Radiolaria material in block form - how to break it up!

[MicroBob]

Hi Michael and all,

here we can collect information, thoughts and experiences on the breaking up of radiolaria material that is available in block form.

I once was promised some radiolaria material in exchange for japanese star sand. What arrived was looking like a little piece of school chalk that had been found hidden in a corner, no nice radiolaria skeletons in view!
The task is to break this up in a way that leaves the radiolaria as unharmed as possible. There are two groups of radiolaria, the skeletons of one group dissolve quickly, the other's are robust like diatoms.
Mechanical breaking doesn't work. Chemical treatment is described in link one. But calcerous radiolaria material can also be broken up by repeated freezing and thawing. This can be done old-school with the household freezer or much quicker with a Peltier cooler and a time switch. I enclose a picture of my Peltier cooler. It is important that no air can enter from the sides into the Peltier element, it would burst from ice build up otherwise. These blocks contain mostly broken radiolaria shards and the better examples have to be picked out.

To be honest - I still have my radiolaria block and haven't tested this method so far. But others had good success with it.

The better way to harvest radiolaria is on the sea bottom. Below about 4000m the water acts acidic due to the pressure and only few things survive: Diatoms, Radiolaria, a few others. Fish bones, shells etc. dissolve. I enclose an image of such radiolaria material, in air, ready to make slides from it, epi-darkfield.


Further reading (in german): Very good summary:http://www.mikrohamburg.de/Goeke/Radiolarien_gesamt.pdf
Super easy brilliant radiolaria slides: http://www.mikrohamburg.de/Programm/Pro ... 17.pdfEasy

Bob

[MichaelG.]

Many thanks for the inspiration, Bob ... Much appreciated !!

MichaelG.

[Hobbyst46]

Thanks for the protocol and images, Bob !
Although the UV cement is probably most convenient, what do you think of Pleurax for mounting Radiolaria ? surely the RI is fine, but will the Radiolaria survive the high-temperature mounting process in Pleurax, and will Pleurax fill the voids without air bubbles ?

[MicroBob]

Hi Doron,
the high r.i. of Pleurax fits fine diatoms fine, but heavily built diatoms already appear with a bit too much contrast. So the even stronger radiolaria don't benefit from an especially high r.i..
A classic mountant would be Caedax, perhaps at maximum Caedax with a bit of Aroclor
The LOCA TP 2500 stuff I use is just fine, but I don't have any proper technical data on it. Somewhere I found an r.i. of 1.51 for some kind of LOCA...
This stuff enters the radialoaria extremely good and gives very brilliant slides. I worked this out for a group meeting where quick success is a big plus and it was very successful. A marine biologist professor who held a speech on this meeting was amazed by the results and would have been glad to have this available for his work with his students in his active years.

But I think the radiolaria would survive a Pleurax mounting procedure fine and Pleurax also enters hollow ares well, so why not try it? Radiolaria are quite 3D so it makes sense to work cover slip down to have them close to it later.

Bob