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  Topic: Spider Silk, from the bathroom wall< Next Oldest | Next Newest >  
Lou FCD



Posts: 5455
Joined: Jan. 2006

(Permalink) Posted: June 28 2006,02:10   

Well regardless of opinions about coddling or crucifying every theist in sight, I think this post by Lenny deserves to see the light of day in some place other than The Bathroom Wall:

Quote
Getting back to the subject, it should perhaps be pointed out that spider silk didn't originally evolve for making webs.  The group of arthropods from whcih spiders may (or may not have) evolved, the trigonotarbids, didn't have any spinnerets and presumably didn't have any silk.  One of the earliest known spiders, Attercopus, at 380 million years, did. Of course, one of the defining characteristics of spiders is that they have spinnerets.

Some of the most primitive of the existing spiders are the mygalomorphs, the group that includes the tarantulas.  Some living species of tarantula-like spiders still have segmented apparent in their abdomens, and they are probably very similar to the most primitive of spiders.  This group goes back to 300 million years in the fossil record.  And although they have spinnerets and produce silk, they don't make webs.  Their silk is used largely to make eggsacs, and to line the burrows that they live in.  A few species of trapdoor spiders use silklen lines to make a radiating pattern with their burrow at the center, which alerts them to passing prey.  It seems likely that prey-catching webs were a (much) later modification of that strategy.

There are also arboreal species of tarantula, which live in silken shelters that they spin high up in trees.  They too, however, don't make webs.  It seems a good likelihood that they adapted to an arboreal lifestyle in order to avoid monsoon rains which flooded their terrestrial burrows, and it seems likely that the modern orb-weaving spiders began with a similar lifestyle.


Spiders fascinate me, always have.

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“Why do creationists have such a hard time with commas?

Linky“. ~ Steve Story, Legend

   
Renier



Posts: 276
Joined: Jan. 2006

(Permalink) Posted: June 28 2006,02:32   

Silk worms of course also have silk (as does other worms). Now, it's a stupid question, but is this trait a seperate evolution path from spiders? I would think so.

Interesting, but here we call the tarantulas "baboon spiders". All in all, we have 3 dangerous spiders here, the worst being a light (beige) little spider with a dark mouth area and dark feet tips. Called a "Sakspinnekop".

There is also a very interesting spider called a "Roman". Red hunting spider. I read somewhere that they are closer related to scorpians than other spiders. It's mouth is totally different from other spiders and it has no venom. It will however kill a scorpian in "combat". They also have the habit of running from shade area to shade area, thus creating the impression they are chasing humans (running after moving shade). Girls don't like them :)

  
Stephen Elliott



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Joined: Oct. 2005

(Permalink) Posted: June 28 2006,02:36   

Quote (Lou FCD @ June 28 2006,07:10)
Spiders fascinate me, always have.

Spiders scare me. Well sometimes they do. Funny thing is, I don't mind them when camping.

  
Lou FCD



Posts: 5455
Joined: Jan. 2006

(Permalink) Posted: June 28 2006,02:48   

Quote (Renier @ June 28 2006,07:32)
Silk worms of course also have silk (as does other worms). Now, it's a stupid question, but is this trait a seperate evolution path from spiders? I would think so.

Interesting, but here we call the tarantulas "baboon spiders". All in all, we have 3 dangerous spiders here, the worst being a light (beige) little spider with a dark mouth area and dark feet tips. Called a "Sakspinnekop".

There is also a very interesting spider called a "Roman". Red hunting spider. I read somewhere that they are closer related to scorpians than other spiders. It's mouth is totally different from other spiders and it has no venom. It will however kill a scorpian in "combat". They also have the habit of running from shade area to shade area, thus creating the impression they are chasing humans (running after moving shade). Girls don't like them :)

See this is good stuff.

I've been repeating the mantra since I was a kid that ALL spiders are poisonous, it's just that most spiders' bites aren't terribly harmful to HUMANS.  I've always been surprised at how many people I've met that think that there are about three poisonous spiders in the whole world, usually:

1. The Black Widow
2. The Brown Recluse
3. The dreaded Tarantula

Now I have to revise my statement.  I was seriously not aware that there were any spiders without venom.  I'll have to spend some time checking that guy out.

One of my favorite sports as a young fella' was chasing girls and making them squeal.  (Ok, that's still one of my favorite sports, but ummm... different.)  Any spider that gives the impression of chasing girls all by itself is pretty cool in my book.   :D

--------------
“Why do creationists have such a hard time with commas?

Linky“. ~ Steve Story, Legend

   
Renier



Posts: 276
Joined: Jan. 2006

(Permalink) Posted: June 28 2006,03:02   

Lou, I'll see what I can dig up over the "strange" Roman spider.

Our 3 "bed guy" spiders is
1) Sakspinnekop. I'll try and find the english name
2) Black Widow - I have one in my garage door...
3) Violin Spider.

The Tarantula spyders don't rate as dangerous over here. About a year ago, met one in my garden. Nice hairy fellow. Scientific name ended with "Lightfooti" and I think they only live here in the Cape Town region. The article stated they are very good jumbers and can give a bit of a nasty bite as Tarantulas go.

  
Renier



Posts: 276
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(Permalink) Posted: June 28 2006,03:07   

Ok big boys, brace yourself... Red Roman Spider....

Mr Jaws

  
Renier



Posts: 276
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(Permalink) Posted: June 28 2006,03:15   

Oh look. Turns out they are not spiders after all...

good site with photos

  
Chris Hyland



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(Permalink) Posted: June 28 2006,03:29   

Looks like camel spiders.

  
Lou FCD



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Joined: Jan. 2006

(Permalink) Posted: June 28 2006,03:30   

From the link you provided:

Quote
Male solifugids have hook-like flagella on the chelicerae


I wonder if that means they are irreducibly complex and intelligently designed?

Quote
They run their prey down and once they catch it they eat while the prey is still alive with vigorous ripping and cutting actions of the powerful jaws.


Nasty!

--------------
“Why do creationists have such a hard time with commas?

Linky“. ~ Steve Story, Legend

   
Renier



Posts: 276
Joined: Jan. 2006

(Permalink) Posted: June 28 2006,03:34   

Quote
Sicarius  hahnii from the Northern Cape and Namibia is possibly the most lethal spider in the world. Fortunately, due to its habitat, it is rarely encountered and appears reluctant to bite. I have often scooped up a Sicarius by hand while looking for reptiles. This spider should not be handled, as there is no effective treatment.


From this site

I forgot to mention the six eyes crab spider as another dangerous bloke, but people VERY seldom encounter them.

It also metions it is a very "old spider" and silk is only used for the egg sacs.

Then, the "sakspinnekop"...
Here

Enjoy!!!

  
Lou FCD



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Joined: Jan. 2006

(Permalink) Posted: June 28 2006,03:36   

Oh, and to clarify,

IIRC violin spider is a common name for the brown recluse, because of the violin shaped dark spot on it's back.

Samey same.

--------------
“Why do creationists have such a hard time with commas?

Linky“. ~ Steve Story, Legend

   
Lou FCD



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(Permalink) Posted: June 28 2006,03:39   

I stand corrected.  Your violin spider looks different than our violin spider.

--------------
“Why do creationists have such a hard time with commas?

Linky“. ~ Steve Story, Legend

   
Renier



Posts: 276
Joined: Jan. 2006

(Permalink) Posted: June 28 2006,03:39   

Quote
I wonder if that means they are irreducibly complex and intelligently designed?


Yeah, flagella, I also cringed when I saw that word. Please don't tell Behe, or we wil never hear the bloody end of it :) Or, you want to make some money? Write a ID book about the designed spider @ss.

  
Lou FCD



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Joined: Jan. 2006

(Permalink) Posted: June 28 2006,03:44   

Ahhh... related....

From wikipedia-

Quote
The brown recluse spider is a venomous spider, Loxosceles reclusa, of the family Sicariidae (formerly of the family Loxoscelidae). It is usually between 1/4 and 3/4 inch (6.4-19.1mm) but may grow larger. It is brown and usually has markings on the dorsal side of its thorax, with a black line coming from it that looks like a violin with the neck of the violin pointing to the rear of the spider resulting in the nickname "fiddleback spider" or "violin spider". Coloring varies from light tan to brown and the violin marking may not be visible. Since the "violin pattern" is not diagnostic, it is far more important, for purposes of identification, to examine the eyes. Contrary to most spiders, which have 8 eyes, recluse spiders have 6 eyes arranged in pairs (dyads) with one median pair and 2 lateral pairs. Only a few other spiders have 3 pairs of eyes arranged this way (e.g., scytodids), and recluses can be distinguished from these as recluse abdomens have no coloration pattern nor do their legs, which also lack spines.

The brown recluse spider is native to the United States from the southern Midwest south to the Gulf of Mexico ([1]). The native range lies roughly south of a line from southeastern Nebraska through southern Iowa, Illinois, and Indiana to southwestern Ohio. In the southern states, it is native from central Texas to western Georgia. They are generally not found west of the Rocky Mountains.

Recluse spiders, which also include Mediterranean recluse spider (Loxosceles rufescens), build irregular webs that frequently include a shelter consisting of disorderly threads. Unlike most web weavers, they leave these webs at night to hunt. People get bitten when they unintentionally squeeze them in clothing and bedding.


Got the article on Brown Recluse Spider when I searched for violin spider.

However, note from the link you provided-

Quote
Loxosceles can be grouped into cavernicolous (cave dwelling) and savannah species. One of the three cavernicolous species,  Loxosceles parrami, associated with mining areas, has been artificially introduced into Gauteng homes and is responsible for many cases of human envenomations in the area. Loxosceles is uncommon within 20 - 50 kilometres of Cape Town and bites by this spider appear to be translocations.

Violin spider (Loxosceles sp.)

Loxosceles are free ranging and nocturnal using only a few strands of silk as a retreat in caves or under rocks. Its free-ranging behaviour is what distinguishes it from the Pholcidae that are web-bound. Loxosceles are small with a body length of about 8 mm and long slender legs about 18 mm long. The carapace is relatively flat and slightly longer than wide and most species bear the characteristic dark violin-shaped marking. The cylindrical /oval abdomen is either plain or marked with light and dark patterns. In some species sand particles adhere to the cuticle but not to the same extent as Sicarius.


--------------
“Why do creationists have such a hard time with commas?

Linky“. ~ Steve Story, Legend

   
Renier



Posts: 276
Joined: Jan. 2006

(Permalink) Posted: June 28 2006,03:55   

Seems like the violin spider is a common customer over at the US and here. I know here aree some species that is only native to Namibia. The 6 eyes means they are related to the crab spider, I think. Will have to check a tree to see. Say, what other dangerous 8 legged critters you got over there? We have a bigger type of black widow here, the brown widow. Not as poisonous as the black widow, but a nasty bite...

  
Lou FCD



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Joined: Jan. 2006

(Permalink) Posted: June 28 2006,04:08   

Well there's the violin, three (I think) different species of black widow, the red widow, at least one whole genus of tarantulas I think (some of which use their legs to shoot irritating hairs at your eyes if you piss them off), scorpions, and if you count non-poisonous but disease carriers, a bunch of ticks.  PZ would probably be the one to ask for the exhaustive list.

Personally I worry more about poisonous two legged critters (read "fundies") over here, but YMMV.

--------------
“Why do creationists have such a hard time with commas?

Linky“. ~ Steve Story, Legend

   
Lou FCD



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Joined: Jan. 2006

(Permalink) Posted: June 28 2006,04:15   

Quote
New world tarantulas (those found in North and South America) are equipped with urticating hairs on their abdomen, and will almost always use these as a first line of defense. These hairs will irritate sensitive areas of the body and especially seem to target curious animals who may sniff these hairs into the mucous membranes of the nose. These hairs generally do not irritate the hands or other tough areas of skin. Some species have more effective urticating hairs than others. The goliath birdeater is one species known for it's particularly irritating urticating hairs. Old world tarantulas (from Asia) have no urticating hairs, and are more likely to attack when disturbed. Old world tarantulas often have more potent, medically significant venom.


From Wikipedia article on Tarantulas

--------------
“Why do creationists have such a hard time with commas?

Linky“. ~ Steve Story, Legend

   
Renier



Posts: 276
Joined: Jan. 2006

(Permalink) Posted: June 28 2006,04:58   

Cool trick with the hairs. Almost like the fundies when they are cornered...lol

Wonder of the tarantulas here in Southern Africa would be "old" or "new" world... I'll ask one tonight.

Cool storie. Guys in the army, fighting on the borders, used to catch scorpians, spiders and other stuff and pit fight them in ration boxes. The Red Roman spider always won the scorpians. I recall that the spider disabled the scorpian's sting first. However, the real champ was a purple kind of millipede, demolishing every foe.

  
Lou FCD



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Joined: Jan. 2006

(Permalink) Posted: June 28 2006,07:01   

Bug Wars the Movie

That's cool.  I'll keep my eyes open for the purple guy if I'm ever in your neck of the woods.  If it can kick all kinds of ass in those kinds of fights, I don't think I want it p.o.d at me.

Let me know what the tarantula tells you tonight.  I'm interested in his take on the whole old world/new world thing.

When I was in the army, we tended to put large bipedal mammals (us) into a box (bar), add alchohol (of choice) and watch them fight.  Bigger scale, same result.  The purple (most heavily bruised) guy was declared the winner in a backwards drunken logic kind of way.

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“Why do creationists have such a hard time with commas?

Linky“. ~ Steve Story, Legend

   
Henry J



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(Permalink) Posted: June 28 2006,08:57   

Re "they eat while the prey is still alive "

The velociraptor of Arthropods?

  
"Rev Dr" Lenny Flank



Posts: 2560
Joined: Feb. 2005

(Permalink) Posted: June 28 2006,13:32   

Quote (Renier @ June 28 2006,07:32)
Silk worms of course also have silk (as does other worms). Now, it's a stupid question, but is this trait a seperate evolution path from spiders? I would think so.

Interesting, but here we call the tarantulas "baboon spiders". All in all, we have 3 dangerous spiders here, the worst being a light (beige) little spider with a dark mouth area and dark feet tips. Called a "Sakspinnekop".

There is also a very interesting spider called a "Roman". Red hunting spider. I read somewhere that they are closer related to scorpians than other spiders. It's mouth is totally different from other spiders and it has no venom. It will however kill a scorpian in "combat". They also have the habit of running from shade area to shade area, thus creating the impression they are chasing humans (running after moving shade). Girls don't like them :)

(Sorry, I'm not used to this format yet . . . .)

Spiders actually have several different silks that they produce/  The silk for webs is different than that used for eggsacs or molting carpets, for instance.  And they all formed independently.


Yes, Baboon spiders is how tarantulas are referred to in Africa.  In South America, they're Bird-eating spiders.  (No, they don't really eat birds -- or baboons).  The African tarantulas are lots more aggressive (but not any more venomous) than other tarantulas.

Your "Red Roman" sounds like a solfugid, or "sun spider".  They're not really spiders.  They're not really dangerous, either, although they certainly LOOK mean.  ;>


Also, it is a common misconception that tarantulas are dangerous.  They're not.  There is no record anywhere of any human being that was killed by the toxic effects of tarantula venom (although some people have been killed because they are allergic to it, like bee stings).

I've kept a dozen species of tarantula over the years (currently a Mexican redleg, _Brachypelma smithi_), and have been bitten a couple times.  Feels like two or three  hornet stings.  (I've also been stung by a couple different scorpions, and even managed to get nailed by a South American centipede once --- THAT hurt).  I used to breed black widow spiders, and was always rather careful around them.



I wrote a book a few years back on keeping tarantulas as pets.    :>

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Renier



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(Permalink) Posted: June 28 2006,23:42   

Quote
and even managed to get nailed by a South American centipede


I said the champion in the box fight was a millipede. Sorry, meant centipede.

Lenny, I recall reading that a tarantula here in Cape Town area is the most dangerous of all (lightfooti). This only means you get a headache when they bite you :-)

We also have another big spider here that is not dangerous. It's called a "rain spider" and they do get pretty big. I'll see if I can find a photo.

Yes, the Red Roman is of the "Sun Spider" type. They do look mean. With jaws like that...*shudder*

Lou, you ever got the "purple" awards? Sounds like something we have in my reinactment group...

  
"Rev Dr" Lenny Flank



Posts: 2560
Joined: Feb. 2005

(Permalink) Posted: June 29 2006,14:20   

Quote (Renier @ June 29 2006,04:42)
Lenny, I recall reading that a tarantula here in Cape Town area is the most dangerous of all (lightfooti). This only means you get a headache when they bite you :-)

That would be _Harpactirella lightfooti_, which is pretty common in South Africa.  It is indeed one of the few tarantulas that have been reported to produce systemic symptoms (numbness, cramps, dizziness, difficulty breathing) rather than just localized pain and tissue damage.

The tarantula that is generally agreed by keepers to have the worst bite are the _Poecilotheria_ species from India and Sri Lanka.  Although nonlethal, they apparently have active neurotoxins that can produce systemic systems strong enough to put you in a hospital.  The African _Pterinochilus_ species also produces systemic symptoms, as do bites from the _Heteroscodra maculata_, _Theraphosa blondi_, and members of the _Stromatopelma_ and _Pseudotheraphosa_ genera.

But once again, no tarantula has ever killed anyone with direct toxic effects, and tarantulas are not considered to be a major emdical problem in any area of the world.

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Renier



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(Permalink) Posted: June 29 2006,20:54   

Thanks for the info Lenny.

That centipede that bit you. What type of toxins?

  
"Rev Dr" Lenny Flank



Posts: 2560
Joined: Feb. 2005

(Permalink) Posted: June 30 2006,01:11   

Quote (Renier @ June 30 2006,01:54)
Thanks for the info Lenny.

That centipede that bit you. What type of toxins?

I got tagged by a young _Scolopendra gigantea_, about four inches in length.  (The adults can reach a  foot in length.)

It made my hand swell up for a day or so, and it felt stiff and numb for a couple days after that.

Not much is actually known about 'pede venom, but they seem to contain both neurotoxins and toxins that break down tissues and cell walls, like snake venom.  'Pede venom also contains a lot of seratonin, which specifically produces pain in vertebrates.

Not an experience I'd recommend to anyone.  

I did get bitten by a flying snake _Chrysopelea ornata_ once.  Although they are rear-fanged snakes and have a hard time getting fangs in to something as big as a human, this one managed to nab me in the web of skin between my finger and my thumb.  It made my thumb go numb for half an hour or so.

And I have a scar on my left hand from a young water monitor.

I've, uh, been bitten by lots of things.   :)

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"Rev Dr" Lenny Flank



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(Permalink) Posted: June 30 2006,01:21   

Quote (Renier @ June 29 2006,04:42)
We also have another big spider here that is not dangerous. It's called a "rain spider" and they do get pretty big.

Here in Florida, our largest native spider is the golden-silk orb weaver, _Nephila clavipes_.  The spiders are two or three inches in legspan and make huge webs, six feet or so across.  But they are quite docile, and everyone freaks out when I pick them off their webs and play with them a while before putting them back.

We also have huntsman spiders here, _Heteropoda_ species, but they are imports from overseas and are not native to Florida.  People here call them "banana spiders" and are terrified of them.  They are utterly harmless, though, and I've kept several as pets.

There was a population of _Brachypelma_ tarantulas established near Ft Myers when someone released some pets, but the state conservation people eradicated them.  Florida has lots of problems with introduced non-native wildlife.

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bystander



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(Permalink) Posted: June 30 2006,01:55   

.. and don't forget the Aussie Spiders - Redbacks and Funnel Webs.

Michael

  
"Rev Dr" Lenny Flank



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Joined: Feb. 2005

(Permalink) Posted: June 30 2006,13:45   

Redbacks are the Aussie versions of the black widow.

Funnel web spiders are odd -- it's just the male that is dangerously venomous, and, apparently, only to primates.  Just a quirk of biochemistry.

Of course, the male spiders are the ones who wander around looking for females, and thus are far more likely to encounter a human.

Must have been, uh, designed that way.   ;)

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Renier



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(Permalink) Posted: July 01 2006,09:15   

Lenny, and all the other spiderma... uh, spider fans out there.

I found the rain spider here (same site as the above links)
Link here

They get prerry big, as far as spiders go. How big does that Orb Spider in Florida get? I have a couple of these "rain spiders" in my back yard.

A friend of mine kills all rain spiders in his house, by request(command) of his wife. She had a shower one evening and was toweling her back when she felt something "scratchy" between the towel and her back. hehehehehe..... Needless to say, her reaction was pretty intense.

As for handling any spider, like you plucking the orb spiders off, eh...no. It's just not me, but then, the only insects to ever zap me were wasps and bees. My father used to farm bees, and as for the wasps, well, I deserved it.

  
Renier



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Joined: Jan. 2006

(Permalink) Posted: July 01 2006,09:36   

Just a correction. It appears as if the "baboon spiders" are not actually Tarantulas. From this article here

It is however a VERY interesting article to read. It mentions that the baboon spiders are not true spiders as should be classified such as scoprians is to the spider family.

I don't know how accurate this site is, but it refers to our own local verion of "Tarantulas" as Wolf Spiders. They are very small. See Here.

  
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