Molecular Detection for Two Abalone Shell-boring Species Polydora haswelli and P. hoplura (Polychaeta, Spionidae) from Korea using 18S rDNA and cox1 Markers

Polydora species (Polychaeta: Spionidae) are morphologically similar and have shell-boring abilities that are harmful to commercially important mollusks; genetic analysis is therefore important for their identification. Here, molecular evidence for Polydora species in Korean cultured abalone (Haliotis discus hannai) is first reported. DNA barcode markers (Nuclear 18S rDNA and mitochondrial cox1 regions) identified Polydora haswelli and P. hoplura in infested abalone shells. The cox1 marker was efficient in detecting Polydora species even in samples contaminated with shell debris. The findings provide useful information for the accurate identification of Polydora species and for monitoring harmful spionids in mollusk aquaculture farms.