Abstract Histological and histochemical features of the oesophagogastric segment of the alimentary canal as well as ultrastructure of gastric gland cells of freshwater tubenose goby Proterorhinus semilunaris were examined. The studies revealed that despite the lack of anatomical distinction, the oesophagogastric segment is histologically divided into the oesophagus, oesogaster and stomach, which provides evidence for the functional compartmentation of this organ. The oesophagus was characterised by the presence of numerous goblet cells secreting mainly a mixture of neutral and acid mucopolysaccharides. In the stomach, the apical zone of the surface epithelial cells contained neutral mucopolysaccharides. Numerous proliferating cells were scattered throughout the surface epithelium. In the lamina propria of the stomach, a well-developed layer of gastric glands was observed. The glands were of the alveolar type and occupied nearly the entire length of the stomach except the pyloric region. The gastric gland cells were varied into light and dark; however, their ultrastructure was identical. All cells had numerous mitochondria and a well-developed tubulovesicular system typical for the oxynticopeptic cells, but pepsinogen granules were not present in the cytoplasm of these cells. These findings contribute new evidence to literature reports that not all gobiid fish are stomachless. Moreover, they suggest higher adaptation of the species to utilise protein-rich food compared to stomachless fish, and its ability to adjust the alimentary canal quickly to changing diet. How this may facilitate establishment of P. semilunaris in invaded environments remains an open question.

中文翻译：

---

组织学、组织化学和超微结构分析揭示了淡水管鼻虾虎鱼 Proterorhinus semilunaris Heckel，1837 年食管胃段的功能划分

摘要 研究了淡水虎斑虾虎鱼 Proterorhinus semilunaris 消化道食管胃段的组织学和组织化学特征以及胃腺细胞的超微结构。研究表明，尽管缺乏解剖学上的区别，食管胃段在组织学上分为食管、食管胃和胃，这为该器官的功能区室提供了证据。食道的特征是存在大量杯状细胞，主要分泌中性和酸性粘多糖的混合物。在胃中，表面上皮细胞的顶端区域含有中性粘多糖。许多增殖细胞散布在整个表面上皮细胞中。在胃的固有层中，观察到发育良好的胃腺层。这些腺体是肺泡型的，几乎占据了胃的整个长度，除了幽门区域。胃腺细胞有明暗变化；然而，它们的超微结构是相同的。所有细胞都具有许多线粒体和发育良好的管状囊泡系统，这是胃泌尿细胞的典型特征，但这些细胞的细胞质中不存在胃蛋白酶原颗粒。这些发现为文献报告提供了新的证据，即并非所有的戈壁鱼都是无胃的。此外，他们表明与无胃鱼相比，该物种对利用富含蛋白质的食物具有更高的适应性，并且能够快速调整消化道以适应不断变化的饮食。这将如何促进 P 的建立。