It is not good to be a weightless fish

Maybe somebody who speaks German can explain why this poor goldfish is being tortured. It's certainly interesting to watch the water in its tank float and blob around — while the fish struggles to follow. But I'm really unclear on the point of this particular experiment.

Via Miriam Goldstein



  1. The experiment would be a lot less torture-seeming if the tank was full of water, not half-full.  I would like to see how a fish deals with a lack of gravity, but it’s hard to tell with the air bubble confusing the fish.

    1. Agreed.  I was imagining how I would react if I were floating in a sealed room and a cube of water kept randomly attacking me.

    2. The experiment would be a lot less torture-seeming if the tank was full of water, not half-full.

      Except for the whole “getting oxygen into the water” thing.

      1. It takes a good while to use up all the oxygen dissolved in water. They could certainly have sealed it up for an hour and then opened it again without killing the fish.

          1.  They could aerate it in between dives. Or use more water. Or pressurize it with an O2 enriched gas mix. The video is only 1:19 long.

          2. No need: the experimental flight phase does not last very long. Given the size of the fish, it would not have been a problem. But then, the point of the experiment was possibly also orientation in relation to a water surface.

      2. When I was in high school, one biology demonstration that had been used for a couple of years by that point was a mason jar filled with water, rocks, a couple of fish, and a few plants, then sealed.  Even though the jars had been sealed for over a year before I joined that class, the fish and plants were still alive.  I’m sure a similar thing could be arranged, for a long-term microgravity experiment.

  2. Well, it’s N24 which is sort of a weird 24 hour news service. It seemed to me like they were just trying to gather information about how a fish would respond to zero gravity, but without the intro it’s a bit hard to tell exactly what’s going on. Also seems like they could have just filled the tank all the way, but the fish seemed to do a pretty good job of staying in the water anyway.

    1. I think it’s actually more interesting because it wasn’t entirely full, and yet, as you pointed out, the fish manages to stay in the water pretty well anyway.  Which means even without the convenient gravity-cues that mean water is always “down”, the fish can still orient itself towards water.  (Though once he’s IN the water, he seems pretty confused as to what “up” is.  I imagine it might not be important though)

  3. The point of this experiment is to get the experimenter into weightlessness. The ‘goldfish’ is, in fact, a red herring…

  4. It’s not particularly mentioned in the Video… all that is said is that “A Goldfish struggles with the lack of gravity” and that “we still know to less about the loss of gravity”…
    But as far as I can tell, the report is not about the golfish, but about Zero-G experiments on board of aircrafts…

  5. Doesn’t explain anything. Just that the fish has trouble w/out gravity (first sequence), that a bottle flies through the cockpit (2nd seq.) and that we still don’t know enough about gravity. (Duh)

    1. That experiement just basically just used as background footage for this so-called documentary. The narrator doesn’t understand what it’s about, he’s just talking to fill the time.

      N24 was originally a 24 hour news station, then they started airing old documentaries, then they started to produce some.
      If you try to send information 24 hours a day, the density of useful stuff gets somewhat reduced :(

      My take on the experiment: It shows how the fish is in fact able to evade the air bubble despite having no gravity. It also shows that the fish will not preserve its orientation (as opposed to other species who will try to keep their orientation relative to the environment constant, like humans).
      I trust that whoever designed that experiment knew what they were doing, because there is usually some competition in order to get a slot on these flights. After having seen two documentaries of much about the place I used to work for, I do no longer, however, trust journalists to understand and properly communicate what the research is actually about. If all goes well it’s superficially accurate. This one is superficial to begin with.

  6. It may be a part of the series of experiment from the German Aerospace Center (DLR) 2009 a news report stating that the fish tank serves as a model for the human inner ear.
    A paper published by the group: Gravitational Zoology: How Animals Use and Cope with Gravity

    1. Yes the paper seems to support that. Part is indeed about finding out which orientation the fish will keep in microgravity (answer: It uses the strongest light source as “up” — if gravity and light source do not agree it uses some kind of average between both directions)

  7. That’s a bit cruel. They could have put the fish in a plastic bag and sucked out all the air to keep it from air-drowning and panicking.

    As I see it this experiment is testing to see what fish do when they encounter air bubbles. All the data about how a fish acts in microgravity is mixed with how it reacts to unexpected air.

    1. They could have put the fish in a plastic bag and sucked out all the air to keep it from air-drowning and panicking.

      Because fish don’t need oxygen?

    2. From the book Colonies in Space “In a weightless space farm, it may be possible to raise fish without water. On Earth, when a fish is taken from water, gravity makes its gills collapse so that it cannot get oxygen. In weightless space these same fish might easily “swim” through an atmosphere of 100 percent humidity, keeping comfortably moist: hydroponic fish, if you will.”

    3. Might be the case that plastic bags could be a security risk if ripped open. To some equipment on board, that is. And to the fish, naturally.

  8. There’s science, and then there’s “Hey, this might be cool.  Let’s try it and  see what happens.”

    The line between them is often murky.

  9. it would have been nice to have a little food coloring in the water, to help tell the difference between air and water

  10. There have been proposals to raise fish in zero gravity in highly humid air. Fish gills can function, so long as they remain covered with water and don’t dry out, and so long as they don’t collapse in gravity. On earth, buoyancy supports gills, but in zero G, gills wouldn’t need to be submerged. We could have space colonies where people swim amongst the fishes and pluck them out of the air and put them in a basket. 

      1. And the fish occasionally getting away. On my second run through, I noticed that at one point the fish did get taken by surprise by the air bubble while moving too slowly for momentum to carry it back to the water around the edges. It did a WAY better job of orienting itself by thrashing and then “swimming” through air than I’ve seen even the most veteran astronaut manage. For a situation COMPLETELY outside of the evolutionary niche the species evolved in, that fish was doing remarkably well.

  11. Ein Goldfisch hat seine liebe Not mit dem Schwebezustand. “A goldfish grudgingly accepts (literally “has its beloved suffering from”) its state of weightlessness.”

    Selbst dem Cockpit eine kurze Irritation, als eine Flasche plötzlich zwischen den Piloten fliegt. “Even in the cockpit there is a brief moment of irritation, as a bottle suddenly floats in between the pilots.”

    Noch immer weiß man zu wenig über den Verlust der Schwerkraft. “Too little is still known about the loss of gravity”

    An Bord sind die Experimente angelaufen. Die Zeit is kostbar. “On board, the experiments have started. Time is precious.”

  12. To a foreigner, who has lived in Germany for three decades, it is impossible to ignore the subtle tone of disinterested sadism emanating from this combination of “experiment”, narration and narrator’s voice, which I find very German (in a more negative tuning of the word). My first stupid reaction was, “they couldn t find a Jew so they took a goldfish”. It is anti-German resentment, but there are also complex and real experiences fueling it. 

    1.  As I observed above: The narrator _is_ bored, and he has to fill many minutes of documentary with meaningless words.
      This is what that sounds like.

      Several close friends of mine have had bad experiences in Germany as foreigners. The amount of resentment you are displaying is pretty much what those people (and me…) hate in Germans. “Ahh, you’re from Transsylvania! Haha, Vampires, haha!”
      Also, the premise of what you’re saying there is that the sole purpose of this experiment was to somehow torture the fish? WTF?
      You offend me on both accounts: Your prejudices against science and people based on their nationality. If I’d known you in Germany and you started with such nonsense, I wouldn’t have wanted to have anything to do with you either.

      1. “If I’d known you in Germany and you started with such nonsense, I wouldn’t have wanted to have anything to do with you either.”

        How then did you become and have stayed friends with your “close friends” that show the same resentment? Also, it is resentment against a specific behavior, we happen to call it German. It has nothing to do with the totality of people with a specific passport. I do have resentment against nationality as such, but that includes all nation states and is a different discussion.
        And yes, disinterested sadism would be my term for practices that are detached from the notion of suffering and human interaction.

        1. Also, it is resentment against a specific behavior, we happen to call it German.

          Oh my. I’m not sure what to make of this line. “As we happen to call it in German”, or are you calling your resentments a German thing? And what, specifically? And then, what “totality” are you referring to in the next line? Is that German people, at large?

          First, you show your prejudices when pushing the antisemitic button, and fail to express anything specific, and then you can’t even express yourself properly? And not even get the facts straight? See, Zak McKracken said close friends of his had bad experiences in Germany as foreigners. Not that his friends showed any resentments. There were prejudices and stereotypes used against them.
          But then, pray, what brings you from a zero-G Carassius auratus to your hateful comments in the first place?

    2. It is anti-German resentment, but there are also complex and real experiences fueling it.

      Care to share? Otherwise, you just pull another Goodwin. Not even a good one.

  13. It’s also interesting regarding the plasticity of the brain in other creatures, when subjected to zero gravity. Will they completely fail or actually reason their locomotion to get back to safety. Cats for instance would pick a side, usually the bottom, and reorient themselves towards that in low gravity, giving us a look into how such animals react. The goldfish was always able to return to the water so it must have reasoned its movements out to get there, showing a remarkable adaptability for such a neurologically simple creature.

  14. I am totally and thoroughly disgusted by people who experiment on animals in this fashion and no. I don’t want to revisit the arguments for animal experimentation. Screw them.

    1. And there are people who are totally disgusted by those who consume the flesh of animals. And no, they don’t want to revisit the arguments for animal consumption. Screw meat eatters, right?

      People who have the time, skill, and resources to go into space don’t experiment like this to get a kick out of cruelty. They do it to try and learn things about the universe. A nobler goal than eatting merely to survive, no?

      Everything suffers. Everything dies. Most of the time, such suffering serves absolutely no purpose. So if you want to be self-righteously furious at something, direct your rage at fate, or chance, or whatever whims of the universe dictate that living things should die needlessly all the time, by no fault of their own or of others. At least then your anger would have no senseless negative effect on the world.

      1. He has already made it clear that he does not want to “revisit any arguments.” You can’t reason someone out of a position they didn’t reason themselves into.

    2. YES! They should only do this with humans!

      …oh wait, they have… turns out most of them enjoyed it…

      Dude, get it! Most fish that are being kept by humans are not so lucky to get to fly in an aircraft, they are just killed and eaten. Or overfed by children who care too much. Or starved by lazy children. Or flushed down the toilet by children who take “Finding Nemo” too serious.

      I’m all for not dissecting sedated  cats and then using their still-beating heart to replace their blood by formalin in anatomy class. I’m all for not testing anything on animals that can be tested otherwise, and all against killing animals for cosmetics or whatnot. _That_ is in fact disgusting.
      … but this is trivial. The fish gets a rollercoaster ride and that’s it. This is more in the “letting the neighbour’s kid play with your cat” territory. If you can’t see the difference, you might want to readjust your perspective.

      1. Just btw, did you you know the experimenters used to get drugged to be allowed on these flights with amphetamines and Scopolamine derivatives at the same time? Most of them enjoyed this as well…

        And, of course, you are completely right about about the readjustment of perspective.

  15. I believe the ESA has run student experiment flights like NASA’s Zero Gravity Student Flight Opportunity Program. Having done that twice, I feel comfortable admitting that the experiments are not always of the absolute highest scientific value. This could be along a similar vein. (Though a working freefall aquaponics system would be damned valuable to any long duration deep space mission. Working out some of the basic feasibility issues would actually make a pretty great little project.)

  16. Lots of Germans are translating the narrator’s comments, but nobody comments on how artificial and terrible he sounds. The terribleness of his reading skills completely and utterly distracted me from the goldfish it is just that bad. Is that normal for N24? I thought at first it might be some easy language German program or maybe the narrator doesn’t speak the language and is just reading off of a slip of paper. I am confused that nobody else was compelled to point that out.

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