Thursday, February 9, 2017

Water Bears: The (Almost) Indestructible Animal

Water Bears: The (Almost) Indestructible Animal

Tardigrades, also known as "water bears", "water" for the environment they are typically found in and "bear" for the striking similarity between the way they move and a bear walks are one of nature's most interesting animals. Other than blurring the line between adorable and repulsive, the tardigrade proves to be a true evolutionary marvel. These are not your average everyday water-dwelling organisms, these are among the most resilient animals found on Earth. Let me break it down for you.

The tardigrade has been found to survive:
Temperatures ranging from −272 °C (~1 K, −458 °F) to 151 °C (304 °F), although only for a few minutes at these temperatures. At -20 °C, it has been able to survive for 30 years.
Atmospheric pressures ranging from the vacuum of space to more than six times the pressure at the bottom of the Mariana Trench (6,000 atm).
Severe dehydration, being able to survive for 10 years after having a body composition of 3% water. This occurs in extreme cold conditions, so that when freezing does occur, the expanding water does not rip its body apart.
Extreme levels of radiation, roughly 1000 times more radiation than other animals. This is due to their above average ability to repair damaged DNA.

In the eyes of some scientists, the most impressive attribute of the tardigrade is their resistance to radiation. Researchers took notice of their DNA's tolerance to radioactivity and decided to perform an experiment using human cultured cells and tardigrade-unique DNA-associating protein. What they found was that the protein suppresses X-ray-induced DNA damage by 40% and improves tolerance to radioactivity. This is a big deal because these findings could lead to a source of protection genes and mechanisms to benefit the human race.

Thanks tardigrades, you cute-ish ugly-ish creatures.

Posted by Ross Cavalieri (1)



  1. Tardigrades are amazing organisms! I wonder if their ability to survive at such extreme temperatures and pressures is due to their above average DNA repair mechanisms? I read online that the tardigrade only has significant DNA repair mechanisms when it is hydrated. Also, since they are able to survive in almost all conditions on Earth (even in space), what would be their ideal habitat?

    Posted by Sierra Tyrol

    1. Thanks for your interest in my post Sierra! I'm glad that it left you asking questions. Regarding your last question about the tardigrade's ideal habitat, there is actually a definitive answer. Tardigrades, although able to survive in such extreme environments, cannot thrive in them. This is why many scientists do not consider them to be extremophiles, despite their ability to exist in harsh conditions. Their ideal habitat is one that is wet and warm, as they are often found on mosses.

      Posted by Ross Cavalieri

  2. After reading your post, I went on a bit of a Tardigrades research binge. The implications of this unique organism could be astronomical for the human species. With enough research, their protein Dsup, which allows their DNA to withstand great amounts of radiation could be used to enhance many facets of human life. It could be possible for humans to better withstand radiation treatments, it could protect workers at nuclear plants and even allow us to grow crops in extreme environments. One scientist at Chapel Hill, Bob Goldstein, made a great point that this is probably one of many discoveries to come, since the Tardigrades can withstand many extremes and therefore must have many mechanisms to protect themselves. I am excited to see where the unique qualities of this aquatic microorganism could take humanity in the near future.

    Posted by Jenna Lansbury

    1. Jenna, I'm glad my post inspired you to go out and research more about the tardigrade! It's honestly such an intriguing organism and should be researched more. Like you said, resistance to radiation could improve much more than just human lives, it could improve the lives of any organism.

      Posted by Ross Cavalieri

  3. Like Jenna and Sierra, I also was more than intrigued with Tardigrades, so I researched it a little bit more. It seems, although they are capable of surviving for 30 years without food or water, they cannot fully function during this time. It almost seems like they enter a phase of hibernation of some sort, and only after they rehydrate and forage, can they truly live and reproduce. I wonder what genes make such hibernation possible? Could it be an extreme version of what other animals go through during long winters?

    Posted by Caitlin Lohr

  4. Sounds like some pretty impressive animals. It's crazy that there are probably thousands of unknown creates that can live in such a cold environment and high pressures. Animals have amazingly complex bodies, to be able to adapt to such extreme conditions you wouldn't think possible. Makes me wonder how far evolution can really go! (although, there are always its limitations)

    I agree, that they are ugly-ish. Not sure about the cute-ish...hahaha

    Posted by Natalie Nou

  5. I remember briefly learning about water bears in one of the experiments in the intro to bio lab. I think it’s so fascinating that we have so much to learn from such a small organism. The fact they can live pretty much anywhere shows just how temperamental they are. I think one of the most interesting things about them is that they can survive in space. Their ability to repair DNA could definitely be beneficial to medicine if that ability is figured out.

    Posted by Hannah Jordan

  6. It’s amazing how some microorganisms can survive is such extreme temperatures! I learned about some of these organisms in my microbiology class last year but I don’t think I’ve ever heard of Tardigrades so I found this post to be really interesting to read! It’s amazing how these tiny organisms can survive in unimaginable conditions. I found it super fascinating that these organisms can make proteins that are resistant to radiation and the fact that scientists are exploiting these proteins to potentially help protect our own DNA from being damaged by radiation.
    Posted by: Katie Kossack