Oliveira Radan Elvis Matias de, Attademo Fernanda Loffler Niemeyer, Sousa Ana Caroline Freitas Caetano de, Magalhães Marcela Dos Santos, Oliveira Rysónely Maclay de, de Moura Carlos Eduardo Bezerra, Silva Alexandre Rodrigues, Pereira Alexsandra Fernandes, Fragoso Ana Bernadete Lima, Silva Flávio José de Lima, Oliveira Moacir Franco de
Programa de Pós-Graduação em Ciência Animal (PPGCA), Universidade Federal Rural do Semi-Árido (UFERSA), Mossoró, Rio Grande do Norte, Brazil.
Centro de Estudos e Monitoramento Ambiental (CEMAM), Areia Branca, Rio Grande do Norte, Brazil.
Anat Rec (Hoboken). 2023 Feb;306(2):343-353. doi: 10.1002/ar.25061. Epub 2022 Aug 30.
Morphological studies of the oropharyngeal cavity of chelonians have become an interesting tool in the understanding of evolutionary processes associated with feeding habits in aquatic animals and the transition from aquatic to terrestrial forms. In this context, the aim of the present study was to describe the oropharyngeal cavity floor morphology of hawksbill sea turtle (Eretmochelys imbricata) hatchlings. Ten dead hatchlings of undefined sex were obtained from nests hatched on the coast of the state of Rio Grande do Norte, Brazil. The heads of each specimen were fixed, dissected, and analyzed at the macroscopic and microscopic levels. The oropharyngeal cavity floor of the hawksbill sea turtle hatchlings is formed by the tongue, pharynx, floor muscles, and hyolingual skeleton, delimited in the rostral and lateral directions by a keratinized beak, called the rhamphotheca, and in the caudal region at the limit between the pharynx and the esophagus. The tongue muscles and the muscles that support the floor of the oral cavity comprise the following: m. hypoglossohyoideus, m. hypoglossoglossus, m. hyoglossus, m. genioglossus, m. constrictor laryngis, m. geniohyoideus pars lateralis, and m. intermandibularis. The oropharyngeal cavity floor mucosa is formed by keratinized stratified squamous epithelium and the lamina propria is formed by loose connective tissue. The floor mucosa is devoid of taste buds. We believe that the basic oropharyngeal cavity floor characteristics in hawksbill sea turtle hatchlings may comprise indications that these animals are plesiomorphic and that semiaquatic and terrestrial turtles may have undergone adaptations to feed out of water.
龟类口咽腔的形态学研究已成为理解与水生动物摄食习性以及从水生形态向陆生形态转变相关的进化过程的一个有趣工具。在此背景下，本研究的目的是描述蠵龟（Eretmochelys imbricata）幼龟口咽腔底部的形态。从巴西北里奥格兰德州海岸孵化的巢穴中获取了10只性别未明的死亡幼龟。对每个标本的头部进行固定、解剖，并在宏观和微观层面进行分析。蠵龟幼龟的口咽腔底部由舌头、咽部、底部肌肉和舌骨骨骼组成，在头侧和外侧由角质化的喙（称为嘴鞘）界定，在尾侧则位于咽部和食管之间的界限处。舌肌和支撑口腔底部的肌肉包括：舌下舌骨肌、舌下肌、舌骨舌肌、颏舌肌、喉括约肌、颏舌骨肌外侧部和下颌间肌。口咽腔底部黏膜由角质化的复层鳞状上皮形成，固有层由疏松结缔组织形成。底部黏膜没有味蕾。我们认为，蠵龟幼龟口咽腔底部的基本特征可能表明这些动物是原始的，并且半水生和陆生龟类可能已经经历了适应在水外进食的过程。
