My question is how long can they stay alive under water? Pulled a giant hairy one out of the pool early this morning, sat it on our table and it started to walk away hours later. Have no idea when it fell into the pool but I'm thinking it was during the early morn.

DesertWRX:

If I recall, arachnids along with some insect species possess what are called "Book Lungs" which are not analogous to mammalian lungs. These respiratory organs in the abdomen (mesosoma) receive air via several spiracles (openings) located on each 'plate' of the mesasoma to facilitate gas exchange. If I remember correctly, they can be closed-off temporarily to keep the animal from drowning. I'm not sure how long a scorpion can remain under water but it is quite a long time due to their low oxygen requirements and personal experiences.

I hope this helps in some way. If I am incorrect here or on any of my posts, hopefully someone out there can set me straight and thus help us 'all' learn. I do like getting involved in interesting questions when I can but more importantly, I love to learn from this site, the various forums and knowledgeable individuals. -- Danny M.