Tardigrades: the Great “Bear” Hunt

Sam G. (Grade 6)

Editor’s note: Two middle school science fair winners from Alta Vista School will represent AVS at the Bay Area Science Fair at the Academy of sciences on February 24th, 2016 – Sam G. and Ian G. Ian’s project looked at violin mutes.


Sam is fascinated by tardigrades. No, that’s not something from Dr. Who. It’s his science project for the middle school science fair at AVS. The title is a bit mysterious: “Tardigrades: the Great “Bear” Hunt.” Also known as “water bears,” tardigrades are microscopic creatures that consist of a couple thousand cells.

When you look at a picture of a tardigrade, it looks, well, like an alien that has been living in a cave for thousands of years. They are some of nature’s toughest creations, virtually impossible to kill. A tardigrade can go into cryptobiosis , a kind of hibernation, when not in water. “When it’s in cryptobiosis, it’s very, very tough. It can withstand almost anything. It can withstand a thousand times the radiation that will kill a human. It’s one of the few multi-celled animals that’s able to survive the vacuum of space.” But tardigrades have yet to be found on other planets.

Sam first heard about tardigrades from Neil Degrasse Tyson in the PBS series Cosmos. He decided to research them more and sampled different places around San Francisco and the Bay Area: his backyard, his frontyard, Stern Grove, Muir Woods. “There are more than 900 kinds of tardigrades,” Sam tells me. He found eleven kinds. “I’m sure there’s some here at school. My first sample came from under my stairway (at home).” Sam sampled moss and lichen and put the tardigrades under his microscope at AVS. “If you had a tardigrade alone on a black canvas, you could see it as a little, white speck of dust.”

How are the different kinds unique? “Mainly, what makes one tardigrade different from another is their claws. Some tardigrades have a soft skin, and they mainly eat moss and plants and things. Some predator tardigrades will eat other tardigrades and other organisms, like parameciums and things.” Good news is, they don’t bother humans.

Tardigrades are found all over the world, but they will hibernate when conditions are inclement. “Tardigrades are probably very happy now, because they like water and live in moss and lots of moss is growing, because it’s raining a lot,” Sam says, referring to the rain that everyone hopes will end California’s drought.

Sam’s science project next year? “We’re thinking of trying to keep a colony of tardigrades, taking a specific type and studying it. I love that they are super-tough.”