Water bears revive after 30 years of hibernation.

Japanese scientists have announced that they have revived a microorganism called a tardigrade (water bear) after it had been trapped in ice for 30 years.

A tardigrade seen under a microscope. Photo: BBC

This microorganism, scientifically known as Acutuncus antarcticus, belongs to the Tardigrada phylum and is commonly found in icy environments covered with moss or lichen, feeding on plant cells in Antarctica.

Microorganisms belonging to the phylum Tardigrada are commonly known as "water bears." Their name comes from their plump appearance, which closely resembles a tiny bear under a microscope. Adults are 1.5 mm long, with the smallest measuring less than 0.1 mm. Newly hatched specimens can be smaller than 0.05 mm.

According to Asahi Simbun, research into reviving microorganisms paves the way for unraveling the mysteries of their long-term survival in the harsh, icy conditions of Antarctica.

A report published on January 14th by the National Institute of Polar Research (NIPR) in Tokyo stated 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 cryopreservation at minus 20 degrees Celsius.

In May 2014, thawed ice samples revealed two microorganisms, named SB-1 and SB-2 (short for Sleeping Beauty), measuring approximately 0.3 mm, beginning to revive and move in the water.

SB-1 remained healthy after 23 days of recovery and laid 19 eggs, 14 of which hatched successfully; while SB-2 died after 20 days due to insufficient algae intake.

According to Russia Today, scientists say that Tardigrada species can survive in extremely harsh environmental conditions, such as in the deep sea or on snow-covered mountain peaks. In freezing conditions, they enter a state called cryptobiosis, in which their bodies cease metabolism and show no signs of life.

The research results, published in the journal Cryobiology, indicate that the revival of Acutuncus antarcticus is a new record, as a previous specimen of the Tardigrada microorganism was found to have survived in a frozen state for eight years. However, Acutuncus antarcticus has not yet surpassed the record of 39 years of survival in a frozen state held by a nematode worm.

According to VnExpress