Although Limnostrombidium viride is a planktonic ciliate, I regularly find it even in sites that are not actually classic pelagic waters. However, the specimens are often found in or around floating plants. In samples the specimen then collect at the surface. Limnostrombidium viride can be easily identified by the green or yellow-green color. It is not caused by symbiotic algae, as in many other ciliates, but by their chloroplasts. That is, the phagocytosed algae are digested except for the chloroplasts, which remain fully functional and are then transported to the cell surface. By these “stolen” chloroplasts (s. fig. 3) Limnostrombidium viride can also be distinguished from the similar species Limnostrombidium pelagica, which does not possess these chloroplasts. In addition, Limnostrombidium viride has some other interesting features. For example, the posterior part of the body is covered by a thin sheath of colorless polygonal plates, which are difficult to detect in the unsquashed specimen (s. figs. 5 and 6). In addition, a tubular organelle is present in the posterior half of the body, which is called the “neoformation organelle” (s. fig. 3). It is thought to serve osmoregulation. This has been concluded because in many specimens no contractile vacuole is detectable.