An amoeba going in and out of an aggregate

This oval amoeba has a slightly stiff body 70 microns long, and extends its numerous pseudopodia in all directions. Usually it is half-hidden inside the particle, but we can catch an occasional glimpse of the whole body before it disappears completely inside the particle.

Commentary by Prof. Yuji Tsukii, Hosei University
The shape of this amoebae is greatly distorted because it has a lot of food in its cytoplasm. Amoebas are usually identified by their shape when moving. However in this video, it is difficult to determine not only the species but also to what group it belongs. The long extended pseudopodia are likely to be dactylopodia, but since many species of amoeba extend a similar type of dactylopodium, identifying this organism is also difficult even to the genus level. Similar types of amoeba are shown in the following links, but in addition to these amoeba, there may be other species which extend dactylopodia.

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

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

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

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