My “Spirogyra” culture is really a Chlorella culture with a small Spirogyra problem. Other things in it: Lots of Rotifers, spiky things that might be Desmids (see below), but only the occasional Acanthocystis (aka heliozoans). Sure wish I knew if these Chlorella had come from Acanthocystis because I have a little bit of virus I could add to this and get an amplifcation. Maybe I will throw the dice and try that on Thursday.
Amazing that a cell can be so spiky and angular.