Tardigrades are among the weirdest of animals.
Also known as "water bears" or "moss piglets," the 1,300 recognized species are the only members of phylum Tardigrada, a term that means "slow stepper" for their somewhat waddling gait. German zoologist Johann August Ephraim Goeze first described the tardigrades in 1773. They live in seas, in fresh water, and on land.
Tardigrades are famous for hiding when environmental conditions turn treacherous, only to emerge years or even decades later unscathed. They survive extremes of dehydration, radiation, and great ranges of temperature and pressure. For example, tardigrades live under almost 6,000 times the pressure of the Earth's atmosphere at sea level. They're called "extremotolerant."
They live pretty much everywhere, from mountain peaks to beneath glaciers and oceans and lakes, under the leaf carpet of forests, along logs and stones. To see them, collect a bit of lichen or moss and soak it overnight, then squeeze it onto a light microscope slide.
We could learn a lot about how tardigrades survive in the extremes. Now a report in PLoS Genetics from researchers at the University of Tokyo describes use of the gene-editing tool CRISPR to better understand the unusual traits of the just-barely-visible tardigrades.
Unusual Anatomy and Physiology Enables Survival
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