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Behavior of Euplotes

Behavior of Euplotes A large ciliate called Euplotes is gathering food with the dense cilia around its mouth. Small flagellates are sucked into the mouth one by one. They are transferred to the food vacuole which already contains plenty of food. One of the caudal cirri near the rear end shows characteristic movement. At first the body seems to be flat when viewed from above. When the organism moves over to a particle, we can see it from the side. It almost lookes like a turtle holding onto the particle with its "hairy legs" (cirri).


Commentary by Prof. Yuji Tsukii, Hosei University
It is difficult to say whether this organism is Euplotes eurystomus or E. woodruffi, because the exact shape of its nucleus cannot be identified.

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

Sampling Date : 03 July 2009

Sampling Site : Hirose River B  Google Map

Waiting and hunting

Lurking behind some particles, this ciliate (which may be Pleuronema) is waiting for food. The transparent membrane extending from the side of the body captures small flagellates. Some of these flagellates are carried into the food vacuole, but others manage to get free.


Commentary by Prof. Yuji Tsukii, Hosei University
This organism belongs to genus Pleuronema.

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

The organisms can be identified as Pleuronema marinum from its large cell size and other features at the rear end.

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

Sampling Date : 03 July 2009

Sampling Site : Hirose River B  Google Map

Strobilidium hunting technique I

Hunting technique The shape of this ciliate called Strobilidium reminds us of a bell or strawberry. Although the body shape is similar to Vorticella, it does not have a stalk, yet like Vorticella, it rotates in a continuous arc. The whirlpool created by the rapid waving of the cilia surrounding its mouth pulls food into the organism.


Commentary by Prof. Yuji Tsukii, Hosei University
This organism is Strobilidium.

The Protozoological Monograph, vol.3, 134, 2006 (Kreutz & Foissner), depicts the figure of Strobilidium with a narrow string at its rear end, and describes the organism as exhibiting rotatory movement while attaching itself to a surface by its string.

Sampling Date : 03 July 2009

Sampling Site : Hirose River B  Google Map

An amoeba hunting for food I

Here a large amoeba is actively hunting and catching food in various ways. When a food particle becomes caught on the tip of the pseudopodium, the pseudopodium carries the food to the center of its body, by becoming shorter and broader until the food is engulfed.


Commentary by Prof. Yuji Tsukii, Hosei University
This organism is possibly a floating Vannella.

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

It usually attaches onto solid surfaces and appears like a flat fan, but when it is torn off from the surface by water movement, it transforms into a radial shape.

Floating in water, Vanella expands its narrow pseudopodia to find a new surface to which it can attach.

Vanella looks for food - bacteria and small protozoa - as it moves along solid surfaces.

Sampling Date : 09 August 2009

Sampling Site : Hirose River B  Google Map

An amoeba hunting for food II

When a ciliate or flagellate accidently runs into the amoebas body, two pseudopodia tightly grasp the unlucky prey and transfer it to the central part. At first the prey struggles to get free, but soon stops moving. Finally the prey loses its shape and becomes unrecognizable.


Commentary by Prof. Yuji Tsukii, Hosei University
This organism resembles Vanella in its radial shape, but unlike Vanella, it catches food while floating freely. The organism may be Vexillifera or it may belong to a related family.

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

It sometimes moves on a solid surface, while at other times it proceeds while swaying its long pseudopodium in front.

An important criterion for classifying amoeba is their method of locomotion. Since amoeba appear similar when they are floating, it is difficult to determine what species this organism is.

Sampling Date : 09 August 2009

Sampling Site : Hirose River B  Google Map

An amoeba hunting for food I (Long Version)

Here a large amoeba is actively hunting and catching food in various ways. When a food particle becomes caught on the tip of the pseudopodium, the pseudopodium carries the food to the center of its body, by becoming shorter and broader until the food is engulfed.


Commentary by Prof. Yuji Tsukii, Hosei University
The beginning of this video, the amoeba looks like it might be a floating Vannella, which is difficult to distinguish from Vexillifera.

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

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

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

Later in the video, we can see the triangular-shaped lobopodium, which is characteristic of Vexillifera.

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

However, since the organism in this video is continuously floating, it is difficult to say with certainty whether it really is Vexillifera.

Sampling Date : 09 August 2009

Sampling Site : Hirose River B  Google Map

An amoeba hunting for food II (Long Version)

When a ciliate or flagellate accidently runs into the amoebas body, two pseudopodia tightly grasp the unlucky prey and transfer it to the central part. At first the prey struggles to get free, but soon stops moving. Finally the prey loses its shape and becomes unrecognizable.


Commentary by Prof. Yuji Tsukii, Hosei University
The organism is Vexillifera.

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

Sampling Date : 09 August 2009

Sampling Site : Hirose River B  Google Map

Euplotes: a skillful hunter

A large Euplotes ciliate has characteristic cirri at the front and rear ends of its body. By actively waving the cilia surrounding its mouth, it creates a whirlpool to attract food particles. Several prey are drawn into its mouth and transferred inside, but some manage to get free.


Commentary by Prof. Yuji Tsukii, Hosei University
This organism is Euplotes.

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

From the cell shape, it may be E. eurystomus or E. woodruffi.

To determine the species, examination of the macronucleus shape is necessary.

Sampling Date : 18 October 2009

Sampling Site : Hirose River A  Google Map

Coleps: a fierce hunter

A feeble ciliate is bitten by a Coleps. The poor ciliate desperately struggles to get away. However, the bite causes the inside particles to come out of the ciliate. These particles are eaten up one by one by other organisms. Finally Coleps and other ciliates attach themselves to the prey, and within a few seconds the last traces of the poor ciliate are consumes completely.


Commentary by Prof. Yuji Tsukii, Hosei University
This interesting video needs no additional comments.

Sampling Date : 19 October 2009

Sampling Site : Hirose River A  Google Map

Conjugating ciliates attacked by Coleps

A pair of conjugating Oxytricha of different sizes are suddenly attacked by a Coleps. The smaller Oxitricha is bitten nearly in half, which causes the bonding pair to move their cilia intensively in a frantic effort to escape. Finally the pair separates, and the dwarf and the giant swim off in different directions.


Commentary by Prof. Yuji Tsukii, Hosei University
This interesting video needs no additional comments.

Sampling Date : 20 October 2009

Sampling Site : Hirose River A  Google Map