Histomorphological study on the tongue of the duck in the Caribbean with relation to feeding habit

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.

Gross Anatomical Features of Tongue of Khaki Campbell Duck (Anas platyrhynchos domesticus) At Different Postnatal Ages

The present study aims to investigate the gross morphological structure of the tongue of the khaki Campbell duck at different postnatal ages. The ducks were from four age groups (A total of 25 ducks): day one (1), one (1) month, two (2) months, three (3) months, and four (4) months, having five ducks in each group. The tongues were collected immediately after the ethical killing of the birds for gross anatomical observations. The tongue of the Khaki Campbell duck was located on the floor of the oropharynx. In all examined ages, the tongue did not extend to the total limits of the lower beak. The elongated shaped tongue was divided into three parts, i.e., apex, body, and root. The spatula-shaped apex of the tongue was smooth dorsally and devoid of lingual papillae. On the ventral surface of the apex, there was a flat, triangular, white plate of the lingual nail. The dorsal surface of the body of the tongue was divided into two symmetrical parts by a median groove, which became more prominent at the advancement of age. Large and small conical papillae were found symmetrically along both body edges. The root of the tongue was the smallest part which was located adjacent to the laryngeal prominence. Papillae were found on both sides of the root. A fold of membrane, the frenulum linguae present on the ventral aspect of the body. The length and width of the tongue increased with the advancement of age. The present study revealed the gross anatomical structure of the tongue of the Khaki Campbell duck at different postnatal ages and helped to compare the findings with other avian species.

Biological Aspects of the Tongue and Oropharyngeal Cavity of the Eurasian Collared Dove (Streptopelia decaocto, Columbiformes, Columbidae): Anatomical, Histochemical, and Ultrastructure Study

We characterized the morphological and anatomical adaptations of the lingual microstructures of the Eurasian collared dove and discussed their implications for its dietary niche. We analyzed tongues of nine S. decaocto using histological, histochemical, stereomicroscopic, and scanning electron microscopic techniques. Our findings showed that the tongue is relatively short with a tapered apex that carries a terminal lingual nail. However, the lingual body has median scales and is bordered laterally by filiform papillae. Further, the tongue body bears a distinctive papillary crest. The tongue root is nonpapillate and infiltered with orifices of the posterior salivary glands. The bulky laryngeal mound has a circular glottic fissure, carrying a single row of papillae at the rear edge. Concurrently, our histological and histochemical findings demonstrate that the tongue has taste buds, anterior and posterior salivary glands, along with an elongated entoglossum that extends from lingual apex to root. Besides, ovoid and globular mucous glands displayed intense alcianophilic reactions. More substantially, the palate is made up of three palatine ridges with a caudal choanal cleft that was bounded by two rows of palatine papillae. Our data indicate multiple and novel structural variations for the lingual and palatal sculptures coopted for their feeding style.