Spiders and ATP-Production

[Sarah Katharina Franz]

I was wondering... Spiders often stay utterly still for a very long time, which isn't very good for the transport of oxygen, and their organs for absorbing oxygen are not very efficient from what I know. So basically, there shouldn't be a great amount of oxygen around.
But spiders can move very quickly when they feel alarmed etc.
I have heard ( in our biology lessons) that some reptiles resolve to anaerobic respiration for similar reasons, and produce lactic acid to quickly gain the energy needed for their fast movements.
Is it possible that spiders do a similar thing?
As in usually produce their energy via aerobic respiration, then switch to anaerobic respiration when alarmed or something similar?
My biology teacher didn't know anything about this, and the books I have don't go into such specific things.
I know very little about spider anatomy, and even less about their metabolism, and apologize for any big logic gaps, or mistakes I made.
Thanks for any answers!

[Colin D Wilson]

Spiders have a small groove (typically just in front of the spinnerettes, although some, i.e. Dysdera, have a pair just behind the book lungs) which convey oxygen to the interior organs, this is the tracheal spiracle.
The book lungs are situated on the sides of the abdomen, just behind the pedical, and are composed of many fine leaves (hence "book") that allow fluid flowing through them to absorb oxygen.
Mygalomorphs have two sets of book lungs (no tracheal spiracle)

Basically..efficiency of the book lungs can be determined by the fact of some fastest, more active, spiders dont have them but can have up to four tracheal spiracles instead (bearing in mind waterloss as a reason here too). typically book lungs process oxygen at a given rate, if you were to chase your spider round the room for a few minutes it would suddenly come to a complete stop, if not a state of collapse due to not being able to process oxygen quickly enough.

[Sarah Katharina Franz]

Thank you for the quick reply!
It helped me to a better understanding of how they absorb oxygen, though still a very basic one. i think I will google the things you mentioned to learn more about them.
So you think that although they could reach a point where their oxygen absorbtion doesn't meet their needs, they wouldn't go over to anaerobic respiration, but just stop moving/collapse?

[Colin D Wilson]

Sorry Sarah just realised i didn't put that in and really didn't answer your question.....

Yes they do resort to a drastically inefficient anaerobic respiration and they "process" this very quickly and then come to a complete halt
Simply... when spiders run / move quickly for any length of time they "technically" hold their breath (for want of a better term) due to body functions needed for running intefering with the functions needed for breathing (high pressure in the prosoma interferes with the circulation of hemolymph from the book lungs within the opisthosoma).
lack of oxygen and increased carbon dioxide is the end result

[Sarah Katharina Franz]

"typically book lungs process oxygen at a given rate"
why is that?
from what I gathered the spiders don't actively take in air, like a human does when he breathes, but wait for it to diffuse in, so there is only a limited amount of air available. But couldn't the amount of hämolymph passing be increased by fastening the "heartbeat", resulting in a better spreading of the oxygen? And I just read in a German Wikipedia article that the opening of the stigmata can be increased by muscle contractions...
So of course there is a limit to the amount of oxygen a spider can absorb, but shouldn't there be a certain variation of the amount she takes in at different times?
I really do not know enough about this and am mainly guessing, I am sorry if i suggested something stupid...

[Colin D Wilson]

Nothing stupid there,

I was refering to the spider being at "full throttle" as it were therefore being at it's highest level of intake.

Colin.

just as a matter of interest, already discussed in this forum, wikipedia entries can be edited by anyone so therefore i wouldn't refer to them as gospel, one of the members of the forum has already corrected a few entries.

[Sarah Katharina Franz]

"body functions needed for running intefering with the functions needed for breathing (high pressure in the prosoma interferes with the circulation of hemolymph from the book lungs within the opisthosoma)."
thats really interesting!
So after they run out of oxygen they use anaerobic resoiration to keep them going just a couple seconds more, but because it is very inefficient (well it always is... seems like a waste of glucose in comparision with aerobic respiration) this doesn't meet their needs either and just extends the time for which they manage a bit?
Sounds like a very inefficient system.. but when you think about it there are very few times in the life of a spider where it has to move fast for a long time... its usually just a quick short go back into the web/hide, letting oneself drop, or one fast move to actually grab the prey... so I suppose thats ok.
Another thing... I once saw a video of an Avicularia versicolor swimming. Apparently this is a way to get away from potential enemies, something they do more or less volunteeringly, and something they survive: they let themselve drop from their branches into the water below, and simply swim off.
[ame]http://de.youtube.com/watch?v=91eYqBn4RXM[/ame]
From what i can see, the book lungs are submerged under the water.
This would mean
a) The spider doesn't receive any oxygen while she is swimming(unless she absorbs it out of the water which i highly doubt) swimming should be somthing that is very strenious, and she could only take the energy from the inefficient anerobic respiration, plus her oxygen reserves. Doesn't sound very good.
b) The book lungs might get damaged.
I can't imagine what water does to them, but it doesn't sound good, and I don't know how she would get it out again...

maybe there is a thin layer of air under the book lungs saving them, kept up due to the hair on the tarantulas body...
I think I heard of something similar with the water spiders, that actually live under water...
could you explain it to me?
Thank you very much!!!

Edit: I am aware of the fact that anybody can enter anything into wikipedia, and have corrected articles there beforehand myself. i still think Wikipedia is a fabulous idea, and i usually find the information there is good for getting a general idea, seeing as its a rather basic and simple approach. Also there are many ways in which wikipedia tries preventing mistakes, eg. people having to list their sources, people being banned, discussion boards etc.
But I mentioned Wikipedia was were I had got the information because i thought it might not be 100 percent true. I just thought what they had written sounded sensible.

[Colin D Wilson]

i've seen first hand spiders running across water by adding a shallow water tray to the bottom of my Avicularia sp guyana enclosure.

i would assume that the hairs around the book lungs would trap air and therefore protect the intake of fluid for a short period of time, very simlar to the specifically evolved hairs around the water/diving spiders you mention. In this scenario an air chamber/bubble is trapped by the hairs as the spider enters the water and it draws oxygen from this in the time it remains submerged.
also the branchial opercula (the opening of the lungs) are able to be opened and closed... thus further protection.
plus as i have said they technically hold their breath so again, no intake of fluid.

[Sarah Katharina Franz]

Thanks again. The information you provided was brilliant. Looks like this is a wonderful forum. )

[Phil Rea]

I have seen videos of Avicularia spp. 'swimming' in the wild, when their habitat is flooded. I would think seeing as there's no active respiration within the booklungs, that water molecules are too large to pass though and into the spider's system, and if they 'drown' then it's from lack of oxygen, rather than fluid intake.

True spiders with spiracles would be a different matter. They process oxygen more efficiently, as they are more highly advanced (in the evolutionary sense) than mygalomorphae.

[EDIT] There you go - swimming avic [/EDIT]

[Sarah Katharina Franz]

Even if the water molecules don't pass through, won't they damage the system anyhow?
I don't really know how these lungs are structured, but if it consists of these thin fragile layers, won't they break or stick together when wet? And wouldn't the water cling to them, preventing air to get there?
Also I have heard that mould, fungi etc in terrarium are mainly dangerous because the book lungs become infected... isn't something like that likelier when they are wet?

[Phil Rea]

They're constructed like the pages of a book, hence the name. Water won't be able to permeate them, because if it did, then the hemolymph would also be able to permeate the other way.

Water won't damage them as far as I'm aware, but fungal infection will interfere with (or stop) the oxygen exchange entirely. It blocks up the lung in effect.

[Sarah Katharina Franz]

"They're constructed like the pages of a book, hence the name. Water won't be able to permeate them, because if it did, then the hemolymph would also be able to permeate the other way."
Sounds sensible. Hadn't thought of that.

[Phil Rea]

I've posted a link to the swimming avic video in one of my posts on the first page of this thread.

An excellent book that would be of interest to you by the sounds of it is Biology of Spiders - Rainier F. Foelix. I noticed from the introduction thread that you live in Germany. It was first written in German, but is also available in English

[Sarah Katharina Franz]

Thanks for the suggestion! I have found both the German and English version at Amazon, sound very interesting. looks like the german version is out of print, though. I think I will buy it, but preferably from my local book shop if thats possible.
I have also heard really interesting things about spiders moving via water pressure... but I don't even know enough about that to ask questions yet. They are sure to come though.