Based on material collected during the DIVA-Artabria I project (2002 cruise) from deep areas (629–1132m) of the shelf and upper slope off the Ártabro gulf (Galicia, NW Spain), two new species of Syllidae (Annelida: Polychaeta) are described. Eurysyllis mercuryi sp. nov. is characterized by having compound chaetae with elongated blades, provided with long spines, and Syllis mercedesae sp. nov. is diagnosed by the possession of a unique combination of straight aciculae, protruding from parapodial lobes in posterior-most chaetigers, and moderately long spiniger-like chaetae in midbody provided with indistinct subdistal tooth, appearing almost unidentate. Eurysyllis mercuryi sp. nov. is the fifth species of the genus described worldwide and the second reported species in European waters after E. tuberculata Ehlers, 1864.
Eastern Atlantic warm temperate to boreal
Lusitanian region: Azores, Madeira, Canary Islands to west Iberian Peninsula together