A ciliate is going to divide
After being collected from a paddy field, the sample was put on DNB agar plate (diluted nutrient broth with agar) with a drop of distilled water for 4 days, and then observed.
One of the ciliates in this video is nearly ready to divide into two daughter cells. While other ciliates swim around rapidly, this one has slowed nearly to a standstill.
Commentary by Prof. Yuji Tsukii, Hosei University
This ciliate belongs to order Stichotrichida.
This cell is obviously about to divide. The surrounding ciliates may be the same species.
When these swimming ciliates change direction, the tops of their cells also bend toward the new direction. Therefore these ciliates probably belong to genus Oxytricha.
However, according to the Monograph of the Oxytrichidae (Ciliophora, Hupotrichia) by Helmut Berger : Kluwer Academic Publishers, 1999, 113 species with similar shapes are included in genus Oxytricha. Therefore identification of this ciliate to the species level is almost impossible.
Sampling Date : 22 September 2006
Sampling Site : KASHIMADAI paddy field Google Map