Sphaerosyllis erinaceus Claparède, 1863

Synonyms:
Sphaerosyllis longicauda : Auctt., non Webster & Benedict, 1887
Sphaerosyllis latipalpis Levinsen,1883

Distinguishing characteristics
Body covered with numerous papillae, which are encrusted with mud and sand.
Antennae, tentacular and dorsal cirri well developed and flask-shaped.
One pair of tentacular cirri.
Dorsal cirri absent on the second parapodium.

Species description
Body quite short, broad, upper surface covered with numerous papillae encrusted with mud and sand. Prostomium 4 blackish eyes with lenses, in one line, and 2 eyespots. Palps semicircular as long as the prostomium, divided by a lateral groove only. Lateral antennae flask-shaped, about as long as the prostomium. Median antenna a little longer than lateral ones. Tentacular cirri and dorsal cirri flask-shaped. Dorsal cirrus absent on the second parapodium. Blades of compound chaetae moderate long and short, unidentate. All parapodia with one S-shaped upper unidentate simple chaeta. Pygidium with 2 flask-shaped anal cirri, slightly longer than dorsal cirri.

Size
Body up to 5 mm long for 22-37 segments.

Color
Transparent to yellowish-white.

Habitat
Amongst other evertebrates, holdfasts of brown algae and on various kinds of soft bottoms.

Mobility
Mobile.

Feeding
Carnivore.

Life cycle

Distribution
Probably cosmopolitan, English Channel, Skagerrak.