Abstract

The ultrathin structure of carnivorous flagellate Metromonas grandis Larsen et Patterson has been investigated. The predator captures the whole cell of the prey (bodonids or chrysomonads). Cytostome as a cell pocket has not been found. The cell, besides the flagella and small parts of the folds, is surrounded by a fibrous layer 0.05–0.12 µm in thickness which consists of thick and thin bent shafts. The plasmalemma is beneath this layer. Two unequal flagella come out of a small pocket. The long flagellum bears multiple, very thin mastigonemes (hairs) 0.8–1.0 µm in length; the short flagellum is reduced and is covered by rare mastigonemes. The transversal plate is raised above the cell surface, surrounded by osmiophilic muff. Helix is absent. The root system is simplified and consists of two microtubular bands which originated near the kinetosome of the long flagellum. The kinetosomes lie parallel to each other and are interconnected with at least one fibrous bridge. Cylindrical extrusomes (trichocysts) 1.0–1.4 µm in length and 0.12–0.08 µm in diameter have been found in the cytoplasm. Trichocysts are divided by a diaphragm and contain a wheel-shaped structure with 13 spokes visible in cross sections. Contractile vacuole is absent. The resemblance of Metromonas grandis to M. simplex (Griessmann, 1913) Larsen et Patterson, 1990, Metopion fluens Larsen et Patterson, 1990 cryomonadids, and other predatory flagellates is discussed.

中文翻译：

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捕食性鞭毛Metromonas grandis Larsen et Patterson（Cercozoa）的细胞结构

摘要

食肉鞭毛大单胞菌的超薄结构Larsen et Patterson已被调查。捕食者会捕获猎物的整个细胞（bodonids或chrysomonads）。尚未找到细胞腔作为细胞袋。除鞭毛和褶皱的一小部分外，该细胞还被厚度为0.05-0.12 µm的纤维层围绕，该纤维层由粗细的弯曲杆组成。血浆问题在这一层之下。两个不等鞭毛从一个小口袋里出来。鞭毛长，具多个很薄的乳房状鞭毛（毛），长0.8-1.0 µm。短鞭毛被减少，并被罕见的马鞭草覆盖。横向板在细胞表面上方升高，并被同渗性套筒包围。螺旋不存在。根系经过简化，由两个微管带组成，它们起源于长鞭毛的动体附近。动体彼此平行，并与至少一个纤维桥相互连接。在细胞质中发现长度为1.0–1.4 µm，直径为0.12–0.08 µm的圆柱形挤出物（毛囊）。毛囊被膜片分开，并包含一个轮状结构，在横截面中可见13个辐条。没有收缩液泡。相似讨论了Metromonas grandis至M. simplex（Griessmann，1913）Larsen等，1990，Metopion fluens Larsen等，1990，冷冻单鞭毛虫，以及其他掠食性鞭毛虫。