Spider skeleton II

Yes folks, today we continue the exciting saga of the spider skeleton . . . If you missed episode one you can read it here.

Clouded Marble left a comment on the last installment asking whether it was maybe a “real” dead spider and not just the skin left behind after moulting. Being a scientist, I left no stone unturned in my quest to get an answer to her (very valid) question. In this case “no stone unturned” meant emailing The Spider Club the photograph and asking for their expert opinion.

The same day (on a Sunday!) I had an email back again. These Spider Club people are very keen in their efforts regarding educating people about spiders. And they never just give a “yes” or “no” type answer – there are always a lot of interesting facts attached as well. So here is what Joan Faiola from The Spider Club says (and it is worth reading, as she gives details on how they do it) :

It certainly looks like a discarded skin, or exuvium, which is the correct term, of a female rain spider. Of course, I would have liked to see the other side of the skin, which should show the split in the carapace (head section) from which the spider escapes its old skin. The process is called ecdysis, but calling it moulting is also OK. Moulting takes place on a moulting thread for modern spiders. Baboon spiders lie on their backs to moult.

Ecdysis is necessary for growth, which only occurs during the moult. In the early days of a spider’s life, just after hatching, spiders moult every few days. Large spiders such as baboon spider females will continue to moult throughout their lives. Spiders are very vulnerable both during the process and for a while afterwards until the cuticle has hardened.

If a spider has previously shed a leg (this process is called autotomy), the moulting process allows it to regenerate its missing leg, which is usually shorter and thinner than usual, but grows to full size again over subsequent moults. The process is voluntary on the part of the spider.

A modern spider?! The term conjures up images of some old fashioned spiders who aren’t following the trends! I suspect though that that is not what she meant. I knew it was a rain spider, but was delighted that Joan could identify it as a female rain spider just from its skin. Luckily, I had “rescued” the spider skin from the garden because I thought the Spider Club people might need more photos from different angles. I say “luckily” because it rained last night and the skin would just have been a soggy mess this morning if I’d left it where it was. So here is one of the close-ups which I emailed to Joan. Looks quite scary this big!

Spider skin (exuvium) - click on photo to enlarge!

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Categories: Nature/Environment


I live on the Southern coast of South Africa, and write about the things that interest, amuse or inspire me. You can find me at https://notesfromafrica.wordpress.com and http://southerncape.wordpress.com (my photoblog)


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19 Comments on “Spider skeleton II”

  1. February 14, 2011 at 8:47 am #

    When I read the first post, I wondered if you would keep the skeleton! I probably would have and done exactly the same thing. Great close up of your “modern” spider! 🙂

    • February 14, 2011 at 8:53 am #

      I took this just zoomed in on the normal camera setting. When I tried the macro and super-macro modes I kept getting my or the camera’s shadow in the shot. Think it worked okay for the purposes I wanted it for. Still have a lot to learn about photography!

  2. February 14, 2011 at 8:50 am #

    Ohhh! Wow! Now that was fascinating, Lisa. Well done on saving the spider’s skin… 🙂

  3. February 14, 2011 at 9:25 am #

    very interesting Lisa – thank you. I would love to know more about the moult being voluntary?

    • February 14, 2011 at 9:52 am #

      I think what she means is that the spider decides when to moult. It obviously has to to grow, but it can pick the time and place.

  4. Sarita Botha
    February 14, 2011 at 9:29 am #

    Even though I’m not a big fan of spiders, I found the articles very interesting. Thanks.

  5. February 14, 2011 at 10:24 am #

    I had a nightmare about rain spiders last night. Now I remember why 🙂

  6. February 14, 2011 at 2:54 pm #

    Absolutely fascinating, Lisa! I too would have saved the skin. Happy Valentine’s day, my friend! Hope you and Willy have a lovely day!

  7. Estie
    February 14, 2011 at 6:37 pm #

    Very interesting. I have to admit that I am not mad about spiders.

    • February 15, 2011 at 6:07 am #

      I find spiders interesting, just as long as they don’t get too close!

  8. bagnidilucca
    February 14, 2011 at 9:35 pm #

    Thanks for the follow up. I find spiders fascinating.

    • February 15, 2011 at 6:11 am #

      Thanks for your comment! I never quite know how my “obsessions” are going down with my readers. Although judging by the number of hits I got on these two posts, I’d say they find them “read-worthy”. Or at least are intrigued by the titles.

  9. February 17, 2011 at 3:05 pm #

    Fascinating! I love the intricacy of the post thread, the paths that spread out from a single discovery at the end of your drive. And I learned a great deal about a process that I was totally unaware of as I followed. Thanks!

    • February 17, 2011 at 3:50 pm #

      Hi Julian! Thanks for visiting my blog and also for your comment.

      I pretty much post as I come across things myself. I’m new to watching spiders, so I’m learning a lot too. I was wondering afterwards whether I shouldn’t have waited until I had all my information together and then written a more organized single post.


  1. Wanna see a rain spider’s skin after it’s moulted? « Grains of Sand - February 14, 2011

    […] Spider Skeleton Part II Aaaah! Spider!!! […]

  2. A correction and a question | notes from africa - February 15, 2011

    […] The Suggestion Box ← Spider skeleton II […]

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