Flagellates and ciliates gathering around a food source

Various sizes of flagellates and ciliates are swimming around, and they sometimes enter aggregates containing a variety of foods. One of the large ciliates is 400 microns in diameter, dark brown and oval shaped. The side-view of the organism shows it is slender, slightly narrow at both ends, and entirely covered with short cilia. Its motion has become slow because it is bloated with food from successful foraging.

Commentary by Prof. Yuji Tsukii, Hosei University
The leading character in this video is Frontonia acuminata. In contrast with other ciliates in the Frontonia group whose cytostome is located in the center of the “abdomen”, the cytostome of Frontonia acuminate is slightly shifted from the actual center. In this way the organism resembles Disematostoma, but from other criteria, it can be identified as Frontonia. For example, the top of Disematostoma is slightly pointed, but the top of this organism is round like others in the Frontonia group.

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

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

Two other ciliates is Holosticha polystylata and the one belonging to Remanella.

Sampling Date : 27 May 2009

Sampling Site : Hirose River A  Google Map