M. posthuma is a medium size endogeic geophagous earthworm (∼12 cm in length, and 5 mm diameter on average at the adult stage) which produces approximately 5–10-fold its own weight in casts per day ( Bottinelli et al., 2010, Jouquet et al., 2011 and Jouquet et al., 2012). Its casts range from 1 to 3 mm and are mainly found belowground.