Now you can! I saw that I can easily visualize the hearts beating in my baby spiders.
It made me think of those Pro-Life Across America billboards that show a picture of a cute baby and declare “My heart began to beat at 18 days!”, as if that was a significant event. So I take it anti-choicers who see this video will forever after be kind to spiders?
This is absolutely awesome. Kudos, PZ.
The white patches seem to move independently from the pigmentation on the outer skin. What’s going on there? Are those coloring on the internal organs? Does the abdomen have a multi-layered integument? I’m reminded somewhat of the mirror spiders, (Thwaitesia argentiopunctata) with patches of reflective material that can stretch and shrink. Is it a similar mechanism to that?
PZ Myers says
The white patches are more pigment spots. Their cuticle is covered with a patchwork mosaic of different colored spots.
That is an amazing sight! I had no idea that spider hearts are on the dorsal side. The photography is very well done, as is the title.
Beating spider hearts is just enough info to spur curiosity and clicking through.
So when Samwise stabbed Shelob from below with Sting he missed the heart?
@blf, yep, got her in the ovary instead.
Someone needs to adopt Gwen the homeless tarantula. https://www.boston.com/news/local-news/2021/01/12/gwen-tarantula-adoption-mspca-angell
WMDKitty -- Survivor says
Am I the only one hearing the beat?
Only before they hatch.
bcw bcw says
Thanks to all these spider posts Facebook is putting jumping spider pages on my dash. Well at least jumping spiders are cute!
Is the video in real time? That seems WAY too slow to be a heartbeat of a creature that is only a few mm in length.
I finished the video and saw the graph of spider heart rates. Why does their heart beat so slow?
Back in the lab where I did my first thesis another student developed a way to measure heart frequencies and water loss of spiders under different environmental conditions (temperature, humidity). To measure the heart frequencies he glued some metal needle on the opisthosoma of a spider fixed in a chamber which was equipped with a sender and a receiver for radio waves. The opisthosoma shrinks and widens with every heart beat thereby inducing regular disturbances of the electromagnetic field which he recorded digitally (I was still using endless paper writers back then). Unfortunately, his results have never been published. However, the thesis titled “Messung der Wasserdampfabgabe einer einzelnen Buchlunge bei der Vogelspinne Phormictopus spp. (Araneae, Theraphosidae)” may still be available in the library of the Institute of Zoology of the Christian-Albrechts-Universiät zu Kiel (Germany)
Arachnids uber alles.
BTW, their distant relatives the millipeds are able to do periodic swarming; to be specific, the Japanese rail milipedes appear ro swarm every 8 years, which seems a peculiar period. If you want to avoid predators synchronising their cycles with the pray you typically need an odd number like 11 or 17.
Anton Mates says
@17 The Japanese millipedes don’t really need to do that AFAIK, because they have effective chemical defenses; predators don’t try to gorge on the swarms anyway. Whereas cicadas ain’t nothing but tasty, so they have extra-strong selection pressures favoring the prime number trick.
Is the heartbeat visible because they are so young or can you see it in adults as well?