Is this ciliate gluttonous?

After being collected from a paddy field, the sample was put on 1% agar plate with a drop of distilled water and kept for four days. This ciliate has already absorbed several diatoms into its body, but it still busily swims around as if hunting for more food.

Commentary by Prof. Yuji Tsukii, Hosei University
The cell of this ciliate is flat and about 100μm long. The cytostome (mouth) looks like a slit at the top of the cell. Platyophrya, Woodruffia and Enigmostoma are examples of other ciliates with a similar slit-like cystome structure.

http://protist.i.hosei.ac.jp/PDB/Im.....

http://protist.i.hosei.ac.jp/PDB/Im.....

http://protist.i.hosei.ac.jp/PDB/Im.....

The ciliate in this video is different from the above examples, and is most likely Cirrophyra. Organisms belonging to genus Cirrophyra are known to sometimes thrust out their slit-like cytostome. We can see this behavior 21 seconds into the video.

Genus Cirrophyra is also characterized by having several structures mastoid structures (like nipple) at the rear end. We cannot see such structures due to the low magnification of this video, but their presence is suggested because the posterior end of this organism is not so clear. Cirrophyra also has a contractile vacuole near the rear end, just as this ciliate does.

Sampling Date : 17 November 2006

Sampling Site : KASHIMADAI paddy field  Google Map