This week I did more plankton trails with my home-brewed software. It can be tricky to record the right video, as the bigger zooplankton like to swim into the frame and obliterate all the detail. But I got a few good ones.
A small cladoceran generating a large current:
Also saw a few things I’ve never found before, like some super cute bosmina (relative of daphnia) from Okoboji, and a hydra from a pond in a field nearby.
I later made cyanotypes on cloth of plants juxtaposed with the plankton trails. Later in the week I attended some lectures on algae by Kalina Manoylov. It was absolutely fascinating learning about dinoflagellates and diatoms. I do wish I went to more algae lectures, these creatures are so interesting (their feeding mechanisms, my god!).
On thursday I went with the algae and aquatic ecology classes to Silver Lake Fen, to collect some samples. I collected from the pools in the fen surface, as well as nearby silver lake. When I got back I quickly took them back to my microscope… it took a little searching but I found them: diatoms!
I’ve never found diatoms before. After attending Kalina’s lecture I knew what to look for. And it helped using higher magnification and brightfield.
Diatoms have a glass exterior (frustrule) covered in pores that is amazing when examined via scanning electron microscopy:
There were tons of diatoms in the sample from silver lake. Kalina helped me identify some.
As I understand it they move by secreting a mucus and sort of sliding on it.
Also found some amoeba tests (shells they construct, which did not appear to be inhabited), probably euglypha:
Lastly, I made another zooplankton kaleidoscope.