SPIDERS No.35 – Spinnerets Part 3 - Spigots Emitting Silk

Images made through a microscope. All subject types.

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Walter Piorkowski
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Location: South Beloit, Ill

SPIDERS No.35 – Spinnerets Part 3 - Spigots Emitting Silk

Post by Walter Piorkowski »

Image

Image

Image

Image

Image No.1 (Horizontal field of view 0.22mm)
Image of a small portion of a posterior lateral spinneret showing silk spigots. A total of 4 of the spigots visible are emitting a single strand of silk. Follow each strand back to its source spigot to see each of them. This image is a 50% crop of the original frame.
Reflected diffused fiber-optic illumination.
136 images at .5 micron increments, Nikon 40xW Achromat


Image No.2 (Horizontal field of view 0.22mm)
Same region of that seen in Image 1 but a single image focused on the tip of the emitting spigot center left. Two other silk strand are visible in portion to the center and right. This image is also a 50% crop of the original frame.
Reflected fiber-optic illumination.
1 single image, Nikon 40xW Achromat
.

Image No.3 (Horizontal field of view 0.34mm)
Deep stack of a small portion of a posterior lateral spinneret showing a “field” of silk spigots. Un-cropped image. Although difficult to see, there are two spigots with silk strands still attached amongst the multitude. The image comes nowhere near what a SEM shows but it is fun to make some comparisons.
Reflected diffused fiber-optic illumination.
392 images at .5 micron increments, Nikon 40xW Achromat


Image No.4 (Horizontal field of view 0.34mm)
A shorter stack of a small portion of a posterior lateral spinneret showing a single spigot clearly releasing a silk strand. An additional silk strand appears to be lying on the spinneret surface unattached to any spigot. Un-cropped image.
Reflected diffused fiber-optic plus EPI illumination.
50 images at .5 micron increments, Nikon 40xW Achromat

Leitz Ortholux microscope
4X Leitz projection eyepiece plus 1/3x relay lens
Canon 50D
Zerene PMax and/or DMap stacking.
Processing in Photoshop and Bibble Pro 5.



Thanks for looking at my final set of images in this spinneret series. My goal has been achieved. Although it was the original goal of this study (see Part 1 and 2), I never found silk during that phase. I was unaware that any silk was present until the higher magnification and resolution of the 40x objective provided fleeting glimpses of silk as seen in Image #2. I was very taken by the similarity that I was seeing, as I focused in and out, to SEM images showing silk strands still attached. Unfortunately the stacking software cannot produce an image like a SEM but the evidence is there. Look up the SEM work of Dennis Kunkel to see how much more amazing a SEM image can be.

I have roughly measured the silk strand leaving the spigot at approximately 2.5 microns. How many individual spigots would be producing silk as this orb web weaving spider creates the “strand”, that we actually see with our naked eye, could number a thousand or more.

Mitch, now you can see that when strand production is in full swing on a living subject many hundreds of these individual strands are what is needed to create the result we see with the naked eye. And it is my understanding that different glands produce different kinds of silk based on the application. Amazing!!!

Walt

Pau
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Post by Pau »

Great! =D>
Pau

rjlittlefield
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Post by rjlittlefield »

Walt, this is spectacular work. Very nicely done, to say the least! I eagerly await that SEM in your spare room, but in the meantime, this optical stuff is working quite nicely!

SEM's have their own limitations, of course. Your earlier photos of the spider eyes would have been impossible by SEM, since the SEM would show only the surface of the cornea.

--Rik

PS: To save other folks the challenge of searching, a couple of Dennis Kunkel's images showing spinnerets with silk are HERE and HERE.

Mitch640
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Joined: Sun Aug 15, 2010 1:43 pm

Post by Mitch640 »

A great finale to a wonderful series.

Earlier, I was thinking those points coming out of the dimple, were strands of silk. But now I see the points are the actual spigots and the silk comes from the end of the point.

I am still curious to know how she starts the silk and how she grabs the first strands. And to think, they know how to do this at such an early age. :)

Walter Piorkowski
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Location: South Beloit, Ill

Post by Walter Piorkowski »

Thank you Gentlemen!

Rik. In Part #3 I pushed the software and my microscope to its practical limits for this type of subject matter. So maybe its time to move on to find a SEM on EBay. Only joking! I did not know that the SEM only showed surface details. Very interesting. Thanks so much for putting in those Kunkel links.

Mitch. Wonderful to read that you are learning along with me. For some reason I am driven to produce an educational type series.
Regarding your question. My personal observations on live subjects under 10 to 20x magnification is that not only the abdomen, but the spinneret complex is highly maneuverable. My subjects will simply touch the spinnerets to a surface, immediately anchoring it and then either pull away the body or begin drawing out a continuous strand with the legs. It could be that simple tactile contact causes the glands to immediately start discharging silk.

Walt

Mitch640
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Joined: Sun Aug 15, 2010 1:43 pm

Post by Mitch640 »

You have to admit, it is a subject worth learning more about. I keep coming up with more questions though, every time I look at these images. Like, how closely do spider spinnerets resemble those of other spider species, and other species that spin silk, like caterpillars? And what and why did the first silk spinneret develop in the first place? Just so many questions. How could a person possibly get bored? :)

RogelioMoreno
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Post by RogelioMoreno »

Wow, amazing!

Rogelio

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