DSSV Pressure Drop sounded like a Culture ship name to me so I looked that up. It's not, but the name of the DDSV, "Limiting Factor", is. Apparently they also named their utility boats after Culture ships.
To those who don't know: "The Culture" is a... society(?) of godlike AI ships/minds from the series of SF books by Ian M. Banks.
SpaceX named their landing barges after Culture ships too, the "Of Course I Still Love You", "Just Read The Instructions" and "A Shortfall of Gravitas".
And that wiki directly mentions DSSV Pressure Drop because the expedition support ship of the Five Deeps Expedition has utility boats named after Culture ships: Little Rascal, Liveware Problem, and Learned Response.
This is the rare kind of comment that I can't relate to. I disagree with lots of things people say, sometimes diametrically - I might even consider some of them immoral, or feel angry about it. But I still can comprehend the frame of mind that can produce their point of view. But once in a while I can't even do that, even if the comment itself is not particularly wild.
I don't agree that this is low quality, but if you haven't already, maybe upvote the other top level comments? (At time of my comment, this is the top thread on the page.)
> It rests on the particular molecular mechanism they use in their tissues to withstand crushing pressures.
To go deeper would require fish to evolve some other mechanism, the team tells the journal PNAS.
The all-important molecule is a so-called osmolyte called trimethylamine N-oxide (TMAO). It is what gives fish their “fishy smell”.
TMAO acts to stabilize the proteins fish use to build and maintain their cells.
Without its presence, the proteins would be distorted by the high pressures found at depth and stop functioning.
tl;dr: Fish rely on an osmolyte called trimethylamine N-oxide (TMAO) to stabilize the proteins used to build and maintain their cells. The concentration of TMAO seems to be extremely reliably correlated with depth and we know that at a certain concentration TMAO makes proteins too stable to work correctly.
Other organisms like crustaceans are able to occupy deeper parts but they use 5 different osmolytes for this purpose whereas fish have only ever been observed using this one.
The supposed beauty of SI comes from (most) people having 10 fingers, so it has its folksy component. But SI doesn’t work well with computers and its defining constants are ridiculously ugly and inaccessible. SI is no less outdated than those units, but we hold onto it for backwards compatibility.
Perhaps humanity should have chosen base 12 (or, of course, base 16) at end of 18th century.
With base 12 SI units at least some argument for imperial units would be gone, that is that some of their ratios are easy fractions. Not that this makes sense since the ratios of different imperial units are different random numerical values, and nothing prevents using fraction notation with metric units
> Likewise, their approach to food - they are suction feeders and consume tiny crustaceans, of which there are many in trenches.
I remember James Cameron’s dive and the main life pictured was crustaceans. I’ve also read they are a significant amount of life in underground aquifers [1] was crustaceans, which also had blind reptiles which also fed on crustaceans and had transparent skin similar to those snailfish. I’m curious what makes them so unique to flourish in these sorts of places.
I would imagine it is the extreme pressure. At that kind of depth you either need a really strong body and small surface area (tiny crustacean) or a gelatinous body where that doesn’t matter (snailfish). Those are probably disadvantageous at lower pressure environments. (I’m curious how molting would work at high pressures though, since the crustacean would lose its shell.)
as far as blindness, there’s not really visible sunlight reaching there, so sight probably doesn’t do a lot, and eyeballs are squishy.
Creatures living in the deep simply equalize their internal and external pressures and don’t feel the pressure as some kind of weight they need to withstand.
This is why when you bring them to the surface quickly they die from the sudden decrease in pressure. As to eyes bioluminescence is common in the deep and nothing would bother if nobody had eyes.
I have caught quite a few red fish in Greenland. They ‘only’ live a hundred meters down, but sure they kinda explode when surface. Eyes pop out, and their swim bladder pops out of their mouth.
If they get unhooked on the way up, they will also surface themselves.
The problem is gasses both dissolved in tissues which causes cellular scale damage (Aka the bends) and internal pockets of air such as in swim bladders which can rupture.
It says that fish use the TMAO protein to protect themselves from pressure. But other organisms use a combination of multiple proteins and that apparently lets them survive higher pressures.
So it seems the fish would basically need to re-evolve how to handle pressure, but in a different way, to be able to go deeper.
Temperature and pressure are very related. Fish that live at 8400 meters are dealing with pressures/temperatures/energies that need additional attention. The biological processes of fish start failing at the pressures of 8500 meters or whatever, doesn't matter if the fish has the same internal and external pressure, the pressure has impeded the effect of some protein.
Interesting. Thanks! Upon doing some searching it seems that the water at the bottom of the Mariana Trench is just 5% more dense. I didn't realize that water was that resistant to being compressed.
Most fluids are pretty resistant to compression. That's what makes them so good for hydraulics, for example brake lines, etc.... by putting fluid in a tube, you can apply pressure at one end and bend it around all kinds of crazy corners and curves and get the same pressure applied on the other end.
I wonder if this fish will be crucial to the survival of life on Earth, if the climate change gets out of control. I would imagine the conditions at the deepest levels of the ocean won't change much, allowing their natural habitat to continue.
If you ever wondered how they survive the pressure, from wikipedia:
TMAO (Trimethylamine N-oxide) is found in the tissues of marine crustaceans and marine fish, where it prevents water pressure from distorting proteins and thus killing the animal. The concentration of TMAO increases with the depth at which the animal lives; TMAO is found in high concentrations in the deepest-living described fish species, Pseudoliparis swirei, which was found in the Mariana Trench, at a recorded depth of 8,076 m (26,496 ft).
> Compared to shallow-water snailfish, Pseudoliparis swirei has several unusual adaptions for its dark and high pressure habitat, including transparent skin that lacks pigment, certain organs and eggs that are enlarged, the muscles are thinner, the ossification of its bones (notably the skull) is incomplete, it appears to have little or no ability to see, there are mechanisms that allow proteins in its body to still function, and differences in the cell membranes for maintaining their flexibility.
An interesting case of evolution. In theory the first populations to become fixed for an allele or allelic combination that results in even a small increase in TMAO would be able to access previously untouched feeding grounds and flourish for some time.
Yeah, the cited depth limit of ~8.5km appears to be based on “fish use an osmolyte called TMAO to protect their proteins from pressure, and below 8.5km the concentration of TMAO required is so high that it inhibits cell function”. Apparently crustaceans get deeper by using five different osmolytes at once instead of relying on TMAO. (Info from helpful comment by mytailorisrich in this thread https://news.ycombinator.com/item?id=35403838)
To those who don't know: "The Culture" is a... society(?) of godlike AI ships/minds from the series of SF books by Ian M. Banks.
SpaceX named their landing barges after Culture ships too, the "Of Course I Still Love You", "Just Read The Instructions" and "A Shortfall of Gravitas".
https://theculture.fandom.com/wiki/List_of_spacecraft