Department of Anatomy and Cell Biology, Faculty of Medicine, University of Cantabria, Santander, Spain.
Department of Veterinary Sciences, Polo Universitario dell'Annunziata, University of Messina, Messina, Italy.
J Morphol. 2020 Dec;281(12):1588-1597. doi: 10.1002/jmor.21271. Epub 2020 Oct 9.
We report here on the histological and structural characteristics of the gas bladder, the vertebral morphology, and the bladder-vertebra relationships of the butterfly fish, Pantodon buchholzi. The bladder opens at the boundary between the pharynx and the esophagus by a middle slit. A pneumatic duct is absent. The bladder shows a dorsolateral wall that adapts to the anfractuosities of the coelomic cavity and a ventral wall in contact with the abdominal organs. The vertebral bodies are formed by an hourglass shaped autocentrum, and by an arcocentrum reduced to several longitudinal ridges. The transverse processes adopt the structure of a cage whose walls are formed by bone trabeculae of variable size and distribution pattern. The dorsolateral wall of the bladder is a membrane that covers the kidney, adapts to the irregular shape of the vertebrae, and invades the transverse processes at several points before extending laterally. However, invasion of the vertebral bodies, the presence of a labyrinth, or the formation of respiratory parenchyma were not observed. The luminal surface of this wall is a thin respiratory barrier containing a single epithelial cell type. In addition, the wall contains numerous eosinophils that may be implicated in immune defense. The bladder ventral wall is a membrane rich in collagen, vessels, smooth muscle, and nerves that lacks a respiratory barrier. Its luminal surface contains ciliated and nonciliated cells. The two cell types appear implicated in surfactant production.
我们在此报告蝴蝶鱼（Pantodon buchholzi）的气囊组织学和结构特征、椎体形态以及气囊-椎体关系。气囊通过中间的裂缝开口于咽和食管之间。没有气动导管。气囊具有适应体腔陷凹的背外侧壁和与腹部器官接触的腹侧壁。椎体由沙漏形的中心体和几个纵向嵴组成的弧形中心体形成。横突采用笼状结构，其壁由大小和分布模式不同的骨小梁形成。气囊的背外侧壁是一层覆盖肾脏的膜，适应于椎体的不规则形状，并在横向过程中在几个点延伸到横向过程中。然而，没有观察到对椎体的侵犯、迷路的存在或呼吸实质的形成。该壁的腔面是一层含有单一上皮细胞类型的薄呼吸屏障。此外，该壁还含有许多嗜酸性粒细胞，可能参与免疫防御。气囊腹侧壁是一层富含胶原蛋白、血管、平滑肌和神经的膜，缺乏呼吸屏障。其腔面含有纤毛细胞和非纤毛细胞。这两种细胞类型似乎都参与表面活性剂的产生。
