Parvamussium cristatellum (Dautzenberg & Bavay, 1912)

Dijkstra, Henk H. & Maestrati, Philippe, 2010, Pectinoidea (Mollusca, Bivalvia, Propeamussiidae, Entoliidae and Pectinidae) from the Austral Islands (French Polynesia), Zoosystema 32 (2), pp. 333-358 : 336-338

Parvamussium cristatellum

( Dautzenberg & Bavay, 1912)

Amussium cristatellum Dautzenberg & Bavay, 1912: 36 , pl. 28, figs 5-8 (nomen novum for Pecten (Amussium) cristatum [sic] Bavay, 1905: 187, pl. 17, fig. 2a-c, non Pecten cristatus Bronn, 1828 ).

Parvamussium cristatellum – Dijkstra 1991: 13, figs 28-32. — Dijkstra & Marshall 1997: 80, pl. 3, figs 4-8, pl. 4, figs 1, 2; 2008: 7, figs 5, 6A-D [references, type data, supplementary description, distribution]. — Dijkstra & Maestrati 2008: 86 [distribution].

MATERIAL EXAMINED. — Andaman Islands . Lectotype lv ( ZSI M3360 /1, designated by Dijkstra & Kastoro [1997: 261]).

Marotiri. BENTHAUS, stn DW 1884, 27°54’S, 143°33’W, 570-620 m, 3 lv, 4 rv. — Stn DW 1885, 27°52’S, 143°33’W, 700-800 m, 1 lv. — Stn DW 1887, 27°52’S, 143°33’W, 750-1000 m, 1 lv.

Banc Nord-Est Rapa. BENTHAUS, stn DW 1903, 27°27’S, 144°04’W, 400-800 m, 1 rv.

Récif Neilson. BENTHAUS, stn DW 1919, 27°04’S, 146°04’W, 140-390 m, 1 rv. — Stn DW 1923, 27°01’S, 146°05’W, 360-840 m, 3 lv, 5 rv. — Stn DW 1924, 27°01’S, 146°05’W, 340-800 m, 2 lv, 14 rv. — Stn DW 1925, 27°00’S, 146°05’W, 560-790 m, 6 rv.

Tubuai. BENTHAUS, stn DW 1957, 23°19’S, 149°29’W, 558-1000 m, 2 rv. — Stn DW 1961, 23°21’S, 149°34’W, 470-800 m, 1 rv.

Rurutu, Mont Lotus. BENTHAUS, stn CP 1989, 22°36.2’S, 151°00.0’W, 456 m, 1 lv.

Rurutu. BENTHAUS, stn DW 1998, 22°25’S, 151°22’W, 250-302 m, 2 lv. — Stn DW 1999, 22°25’S, 151°22’W, 270-500 m, 1 lv. — Stn DW 2000, 22°25’S, 151°22’W, 270-480 m, 8 lv, 3 rv. — Stn DW 2001, 22°27’S, 151°20’W, 200-550 m, 1 rv. — Stn DW 2003, 22°28’S, 151°19’W, 250-330 m, 2 lv, 2 rv.

DISTRIBUTION. — Southeastern Africa, Andaman Islands, Indonesian Archipelago, Solomon Islands (Dijkstra 2001: 83; Dijkstra & Maestrati 2008: 87); Lord Howe Ridge ( Dijkstra & Marshall 2008: 7), Kermadec Islands, New Caledonia, Vanuatu, Fiji Islands, Wallis and Futuna. Depth range 330-510 m (alive). Now also Austral Islands (new record), only single valves at 140-750 m depth.

REMARKS. — The present material is rather variable in sculpture of the left valve. The radial ribs are weak to prominent and closely to widely spaced. The commarginal lamellae are more widely spaced in the central part of the disc to more closely arranged near the periphery. Internal ribs also vary in number (10 to 12, usually 10, with one or two interstitial rudimentary ones). This variation is also observed in other studied material (MNHN) from the tropical Indo-Pacific. All shell characters are similar to the type material.