Three new species of the genus (Annelida, Nereididae) from Egyptian coasts.

Despite being one of the most common groups of polychaetes on intertidal shores, the genus (Nereididae) is comparatively poorly known taxonomically, with confusion still existing due to the lack of comprehensive systematic studies. The systematics of species from the intertidal Egyptian coasts of the Red Sea, Gulf of Suez and Suez Canal have been investigated using morphology and the mitochondrial barcoding marker cytochrome oxidase subunit I (COI). New sequence data was obtained for 102 specimens and analysis included all publicly available COI data from other species. The COI data indicate that monophyly of the species group is doubtful, as specimens identified in this species group from south-eastern Asia and Australia form a monophyletic group exclusive of the three new species described in this study from the Red Sea region. A morphometric character set (26 characters) was used to identify and characterize each specimen in the study. Three distinct morphospecies belonging to the species group were found, each differentiated by the number and type of paragnaths on pharyngeal areas V and VI, relative sizes of parapodial lobes, type of notochaetae and neurochaetae, and form of the neurochaetal falciger blades. The three morphospecies were well supported by COI data: two of the three new species, and , are closely similar to sensu stricto, while the other, , is similar to . The new species are described and illustrated, and bring the number of species in to 97. The new species are compared and contrasted to the closely similar , and other congeners from the region.