
I was watching contractile vacuoles on some paramecium bursaria and noticed that when I shifted focus from the vacuole inside the cell to the cells surface there were always two rounded "ports" in the pellicle directly above the vacuole.
In "1a" you can see the two circular structures on the surface, and in "1b" I have quickly focused "into" the cell to show the full vacuole directly underneath. "2a" and "2b" show the same thing on a different paramecium. I checked about 4 or 5 individuals and found the same.
The inset in the lower left shows these structures with a scale bar. (Lower right shows a whole paramecium bursaria.)
I know you are supposed to be able to see the pores that empty the vacuole contents, but I've never seen them in a picture, and I've never read about two pores for a vacuole. Do you all think this is what these are?
1a, 1b, 2a, 2b, lower left inset taken with Olympus 100X, 3.3X photo-eyepiece, Canon 10D.