Glyphanostomum pallescens can be up to 35 mm long. It has a characteristic annulated tube. It can be found in the Norwegian Sea, Barents Sea, around Svalbard and northern Norwegian coast south to Møre at depths between 100 and close to 3000 meters.

Type locality

Kara Sea, 75o40’N 78o40’E, 45 m.

Key characters

Measurements: Up to 35 mm long.

Number of thoracic chaetigers: 14

Number of thoracic uncinigers: 11

Number of abdominal uncinigers: About 30.

Prostomium: Without ridges or lobes; with one visible pair of depressions (nuchal organs).

Mouth tentacles: Smooth.

Branchiae: Three pairs of branchia in two widely separated groups; branchiae in each group in transverse row.

Paleae: Absent.

Special features: Thoracic segments gradually increasing in length posteriorly; notopodia gradually shifting to a more dorsal position.

Pygidium: With two long lateral cirri and several small papillae.

Tube: Long, thin, and distinctly annulated; thin layer of organic secretion with layer of mud often with sponge spicules attached.

Distribution

Norwegian Sea, Barents Sea, Svalbard, northern Norwegian coast south to Møre; from deep (close to 3000 m) in Norwegian Sea to shallow (about 100 m) in Svalbard and Northern Norway.

Similar species

The annulated tube, in combination with the prostomium without ridges or lobes and three pairs of branchiae in two widely separated groups, makes it unlikely to confuse adult complete specimens of Glyphanostomum pallescens with any other Ampharetidae in Norwegian waters. 

Sources

Holthe T (1986a). Polychaeta Terebellomorpha. Marine Invertebrates of Scandinavia 7: 1-192.

Théel HJ (1879). Les Annélides Polychètes des mers de la Nouvelle-Zemble. Kungliga Svenska Vetenskapsakademiens Handlingar 16(3): 1-75, plates I-IV. https://www.biodiversitylibrary.org/page/33811612

Personal observations, Alvestad T.