The marine Heterobranchia (Mollusca: Gastropoda) fauna of the Aeolian archipelago (Tyrrhenian Sea). First contribution: Lipari and Vulcano

It is here presented the first faunistic list of the marine Heterobranchia fauna of Lipari and Vulcano, the two southernmost islands of the Aeolian archipelago. Through the examination of ten dive sites (six in Lipari and four in Vulcano), it was found a total of 30 marine Heterobranchia species (1 Rhodopoidea, 1 Pleurobranchida, 21 Nudibranchia, 1 Cephalaspidea, 1 Umbraculida and 5 Sacoglossa). Specifically, in Lipari 26 species were found, while in Vulcano 18 taxa. This numerical difference between the two islands might be related to the higher presence of different environments and habitats in Lipari compared to Vulcano