Sosane sulcata Malmgren 1866

Sosane sulcata Malmgren, 1866

(Figs. 9 A–K; 16E)

Sosane sulcata Malmgren, 1866: 368, pl. 26, fig. 79—Hessle 1917: 108–109, fig. 13. Gibbs & Probert 1973: 399–401, fig. 2. Uebelacker 1984: 11–14, figs. 7, 8. Holthe 1986a: 48–50, fig. 17. Hartmann-Schröder 1996: 502. Hayashi & Hanaoka 1997: 385–388, fig. 2.

Specimens examined. Uraga Channel, 35°09.6'N, 139°48.6'E, 33 m, 12.1978 (1cs). Sagami Bay, 35°16.8'N, 139°33.7'E, 12 m, 10.1985 (1cs); 35°11.6'N, 139°34.2'E − 35°11.7'N, 139°33.9'E, 60 m, St.11, 9.1979 (2cs); 35°10.3'N, 139°33.4'E − 35°10.5'N, 139°33.4'E, 147−175 m, 1.1970 (1af); 35°08.1'N, 139°32.9'E − 35°07.6'N, 139°32.8'E, 240−418 m, Rinkai-maru, St. 3, 2.2002 (2af); 35°09.1'N, 139°23.3'E − 35°09.1'N, 139°23.9'E, 478− 490 m, KT-76-3, St. BS1-1, 2.1976 (3af); 35°07.7'N, 139°22.0'E, 800 m, St.W7, 6.1980 (1af); 35°11.7'N, 139°23.0'E, 950 m, St.W6, 5.1980 (1cs); 35°00.3'N, 139°40.2'E 35°00.2'N, 139°40.5'E, 274−300 m, Shin'yomaru, St.5, 10.2003 (2af). Off Kunozan, 34°56.6'N, 138°31.1'E, 80 m, St. 1, 7.1967 (1cs). Kushimoto, SMF 21692, 33°29.2'N, 135°48.4'E − 33°29.4'N, 135°49.2'E, 12−14 m, St. 7, 7.1978 (3cs); 33°27.7'N, 135°44.8'E − 33°27.5'N, 135°44.4'E, 44 m, St. 5, 7.1978 (4cs). Off Akita, 39°47.0'N, 139°54.7'E, 40 m, 8.1981 (2cs). Iyo-nada, 33°35.0'N, 132°12.0'E, 65 m, Toyoshio-maru, St. 1-2, 5.2005 (1cs). Tosa Bay, 33°26.7'N, 133°34.8'E, 46 m, No.2-2, 4.1970 (3cs). Sasebo Bay, 33°05.5'N, 129°40.2'E, 50 m, St. 2, 5.1972 (2cs). Kagoshima Bay, 31°20.6'N, 130°34.6'E, 50− 55 m, St. 8, 1.1974 (1af). Off Tsushima Island 34°16.0'N, 129°31.5'E, 105 m, St. 33, 8.1968 (1af). Chichijima, Ogasawara Islands, 26°58.069'N, 142°09.066'E − 26°57.812'N, 142°09.057'E, 150−152 m, Koyo, St. 13, 10.2008 (1cs). Off Sanriku, 41°25.0'N, 142°18.5'E − 41°24.7'N, 142°19.7'E, 1230−1250 m, KT-69-16, St. 2, 9.1969 (1af).

Description. Length 15 to 26 mm, width 1.8 to 2.2 mm. Prostomium with middle lobe delimited by incision, in trilobed shape, without glandular ridges, with several small eyespots (Fig. 9 A). Buccal tentacles smooth, distally spindle-shaped (Fig. 9 B). Four pairs of cirriform branchiae (Fig. 9 C); 3 pairs of branchiae in transverse row in segment II, 1 pair behind innermost branchiae of transverse row; branchial groups not separated by median gap; branchiae of segment II inserted in innermost position of transverse row, branchiae of segment III inserted in 2nd outermost position of transverse row, branchiae of segment IV in posterior position, branchiae of segment V in outermost position of transverse row (Fig. 16 E). Chaetae in segment II present, slightly longer than following notochaetae, 10–15 per fascicle. Notopodia with limbate capillary notochaetae (Fig. 9 D) from segment III, present in 15 thoracic segments; notopodia of segments III and IV small. Notopodia in third-to-last thoracic unciniger elevated, basally inflated, apically broadly conical (Fig. 9 E, F); notochaetae of modified unciniger with hirsute tips (Fig. 9 G). Neuropodial tori with uncini from segment VI, present in 12 thoracic uncinigers. Two intermediate uncinigers. Ten abdominal uncinigers. Rudimentary notopodia and glandular pads in intermediate and abdominal uncinigers absent. Pinnules without cirri or papillae. Pygidium with terminal anus and 1 pair of ventrolateral anal cirri (Fig. 9 H). Thoracic (Fig. 9 I, J) and abdominal uncini (Fig. 9 K) with three columns of up to 5 teeth each.

Remarks. The position of the 4th pair of branchiae in Sosane sulcata in the anterior transverse row is unusual within the genus Sosane. The fusion of the branchial bases with the dorsum and the origin of the branchiae in segment V are still visible.

Distribution. North Sea (Hessle 1917), Barents Sea, Norwegian Sea, Eastern Atlantic, Mediterranean Sea (Holthe 1986a, Hartmann-Schröder 1996), Gulf of Mexico (Uebelacker 1984), Wakasa Bay in the Sea of Japan (Hayashi & Hanaoka 1997). Newly recorded along the Japanese Pacific coast from off Sanriku between Hokkaido and Honshu, in the north to Kagoshima Bay, Kyushu, in the south, off Chichijima Island in the Pacific, off Akita in the Sea of Japan, and off Tsushima Islands in the Korea Strait, in 12–1250 m.