Infected Slugs: Case #9

This case is unique in that the slug does not have an external growth (yet), but an obvious internal one. To all appearances it looks as if the slug has swallowed a marble that's become lodged near its tail! However, its mantle is not noticeably warped and still covers its neck, and the slug otherwise looks fairly healthy, so I'd guess that the parasites have not completely taken over. But soon the internal growth should manifest itself externally. (I apologize for the poor quality of some of these photos. These winter nights are playing havoc with my shutter speed.)

I believe this is the same slug as in the photos above. The washed-out appearance of these photos makes a certain ID difficult. Anyway, I know it crawled down off the porch after the first shoot...