Massive presence of the invasivePolydora websteri(Polychaeta: Spionidae) in the North Adriatic Sea (Mediterranean Sea)

Abstract

AbstractIn recent decades, the Mediterranean Sea has experienced a marked escalation in the introduction of non-native and invasive marine species.The global expansion of aquaculture, coupled with the increased movement of commercial species, has raised concerns about the potential for introducing parasites into new environments, posing a growing threat to marine ecosystems.Polydora websteriis a shell boring polydorin worm that induces the formation of mud-filled blisters within the shells of molluscs. The annelid is considered indigenous to the Asian coasts and has been documented in various locations across the globe. In the present work, we report a massive presence ofP. websteriin several sites of the North Adriatic costline and we provide some diagnostic features that are useful to identify the species.Polydora websterican be distinguished of a lateral flange on chaetiger 5. Moreover the palps are characterized by continuous black lines along the margins of the ciliated groove.The combined findings of this study provide compelling evidence thatP. websteriis expanding its range within the Mediterranean coast. Given the potential for severe ecological and economic impacts associated with this invasive polychaete, this study serves as an urgent call to action for increased monitoring ofP. websteriin both farmed and wild Pacific oysters in the Mediterranean Sea. Identification key of MediterraneanPolydorais provided.