CRYO: Nature's little cryonauts

Eugene Leitl (eugene.leitl@lrz.uni-muenchen.de)
Wed, 4 Aug 1999 15:56:29 -0700 (PDT)

Jeff Fabijanic writes:
> I consider that 'frozen',
> whether or not all the liquid in their bodies was crystalized or simply in
> a colloid 'slush'. I have had people question whether Lucky-fish too, was

Sorry, commonly the word frozen is used to denote a liquid system totally undergone phase transition. I may partly freeze an alcohol or salt solution into a sludge (=water ice crystals in unfrozen solution), but this is not homogenous ice. (The process of supercooling a liquid until it turns into a (meta)stable glass is called vitrification, btw).

Neither occurs with freeze-hardy higher animals. They all die if cooled deep enough for the residual liquid to freeze. Suda's experiment won't work if you try it with liquid nitrogen.

> simply quiescent in the unfrozen muddy silt at the bottom of my pond. Let
> me assure you, on my very exposed deck, up here in New England, the fish
> pond (which is a 40gal tub supported on blocks with no insulating material
> under it), with only several gallons of water in it (ie <2 inch layer),
> freezes completely after a few days of <10F weather. After 60 days of
> continuous frost, it is *rock* solid frozen. And that little fish, maybe

                           ^^^^^^^^^^^^^^^^^^^ 
That's how it appears superficially. ~260 K is not cold enough by far for that. Try dry ice or nitrogen, and then rewarm the fish. Surprise!

> 2-3 oz at the time (much larger now), was assuredly frozen solid as well.
> There was even a fishy-shaped cavity on a couple pieces of the ice slab
> that I removed.

All this has very little to do with the internal state of the organism. I may freeze an animal heart "rock solid" by briefly submerging it into liquid nitrogen. It will even resume beating if rewarmed. Unfortunately, "rock solid" only refers to the outer shell.

> It may say in cryo textbooks that higher animals don't freeze, but having a
> brother who personally discovered several new species of insect in NJ in
> the 1980s, I have a good appreciation for the incompleteness of our
> official understanding of the natural world.

Cryobiology might be incomplete, but it is not *that* incomplete.