Liquid nitrogen is nitrogen in a liquid state at an extremely low temperature (around −200 °C). On the other hand, Leech is such a worm that can survive in super adverse weather or temperature. But in liquid nitrogen, it’s even impossible for a Leech to survive for long time. And the very interesting thing is, lately, researches have discovered a special Leech that can survive 24 hours while submerged in liquid nitrogen!
Leeches are segmented worms but they differ from other oligochaetes in significant ways. Leeches do not have bristles and the external segmentation of their bodies does not correspond with the internal segmentation of their organs. Their bodies are much more solid. They have two suckers, one at each end. Until now, researcher have discovered almost 700 species of leeches, of which some 100 are marine, 90 terrestrial and the remainder freshwater taxa. But lately, out of those discovered Leeches, researchers have identified a very special leech known as Ozobranchus jantseanus, that can survive 24 hours in liquid nitrogen!
Ozobranchus jantseanus is a small parasitic Leech of freshwater turtles in East Asia. At first glance, researchers found nothing special in this Leech. But when they submerged the Leech into a vat of liquid nitrogen, they became surprised. Researchers thought that the Leech would die in no time in liquid nitrogen, but it survived for 24 hours!
That’s really astonishing because most creatures can’t survive for very long below water’s freezing point of 32°F (0°C). And at atmospheric pressure, liquid nitrogen boils at −196 °C (77 K; −321 °F) and is a cryogenic fluid that can cause rapid freezing on contact with living tissue. Until now, two species have been found that can survive in liquid nitrogen. The two species are water bears and the larvae of one type of drosophilid fly. The most interesting thing is neither of them couldn’t survive for no more than 1 hour.
However, researchers have also discovered that every single Leech placed in -130°F (-90°C) temperature can survive for 9 months. Some of the Leeches survived at this temperature for 32 months, or more than 2.5 years.
A report of scientists regarding this matter have been published on Jan 22 in PLOS ONE. In that report, scientists have mentioned that they don’t know how Ozobranchus jantseanus was able to withstand at such extreme cold temperature.