Euglena oxyuris is a relatively large Euglenoid, measuring 140 to 150 microns. I have never seen one swimming. In every sample I have found them in they are still, but appear to be otherwise healthy.
Michael Reese Much FRMS EMS Bethlehem, Pennsylvania, USA
They seem to be incapable of metaboly, and don't generate a lot of forward movement with that single flagellum. The stiffness is typical of the genus Lepocinclis, to which this species has been moved.