Ampharete falcata can be up to 18 mm long. It is more common in southern Norway but can be found along the entire coast up to at least Troms at depths between 30 to 230 meters. 

Type locality

Bohuslän, Sweden, 50 m.

Key characters

Ampharete falcata. Anterior end. br: branchiae, mt: mouth tentacles, pa: paleae.

Measurements: Up to 18 mm long.

Number of thoracic chaetigers, excluding paleae: 14

Number of thoracic uncinigers: 12

Number of abdominal uncinigers: 12

Prostomium: Trilobed; one pair of eyespots.

Mouth tentacles: Papillose.

Branchiae: Four pairs of branchiae in two widely separated groups; three branchiae in each group in transverse row, fourth branchia behind middle one of the three; branchial bases on each side fused.

Paleae: Short with filiform tips, 6–8 chaetae on each side.

Special features: Anterior three to four abdominal segments with large rounded lobes usually referred to as rudimentary notopodia.

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

Tube: Made of mud with no sand or shell fragments attached.

Distribution

Norwegian coast, more common in the south but reported up to Troms; from 30 m (Holthe 1986a) to 230 m (Jirkov 2001).

Similar species

The large rounded lobes on the anterior abdominal segments, in combination with the short paleae, makes it unlikely to confuse adult complete specimens of Ampharete falcata with any other Ampharetidae in Norwegian waters.

Sources

Eliason A (1955). Neue oder wenig bekannte schwedische Ampharetiden (Polychaeta). Göteborgs Kungliga vetenskaps- och vitterhets-samhälles handlingar (B) 6 (16): 1-17.

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.

Personal observations, Alvestad T.

Ampharete falcata. Transition between thorax and abdomen. ntl: Rudimentary notopodium/neuropodial dorsal lobe. C: Cilia 

Ampharete falcata. Uncini from abdominal neuropodium.