An active flagellate with two flagella

This round flagellate is about 20 microns in diameter. It has two flagella of similar length at the front and back which it uses to actively swim around.

Commentary by Prof. Yuji Tsukii, Hosei University
This organism is in the genus Petalomonas, which belongs to Euglena group.

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

Petalomonas has neither a special organ for catching food, nor chloroplasts. It is characterized by a hard, flat body with a few raised ridges on the surface. Due to the lack of more precise descriptions of members of the Petalomoas genus, only a few have been classified into species. Although I have often observed this type of flagellate, I have not been able to determine what species of Petalomoans it is.

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

Sampling Date : 28 May 2009

Sampling Site : Hirose River B  Google Map