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Darting and dashing

A large ciliate whose whole surface is densely covered with cilia is darting around. It pauses for an instant and then dashes into a group of particles. This violent activity disturbs the peaceful habitat occupied by small algae and flagellates.


Commentary by Prof. Yuji Tsukii, Hosei University
This organism belongs to genus Frontonia. From its long, flat body, it may be Frontonia leucas.

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

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

In the first part of this video (0:06~), the organism is opening its mouth toward a glass surface, probably because it found some kind of food there. Later it gives up and swims away. In fact Frontonia swallows similar-sized diatoms, which can be seen in the following link.

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

Sampling Date : 08 August 2009

Sampling Site : Hirose River A  Google Map

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

Microbes in spaces among particles

Small Halteria ciliates and numerous diatoms are swimming in the spaces among particles. From behind one particle, a Euglena flagellate shows half of its body. Halteria and a larger ciliate busily swim around Euglena’ hiding place.


Commentary by Prof. Yuji Tsukii, Hosei University
The first organism to appear is Halteria.

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

The one appearing next may belong to the Euglenid group.

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

The organism crossing behind Euglena is more likely Frontonia leucas, or possibly F. marina.

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

Sampling Date : 18 October 2009

Sampling Site : Hirose River A  Google Map

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

A ciliate from a paddy field

The sample was observed immediately after being collected from a paddy field.

The ciliate changes its flexible body to pass through obstacles. There are several large diatoms contained inside.


Commentary by Prof. Yuji Tsukii, Hosei University
This ciliate belongs to genus Frontonia.

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

Its large, slender body is nearly 400μm long. It is probably Frontonia leucas.

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

Sampling Date : 18 July 2006

Sampling Site : KASHIMADAI paddy field  Google Map