Researchers at the National Institute of Polar Research in Tokyo have rehydrated and revived a tardigrade that had been frozen since 1983.
Two tardigrades named Sleeping Beauty (SB)-1, SB-2 and one tardigrade egg named SB-3 were collected from a frozen moss sample taken in Antarctica and was stored at −20 °C for 30.5 years. In 2014, the moss sample was thawed out at 3 °C for 24 hours, placed into a Petri dish where water was added, and soaked for a further 24 hours. The individual tardigrades were then retrieved using a pipette under a dissecting microscope.
While tardigrade SB-2 had died 20 days after rehydration, SB-1 managed to fully recover and began reproducing. Tardigrade SB-1 showed movement in its 4th pair of legs on the first day after rehydration and by day 5, slow twisting of the body including the movement of the 1st and 2nd pair of legs had been detected. On day 6, it attempted to lift itself and by day 9, it had started slowly crawling on the agar surface of the culture well. It began eating chlorella provided by the scientists on day 13 and most remarkably, it began developing eggs in its ovaries on day 21. Tardigrade SB-1 had laid a total of 19 eggs by day 45, 14 of which successfully hatched.
As for the tardigrade egg SB-3, it successfully hatched 6 days after rehydration and layed a total of 15 eggs before dying on day 32. Out of the 15 eggs, 7 hatched.
To learn more about this study, click the link below.
https://www.sciencedirect.com/science/article/pii/S0011224015300134
Footage courtesy of Megumu Tsujimoto
