Revision of Gibberula philippii (Monterosato, 1878) in a populational approach (Gastropoda Cystiscidae)

The species Gibberula philippii (Monterosato, 1878) (Gastropoda Cystiscidae) is revised and one lectotype and six paralectotypes are appointed from a lot of Palermo belonging to the Monterosato Collection in the Civic Museum of Roma. Palermo is defined as the type locality of the species. The phenetic variability of G. philippii (shell morphology and animal chromatism) is displayed and commented through numerous specimens from various localities of the Mediterranean Sea and a sample from the Ibero-Moroccan Gulf (Casablanca). Gibberula cristinae with this populational approach is synonymous with G. philippii. In the present state, no sibling species is detected within the Mediterranean G. philippii group of forms and G. philippii is considered as a polymorphic species. The alleged complex of sibling species of G. philippii described recently from the Canarian Archipelago is discussed as a comparative case. The populational approach and the extensive study of the phenetic variability is argued to offer high benefits by itself in malacology studies and to contribute highly to the efficiency of integrative taxonomy.