Water bears

Tardigrades are microscopic creatures measuring 0.1mm to 1.2mm long. They look like chubby bears with eight legs but move very slowly – this is where the name Tardigrade comes from, it means ‘Slow walker’ When viewed under the microscope they crawl around in a clumsy manner making them a popular subject to study. They can be found living on land (especially in moss and on beach sediments) as well as in freshwater and in the sea. Most Tardigrades use a sharp straw-like mouthpiece to feed on plant sap. Some seawater Tardigrades are carnivorous and eat tiny animals such as nematodes and rotifers.

Fast Facts

Latin name: Tardigrade

Notable feature: They look like chubby bears with eight legs but move very slowly

Rarity in the UK: Rare / Common

Water bears sent to space!

Tardigrades are hardy creatures and are able to withstand extreme pressure (6000 atmospheres) and temperatures (-272oC to 151oC). The little creatures were put to the test in September 2007 when Ingermar Jonsson of Sweden’s Kristianstad University and colleagues launched two species of dried-up Tardigrades into space.

After 10 days in space – with no air, intense rays from the sun and no water the Tardigrades were rehydrated and a handful managed to survive! They are the first animals on earth known to be able to survive the harsh conditions of space.

Coming back to life!

Tardigrades have the ability to perform cryptobiosis – this is when a creature can survive difficult environmental conditions, such as freezing or lack of oxygen for a very long time. Tardigrades can dry out and survive for years without water. When water becomes available they are able to rehydrate and come back to life, all in a matter of minutes!

Travelling on the wind

Dried out Tardigrades (known as a tun) are so small and light, the wind will often pick them up like grains of dust and blow them for thousands of miles.