Ampharete finmarchica (M. Sars, 1864)

Synonyms:
Ampharete lindstroemi Malmgren, 1867 sensu Hessle, 1917
Amphicteis finmarchica Sars, 1865
Ampharete arctica Malmgren, 1866

Distinguishing characteristics
Thorax with 14 noto- and 12 pairs of neuropodia.
Long and stout paleae.
Branchiae in two groups very close to each other at middorsum; first three of each group in a transverse row, the fourth just behind the middle one of the three.

Species description
Body cylindrical, tapering posteriorly. Prostomium with three lobes, usually with two eyespots. Branchiae in two groups very close to each other at middorsum. First three branchiae of each group in a transverse row, the fourth just behind the middle one of the three. Paleae with pointed tips, 12-16 on each side. 14 thoracic segments with notopodia with capillary chaetae, posterior 12 also with neuropodia with uncini. 13 or exceptionally 14 abdominal uncinigerous segments with small, rudimentary notopodia. Pygidium with two long cirri and a number of small, round papillae. Tube – thick and loose, straight cylindrical, built of mud and sand lined with a thin secretion.

Size
Worm up to 50 mm long.

Color
In alcohol pale yellow.

Habitat
Lives mainly on silt, muddy and mixed bottoms, which can contain some sand grains, rarely in pure sand. From the upper sublittoral to depths exceeding 5000 m. Species very sensitive to organic enrichment and present under unpolluted conditions.

Mobility
Sedentary.

Feeding
Surface deposit feeder.
Detritus feeder.

Life cycle
Larvae – not pelagic.

Distribution
North Atlantic, West Greenland, Quebec, Canadian Arctic, Siberian Arctic, Bering Sea, North American Pacific, Sea of Okhotsk, Japan Sea. East Greenland, Svalbard, Jan Mayen, entire Norwegian coast, Barents Sea, North Sea, Skagerrak, Swedish west coast, Öresund.