A new species of the Marphysa sanguinea complex (Annelida: Eunicidae) from Fujian, China

Marphysa fujianensis sp. nov., a new species collected from coastal waters of Fujian Province, China, was described based on both morphological and molecular analyses. The new species belongs to Group B of the Marphysa sanguinea complex, and it is characterized by having a deeply bilobed prostomium, bearing three types of pectinate chaetae (i.e., IS1, AN1, and AN2), 12 neuroaciculae, and only unidentate subacicular hooks. The partial COI gene sequences of the new species exhibit 4.00%28.14% divergence from those of other sequenced Marphysa species in public databases. An updated key to Group B Marphysa species from East Asian waters is provided.