Description: Prostomium with two long (100-200 µm) antennae, distally slightly swollen. Two laterally inserted club-shaped palps (30-40 µm long), arising laterally. Eight chaetigers, posteriormost ones widest. Parapodia with relatively short ovoid cirri (maximum length 20 µm), lacking in buccal segment and last segments; a ventral and dorsal bundle of 5-10 finely serrated capillary chaetae. Two elongate pygidial cirri, tapering in the distal third (75-100 µm long). 4 buccal pieces (N. gracile-detail).
Size: Length 300-500 µm.
Habitat: Coarse, sandy and shelly, sublittoral sediments. Occasionally in lower parts of tidal sandy beaches.
Distribution: North east Atlantic, North Sea (Helgoland), English Channel, Northern Norway.
Kingdom Animalia Phylum Annelida Class Polychaeta Family Nerillidae Genus Nerillidium Species Nerillidium gracile
