Cold tolerance in Tardigrada from Dronning Maud Land, Antarctica
Survival at low temperatures was studied in three species of Tardigrada from Müihlig-Hofmannfjella, Dronning Maud Land, Antarctica. Both hydrated and dehydrated specimens of Echiniscus jenningsi, Macrobiotus furciger and Diphascon chilenense had high survival rates following exposure to -22°C for ca. 600 days, and dehydrated specimens following 3040 days at this temperature. In hydrated E. jenningsi, mortality increased with the duration of exposure from 7 to 150 days at -80°C, while mortalities of the two other species did not change. Hydrated specimens of all species were rapidly killed at -180°C, but all species exhibited good survivorship in the dehydrated state after 14 days at -180°C. In conclusion, hydrated tardigrades are able to survive extended periods at low temperatures, and dehydrated specimens are even better adapted to survive overwintering on Antarctic nunataks.
Unable to display preview. Download preview PDF.