Pileolaria berkeleyana, a spirorbin polychaete worm introduced to the Netherlands (Polychaeta: Serpulidae: Spirorbinae)

The spirorbin polychaete worm Pileolaria berkeleyana, new for the fauna of the Netherlands, was found at different localities in the Oosterschelde area in the province of Zeeland. They were found on empty shells and on boulders, which confirms their preference for hard substrates. The introduction of the species is discussed, together with the three other species of Spirorbinae recorded as living on the coast of the Netherlands.