if you have green algae in your sample and you cultivate a specimen in
a mikro aquarium, you often find these footprints of new oedogonium filament colony
under the cover glass.
Objective 40x, DIC, flash, Pentax DSLR
Thanks,
Gerd
Gerd... I once floated a coverslip for a few days on a "rich" sample and found many of these. They are quite graphic to see, and now I know their name! Thanks.