Samytha sexcirrata can be up to 25 mm long. It can be found along the entire Norwegian coast at depths between 100 and 500 meters.
Innhold
Type locality
Manger, Norway, 90–110 m.
Key characters
Measurements: Up to 25 mm long.
Number of thoracic chaetigers: 17
Number of thoracic uncinigers: 14
Number of abdominal uncinigers: 13
Prostomium: Trilobed; eyespots absent.
Mouth tentacles: Smooth.
Branchiae: Three pairs of branchiae in two groups separated by distance equal to about one branchial base diameter; branchiae in transverse row.
Paleae: Absent.
Special features: Lower lip enlarged.
Pygidium: Without lateral cirri, with numerous papillae.
Tube: Made of sand.
Fig. 1. Anterior end. br: branchiae (branchial scars), lwl: lower lip, pr: prostomium
Fig. 2. Abdominal neuropodium with uncini
Distribution
Entire Norwegian coast; 104–460 m (Jirkov 2001).
Remarks
Holthe (1986a) reports S. sexcirrata down to 5000 m. This depth is questionable, at least in Norwegian waters.
Similar species
The large lower lip, in combination with three pairs of branchiae and absence of paleae, makes it unlikely to confuse adult complete specimens of Samytha sexcirrata with any other Ampharetidae in Norwegian waters.
Sources
Holthe T (1986a). Polychaeta Terebellomorpha. Marine Invertebrates of Scandinavia 7: 1-192.
Jirkov IA (2001). [Polychaeta of the Arctic Ocean] (In Russian). Polikhety severnogo Ledovitogo Okeana. Yanus-K Press. Moscow, 632 pp.
Sars M (1856). Nye Annelider. Fauna littoralis Norvegiae (Fredrik D. Beyer. Bergen). heft 2:1-24., available online at http://biodiversitylibrary.org/page/41477013
Personal observations, Alvestad T.