Where spiders come from?

I know, a lot of us sometimes are scared of spiders. It’s even got it’s own diagnostic name: Arachnophobia. What I find incredible is the estimate that between 3 to 6% of population has a fear of spiders.. and we are not counting all the other insects. And sometimes, when we don’t fear insects; we are disgusted with them. It pains me a lot when I meet a stereotype – and this is indeed one. So here I am; about to show you the most adorable spiders. Yes; spider babies.

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What better way to capture fear of spiders but to read “Little Miss Muffet”

The pursuit started by the desire to image cell division in the field; with no other aid but just a foldscope. I was looking for eggs I can find easily (and teach anyone to find) and something that is transparent enough through the process of first stages of development. Something that is found almost anywhere in the world – and I ended up with spiders. Since, I have posted in detail on watching spider eggs develop – I just reference this post here. https://microcosmos.foldscope.com/?p=7792

But; what happens when the eggs hatch. This post is about exactly that. I had a ziplock bag with many many eggs (possibly a hundred eggs) that I kept in confinement and observed the little guys develop over time. It was the most joyful of videos and I can’t tell you how much I loved watching these guys. It’s incredible how these little machines started walking and pumping hemolymph and all the little pumps inside the legs started turning on. The skin; that was almost featureless started developing hairs and some features you expect of adult spiders (hairy beats). Here is a brief list of observations I made:

1. The surface of the spider is smooth, and only slowly do the hair cells start developing. No pigment or coloration is visible initially; but only at a later stage does any coloration become visible. This is also when internal anatomy of spiders becomes difficult to image.
2. What I find remarkable is the fact that when the spiders hatch; the legs are folded on top of the head. How do I know this; because the legs make a mark on the head. Watch carefully in the video and you will see these specific marks on the top of the head. It’s incredible that these are just depressions of the developing legs.
3. When you watch carefully; you can see little pumps everywhere in the body of the spider – pumping hemolymph. With an angular illumination from a table lamp; I was able to highlight these speckles from the blood flow going in and out of the legs.
4. Coming on to the legs; from the very start – a 5th pair of “legs” is visible. But wait – you always were told spiders have “4 pairs” of legs. That is right; the fifth pair is called “Chelicera“or jaws. Sometimes they might also contain fangs or finger or scissor like appendages.
5. In the last bit of the video; you can see spinnerets have developed. These are organs that spit out the silk. I was curious to see what is the earliest stage that they are capable of spinning webs or generate any spider silk. I could not follow them too late (somehow my bag of spiders was misplaced – I am curious where it went 🙂

Watch the video over and over again and you can make many more observations of your own. Please leave them in comments below and I will add them to this list. If you image some baby spiders; please share them with me by leaving a comment as well.

Anyway, just like as I always say – you can read about all kinds of things. But what is more fun is to watch it yourself. So; get out and catch some spider eggs. Share these adorable beings with your friends – specially who are scared of spiders. Who knows, maybe these little guys will become an internet sensation – like the kittens who currently rule the inter webs.

Never stop exploring..

cheers
manu

2 Comments Add yours

  1. Aatish says:

    Hi Manu, Great video. I have a few basic questions about this: do you leave the eggs on the slide and then let them hatch and watch them over days? Or do you take a different sample each time? And if it’s the same egg, how does it stay alive on the slide.. are there any particular tricks to doing that? I notice your slide has a circle in it.. is that like a well for putting stuff in?

  2. Manu says:

    @Aatish: I just saw your question; here are a few answers..

    1) Spiders are incredible; and they are very resilient and survive even when trapped in small places with very little oxygen over long periods of time (I have a post coming up about that sometime soon).. so yes, you can leave eggs inside the slide and let them develop (as long as they have some moisture). If you have very little moisture; after the first 10 hours or so – the eggs will undergo buckling due to evaporation. See post on the same here: https://microcosmos.foldscope.com/?p=7792

    2) Since I had more than 100 or so spiders (I still have them alive even till today); I had the luxury of taking them out from time to time from the zip lock bag I kept them in.

    3) The most important aspect of keeping things alive inside the slide is not to “squish them” while keeping them confined. Just double triple the thickness of the double sided tape; or sometimes I also use “clay” posts at the corners of the cover slips. This allows me to make a variable thickness chamber. Its crucial to use cover slips and glass slides if you want to get beautiful data and care about resolution.

    4) I just made a slide using a circle – for things that are much thicker and need more space. This can still be done with double sided tape; but it would take many pieces of tape. I took a piece of acrylic and laser cut a circular hole (you can just drill a simple hole or just cut with a hot wire or blade. I glued a cover slip on the bottom side; and I seal with a cover slip from the top; making a sealed and closed thick chamber. I can keep things alive in these chambers for much longer.

    Tell me if you found some termites in Delhi; I would love to see if you could dissect the guts and see inside..

    cheers
    manu

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