Phenotypic diversity, taxonomic remarks and updated distribution of the Mediterranean Jujubinus baudoni (Monterosato, 1891) (Gastropoda Trochidae)

Jujubinus baudoni (Monterosato, 1891) shows highly diverse chromatic and morphological patterns. Based on the examination of the type material and series of specimens from private collections, and of recent findings from Sardinia, we reviewed and updated the distribution of this species, and figured the three representative shell colour morphs which are constant in local populations. A comparative SEM analysis did not outline significant differences among shells with greatly different colour patterns, thus justifying their belonging to a single specific entity. The survey of the material of J. baudoni did not show a strict correspondence between Corse and Sardinian shell colour morphs and their geographical distribution, not allowing to clearly state trends and relationships among island populations. On the contrary the colour pattern of the continental shells of J. baudoni seems to be constant and different from the ones of the island shells, indicating a well separated colour morph. This study confirmed that the distribution of J. baudoni is limited to the north-western Mediterranean Sea, with its eastern range widened to the La Maddalena Archipelago (Sardinia). The record of this species from Azores is due to a misidentification with J. pseudogravinae Nordsieck, 1973, which is also figured for comparison. A lectotype and paralectotypes of Trochus baudoni are herein designated.