Little water bear

Pyrococcus furiosus (‘rushing fireball’), discovered in the Aeolian Islands in 1986, is a micro-organism that thrives at high temperatures (around 100°C) near underwater geothermal vents. Organisms able to live in conditions that would kill most things – under extremes of temperature, pressure, acidity, radiation – are known as extremophiles. Bacteria known as snottites (the etymology is bluntly Anglo-Saxon) live in caves deep underground where they feed on hydrogen sulphide. Among the largest extremophiles are half-millimetre-long eight-legged animals called tardigrades. Johann Goeze, who first described the phylum in 1773, called it kleiner Wasserbär (‘little water bear’); they’re also known as moss piglets. More than a thousand species have since been identified, found everywhere from the seabed to the peaks of the Himalayas. The oldest tardigrade fossils date from 530 million years ago. They can survive for several minutes at 150°C or near absolute zero (and for several days at −200°C); endure both a vacuum and 6000 atmospheres of pressure; and tolerate levels of radiation a thousand times higher than would kill a human being. They’ve been taken up on space shuttles, exposed to open space for ten days and survived. According to a paper by a team of German researchers published in Bioinformatics and Biology Insights last year, the ‘specific molecular pathways for stress adaptations’ in tardigrades ‘are partly conserved in other animals and their manipulation could boost stress adaptation even in human cells.’