Cosmarium subcucumis---My mystery for 2007

ralfwagner · Post by **ralfwagner** » Sat Feb 03, 2007 2:33 pm

Hello,

perhaps do some of you remember: in spring last year I introduced myself to this forum with fotos and a video of a degenerated stentor http://www.photomacrography1.net/forum/ ... ht=stentor

Now I found another mystery, a strange cosmarium subcucumis. I do not know whether we see here an early state of sexual reproduction or a degenerated individual of that desmid. Who knows more about that?

For comparison, here is a normal one:

beetleman · Post by **beetleman** » Mon Feb 05, 2007 6:33 am

Whatever it is Ralf, you did a great job capturing it. I`m sure with the group here, we will find an answer.

MacroLuv · Post by **MacroLuv** » Mon Feb 05, 2007 7:54 am

Nice finding.

But can you briefly explain to ignoramus in this field how you are sure that you are dealing with same species?

bernhardinho · Post by **bernhardinho** » Mon Feb 05, 2007 9:05 am

MacroLuv wrote:Nice finding.
But can you briefly explain to ignoramus in this field how you are sure that you are dealing with same species?

Hello

quite simple: desmids are always bilateral. There aren't any threepart ones, unless some sort of division goes on. But I don't have an explanation to the pic Ralf is showing.

Bernhard

Thomas Ashcraft · Post by **Thomas Ashcraft** » Mon Feb 05, 2007 9:13 am

Hi Ralf,

For some reason I cannot open your picture above of the degenerated cosmarium. I can see the normal one though.

Can everyone else open the pic or do I need to make an adjustment in my own pc?

Thanks.

Tom

rjlittlefield · Post by **rjlittlefield** » Mon Feb 05, 2007 9:18 am

Thomas Ashcraft wrote:Can everyone else open the pic or do I need to make an adjustment in my own pc?

Both work for me. But I notice that they're coming from different servers. Could be a network issue. Try just refreshing the page a couple of times.

--Rik

ralfwagner · Post by **ralfwagner** » Mon Feb 05, 2007 11:37 am

Hello MacroLuv,

Bernhard just said it all.

All I can add is: Have a closer look at the middle part. This looks like the normal form. And to the right and ledt side of this middle part there seems to grow additionally one half of the desmid, too. This is unusual.

ralfwagner · Post by **ralfwagner** » Mon Feb 05, 2007 11:42 am

Hello Thomas,

there seems to be nothing wrong with the pics. Please try what Rik advised. If this doesn't work please tell me and I will send you an email with that pic.

MacroLuv · Post by **MacroLuv** » Mon Feb 05, 2007 12:00 pm

Thanks Ralf and Bernhard.

You are right... as I look closer...
I counted #1 as four part, not 1 + 2 x 1/2. My fault, didn't follow membrane, darker stripes on #1 fooled me somehow.

Charles Krebs · Post by **Charles Krebs** » Tue Feb 06, 2007 11:36 am

Ralf... While I can offer no answer, I took the opportunity presented by your post to learn a little about the reproductive processes of desmids. I had been puzzled by certain objects I found on my slides these past few years and I now realize that they are desmid zygospores. So while I didn't find anything to answer your mystery, your post helped me answer a couple of mine!

I was surprised at the amount of study that has been done on this topic. For me, this page was concise and instructive.
http://www.desmids.nl/info/reproductie/ ... ction.html

Wim van Egmond · Post by **Wim van Egmond** » Thu Feb 08, 2007 2:51 am

Hello Ralph,

Those are interesting images! I see that Charlie linked to our dutch desmids club site!

I asked Peter Coesel who is a desmids specialist and writes the articles for the desmid site about the pictures you made.

He says it is an oaccasionally observed phenomenon. It is an error during the cell division. After the fission of the nucleus the newly formed semicells don't form the separating waist, the isthmus.

I translate this from a dutch e-mail so I hope I write this correctly.

Dr. Coesel thought it would be interesting to write a bit more about this phenomenon on the desmid site. Would it be possible to use your image for that?

For those who are interested in desmids, feel free to contact the people from the desmids website. It is a club of enthusiasts!

best regards

Wim

ralfwagner · Post by **ralfwagner** » Thu Feb 08, 2007 11:46 am

Hello Wim,

thank you and Dr. Coesel for that explanation

. My understanding of that is, that it is an error during the vegetative cell reproduction and not an error during the sexual reproduction. Is that right?

Of course I will allow Dr. Coesel to use my picture on his website, provided that it will be a non-commercial use and he will mention my copyright and if possible my website. Dr. Coesel should contact me directly via my email mikroskopie ( at ) dr-ralf-wagner.de. I will send him a picture with a better resolution than shown here.

I am already curios what Dr. Coesel will write further about that phenomeneon.

greetings from Düsseldorf to the Netherlands

Wim van Egmond · Post by **Wim van Egmond** » Mon Feb 12, 2007 4:46 am

Dear Ralph,

It took some time for me to react.

Thank you for your offer to let them use the image. And of course it will be according to all your wishes regarding copyright etc.

I will ask Dr. Coesel to e-mail you!

Yes, it is after vegetative cell reproduction!

If anyone has questions about desmids feel free to contact the people behind the desmids.nl website!

best regards from Rotterdam upwards the river!

Wim