Capricious behavior of a flagellate

This flagellate has two flagella of different lengths at the front. The shorter flagellum vibrates intensively and the longer one curves around the side and extends far behind the body. The flagellate is moving in a straight line when it suddenly reverses direction by contracting and expanding the longer flagellum. The flagellate repeats this characteristic behavior many times.

Commentary by Prof. Yuji Tsukii, Hosei University
This flagellate belongs to genus Anisonema.

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

Most scientific research papers focus on Anisonema acinus. But in fact various types of Anisonema can be found in open field environments. The organism appearing in this video looks larger than Anisonema acinus.

Sampling Date : 08 August 2009

Sampling Site : Hirose River A  Google Map