Aphelochaeta marioni (de Saint Joseph, 1894)

Synonyms:
Heterocirrus marioni Saint-Joseph, 1894
Tharyx marioni Fauvel, 1927

Distinguishing characteristics
Pair of thick palps and 1 filamentous branchia dorsally on all notopodia.
All chaetae capillaries, pygidium roundly triangular.

Species description
Body long, thin, filamentous. Prostomium conical, without eyes. Peristomium achaetous, partially divided into 3 annuli. Pair of thick palps on the anterior margin of the first chaetiger. One filamentous branchia dorsally on all notopodia from first chaetiger to nearly posterior end. Numerous capillary chaetae, the dorsal ones longer than the ventral ones. Pygidium roundly triangular. Anus dorsal, surrounded by 5 small papillae.

Size
Up to 100 mm for 200 segments.

Color
Reddish-brown.

Habitat
In mud; sometimes in sandy mud and between shells and stones.

Mobility
Sedentary.

Feeding
Surface deposit feeder.
Facultative suspension feeder.

Life cycle
Non-pelagic larvae.

Distribution
Atlantic up to Mediterranean, English Channel, whole North Sea, Skagerrak, Indian Ocean, Australia, Chile, Antarctic.