Melinnopsis arctica can be up to 25 mm long. It can be found around Svalbard at depths between 60 and 1800 meters.

Type locality

Franz Josef Land (Queen Victoria Sea, 82o14’N 52o10’E, 165 m; 78o33’ 63o10’E, 363 m; 79o11’N 69o55’E, 480 m).

Key characters

Measurements: Up to 25 mm long.

Number of thoracic chaetigers: 16

Number of thoracic uncinigers: 12

Number of abdominal uncinigers: About 27.

Prostomium: With well-defined anterior and posterior parts, separated by pair of deep transverse nuchal grooves that nearly meet mid-dorsally. No eyespots.

Mouth tentacles: One long, thick muscular tentacle with small round papillae, and several short smooth tentacles.

Branchiae: Four pairs of branchiae in two groups connected at bases; anteriormost pair thicker than other pairs.

Postbranchial hooks: Absent.

Postbranchial depression: Unknown.

Dorsal crest: Absent.

Special features: Aciculate neurochaetae on thoracic chaetiger 4 often missing.

Pygidium: Without lateral cirri.

Tube: Made of mud.

Distribution

Svalbard; 61–1765 m (Jirkov 2001).

Similar species

The absence of postbranchial hooks and dorsal crest, in combination with the shorter body, it has 16 thoracic chaetigers and about 27 abdominal uncinigers compared to 18 thoracic chaetigers and more than 40 abdominal uncinigers for other melinnids, makes it unlikely to confuse adult complete specimens of Melinnopsis arctica with any other Melinnidae in Norwegian waters.

Sources

Annenkova NP (1931). Zur Polychaetenfauna von Franz-Joseph-Land (Melinnexis gen. nov. arctica sp. nov.). Zoologischer Anzeiger 95(9/10): 269-272.

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.