question about the sea. If you found a fish at the deepest part of the sea and brought it up to the surface really quickly would it explode, as a goldfish would implode if you took it to the bottom of the sea.
Based on my meagre knowledge of diving physiology I have allways assumed that it would. The lungs sure do if you get up to fast from a deep dive. Apart from the bends that's one of the most common causes of death in scuba diving. So it sure should be the same for deep water fishes I assume.
Firstly a goldfish won't implode when you take it too deep, it'll just die. It's swim bladder will expel gas until it's completely empty, compressed down to nothing, and it would be fine. For implosion you need a rigid gas pocket, like your chest cavity, sinuses or eardrums. What'll kill it will be a combination of sensory overload, it's unprotected neurons will fire at a ridiculous, uncontrolled rate causing it's body to spasm, possibly with sufficient strength to break it's own back, and the complete breakdown of it's metabolism as it's unprotected proteins unravel under the pressure.
Bringing something up is a whole different story. Theoretically it should be physically fine but poorly adapted to it's new environment, it's neurons will fire very slowly possibly slow enough to kill it. In reality what happens is the fish is usually brought up too quickly. Most deep sea fish have a blind swim bladder, there's no holes in it. Gas is exchanged in and out via the blood. This is an incredibly accurate way of maintaining correct buoyancy but it's really slow, you can't just blow off gas, like a surfacing diver can from their lungs. Which means the swim bladder expands massively as the pressure on it is released. Theoretically this could lead to an explosion but what happens in my experience is based on the facts that the swim bladder is enormously elastic and the body of a fish
isn't a blind sack. The bladder expands and becomes too large for the body cavity and so it makes room by pushing all the fish's internal organs out through it's mouth, finally pushing much of it's own way out. It isn't pleasant to look at
