Tuesday, January 11, 2011

Species spotlight V

Deroceras panormitanum (Lessona & Pollonera, 1882)
Żejtun, Malta

This is another slug described by the same folks who named yesterday's featured species. It is a south-west Mediterranean species which has since spread to most of Europe, North America and elsewhere. It can be distinguished from other Maltese slugs by its chestnut-pink colour, smaller size (about 2-3cm) and a fingerprint-like pattern on its back. A very similar species, Deroceras golcheri Regteren Altena, 1962 is endemic to Malta but is much rarer, and in places where it occurs with D. panormitanum, differences in colour and size are constant and consistent. D. golcheri also has a black mark near its pneumostome (respiratory opening, visible in both pictures) which D. panormitanum lacks.

Deroceras also has an internal shell.

Pictures are of the same individual.

  • small fast-moving slug
  • pinkish or pale brown
  • mucus transparent
  • fingerprint pattern on back
  • no black mark near respiratory opening

1 comment:

  1. You might be interested in the information on this species in a recent article:
    H. REISE, J.M.C.HUTCHINSON, S. SCHUNACK & B. SCHLITT 2011. Deroceras panormitanum and congeners from Malta and Sicily, with a redescription of the widespread pest slug as Deroceras invadens n. sp. Folia Malacologica 19:201–233.
    Downloadable via:

    It turns out that D. panormitanum is restricted to Malta and Sicily and distinct from the species that is now widespread elsewhere in Europe and on other continents. We also observe that the external character that you mention (the mark above the pneumostome) is not reliable at distinguishing D. golcheri from D. panormitanum: sorry, but you have to dissect them.


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