Body (without the arms) diameter around 323 microns.
It was very nice to watch the extrusomes (I think that is how they are called) moving along the arms (axopodia).
Nikon 10x/0.45 (crop, the image quality is not as good as the 20x/0.75):

The following images with 20x/0.75:
Full frame:



Crops:


Rogelio