Don't call it a comeback — just call it "being cyrogenically unfrozen" — sort of.
A tardigrade (i.e., an eight-legged micro-animal also known as a water bear or a moss piglet) has been defrosted after three decades of being suspended in a — for lack of a better term — chilly state. Even crazier? According to a team of scientists, it's come back to life.
In terms of technicalities, the reanimated water bear wasn't exactly cryogenically frozen to begin with; the proper term is actual "cryobiotically frozen," meaning that natural conditions like the sub-freezing temperatures in the Antarctic — where it was recovered, along with another sample, by scientists in 1983 — are responsible for its formerly-suspended state, not humans. The water bears were then kept in -20 degree Celsius temperatures to keep them on permafrost lockdown for future testing.
Fast-forward to 2014, where a group of researchers at Japan's National Institute of Polar Research were able to successfully warm one of the samples by placing them both in a more temperate environment. The sample that survived was back to fully-functional in just under the span of one week, and gave birth to a bevvy of offspring in two.
According to the study, published in the scientific journal Cryobiology, reanimation has been studied in other micro-animals like nematodes and rotifers, but this marks the first time a water bear has reanimated over such a lengthy stretch of time — the last record to be held was nine years.
"One of the two resuscitated individuals and the hatchling successfully reproduced repeatedly after their recovery from long-term cryptobiosis," the researchers wrote. "This considerable extension of the known length of long-term survival of tardigrades recorded in our study is interpreted as being associated with the minimum oxidative damage likely to have resulted from storage under stable frozen conditions. The long recovery times of the revived tardigrades observed is suggestive of the requirement for repair of damage accrued over 30 years of cryptobiosis."
For those in the know, it's not surprising that the tardigrade could survive these Antarctic conditions in a suspended state for so long: the water bear is also the only known animal, micro or otherwise, that can survive in outer space-like conditions.
Learn more about the tardigrade in the video clip below.
Photo: Katexic Publications | Flickr