Tardigrade transition. The tardigrade of the species Milnesium tardigradum is around 1 mm in size and can be found in a diversity of habitats. In the anhydrobiotic tun state (right), tardigrades show remarkable tolerance against physical extremes. During the transition from an active into an inactive form (here by dehydration) and back (rehydration), metabolites are measured in a time series by GC-MS. The aim of the integrated analysis is to trace changes in tardigrade metabolism and identify pathways responsible for their extreme resistance against physical stress.