Paragnath variation was examined in two populations of the epitokous form of the polychaete Perinereis cultrifera from the English Channel and the Algerian Mediterranean coast. Populations differ from each other in the mean number of paragnaths in groups

An Asian species of Perinereis, which has been regarded as a local population of a cosmopolitan species P. cultrifera (Grube, 1840) (type locality: Italy), is described as a new species, P. euiini., based on Korean specimens. This new species is distinguishable

Despite being one of the most common groups of polychaetes on intertidal shores, the genus Perinereis (Nereididae) is comparatively poorly known taxonomically, with confusion still existing due to the lack of comprehensive systematic studies. The systematics