Ampharete acutifrons
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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
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Fig. 1. Transition between thorax and abdomen. nrp: neuropodium ntp: notopodium. Arrows denote neuropodial dorsal cirri
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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.
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Posterior end. lc: lateral cirri, nrp: neuropodium, p: pygidial papillae. Arrows denote neuropodial dorsal cirri
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Fig. 4. Uncini from abdominal neuropodium
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Fig. 5. Abdominal neuropodium. ndc: neuropodial dorsal cirrus. nrp: neuropodium
Siden siteres som:
Alvestad T og Budaeva N (2020). Ampharete acutifrons (Grube, 1860). www.artsdatabanken.no/Pages/299293. Nedlastet <dag/måned/år>