Sosane bathyalis is a very small species, only up to 3 mm long. It can be found in deep parts of the Norwegian Sea at depths between 900 and 3000 meters.

Type locality

Norwegian Sea, 64016.9’N 0011.7’W, 2630 m.

Key characters

Measurements: Up to 3 mm long.

Number of thoracic chaetigers, excluding paleae: 12

Number of thoracic uncinigers: 9

Number of abdominal uncinigers: 12

Prostomium: Trilobed; eyespots absent.

Mouth tentacles: Smooth.

Branchiae: Three pairs of branchiae in two widely separated groups; branchiae arranged in triangles.

Paleae: Small with filiform tips.

Special features: 12th pair of thoracic notopodia elevated and laterally enlarged; notochaetae usually crossing mid-dorsally.

Pygidium: With long lateral cirri.

Tube: Unknown.

Distribution

Deep parts of Norwegian Sea; 900–3000 m.

Similar species

Sosane bathyalis and Sosane wahrbergi are morphological very similar, particular since fixed specimens of S. wahrbergi quite often miss eyes. Sosane bathyalis are generally smaller than S. wahrbergi and occur much deeper.

Sources

Holthe T (1986b). Polychaeta Terebellomorpha from the northern Norwegian Sea and the Polar Sea, with descriptions of Mugga bathyalis sp.n. and Ymerana pteropoda gen. and sp.n. Sarsia 71: 227-234.

Jirkov IA (2001). [Polychaeta of the Arctic Ocean] (In Russian). Polikhety severnogo Ledovitogo Okeana. Yanus-K Press. Moscow, 632 pp.

Personal observations, Alvestad T.