Water Bears Grin and Bear It


Tardigrades might be tiny, but they’re mighty mysterious. Also known as water bears (or my personal favorite, moss piglets), the eight-legged micro-beasties can survive basically anything, including years of dehydration, massive doses of radiation and the vacuum of space. (Washington Post)

Tardigrades are one of the most frequently found microorganisms at bioblitzes—are they the cutest? You be the judge.

Teachers, scroll down for a quick list of key resources in our Teachers Toolkit. It’s a really good one today.

Toughest? Cutest? Be sure to scroll and vote in today’s super-scientific polls.

Cute? Creepy? This beautiful image of a tardigrade was taken with a scanning microscope by Dr. Diane Nelson, a tardigrade researcher who works in Great Smoky Mountains National Park. Click here for a great lesson plan on tardigrades from the good folks at the National Park Service.
Photograph by Diane Nelson, courtesy National Park Service

Discussion Ideas



  • Why does the Washington Post describe the tardigrade as nearly invincible?
    • Tardigrades have lived on Earth for more than 500 million years.
    • According to the BBC, “The little critters seem adept at living in some of the harshest regions of Earth. They have been discovered 5546m (18,196ft) up a mountain in the Himalayas, in Japanese hot springs, at the bottom of the ocean and in Antarctica. They can withstand huge amounts of radiation, being heated to 150 °C, and being frozen almost to absolute zero.”
    • Tardigrades can survive outside Earth’s atmosphere—in the bare vacuum of space.
    • Let Neil deGrasse Tyson and his beautiful baritone voice tell you about it.


  • An “extremophile” is defined as a “microbe that is adapted to survive in very harsh environments, such as freezing or boiling water.” Do you think tardigrades are extremophiles?
    • No! Gotcha. The keyword there is “adapted.”
    • Tardigrades are generally not considered extremophiles because the little critters are not specifically adapted to live in extreme environments. (In other words, their chances of dying increases the longer they are exposed to extreme heat, cold, or pressure.) So, they’re not built for life in the extremes; they’re just that tough.


  • Why does at least one scientist say the newest tardigrade study is “highly interesting for medicine”?
    • Researchers identified a protein that contributes to tardigrade toughness. The protein “helps protect tardigrade DNA from the dangerous side effects of radiation exposure and repair any damage that does occur. When they manipulated human cells to make them produce the tardigrade protein, those cell cultures experienced some 40 percent less damage from X-ray exposure than normal cells.”
    • “It could be helpful for space flight, radiotherapy and radiation workers in the far future,” says the study’s lead author.
    • Tiny animals? Radiation exposure? Sounds familiar. Tardigrade Man, Tardigrade Man, does whatever a tardigrade can …



Washington Post: Water bears’ latest superpower: Proteins that protect them from radiation

National Park Service: Water Bears, Rotifers and Nematodes – Oh My! Middle School

Microbial Life Educational Resources: Tardigrades (Water Bears)

American Scientist: These ambling, eight-legged microscopic “bears of the moss” are cute, ubiquitous, all but indestructible and a model organism for education

BBC Earth: Tardigrades Return from the Dead

5 thoughts on “Water Bears Grin and Bear It

  1. This is awesome. I am going to make a shirt dedicated to tardigrades on hippiecamel.com

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