# Anomaly of a spider

1. May 17, 2008

### mapsurfer

This is a wierd one... I had been observing a spider in the skimmer of my swimming pool.
I had the top of my skimmer on with no hose attached, which created an enormous suction
and I had left it like this for a few days because it seemed that the skimmer vortex was much stronger... This increased suction pulled everything to bottom of the basket.... I had looked in there a few days ago an noticed this huge brown spider in the bottom of the basket. I thought this spider was dead as there was no possible way a living air breathing creature could survive.. I pulled out the basket and low and behold, this damn spider jumped to life.

I had no idea spiders could survive underwater for extended periods of time. He must have been able to trap his own air because I *know* he wasn't breathing water.. Was he?

Nature is freaky!

Regards,

-map

2. May 17, 2008

### Danger

Insects and arachnids don't 'breath' in the way that we normally think of. Rather, they have holes along their bodies that allow air to enter and be absorbed by the circulator system. (They also don't have 'blood'.) There appears to be some ability to diffuse oxygen out of water. I've held a regular housefly under water for a couple of hours, and it didn't seem to care. (Well, it was probably somewhat pissed-off, but it was alive.)

3. May 17, 2008

### mgb_phys

Spiders can also form air bubbles around themseleves and survive underwater for a long time.
An insect not doing anything doesn't use very much oxygen and when you are that size surface tension is a big deal so water and bubbles behave very differently.

4. May 17, 2008

### mapsurfer

Yeah it was just really bizarre to me because this spider had been underwater (not just flitting about the surface, but totally submerged with a heavy suction vortex for several days)... stuck me as a freak of nature, but I guess spiders have evolved or adapted to accomplish this task. Makes you wonder what other creatures could adapt to survive in such a manner. A "FLY??" That gives me an idea for an experiment...cuz I dont like spiders.

Nature never ceases to amaze me.

Regards,

-map

5. May 17, 2008

### Danger

Good point about the surface tension. Things at that scale are indeed vastly different. Water bugs use that to walk around on the top of a pond, you can drop a bug from 2 metres onto the ground it it won't even notice, and fleas absorb something on the order of 1,000 g's when jumping. Unbloodybelievable!

6. May 17, 2008

### Moonbear

Staff Emeritus
How do you know the spider was there several days and hadn't been sucked in only moments before you arrived to clean the skimmer?

7. May 17, 2008

### Danger

It's hard to tell what's going on with bugs. Spitfire (a cat that I rescued from being entangled in my hedge when he was a couple of days old) was pretty much feral other than the fact that we wouldn't let him out of the house. His one cat-like occupation was playing with pinecones. One day my mother heard this horrendous howling coming from her bedroom and went to investigate. There was Spitsy batting away at this pinecone and yowling like he was being gang-raped by priests. Upon further investigation, it turned out that the 'pinecone' was a honkin' huge beetle that had its mandibles firmly clamped onto my cat's nose. My mother knocked it loose and stomped on it (and she was pretty fat in those days). I then put it in a small baby-food jar, sprayed in so much Raid that there was 1/8th inch of liquid in the bottom, screwed on the lid (with no air holes in it), and placed it on the window ledge of our back porch. That damned thing took four days to die. :surprised

8. May 17, 2008

### mapsurfer

No I had been visually observing the spider in the bottom of the skimmer basket for a few days... only noticed him because he was really big but I did not empty the basket for another
2-3 days. Although this wasn't scientific at all, I am in no way exaggerating the the amount of time. I usually look in the skimmers every days and empty them when they get really nasty. Also, the skimmer lid (the thing that reduce the big hole to a small hole) make this vortex which for some reason makes the skimmer work better (pulls the debris from the pool better). Most animals area dead meat if they get in the skimmer, but the spider was a real diehard son of gun. Next time I can capture a spider, I will see if my result are repeatable. LOL

See ya,

-map

9. May 17, 2008

### Moonbear

Staff Emeritus
How far down does the vortex go? Maybe it has positioned itself to get the air circulating down from the vortex?

Or maybe you need more chlorine in your pool. :uhh:

10. May 17, 2008

### mapsurfer

The skimmer is about 10 inches deep and the basket extends into it about 8". The spider was
in the very bottom of the basket. just sitting there on the bottom. The vortex is just heavy suction, like a whirlpool at the top. Reminds me of a mini black hole. Im sure there was quite a storm inside the skimmer chamber and I am 100% certain this spider was stuck
on the bottom of the basket. The vortex was pretty strong... no way for him just to swim
up to the surface.

Heh, yeah I keep my pool chlorine perfect, but I dont think chlorine at 2.0-3.5ppm is very lethal (even for a spider).

Im gonna try again (if I can find another pool spider) and see what happens.

I'll post again as soon as I can start my experiment.

-map

11. May 17, 2008

### Moonbear

Staff Emeritus
I didn't mean he was swimming to the surface. That vortex has air in the center. If it was getting down far enough to the bottom, the spider might have been sitting right in the middle of it getting just enough air at all times while sitting on the bottom.

12. Jun 4, 2008

### GhostOps21

Interesting

Under my computer desk, I commonly find spiders or other bugs, but tonight I found two spiders
either fighting or mating, I think fighting, but anyways, I have a jar that I keep down here for insects that I find. I scooped them both in it and watched them fight/escape. After awhile they became stiller, and I added water (>:D), first like a centimeter, and one all of a sudden tried to climb up the wall and collapsed suddenly and died, and I don't think he drowned. Then i added like an inch or so, and the last spider has been fighting to survive I think, but I noticed he floated, so I swirled it around, and observed. He has a bubble of air around his abdomen. He's been living for about 10+ minutes. I check with am extended paperclip, and he is still living. I'll keep updating on his status, but I think the air bubble think is correct. Also the first dead one does NOT move what-so-ever. I even get him out of the water. Maybe the other one poisened him? I don't know, it's just the Colorado mountains =P. lol

13. Jun 4, 2008

### Staff: Mentor

First off, the diving bell spider, Argyroneta aquatica, sometimes called a water spider, spends all of it time underwater. Literally. So just because you have a spider that has been underwater does not mean it will die, a priori.

Arachnids are poikilotheric, cold-blooded, so they require like 1/10th the $$O_2$$ per minute that mammals like us require. At complete rest, a spider's respiration is really very low, meaning they need miniscule amounts of oxygen.

Next, spiders have spiracles, those holes for breathing that danger mentioned. Due to the surface tension of water, and because the holes are such a small diameter they do not fill with water when a spider is underwater. This in general is why little bugs with spiracles don't all drown during a rain storm.

So, with a spider at rest underwater, the remaining air in the spiracle cavities provides enough oxygen for many hours.