Jason, thanks for the new calibration shots and thank for this thread. It's one of my faves.
Here's what I was looking at and wondering if I was seeing bacteria. The dark ovals are I believe Dinoflagellate cysts probably ~60 microns across give or take. The small moving guy is a small cell amphidinium about 15 microns or so.
The wiggling on the cyst looking thing is what I was intrigued by. seems appropriate size to be bacteria on the surface of the cyst (maybe).
https://youtu.be/Ne_XJbpXZXU