Laevichlamys cuneata (Reeve, 1853)

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 : 240-241

Laevichlamys cuneata (Reeve, 1853)

Figs 67D,F, 68, 69F,H

Pecten irregularis G. B. Sowerby II, 1842: 69 , pl. 13, figs 51–52; Reeve, 1852: species 19, pl. 4, fig. 19a; Küster & Kobelt, 1888: 76, pl. 19, fig. 4; Dunker, 1882: 240, pl. 11 fig. 15 (junior primary homonym of Pecten irregularis von Schlotheim, 1813 ).

Pecten cuneatus Reeve, 1853 : sp. 94, pl. 24, figs 94a, 95; Küster & Kobelt, 1888: 74, pl. 19, figs 1–2, pl. 22, fig. 4.

Pecten (Chlamys) irregularis Sowerby. –Dautzenberg & Bavay, 1912: 13.

Chlamys cookei Dall, Bartsch & Rehder, 1938: 90 , pl. 24, figs 1–4.

Chlamys irregularis (Sowerby) .– Kira, 1962: 139, pl. 50, fig. 3; Masuda, 1962: 171, pl. 24, figs 2–3; Kay, 1979: 525, figs 168B–C; Wagner, 1982: 86; Dijkstra, 1991: 31; Dharma, 1992: 84–85, pl. 20, figs 5–5a; Bernard et al., 1993: 48; Dijkstra, (1983–1994) 1993: 8, figs 1–3; Hu & Tao, 1995: 170, pl. 92, fig. 1; Xu, 1997: 68; Wang, 2002: 177, pl. 4, fig. 5; Dharma, 2005: 248, pl. 99, figs 4a–b; Xu & Zhang, 2008: 81, fig. 223.

Chlamys sp. cf. irregularis (Sowerby) .– Waller, 1972a: 238, 239, pl. 2, figs 34–35, fig. 3.

Chlamys (Coralichlamys) irregularis (Sowerby) .– Wang, 1983c: 48, 54, pl. 1, fig. 2; Higo & Goto, 1993: 573.

Chlamys (Chlamys) irregularis (Sowerby) .–Dijkstra, 1990a: 9, 11; Lamprell & Whitehead, 1992: [20], 174, pl. 8, fig.41.

Chlamys (Scaeochlamys) irregularis (Sowerby) .– Rombouts, 1991: 33, pl. 12, fig. 8; Higo et al., 1999: 442.

Laevichlamys irregularis (Sowerby) .– Waller, 1993: 202, 204; Dijkstra, 1997: 320, figs 5–8; Dijkstra, 1998a: 32, pl. 5, figs 1–4.

Laevichlamys brettinghami Dijkstra, 1998b: 246 (unnecessary replacement name for P. irregularis Sowerby ).

Chlamys (Laevichlamys) irregularis (Sowerby) .–Hayami, 2000: 899, pl. 447, fig. 10.

Chlamys brettinghami (Dijkstra) .–Higo et al., 2001: 156, fig. B441 (syntype of Pecten irregularis Sowerby , here designated lectotype).

Laevichlamys cuneata (Reeve) .–Raines & Poppe, 2006: 198, 199, pl. 142, figs 1, 5–6; pl. 151, fig. 4; Dijkstra & Moolenbeek, 2008: 19; Huber, 2010: 207; Raines, 2010: 622, pl. 1002, fig. 3; Dijkstra, 2013: 64, pl. 17, figs 1a–d, 3a–b, pl. 28, figs 3a–b.

Type data. Pecten irregularis Sowerby : lectotype (pr) NHMUK 1950.11.14.39, figured by Sowerby (1842: fig. 51) and Higo et al. (2001: 156, fig. B441), herein designated. Type locality: not indicated. Examined typical specimens are from the Philippine Islands ( AM, HD, MNHN, ZMA) .

Pecten cuneatus Reeve : lectotype (pr) NHMUK2001 0485/1, largest specimen, figured by Reeve (1853: pl. 24, fig. 94a), herein designated. One paralectotype (pr) NHMUK 20010485 /2, figured by Reeve (1853: pl. 24, fig. 95), and one unfigured paralectotype (pr) NHMUK20010485 /3. Type locality: Moluccas, Indonesia.

Chlamys cookei Dall, Bartsch & Rehder : holotype (pr) USNM484166. Type locality: Hawaiian Islands , off the entrance to Honolulu Harbor, Oahu, 11 fathoms [20 m].

Additional material examined. — AUSTRALIA: QUEENSLAND: Torres Strait,off Murray Island, 9°56'S 144°04'E,dead, 9–15 m (2 v, C.161013 [in part]); Torres Strait, Murray Island, 9°56'S 144°04'E, dead (1 pr, C.132190); Torres Strait, Murray Island, 9°56'S 144°04'E, dead (14 v, C.029787); Torres Strait, Murray Island, 9°56'S 144°04'E, dead (5 v, C.029790);Torres Strait, Murray Island, 9°56'S 144°04'E, dead (4 v, C.336882); Cape York Peninsula, Halfway Island, NNW face, 11°23'S 142°57'E, dead, 4–9 m (1 v, C.384097);Long Sandy Reef, NW end, 12°29'S 143°46'E, dead, 10 m (1 v, C.332572); Bligh Reef, on N side of Bligh’s Boat Passage, 12°51'S 143°49'E, dead, 4–18 m (1 pr, C.332571);Ham Cay, 13°02'S 145°52'E, dead, 10–12 m (1 v, C.157605); GBR, Ham Reef, 13°02'S 145°52'E, alive, 6–9 m (2 pr, C.344011); No. 8 Sand Cay, N side, 13°21'S 143°57'E,dead, 15 m (1 v,C.157599);No. 8 Sand Cay, N side, 13°21'S 143°57'E, alive, 15 m (1 pr, C.157601); Reef 13-074, off sandbank, 13°29'S 144°02'E,dead, 7–10 m (2 v,C.332573);Reef 13-119,S end, 13°40'S 144°08'E, dead, 5–13 m (1 v, C.332570; 1 v, C.160957); Reef 13-119, 13°40'S 144°09'E, dead, 3–6 m (1 v, C.336886); No. 5 Sandbank Reef (13-120), SW end, 13°45'S 144°16'E, alive, 8–10 m (3 pr,C.157607);No.5 Sandbank Reef (13-120),S end, 13°45'S 144°16'E, dead, 9–15 m (1 v,C.336884);No.5 Sandbank Reef (13-120),S end, 13°45'S 144°16' E, dead, 3–15 m (1 v, C.336885; 1 v, C.160958); Jewell Reef, SE elbow of reef, 14°24'S 145°24' E, dead, 15–16 m (1 v, C.332569); Jewell Reef, SE corner, 14°24'S 145°24'E, alive, 10–12 m (1 pr,C.344016);off Lizard Island,Carter Reef, 14°33' S 145°36'E,dead, 15 m (1 pr, C.336893); off Lizard Island, Yonge Reef, 14°66.7' S 145°46.7'E, alive (1 pr, C.125135); Yonge Reef, E of Lizard Island, N end, 14°35'S 145°37' E, dead, 15–17 m (1 v,C.336894); E of Lizard Island, Yonge Reef, 14°35'S 145°37'E, alive, 9–17 m (1 pr, C.344014); Lizard Island, North Point, 14°39'S 145°27'E, alive, 3.5 m (2 pr, C.344010); Lizard Island, Macgillivray Cay, NW side, 14°39'S 145°29'E, dead, 6–17 m (2 v,C.332567);Lizard Island,Macgillivray Cay, NW side, 14°39'S 145°29.5'E,dead, 9–15 m (1 v, C.336883; 1 pr, C.336895); Lizard Island, off Rocky Point, 14°40'S 145°26'E,dead, 9 m (1 v,C.161004);Lizard Island,off Point S of Rocky Point, 14°40' S 145°27'E, dead, 6–7.5 m (1 pr, C.336896); Lizard Island, Lizard Head, S side, 14°40' S 145°28'E, alive, 1–2 m (1 pr, C.336892); No Name Reef, SW end, 14°40'S 145°39'E, dead, 15–20 m (1 v, C.332568); between South & Bird Islands , Lizard Island, 14°41' S 145°28'E,dead, 3 m (1 v, C.336891); Lizard Island, No. 1 Bommie, 14°41'S 145°28' E, alive, 0–15 m (1 pr, C.344017); Eyrie Reef, W of Lizard Island, 14°42'S 145°23' E, E reef slope, dead, 3–11 m (1 pr, C.127495); Lizard Island, SW end of South Island, 14°42'S 145°27'E,dead, 9–12 m (6 v,C.161015);Reef 14-151, 14°55'S 145°41' E,dead, 8–13 m (1 v,C.336890);No. 10 Ribbon Reef,SW end, 14°55.5'S 145°42'E,dead, 4.5–18 m (1 v, C.157603; 4 v, C.336887); No. 10 Ribbon Reef, SW end, 14°56'S 145°42' E, dead, 8–10 m (1 v, C.336897);No. 9 Ribbon Reef, NW end, 14°57'S 145°42.5'E, dead, 9–11 m (3 v, C.138330);No. 9 Ribbon Reef, NW end, 14°57'S 145°42.5'E, dead, 11 m (1 v, C.336888); No. 7 Ribbon Reef, NW end, 15°08'S 145°44'E, dead, 6–15 m (1 v, C.336889; 1 v, C.336898); No. 5 Ribbon Reef, 15°21'S 145°46'E, dead, 6 m (1 v, C.336878); Ruby Reef, NW side, 15°44'S 145°47'E, dead, 9–18 m (3 v, C.157611); Endeavour Reef, 15°47'S 145°35'E, dead, 8–10 m (1 pr, C.157606); Pickersgill Reef, 15°50'S 145°34' E, alive (1 pr, C.344009); off Undine Reef, 16°08'S 145°40'E, alive (2 pr, C.336881); Opal Reef, N of Cairns, 16°15'S 145°50'E, dead, 29 m (1 v, C.153554); Low Isles, 16°23'S 145°34'E,dead (1 v, C.133074;1 v,C.161018);Spur Reef,off Cairns, 16°24'S 146°03'E, dead, 6–12 m (4 v, C.336880); Hastings Reef, 16°31'S 146°01' E, dead, intertidal (1 pr, C.153557); Michaelmas Cay, 16°36'S 145°59'E, alive (1 pr, C.097430); Michaelmas Cay, 16°36'S 145°59' E, dead (8 v, C.119509); Green Island, near Cairns, 16°46' S 145°58'E, dead (1 pr, C.332566);Briggs Reef, off Cairns, 16°57'S 146°11'E, dead, intertidal (3 v, C.336879); North Barnard Islands , 17°40'S 146°10' E, dead (1 v, C.009984); Orpheus Island, Pioneer Bay, 18°35'S 146°29'E, alive, 3–4 m (1 pr, ZMA Moll.146236); John Brewer [= Watt] Reef, 18°37'S 147°03'E, dead, subtidal (1 pr, C.132192); off Great Palm Island, 18°43'S 146°37'E, alive (1 pr, C.303770); Wheeler Reef, NE of Townsville, 18°46'S 147°31'E, dead, subtidal (1 pr, C.132191; 1 pr, C.153556); Wheeler Reef, SE side, 18°46'S 147°31'E, dead, 14 m (1 pr, C.332565; 1 v, C.336873); Wheeler Reef, NE of Townsville, N side, 18°46'S 147°31'E, dead, 11 m (1 v,C.336875); Broadhurst Reef, E of Townsville, 18°57'S 147°44'E, dead, subtidal (2 pr, C.131212; 1 pr, C.153551;pr, C.336874); Broadhurst Reef, E of Townsville, 18°57'S 147°44'E, dead, sublittoral (1 pr, C.153552; 1 pr, C.153553); Little Broadhurst Reef, E of Townsville, 18°59'S 147°43'E, dead,subtidal (1 pr,C.132193);Swain Reefs, Mystery Reef, 21°22'S 152°01'E, dead, 4–6 m (2 v, C.148169); Swain Reefs, Mystery Reef, 21°22'S 152°01'E, dead, 6–10 m (1 v, C.336876); Swain Reefs, Reef 21-184, 21°23'S 151°42'E, dead, 10–11 m (1 v, C.336877); GBR, Swain Reefs, Reef 21-184, 21°23'S 151°42' E,beach,alive (1 pr,C.344015);Swain Reefs,Sanctuary Reef, 22°03.8'S 152°40.2'E, alive, 6–14 m (1 pr, C.157608); Capricorn Group, North West Island, SW corner, 23°18'S 151°42'E, dead, 4–5 m (1 v, C.332564); Capricorn Group, One Tree Island, 23°30'S 152°05' E, alive (1 pr, C.332563); Gladstone, 23°51'S 151°16' E, alive (1 pr,C.080130). WESTERN AUSTRALIA: Quobba, at end of road along cliffs from Blowholes, 24°29'S 113°25'E, dead (11 v, WAM 519.91);Point Quobba,behind island, 24°29'S 113°25'E, alive (1 pr, C.160999); Rowley Shoals, approx. 17°10' S 119°20'E, dead, 10–15 m (2 pr, ZMA Moll.146219); off Broome, Rowley Shoals, c. 2–3 ml N of North Passage, NE corner of Clerke Reef, approx. 17°10'S 119°20' E, on outer slope of reef,dead, c. 17 m (1 v, WAM 1323.82); Rowley Shoals, Bedwell Island, Clerke Reef, 17°10' S 119°20' E, dead, beach (2 v + 3 fragm., WAM 499.91); Clerke Reef, SE reef, 17°10'S 119°20'E, dead (4 v + 1 fragm., WAM 498.91);Rowley Shoals,Mermaid Reef, W side, approx. 17°07'S 119°36'E, dead, intertidal (1 v, WAM 497.91); Scott Reef, NE entrance of North Reef, 14°05'S 121°50'E, dead, 10 m (1 pr, ZMA Moll.143828);Scott Reef, eastern North Reef, outer reef, approx. 14°0'S 121°45'E,dead, 9–18 m (4 v, WAM 2895.84); Seringapatam Reef, NE corner, 13°41'S 122°05'E, dead, 10 m (1 pr, ZMA Moll.143827); Seringapatam Reef, E side, 13°41'S 122°05'E, dead, 10 m (1 pr, ZMA Moll.143833); Cartier Island, N side, 12°31' S 123°29'E, dead, 12 m (1 pr, ZMA Moll.143829);Ashmore Reef, approx.mid-northern coast, 12°17'S 123°02'E, outer reef slope, dead, 12 m (1 v, NTM P010139);Ashmore Reef, NE corner, 12°14'S 123°05'E, dead, 15–18 m (1 pr, ZMA Moll.145818). NORTHERN TERRITORY: Port Darwin, beach, 12°23'S 130°44' E, dead (1 v, ZMA Moll.143819). — JAPAN: Kii Prefecture, Wakayama,alive, 28–32 m (2 pr, ZMA Moll.139584);Ryukyu Islands , Okinawa,alive, 23 m (1 pr, ZMA Moll.142431).— CHINA: Hong Kong, just S of Wong Mau Chau (S Gau Island), 22°27' N 114°24'E, dead, 10 m (1 v, C.336899); Hong Kong, SE of Ping Chau Island, Mirs Bay (Tai Pang Wang), E side, 22°33'N 114°24'E, dead, 8 m (9 v, C.336900). — VIETNAM: off Nha Trang, Hon Mieu, alive, 4–5 m (1 pr, ZMA Moll.139640).— PHILIPPINE ISLANDS : Bohol,Pamilacan Island, 9°30'N 123°55'E, alive, 1–3 m (2 pr,C.161932); Sulu Archipelago, Basilan Island,off Zamboanga,alive, 1–4 m (13 pr, ZMA Moll.142428).— MARSHALL ISLANDS :KwajaleinAtoll,Carlson Islet,outside lagoon,alive, 12 m (2 pr, ZMA Moll.142360);KwajaleinAtoll,Shell Islet, inside lagoon, alive, 6 m (1 pr, ZMA Moll.142361); Kwajalein Atoll, inside lagoon, alive, 15 m (1 pr, ZMA Moll.142377); Kwajalein Atoll, oceanside of west reef, alive, 15 m (1 pr, ZMA Moll.144038).— INDONESIA: Irian Jaya, Biak Island,alive,intertidal on exposed reef (1 pr, ZMA Moll.143721); Ambon, Hitu, Kaitetu (near Hila), alive, intertidal (1 pr, ZMA Moll.143752). SRI LANKA:Hikkaduwa,dead,beach (12 v, ZMA Moll.011963).— THAILAND: Phuket Island, Raya Ya Islet,alive, 20–40 m (2 pr, ZMA Moll.143691). COCOS (KEELING) ISLAND: W of Direction Island, dead, 15–20 m (1 pr + 1 v, WAM 500); Turk Reef, dead, 9–35 m (1 v, WAM 501; 1 v, WAM 502); Flat SE Horsburgh Island, alive, 5 m (1 pr, WAM 503); SE Horsburgh Island, dead, 15–25 m (1 v, WAM 504); Horsburgh Island, dead, to 40 m (1 pr, WAM 505); NW side, dead, 15–25 m (2 v, WAM 506);N side,dead(1 v, WAM 507). CHRISTMAS ISLAND (Indian Ocean): 10°30'S 105°40' E,dead (3 pr,C.147395);Flying Fish Cove, 10°30'S 105°40'E, dead, 5–25 m (2 pr, ZMA Moll.146221); Flying Fish Cove, Nissa Maru, 10°30'S 105°40'E, dead, 15 m (1 pr, ZMA Moll.143651);E side of North West Point,dead, 0–30 m (3 pr + 1 fragm., WAM 508); Flying Fish Cove, dead (9 v, WAM 509); W coast, just N of Egeria Point, dead, 3–25 m (1 pr + 1 v, WAM 510); off Dolly Beach, dead, 0–25 m (1 pr + 1 v, WAM 511); Greta Beach, dead (1 pr, WAM 512); Flying Fish Cove, opp. small boat ramp, dead, 0–25 m (2 pr + 7 v, WAM 513). — PAPUA NEW GUINEA: Madang,Sek Harbour,sheltered N side, 5°05'S 145°50'E,alive(1 pr,C.344012); Madang, Kranket Island,inlet at N end, 5°11'S 145°51'E,dead,intertidal (1 pr,C.332561); Madang Harbour,Tab Island,S side, 5°11'S 145°50' E,dead, 11 m (1 pr,C.332562); Port Moresby, Horeshoe Reef, 9°28'S 147°10'E,dead, 25 m (1 v,C.332560); Port Moresby,Manudaba (Local)Island,off W end, 9°31'S 147°10'E,dead, 18–22 m (1 v,C.336901); Port Moresby, Quayles Reef, alive, 6 m (2 pr, ZMA Moll.141102). — SOLOMON ISLANDS : Guadalcanal, Honiara, W of Point Cruz, 9°25'S 159°56'E,dead,beach (1 v, C.332559); Guadalcanal, Bonegi, alive, 9 m (1 pr, ZMA Moll.142372); Russell Islands , Mbanika Islet,Linggatu Cove, alive, 6–9 m (3 pr, ZMA Moll.142373); Kira Kira,San Cristobal, 10°27'S 161°53'E,dead, 15–24 m (1 pr + 1 v, WAM 515).CORAL SEA:Portlock Reef, 9°43.48'S 144°49.24'E, alive, 8 m (2 pr, C.303898); Osprey Reef, SE end, 13°59'S 146°40'E, dead, 8–15 m (1 v,C.332558); Saumarez Reef, 21°49'S 153°40'E, alive, 6 m (1 pr, C.344013). — NEW CALEDONIA: Nouméa, outside main reef, alive, 15 m (1 pr, ZMA Moll.142365); Pouébo, alive, 20 m (1 pr, ZMA Moll.142367).

Description. Shell up to 40 mm high, most specimens under 30 mm; subcircular to prosocline, inequivalve, inequilateral, left and right valves almost equally inflated, auricles highly unequal in shape and size, umbonal angle c. 80–85°; colour highly variable, cream, yellow, orange, red, purple, brown to almost black; uniform or a variable pattern of dots and/ or streaks. Interior glossy, coloured as exterior.

Both valves sculptured with c. 40–50 unevenly spaced, minutely sqamose, rounded radial riblets of variable prominence. Intercalated microscopic antimarginal scratches laterally, more prominent on anterior end of right valve. Anterior auricles much larger than posterior, with delicate scaly riblets (c. 10 on left valve, c. 5 coarser ones on right valve), anterior auricle of right valve somewhat declined dorsally. Byssal notch deep, byssal fasciole broad. Functional ctenolium well-developed, with c. 6–8 teeth.

Dimensions. Illustrated specimen: QLD, GBR, off Great Palm Island (AM C.303770): rv: H 32.8, L 29.3 mm; lv: H 32.6, L 27.8 mm; D 9.4 mm.

Habitat. Living in the littoral zone, byssally attached to undersides of coral slabs, amongst rubble and live coral on sandy bottoms.

Distribution. Tropical Indo-West to central Pacific, from southern Japan southwards to northern Australia, westwards into the Indian Ocean to Sri Lanka, and eastwards across the Pacific to the Phoenix Islands (as Chlamys sp. cf. C. irregularis ; Waller, 1972: 239; Raines & Poppe, 2006: 198); Japan to Indonesia, 2–150 m (Huber, 2010: 207); Philippines, 4–24 m (Dijkstra, 2013: 65); Indonesia, 10–25 m, dead (Dijkstra & Moolenbeek, 2008: 19); Papua New Guinea, 3–25 m (as Laevichlamys irregularis ( Sowerby II, 1842) ; Dijkstra, 1998a: 32–33). Maximum depth range of live-taken specimens is from the intertidal zone to 40 m. Present specimens from Australia alive at 1– 17 m.

Remarks. The present specimens from tropical Australia are similar to the type material, although slightly more subcircular, but intermediate variations are commonly observed (AM, HD, MNHN). Other characters are identical.

Figure 68. Distribution of Laevichlamys cuneata (Reeve) .

Waller (1972a: 238) listed a scallop, Chlamys sp. cf. irregularis (Sowerby) , from “Cocos-Keeling, Caroline, Marshall, Gilbert, and Phoenix Islands ”, which is conspecific with the present species, with identical characters to the type material of Laevichlamys cuneata .

The Hawaiian morph, Chlamys cookei Dall, Bartsch & Rehder, 1938 , differs slightly from Laevichlamys cuneata in having a more circular shape ( L. cuneata is more obliquely oblong), by its finer radial sculpture, and by its brighter coloration (dark colours as in typical specimens from the western Pacific are not observed). It is possible that Chlamys midwayensis Habe & Okutani, 1968 from Midway Island (in the Hawaiian chain) is conspecific with the Hawaiian morph, although it has somewhat coarser radial sculpture and probably occurs in deeper waters (400–460 m).