Phylum Tardigrada

Fascinating Facts

  • Tardigrades are also known as “water bears” or “moss piglets.”
  • They have no respiratory organs, instead performing gas exchange across their entire body surface.
  • They can withstand temperatures just above absolute zero to far over the boiling point of water.
  • They can also survive the vacuum of space, pressures greater than deep sea trenches, and radiation 100x the lethal human dose.
  • They can go without food or water for years, drying out to 3% water, only to rehydrate, forage, and reproduce later.


Tardigrades are water-dwellers that live in mosses and lichens and feed on plant cells, algae, and small invertebrates.

Status in the Wild

Not yet assessed by IUCN


Found throughout the world, from the Himalayas to the deep sea, and from the polar regions to the equator.


Location in the Zoo

Invertebrates Zone of the Sculpture Learning Plaza

Animals & Exhibits