Two ciliates taking turns

A large, dark, oval ciliate is busily foraging around particles. Soon another type of ciliate with a slender shape joins in the foraging. Eventually the first one leaves to search for food elswhere.

Commentary by Prof. Yuji Tsukii, Hosei University
The first ciliate is a smaller organism belonging to the genus Frontonia.

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

A second ciliate with a slightly slender shape appears in the later part of this video. The shell of a diatom inside its cytoplasm indicates this ciliate may also be Frontonia, which has swallowed this diatom shell. In Japanese Frontonia is called “Kuchisake-mizukemushi”. This Japanese name suggests an organism that often swallows food that is longer than its body. This may be why the organism becomes elongated.

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

It is difficult to determine the exact species for two reasons. First, the front view of the organism is not clear in this video. Second, many types of Frontonia remain unclassified, so identification of this organism is rather difficult.

Sampling Date : 09 August 2009

Sampling Site : Hirose River B  Google Map