I've been interested in the Japanese experiment on the ISS involving raising fish in space, but in all my reading the results seem a bit ambiguous/conflicting (depending on source).

What are the results?

- Can unmodified fish be successfully raised in space? (If no, can the (currently) genetically modified variants be successfully raised in space?)

From what I read, some credible sources said no because the fish rapidly consumed their own skeletons and their offspring didn't form them at all and died as a result.... others said they simply lived glancing over that subject altogether.

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    $\begingroup$ From what I read A link to what you read would be helpful. $\endgroup$
    – Machavity
    Jul 17, 2018 at 13:00
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    $\begingroup$ Please show links to what you have read rather than multiple people having to repeat the same search independently. The more work and help you put into the question, the more help you may receive in return. By the way, typing "fish" into the search box in this site returns 37 entries! Have you checked to see what's here already? If you find something relevant here, add a link to that to your question as well! $\endgroup$
    – uhoh
    Jul 17, 2018 at 13:27
  • $\begingroup$ Hmm... It would be really neat to see a fish float by in a sphere of water in 0g, makes me wonder if the fish could still propel itself through the water efficiently given enough space. $\endgroup$ Jul 17, 2018 at 16:13
  • $\begingroup$ @MagicOctopusUrn The fish could still propel itself through the water, see my answer. $\endgroup$
    – called2voyage
    Jul 23, 2018 at 19:19
  • $\begingroup$ If you are interested, a previous experiment on the Shuttle showed that it was possible to bring the Medaka fishes for two weeks into space, mate there, create an offspring and then when the offspring was brought back to Earth it developed normally and also had a third generation on Earth. jstage.jst.go.jp/article/bss/8/4/8_4_231/_pdf/-char/en $\endgroup$
    – BlueCoder
    Aug 23, 2018 at 8:59

1 Answer 1


In many ways, medaka fish were able to adapt to the microgravity environment:

Medaka fish were filmed for abnormal behaviors to consider a physiological change under microgravity. The movies showed that the fish became accustomed to life under microgravity by displaying unique behaviors such as upside-down, vertical, and tight-circle swimming. In addition, we found that the mating behavior at day 33 under microgravity was not different from that on the earth, indicating that the medaka fish had adapted to their microgravity environment.

However, chronic stress and reduced activity still resulted in impaired physiological function.

For more detailed analyses, I suggest follow up questions relating to specific studies and/or aspects of fish biology.


  • $\begingroup$ That doesnt answer my question which was "what was the viability of their offspring". Sure they engaged in mating behavior but that tells me nothing about if their offspring survived or if they even had them. Moreover, skimming through your article seems to only cover 60 days of the experiment from being born on the ground and brought to space. $\endgroup$
    – anon
    Jul 23, 2018 at 19:50
  • $\begingroup$ @anon As far as I can tell, the offspring were not produced in space and the studies performed did not include an examination of viability. $\endgroup$
    – called2voyage
    Jul 23, 2018 at 20:04
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    $\begingroup$ @anon Your question could stand to be refined as the title merely asks "what were the results" and the body asks if they can be "raised" which is ambiguous. My answer addresses whether or not fish can adapt to the microgravity environment which covers an aspect of raising fish. $\endgroup$
    – called2voyage
    Jul 23, 2018 at 20:06
  • $\begingroup$ @anon Also, the experiment only lasted 60 days. That is the total length. $\endgroup$
    – called2voyage
    Jul 23, 2018 at 20:13

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