Shell-boring polychaete worms can severely impact shellfish aquaculture by reducing growth rates and compromising tissue quality of their molluscan hosts. In this study we report the first known instance of shell-infestation of commercially important scallops on Nantucket Island by the cryptogenic polydorid Polydora neocaeca. Additional analyses indicate a high level of genetic connectivity between worms from Nantucket Island and the US mainland, forming a distinct haploclade which is genetically isolated from populations from South Africa and Japan. While transportation of infected seed could have introduced the worm to Nantucket, limited sampling and the paucity of sequence data available makes it impossible to definitely determine its origins.
Keywords: Biosecurity; Mud-blister worm; PCR; Phylogenetics; Polydorid.