Giant Spiders (question)

[Max]

I have a question, how big could a spider get (potentially) and still be able to effectively hunt (specifically humans) and not die from its size? I read somewhere that house cat sized spiders would spell doom for humans. I don't know if this should be in testing or not.

[Kanastrous]

Goliath Tarantulas - the world's largest spiders - are about a foot across. There's your apparent upper size limit (for modern spiders, anyway).

[Kanastrous]

Goliath Tarantulas - the world's largest spiders - are about a foot across. There's your apparent upper size limit (for modern spiders, anyway).

[Dooey Jo]

I read somewhere that house cat sized spiders would spell doom for humans.

Why would it? Humans would be 10 times bigger than the spiders, so it's really unlikely they'd hunt humans for food. Unless they hunt in groups, I suppose, but then you might as well imagine many, small, really poisonous spiders. Like in that film with that big screaming spider...

[Max]

I read somewhere that house cat sized spiders would spell doom for humans.

Why would it? Humans would be 10 times bigger than the spiders, so it's really unlikely they'd hunt humans for food. Unless they hunt in groups, I suppose, but then you might as well imagine many, small, really poisonous spiders. Like in that film with that big screaming spider...

I wish I could find the source that made the statement. I'm assuming that a spider the size of a cat (body wise, not leg span wise) would still have all the tools and abilities that allows it to capture prey at a smaller size. I don't know if their speed would increase, but I'm assuming their web strength would for example. Maybe they would have to be bigger, I don't know, that's why I asked. What would be the upper theoretical physical/mechanical limitations before a spider is incapacitated by its own weight, and would humans become prey at that limit?

[Max]

*EDIT*

I'm assuming that a spider the size of a cat (body wise, not leg span wise) would still have all the tools and abilities that allows it to capture prey compared to itself at a smaller size.

[Omeganian]

http://www.stardestroyer.net/Empire/Science/Size.html

[Johonebesus]

It isn't possible for a spider to big enough take down a human under normal conditions with size alone. If it's big enough a fang might be able to puncture an artery in just the right scenario, but the same is true of house cats. The main limit, as I understand it, is respiration, not weight. Since they draw oxygen passively from the air, they can only get so big before the air passages aren't efficient enough to supply their needs. Even in the carboniferous terrestrial bugs weren't drastically bigger, in terms of mass, than living record holders.

[Ghost Rider]

http://www.stardestroyer.net/Empire/Science/Size.html

And instead of being a fucking lazy idiot, you could have read the topic at hand instead of assuming he wanted a 50ft tall spider.

[CaptainChewbacca]

Mike's topic also talks about the relative weakness of a man-sized spider, and the subject matter pretty handily applies to this thread, Ghost Rider.

[Kanastrous]

Mike's topic also talks about the relative weakness of a man-sized spider, and the subject matter pretty handily applies to this thread, Ghost Rider.

Don't spoil Ghost Rider's fun; he lives for that stuff.

ducks incoming bitch-smack

[Max]

It isn't possible for a spider to big enough take down a human under normal conditions with size alone. If it's big enough a fang might be able to puncture an artery in just the right scenario, but the same is true of house cats. The main limit, as I understand it, is respiration, not weight. Since they draw oxygen passively from the air, they can only get so big before the air passages aren't efficient enough to supply their needs. Even in the carboniferous terrestrial bugs weren't drastically bigger, in terms of mass, than living record holders.

I'm not familiar with spider anatomy, but wouldn't it be possible for them to adapt in some way to compensate for that? Or is physically impossible without changing the physiology so much that it's no longer classified as a spider and becomes something completely different altogether?

[Kanastrous]

If you breathe through spiricles, you're pretty well limited by the inflow-outflow the apertues provide. Get big enough, and your inner tissues stop getting enough oxygen.

[Master of Ossus]

I'm not familiar with spider anatomy, but wouldn't it be possible for them to adapt in some way to compensate for that? Or is physically impossible without changing the physiology so much that it's no longer classified as a spider and becomes something completely different altogether?

It would have to develop an entirely new respiratory system that would be unique among insects, since insects simply aren't that efficient at breathing.

I think it would probably need a brand new circulatory system, too, but I'm not sure on that count.

[Rahvin]

I have a question, how big could a spider get (potentially) and still be able to effectively hunt (specifically humans) and not die from its size? I read somewhere that house cat sized spiders would spell doom for humans. I don't know if this should be in testing or not.

While a cat-sized spider will reduce me to a blubbering, screaming child (followed by a murderous rampage as soon as I find an extremely large shoe), how exactly would even a very large spider "spell doom for humans?"

There are many predators on Earth that are perfectly able to kill a human...and yet our species seems to be doing pretty well.

Larger size could imply a larger venom dosage and possibly the ability to spin thicker silk. But despite the strength of spider silk it would need to be a lot thicker to be able to effectively stop something the size of an adult human being, and a larger venom dosage per bite isn't any more dangerous than any of the predators that can take us down without venom at all.

Even if a large spider could make a more effective predator against humans, what prevents us from shooting the damned things, or even just swinging a baseball bat? A cat-sized spider will still go splat.

One of the reasons some modern spiders are even dangerous at all is because of their ability to hide. When you see a cat-sized spider in the corner of your garage where a black widow would be virtually invisible, you aren't sticking your hand up there to be bitten.

Finally, spiders don't usually attack humans. They defend themselves against us. We are not their preferred prey, and it's not just because of our size. With a few exceptions (I hear the funnelweb will chase you, a terrifying concept), spiders don't seem to liek the way we taste and would much rather wait around for a more tasty, easier meal to come along. I don't see how size would change that.

[Ghost Rider]

Mike's topic also talks about the relative weakness of a man-sized spider, and the subject matter pretty handily applies to this thread, Ghost Rider.

Don't spoil Ghost Rider's fun; he lives for that stuff.

ducks incoming bitch-smack

I see both the retards don't get the difference between actually explaining shit versus linking an entire page. But hey, spam away, morons

[Kanastrous]

*shrug*

I've explained stuff.

But I wouldn't expect you to let that stand in the way of your fun.

[Bladed_Crescent]

If you breathe through spiricles, you're pretty well limited by the inflow-outflow the apertues provide. Get big enough, and your inner tissues stop getting enough oxygen.

It would have to develop an entirely new respiratory system that would be unique among insects, since insects simply aren't that efficient at breathing.

I think it would probably need a brand new circulatory system, too, but I'm not sure on that count.

Spiders don't just rely on spiracles for respiration, though; many species have primitive 'book lungs' that they use in conjunction with, or as a replacement for, their tracheole system. This system is made up of many hollow plates (hence "book"), through which blood passes for gas exchange.

How well these book lungs would scale up into a cat-sized spider is an answer I don't have; just noting that spiders (and scorpions) don't have the same respiratory system as insects.

[Jaepheth]

I wish I could find the source that made the statement...

The only place I've ever heard that was a line from one of the characters in the movie Arachnid.

[Shroom Man 777]

Jesus Christ!



I really suggest that if you want spiders that hunt people, you should go for not-as-large species that behave socially. There are some species of social spiders...

Now maybe you could make a fictitious species of social spiders that just spin HUEG webs. But when mating season, or spawning season, comes - they start migrating like a swarm of army ants - but with spiders! And spiderlings!

Ten thousand spider bites, killing you, and then they cocoon you and start sucking away at your precious bodily fluids! While you are still alive!

[Superman]

I've had a total of two pet tarantulas when I was a kid. One thing that's always amazed me about them, and I suspect this goes for the Goliath spiders as well, is that they're basically harmless. A bite from a Black Widow or Brown Recluse is probably ten times more dangerous. Tarantulas look like something out of a horror movie, but they don't often move particularly fast (I know they can, but they usually don't), their venom is relatively weak, and they're pretty damn fragile. One good fall from a few feet can split them open. I know that someone is about to explain that this makes sense from an evolutionary standpoint (you can see the same with scorpions), but I've always found it interesting.

[Rye]

A cat-sized spider would presumably pose as much threat to humans as a cat-sized cat. Maybe a snake if it retained its human-hurting venom.

[petesampras]

A cat-sized spider would presumably pose as much threat to humans as a cat-sized cat. Maybe a snake if it retained its human-hurting venom.

Surely Spiders have very low muscle mass compared with a cat? They would hence have nowhere near the speed and agility.

[petesampras]

A cat-sized spider would presumably pose as much threat to humans as a cat-sized cat. Maybe a snake if it retained its human-hurting venom.

Surely Spiders have very low muscle mass compared with a cat? They would hence have nowhere near the speed and agility.

By muscle mass I should have said muscle mass proportional to overall mass.

[Dooey Jo]

They also extend their legs by filling them with fluid (their muscles only retract the legs), which might be a problem if they grow too large. Either they have to increase their blood pressure, or they'll have to move slower (which they must do anyway since they get heavier).