An updated overview of the marine alien and cryptogenic species from the Egadi Islands Marine Protected Area (Italy)

An updated overview of the marine alien and cryptogenic species recorded in the Egadi Islands Marine Protected Area (Tyrrhenian Sea, Italy), based on relevant publications, grey literature and unpublished data, is presented and discussed. Altogether, 17 species (14 aliens and 3 cryptogenic) belonging to five taxa are present in the area: Rhodophyta (Antithamnionella elegans, Asparagopsis armata, Asparagopsis taxiformis, Bonnemaisonia hamifera, Botryocladia madagascariensis, Ceramium strobiliforme, Laurencia caduciramulosa, Lophocladia lallemandii, Neosiphonia harveyi, Womersleyella setacea), Chlorophyta (Caulerpa cylindracea and Caulerpa taxifolia), Mollusca (Aplysia dactylomela), Arthropoda (Percnon gibbesi) and Cordata (Fistularia commersonii, Kyphosus vaigiensis and Stephanolepis diaspros). The overall Mediterranean presence of one further taxon recorded from the area, Zygochlamys patagonica (Mollusca), is here confuted since recent findings of living specimens with certain data are missing. One loose valve of "Pinctada imbricata radiata (Mollusca)" was found in 2010 at Favignana, but we did not include it in the list of alien species, pending further finding of living or dead specimens. Unpublished distributional data are reported for some of these species, and their known distribution in the Aegadian Archipelago is mapped. Records of P. gibbesi (a conspicuous number of specimens) constitute the first for the archipelago. All the species included in the present paper were recorded after the Egadi Islands Marine Protected Area was established, with the first record dating back to 2000. This is presumably due to the recent increase in research programs on marine reserves. Finally, we provide the establishment status of all the recorded species updated to 2015, and discuss why unaided spread (whether alien or native) and/or transport-stowaway constitute the more plausible vectors of introduction.