Library > Name > Amoeba(Vexillifera)

Travel of amoeba

An amoeba extends a number of fine pseudopods and moves very slowly. Here its movements is sped up to 10 times the normal speed, so it appears to be moving quickly. A large particle attached to the back of the amoeba is being dragged along by the organism. When it arrives at the surface of an aggregate, the amoeba squeezes its flexible body through a narrow opening, leaving the particle behind.


Commentary by Prof. Yuji Tsukii, Hosei University
This amoeba is Vexillifera or closely-related organism.

Its method of locomotion is similar to that of Mayorella, but unlike Mayorella, this organism extends many narrow pseudopodia (Dactylopodia) forward.

This Vexillifera is quite large.

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

Sampling Date : 03 July 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 III

When the amoeba concentrates on catching food using one or two pseudopodia, the remaining pseudopodia become very short. When many food particles approach all at once, the amoeba becomes confused and cannot decide which pseudopodium to extend. When this happens, the hunt is a complete failure.


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

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

Journey of amoeba with particles

A hidden amoeba extends several slender pseudopodia from behind the end of one particle. As the amoeba comes to other particles, it extends pseudopodia from behind the one of particle. As the amoeba never shows itself completely, we cannot recognize where it is. In the meantime the amoeba and several particles begin journey to another place together with a colony of flagellates.


Commentary by Prof. Yuji Tsukii, Hosei University
Two types of amoeba take turns appearing in this video.

The first one is Vexillifera.

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

The second one, which is in a shell covered with black particles, may be Diaphoropodon.

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

Diaphoropodon is characterized by fine spiny projections on the surface of its shell, but to see these projections clearly requires higher magnification and resolution.

Sampling Date : 09 August 2009

Sampling Site : Hirose River B  Google Map

Encountering of two different amoebae I

Here a large amoeba is actively hunting and catching food one by one. After a while, a different amoeba appears in our field.


Commentary by Prof. Yuji Tsukii, Hosei University
The first amoebae to appear may be Vexillifera or a floating Vannella.

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

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

Amoebae appearing later may be Diaphoropodon, which is in a shell covered with black particles.

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

Diaphoropodon is characterized by fine spiny projections on the surface of its shell, but to see these projections clearly require higher magnification and resolution.

Sampling Date : 09 August 2009

Sampling Site : Hirose River B  Google Map

Encountering of two different amoebae II

Two kinds of amoebae of different size and shape are coming in contact with each other, and then move away.


Commentary by Prof. Yuji Tsukii, Hosei University
The amoebae shown in the upper part of the video may be Vexillifera or floating Vannella.

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

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

The amoebae appearing later may be Diaphoropodon, which is in a shell covered with black particles.

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

Diaphoropodon is characterized by fine spiny projections on the surface of its shell, but to see these projections clearly requires higher magnification and resolution.

Sampling Date : 09 August 2009

Sampling Site : Hirose River B  Google Map

An active amoeba

An amoeba 100 microns in length actively moves using its many slender pseudopodia. In the cytoplasm, we can see a contractile vacuole and numerous particles that were probably captured as food.


Commentary by Prof. Yuji Tsukii, Hosei University
This is Vexillifera, a comparatively large amoebae. The shape and color of the cell body are similar to Mayorella, but unlike Mayorella, it extends several long, thin pseudopodia called dactylopodia.

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

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

Sampling Date : 28 May 2009

Sampling Site : Hirose River B  Google Map