Amoeba seems to use particles

A hidden amoeba extends several pseudopodia from behind the end of one particle. The amoeba partially appears, but quickly hides by covering itself with fragments of particles. Next the amoeba appears from the end of a different particle and disappears carrying two small fragments with it. The amoeba repeatedly appears and disappears, but never completely shows itself. The behavior of the amoeba toward the surrounding particles is quite mysterious.

Commentary by Prof. Yuji Tsukii, Hosei University
It is difficult to say what this amoebae is, because the whole body is not shown in this video. The key is its characteristic pseudopodia. Large amoeba (Amoeba proteus, Trichamoeba and Polychaos etc.) do not extend pseudopodia like these. Most medium-sized amoeba (Mayollera, Saccamoeba etc.) do not extend such long pseudopodia.

The pseudopodia of Vexillifera are similar to this organism, but we cannot say whether the organism is really Vexillifera without checking its locomotive form. Dinamoeba is also known to extend a similar type of pseudopodia though I have not confirmed it.

Therefore this organism cannot be identified without checking its whole body.

Sampling Date : 08 August 2009

Sampling Site : Hirose River A  Google Map