On a contractile stalk. Coiled into a helical shape when contracted, then would straighten.
Darkfield image. 20x objective.
Found attached to algae in backyard pond.
Sample taken from water collected on top of pondless Waterfall.
210 um long, 83 um wide at mid point
I took a short timelapse of the cellular contents shifting around at 5x speed. Maybe it's a rotifer egg of some kind?
https://youtube.com/shorts/dSxbX9smukE?feature=share
Found within a sheet of green algae on a damp seep coming out of basalt.
Algae: https://www.inaturalist.org/observations/210349442
Cool little microorganism at 40 zoom lens. Split end into 2. Cool lil dude