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Photo#1013751
Marbled Orb Weaver, araneus marmoreus - Araneus marmoreus - female

Marbled Orb Weaver, araneus marmoreus - Araneus marmoreus - Female
Ivydale (Big Otter), West Virginia, USA
October 25, 2014
Size: body, 1/2 inch
This is the first time I've ever seen this beautiful spider. Browsing has led me to believe it's a Marbled Orb Weaver, and I would like to confirm that and share the image. I assume it's a female because of the size. While focusing I noted that the round protruberances on her back were pulsating. Are these respiratory?

Moved
Moved from ID Request.
The pulsing is likely from the spider's heart beating.

:)
Yes! You are correct. And I can see why you are excited. I find these very cool due to there coloration. This is a beautiful specimen. Excellent work! :)
I've noticed the pulsating as well. I believe it is a defense mechanism. Yes, I know I sound like Spider man, lol, but that's the impression I get.
When these spiders spot me, they start pulsating. It could be that they are trying to produce silk so that they can 'web' away from me.
But as I origionally said, I think it's just a defense mechanism. Perhaps to make them look larger to predators.

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