Tardigrades and anhydrobiosis

Tardigrades, sometimes known as water bears or moss piglets, live in mosses, algae and freshwater on Mount Erebus. Acutuncus antarcticus is the most abundant tardigrade species in Antarctica.

Tardigrades are well known for surviving in extremely harsh environments. They can stop all measurable metabolic processes until environmental conditions become favourable again. This protects them from both desiccation and freezing. Watch a tardigrade move from an active state to a dormant state in this video.

Freshwater is scarce so tardigrades living on mosses or lichens on Mount Erebus are only active when they are covered by a thin film of water.

Image from Schokraie E, Warnken U, Hotz-Wagenblatt A, Grohme MA, Hengherr S, et al. (2012) Comparative proteome analysis of Milnesium tardigradum in early embryonic state versus adults in active and anhydrobiotic state. PLoS ONE 7(9): e45682. doi:10.1371/journal.pone.0045682