Water bear revives after 30 years of hibernation

Japanese scientists announced that they have revived a microorganism called a tardigrade after 30 years trapped in ice.

Water bear seen under a microscope. Photo: BBC

This microorganism has the scientific name Acutuncus antarcticus, belongs to the Tardigrada phylum, is often found in icy environments covered with moss or lichen and eats plant cells in Antarctica.

Microorganisms in the phylum Tardigrada are commonly known as “water bears.” Their name comes from their plump appearance, which resembles a tiny bear under a microscope. Adults are about 1.5 mm long, with the smallest measuring less than 0.1 mm. Hatchlings can be as small as 0.05 mm.

According to Asahi Simbun, research on reviving microorganisms paves the way to deciphering the mysteries of its long-term survival in the harsh icy conditions of Antarctica.

A report released by the National Institute of Polar Research (NIPR) in Tokyo on January 14 said that in November 1983, a Japanese expedition collected samples of moss-covered ice containing the microorganism Acutuncus antarcticus and brought them back to NIPR for freezing at minus 20 degrees Celsius.

In May 2014, thawed ice samples showed that two microorganisms named SB-1 and SB-2 (short for Sleeping Beauty) measuring about 0.3 mm in size began to revive and move in the water.

SB-1 was healthy after 23 days of revival and laid 19 eggs, of which 14 successfully hatched; while SB-2 died after 20 days due to not eating enough algae.

According to Russia Today, scientists say Tardigrada species can survive in very harsh environmental conditions, such as deep in the sea or on snow-capped mountain peaks. In freezing conditions, they fall into a state called cryptobiosis, when their body stops its metabolism and shows no signs of life.

The research results published in the journal Cryobiology said that the revival of Acutuncus antarcticus is a new record, because previously a microorganism specimen of the Tardigrada was discovered to have existed in a frozen state for 8 years. However, Acutuncus antarcticus still cannot beat the record of survival in a frozen state of 39 years of a nematode worm.

According to VnExpress