Stentor is a very large ciliate measuring from 500-2000 microns long when extended. There are a variety of species of Stentor.

Stentor coeruleus is a very large trumpet shaped, blue to blue-green ciliate with a macronucleus that looks like a string of beads (dark connected dots on the left). With many myonemes, it can contract into a ball. It may also swim freely both extended or contracted.

The stentor uses the cilia to sweep food down into its gullet.

Stentor polymorphus is 500-1500µm long and hosts many Zoochlorellae which makes this species green. The Zoochlorella live in symbiosis with the stentor.

Stentor are always fun to watch and are available from science supply companies. Some instructors do not have luck keeping their cultures alive.

The Stentor shown at lower left is Stentor coeruleus or Stentor polymorphus. The image was taken with a phase contrast microscope. Notice the macronucleus (round circles that look like a string of beads).

The Stentor shown below was captured by Win Aye using a petri dish under a stereo microscope at 40x magnification.

Stentors below captured by Win Aye using a microscope slide at 400x.

Stentor images and video below captured by Noah Zufari