Ice worm
Ice worms (also written as ice-worms or iceworms) are enchytraeid annelids of the genus Mesenchytraeus. The majority of the species in the genus are abundant in gravel beds or the banks of riverine habitats, but the best-known members of the genus are found in glacial ice. They include the only annelid worms known to spend their entire lives in glacial ice, and some of the few metazoans to complete their entire life cycle at conditions below . The genus contains 77 species, including the North American glacier ice worm ("Mesenchytraeus solifugus") and the Yosemite snow worm ("Mesenchytraeus  gelidus"). Ice worms eat snow algae and bacteria. They live at zero degrees Celsius (32 degrees Fahrenheit), but if temperatures dip even slightly below that, according to a Washington State University researcher, the worms die. Species. The genus contains 77 species. They are the following: "Mesenchytraeus franzi" is a junior synonym of "Cognettia clarae". "Mesenchytraeus megachaetae" Shen, Chen & Xie, 2011 has been renamed "Mesenchytraeus gigachaetus" Xie, 2012 due to the previous name being preoccupied by "Mesenchytraeus megachaetae" Bretscher, 1901, a junior synonym of "Mesenchytraeus armatus."