Doorboorde Grote tepelhoorns Euspira catena (da Costa 1778)

Regularly, empty shells of Euspira catena found stranded on Dutch beaches show irregular holes. These start as boring holes of the polychaete Polydora ciliata which bore their U-shaped holes parallel to the shell surface. The holes become larger due to erosion of the empty shell during transport, rolling over the sandy sea bottom. As Euspira lives largely infaunal, with its shell often entirely covered by their foot and propodium, Polydora will be unable to bore in living Euspira. However, empty Euspira shells on the sea bottom will be rapidly used by hermit crabs. As these live epifaunal, encrusters and boring organisms get an opportunity to use the shell as well. The Euspira shells with holes are ‘pagurized’ shells sensu Walker (1988), a nice example of re-use and recycling in nature.