• More than 1,000 species, measuring 0.05-1.2 millimetres

• Also called water 'bears' because of how they , and moss piglets

Physical appearance

• A , rounded body with four pairs of legs
• Claws or suction  used for gripping

• No organs for breathing

• A body fluid that transports blood and 
• A mouth resembling a , containing teeth called stylets

Habitat

• Often found on lake beds or growing vegetation

• Able to withstand extremely high and low 

Cryptobiosis

• In dry surroundings, they form a ball known as a tun.

• Their metabolism becomes far slower than normal.

• A particular  prevents harm to their DNA.
• Experiments are testing how long they remain alive in .

Feeding

• Obtain liquid from sources such as moss and 

• Some species consume other tardigrades

Conservation status

• They are not classified as .