Intraspecific Variation in Calcium and Strontium Accumulation / Depuration in an Epigeic Earthworm Species

The accumulation and depuration of Ca and Sr were measured in populations of the earthworm Lumbricus rubellus, originating from calcareous and acidic soils, following laboratory exposure to a Sr-rich soil and a control soil. Populations from acidic soils accumulated more Sr than those from calcareous soils, when placed in a Sr-rich soil. After transferal from a Sr-rich soil to Sr-free soil, all populations depurated the majority of their body Sr (84 %-96 %) whilst maintaining their body Ca concentration; the Sr excretion was greater in the populations originating from acidic soils. ICP-MS cation analysis demonstrated the majority of Ca and Sr to be located in anterior alimentary canal and the majority of Sr was lost from this region.