Tardigrada
Hypsibius dujardini, scanning electron micrograph © Bob Goldstein
Tardigrades are microscopic creatures ranging from 0.1mm to 1.5mm in length.
Tardigrades have a barrel shaped body with:
- 4 segments
- 4 pairs of unjointed legs with claws
Extreme conditions
Tardigrades are known as polyextremophiles. That is, they are adapted to living in extreme conditions.
They have been found to survive:
- 10 years with no water
- very low and very high temperatures
- extremely low and high pressures, as found in a vacuum or in the deepest ocean trench
- lethal doses of radiation
- high levels of environmental toxins
About the name
The name Tardigrada literally means ‘slow walker’. They are also known as 'water bears' as their stride is reminiscent of a walking bear.