Detailed Lesquereusia amoeba test

Charles Krebs · Post by **Charles Krebs** » Mon Nov 29, 2004 11:37 pm

I posted a Lesquereusia amoeba a while back, but it was more a "see-through" picture viewing the amoeba inside. I've kept an eye out for a specimen that could really show the construction of the test itself. This one fit the bill, but I didn't want a picture that showed just a small piece in focus, so it took 15 stacked images to bring it all into focus.

These tests are made up of "siliceous platelets" in an "organic matrix", "composed of sulfomucin complexed with basic protein". (quotes credit ttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi? ... t=Abstract)

This particular test is about 125 micron in long dimension.

Kenv · Post by **Kenv** » Mon Nov 29, 2004 11:53 pm

First its an amazing structure, secondly you have a helluva lot of patience Charlie - 15 stacks!! Well done.
Ken

Steve West · Post by **Steve West** » Tue Nov 30, 2004 6:19 am

Fascinating. Do you mostly find your tests in bottom debris?

Steve

twebster · Post by **twebster** » Tue Nov 30, 2004 7:38 am

This is beautiful, Charles.

It looks like some sort of micro-amoebic brain.

Charles Krebs · Post by **Charles Krebs** » Tue Nov 30, 2004 11:28 am

Steve... Basically yes. My little treasure trove is from a sample that I sqeezed out from mosses in a steam in Mt Rainier NP back in August. I also inadvertantly got some dirt included as well. I've kept it in a container by a window since then. If I take two or three drops in an eyedropper from the sediment at the bottom I seem to get a at least a dozen or more tests. At this stage, the majority of these are empty, and some are pretty ratty looking. But after a few minutes I often find one or two "active" ones, and occasionally I find a gem such as this one. One problem in photographing these is that the eyedropper also picks up some sand grains as well, so the cover glass will rest on these. The tests sink to the bottom so sometimes it's tough to get a good image through the 40X (if I can focus on them with it at all).

Guess I need one of those silly looking inverted microscopes

By the way, this is also the sample that has produced the water bears as well.

Frez · Post by **Frez** » Tue Nov 30, 2004 8:03 pm

That's just amazing! Congratulations on a job so very well done. Do you find this particular type of test rare? It's a true oddity in my world.

Frez

Ken Ramos · Post by **Ken Ramos** » Wed Dec 01, 2004 3:50 am

Charlie...here lately, I have noticed, you've become a little bit testy in your work!

But, however, you are coming up with a lot of wonderful testate shots. Very interesting...

Guest · Post by **Guest** » Wed Dec 01, 2004 3:36 pm

Frez... have to admit I don't know how common these are around my parts. Only been looking for them a short time. But now that I have an idea where/how to look, I seem to come upon them pretty regularly (at least from one of my sampling locations).

Ken(V)... 15 images is more than I like to play around with manually, but with an object that is fairly spherical it goes relatively quickly. It probably took about 1.5 hours to do this one, working with the full size 18 meg (2048x3072 pixel) files.

I thought it might be of interest to show what just one "slice" looked like, and to compare it to the completed image. For me it really illustrates what a valuable tool digital imaging is. When you look at a subject like this on the scope, you unconsciously adjust the fine focus as your eye moves around. You establish a "complete" image in your mind of the subject. To show the complete subject it in a single photograph is frustrating.

Kenv · Post by **Kenv** » Wed Dec 01, 2004 5:28 pm

Thanks for that info Charlie, I can see the size of the job now. Also thanks for the technique, I have filed it away for future use.
Kenv