Beisser C J, Weisgram J, Hilgers H, Splechtna H
Institute of Zoology, University of Vienna, Austria.
Anat Rec. 1998 Feb;250(2):127-35. doi: 10.1002/(SICI)1097-0185(199802)250:2<127::AID-AR1>3.0.CO;2-0.
Turtles are adapted to different environments, such as freshwater, marine, and terrestrial habitats. Examination of histological and ultrastructural features of the dorsal lingual epithelium of the red-eared turtle, Trachemys scripta elegans, and comparison of the results with those of other turtles should elucidate the relationship between the morphology of tongues as well as the fine structure of lingual epithelia and chelonian feeding mechanisms.
Light microscopical (LM) and scanning (SEM) and transmission (TEM) electron microscopical methods were used.
SEM revealed a distribution of lingual papillae all over the dorsal tongue surface. Single epithelial cells can be discerned, with short microvilli on their surface. LM studies show differences within the stratified epithelium between the lateral and the apical side of the papillae. In TEM, these differences become more obvious; while the basal and deep intermediate layer is similar in both sides of the papillae, mucus granules begin to form at the edge of the superficial intermediate layer at the lateral side. Cells containing fine secretory granules are visible there, too. On the other hand, at the apical side, only fine-granule-containing cells are visible.
This study indicates that the histology and ultrastructure of the lingual epithelium of Trachemys scripta elegans are similar to that of other turtles adapted to freshwater environments but differ from those of turtles living in marine or terrestrial habits. These differences can be explained in terms of the adaptation of turtles to their particular life circumstances.
龟类适应不同的环境，如淡水、海洋和陆地栖息地。对红耳龟（滑龟）舌背上皮的组织学和超微结构特征进行研究，并将结果与其他龟类进行比较，应能阐明龟类舌头形态以及舌上皮精细结构与摄食机制之间的关系。
采用光学显微镜（LM）、扫描电子显微镜（SEM）和透射电子显微镜（TEM）方法。
扫描电子显微镜显示舌乳头分布于整个舌背表面。可辨认出单个上皮细胞，其表面有短微绒毛。光学显微镜研究表明，乳头侧面和顶端的复层上皮存在差异。在透射电子显微镜下，这些差异更为明显；乳头两侧的基底和深层中间层相似，而在侧面，粘液颗粒开始在浅表中间层边缘形成。在那里也可见到含有细小分泌颗粒的细胞。另一方面，在顶端，仅可见到含有细小颗粒的细胞。
本研究表明，红耳龟舌上皮的组织学和超微结构与其他适应淡水环境的龟类相似，但与生活在海洋或陆地环境中的龟类不同。这些差异可以从龟类对其特定生活环境的适应角度来解释。
