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.
Norwegian Sea, 64016.9’N 0011.7’W, 2630 m.
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.
Deep parts of Norwegian Sea; 900–3000 m.
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.