In one of my moist-chamber-mounts there were some specimens of Paralieberkuehnia elegantula, attached to the cover slip. In this position they are nice to observe and to make photomicrographs.
One morning I saw two cells within a shell. I followed this process for some time. During one hour, nothing happened. The cells moved a little, but after some time the left cell showed a flagellum which was moving inside the shell. The arrows indicate the flagellum, visible as a double line.
The right cell, the mother cell, had its granulopodia stretched out through the narrow aperture. After an hour the left cell, the daughter cell, started to move slowly towards the aperture.
It lasted for about ten minutes before the daughter cell had reached the aperture and pressed itself through the narrow neck.
The arrow indicates the daughter cell, now becoming a swarmer or zoospore.
One minute later the zoospore left the shell. Two minutes later it had suddenly gone, I missed the moment it swam away when changing an objective!.
I found the swarmer after six minutes. A new shell has already been shaped. The arrows indicate the faint outline of the new shell. The new location was very close to the mother shell, but the swarmer had settled on the object slide.
The flagellum (arrow) was visible for at least half an hour.
Fifteen minutes after leaving the mother shell, the daughter cell had made a new shell and had already stretched her filopodia through the aperture to catch prey.