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Video of spider heart beating - real?

by Newai
Tags: beating, heart, real, spider, video
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Newai
#1
Oct10-10, 12:41 PM
P: 107


Seems like it is faked, but I dunno. BTW, the uploader explained that the noise in the background is a howler monkey and you'll hear the guy making a howling sound back early in the video. Sounds strange, but anyway.

That's the spider's exoskeleton. I am having trouble believing this.
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MysticDude
#2
Oct10-10, 04:37 PM
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Looks pretty legit, but with all the special effects we have today, the guy could have just been expanding it on a program.

Fake or not, if I was there and I saw that thing out of nowhere, you wouldn't see me there in 5 seconds because I would be running away. If I found the spider first, then I would examine it, but if that spider came out of nowhere, then I would get scared so badly lol.
mugaliens
#3
Oct11-10, 02:24 PM
P: 595
I'm familiar with either that or a similar, Florida-inhabiting species. It's exoskeleton appears to be cracked. If you'll look here, you'll see a spider's heart exists directly beneath the location where the exoskeleton was moving back and forth.

MysticDude
#4
Oct11-10, 07:53 PM
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Video of spider heart beating - real?

Quote Quote by mugaliens View Post
I'm familiar with either that or a similar, Florida-inhabiting species. It's exoskeleton appears to be cracked. If you'll look here, you'll see a spider's heart exists directly beneath the location where the exoskeleton was moving back and forth.
That is awesome. You said that it appears to be cracked, does that mean that it is just some sort of illusion? I'm not a fan of spiders but the way that that one looks, it's just awesome lulz :P
Ivan Seeking
#5
Oct11-10, 10:26 PM
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I was going to show you all how silly this is by noting the typical heart rate of a spider. Surely a spider has a very fast beat! But I guess the joke's on me.

Heart rate in spiders: influence of body size and foraging energetics
JE Carrel and RD Heathcote

Resting heart rates in 18 species of spiders as determined by a cool laser transillumination technique range from 9 to 125 beats per minute. Cardiac frequencies obtained in this fashion may readily serve as a measure of standard rates of metabolism. A spider's resting heart rate is a function of body size and of foraging energetics...
http://www.sciencemag.org/cgi/conten...t/193/4248/148

Still, there is nothing directly indicating that we are seeing a heart beat.

Since there is no way to verify the authenticity of the video, the only way to resolve this is for someone to find a proper reference describing what is seen.
Borek
#6
Oct12-10, 05:00 AM
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There is always a possibility that video is not edited, just the pulsation is not a beating heart. No idea what it could be, but there are so many fancy things in animal kingdom you don't have to fake anything to surprise the audience.
mugaliens
#7
Oct12-10, 10:46 AM
P: 595
Quote Quote by MysticDude View Post
That is awesome. You said that it appears to be cracked, does that mean that it is just some sort of illusion? I'm not a fan of spiders but the way that that one looks, it's just awesome lulz :P
I've seen many of these spiders up close. I've never observed any of them with a separation in the shell as depicted in the video. Doesn't mean they don't, but...

Is there an entomologist in the house?
Newai
#8
Oct12-10, 05:12 PM
P: 107
The guy who made the video claims to be a "Zoologist specializing in insects and arachnids." He describes himself in his blog as "a wandering biologist/ linguist/ ethnographer/ storyteller." His channel at YouTube: http://www.youtube.com/user/memutic

He has a ton of videos all devoted to educating people about creepy critters with these short overviews. He doesn't seem like the sort who would kill such a reputation. But I dunno.
Lichtbrandung
#9
Nov10-10, 02:08 AM
P: 1
Quote Quote by mugaliens View Post
I'm familiar with either that or a similar, Florida-inhabiting species. It's exoskeleton appears to be cracked.
Mhh, it doesn't seem cracked to me. Looks pretty regular. Intact. Besides, this would be a somewhat unusual part for a crack to occur. Still you're perfectly right in pointing to the fact that this kind of pulsation is not normally seen in this, or in fact in any other spider species. Therefore I propose the following solution to the "mystery". As this really is quite a handsome Gasteracantha cancriformis female, I'd say it's that handsome not least because it's just gotten a nice new "costume". In other words, I think, not too long before the video was shot, this spider must've molted. Now, when a spider (or, indeed, any arthropod) molts, it sheds its old exoskeleton, or cuticle, and thereby unveils the new one which has grown just beneath the old one. But when this happens, the substance (mostly chitin) of the new cuticle is not at once fully solidified. It slowly hardens, and gets firm again, once being exposed to the air, though that takes a while. Until then it's fairly smooth (and not a good protection at all). This, in all probability, is what explains why here we can actually sneak a peek at those vital functions going on just beneath the abdominal exoskeleton, which, in these stages, is and behaves rather like a skin.

Quote Quote by Ivan Seeking View Post
Still, there is nothing directly indicating that we are seeing a heart beat.
It, really, is its "heartbeat". Though a spider's heart is more like a mere main artery, or a simple (yet thicker, and muscular in order to contract) continuation of the aorta, if you like. It's a channel, or tube, with tiny slits in its sides, which can be shut by valves, called ostia. They're open when the "heart" relaxes, so blood can practically be sucked in -- mainly not out of vessels, but just out of the surrounding tissue. After that, the tube will contract, thus closing the ostia (or pores), keeping the blood in, constraining it and then pressing it forward. So it's essentially a channel-valve-system and not so unlike our own hearts, yet.. different. What we witness in the video, obviously, are simply these very contractions of the central hemocoel. That is, well, the spider's "pulse", or heartbeat...
Nikitin
#10
Jan1-11, 05:54 PM
P: 627
jesus that thing is nasty
PhysicsHigh
#11
Jan2-11, 05:33 PM
P: 70
Quote Quote by Nikitin View Post
jesus that thing is nasty
What is that yellow thing? It looks like armor lol. :(
SpeedOfDark
#12
Jan19-11, 12:00 AM
P: 54
Yeah that's an arachnid, if anyone could show me a spider with an exoskeleton I would be very happy to see that.
Nikitin
#13
Jan19-11, 06:47 AM
P: 627
Quote Quote by PhysicsHigh View Post
What is that yellow thing? It looks like armor lol. :(
I believe it is there to keep people like us away.

PS. I haven't had biology class in a long time, so I wonder why did only poisonous creatures develop scary-colours? I would expect that any creature which is often hunted would somehow develop such "warning colours" (as the ones who did not would die off)? Maybe it has something to do with location?
Borek
#14
Jan19-11, 07:17 AM
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Quote Quote by Nikitin View Post
I wonder why did only poisonous creatures develop scary-colours?
Nothing to wonder, as the assumption is wrong. Google "Red on yellow, kill a fellow; red on black, friend of Jack".
ajclarke
#15
Jan19-11, 07:55 AM
P: 35
I was under the impression many animals developed bright colours just as a warning, regardless of their poison properties or lack of them.

Either way, I wouldn't have my camera that close to it. I'd be miles away
Newai
#16
Jan19-11, 06:10 PM
P: 107
Quote Quote by SpeedOfDark View Post
Yeah that's an arachnid, if anyone could show me a spider with an exoskeleton I would be very happy to see that.
You don't have to look far; spiders have exoskeletons.
SpeedOfDark
#17
Jan19-11, 06:37 PM
P: 54
Quote Quote by Newai View Post
You don't have to look far; spiders have exoskeletons.
I recant my statement I have ABSOLUTELY NO IDEA what i was thinking when I said that, I don't think this is a spider though it does look to be an arachnid.
Newai
#18
Jan22-11, 03:32 PM
P: 107
Quote Quote by SpeedOfDark View Post
I recant my statement I have ABSOLUTELY NO IDEA what i was thinking when I said that, I don't think this is a spider though it does look to be an arachnid.
Lichtbrandung identified it earlier in the thread.

Quote Quote by Wikipedia
Gasteracantha cancriformis (the crab spider, spiny-backed orbweaver, spiny orbweaver spider, crab-like orbweaver spider, crab-like spiny orbweaver spider, jewel spider, spiny-bellied orbweaver, jewel box spider or smiley face spider) is a species of spider.
http://en.wikipedia.org/wiki/Gasteracantha_cancriformis


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