Lysippe fragilis can be up to 20 mm long. It can be found along the entire Norwegian coast at depths between 20 and 180 meters.

Type locality

Osterfjorden and Hjeltefjorden, Hordaland, Norway, 20–110 m.

Key characters

Measurements: Up to 20 mm long.

Number of thoracic chaetigers, excluding paleae: 17

Number of thoracic uncinigers: 14

Number of abdominal uncinigers: 8

Prostomium: Trilobed; numerous eyespots.

Mouth tentacles: Smooth.

Branchiae: Four pairs of branchiae in two well separated groups; three branchiae in each group in transverse row, the fourth branchia in short distance behind the outer one of the three.

Paleae: Small with filiform tips.

Special features: Lower lip enlarged.

Pygidium: With two lateral cirri.

Tube: Thin layer of organic secretion incrusted with shell and plant fragments, some sand, rarely mud.

Distribution

Entire Norwegian coast; 20–180 m (Holthe 1986a).

Similar species

The presence of enlarged lower lip, in combination with paleae and short abdomen (8 uncinigers), makes it unlikely to confuse adult complete specimens of Lysippe fragilis with any other Ampharetidae in Norwegian waters.

Sources

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

Wollebaek A (1912 (for 1911 year)). Nordeuropaeiske annulata Polychaeta I. Ammocharidae, Amphictenidae, Ampharetidae, Terebellidae og Serpulidae. Skrifter utgit av Videnskapsselskapet i Kristiania. I, Matematisk-naturvidenskabelig klasse, year 1911 part 2 no 18: 1-144. http://biodiversitylibrary.org/page/12042491

Personal observations, Alvestad T.