A flagellate colony on a stalk

A colony composed of about ten flagellates is attached to a long brown stalk. The stalk doesn’t move but the two flagella on each flagellate move actively.

Commentary by Prof. Yuji Tsukii, Hosei University
This organism is Anthophysa, a colony of flagellate cells.

It is interesting how the stalk, which is composed of secretions from flagellate cells, becomes thicker toward the root.

Each Anthophysa colony originates from one flagellate cell, and as the number of cells increases and develops into a colony, the amount of secreted material may increase.

It is a little puzzling why the stalk is thicker at the bottom rather than close to the colony.

Sampling Date : 18 October 2009

Sampling Site : Hirose River A  Google Map