The Use of Anhydrobiosis by Soil Nematodes in the Antarctic Dry Valleys

1. Anhydrobiosis is a survival strategy used by soil nematodes that confers protection from environmental stress and is induced by desiccation. 2. To study the use of anhydrobiosis by soil nematodes from the Antarctic Dry Valleys, soil was collected from field sites, and nematodes were extracted using an anhydrobiotic extraction technique. Nematodes were found in a coiled form that characterizes the anhydrobiotic state. 3. The proportion of nematodes coiled ranged from 30 to 80% and appeared to reach a maximum in soils drier than 2% gravimetric soil moisture content. 4. Wetting of dry soils to 12% gravimetric soil moisture content resulted in rapid uncoiling of nearly 100% of nematodes within 6 h. 5. In this cold desert ecosystem, long periods of inactivity appear to be an important aspect of soil nematode life history as their activity may be restricted to the period following infrequent snowfall and melt.