Monitoring marine biodiversity in Sicily: new NIS records and neglected species

Sicily, the largest island in the Mediterranean Sea, holds a strategic position for the routes of dispersal of marine species entering the basin from the Atlantic Ocean and the Red Sea. Through case studies relating to activities carried out under the NBFC framework, this contribution aims to strengthen this assertion. The fouling communities living on nautical ropes were investigated between 2023 and 2025 in three harbours (Trapani, Palermo, and Licata). New occurrences of NIS or cryptogenic isopods (Paranthura japonica, Mesanthura cf. romulea, Paracerceis sculpta), amphipods (Caprella scaura, Jassa slatteryi, Laticorophium baconi, Stenothoe georgiana), pycnogonids (Anoplodactylus californicus), bivalves (Isognomon sp., Brachidontes pharaonis), and tunicates (Microcosmus squamiger, Styela plicata, Distaplia bermudensis) were detected in Trapani, while the isopod Mesanthura cf. romulea and the amphipod Laticorophium baconi were reported for the first time in Licata. The latter species and the pycnogonid Achelia sawayai were also newly recorded in Palermo. Contextually, rare or neglected species were also collected. These include two copepod species parasitic of ascidians (a yet unidentified botryllophilid in Polyclinum aurantium and Bonnierilla similis in Styela plicata) and the marine mite Litarachna duboscqi, whose record accounted for the first sighting in the central Mediterranean. These observations overall demonstrate that the local biodiversity is still not yet sufficiently explored and highlight the necessity of continuous monitoring activities to understand the dynamics of biological invasions and increase the knowledge on rare or neglected taxa.