Aricidea (Allia) suecica Eliason, 1920

Synonyms:
Aricidea jeffreysii (non McIntosh) Hartmann-Schröder, 1971

Distinguishing characteristics
Prostomium with median, club-shaped antenna reaching chaetiger 2 or 3.
Large branchiae, starting at chaetiger 4.
Modified chaetae with a thin terminal prolongation.

Species description
Body long, thin and cylindrical. Prostomium roundly triangular or heart-shaped with two small eyes and a median, club-shaped antenna reaching chaetiger 2 or 3. Up to 30 pairs of large branchiae, starting at chaetiger 4. Notopodial postchaetal lobes in the first chaetiger small and conical, becoming bigger until the 4th chaetiger; behind the branchiae thin and filamentous. All parapodia with capillary chaetae. Neuropodia of postbranchial segments bear also up to 10 modified chaetae distally hooked with a thin terminal prolongation. Pygidium with 2 long and 1 short cirrus.

Size
Up to 20 mm for 120 segments.

Color
Alive: with yellowish or brownish back and dark pigmentation on prostomium and anterior segments or colourless.

Habitat
Sublittoral to 2500 m. Muddy bottoms.

Mobility
Mobile.

Feeding
Surface deposit feeder. Herbivore.
Facultative suspension feeder.

Life cycle

Distribution
Arctic, North Pacific, North Sea, Öresund and Baltic Sea.