Thuricola folliculata with interesting detail

ralfwagner · Post by **ralfwagner** » Mon Mar 26, 2007 12:24 pm

Hello,

recently Bernhard showed us some nice pics of Thuricola folliculata with green Zoochlorellas inside. So I went out to my favourite place where to find these critters and took some pictures, too.

On the pic I am showing here, there is some interesting detail that is new to me and probably to most folks here in the forum: a small ring around the body, approximately at the level of the lorica's valve (yellow arrow in the inset). This ring is very similar to that of Cothurnia annulata, but much finer. Although I took about 50 pics the ring shows up only on the one shown here. This means that you have focus very exactly if you want to see it.

According to Wolfgang this ring is described neither in the books of Kahl nor Foissner. But I found a pic on the Protist Server that shows the surrounding ring on a Thuricola folliculata, too ( http://protist.i.hosei.ac.jp/PDB/Images ... ricola.jpg ).

In the German forum ( http://www.mikroskopie-forum.de/read.ph ... #msg-29208 ) there is also a suggestion that it may be the beginning of a cell division.

However, last but not least a small video (DIVX-coded) showing that critter at work.

http://www.dr-ralf-wagner.de/Bilder/Thu ... culata.avi

Enjoy!

rjlittlefield · Post by **rjlittlefield** » Mon Mar 26, 2007 1:48 pm

Very nice still photo, Ralf, but it was the video that really took me by surprise.

The action of the cilia appears to be strongly non-symmetric, like they are stroking on one side of the head and not moving at all on the other.

I can't think of any way that the video could have introduced this effect, but I have to ask -- do they really work like that?

--Rik

ralfwagner · Post by **ralfwagner** » Tue Mar 27, 2007 10:08 am

Hello Rik,

yes, they really work like that.

I suppose that the missing symmetrie can be explained by two items:

a) the time resolution of my Canon A85 in video-mode is only poor: 10 fps. So it is able to resolve only the slower moving cilia.

b) I used here my 63x/0,8 Zeiss Achroplan objective. The layer that is shown sharp with this objective is really thin and the head of that Thuricola is really thick. So, if you have the cilia at the left and right border in focus, there no chance to see the others in middle of the head, because they are out of focus.

I' m not quite sure if my explanation tells the whole truth, but I believe it can't be far away.

beetleman · Post by **beetleman** » Tue Mar 27, 2007 2:21 pm

Wonderful Video Ralf.

Charles Krebs · Post by **Charles Krebs** » Sun Apr 01, 2007 4:00 pm

Ralf,
Always interesting to:
A) See a creature that you have not seen before, or
B) to observe something about a fairly common creature that is unusual and not well referenced.

Thanks for showing us a "B". It is now something I will look for closely if I encounter this species.

ralfwagner · Post by **ralfwagner** » Mon Apr 02, 2007 9:56 am

Hello,

meanwhile, together with some folks from the German forum, the nature of this ring could be clarified. It is developed by the Thuricola in preparation of the so called swarmer-state. In the swarmer state the Thuricola is not fixed in its lorica anymore. The lorica is leaved and the critter is searching for a new place to settle down. The ring consits of cilia surrounding the Thuricola's body and it can be interpreted as an swimming-aid. Bern Laber presented very detailed pics of that ring in the German forum. The cilia of the ring are clearly visible in his pics:

http://www.mikroskopie-forum.de/read.ph ... #msg-29208