Ampharete acutifrons can be up to 80 mm long. It can be found along the entire Norwegian coast and Svalbard, but it is more common in the north, at depths between 4 and 328 meters.

Type locality

East Greenland

Key characters

Fig. 1. Transition between thorax and abdomen. nrp: neuropodium ntp: notopodium. Arrows denote neuropodial dorsal cirri

Fig. 2. Anterior end. br: branchiae, pa: paleae, pr: prostomium

Measurements: Up to 80 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 groups separated by distance equal to one to two branchial base diameters; three branchiae in each group in transverse row, fourth branchia behind middle one of the three; branchial bases on each side fused

Paleae: Long with filiform tips, 10–30 chaetae on each side

Special features: Last two thoracic and all abdominal segments with long cirrus above each neuropodium

Pygidium: With two long lateral cirri and several long cirriform papillae

Tube: Straight and cylindrical, lined with thin layer of organic secretion and covered by thick and loose layer of mud and sand

Distribution

Entire Norwegian coast and Svalbard; more common in the north; 4–328 m (Jirkov 2001). 

Remarks

Holthe (1986a) reports the species to occur down to 2000 m. This depth is questionable, at least in Norwegian waters.

Similar species

The presence of long cirri above the last two pairs of thoracic neuropodia, in combination with the long cirriform pygidial papillae, makes it unlikely to confuse adult complete specimens of Ampharete acutifrons with any other Ampharetidae in Norwegian waters.

Sources

Grube AE (1860). Beschreibung neuer oder wenig bekannter Anneliden. Fünfter Beitrag. Archiv für Naturgeschichte, Berlin 26 (1): 71-118, plates III-V. http://www.biodiversitylibrary.org/page/7153453#page/79/mode/1up

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.

Posterior end. lc: lateral cirri, nrp: neuropodium, p: pygidial papillae. Arrows denote neuropodial dorsal cirri

Fig. 5. Abdominal neuropodium. ndc: neuropodial dorsal cirrus. nrp: neuropodium