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Harvestman

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maquaii
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23 Sep 2011, 1:34 pm

Anyone familiar with these critters? Found one right behind my chair a little while ago, and i can't say i understood what was going on, it was like he had gotten all his legs twisted up. Figured maybe it's new skin and it got stuck on it? So i tried to "free" it's legs, but it curled back together and continued to look as if he was struggling. Couldn't help myself imagining that it suddenly got a rewiring of his brain and couldn't tell which leg was which, up on leg 6 was down on leg 2 :P I was amazed over how flexible the legs were, the tips curled in on themselves. Makes me wonder how that works. (Gotta google that)
But yeah, anyone familiar with such behavior in arachnid?


Ah well, threw him out.



Oh and hur durrr... =3
Image



Last edited by maquaii on 23 Sep 2011, 1:46 pm, edited 1 time in total.

Vigilans
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23 Sep 2011, 1:41 pm

Most of the time when I mention Harvestmen people have no idea what I'm talking about. "Daddy Long Legs" is unfortunately how most people know these things. :lol:


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Jory
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23 Sep 2011, 1:49 pm

Yeah, I had to look this up. "Oh, it's a Daddy Long Legs." Apparently these things aren't technically spiders. Which is kind of like the fact that Antarctica is technically a desert. These things are less terrifying than regular spiders, but they still set off my arachnophobia and make me want to napalm them all.



maquaii
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23 Sep 2011, 1:52 pm

We call them "vevkjerring", direct translation i think would be something like Weaving-hag. Hehe, but most people here seem to think they are spiders.



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23 Sep 2011, 1:54 pm

You can tell they aren't spiders just from their body, they only have one segment


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maquaii
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23 Sep 2011, 1:58 pm

There are two segments, it's just that they are so close together that it appears as one. But as a kid we learned that spiders were different because they had 8 legs, so i suppose thats why people consider them to be spiders. "Different, 8 legs must be a spider."



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23 Sep 2011, 9:46 pm

Here is how there legs work:

Quote:
he legs consist of coxa, trochanter, femur, patella, tibia, metatarsus, tarsus and claw. In most Eupnoi and many Dyspnoi the coxae are freely movable, while in others they are fused together and immovably attached to the underside of the body. In contrast to spiders, hydraulic pressure plays no significant role in leg movement. However, a flexed leg of Leiobunum returned 80% of its energy by extending. This springlike property is caused by sclerites that span across the joints, which probably consist of resilin.

While the metatarsus is undivided, the tarsus can consist of three to over one hundred tarsomeres. In most Cyphophthalmi the tarsus is entirely undivided. Many long-legged forms in the superfamily Phalangioidea can wrap their tarsi two or three times around twigs. Nevertheless the tarsi contain no muscles, but only tendons of the claw muscles. These muscles originate in the patella, tibia and metatarsus. Most harvestman legs have only one claw, but in Grassatores, the later two pairs of legs end in two claws, where an additional structure can even give the appearance of three claws.

Nymphal stages of Grassatores and some Insidiatores feature additional structures on the latter two pairs of tarsi, which probably allow adhesion to smooth surfaces during molting, as they are not present in adults.

Legs of Eupnoi and many long-legged Dyspnoi are weak at the base of the femora. When legs are trapped or caught by a predator, these harvestman can detach the restrained leg by a powerful movement of the coxa-trochanter joint. The detached legs of Phalangioidea can twitch for several minutes, with oxygen provided by spiracles in the tibia. The pacemaker neurons responsible for this become active when they lose the connection to the central nervous system. Each of the two twitching leg joints contains an independent pacemaker. Even immature harvestmen cannot regenerate lost legs.

One reason for the hanging stance characteristic for long-legged harvestmen seems to be enhanced stability on exposed surfaces, for example against wind. Leiobunum vittatum (and probably other harvestmen) walks by lifting the "central" (counting the second pair as antennae) leg of one side and the outer legs of the other side forward while the other three rest on the ground (alternating tripod gait, similar to that of insects).[1]

http://en.wikipedia.org/wiki/Harvestman_anatomy


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23 Sep 2011, 10:53 pm

I clicked on this thinking it was going to be about a creepy urban legend like the Slender Man, but being afraid of spiders, I found something much worse. :pale:



maquaii
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24 Sep 2011, 12:33 am

While walking out on my porch yesterday evening to "say goodnight" to the cats i feed, i remembered that i basically laced my room with bug poison, but that was at least 2 months ago. It must still be effective... So basically i was bothering a harvestman in agony. I feel slightly like a sociopath now.

As i got back to my bedroom, and was about to undress, i was thinking that the harvestman must have taken a ride on my pants (they are long and i shuffle) after wandering around the porch feeding the cats. But as i was thinking that, something was moving down the sleeve of my sweater... Theheh..
I don't know if it fell down on my as i walked out, or if i got it from one of the cats as i held them. Either way, a harvestman was taking a stroll down my arm.
I had to laugh a little...



maquaii
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24 Sep 2011, 12:34 am

Titangeek wrote:
Here is how there legs work:

Quote:
he legs consist of coxa, trochanter, femur, patella, tibia, metatarsus, tarsus and claw. In most Eupnoi and many Dyspnoi the coxae are freely movable, while in others they are fused together and immovably attached to the underside of the body. In contrast to spiders, hydraulic pressure plays no significant role in leg movement. However, a flexed leg of Leiobunum returned 80% of its energy by extending. This springlike property is caused by sclerites that span across the joints, which probably consist of resilin.

While the metatarsus is undivided, the tarsus can consist of three to over one hundred tarsomeres. In most Cyphophthalmi the tarsus is entirely undivided. Many long-legged forms in the superfamily Phalangioidea can wrap their tarsi two or three times around twigs. Nevertheless the tarsi contain no muscles, but only tendons of the claw muscles. These muscles originate in the patella, tibia and metatarsus. Most harvestman legs have only one claw, but in Grassatores, the later two pairs of legs end in two claws, where an additional structure can even give the appearance of three claws.

Nymphal stages of Grassatores and some Insidiatores feature additional structures on the latter two pairs of tarsi, which probably allow adhesion to smooth surfaces during molting, as they are not present in adults.

Legs of Eupnoi and many long-legged Dyspnoi are weak at the base of the femora. When legs are trapped or caught by a predator, these harvestman can detach the restrained leg by a powerful movement of the coxa-trochanter joint. The detached legs of Phalangioidea can twitch for several minutes, with oxygen provided by spiracles in the tibia. The pacemaker neurons responsible for this become active when they lose the connection to the central nervous system. Each of the two twitching leg joints contains an independent pacemaker. Even immature harvestmen cannot regenerate lost legs.

One reason for the hanging stance characteristic for long-legged harvestmen seems to be enhanced stability on exposed surfaces, for example against wind. Leiobunum vittatum (and probably other harvestmen) walks by lifting the "central" (counting the second pair as antennae) leg of one side and the outer legs of the other side forward while the other three rest on the ground (alternating tripod gait, similar to that of insects).[1]

http://en.wikipedia.org/wiki/Harvestman_anatomy


Yeah i looked it up as i wrote the first post, but thank you!