How thecamoeba multiply (Arcella)

Ferry · Post by **Ferry** » Sun Oct 31, 2010 3:28 am

Admin edit: this topic was originally a reply to "Leave your teak Ameba?.....video". See note HERE. --Rik

Hi Francesco and Mitch,

I have made a drawing to explain how an Arcella divides. Follow the numbers:

no 1: this is the original Arcella.

no 2: the Arcella forms an outer part.

no 3: the outer part forms a new theca or shell. It's mostly light colored, the older ones are brown.

no 4: the Arcella divides and both individuals separate.

On the photograph you see two Arcella's which just have been separated. To the left the 'mother' and to the right the new one, much lighter of color.

In this way, all thecamoeba multiply.

Kind regards,

Ferry

Mitch640 · Post by **Mitch640** » Sun Oct 31, 2010 3:39 am

Do you have any idea how long this process takes? Can you see it build a shell? I have seen shells of all sizes also, usually the Arcella ones in orange. Do they grow bigger over time? I've never caught any of this happening.

Ferry · Post by **Ferry** » Sun Oct 31, 2010 4:44 am

Hi Mitch,

A theca doesn't grow like a seashell. Once build up, it can not be changed or repaired.
You can easily see the building of the theca if you are lucky, but the problem is that you never can see when it starts, so you will be mostly in the middle of the process when you notice it.
The shell is build up from thousands of small granules, formed in the plasmabody. These granules are made before the new theca is formed. The building of a new theca can happen fast, often within half an hour.

Kind regards,

Ferry

fpelectronica · Post by **fpelectronica** » Sun Oct 31, 2010 7:11 am

Ferry thank you very much for this interesting information
It is a pleasure to have the help of an expert
Greetings
Francisco

Mitch640 · Post by **Mitch640** » Sun Oct 31, 2010 7:19 am

The shell is build up from thousands of small granules, formed in the plasmabody.

Now that I think about it, I have seen some amoebas with what looked like granules packed into the plasma part of the body. Maybe it was ready to build a new shell. Thanks for all this information. I will now be looking for it. I seem to have as many testate amoebas in our river water here as there are parameciums. It will be easy to make a study of them.

john sp. · Post by **john sp.** » Sun Oct 31, 2010 10:21 am

Ferry, I've been following this fascinating discussion, and I just wanted to chime in with my thanks for you taking the time to provide this information about testate amoeba and how they divide. Sometimes you need to know what you are looking for to be better able to see and recognize it. I'll be looking at samples with these shelled amoeba with new eyes, now.

John

rjlittlefield · Post by **rjlittlefield** » Sun Oct 31, 2010 10:39 am

Ferry wrote:I have made a drawing to explain how an Arcella divides.

I want to add Admin's thanks also. This is a beautiful example of sharing knowledge, and that's what photomacrography.net is all about. Most appreciated!

--Rik

ABEL · Post by **ABEL** » Mon Nov 01, 2010 2:21 am

Hello.

Thank you Ferry. I not it wise. Very good explanation. I take note.

fpelectronica · Post by **fpelectronica** » Mon Nov 15, 2010 11:45 am

Hello
Reviewing old footage I found this video that can show the division of Arcella explained by Ferry
Francisco

http://www.youtube.com/watch?v=YI6giQUEGIE

john sp. · Post by **john sp.** » Mon Nov 15, 2010 2:02 pm

Very interesting Francisco. Thanks.

It looks like the more than one "daughter" amoeba was spun off by the orginal one in your video sequence.

Ferry · Post by **Ferry** » Mon Nov 15, 2010 2:28 pm

Very beautiful! It seems that first two individuals join together to exchange dna-material and afterwards they multiply!

john sp. · Post by **john sp.** » Mon Nov 15, 2010 3:24 pm

Ferry wrote:It seems that first two individuals join together to exchange dna-material and afterwards they multiply!

That's even more amazing than what I thought was going on. I never would have guessed that amoebae were capable of some kind of conjugation in their reproduction. It just doesn't fit with my prejudice of them being simple blobs of protoplasm. I'm always amazed by learning more about how sophisticated these little critters (i.e., all protozoa) really are.

Thanks again for the insight.

fpelectronica · Post by **fpelectronica** » Mon Nov 15, 2010 3:40 pm

Hello
Thanks John and Gerry for your comments
The images correspond to a film I did for quite some time and who, not knowing how to interpret, I Gave Them No Importance
Thanks to the explanations of Ferry, now I can correctly interpret the images.

Francisco

Mitch640 · Post by **Mitch640** » Mon Nov 15, 2010 4:43 pm

Amazing video. I love how things come together in this forum. The internet is the most amazing invention, making the exchange of information so easy. It's almost as astounding as watching these amoeba divide.

Charles Krebs · Post by **Charles Krebs** » Sat Dec 04, 2010 10:57 pm

Ferry,

Another vote of appreciation for this information! Amoeba tests are a constant source of amazement.