Spinnerets of the Orb Web Weaving Spiders – Silk Tubes

[Walter Piorkowski]

Please follow the silk strand to the apex of the two lower spinnerets to see a dozen or so individual silk strands emanating from the silk tubes.



Top image:
Horizontal FOV 2.5mm
Canon 10D
Canon 20mm macro @ f/5.6 on extension tubes
Series of 50 images @ .001 inch increments
Diffused dual fiber optic illumination
Combine ZM, Photoshop

Bottom Image: An enlarged crop of upper image
Horizontal FOV 1.25mm
Combine ZM, Photoshop


Sometime back I posted an image of the spinnerets of a crab spider. That spider was not a web builder so I felt compelled to see what difference there would be in a true web-building spider. Three members of the spider family Araneidae were collected. This post shows a subject from the subfamily Araneinae that I decided to show separate from the others due to my good fortune. This subject kept its drag line attached allowing me to expose the face of two of the spinnerets and their silk tubes.

I am delighted that I was able, in this image, to catch the silk coming out of the tubes. I have always been fascinated by the rate at which a spider can produce a drag line. I now have a better understanding of how the silk strand is produced.

I am not normally one to enlarge an existing image preferring to get closer buy changing the optical arrangement but the subject made that impossible. Two more spinnerets will following the next post.

Walt

[rjlittlefield]

Excellent work, Walt! I can hardly wait to see the next post.

BTW, there's no shame in a crop, if it really does expose more detail as it seems to here.

--Rik

[beetleman]

Excellent detail Walter. They sort of look like little rotory brushes designed to keep the silk in a ball shape ?

[Bruce Williams]

Fascinating posting Walt - a real eye opener! I knew that spiders produced different types of silk but had no idea that any of it was produced in such a complex manner.

One of those postings that supports the old adage about a picture being worth a thousand words....(or 10,000 words if you go with the Chinese proverb ).

Bruce

[Ken Ramos]

A very nice set of informative images here Walt. You're really a brave guy getting that close to a spiders behind or just getting close to spiders for that matter, even though I did poke at one with my finger only a few days ago to make it get from behind a flower so that I could get a shot of it.

[Walter Piorkowski]

Thank you gentlemen for your comments. Doug mentioned the white ball shape in the center of the 4 spinnerets. I don’t know what this was meant to be, but I don’t believe it is part of the strand manufacturing process.

As Bruce stated there are different types of silks. For example, this spider can produce a sticky or nonstick version used separately in different parts of the same web! I am so impressed with the nature’s ability to provide such a primitive creature with such control as to be able to shut off and turn on different silk tube spigots at the proper time to produce such results. So much to study and learn about this planet and its inhabitants, so little time.

And Ken sounds like the brave one to me! My fingers are not part of the collection process.

Walt

[rjlittlefield]

I have been looking at the rear ends of a couple of spiders this evening, and I am really impressed by how much information there is in these photos!

Having a bit of dragline still attached to these spinnerets is incredibly helpful.

Thanks, Walt!

--Rik

PS. Walt, I'm not so sure about that "primitive" idea. Remember, that spider has just as long an evolutionary history as we do!

[Walter Piorkowski]

Thanks for bringing up this old image for review. I'm glad it provided you with additional info. On the primitive point, spiders probably have been around longer than us. I saw a fosillized impression Saturday. Anyway, my intent was their instinct vs our gray matter. Hope to be posting again soon.

Walt

[Mike B in OKlahoma]

I am flabbergasted....WOW!!!! This is very impressive work.