The genital papillae of the fresh-water mite, Limnochares aquatica (L., 1758) were studied using TEM and SEM methods. The papillae are multiple organs spreading in large number over the ventral body surface. Each papilla is composed of the basal internal portion immersed into the body cavity and the external bowl-shaped portion placed among cuticular protuberances. A semi-spherical cap bearing minute pores covers the papillae bowl. An electron-lucent chamber is present between the cell apexes and the cuticle of the papillae cap. The latter is formed of the endo- and the exocuticle pierced by pores. The papillae are built of columnar cells with nuclear zone occupying the basal portion and the apical zone extending within the bowl and forming plications of the apical plasma membrane. Numerous electron-clear vesicles detach from both the basal and the lateral plasma membrane of papillae cells. The mitochondrial pool is quite moderate. The cells also contain numerous axial microtubules, glycogen particles, single residual bodies as well as minute apical vesicles supposedly releasing secretion into the lucent chamber. This secretion is accumulated underneath the cuticle of the cap and moving out through the pores to the outside. Following TEM organization, the papillae function in vesicular transportation of exceeding water and solutions across the organ from the organism to the external medium. The reverse active path of ions through the apical plasma membrane is also possible. In general, the papillae organization corresponds to chloride cells of aquatic insects taking part in ion–water balance but seems to be more primitive than analogous organs of other mites studied.

中文翻译：

---

淡水螨 Limnochares Aquatica (L., 1758) (Acariformes, Limnocharidae) 生殖乳头的超微结构

使用 TEM 和 SEM 方法研究了淡水螨 Limnochares Aquatica (L., 1758) 的生殖乳头。乳头是大量分布在腹侧体表的多个器官。每个乳头由浸入体腔的基部内部和位于角质突起之间的外部碗状部分组成。带有微小孔的半球形帽盖覆盖乳头碗。在细胞顶点和乳头帽的角质层之间存在一个电子透明室。后者由被孔刺穿的内表皮和外表皮形成。乳头由柱状细胞构成，核区占据基底部分，顶端区在碗内延伸并形成顶端质膜的褶皱。许多电子透明的囊泡从乳头细胞的基底膜和侧质膜上脱离。线粒体池相当温和。这些细胞还包含许多轴向微管、糖原颗粒、单个残留体以及微小的顶端小泡，据称可将分泌物释放到透明室中。这种分泌物积聚在帽子的角质层下方，并通过毛孔向外移动。继 TEM 组织后，乳头在从生物体到外部介质跨器官的过量水和溶液的囊泡运输中起作用。离子通过顶端质膜的反向活性路径也是可能的。一般来说，