Is anyone working with a pressurized tank yet?
It's definately on my agenda. What do you know of them? My intended species to contain is the Gulper Eel.
http://www.mbayaq.org/efc/living_species/default.asp?hOri=0&hab=9&inhab=186
I haven't tried or really heard of any private collector that has. Mostly that seems to be in the realm of the large public aqarium. Not saying that it would be imposible just very difficult and probably not needed anyway. The fish will adjust to a lower water presure if bought to the surface slowly anyway. Otherwise their swim bladers prbly won't make the trip. I'm just afraid that they may be very difficult to find. Not depresurised properly and you are going to need an industrial sized chiller for your tank. I wish you the best of luck and would be very interested in following your progress in this enterprise. However I would also encourage you to deeply consider these issues and any others brought up by our more informed cohorts.
Warm regards
Chris:p
as an after thought besides being most likely not needed. They may also explode . We're talking several atmospheres of pressure here.
Alastair
02-06-2004, 1:46 PM
To add on to what maxilaria has said, construction of pressurized tanks can be tricky. Approximately every 30' of water depth is equal to one atmospheric pressure (14 psi). To think about it this way, the pressure at 300' of depth is ~140 psi, which is pretty close to the long term limit of schedule 40 PVC pipe.
On the other hand, fish are not widely succeptible to pressure related issues since their bodies are primarily filled with water, which does not compress or decompress under pressure. That differs from people who have large voids of gas (i.e. lungs, etc) which collapse under pressure. So the main issue, as maxilaria noted, is the swim bladder -- but as long as the adjustment takes place slowly most fish can adjust fairly well. The other issue is that gasses dissolve more readily into a liquid under pressure, so there is likely more gas in solution at depth than would be supported by the water at the surface. That means gas has a tendency to exit solution following a drop in pressure, forming embolisms and such, a condition commonly known as "the bends" in human divers. Again, slow pressure changes would be key to this.
On a side note, the Wakiki aquarium had success breeding the chambered nautilus -- a creature which undergoes huge changes in depth / pressure on a nightly basis. They apparently found that the regular fluctuations in temperature associated with this diurnal migration were more significant than the changes in pressure.
I hope that's of some use.