Diatoms exploring a large aggregate

A large aggregate in the center of this view is composed of bacteria, algal colonies, organic debris and mineral particles. Diatoms of various sizes go in and out of the particle, although it is not clear why they are doing so.

Commentary by Prof. Yuji Tsukii, Hosei University
The diatoms in this video are too small for us to see their surface pattern, which is an important criterion for their identification.

We can also see Scenedesmus acutus, a type of green algae, in the upper left corner.

A round cell on the right may be the cystic form of a flagellate or a type of Chlamydomonas. Chlamydomonas and related organisms often attach themselves to the surface of a slide or its cover glass using their flagella, and remain still. When viewed from above, they appear round. Since we cannot see any flagella in this video, we cannot be sure if it is the cyst a flagellate or the cell of a Chlamydomonas.

Sampling Date : 28 May 2009

Sampling Site : Hirose River B  Google Map