Ice Worm

Ice Worm

Ice worms are species of the genus Mesenchytraeus, and represent the only annelid worms known to spend their entire lives in glacial ice. They include Mesenchytraeus solifugus, M. harrimani, M. kuril, M. maculatus and M. obscurus.

The first ice worms species were discovered in 1887 in Alaska, on the Muir Glacier. These glacier ice worms can be found on glaciers in Alaska, Washington, Oregon and British Columbia. They have not been found in other glaciated regions of the world. The name "solifugus" is Latin for "sun-avoiding," as ice worms retreat underneath the ice before dawn. Enzymes in ice worms have very low optimal temperatures, and can be denatured at even a few degrees above 0 °C (32 °F). When ice worms are exposed to temperatures as high as 5 °C (41 °F), their membrane structures disassociate and fall apart (i.e., "melt") causing the worm itself to "liquify." Ice worms are several centimeters long, and can be black, blue, or white in color. The ice worms come to the surface of the glaciers in the evening and morning. On Suiattle Glacier in the North Cascades population counts indicated over 7 billion ice worms on that glacier alone.

It is not known how ice worms tunnel through the ice. Some scientists believe they travel through microscopic fissures in ice sheets, while others believe they secrete some chemical which can melt ice by lowering its freezing point, like an antifreeze. They feed on snow algae.