Alison Woods and Julia Carey found this empty shell of Helix pomatia, the Roman Snail or Edible Snail, at Grangelands, Buckinghamshire on or shortly before 18th February 2009. Julia is well acquainted with this population of the snail and has never seen one, before or since, with neat circular holes in the shell, despite looking at lots of shells. What made those holes? I’ve been puzzling over the specimen for the best part of a year without coming any closer to an answer. Can you help?
There are 6 circular holes in the shell, each of 4 mm diameter. I’m guessing they were made by a predator but why not attack the exposed body of the snail at the mouth of the shell rather than breaking through the shell wall?
The damage to the Helix shell is reminiscent of that caused to bivalves by the marine necklace shells so my best guess is that this Helix was attacked by another mollusc, perhaps the Leopard Slug Limax maximus which is known to be a predator of other slugs at least.
Any and all suggestions gratefully received!