Polydora quadrilobata

Jacobi, 1883

Description:
Body relatively broad and flat anteriorly, cylindrical posteriorly.
Prostomium anteriorly more or less incised, with or without four or six eyes, without median antenna, posteriorly with a caruncle reaching chaetiger 2-3. Two long palps present.
First notopodium with chaetae.
Notopodial postchaetal lobes short and broad. Neuropodial postchaetal lobes smaller, oval.
Fifth chaetiger dorsally with a few bent, broadly winged capillary chaetae and 5-7 modified chaetae in a row; ventrally capillary chaetae. Modified chaetae thick , with a cleft tip and a brush-like tuft.
7th and following neuropodia with 3-5 bent hooded hooks with a small distal tooth and a bigger subdistal tooth. Neuropodial capillaries also present nearly to the body end. Posterior notopodia with needle-like chaetae that are as thick, but shorter than the capillaries of the anterior segments (P. quadrilobata-detail).
The cirriform gills overlap each other on the dorsal mid-line. Gills from chaetiger 7 or 8 to about chaetiger 35-55.
Pygidium with four broadly rounded lobes.

Size:
Up to 25 mm for 90 segments.

Colour:
Living animal reddish brown, with brown pigment in anterior part.

Habitat:
Occupies a tube of sand and mud-particles; embedded in mucus. In mud or sand, from lower eulittoral to 210 m.

Distribution:
North Sea, Kattegat, Isefjord, Ă–resund, Bay of Kiel, North Atlantic to Mediterranean, North Pacific, Arctic.

%LABEL% (%SOURCE%)