A feeble ciliate
This ciliate is about 100 microns long and is shaped like a leaf. The body and surrounding cilia are not moving at all except for a vacuole in the cytoplasm that is expanding and shrinking. Perhaps this ciliate is exhausted from hunting or fleeing from a predator.
Commentary by Prof. Yuji Tsukii, Hosei University
This organism must be a living ciliate because its whole body is covered by cilia, and a contractile vacuole is moving in the cytoplasm near the top. However, we cannot determine the location of the cytostome (mouth) in this video, which is an important criterion for identification of ciliates. Therefore we cannot be more specific about which type of ciliate this is. The surface to which this organism is attached may be a kind of organic material rather than a biological organism.
Sampling Date : 28 May 2009
Sampling Site : Hirose River B Google Map