A fairly large particle is pushed around by diatoms

Various kinds of diatoms are swimming around this particle, and sometimes bump into it, forcing the particle to move.

Commentary by Prof. Yuji Tsukii, Hosei University
There are a lot of similar-looking small diatoms. Therefore, to identify them by species, it is necessary to treat them with acid and compare the characteristic pattern of their cell wall using high magnification.

There is an organisms standing still in the upper-left of the video, with its contractile vacuole moving inside. From its body shape and the color of the chloroplast, it may be Cryptomonas or a related group.

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

Sampling Date : 28 May 2009

Sampling Site : Hirose River B  Google Map