What would happen to a high-pressure creature in a low-pressure atmosphere (50atm)?

Question

Answer this question:

"What would happen to a high-pressure creature in a low-pressure atmosphere?

The hypothetical creature has evolved on a planet with an atmosphere that's much more pressurised than that of Earth. It's humanoid in appearance, in that it has two arms and two legs as well as a head bearing a mouth and eyes. Its native planet has an atm pressure of, say, approximately three times that of Earth. It usually wears a pressure suit to deal with an atm pressure more akin to what we're used to here on Earth — so if this suit were to be removed or damaged, what would happen to the alien? I'm looking for specific symptoms, here. Describe it as if you were describing what would happen to a human body in the vacuum of space.

Here's some additional anatomical & biological details to help you: It's thin and gangly, with a slim figure and very thin extremities. It stands, on average, slightly smaller than your garden-variety human (5.5 feet, usually). Its bones are quite small and thin, almost like fish bones, and most of them are connected to each other rather loosely. They kind of just 'float around' in the body, supported by the high pressure atmosphere, and are filled with a jelly-like fluid. It has a single lung-like organ — gas is sucked into this organ where it comes into contact with various, inward-pointing 'stems' which have a rich blood supply. It inhales this gas through both its mouth and a secondary hole in its ears, but it has no nose. Its blood is yellow because it contains a lot of sodium. It has four eyes, behind which lie sinuses that are filled with fluid (again, to do with dealing with high pressures). It has a rather thick neck, containing lots and lots of blood vessels and airways, which are both generously coated in rigid chitin to prevent them from collapsing due to the high pressure. Its heart is very thin, but very long, running the length of its torso down to its pelvic region (almost like an insect heart). Needless to say, it has a very high blood pressure. Paradoxically, its native planet has very low gravity, so the pressure suit comes with in-built leg supports to help it deal with a higher gravitational stress than what it's used to.

Thank you! The more detailed and gruesome your answers, the better."

-but instead, raise the atmospheric pressure of the creature's home planet to fifty times that of Earth. Have fun, and make sure to read the question very carefully!

Answer 1

While the existing answers are correct in saying "nothing dramatic" you could make it dramatic.

If you modified the aliens physiology and gave them air bladders that they use for some purpose - perhaps they are semi-aquatic and use small bladders all over their skin to alter their buoyancy.

Those bladders would be filled by air at 50* our pressure. Any sudden shift in external pressure that happened faster than they could compensate for would cause those bladders to rupture and burst.

This would most likely not be immediately deadly but it would be very painful, and very messy. Skin would rupture and even explode, popping and banging noises might happen. Bodily fluids would fly around, circulatory vessels would rupture and spurt out alien blood, etc.

Answer 2

You're going to start with a very serious case of the bends. I suspect you're looking for something resembling explosive decompression, but using the example of deep sea fish brought to the surface, while they die, they remain physically intact.

Answer 3

What's the pressure at Earth's abyssal plain? What ocean zone does 50 atmospheres correspond to? I think you'll find that this is in the same league as the earlier question. 3x, 50x, same difference as far as chemestry is concerned.

But I note that this is the start of the abyssal zone. Air is still air, but becomes dense and viscous and the creature could not have the same kind of lungs or easily push gas through a pipe.