Library > Name > Stylonychia

Ciliate in the process of division

In this view of a dividing ciliates, the process of division is almost finished, but two daughter cells are still connected. The cirri around the mouth and rear end are usually moving even when the body is still. However, the cirri can provide "rowing power" to move away from another organisms when necessary. After a while, a wall between the two daughter dells develops, and finally the completely divided cells go their separate ways.


Commentary by Prof. Yuji Tsukii, Hosei University
The three long cirri at the rear end indicate that this organism may be Stylonychia.

http://protist.i.hosei.ac.jp/PDB/Im.....

Sampling Date : 03 July 2009

Sampling Site : Hirose River B  Google Map

Ciliate feeding behavior

A large flat ciliate, which may be Euplotes, feeds by standing still, moving only the cirri surrounding its mouth and rear. We can see plenty of food in its vacuole.


Commentary by Prof. Yuji Tsukii, Hosei University
This organism is likely to be Stylonychia mytilus, although we cannot see three cirri at the rear end when typically there are three.

http://protist.i.hosei.ac.jp/PDB/Im.....

Even in Helmut Berger’s, Monograph of the Oxytrichidae (Ciliophora, Hypotrichia), Kluwer Academic Publishers, 1999, there are no Stylonychia having only one cirrus. We can assume that this organism may have lost its other two cirri.

Sampling Date : 03 July 2009

Sampling Site : Hirose River B  Google Map

Large and small ciliate hunting

A Strobilidium and a Stylonychia are feeding close to each other. Both ciliates are trying to attract food particles by moving the cilia around their mouths. However, the strong whirlpools that they both create interfere with each other's efforts. After a while, they change their strategy and move to separate places to feed.


Commentary by Prof. Yuji Tsukii, Hosei University
It is difficult to determine whether this organism is

Strobilidium

http://protist.i.hosei.ac.jp/PDB/Im.....

or Strombidium.

http://protist.i.hosei.ac.jp/PDB/Im.....

Sampling Date : 03 July 2009

Sampling Site : Hirose River B  Google Map

Foraging Euplotes

This large ciliate forages for food as it stands still among algal cells and particles. Its strategy for catching food is to vigorously move the cilia surrounding its broad mouth as it waits for small organisms to pass nearby and be sucked inside. In the course of our observation, several small organisms are drawn into the body, followed by a diatom and a flagellate. However, some of them are rejected and cast out through the membrane.


Commentary by Prof. Yuji Tsukii, Hosei University
This organism is not Euplotes, as in the title states, but Stylonychia.

http://protist.i.hosei.ac.jp/PDB/Im.....

http://protist.i.hosei.ac.jp/PDB/Im.....

We can easily distinguish Stylonichia and Euplotes if we know what to look for.

Euplotes has a few large cirri around the top, slightly behind the center, and at the rear end; but there are no small cirri along the sides. On the other hand, Stylonychia has small cirri around its oral part (peristome) and lining both sides of the body. Stylonychia also has three long caudal cirri extending backward.

Stylonichia and Euplotes largely differ from each other in the number and shape of their macronuclei, although we cannot distinguish these characteristics in living organisms. Stylonichia has two ellipsoidal macronuclei (one at the top and another at the rear), whereas Euplotes has one large macronucleus with various shapes depending on the species, such as T-shaped and C-shaped.

Sampling Date : 27 May 2009

Sampling Site : Hirose River A  Google Map

Foraging and excreting

Euplotes creates a whirlpool to capture various sizes of microorganisms, including bacteria, small flagellates and even larger diatoms. The prey can be observed at higher magnification inside the body of Euplotes. However, diatoms are frequently thrown out, probably because they are hard for Euplotes to digest.


Commentary by Prof. Yuji Tsukii, Hosei University
This organism is not Euplotes, as in the title states, but Stylonychia.

http://protist.i.hosei.ac.jp/PDB/Im.....

http://protist.i.hosei.ac.jp/PDB/Im.....

We can easily distinguish Stylonichia and Euplotes if we know what to look for.

Euplotes has a few large cirri around the top, slightly behind the center, and at the rear end; but there are no small cirri along the sides. On the other hand, Stylonychia has small cirri around its oral part (peristome) and lining both sides of the body. Stylonychia also has three long caudal cirri extending backward.

Stylonichia and Euplotes largely differ from each other in the number and shape of their macronuclei, although we cannot distinguish these characteristics in living organisms. Stylonichia has two ellipsoidal macronuclei (one at the top and another at the rear), whereas Euplotes has one large macronucleus with various shapes depending on the species, such as T-shaped and C-shaped.

Sampling Date : 27 May 2009

Sampling Site : Hirose River A  Google Map