Oersted, 1843
Description:
Body slender with long tapering posterior half. Prostomium pentagonal, eyes rather small. Proximal part of proboscis with 12 longitudinal rows of papillae, 6 on each side, the median rows of which have about 13-16 papillae. In larger specimens these become leaf-like. Distal half with six longitudinal rows of large tubercles and a terminal ring of about seventeen papillae. Segment 1 not visible dorsally. Tentacular cirri of segment 1 reaching about segment 7. Dorsal and ventral tentacular cirri of segment 2 reaching about segment 12-13 and segment 6 respectively. Dorsal tentacular cirri of segment 3 as long as those of segment 2. Chaetae present from segment 3. Dorsal cirri of median segments rectangular in outline. Parapodial lobes asymmetrical, upper part slightly larger than lower. Ventral cirri with distinct ventrally directed tips (but not so in smaller specimens less than about 10 mm long). Pygidial cirri cylindrical, about seven times as long as broad (P. groenlandica-detail).
Size:
Length for a certain number of segments very variable, depending on degree of constriction in preserved animals. Largest specimen observed measured about half a metre in living state. Largest number of segments reported 700.
Colour:
Living animals with dark pigmentation anterior to eyes and on posterior lobes. Papillae of proboscis often with dark tips. Dorsum of a brownish-green metallic hue, with dark transverse bands centred in pseudosegmented areas. Dorsal cirri with dark spots. Eyes dark brownish red. It should be noted that the pigmentation of this species is very variable, some specimens almost lack pigment while others are very dark. Smaller specimens lighter. Pigmentation preserves well.
Habitat:
On sandy mud or mud. Intertidal to at least several hundred metres.
Distribution:
Circum-arctic; northern parts of the North Atlantic. English Channel, North Sea, Skagerrak, Kattegat, Öresund to the Bay of Kiel.