I am a retired high school and community college biology instructor here in Pennsylvania who still dabbles a bit with the microscope and amateur protozoology.

This question is in relation to an observation concerning Stentor coeruleus.

I was chasing one of these specimens around on a slide of some pond water trying to out wait it to slow down for some photomicrographs. During "the chase" this particular specimen made contact with a small crustacean, perhaps a first instar cyclops.

The stentor immediately ejected a cloud of what I suppose was the pigment stentorin. This action brought the crustacean to a halt for a few seconds. I thought perhaps S. coeruleus might have been attacked by the crustacean and injured, but it swam off without any harmful effects.

This was almost octopus-like on a microscopic scale. Have you ever observed or heard of anything like this?

Robert L. Ballantyne, B.S., M.Ed., Gilbertsville, PA (rlballantyne@dejazzd.com)