Diatoms from northern atlantic plancton sample
Diatoms from northern atlantic plancton sample
Hi together,
yesterday we had our group meeting in Hamburg and had especailly much fun in observing a placton sample, concentrated and conserved, from the northern atlantic, about 400km south of Greenland.
today I washed the dried sample of tree slides, removed water and alcohol and cleaned the diatoms a bit by heating in an oven to 450°C. Then I mounted them in Pleurax.
Here I show a couple of photos of these diatoms.
Bob
yesterday we had our group meeting in Hamburg and had especailly much fun in observing a placton sample, concentrated and conserved, from the northern atlantic, about 400km south of Greenland.
today I washed the dried sample of tree slides, removed water and alcohol and cleaned the diatoms a bit by heating in an oven to 450°C. Then I mounted them in Pleurax.
Here I show a couple of photos of these diatoms.
Bob
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Re: Diatoms from northern atlantic plancton sample
Impressive, Bob!
Did the samples contain zooplankton as well ? if so, were they just burnt out in the oven ?
Did the samples contain zooplankton as well ? if so, were they just burnt out in the oven ?
Re: Diatoms from northern atlantic plancton sample
Hi together,
this was a complete catch, including zooplancton. I think I saw parts of it reduces to ashes in the slide. This material is from dried out slides from yesterday and I don't know what harm has been inflicted by drying under the cover slip, centrifuging and incinerating at 450°C. I still have a couple of drop of the conserved material but I have to think about how to make best use of it. A draw of an 80cm plancton net of such an expensive research ship doesn't contain much solid material so supply is limited and precious. I attatch an image taken with thee 2,5:1 Plan objective to show the general condition. The interlocked Biddulphias looked much better in the wet conserved material than in this slide.
Bob
this was a complete catch, including zooplancton. I think I saw parts of it reduces to ashes in the slide. This material is from dried out slides from yesterday and I don't know what harm has been inflicted by drying under the cover slip, centrifuging and incinerating at 450°C. I still have a couple of drop of the conserved material but I have to think about how to make best use of it. A draw of an 80cm plancton net of such an expensive research ship doesn't contain much solid material so supply is limited and precious. I attatch an image taken with thee 2,5:1 Plan objective to show the general condition. The interlocked Biddulphias looked much better in the wet conserved material than in this slide.
Bob
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Re: Diatoms from northern atlantic plancton sample
I also had a lot of bubbles in the diatoms, which I had not experienced befor in this amount.
Re: Diatoms from northern atlantic plancton sample
Hi together,
And here another picture. The long arms offer resistance in the water, as far as I know to reduce sinking.
While the cleaning by incineration doesn't work too well it helps to keep colonies together as they are in fresh condition. The individual alge in a chemical cleaned material is for me often very difficult to put into relation to its live look.
Bob
And here another picture. The long arms offer resistance in the water, as far as I know to reduce sinking.
While the cleaning by incineration doesn't work too well it helps to keep colonies together as they are in fresh condition. The individual alge in a chemical cleaned material is for me often very difficult to put into relation to its live look.
Bob
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Re: Diatoms from northern atlantic plancton sample
And here a colony that stayed together in cleaning.
Bob
Bob
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Re: Diatoms from northern atlantic plancton sample
They only get better!
Bob, please disclose the optics - is it a plan 100X oil and a darkfield oil condenser ?
Bob, please disclose the optics - is it a plan 100X oil and a darkfield oil condenser ?
Re: Diatoms from northern atlantic plancton sample
Hi Doron,
these were either taken with the Plan 40 or Zeiss Jena Apo 40/0,95 and DIC.
When everything fits perfectly the DIC should give a black backgroung in the medium position of the analyser slider. I only get a medium dark grey with my equipment.
Then I used gimp to make the background dark and adjust the light areas.
I actually took stacks of images but didn't find the time to process them.
The cleaning and mounting had to be squeezed into a day with a lot of work. I just was curious how well the cleaning worked and how good the diatoms look afterwards. This was medium successful: Some great diatoms from the fresh sample were not really presentable afterwards, some others were. What I like a lot are the diatoms with fine spines, I never had them before in a slide.
I have prepared slides from diatom material from nova scotia - completely different species though not from that far away from the point were this sample was fished.
Bob
these were either taken with the Plan 40 or Zeiss Jena Apo 40/0,95 and DIC.
When everything fits perfectly the DIC should give a black backgroung in the medium position of the analyser slider. I only get a medium dark grey with my equipment.
Then I used gimp to make the background dark and adjust the light areas.
I actually took stacks of images but didn't find the time to process them.
The cleaning and mounting had to be squeezed into a day with a lot of work. I just was curious how well the cleaning worked and how good the diatoms look afterwards. This was medium successful: Some great diatoms from the fresh sample were not really presentable afterwards, some others were. What I like a lot are the diatoms with fine spines, I never had them before in a slide.
I have prepared slides from diatom material from nova scotia - completely different species though not from that far away from the point were this sample was fished.
Bob
Re: Diatoms from northern atlantic plancton sample
And the last one, looking like a fish bone.
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Re: Diatoms from northern atlantic plancton sample
Very impressive!