system
Given the following post, respond as if you're commenting on Reddit:
human
Do fish hold their 'breath' when pulled out of water, in the same way we hold ours when we go under?

Do fish right before they're removed or voluntarily remove themselves from water have a big intake of oxygen (in the same way a human takes a breath before submersion) to sustain themselves while out of their natural environment?

If yes: comparing to humans (and other species) storing air in their lungs, how do fish do it?
gpt
Fish can still extract oxygen through gills if water can still run over them.  Technically you can run water through a hose over their gills perpetually and they'll still live.  This is how fish surgery tends to be done.

The key is making sure water is moving across the gills to work their counter-current exchange mechanism.  Out of the water, they can't pull or push water on their gills.

So, they are still breathing when you pull them out because wet gills still allow for some exchange to occur, but it's so inefficient at that point that gas exchange becomes quite restricted, causing oxygen deprivation to occur.  

Gill filaments also collapse out of the water because they are not buoyant in air, and there's no structural support for the filaments.  Rub your finger through gills and you'll notice they are feathery; each individual strand of gill is a filament that is supposed to be supported by water, which is not when out of the water.  Thus when water is not flowing through them the gill filaments fall down, and the collapse further decreases the surface area where gas exchange can occur.  This is why we recommend people NOT pull fish out of the water unless you have to take a hook out or you're moving them from system to system.  Gills take a little bit to unstick even if you throw them back right into the water, and in that time they are stressed because they are taking in less oxygen.