Amoenba gluttony...

While  looking through some old water that I was going to toss I found an amoeba chowing down on a  rather long filamentous algae, likely one of the cyanobacteria. Although a valiant effort was made to down (surround) the hapless meal, common sense finally prevailed and the meal was ejected...no worse the wear. I took a few photos that capture the attempted ingestion.

Here was my first look at the attempted ingestion

Moving along...

Not sure this will work...

The meal has been disgorged

Predator and prey in harmony

I also found another couple of amoeba in the water drop.

And another...

And this neat looking diatom (I think)

Fishing at Willow Creek

This post was supposed to feature unbelievable fishing exploits accompanied by photos of huge fish (in my other blog) and a smiling angler. Luckily I brought along a few specimen bottles so I didn't go home entirely empty-handed. Sometimes it pays to have two great hobbies.












The algae samples from willow creek held a number of diatom species that I wasn't familiar with. Not that I'm familiar with diatoms, it's just that the shapes and sizes of these were different than I was used to as a fledgling biologist. Here is one of the longer ones, about 150 microns long.

Here is a nicely patterned one.

And perhaps the empty frustule of a similar one.

A Closterium desmid. These are actually quite interesting in that they have little moving bodies in both tips. These are crystals that are powered via Brownian movement and are supposedly used to tell them which end is up.

Another Closterium Desmid.

One of those amoeba with radial arms. This is the first one in which I've seen a pseudopod extending from the body, if that's what it really is. I'm now getting a little confused...might this be a centroheliozoan? The radial arms would suggest so, the pseudopod points to an amoeba. Anybody know what this is?








 
Here is a picture of a Phacus, one of the Euglenids. This is a gorgeous creature in life and can be quite graceful in exploring it's drop of water. It's hard to describe what it actually looks like...it bears a certain resemblance to a 3 bladed arrowhead if you know what that looks like.









Here is another view of the same individual, this time showing the flagella. These little guys move forward at the flagella end and spin gracefully along their path.

More ditch dwellers...

I feel somewhat like the coachman flogging his dead horse since the images I post seldom portray the details I encounter through the eyepiece. I'm going to put up this last set of pictures and wait until my camera adapter is set properly before posting more images. Unless of course something terribly interesting unfolds beneath my objective.

 I had been looking at these circles for some time, unable to figure out what they were. Well, yesterday after staring at one for a while I noticed some movement on the periphery and...Ahah! Pseudopods...and I had myself another amoeba. This one looks like a member of the Genus Arcella, perhaps Arcella hemisphaerica. It was neat to finally figure out this was an amoeba.

I found this specimen with the amoeba completely out of it's test (shell). It was alive and was moving, eventually raising the test and slowly starting to move under it. I moved on to other explorations before it's move was complete but my hope is that it found its way back into the house.

Another amoeba, no idea what this type is other than it seems to be one of the "naked" versions.

And might this be even another one?

A different one with a better view of the rays. Or is it a different type?

This diatom frustule had a somewhat different shape than most of the other ones I had seen... usually pennate so I snapped a picture.

 I had been following gastrotrichs around for a while trying valiantly to get a picture, to no avail. These critter are fast and elusive, preferring to slow down only when covered by detritus. Anyway, I did manage this shot as a souvenir of my nonproductive pursuit.

An unidentified ciliate.

Another.

A flagellate.

Another?

Alga?

Objectives 101

I'm barely out of Kindergarten on this subject myself so this one is for the raw newbies. I going to try to frame this in the way I would have liked to see it presented 6 months ago. Since my microscope is an older 160 mm T.L. Zeiss, most of my information applies mainly to that microscope. However each of the other "big four" follow a similar format.

Objectives are the heart of the microscope and likely the most important component in delivering a good image to the eyepiece or camera sensor. Objectives are built up with differently shaped lenses and usually the more glass, the better the image. Let's look at why that is. Lenses have three fundamental problems:

1. Different wave lengths of light (different colors) focus at different points out from the lens with red light being the furthest away and violet being the closest. This happens because each color has a slightly different refractive index and thus comes out of the back of the lens at a different angle. Of course white light includes all the colors between red and violet so your depth of focus is spread out rather than at a point, which is what we want. This is called Chromatic aberration and is generally corrected for to some degree in even the cheapest lenses.

2. Light rays coming to focus from the outer edge of the lens do so at a different spot than those coming through the center. This is called Spherical aberration and can be corrected, but at a cost.

3. A flat image projected through a lens will result in a slightly curved image. This results in uneven focus across the face of the image. For example, the center of the field can be in focus while the outer edge is slightly blurry. This can be fixed, again at a cost.

The least expensive lenses are the Achromats or Achromatic objectives. These are corrected for two colors; red and blue and also corrected for spherical aberration for the color green.These are OK for viewing but not so good for photography. If you must take a picture, best results can be obtained using a green filter and viewing the prints in B&W.

Next up are Planachromats or just plain Plan objectives. These are corrected similarly to the achromats with additional correction to create a flat field. These are the minimum that should be considered for photography.

The Neofluars, sometimes called semiapochromatic, are another step up. These lenses have flourite  elements and are corrected for 3 colors but not for flatness of field. Many are used for photography but are appropriately cropped to exclude the unfocused areas.

The cream of the crop are the Planapochromats (or planapos) and these are corrected for everything but unfortunately are subject to delamination, at least for some brands. So, eBay buyer beware. These lenses also enjoy the highest NA figures so are best if resolution is a primary goal.

And what type of microscope should you be aiming these objectives for, given that you want to study pond water? Least attractive is brightfield but with oblique illumination you can enhance contrast quite a bit, perhaps enough to enjoy the hobby. But in my mind the minimum you want to look at is Phase contrast and if you can afford it...DIC is the gift from the gods when it comes to viewing and photographing phase objects.

That's it for now. Hopefully I haven't lead you astray and this little explanation will lead to further study. After these basic considerations there is the whole subject of how they are to be used, lit, aligned, etc. Google can again be your friend.

Denizens of the Ditch

Rotifer Cafeteria

I found a few more lively things in the ditch beside my home and snapped a few pictures. On the camera adapter front, things look a bit promising. The fellow who sold me the scope is working on adapting a Leitz relay lens to my Canon. This would allow the use of a Zeiss objective and, hopefully (with fingers crossed), would result in crisper images. But I digress.

This little fellow was worm-like and seemed to run across my view on front and back legs. A look through all my "critter" guidebooks seemed to indicate this was a larva of some type of Diptera, a two-winged fly. Closest picture looked like a Tendipes.

This is one of those no-idea-what-it-is ciliates. It was surrounded by what appeared to be cilia and if I remember correctly, moved fairly slowly. I'm tempted to call it a Silliate but that wouldn't be very scientific.

This is likely some alga in the act of dividing or multiplying, or whatever it is they do in trying to take over the world. Or could it be a set of designer spectacles that a tardigarde happened to lose?

This is one of those colonial flagellates commonly found in ponds; this one has 32 members (I counted them). Each individual has a couple of flagella that help propel the organism around the slide. I'm not certain but this may be a Pandorina.

I found what appears to be a Cyclops larva without ever seeing any large egg sacks on the female cyclops which are plentiful in my water samples. I've only observed what seems to be the start of these egg sacks. This little guy was very active until the water evaporated enough, with help from some tissue paper, to somewhat hinder his exuberance. A couple of red eye spots are visible on the front of his head.

Another one of those "Hmmmm???" critters. Very likely a Euglenid but I have no idea beyond that. I'm looking forward to the day when I can start getting closer to some level of recognition.



That's it for this session. Fishing season starts this Saturday and, unless we are inundated with continuously bad weather, I anticipate my postings will be somewhat diminished. Until later then.

Rotifer video and other odds and sods

The yard is again blanketed in snow, temperatures near freezing and I'm questioning why my father chose to stop here on his way to settle in the Gulf Islands. Although I remain dubious, some are suggesting summer may actually arrive this year. At least I had the foresight to gather some specimens after a too short balmy interlude. So let's take a look at what my intrusion into the freezing waters of a roadside ditch actually uncovered. No image because it was zooming but I saw my first Gastrotrich. Pretty cool little creature and very distinctive. And a bunch of other stuff!

This appears to be an ostracod, a bi-valve that feeds on detritus...at least that's where I found them. I saw a number of different sizes but they all seemed to look alike. I found one "dead" individual but it seemed just like an empty shell with the outline of the innards inside. Although it seems unlikely, I wonder if they molt? Then again, that would account for all the different sizes.

I saw only a few diatoms but I think this is a new one to me...not the usual pennate diatoms.

This might be a type of flagellate colony and unfortunately I couldn't see any detail beyond what is shown in the image. What I did observe was that water was being pulled towards it, very similar to what a rotifer or vorticella might do. The whole bunch was only about 10 microns across.

A ciliate, possibly a hypotrich but I may be getting beyond my abilities here. Kind of neat anyway and a new one for me. :)

Another ciliate, again possibly a hypotrich. Again, I may be wrong.

Not sure what I have here, perhaps a flagellate or a planktonic alga, perhaps a Micractinium. Or perhaps not.

No idea here but it did look different.

I think I've seen one of these before but am still as unsure as I was before about its identity.

A couple of flagellates that were swimming around rather slowly may be Euglena.

Another unknown ciliate, perhaps another hypotrich. There appear to be cirri, fused cilia that act as one unit, both anteriorly and posteriorly. Are these last two utterances even words?