WOKEN AFTER
A 31-YEAR
SLEEP
A splash of water, a
petri dish and a
few days was all it
took for scientists
at Japan’s
National Institute
for Polar Research
(NIPR) to revive a
pair of tardigrades
that had been frozen
for more than three
decades. The microscopic
creatures, commonly known as water
bears, were recovered from a moss
sample collected in Antarctica in
November 1983. The sample was
stored at -20°C in order to preserve it
until it was finally defrosted in May last
year, when the presence of the
tardigrades, nicknamed ‘Sleeping
Beauty 1’ and ‘Sleeping Beauty 2’, was
spotted.
“Sleeping Beauty 1 first showed
slight movement in its four th pair of
legs on the first day after rehydration,”
reported the NIPR scientists. “Sleeping
Beauty 1 started to slowly crawl on the
surface of the petri dish on day nine
and started to eat the algal food
provided on day 13.”
Sleeping Beauty 2 only survived for
20 days after being revived, but
Sleeping Beauty 1 was able to begin
developing and laying eggs within
three weeks.
The robust creatures were able to
endure the prolonged cold storage by
entering a state of extreme hibernation
called cytobiosis. A tardigrade’s
metabolism slows to just 0.01 per cent of
its normal rate while in this state. It also
dehydrates itself and replaces water in
its cells with the sugar glycerol to guard
against cell damage during freezing.
It’s hoped that investigating cytobiosis
in the tardigrade will lead to
improvements in our ability to preserve
the cell integrity of frozen tissue samples.YEAR
EP
water, a
nd a
as all it
entistsute
rce
chNATURE’S TOUGHEST COOKIE
Bear Grylls and cockroaches have built reputations on their ability to survive in harsh conditions, but they’re
lightweights compared to tardigrades. Despite growing to a maximum of 1.5mm in length, these tiny
creatures are phenomenally tough
SPACE ADVENTURERS
Dehydrated tardigrades were exposed to the
vacuum of space while aboard a European Space
Agency satellite in 2007. Many of the creatures were
successfully rehydrated and brought back to life after
returning to Earth 10 days later.
SEA FARERS
In June 2000, various species of tardigrade were
discovered living in the Gulf of Mexico at depths
between 625m and 3,159m. Studies have shown the
creatures are able to withstand pressures
of up to 87,022psi.
TARDIGR ADESPOLAR EXPLORERS
Absolute zero holds no fear for tardigrades. Back
in the 1920s, Gilbert Franz Rahm demonstrated
this by plunging them into liquid helium
at -272°C for almost half an hour. He also
submerged another group in water heated to
151°C for 15 minutes.NUCLEAR SURVIVORS
Tardigrades are able to tolerate doses of ionising
radiation 1,000 times higher than what would be
lethal for a human. They can even produce viable
offspring after exposure.BIOLOGY