It is often mentioned, this crushing pressure of the deep.
We can barely put together a high-tek vessel strong enough for that environment.
Yet, when we manage to get down there and make observations, what we often see is fleshy creatures, not a whole lot different than ourselves.
From casual reading, one might expect that the only beasties that could manage such depths would surely require spherical-shaped units of 2' thick stainless steel.
Fact of the mater is, the usual, primitive protoplasm of the sort that we are comprised of, is actually up to the task. Inhabiting these exotic realms has not required extraordinary technology, nor even extraordinary life forms.
Even mammals, with red blood and mammary glands, have managed depths beyond most of our best technology. This is why I mentioned the plastic bag, versus the amazing architecture. The odd fish and invertebrates that we've seen in the deep are not particularly of different design and structure than anything we observe in shallow water.
Its simply a different niche; a poor one perhaps, with more limited exploitation opportunities...but not one that requires a whole new physical design, with super-awesome crush proof body types.
There's mushy bodied worms down there, with no amazing titanium exo-skeletons.
Its just regular old biology, plus some cool bio-luminescence tricks and such.
I mention the rather obvious here to distract from the misunderstanding that is often promulgated concerning these extreme conditions and our difficulty at accessing them.
A shark that manages life 2 miles down in the ocean is not enduring horrendous pressure. Its not down there being crushed by awesome forces. It doesn't require an extraordinary bone structure. The forces don't make its eyes bulge out nor flatten its head into a unique configuration.
I state the obvious, perhaps, for this forum, yet I sense that the general populace can't get their minds around this. One might expect to only encounter life forms at depth that resemble our finest attempts at building crush-proof containment. But that's not what is going on.
IMHO, we are going about this exploration in a radically wrong-headed way.
And it may be flavoring the way we view the limits of various ecological niches...here, and elsewhere.