Rotifers or rotifers are microscopic multicellular organisms that live in fresh water. They are already known to withstand freezing (even in liquid nitrogen), boiling, drying and radiation. They can survive for millions of years without sex.

The humble but surprisingly hardy rotifer bdeloid has once again surprised scientists. A new study by age in permafrost excavations 24,000 years revealed living (or at least capable of regenerating) rotifers. Surviving this long in deep-freezing conditions is a new record for this species.

The researchers found that the rotifers were able to survive a relatively slow freezing process (about 45 minutes). This is important because ice crystals form inside animal cells rather slowly – a phenomenon that is often disastrous for living organisms. In fact, anyone who deals with cryopreservation desperately needs defense mechanisms against it, making the latest finding particularly important in this regard.

This is also important because rotifers are one of the hardest-to-freeze microorganisms – they have organs like the brain and gut.

Return to ecosystem

Rotifers aren’t the only living organisms to survive in permafrost or permafrost. The same researchers who made the most recent discovery found living roundworms that were about 40,000 years old, formerly in crisis. Ancient algae, seeds, viruses and bacteria also showed impressive longevity, raising legitimate concerns about whether potentially dangerous pathogens would be released from melting glaciers and permafrost.

Given that bdelloids typically only pose a threat to bacteria, algae and debris, there is little reason to worry about this particular discovery. But as key players at the bottom of the food chain, newly discovered rotifers suggest we need to think about how species perhaps invisible for thousands of years might reintegrate into modern ecosystems.

Numerous species of organisms still live in the permafrost crisis. At least at the microscopic level, it seems possible to dissolve intact micro-ecosystems (nematodes, rotifers, protists, viruses, bacteria, etc.) together. How these long-dormant species will compete or coexist with modern ecosystems is difficult to predict at this time, but it’s probably a question worth considering.