Ecology and Phylogeography of the ice worm Mesenchytraeus solifugus

Rachael Mallon, University of Puget Sound


The population genetic structure of glacially-obligate organisms can provide insight to historical glacial periods that geology alone can’t provide. Previous population structure studies of the glacially obligate ice worm, Mesenchytraeus solifugus on Cascade volcanoes suggest more extensive glacial and interglacial periods than previously thought. I further documented the phylogeography of Central Oregon ice worm populations by sampling worms on additional glaciers and addressed ecological questions by describing the relationship between ice worm surfacing times and densities to abiotic factors. I also performed elemental and stable isotope analysis of ice worms in order to derive an estimate of the lipid content of ice worms. Ice worm DNA sequences will allow us to infer the genetic structure of populations and relative times of divergence of populations. Central Oregon ice worm populations of great significance because they are in danger of extinction; their habitats have been decreasing steadily during the past century due to glacial ablation.