Spiders No.25 – Tarsal Claws of a Funnel Web Weaver.

[Walter Piorkowski]

Leitz Ortholux microscope
4X Leitz projection eyepiece plus 1/3x relay lens

Image No.1, One of two paired superior claws.
113 images at 1 micron increments
Image cropped
Leitz UO 23X Apochromat, ULTROPAK objective
Diffused Fiber Optic Illumination

Image No.2. Middle claw used to grasp the silk strands.
Approximately 40 selected images from image number 1, 1 micron increments.
Image cropped
Leitz UO 23X Apochromat, ULTROPAK objective
Diffused Fiber Optic Illumination

Image No.3. Different angle to show both superior claws.
197 images at 1 micron increments
Image cropped
Leitz UO 23X Apochromat, ULTROPAK objective
Diffused Fiber Optic Illumination

Image No.4. End of tarsus leg segment showing all 3 claws.
85 images at 5 micron increments
Image cropped
Nikon 10X Achromat,
Diffused Fiber Optic Illumination

Canon 50D
Zerene and Photoshop processing.

All spiders have claws at the ends of their legs. Web building spiders all have three claws and use the middle claw to grasp the silk strands. Non web builders have two claws. Another single claw is sometimes also found at the tip of the palpi.

In this post I present my best results of a most challenging subject, the three tarsal claws of the spider family Agelenidea, a web builder. The small size, number of thick surrounding hairs and the almost total obscuration of the third middle claw, made clear images very difficult. I did not want to falsify the subject by removing or trimming the hairs, so I worked out different orientations and alternative methods.

I found that sectioning out portions of a deep stack would reveal, although somewhat less sharp, internal details. This method was used in image number two to reveal details of the silk grasping claw.

Walt

[Charles Krebs]

Walter,

Superb images.

[ChrisR]

Superb set, Walt.
Edit - no I hadn't seen Charllie's adjective!

[Mitch640]

Beautiful images and great work, yes. But then I think about what I know from sitting and watching spiders work on a warm summer day.

So let me see if I have this right. A human, with a 3.5 pound brain has 4 appendages, 2 arms and 2 legs, each having 5 digits for a total of 20 and couldn't walk on a rope if he had to. A spider has 8 legs with 3 digits for a total of 24 and can run and jump on a thread, fight and kill, all at blinding speeds and never miss a step, all with a brain that has maybe a couple thousand cells.

Remind me, who is superior?

[Pau]

Remind me, who is superior?

To do a spider way of life, spiders are much better adapted, but for an human life style humans are the best
In Biology the terms superior and inferior (altough with a long history of use in the scientific literature) have little to none sense

Walt, excellent pictures again, both beautiful and documentary.

[Mitch640]

altough with a long history of use in the scientific literature

Thanks Pau, for putting that in perspective. Being told how superior we are, by people who [at one time] had earned respect for supposedly knowing the difference, has done a lot of damage, and not only to their respect. It's like my first 40 years was a waste of time. We would all be better off to constantly question everything from every source.

[Walter Piorkowski]

Charles, Chris, Mitch and Pau. I am so happpy you all enjoyed these images. I wasn't sure how they would be recieved.

Mitch, don't forget about those amazing trapeze artists walking on their high ropes. I do agree with you on how amazing spiders are, especially after seeing the third, middle claw and how small it is. For the spider to reach out and catch the silk strand with that single appendage is a tribute to how its sensing mechanisms can guide its movements.
Walt