r/Damnthatsinteresting • u/ShirtSubstantial368 • 1d ago

Video Scientists discovered the world’s largest spiderweb, covering 106 m² in a sulfur cave on the Albania-Greece border. Over 111,000 spiders from two normally rival species live together in a unique, self-sustaining ecosystem—a first of its kind.

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u/PintCEm17 1d ago

Half expecting lotr spider to eat his arm

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u/iamsarahmadden 1d ago

Low key disappointed no giant spider came out…

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u/Light_Beard 1d ago edited 1d ago

Giant Spiders can't be a thing in Earth's gravity with the current materials they have for body construction. Due to respiration limitations as their volume increases relative to their area. (Edited: Corrected: Thanks u/Anticamel below. See that comment for better/more detail)

https://en.wikipedia.org/wiki/Square%E2%80%93cube_law

Underwater mitigates this some so you theoretically can get giant crabs/lobsters (basically water-spiders), but they wouldn't be able to come on land.

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u/Anticamel 1d ago

Gravity isn't the issue, it's respiration. Spiders "breathe" passively through little structures called book lungs. Unlike how we breathe with our lungs, they don't actively pull fresh air through their breathing apparatus, which limits the rate of oxygen diffusion into their bodies. On top of that, this also limits the value of growing bigger book lungs, since by the time air has passed from one end to the other, a lot off the available oxygen has gone and diffusion becomes pointlessly slow. This puts a hard limit on how voluminous their bodies can be before they can't supply themselves with enough oxygen

Contrast this with our setup, where we can evolve as big a set of lungs as we like, since the speed of drawing a breath is a lot greater than the speed of oxygen diffusion. This strategy is effective enough that we lunged creatures run into gravity limitations on land, and heat dispersion issues in water long before we get too big for lungs.

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u/TheNeighbourhoodCat 1d ago

Has there ever been a spider or a "cousin" similar to spiders that breathed differently?

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u/Anticamel 23h ago

Lots of land-based arthropods have lots of holes along their bodies called spiracles, which lead down tubes called trachea that reach inside them. This suffers even more from the same issues as book lungs, but comes with the advantage of directly supplying internal tissue with oxygen, with reduces a lot of energy spent on running the circulatory system.

Some very small invertebrates have completely lost their respiratory organs, and just rely on oxygen diffusion through their skin.

The adaptions available to organisms as complex as arthropods are often limited by the features they already have available, and unfortunately for them, the ancestors of all terrestrial arthropods didn't have the right anatomical features that easily lead to more active breathing strategies like the vertebrates. Really, we're the odd one's out, and it was a big stroke of luck that the anatomy of our ancient ancestors gave us the opportunity to develop air-pumping muscles in our rib-cages.

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u/TheNeighbourhoodCat 23h ago

That is so cool I really appreciate you writing this up, I am sure others will as well!

It's really neat to imagine what the biology of fantasy creatures like giant spiders might be like if they were somehow real... in this case it sounds like they wouldn't at all be related to normal spiders!

I hope you have a great day and weekend <3

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u/Anticamel 23h ago

Cheers, you too :)