Medaka Fish in Space Station—An Aquarium That is Out of This World

Albert B Ulrich III Fish News, Saltwater Fish Leave a Comment

image of medaka fish in spaceMedaka Fish in Space Station—An Aquarium That is Out of This World

Thirty-two Japanese fish called Medaka fish, Oryzias latipes, were transferred up to the international space station on October 25th. It took the fish (and the astronauts traveling with them) two days to reach the Space Station, which orbits 254 miles above the Earth.


Medaka fish or Japanese killifish in an aquarium in the space station

According to NASA’s website, scientists are planning to look at how radiation, gravity and life as a fish in space impacts development of the fish embryos and muscle and bone loss (called atrophy for muscles and degradation for bones).

The researchers chose Medaka fish for several reasons:

  • The Medaka fish’s genome (half the size of the zebrafish genome) has been fully sequenced
  • Medaka fish breed quickly and easily in low-gravity environments
  • Medaka fish have a short life-cycle (generation time is 7 weeks), which means that multiple generations of fish can be born over the span of the experiment—which allows scientists to examine the effects of space on multiple generations of fish
  • Medaka fish have transparent skin, allowing the scientists to peer inside their bodies

You may be wondering how in the world you fill an aquarium with water in a zero (or low) gravity space station. Well it starts with an out-of-this world aquarium. Check out the image below from NASA’s website:

medaka fish in aquarium on space station

The aquarium has a space-age biological filter that should keep the aquarium clean for 90 days. The aquarium is equipped with an auto-feeder, LED lights, a webcam and a closed-water circulation system.

What is a Medaka fish? The Latin name is Oryzias latipes, and is also known as the Japanese killifish that has been kept as an aquarium fish in Japan since the 17th century, according to Wikipedia.


The Medaka fish is the first vertebrate (known by humans) to have mated in orbit (source Wikipedia).


Will the generations of fish born aboard the space station have genetic variability when compared with their earth-bound brothers and sisters? Will the profile and make-up of their bodies change in any way due to the relative weightlessness of life aboard the space station? I’m seriously jealous of their fish room. It puts mine to shame.


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Albert B Ulrich IIIMedaka Fish in Space Station—An Aquarium That is Out of This World

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