Pascahinnites coruscans coruscans (Hinds, 1845)

Dijkstra, Henk H. & Beu, Alan G., 2018, Living Scallops of Australia and Adjacent Waters (Mollusca: Bivalvia: Pectinoidea: Propeamussiidae, Cyclochlamydidae and Pectinidae), Records of the Australian Museum (Rec. Aust. Mus.) 70 (2), pp. 113-330 : 251-253

Pascahinnites coruscans coruscans (Hinds, 1845)

Figs 72H–I, 73, 74E –F

Pecten coruscans Hinds, 1845: 61 , pl. 17, fig. 3; Reeve, 1853: sp. 149 (not sp. 143; Reeve, 1853, errata), pl. 33, fig. 149; Küster & Kobelt, 1888: 259, pl. 67, fig. 9.

Pecten cuneolus Reeve, 1853 : sp. 131, pl. 29, fig. 131.

Pecten schmeltzii [“Dunker ms”] Kobelt in Küster & Kobelt, 1888: 272, pl. 71, figs 5–6.

Pecten sulphureus [“Dunker ms”] Kobelt in Küster & Kobelt, 1888: 276, pl. 72, figs 5–6 (junior primary homonym of Pecten sulphureus of Bosc, 1802, and of Lamarck, 1819).

Pecten kermadecensis “Watson ” [sic].– Oliver, 1911: 527; Oliver, 1915: 554 (misidentification as P. kermadecensis E.A. Smith, 1885 ).

Chlamys cellularis Oliver, 1915: 554 , pl. 12, fig. 46.

Pecten eucosmia Turton, 1932: 222 , pl. 57, fig. 1549.

Chlamys coruscans (Hinds) .–Dautzenberg & Bouge, 1933: 426; Waller, 1972a: 231, pl. 1, figs 1–19, figs 2, 12, 14, table 2; Kilburn & Rippey, 1982: 171, pl. 38, fig. 10; Dijkstra, (1983–1994) 1984: 9, figs; Dijkstra, 1989: 12, figs; Dijkstra, 1990: 3, figs; Dijkstra et al., 1989: 24; Rombouts, 1991: 10, pl. 23, figs 7–7b; Lamprell & Whitehead, 1992: [26], pl. 8, fig. 47; Dijkstra & Marshall, 1997: 99, pl. 8, figs 7–10; Brook & Marshall, 1998: 212; Dijkstra, Drivas & Jay, 1998: 5, fig. 3.

Chlamys schmeltzi (“Dunker”) [sic].– Kira, 1962: 137, pl. 49, fig. 10.

Chlamys (Argopecten) coruscans coruscans (Hinds) .– Dijkstra, (1983–1989) 1983: 3, figs.

Bractechlamys schmeltzi (“Dunker”) [sic].– Wang, 1983b: 531–534, figs 4–7.

Bractechlamys schmeltzii (Kobelt) .–Bernard et al., 1993: 50.

Bractaechlamys [sic] coruscans (Hinds) .–Hayami, 2000: 905, pl. 450, fig. 41, unnumbered figs pp. 904–905.

Semipallium coruscans coruscans (Hinds) .–Dijkstra & Kilburn, 2001: 294, figs 31–32; Raines & Poppe, 2006: 236–237 upper figs; pl. 186, figs 1, 4–6, 8–9.

Pascahinnites coruscans coruscans (Hinds) .– Paulay, 2003: appendix (not paginated); Dijkstra & Marshall, 2008: 51, figs 35, 48A, D; Dijkstra & Moolenbeek, 2008: 20; Spencer et al., 2009: 198; Dijkstra & Maestrati, 2010: 346; Huber, 2010: 209; Raines, 2010: 630, pl. 1006, figs 1–2; Dijkstra, 2013: 73, pl. 19, figs 3a–d.

Bractechlamys coruscans (Hinds) .–Xu & Zhang, 2008: 85, figs 236a–d.

Pascahinnites coruscans (Hinds) .–Dijkstra & Maestrati, 2013a: 371.

Comments on synonymy. For remarks on synonymy see Bavay (1905b: 30; Pecten cuneolus Reeve and P. schmeltzii Dunker ), Waller (1972a: 233; P. cuneolus Reeve and P. sulphureus Dunker ), Kilburn & Rippey (1982: 171, 216; P. eucosmia Turton ) and Dijkstra & Marshall (1997: 101; Chlamys cellularis Oliver ).

Type data. Pecten coruscans Hinds : lectotype (pr) NHMUK19709 ( Waller, 1972a: 231). Type locality: Port Anna Maria, Nukuhiva , Marquesas Islands , 13 m.

Pecten cuneolus Reeve : lectotype (pr) NHMUK1969140 ( Waller, 1972a: 231). Type locality: “Durban, Natal”.

Pecten schmeltzii Küster & Kobelt : holotype LMA (not traced). Type locality: “ Viti-Inseln ” [ Fiji Islands ].

Pecten sulphureus Küster & Kobelt : holotype (pr) ZMB Moll.114.609, H 10.0, L 9.0 mm. Type locality: “Viti-Inseln” [ Fiji Islands ] (Dijkstra & Köhler, 2008: 42, fig. 4d).

Chlamys cellularis Oliver : holotype (lv) CMC M.688. Type locality: beach, Sunday [= Raoul] Island, Kermadec Islands .

Pecten eucosmia Turton : holotype (pr) OUZM Turton

No. 1549. Type locality: Port Alfred , Zululand, South Africa .

Comments on type data. Dijkstra & Köhler (2008: 41) stated that the description of Pecten schmeltzii was based explicitly on a single specimen in Loebbecke’s collection, now in LMA. This is therefore considered to be the holotype. Dijkstra & Köhler (2008: 41, fig. 4g) pointed out that other specimens were distributed by Godeffroy under Dunker’s manuscript name, but not all are conspecific; several specimens in ZMB belong in this category, and are not type material .

The figured type specimen of Pecten sulphureus is present in the systematic collection of the ZMB (10 May 1989). Bavay also examined this specimen (as stated on the label) and treated it as a junior synonym of Pecten coruscans .

Additional material examined. — AUSTRALIA: QUEENSLAND: GBR, Yule Detached Reef, 11°59'S 143°58'E, S end, dead (1 v, C.332596); Reef 13-119, S end, 13°40'S 144°08'E, dead, 5–13 m (1 v, C.332581); No. 5 Sandbank Reef (13-120),SW end, 13°45'S 144°16'E,dead, 8–10 m (1 v,C.332598);GBR,Carter Reef, 14°32'S 145°35'E, inside reef, off “Platform Bommie”, dead, 18 m (1 v, C.332594); off Lizard Island, Carter Reef, 14°33' S 145°36'E, dead, 1–2 m (1 pr, C.332595); E of Lizard Island, Yonge Reef, outside N end, 14°35'S 145°37'E, alive (1 pr, C.344021); Yonge Reef, E of Lizard Island, outer face, N end, 14°35'S 145°37'E, dead, 15–17 m (5 v, C.160956); Lizard Island, SW end of South Island, 14°42'S 145°27'E, dead, 9–12 m (1 v, C.161015 [in part]);No. 9 Ribbon Reef, NW end,lagoon, 14°57'S 145°42'E,dead, 9–11 m (1 v, C.157592); Michaelmas Cay, 16°36'S 145°59' E, dead (6 v, C.332580); Swain Reefs, Sanctuary Reef, 22°03'S 152°40'E, dead, 6–14 m (1 v, C.332582); GBR, Capricorn Group, Tryon Island, 23°15'S 151°47'E, dead (1 pr, C.332576); Capricorn Group,North West Island, 23°18'S 151°42'E,alive (1 pr, C.332577);Capricorn Group, Wilson Island, 23°18'S 151°57' E, alive (many, C.303772); Capricorn Group, Wilson Island, N side, 23°18' S 151°57'E,alive (1 pr,C.344020);Capricorn Group, Heron Island, off middle of island on N side, 23°26'S 151°57'E, alive (1 pr, C.344019); Capricorn Group,Wistari Reef, 23°28'S 151°53'E,alive (2 pr, C.332575;1 pr,C.302343);Bunker Group, off Lady Musgrave Island, 23°54'S 152°25'E, alive, 47 m (1 pr, C.332578); Alexandra Head, 26°40'S 153°07'E, dead(1 v,C.332579). WESTERN AUSTRALIA: Rowley Shoals, Mermaid Reef, 17°10' S 119°37'E, NE corner, dead, 12 m (1 pr, ZMA Moll.146210).— KENYA:Watamu, 3°23'S 40°0'E,alive, 3 m (1 pr, ZMA Moll.139603). SEYCHELLES: Mahé Island, North Point, 4°33'S 55°27' E, alive, 13 m (1 pr, ZMA Moll.143609). RÉUNION: Cap la Houssaye, 21°00'S 55°14'E, alive, 4 m (1 pr, ZMA Moll.142140). MOZAMBIQUE:Inhaca Island, 26°01'S 32°58'E,alive, 12 m (1 pr, ZMA Moll.139896). CHRISTMAS ISLAND:Flying Fish Cove, 10°30'S 105°40'E,dead, 12 m (1 pr, ZMA Moll.146210).— JAPAN: Okinawa,Maeda Misaki,alive, 4 m (1 pr, ZMA Moll.144333).— MARSHALL ISLANDS :KwajaleinAtoll, 9°15'N 167°30'E, ocean side west reef, alive, 9 m (3 pr, ZMA Moll.145878); Majuro Atoll, 7°05'N 171°08'E, alive, 1–2 m (1 pr, ZMA Moll.139739). TUVALU: Niutao,W Channel, 6°07'S 177°17' E,dead, 9 m (1 v, C.167701; 1 v, C.167702). CORAL SEA: Osprey Reef, 13°53'S 146°31'E, alive, 10–17 m (1 pr, C.344023); Osprey Reef, SE end, outer face, 13°59' S 146°40' E, dead, 8–15 m (1 v, C.332591); North East Herald Cay, 16°56'S 149°11'E, dead (46 v, C.332574); North East Herald Cay, 16°56'S 149°11' E, dead (1 v, C.332585); North East Herald Cay, 16°56'S 149°11'E, dead, 4 m (3 v, C.333758); Marion Reef, 19°07'S 152°23'E, dead (1 v, C.357991); Chesterfield Islands , 19°28'S 158°27'E, alive, 44–45 m (1 pr, ZMA Moll.142149); Kenn Reef, 21°15'S 155°44'E, dead (2 pr, C.332586); Saumarez Reef, 21°50'S 153°39' E, dead, 12–15 m (1 v, C.332597); Saumarez Reef, 21°52'S 153°27'E,dead, 13 m (1 v,C.157592);Saumarez Reef, 21°52'S 153°37'E,alive, 9–12 m (1 pr, C.157593). — FIJI ISLANDS : Viti Levu, Nadi Bay, 16°57'S 178°47'E, dead, 9–35 m (15 v, C.332588); Viti Levu, Nadi Bay, 16°57'S 178°47'E, dead (1 v, C.332589); S Viti Levu, Deuba, 18°15'S 178°05'E, dead (9 v, C.332590). — NEW CALEDONIA: Koumac, 20°39.7' S 164°14.9'E, alive, 15 m (1 pr, ZMA Moll.139675); Loyalty Islands ,Lifou Island,Doking, 20°42'S 167°10'E,alive, 0–1.5 m (1 pr,C.344022); Loyalty Islands ,Lifou, 20°53'S 167°13'E,dead (15 v,C.332587); Loyalty Islands ,Lifou Island, behind Cap des Pins, 21°04'S 167°28'E, dead (1 v, C.332599); off Nouméa, Goeland Reef,S point, 22°16'S 166°26'E,alive, 1 m (2 pr, ZMA Moll.142123).—LINE ISLANDS :Christmas Island, Bay of Wrecks, 1°50'N 157°20' W, alive, 9 m (2 pr, ZMA Moll.142087).— SAMOA ISLANDS :Upolu Island,Mulinuu,Apia, 13°48'S 171°45'W, alive, 0.6 m (13 v, ZMA Moll.142089).—SOCIETY ISLANDS : NW Moorea, Tiahura Island, 17°29'S 149°55' W, dead, 8–10 m (6 v, C.167696; 3 v, C.167695; 1 pr + 3 v, C.167697).—TUAMOTU ISLANDS : Arutua Atoll, 15°15'S 146°45'W, alive, 1 m (14 pr, ZMA Moll.141200). —SOCIETY ISLANDS : Huahine Island, Tefarerii, 16°45'S 151°0' W, alive, 0.5–2 m (6 pr, ZMA Moll.142107); NW Moorea Island, Tiahura Islet, E side, 17°29'S 149°55' W, dead (1 v, C.332592); NE Moorea Island, Point Aroa ou de Tiaia, 17°28'S 149°46'W, dead (1 v, C.332593); W Moorea Island, Paevaeva, 17°32'S 149°53'W, dead, 4–11 m, on outside of reef, 2 v (2 v, C.344025).— NEW ZEALAND: Kermadec Islands , Raoul Island, 29°15'S 177°52'E, dead (9 v, C.300125). TASMAN SEA:Middleton Reef,NE outer slope, 29°26'S 159°08' E,dead, 6–13 m (1 v,C.332584); Middleton Reef,S side, 29°29.10'S 159°08.10' E, dead, 10 m (1 v, C.384095);Elizabeth Reef, NE slope, 29°55'S 159°04'E, dead, 10–18 m (1 pr, C.157589); Elizabeth Reef, W outer reef slope, 29°57'S 159°01'E, alive, 15 m (1 pr, C.332583); Elizabeth Reef, W outer reef slope, 29°57.2'S 159°01.2'E,dead, 12 m (1 v, C.357992);Lord Howe Island, Admiralty Islands , Roach Island, 31°30'S 159°04'E, alive, 25 m (1 pr, C.344024); off NE side, 31°31'S 159°05'E, 27 m, dead (1 v,C.300124); 31°54.2'S 159°07.8' E,dead (1 pr, C.027753; 3 v, C.059651); 31°54.2'S 159°07.8'E, dead (4 v, C.059652); Erscott’s, Hole, 31°55'S 159°08.3'E, lagoon, dead, 3 m (1 v, C.157580); Erscott’s, Hole, 31°55'S 159°08.3'E, lagoon, dead, 8 m (1 v, C.300126); Lord Howe Rise, 31°38.2'S 159°03' E, dead, 44 m (1 v, C.300123;1 v,C.160968).—MARQUESAS ISLANDS :Tahuata Island, 9°58' S 139°05'W, dead, 48 m (1 pr, ZMA Moll.144622).

Pascahinnites coruscans hawaiensis (Dall, Bartsch & Rehder, 1938) : — HAWAIIAN ISLANDS : Oahu, Ewa Beach, 21°18'N 158°01'W, alive, 6 m (4 pr, ZMA Moll.144055); Oahu, Waikiki Beach, 21°17'N 157°52'W, alive, 0.8 m (3 pr, ZMA Moll.140961). —JOHNSTON ISLAND: 16°45'N 169°32'W, in lagoon, alive, 6 m (4 pr, ZMA Moll.144059) .

Description. Shell small, most specimens 10–15 mm high, a few larger, to 23.8 mm (Huber, 2010); subcircular to more elongate, almost equivalve, equilateral (juvenile) to more prosocline (mature), right valve somewhat more convex than left, auricles unequal, umbonal angle c. 90°; colour highly variable, most specimens whitish, cream or tawny, with opaque white, red or brown maculations; a few specimens uniform bright yellow, purplish or orange.

Both valves sculptured with 14–15 primary radial plicae, commencing in early growth stage (c. 0.5 mm), with 50–70 (most specimens with c. 60) squamose secondary radial riblets on and between plicae, giving plicae a tripartite or fasciculate appearance towards ventral margin. Antimarginal microsculpture in pre-radial stage, replaced by intercostal shagreen microsculpture in radial stage on disc and auricles. Anterior auricles much larger than posterior, with 5–8 prominent, unevenly developed radial riblets; riblets narrower and weaker on posterior auricles. Postero-dorsal margin somewhat declined. Byssal fasciole broad, byssal notch shallow. Functional ctenolium with 4–6 teeth. Resilifer narrowly triangular. Hinge with weak resilial teeth and more prominent dorsal teeth. Interior plicate.

Dimensions. Illustrated specimen: QLD, GBR, Capricorn Group, Wistari Reef (AM C.332575): rv: H 14.9, L 15.4 mm; lv: H 14.7, L 15.1 mm; D 5.1 mm.

Habitat. Living in the intertidal and littoral zones (to c. 30 m), most specimens byssally attached to corals or rocks or amongst coral rubble on soft sediment (sand).

Distribution. Throughout the (sub)tropical Indo-West Pacific from East Africa (except the Red Sea), Seychelles, Mauritius, Réunion, Maldives, Cocos-Keeling Islands , Christmas Island, southern Japan, China, Philippines, Indonesia, western and eastern Australia, eastwards to the Marquesas Islands , Tuamotu Archipelago and Austral Islands ( French Polynesia) and Pitcairn Island (Waller, 1972: 234–236; Raines & Poppe, 2006: 236); Africa to Hawaii Islands , 0–45 m (Huber, 2010: 209); Mozanbique, 15 m, South Africa, 5–20 m (Dijkstra & Kilburn, 2001: 295–296); Philippines, 3 m (Dijkstra, 2013: 74); Vanuatu, 5–7 m (Dijkstra & Maestrati, 2012: 400); Austral Islands , 2–52 m (Dijkstra & Maestrati, 2010: 346). Maximum depth range of live-taken specimens is from the intertidal zone to 60 m (unpublished data, HHD). Present specimens from Australia alive at 47 m.

Remarks. Dijkstra & Marshall (2008: 51) pointed out that Pascahinnites coruscans is distinctive among Recent Pectinidae in having a primary tripartite radial sculpture, each tripartite costa flanked by 1 or 2 intercostal radial riblets, and shagreen microsculpture. Unlike Pascahinnites pasca (Dall, 1908) from Easter Island, P. coruscans lives byssally attached rather than cemented by the right valve.

Pascahinnites coruscans hawaiensis , a closely related subspecies from the Hawaiian Islands and Johnston Island, differs from P. coruscans coruscans in having 14–15 primary radial plicae (15–17 in P. coruscans coruscans ), somewhat smaller auricles, a narrower umbonal angle, 4–5 posterior auricular denticles rather than 3 more prominent dorsal teeth, and a weaker colour pattern.

Pascahinnites coruscans material from western and eastern Australia is morphologically identical to the type material .

Oliver (1911: 527; 1915: 554) recorded one valve of Pascahinnites coruscans coruscans of Pleistocene age from Deyrell Islet, Kermadec Islands (Dijkstra & Marshall, 1997: 101), and Taylor (1978) recorded Pleistocene fossils from Aldabra atoll, Indian Ocean. Fossil records of Pascahinnites coruscans hawaiensis of probable Pleistocene age were reported by Waller (1972a: 234) from Midway Island, in the Hawaiian chain. No fossils of Pascahinnites coruscans are known from Australia.