Polydorid species (Annelida: Spionidae) associated with commercially important oyster shells and their shell infestation along the coast of Normandy, in the English Channel, France

Abstract Polydorid species (Annelida, Spionidae), which inhabit the shells of commercially important oyster Crassostrea gigas , were investigated along coast Normandy, France. Eight species, including five new records for Normandy ( Polydora onagawaensis websteri Boccardia pseudonatrix proboscidea and Boccardiella hamata ) two first in European waters P. B. ), identified based on morphological, molecular biological, ecological characteristics. belongs to ciliata / complex, was discovered wild suspended cultured oysters, as well limestone substrates. In phylogenetic analysis mitochondrial COI gene sequences, specimens P . collected from grouped together with USA into a single clade distinguished other three lineages that comprised Japanese specimens. inhabited oysters. hoplura Dipolydora giardi sp. observed sandy culture grounds. has been found muddy both Adult juvenile coralline algae, Mud tubes protrude outer surface shells, abnormal black calcareous deposits secreted inner against polydorid penetration.