Beobachtung von Diatomeen




Amoebae


In a raw culture with diatoms of the genus Cymbella, bacteria quickly spread over the substrate. A short time later, amoebas with a typical size of 17 Ám (diameter including ectoplasm) could be observed, which quickly proliferated. The culture can be seen in the following video (150x time lapse) in phase contrast.






Below you can see the appearance of amoebae in a raw culture of Meridion circulare (60x time lapse).





Although it does not contribute anything to the topic of diatoms, a video (150x time lapse) is shown below in which numerous amoebas move over the bottom of the petri dish and eat bacteria.






They form a dense chain. This appears to be caused by the fact that the amoebas move more slowly in a region of high bacterial density and systematically move further in the direction in which they were successful. Chemotaxis could play a role. In the area behind the chain, which is almost free of bacteria, the amoebae move in a kind of random walk.





Thomas Harbich   https://diatoms.de/en/culturing/creating-cultures-and-care