Nice diatom

bernhardinho · Post by **bernhardinho** » Fri Feb 15, 2008 2:24 pm

Hi folks

here is a nice double. Embarassingly I don't have an 100% ID as I'm not that much an expert on diatoms. Maybe you guys from France know

Obj. Leitz EF 100x P Oil, 10x Leitz Periplan, Coolpix 990, flash

Bernhard

Adrian · Post by **Adrian** » Fri Feb 15, 2008 7:43 pm

beautiful specimen

ralfwagner · Post by **ralfwagner** » Sat Feb 16, 2008 1:01 am

Bernhard,

its a Pinnularia after cell division. Maybe P. viridis. Try to burn them and then take new pics!

bernhardinho · Post by **bernhardinho** » Sat Feb 16, 2008 6:04 am

ralfwagner wrote:Bernhard,

its a Pinnularia after cell division. Maybe P. viridis. Try to burn them and then take new pics!

Thanks Ralf!

So its shortly before they separate?. I prefer to leave this burning buisness to you well trained chemistry guys

Greetings from Bochum via US Server to Düsseldorf

Bernhard

ralfwagner · Post by **ralfwagner** » Sat Feb 16, 2008 8:50 am

Bernhard,

indeed, shortly before they separate. Interesting and well shown in your pic is, that the left diatom is a bit smaller than the right one. This is because diatoms regenerate always the smaller half of the cell when dividing. In this way they get smaller and smaller with every division step until a certain lowest level is reached. At this point sexual reproduction takes place resulting in individuals of "normal", larger size.

When we meet at Ursula I can show you how to treat them with sulfuric acid in order to reveal the fine structures of the diatoms.

Gretings to Bochum from sunny Düsseldorf.

Gyrosigma · Post by **Gyrosigma** » Sat Feb 16, 2008 10:14 am

Hello Bernhard
I agree with Ralph about Pinnularia, the difficulty here is that the diatoms are on girdle view that is not correct for a complete ID...
The valve view could be something like that...

if you saw some under your microscope it is good for the ID

best regards

Dominique

bernhardinho · Post by **bernhardinho** » Sat Feb 16, 2008 10:46 am

Hi Dominique

yes, these I've seen many times and would have recognized. I was sort of assuming it could be Pinnularia, but I had never seen these edge on.

Salut

Bernhard