10 ms·
Deepest fish ever caught on camera off Japan
- Waterluvian 4y ago> At 8km down, they are experiencing more than 80 megapascals, or 800 times the pressure at the ocean surface. Is this somewhat a coincidence or is this the beauty of the metric system?
- dakial1 4y agoThis is rounding. 8km would actually be 80304.7 kPa. So not as beautiful as you imagine.
- Waterluvian 4y agoI’m guessing the salinity of the water might affect the pressure?
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- lostlogin 4y agoPossibly offset by the volume of fish.
- elorant 4y agoEvery ten meters pressure raises by one atmosphere. So I'd say it's just a coincidence.
- Ekaros 4y agoI think it is just that gravity happens to be 9,81 m/s^2. On other hand 1kg being equal to 1 litre of water is by design in metric system. Other happens stance is that pressure on surface is about 101 325 pascals. So things work out that way...
- fredley 4y agoI'm reasonably sure they're not identically accurate any more, but good enough for the kitchen. The kg was initially defined by the mass of the water, but as the kg has been redefined it's drifted a tiny bit.
- red_trumpet 4y agoI guess in this context the more significant factor is that seawater has a slightly higher density than pure water.
- morjom 4y agoApparently the "new" kg (based on meter and second) is within 30 ppm (parts-per-notation, TIL) of mass of 1 litre of water.
- fredley 4y agoLike I said, good enough for cooking!
- amelius 4y agoThose factors of 10 don't really look so nice if you use e.g. the binary number system.
- ralph84 4y agoIndeed. And the SI defining constants are downright ugly.
- lostlogin 4y agoYes, give me chains, barley corns and furlongs so that we have nice folksy constants.
- ralph84 4y agoThe 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 SI is no less outdated than those units, but we hold onto it for backwards compatibility.
- Aardwolf 4y agoPerhaps 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
- dmix 4y ago> 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. [1] https://www.americanscientist.org/article/creatures-of-the-deep-karst https://www.americanscientist.org/article/creatures-of-the-d...
- bobthepanda 4y agoI 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.
- Retric 4y agoCreatures 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.
- noduerme 4y agoI'm sort of curious how they don't simply explode when you bring them to the surface.
- oesexe 4y agoI 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.
- nntwozz 4y agoIf 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).
- dmix 4y agoNeat, the wiki for that fish: https://en.wikipedia.org/wiki/Pseudoliparis_swirei https://en.wikipedia.org/wiki/Pseudoliparis_swirei > 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.
- undersolved5 4y ago[flagged]
- transcriptase 4y agoAn 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.
- another2another 4y agoProbably also avoid predators, since they seem to be pretty much by themselves down there.
- crazygringo 4y ago
- mytailorisrich 4y agoI've found a 2014 article by the BBC that explains why fish are not expected to survive beyond about 8,000-8,500m: https://www.bbc.com/news/science-environment-26423203 https://www.bbc.com/news/science-environment-26423203
- bjelkeman-again 4y agoFrom the article > 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.
- culi 4y agotl;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.
- ericrallen 4y agoI just recently read the Brilliant Abyss[0] and it was a really interesting look at the deep ocean and the complexity of life down there. If this kind of thing interests you at all, I highly recommend it. I didn’t know much going in, but found it fascinating. [0]: https://helenscales.com/portfolio/the-sea-beneath-us/ https://helenscales.com/portfolio/the-sea-beneath-us/
- joshuahedlund 4y agoI just read this as well, excellent and fascinating stuff! I thought I already knew a lot about “deep ocean life” but most of it was brand new to me!
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- bmitc 4y agoWhat does water "feel" like at that depth? There is a lot of weight felt I guess from the pressure, but is it thicker to swim through in some sense?
- RicoElectrico 4y agoWater is incompressible, so I think it should behave similarly. Even viscosity remains within a few precent [1] (Mariana Trench is around 100 MPa) [1] https://www.engineeringtoolbox.com/absolute-dynamic-viscosity-water-d_575.html https://www.engineeringtoolbox.com/absolute-dynamic-viscosit...
- bmitc 4y agoInteresting. 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.
- daveslash 4y agoMost 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.
- sixQuarks 4y agoI’m wondering the same thing. You can see their fins flopping around as if it’s regular depths
- terlisimo 4y agoDSSV 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". https://theculture.fandom.com/wiki/List_of_spacecraft https://theculture.fandom.com/wiki/List_of_spacecraft
- rowanG077 4y ago[flagged]
- Kaibeezy 4y agoAh, thought you were talking about Tangents, the Greg Bear short story collection.
- felixyz 4y agoThe Incredibly Tangential Information must be another Culture ship?
- jallen_dot_dev 4y agoGCU Low Quality Tangent
- sangnoir 4y agoGCV I'm Getting Fed Up sounds like a ship that was involved in more than a few skirmishes during the Idiran war.
- prawn 4y agoI 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.)
- 4y ago
- dinvlad 4y agoI 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.
- gnatman 4y agoAnd in fact they’ll thrive as more and more detritus rains from above!
- xwdv 4y agoIt infuriates me when they bring these fish up to the surface, killing them painfully as the decompress into disgusting blobs.
- neitsab 4y agoSurprised no one shared this one yet. In case you've never seen it: https://neal.fun/deep-sea/ https://neal.fun/deep-sea/
- 2wrist 4y agoThat’s ace! You don’t expect to see some animals dive that deep!
- pvaldes 4y agoI can imagine similar tricks and shapes on life forms from Jupiter's Europa
- penguin_booze 4y agoDear fish, congrats on meeting the human race. Now please stay away from us at all costs--no other species had had a good time having met us. Your affectionately, a regular, concerned, human.
- blackoil 4y agoMust be something due to lack of light and pressure, but all deep water fish seem to be so ugly!