Is a state in which metabolic activities come to a reversible standstill. It is truly a death-like state; most organisms die by a cessation of metabolism. The most common type of cryptobiosis studied in tardigrades is anhydrobiosis
Tardigrades can survive dry periods by curling up into a little ball called a tun. Tun formation requires metabolism and synthesis of a protective sugar known as trehalose, which moves into the cells and replaces lost water. Revival typically takes a few hours, depending on how long the tardigrade has been in the cryptobiotic state.