Strange little microscopic creatures

[DarioC]

Generally I am on the Physics Forum, but I got my hands on a good microscope a while back and decided to grow some little dudes to look at. My third incubation batch consisted of filtered drinking water and a bit of stuff from my mulch pile. Grew a few interesting little guys and looked them up online.

Fourth batch I put in some grass with roots from my front yard. After about 3 days, WOW.

I missed them at first because they were very small compared to what I had been seeing, even on 400X magnification. Much smaller than anything I had seen before and VERY active. They were concentrated on what looked like small pieces of "skin" cells from the grass shoots. Not sure about that. First time I saw them they just looked like tiny dots but took on a more or less oval shape when they moved away from their "perch." This was in a drop of water on a glass slide. There must have been thousands of them, but very tiny and moving very fast.

Next day I could not see them any longer, but I think the debris I saw was dead ones.

At first I thought the water might have had something in it that killed them as I know they add minerals for taste, but I think it was actually that they were not meant to live in water (thus the clumping on the pieces of grass "skin."

Are these just smaller versions of what I normally find, or something else. I am going to do the experiment again in a slightly modified way.

All suggestions/info appreciated.

 

[DarioC]

Well, I started a repeat of the grass, roots 'n dirt sample in drinking water early today and got a look at a bit of the water under the microscope tonight. Didn't figure I would see much so soon.

I'm trying to find a way to put tiny drops of sample water on the slide so I can use the X400 objective without getting it into the drop and screwing up everything.

Finally managed to do that, but even better, I found a variation on the familiar cross-lighting method of improving image contrast and definition. The original version uses an available accessory on the Nikon to kinda cast a shadow on the object being observed. You can cheap out and place a dime on the bottom condenser lens and get similar results. The results of both methods are high contrast, but not so detailed.

For some reason I picked up a small square of typing/printing paper that I use for notes and placed the edge part way across the bottom condenser lens. Holy crap, I could suddenly see all kinds of little guys in beautiful detail that were completely invisible in simple back lighting.

It must be the "transparency" of the paper that produces that result. You get contrast from the edge effect, but it is filled with detail from the light coming through the paper. (You have to turn up the light source considerably).

The size, shape, and detail improvement was amazing. There were all kinds of things visible in detail of various sizes, and some really tiny ones moving around similar to before, just not as many. (The sample had been in water only about 8 hours).

I have to try this with a fixed non liquid sample and the X1000 lens with immersion oil. Perhaps also using various colored transparent plastic with the edge technique above.

Interesting and fun evening.

 

[Andy Resnick]

<snip>

For some reason I picked up a small square of typing/printing paper that I use for notes and placed the edge part way across the bottom condenser lens. Holy crap, I could suddenly see all kinds of little guys in beautiful detail that were completely invisible in simple back lighting.
<snip>

It's tough to tell, but I suspect you re-discovered 'oblique illumination':

http://micro.magnet.fsu.edu/primer/techniques/oblique/obliqueintro.html

1/2-way down the page shows the effect.

 

[DarioC]

Yep, as mentioned in my second post above. Have used it with a dime on the bottom condenser lens and with a led side-light fixture on the lower magnifications. I thought the light coming through the paper edge was making a difference on the details as compared with an opaque material. It is hard to tell with some views.

Three days running on this sample and things are still active. Fourth day is the charm. Wondering if there might be some nutrient material I might put in the mini pond.

Just yesterday got my skills up on practical use of glass covers and immersion oil with the X1000 objective. Works pretty good. There are an awful lot of REALLY small guys mucking around the bits and pieces of flotsam.

Might have to go shopping for an electron microscope soon, Ho Ho.

DC

 

[DarioC]

Great link Andy, thanks very much. Impressive content. I will try the offset slit version for sure.

This morning there are a large number of "medium sized" motators when I took a quick look at a sample at X400. They are past the time limit of before. Teenagers, chuckle? Wonder if the small pinch of sugar I put in helped? I've been more careful to put the container outside during the day than I was before. Figured the warmth and daylight would help.

Many straight-sided ones, like a short stick. Haven't seen that before. Still quite small so I will take a look on X1000 later.

DC

 

[Andy Resnick]

Post some pics!

 

[DarioC]

Great idea, and I would be glad too, but the microscope is only binocular. Don't presently have a camera that would be suitable to use with an adapter and finally the little guys are not going to hold still for a portrait. I have some way to go before I get into micro photography and specimen preparation.

 

[berkeman]

Try hand-holding your cell phone camera to one of the objectives -- some cameras can just shoot at the exit pupil of the objective. Won't be super images, but still can be useful for posting here...

 

[aroc91]

Try hand-holding your cell phone camera to one of the objectives -- some cameras can just shoot at the exit pupil of the objective. Won't be super images, but still can be useful for posting here...

I will second this and say that it works quite well. I've taken quite a few pictures like that for research I did last year. I've attached one of the shots I used-

 

[DarioC]

That is a pretty nice shot when you bring it up to full size.

I have a couple of "cheap" digital cameras. They were made before the manufacturers got their act together. Awkward.

My photography skills are more like Nikon film cameras. I guess it might be fun to try, what with the LCD viewfinder. Still, all I think I will get is the chunk of debris the little guys are swimming near. A shot of one of the big guys might be interesting. Might luck out on the small ones though.

 

[DarioC]

Tried photos with my old technology digital; it works, but not very well.

Today I found where everyone is hiding out. There is a thin "scum" on the surface that is just visible. A sample of that this afternoon came up with thousands of moving creatures. They are comfortably visible at 100X and distinctly discernible shapes at 400X.

They are milling around patches of what I would assume to be bacteria that are mostly oval pairs and about the same size.

Loose under the glass cover were about a dozen or so much bigger guys that seem to be following a herding/feeding pattern on the smaller ones.

Now that I have managed to keep these guys alive and growing I think I will consider looking around for a video camera and adapter to record this activity. It is rather amazing to watch.

More later, dinner fixin' time.