Propeamussium watsoni (Smith, 1885)

Dijkstra, Henk H. & Maestrati, Philippe, 2013, Pectinoidea (Bivalvia: Propeamussiidae, Entoliidae and Pectinidae) from the Tarava Seamounts, Society Islands and the Tuamotu Archipelago (French Polynesia), Zoosystema 35 (3), pp. 361-375 : 362

Propeamussium watsoni (Smith, 1885)

Amussium watsoni Smith, 1885: 309 , pl. 22, figs 8-8c.

Propeamussium watsoni – Dijkstra 1995: 24, figs 27-30, 123-124 (synonymy, references, type data, distribution, description). — Dijkstra & Maestrati 2010: 334 .

MATERIAL EXAMINED. — New Guinea. Northeast, 1957 m, lectotype spm ( BMNH 1887.2.9.3307). Tarava Seamounts. Tarasoc, stn DW 3339, 18˚23’S, 154˚09’W, 778-1050 m, 1 lv ; stn DW 3343, 17˚51’S, 154˚04’W, 763-812 m, 19 lv, 8 rv. Tuamotu Archipelago. Tarasoc, stn DW 3377, 15˚38’S, 146˚53’W, 780-825 m, 1 lv; stn DW 3378, 15˚38’S, 146˚51’W, 887-890 m, 7 lv, 2 rv; stn DW 3379, 15˚38’S, 146˚51’W, 800 m, 2 lv; stn DW 3381, 15˚41’S, 146˚56’W, 830-988 m, 1 rv.

DISTRIBUTION. — Northern Indian Ocean, southern Japan, Papua New Guinea, New Caledonia, Vanuatu, and Austral Islands ( Dijkstra & Maestrati 2010: 335). Depth range 650-1300 m (alive). Now also Society Islands and Tuamotu Archipelago (new record), only single valves at 763-1050 m (maximum depth range).

REMARKS

The present specimens are similar to the type material, although the radial riblets of the left valve are more developed on the central part of the disc (typical only in early growth stage) and the internal ribs are more closely spaced and almost regularly developed in size to the ventral margin (typical shorter and more irregularly development)and in addition greater in number (eight with one or two shorter riblets laterally, typical six with one shorter riblet laterally).Other conchological characters are identical to the type material.