Scalibregma inflatum Rathke, 1843: 184 –186, pl. IX, figs 15–21.— Furreg 1925: 157 –163, figs C–H.— Støp-Bowitz 1945: 67 – 72, fig. 2; 1948: 25–26, fig. 8.— Mackie 1991: 268 –271, figs 1–10.
Oligobranchus roseus M. Sars, 1846: 91 –94, pl. 10, figs 20–27.
Type localities. Scalibregma inflatum: near Molde, western Norway. Oligobranchus roseus: Florø, western Norway.
Material examined. The Norwegian North-Atlantic Expedition 1876–1878, Norwegian continental shelf break, Sta. 18, 62° 44 'N 1 ° 48 'E, 753 m, 1 spm (ZMBN 2276), identified by Hansen (1882). R/V ‘ Håkon Mosby’ stations: Sta. 82.01. 21.2, Lat: 62.491 Long: 0 1.721, 604 m, 1.1 °C, 21 Jan. 1982, 1 spm; Sta. 83.06.0 2.1, Lat: 62.198 Long: -00.003, 708 m, - 0.3 °C, 0 2 June 1983, 1 spm; Sta. 83.06. 17.3, Lat: 62.593 Long: 0 1.233, 781 m, - 0.9 °C, 17 June 1983, 2 spms; Sta. 84.11. 21.2, Lat: 62.553 Long: 0 1.820, 625 m, - 0.8 °C, 21 Nov. 1984, 3 spms; Sta. 85.01.0 8.1, Lat: 62.525,Long: 0 1.443, 701 m, - 0.9 °C, 8 Jan. 1985, 6 spms; Sta. 86.07. 27.2, Lat: 70.810 Long: - 0 9.728, 886 m, - 0.6 °C, 27 July 1986, 1 spm; Sta. 86.08. 15.5, Lat: 62.610 Long: 0 1.573, 654 m, - 0.9 °C, 15 Aug. 1986, 1 spm; Sta. 86.08. 17.6, Lat: 62.691 Long: 0 1.756, 750 m, - 0.9 °C, 17 Aug 1986, 4 spms. R/V ‘ Jan Mayen ‘ stations: Sta. 808 - 99, Lat: 70.9768 Long: -08.7735, 109 m, 14 Sept. 1999, 17 spms; Sta. 813 - 99, Lat: 71.1068 Long: -09.5877, 514 m, 15 Sept. 1999, 1 spm. Environmental monitoring stations: Sta. OL-02, Lat: 63.49451 Long: 0 5.41986, 822 m, 17 June 2004, 2 spms; Sta. OL-03, Lat: 63.50035 Long: 0 5.36968, 867 m, 17 June 2004, 7 spms; Sta. OL-04, Lat: 63.51289 Long: 0 5.37823, 858 m, 18 June 2004, 3 spms; Sta. OL-05, Lat: 63.50675 Long: 0 5.40527, 828 m, 17 June 2004, 2 spms; Sta. OL-06, Lat: 63.52349 Long: 5.37058, 870 m, 18 June 2004, 4 spms; Sta. OL-07, Lat: 63.52469 Long: 0 5.40486, 843 m, 18 June 2004, 2 spms; Sta. OL-08, Lat: 63.53813 Long: 05.38181E, 852 m, 18 June 2004, 2 spms; Sta. OL-09, Lat: 63.53583 Long: 0 5.40537, 854 m, 18 June 2004, 2 spms; Sta. OL- 10, Lat: 63.53050 Long: 0 5.43927, 810 m, 18 June 2004, 3 spms; Sta. OL- 11, Lat: 63.55031 Long: 0 5.42835, 851 m, 18 June 2004, 6 spms; Sta. OL- 12, Lat: 63.55516 Long: 0 5.36859, 901 m, 19 June 2004, 2 spms; Sta. OL- 13, Lat: 63.56073 Long: 0 5.39664, 883 m, 19 June 2004, 2 spms; Sta. V-06, Lat: 63.50074 Long: 0 5.33366, 913 m, 0 1 June 1998, 6 spms; Sta. V-09, Lat: 65.00138 Long: 0 5.00019, 757 m, 0 1 June 1998, 2 spms.
Remarks. Type material of Scalibregma inflatum is not known to exist. Mackie (1991) gave a redescription of S. inflatum based on specimens from the Sunndalsfjord in western Norway, close to the original type locality. He also confirmed the synonymy of Oligobranchus roseus with S. inflatum after examining a specimen of O. roseus kept at the Zoological Museum, University of Oslo, and presumed to be the material for the original description. M. Sars (1846) described O. roseus, being unaware of Rathke’s description (note p. 94; 1846), but appears later to have accepted the synonymy (M. Sars in G. O. Sars 1872).
The specimens examined in the present study were all collected on the upper slope of the Norwegian continental margin, at depths greater than 600 m, and from Jan Mayen. The specimens agree with the description given by Mackie (1991). The presence of short, acute or bifurcate spines on chaetiger 1–2, as described by Mackie (1991), was confirmed.
Distribution. Scalibregma inflatum is known to have a wide distribution in northern coastal waters. Støp- Bowitz (1945, 1948) reported S. inflatum from a number of localities in Norwegian and Arctic areas in depths from 10 to 200 m. In deeper waters there are scattered records from west Greenland, Spitsbergen and Jan Mayen in 450– 1275 m (Støp-Bowitz 1948). This study confirms the presence of the species in shelf break areas down to about 900 m depths in the Norwegian Sea (Fig. 7 B). The species may seem to have a depth limit at about 1000 m in the Nordic Seas.
Scalibregma inflatum is reported from world-wide areas (Blake 1981). Most probably several species are confounded. Mackie (1991) commented that several descriptions in faunal works from the northeast Atlantic may incorporate S. celticum Mackie, 1991 as well.