An unknown organism

A round brown organism with a yellow tint is standing still beside a particle, but we cannot tell what it is.

Commentary by Prof. Yuji Tsukii, Hosei University
This organism may be a type of golden-brown algae, Crysophyceae, based on three main visible features:

1) The shape is round, 2) Thick yellowish-brown structure like a protoplast is noticed in the gap between the outer shell and inner cell, 3) There is a contractive vacuole in both sides of the shell.

The organism's round shape suggests that it is in a cycstic (dormant) form.

From this shape, it is difficult to decide to what genus this organism belongs.

Sampling Date : 18 October 2009

Sampling Site : Hirose River A  Google Map