A small green organism stands still near a particle. It may be a flagellate because a flagellum-like structure is briefly seen.
Commentary by Prof. Yuji Tsukii, Hosei University
I cannot detect the flagellum-like structure as described in the video comments.
Based on its blue-green cell surface, the organism may belong to the group of Dinoflagellate or genus Cryptomonas.
If we could check its side view by slowly moving the glass cover, we might be able to detect its exact features.
Sampling Date : 03 July 2009
Sampling Site : Hirose River B Google Map