top of page
  • Sara Thompson

Tardigrades: Tiny, but Tough

By Sara Thompson

Image credit are Elham Schokraie, Uwe Warnken, Agnes Hotz-Wagenblatt, Markus A. Grohme, Steffen Hengherr, et al. Image obtained from Wikimedia Commons,

Special to the Enterprise

Tardigrades, moss piglets, or water bears, no matter what you call them, all these terms refer to the same animal. First named “little water bears” by Johann August Ephraim Goeze in 1773, because their movement was reminiscent of the large mammal. A few short years later, in 1777, they were renamed tardigrades, meaning “slow-moving” in Latin, and this has become their recognized scientific name.

Tardigrades are tiny. Their average size is around half of a millimeter, with the largest on record being 1.5 millimeters long. Although small, they can be viewed under low magnification on microscopes, making them a fun critter to find for budding scientists. The most common places to find tardigrades are in mosses and lichens. Their round shape and tendency to be found in moss gave them the nickname of “moss piglet”. However, moss is not the only place where tardigrades can be found. They have been found in the coldest parts of the arctic, the steamiest hot springs, the tallest mountains, and the deepest parts of the ocean.

Despite living in such extreme places, tardigrades are not considered ‘extremophiles’ because they are not specifically adapted to those areas but are just able to withstand most any environments. Tardigrades can also withstand extreme dehydration. Their bodies curl up and their bodily processes slow down to a point of almost death. This process is called cryptobiosis and tardigrades can survive decades in this state. Then when they are rehydrated, they are active again in a few minutes as if nothing had happened. Tardigrades have also survived the vacuum and radiation of space.

Tardigrades, moss piglet, or water bears, no matter which name you call these little critters, remember that they may be tiny, but are very tough. Next time you collect some moss or other damp material, check under a microscope, you may just see one of these wonderful creatures.

Explorit's coming events:

• Explorit is open Fridays from 1-4pm and Saturday and Sundays from 10am-2pm. The current exhibit is “Our WILD World”. Admission is $5 per person, free for Explorit Members and those aged 2 and under.

• Join us for a Spring Eggtravaganza March 23-24! Celebrate the Spring Equinox, discover eggs and animals that hatch from eggs, including birds, reptiles, and monotremes. Sponsored by Kaotic Mythicals, explore museum quality specimens of a variety of eggs, skulls, mounted specimens, and more. Take a family photo with props, meet live reptiles up close, and special themed crafts and demonstrations. Included with regular Explorit Admission, 10am-2pm.

• Solar Viewing with the Davis Astronomy club on Saturday, March 23 from 10am-2pm.

• Summer Science Camps are back for 2024! Registration begins on March 15 at noon, $185 for Members, $210 for Non-Members. More information and registration can be found at

• Now is a great time to donate and help Explorit continue to educate and inspire the scientists of tomorrow:

• A Membership to Explorit grants the recipient free visits to Explorit’s regular public hours, discounts on events, summer camps and workshops, and gives you ASTC benefits to visit other museums throughout the world. To purchase or for more information visit or call Explorit at 530-756-0191.

• Only a few dates left for Spring school programming so call soon for reservations. Fall program availability is open. For more information, please visit


bottom of page