A really big (and lousy) louse -- Images added

Cactusdave · Post by **Cactusdave** » Fri Dec 02, 2011 2:03 am

At last it’s time to reveal to the world the biggest and most beautiful louse I’ve ever had the good fortune to come across. Even for those who don’t share my enthusiasm for all things lousy should be impressed by this positive ‘dragon’ of the louse world. The beast is approximately 4mm in length and the slide is by Charles Collins Junior who made and sold slides under the name ‘Micro-naturalist’ in the late 1800s. The louse is described as coming from a Bengal Vulture, now a rare and threatened species of bird. I do not know anything about the classification of the louse and would be interested to hear from anyone who can help in that respect. The musculature of the louse is very well preserved, so it makes a very interesting and attractive subject for polarised light, both with and without a ¼ wave plate.

I took three sets of pictures of this subject to try to do it justice. All pictures were taken on a Nikon Diaphot inverted microscope with LWD
0.55 Phase/DIC condenser. Polarisation was achieved by removing upper and lower Wollaston prisms from the light path, while leaving polariser, analyser and variable ¼ wave plate in. All pictures were taken with a Canon EOS 40D mounted at the front SLR port. There is an in-microscope magnification factor of X2.5. First I did a simple overview using polarisation with ¼ wave plate with a Zeiss X4 Planapochromat objective which works well with this LWD condenser. The image is a composite of 12 individual images with Microsoft ICE.

There is a large version of this image which can be zoomed and panned around here. http://photosynth.net/view.aspx?cid=0c6 ... 35d201cf8f

Here is a 'head and shoulders' crop from the first image.

Next I made large 'stack and stitch' images using a Nikon X10 Plan DIC objective, using both DIC and simple polarisation. The DIC image took 1529 in 48 stacks to give the coverage I wanted and the polarisation image 965 images in 44 stacks. I will put these images and crops from them in this thread over the next day or so, but it seems too much (and too many images!

) for a single post.

Mitch640 · Post by **Mitch640** » Fri Dec 02, 2011 2:52 am

I don't think I'll ever get over the fact that muscles can survive for well over 100 years, and that they can be shown in a photograph. Is there any information left on how they actually preserved them?

A lot of work Dave, but well worth it. Maybe your images will be seen by others 200 years from now.

Tesselator · Post by **Tesselator** » Fri Dec 02, 2011 2:55 am

Very cool! Nice explanatory test too - much appreciated!

Cactusdave · Post by **Cactusdave** » Fri Dec 02, 2011 5:43 am

Thanks Mitch and Tesselator.
Mitch -- One of the chief enemies of the preservation of organic tissue is oxygen. I guess those louse muscles embedded in Canada balsam are just about as as effectively shielded from oxygen as they would be in a vacuum. Think how beautifully the soft tissues of insects are preserved in amber, it's the same effect.

My next project was to image the entire louse with the X10 objective and simple polarisation without the 1/4 wave plate, to really bring up the muscle structures. 954 images in total in 44 stacks. Stacked with Helicon Focus, stitched with Microsoft ICE. This is the result:

A link to a large zoomable and pannable version is here, http://photosynth.net/view.aspx?cid=570 ... 2363b0c9ad This is a 344 megapixel image and can be deeply zoomed into before the resolution goes.

Some crops reveal the muscle detail nicely. First the head:

Now a leg joint. I love the way you can see the muscles attached to the joint in the back leg.

This is a detail of the longitudinal musculature of the abdominal segments. I am really pleased with the resolution here. I guess the overlaying granular structures are eggs. The are present over much of the abdomen and laying eggs must be a pretty big preoccupation if you are a louse

Anyway that's my image limit for today so more tomorrow.

Mitch640 · Post by **Mitch640** » Fri Dec 02, 2011 5:49 am

Wow, these are awesome. I can't believe how sharp the muscles are still defined.

Cyclops · Post by **Cyclops** » Fri Dec 02, 2011 11:54 am

Incredible photos!!

Cactusdave · Post by **Cactusdave** » Fri Dec 02, 2011 12:27 pm

Thanks Mitch and Cyclops. The DIC result is good too I think, but you'll have to wait to judge that.

lauriek · Post by **lauriek** » Fri Dec 02, 2011 1:10 pm

Wes · Post by **Wes** » Fri Dec 02, 2011 2:28 pm

Very impressive images. Thank you for posting.

Sounds like you put a lot of effort to produce them. Good job!

Cactusdave · Post by **Cactusdave** » Sat Dec 03, 2011 1:19 am

Thanks Laurie and bromodomain.

Last of the straight polarisation pictures before I move on to DIC. This is the 'rear end' of the louse. I guess we are seeing the anus and the complex of muscles involved in expelling waste.

Cactusdave · Post by **Cactusdave** » Sat Dec 03, 2011 2:16 am

Finally a series of images taken using DIC with the Nikon X10 Plan DIC objective. A total of 1529 images in 48 stacks were used to create this image.
It's interesting to compare this image with the polarising image. Purely for resolving and displaying muscles, the polarising image is better. It renders the rest of the body mostly transparent, allowing the muscles to shine through clearly. The DIC image on the other hand, displays great detail in the head and legs, but the body shows one of the limitations of this technique. There is just too much complexity in the depth stacks to fully display in a 2D image. Darker structures overlying lighter structures also act to obscure them in the stack output. Nevertheless the overall result is pleasing, and I felt it was worth the effort.

A large version that can be zoomed and panned is here: http://photosynth.net/view.aspx?cid=af4 ... 1ed0de8ca0

A few crops from the DIC image. First the head:

A really tight crop into the 'nostril'. I'm sure its not a nostril functionally, but it certainly looks like one

. You can see the muscles better in this tight head crop.

This image shows the legs in detail. Here where complexity is comparatively limited across the depth of the stacks, the muscles show up very nicely.

A last crop of the front limb joints and the adjacent body structure.

Mitch640 · Post by **Mitch640** » Sat Dec 03, 2011 4:21 am

I think you would need SEM to see any more detail. I am amazed.

ChrisR · Post by **ChrisR** » Sat Dec 03, 2011 5:16 am

I'm not a microscopist, but these look extraordinarily wondrous to me.

arturoag75 · Post by **arturoag75** » Sat Dec 03, 2011 7:14 am

superb details!
arturo

RogelioMoreno · Post by **RogelioMoreno** » Sat Dec 03, 2011 8:10 am

Very nice! Thank you for sharing.

Rogelio