, 12.5 mm, 2.3 mm, and 57.3%, respectively. SEM showed highly desquamated dorsal epithelium with pointed papillae-like projections. The papillary crest presented pointed papillae of about 20-22. Salivary openings were apparent in the root, surrounded by mucosal folds and blunt papillae. Laryngeal prominence was irregularly triangular shaped and elevated. The rim of the glottis showed glandular pinpointed marks. Typical cornified multilayered mucosal epithelium was present in the apex and decreased caudally. Hyaline entoglossal cartilage and adjoining connective tissue were present in the body and apex. Numerous tubuloalveolar glands were seen in the body and root. The rim of the glottis showed mucous intraepithelial glands. The rostral and caudal lingual glands indicated positive reaction to neutral and acidic mucins. This study demonstrated a morphofunctional relationship of the tongue of a red-eyed dove to its diet.

Tongue of the Egyptian Endemic Bridled Skink (Heremites vittatus; Olivier, 1804): Gross, Electron Microscopy, Histochemistry, and Immunohistochemical Analysis

The present study used light and scanning electron microscopy to describe the integrative morphological description of the tongue and laryngeal mound of Heremites vittatus, an endemic lizard of Saharan Africa. Additionally, ultrastructure, histology, histochemistry, and immunohistochemical approaches were used to characterize the lingual apparatus adaptations. In the present study, Heremites vittatus consisted of a complex lingual papillary system in which the ventral apical surface of the foretongue comprised conical papillae. The dorsal surface consisted of different filiform papillary (papillae filiformes) types: the anterior section had two types (bifid and pointed), and the posterior section had four types (triangular, trifid, quadrifid, and pentafid) papillae. The dorsal midtongue surface exhibits scale-like, serrated filiform papillae with anterior gland openings. The hindtongue consisted of two overlapping filiform papillae: scale-like, board-serrated papillae on the median portion and finger-like papillae on the wings. The dorsal surface of the laryngeal mound had 18 longitudinal folds with glandular openings. Histologically, the foretongue was covered by a slightly keratinized layer that was absent in the mid- and hindtongue. The lingual glands were absent from the foretongue but present in the interpapillary space in the mid- and hindtongues. We observed a few rounded taste buds in the conical papilla epithelium. Histochemical analysis revealed strong glandular Alcian Blue (AB)-positive and Periodic Acid-Schiff (PAS)-positive reactions. Immunohistochemistry showed strong cytokeratin immunopositivity in all parts of the tongue. In conclusion, the obtained data about the lingual characterizations have been consistent with the active foraging behavior of the species and its environmental conditions.

Histo-morphological Characterization of the Tongue and Oropharyngeal Cavity of the Shining Sunbird (Cinnyris habessinicus)

Sunbirds, as specialized nectarivores, have developed multiple lingual and oropharyngeal peculiarities imposed by this dietary specialization that particularly extract floral nectar. We have described the functional morphology of the tongues and palates of the shining sunbird, Cinnyris habessinicus, using gross anatomical, histological, and scanning electron microscopic methods. The tongue was bifurcated with fringed lamella and extended posteriorly, forming a broad trough at the lingual body and terminating in two fleshy, alae linguae. The lingual apex and body are nonpapillate and nonglandular, and its root had a muscular pad followed by a conspicuous laryngeal mound bordered by three prominent rows of conical papillae. The lingual root had clusters of mucoid glands with rich acidic mucins, and the laryngeal region had complex papillary distribution at the back margins. Both the lingual body and root had well-developed skeletal elements, musculature, and connective tissues. Furthermore, the palate was membranous and made up of four main ridges with a central choanal slit guarded by choanal papillae. Overall, the presented results showed structural and anatomical features that are the results of the nectarivory dietary niche.

Ultrastructural adaptation of the oropharyngeal cavity of the Eurasian common moorhen (Gallinula chloropus chloropus): Specific adaptive dietary implications

The present investigation represents the first morphological description of the oropharyngeal cavity of Eurasian common moorhen. Nine oropharyngeal cavities were examined grossly and by stereomicroscope and scanning electron microscopic (SEM) observations. The tongue had a rounded apex with multiple acicular processes on its rostral and lateral borders. The dorsal lingual surface of the apex and body had a median sulcus. The papillary crest carried four caudally directed triangular conical papillae on its median part and four triangular conical papillae on each lateral part. The filiform papillary system; small papillae on apex and long papillae on the rostral part of the body while broad papillae on the caudal part of the body. The lingual root had a special appearance by presence of three areas: mucosal fossa, two lateral ridges, and rhomboidal elevated central part. The caudal border of the mound carried heart-shaped pharyngeal papillae that possessed three papillary rows. The palate had a median palatine ridge rostrally that surrounded by two lateral palatine ridges. The choanae had two equal parts: rostral tapering and wide caudal. The rostral tapering choanal part was surrounded by two longitudinal rows of caudally directed conical papillae, one on each side. There was a single transverse row of conical papillae on each side of the caudal part of the rostral tapering choanal part. The caudal wide choanal part did not encircle by any papillae. Our conclusion exhibited unique structural and functional specifications of the oropharyngeal cavity with the tongue that evident with nutritional behavior.

Ultrastructural and histological descriptions of the oropharyngeal cavity of the rock pigeon Columba livia dakhlae with special refer to its adaptive dietary adaptations

The current investigation gave a full ultrastructural and histological description of the oropharyngeal cavity of the rock-pigeon Columba livia dakhlae. Our study carried on 10 heads of adult rock pigeons by gross, scanning, and light microscopic examination, in addition to the immunohistochemical analysis of the cytokeratin of the dorsal surface mucosa epithelium and the proliferating cell nuclear antigen expression (PCNA) immunoreactivity. The pointed apex of the elongated tongue covered rostrally and laterally with numerous caudally directed scales-like papillae. The dorsal surface of the apex and body was covered with numerous caudally directed scales-like filiform papillae. The U-shaped transverse papillary crest carried caudally directed pointed triangular conical papillae with two giant papillae. The elevated caudal area of the lingual body contains little numbers of the opening of the lingual gland. The laryngeal mound is divided into two symmetrical halves by rostral fissure and caudal laryngeal fissure into the right and left half. There were four palatine ridges: two lateral, middle, and median ridges. The choanal field bounded by the two lateral palatine ridges and containing the median choanae. The rostral part of the palatine cleft bounded laterally by a line of the small caudally directed conical papillae, while the caudal part was free from these papillae. There was a little number of taste buds in the palate. The high magnification of the rostral part of the beak is covered with directed rods-like projections. In conclusion, the obtained results described the adaptations of the tongue and its belonged structures with the feeding demand of the rock-pigeon.