The glacier worm, the mystery that NASA is trying to unravel

Hundreds of thousands of tiny black worms emerge from a vast expanse of white snow, a fact that is recorded at Paradise Glacier on Mount Rainier in Washington. The phenomenon is fascinating, but not new: These animals were first discovered in 1887 on the Muir Glacier in Alaska. Since then, they have been observed on most coastal glaciers in British Columbia, Washington State, and Oregon.

His discovery was fascinating because, for a long time, high altitude glaciers were viewed by biologists as arid places where life was essentially impossible.

The laws of biology dictate that when temperatures drop, bodily reactions slow down and energy levels drop. While warm-blooded animals must burn energy to maintain a relatively constant temperature, cold-blooded creatures become sluggish and even remain inactive when it is too cold. But not the ice worms.

An investigation by a team led by Michael J. Napolitano of the Department of Biology at the State University of New Jersey, published in Science, revealed that the ice worm, mesenchytraeus solifugus, is one of the few metazoan species to survive exclusively on glacial ice / snow.

In this study, they showed that the levels of adenylate (an enzyme that overactivates cell membranes) in the ice worm are maintained at levels much higher than those of other relatives of the species, and that its response to temperature change. is clearly the opposite, that is, ice worms increase energy levels when temperatures drop. Initially, this response is characterized by a sharp increase in the energy load of adenylate (even at temperatures below zero). These results suggest that ice worms developed a compensatory mechanism by which, at least in part, they can combat lethargy and inherent death in general. associated with cold temperatures.

“I think they’re like the mascot of the mountain glaciers in the west. Washington State University researcher Scott Hotaling said during an analysis. There are hundreds of them per square meter. You cannot walk without stepping on it ”.

An earthworm on the ice

Ice worms, aesthetically very similar to earthworms, are usually ink-black in color and are just over two centimeters in length. These animals, distant cousins ​​of earthworms, instead of earth, feed by eating snow algae, bacteria and anything found in snow.

They can spend their entire lives in snow and ice, but ice worms cannot survive freezing temperatures: Hotaling has conducted thermal tests and says ice worms can comfortably survive for at least a day or two at temperatures as low as the freezing point. 24 degrees, while dying when temperatures drop below zero.

These animals usually emerge in the afternoon and at dusk; Not much is known about them, but according to Hotaling, they are extremely tolerant of UV rays and believe they surface to get heat energy from the sun and find food. Another problem being investigated is that as glaciers disappear, so do ice worms. “We want to know everything about them before they go missing,” says Shirley Lang, a biologist at Haverford College in Pennsylvania. And I have no doubt that one day they will disappear if the glaciers continue to melt at the current rate. “

NASA finds this very interesting: the space agency awarded Dr. Dan Shain, an evolutionary biologist at Rutgers University who studies the survival of the ice worm under extreme conditions, more than $ 200,000 for his research.. Their findings could offer clues to how life can exist in extreme environments, perhaps to unravel mysteries about possible life forms on other planets or on cold moons.

The animals only live in coastal glaciers and are not found anywhere else in the world, although another similar species has been found in Tibet. We hardly know anything about it. While ice worms thrive at 32 degrees Fahrenheit, they cannot tolerate much lower temperatures in this frigid place.

In addition to their incredible energy, ice worms are also part of an ecosystem that we know very little about. They coexist alongside rotifers, tardigrades, algae, fungi and other microscopic creatures, says Scott Hotaling, a biologist at Washington State University. They also provide food for the birds.

Hotaling and his colleagues have observed at least five species of birds that eat ice worms. Invertebrates are a vital food source in places like Mount Rainier, where finches catch them in large numbers and feed them to their young, Hotaling says.

Birds can also help explain how these little animals can disperse from glacier to glacier. Animals are genetically different in disparate places, and animals in Alaska likely include a different species than most worms in the Pacific Northwest, Shain says.

Hotaling’s work suggests that live worms might be transported by clinging to the plumage or legs of birds, or perhaps some survive passage through the intestines of birds. A population of ice worms on Vancouver Island, for example, shows a close relationship with a population in southern Alaska, suggesting that one or more may have been carried there by a bird in the past. recent.

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