Cilia motion repels surrounding organisms

The whirlpool created by this Strombidium's cilia motion is so strong that small organisms are pulled toward the Strombidium, only to be repelled by the water current. Occasionally the Strombidium manages to capture food using the whirlpool hunting strategy.

Commentary by Prof. Yuji Tsukii, Hosei University
This organism may be either Strombidium or Strombilidium.

Both organisms are distinguished by the pattern of cirri at the front end of the cell, that is whether line of cirri is closed or whether line of cirri is not closed but extends to backward.

But it is difficult to decide without checking the side view of a motionless cell.

This organism seems to be Strobilidium elegans.

Sampling Date : 18 October 2009

Sampling Site : Hirose River A  Google Map