Pseudopolydora (Annelida: Spionidae) from European and adjacent waters with a key to identification and description of a new species

Four Pseudopolydora Czerniavsky, 1881 species from European and adjacent waters are distinguished and a key to their identification is provided. Pseudopolydora antennata (Claparède, 1868) is redescribed based on material from the type locality, Gulf of Naples, Italy. Pseudopolydora pulchra (Carazzi, 1893) (type locality in the Gulf of Naples) is also redescribed based on material from Italy. Most previous records of the Asian P. paucibranchiata (Okuda, 1937) from North European waters are herein referred to a new species, P. nordica sp. nov. The latter differs from P. paucibranchiata by the absence of an occipital antenna on the prostomium and yellow ramified chromatophores on palps. Native to the Northwest Pacific, P. paucibranchiata was first recorded in European waters from the Tyrrhenian Sea, Lazio, Italy, in 1978. Since then, the species has spread widely in the Mediterranean and in 2015 was first recorded from northern Europe in the Netherlands.