Sosane wireni (Hessle, 1917)

Imajima, Minoru, Reuscher, Michael G. & Fiege, Dieter, 2013, Ampharetidae (Annelida: Polychaeta) from Japan. Part II: Genera with elevated and modified notopodia, Zootaxa 3647 (1), pp. 137-166 : 156-157

Sosane wireni (Hessle, 1917)

( Figs. 12 A–G; 17C)

Specimens examined. Moroiso Bay, 35°09.4'N, 139°36.8'E, 30 m, St. 2, 3.1979 (1cs). Off Shimoda, 34°38.4'N, 138°56.3'E – 34°38.5'N, 138°56.5'E, 37–39 m, St. 12, 9.1987 (1cs). Kushimoto, 33°27.2'N, 135°45.4'E – 33°27.2'N, 135°45.6'E, 19–27 m, St. 14, 7.1978 (3cs); 33°29.1'N, 135°51.0'E – 33°29.2'N, 135°51.2'E, 34 m, St. 9, 7.1978 (1cs); 33°27.4'N, 135°44.2'E – 33°27.3'N, 135°44.0'E, 43–48 m, St. 15, 7.1978 (2cs).

Description. Length 5 to 8 mm, width 0.8 to 1 mm. Prostomium with middle lobe delimited by incision, without glandular ridges or eyes ( Fig. 12 A, B). Buccal tentacles unknown. Lower lip not crenulated. Four pairs of cirriform branchiae ( Fig. 12 A); 3 pairs of branchiae in triangular arrangement in segment II, and 1 pair in segment IV; branchial groups separated by median gap of more than one branchial width; branchiae of segment II inserted in anteromedian position of triangle, branchiae of segment III in outermost position of triangle, branchiae of segment IV in innermost position of triangle, branchiae of segment V emerging next to notopodia of segment IV ( Fig. 17 C); branchiae in smallest specimen ciliated, without cilia in bigger specimens. Chaetae in segment II absent. Notopodia with limbate capillary notochaetae from segment III, present in 15 segments ( Fig. 12 C). Notopodia in third-to-last thoracic unciniger elevated, basally inflated, apically bifid, not connected by dorsal ridge ( Fig. 12 D, E); notochaetae of modified unciniger in fan-like arrangement on convex side of notopodia, with indistinctly hirsute tips ( Fig. 12 F). Neuropodial tori with uncini from segment VI, present in 12 thoracic uncinigers. Cirri and papillae in thoracic parapodia absent. Continuous ventral shields present to thoracic unciniger 8 or 9. Two intermediate uncinigers. Nine 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 cirriform anal cirri. Thoracic and abdominal uncini with crest of numerous teeth above rostral tooth and basal prow ( Fig. 12 G).

Remarks. There are two different species, Sosane wireni (Hessle, 1917) (described as Sosanopsis wireni ) and Sosane wireni Caullery, 1944 . The synonymy of Sosane and Sosanopsis would leave S. wireni Caullery, 1944 as homonym of Hessle’s species. However, Caullery’s species description of S. wireni and S. fauveli Caullery, 1944 seem to be based on a misconception of the genus Sosane since both of Caullery’s species do not have the characteristically modified segment. We think that Caullery’s species may belong to Lysippe . A re-examination of Caullery’s material was not possible because collections were being moved between the natural history museums of Amsterdam and Leiden during the time of this study.

Distribution. North Sea, Barents Sea, Laptev Sea (Holthe 1986a, Hartmann-Schröder 1996), New England (Hilbig 1994), California (Hilbig 2000). Newly recorded from Sagami Bay and Kushimoto, Pacific coast of Honshu, in 19– 48 m.

Figures

FIGURE 12. Sosane wireni. A: anterior end, dorsal view, 50 x, B: anterior end, dorsolateral view, 65 x, C: limbate capillary chaeta, 613 x, D: thoracic uncinigers 8 – 12 and intermediate unciniger 1, lateral view, 50 x, E: thoracic unciniger 10, anterior view, 94 x, F: modified notochaeta of thoracic unciniger 10, 1045 x, G: thoracic uncinus, 1320 x.

FIGURE 17. ID-cards of reported species with modified notopodia. A: Sosane trigintaduo sp. nov., B: Sosane uebelackerae sp. nov., C: Sosane wireni, D: Tanseimaruana boninensis gen. et sp. nov., E: Zatsepinia jirkovi sp. nov., F: Zatsepinia rittichae. Abbreviation: V = velum, other abbreviations as shown in figure 16.