Rudzinska M A
J Cell Biol. 1965 Jun;25(3):459-77. doi: 10.1083/jcb.25.3.459.
The feeding apparatus of Suctoria consists of long, thin, stiff tubes called tentacles. When a swimming prey attaches to the tip of the tentacle a number of events follow in rapid succession. The tentacle broadens, a stream of tiny granules starts to move upward at its periphery to the tip, the prey becomes immobilized and shortly thereafter the cytoplasm of the still living prey begins to flow through the center of the tentacle to the body of the predator. An electron microscope study of the tentacle in Tokophrya infusionum, a protozoan of the subclass Suctoria, has disclosed a number of structural details which help to clarify some of the mechanisms involved in this unusual way of feeding. Each tentacle is composed of two concentric tubes. The lumen of the inner tube is surrounded by 49 tubular fibrils most probably of contractile nature. In the inner tube the cytoplasm of the prey is present during feeding, and in the outer tube are small dense bodies. It was found that the dense bodies originate in the cytoplasm of Tokophrya. They have an elongate, missile-like appearance, pointed at one end, rounded at the other, and are composed of several distinct segments. At the tip of the tentacle they penetrate the plasma membrane, with their pointed ends sticking out. It is assumed that the missile-like bodies play a major role in the feeding process. Their composite structure suggests that they might contain a number of enzymes which most probably are responsible for the various events preceding the actual food intake.
吸管虫类的摄食器官由称为触手的细长、坚硬的管子组成。当游动的猎物附着在触手尖端时，一系列事件会迅速相继发生。触手变宽，一股微小的颗粒流开始在其周边向上移动至尖端，猎物被固定住，此后不久，仍活着的猎物的细胞质开始通过触手中心流向捕食者的身体。对吸管虫亚纲原生动物点滴钟形虫触手的电子显微镜研究揭示了许多结构细节，这些细节有助于阐明这种独特摄食方式所涉及的一些机制。每条触手由两根同心管组成。内管的管腔被49根很可能可能可能具有收缩性质的管状纤维围绕。在摄食过程中，猎物的细胞质存在于内管中，外管中有小的致密体。研究发现，致密体起源于点滴钟形虫的细胞质。它们呈细长的导弹状，一端尖，另一端圆，由几个不同的部分组成。在触手尖端，它们穿透质膜，尖端伸出。据推测，导弹状物体在摄食过程中起主要作用。它们的复合结构表明，它们可能含有多种酶，这些酶很可能负责实际摄取食物之前的各种事件。
