CHRISTMAS. A blowout turkey dinner and the Queen’s speech have left you
decidedly lethargic. What better time for contemplating leisure? And what more
perfect topic for such musings than His Royal Highness Prince Luigi of Savoy and
a languorous little creature known as the ice worm.
Prince Luigi was the brother of the king of Italy at the end of the last
century. He was also Duke of the Abruzzi. But most of all, he was a
self-appointed lord of leisure who spent most of his free time traipsing around
the globe, climbing mountains.
It was during a well-portered Prince Luigi expedition that one of the
earliest known records of the ice worm, Mesenchytraeus solifugus, made
it into print. In 1897, the mountaineer and his entourage were camped at
Malaspina Glacier in Alaska prior to becoming the first humans ever to scale
Mount St Elias. Before the historic climb, Prince Luigi’s personal physician, Dr
Filippo de Filippi, observed what he later recorded as “myriads of small black
ɴǰ”.
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Either Filippi was having trouble sleeping, or it was a very cloudy day,
because it is only after the sun goes down that M. solifugus (sun
avoider) make their way to the chilly surface of the glacial ice. During the
day, they crawl down microscopic cracks as deep as two metres into the dark,
frozen depths. In between those bursts of activity, the ice worm’s life is
lethargic in the extreme. It doesn’t spend a lot of time running from predators.
Nor does its prey—ice-bound algae—need much chasing down. As far as
anyone can tell, an ice worm spends its entire life doing just about nothing. It
is, without doubt, the prince of its frosty universe, eternal heir to a royal
throne of ice. Master of its moraine.
If Prince Luigi thought the spectacle of ice worms was odd, he didn’t make a
big deal of it. Nor has anyone since—only a handful of scientific papers
have been written on what is clearly a creature that raises a few questions. For
starters, how does it survive, let alone hatch out and develop on the frozen
wastes of a glacier, conditions that would kill most other species, or at very
least put them in suspended animation? And what drove it to inhabit a world so
far from that of the warm gravy that gave birth to life on Earth?
One person is trying to answer those questions. His name is Dan Shain, and
he’s a developmental biologist at Rutgers University in Camden, New Jersey. New
Jersey hasn’t seen a glacier for approximately 10 000 years, but in Shain’s lab
there is what was until recently the world’s only ice worm research facility. It
consists of a Tupperware bowl, some water, and a piece of ice that is changed
weekly.
Oh yes, and the ice worms.
Shain was on a trip to Alaska with his father in 1995 when he sat down at a
roadside restaurant near Anchorage and saw on his place mat a description of ice
worms. At first he thought it was a joke—nothing this whimsical could
possibly exist, he said to himself.
To understand the significance of Shain’s doubts, you must know that the man
has two main interests in life: worms and evolution. He’s been to the Amazon to
search for worms living in bizarre places under extreme conditions. His
experiences have left him well-versed in the mischievous pranks nature pulls on
biologists who think they’ve got everything figured out. In short, to make a
doubting Thomas out of Shain, the place mat worm had to sound truly,
fascinatingly, outrageously weird.
Weird, but undeniably real, it turns out. Ice worms resemble bits of black
thread less than 15 millimetres long—average-sized, as far as worms go.
They are found only in permanent snow fields on the mountains of Washington,
British Columbia and Alaska. Not to be confused with another kind of ice worm
which lives in deep sea vents, Shain’s ice worms are oligochaetes, segmented
worms belonging to an entirely different class from their more ancient
cousins.
Shain was determined to follow up his discovery in the diner. He soon learnt
the truth about ice worms from rangers working at Portage Glacier, one hour
south of Anchorage. The locals were so tickled by his interest that they
promised to mount an ice worm expedition and collect some live specimens for
him. A year later Shain’s first shipment arrived by courier. On ice,
naturally.
To study ice worms, Shain essentially had to start from scratch. First he
wanted to see how an ordinary worm, in this case a leech, which is the beast
normally under study in Shain’s lab, would fare in the ice worm facility. The
answer? Not well. The leeches’ membranes seize up and a key protein loses its
ability to form the polymers that keep the creatures’ cytoskeleton intact. “They
basically don’t move,” says Shain. “They are very lethargic for about two weeks.
Then they die.”
Ice worms, on the other hand, appear to be in heaven. When his colleagues
express disbelief, Shain puts his critters on a chunk of ice and makes them
watch as the worms burrow into the nearest fissure and disappear. Indeed, it is
only under normal circumstances that ice worms feel inadequate. In sunlight, for
instance, they simply melt away.
Recently, Shain has captured the first scanning electron microscope images of
ice worms, so he can get a better look at some of the morphological features
that may be adaptations to life in the cold. One is a peculiar head pore, larger
than the mouth and situated above it. Shain guesses that this might be used for
laying down a trail of mucous or chemicals to help the ice worm navigate through
a world devoid of landmarks. Or maybe the pore excretes salt, which helps the
worm melt tunnels through the ice.
Shain, who is hoping to publish a description of his micrographs early in the
new year, is clearly bowled over by the adult ice worm’s ability to survive at 0
°C or even colder. What interests him even more, however, is how an ice worm
embryo can develop at all under such conditions. Developmental biologists often
chill growing embryos to watch them in slow motion. With an ordinary worm,
development slows considerably at 10 °C. “At about five degrees,” says
Shain, “it stops.”
Somehow ice worms have found a way around this. Or have they? Another
possibility that excites Shain is that ice worms are perfectly happy to amble
along in slow motion—to redefine the concept of time. And why not? If your
environment is as dull as a blank TV screen, who cares what speed the rest of
the living world goes at?
If this scenario is correct, then ice worms may be pushing at the limits of
longevity’s tightly sealed envelop. For this reason, Shain would love to know
how long ice worms live, but is embarrassed to admit that his first colony died
after he allowed their bowl to dry up.
That brings up another problem: all embryos need liquid water, a vestige of
life’s ancestral beginnings. How have the ice worms managed to solve this one?
Shain doesn’t think they have. “I have a theory,” he says. “Ice worms have been
observed in puddles that form on the surface of glaciers during the summer. And
they have been found in large balls in these puddles.” Perhaps they are
copulating, he says, and later depositing their eggs in the meltwater.
The answer to this particular mystery may be close at hand. Three weeks ago a
new batch of ice worms arrived and the squigglers appear to have taken quite
well to their Tupperware environment. They’ve all clumped together in a tangled
mass, and Shain thinks it must be orgy time in the old icebox. “They must think
it’s summer,” he says.
Shain can’t say for sure if anything will come of understanding what makes
ice worms so unique. Unlike most other scientists, though, until recently he had
no peers to restrain his imagination. (That’s about to change. Shain is helping
a colleague in Arizona to set up another ice worm research facility.) He talks
about potential antifreeze proteins and enzymes that, if found, could be used in
industrial processes at low temperatures. But he also talks about ideas that are
more out there. Way out there. “If we’re ever going to travel through space into
other galaxies, our lifespan isn’t long enough,” he says. “By the time we get
there, we’d be dead. But if we understood the mechanisms the ice worms use, we
could super-cool ourselves…”
Before you start packing your bags for some distant nebula, there is one
small problem. To conduct molecular studies of ice worm membranes, to study
their genes, to figure out what enzymes and proteins make these critters tick,
all requires a steady supply of ice worms. Given the ice worms’ remote haunts,
getting that steady supply is Shain’s biggest headache. So if there’s someone
out there who knows the mountains and has a lot of leisure time on their
hands—a modern-day Prince Luigi, perhaps?—your services are
required.