Anguipecten superbus (G. B. Sowerby II, 1842 )

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 : 179-181

Anguipecten superbus (G. B. Sowerby II, 1842)

Figs 30, 32A,C, 34A,C

Pecten superbus G. B. Sowerby II, 1842: 62 , pl. 12, fig. 11; Reeve, 1853: sp. 107, pl. 26, fig. 107.

Anguipecten superbus (Sowerby) .– Koyama et al., 1981: 69, pl. 1, fig. 3; Abbott & Dance, 1982: 312, fig.; Dijkstra, (1983–1989) 1984: 8, figs; Springsteen & Leobrera, 1986, 328, pl. 93, fig. 8; Bernard et al., 1993: 51 [in part]; Dijkstra, 1998a: 15, pl. 2, figs 2-3; Hayami, 2000: 903, pl. 449, fig. 31; Dijkstra, 2002: 140, fig. 9; Wang,

Figure 32. A, C, Anguipecten superbus (G. B. Sowerby II) , pair, HM, N side of Ashmore Reef, WA, 12°17'S 123°02'E, 34 m; lv exterior (A), rv exterior (C). B, F, H, Bractechlamys vexillum (Reeve) ; (B) rv of pair, holotype of Bractechlamys evecta Iredale, AM C. 075283, Great Barrier Reef Exped. stn 14, 0.5 ml SE of Lizard Island, GBR, 19 fathoms [35 m]; (F, H) pair, AM C.119718, 0.8 km N of Eagle Isle, GBR, QLD, 18 m; rv exteriors (B, H), lv exterior (F). D, E, Bractechlamys oweni (Gregorio) , pair, HM, off Hibernia Reef, WA, 30–35 m; lv exterior (D), rv exterior (E). G, I, Decatopecten strangei (Reeve) , pair,AM C.097573, Dundowran Beach, Hervey Bay, QLD; lv exterior (G), rv exterior (I). Scale bars represent 20 mm (A–C, F–I), 10 mm (D, E).

2002: 206, fig. 87; Raines & Poppe, 2006: 90–91, pl. 25, figs 1–5; Xu & Zhang, 2008: 85, fig. 235; Dijkstra & Maestrati, 2010: 352, fig. 5D; Huber, 2010: 198; Raines, 2010: 596, pl. 989, figs 4–6; Dijkstra, 2013: 34, pl. 7, figs 3a–d, pl. 9, figs 2a–b.

Decadopecten (Anguipecten) superbus (Sowerby) .– Rombouts, 1991: 38, pl. 14, figs 2–2a.

Type data. Lectotype (largest pr) NHMUK 1950.11.14.78, herein designated; possible paralectotype (pr) NHMUK 1950.11 .14.79. Type locality: Not mentioned.

Comments on type data. The type lot consists of two selected articulated specimens with the registered numbers NHMUK 1950.11.14.78–79. However, Sowerby (1842, p. 62) recorded in his original description: “We have only seen one specimen of this magnificent shell which is in the collection of Mr. Cuming. ” The designated lectotype is closest to the measurements mentioned by Sowerby : “Long. 2.40; lat. 0.65; alt. 2.60 poll.” [= width 60.89 mm, thickness 16.49 mm, height 65.96 mm] and to Reeve’s (1853: pl. 26, fig. 107) figure. Although no type locality was indicated by Sowerby, “ Amboina ” [= Ambon, Indonesia] is written on labels of the type lot .

Additional material examined. — AUSTRALIA: WESTERN AUSTRALIA: Scott Reef, N entrance, approx. 14°0'S 121°45'E, dead, 42 m (1 v, WAM); Scott Reef, NE corner, approx. 14°0'S 121°45'E, dead, 28–30 m (2 v, WAM); Scott Reef,SE corner, approx. 14°0' S 121°45' E, dead, 32 m (1 v, WAM); Seringapatam Reef, NE corner, approx. 13°40'S 121°59' E, dead, 28 m (1 pr, WAM); Ashmore Reef, N side, 12°17'S 123°02'E, alive, 34 m (1 pr, HM) . — JAPAN: Okinawa, Seragaki , alive, 40–55 m (5 pr, ZMA Moll. 142853) . — PHILIPPINE ISLANDS : Cebu, alive, 40 m (1 pr, WAM) . — MALAYSIA: Malacca Strait , alive, 66 m (1 pr, ZMA Moll. 142854) . — PAPUA NEW GUINEA: Hansa Bay, Laing Island , alive (1 pr, ZMA Moll. 145641) . — SOLOMON ISLANDS : Guadalcanal, W Honoraria, alive, 30–35 m (2 pr, ZMA Moll. 144005); Russell Group, Mbanika Island, Yandina , alive, 55 m (1 pr, ZMA Moll. 142852) .— MARSHALL ISLANDS : KwajaleinAtoll , Kwajalein Island ,oceanside of reef, dead, 30 m (1 v, ZMA Moll. 144023) .

Description. Shell up to c. 70 mm high, most specimens smaller; solid, somewhat triangularly oblong, weakly inflated, posterior margin longer than anterior, left and right valves almost equally convex, slightly inequivalve and somewhat inequilateral, auricles very short and almost equal in size, umbonal angle 85–90°; cream maculated with dots and streaks (cream, orange, red or brown), right valve paler and more uniform than left.

Both valves sculptured with 20–25 evenly spaced radial costae, with only a few secondary radial riblets on anterior and posterior ends. Microsculpture of very closely spaced commarginal lamellae. Auricles almost smooth, anterior auricle of right valve weakly sculptured with radial riblets. Dorsal margin straight. Inner surface plicated, with weak internal rib carinae near margin. Adductor scar insertion prominent. Resilifer narrowly triangular, with sides erect. Resilial teeth weak, intermediate teeth well-developed. Byssal notch shallow in juveniles, almost absent in adults, byssal fasciole absent. Weak functional ctenolium with 1–3 teeth in juveniles, absent from adults.

Dimensions. Illustrated specimen: WA, S side Hibernia Reef, N of Ashmore Reef, 30–35 m (HM): H 61.5, L 56.4 mm.

Habitat. Living in the littoral zone and on the continental shelf, under coral slabs or boulders or amongst coral rubble on soft sediment (sand).

Distribution. Indo-West Pacific, from southern Japan southwards to northern Australia, and eastwards to the Marshall and Solomon Islands ; Amami Islands , southwards to tropical West Pacific, 10–30 m (Hayami, 2000: 903); Philippines, 10-30 m (alive), 80-120 m (dead) ( Raines, 2010: 596; Dijkstra, 2013: 34), Camotes Sea, “deep water” (Springsteen & Leobrera, 1986: 328), Calituban Island, Aliguay Island, Olango Island, 10–30 m ( Raines, 2010); East and South China Sea, Borneo, Indian Ocean, intertidal– 50 m (Bernard et al., 1993: 51, in part); Japan and SW Pacific, 10–80 m (Abbott & Dance, 1982: 312); Japan, Okinawa to Australia, 10-130 m (Huber, 2010: 198); Papua New Guinea ( Rombouts, 1991: 38);Austral Islands , 90–120 m (Dijkstra & Maestrati, 2010: 352); South Africa, Zululand, 100 m, dead (Dijkstra & Kilburn, 2001: 273). Maximum depth range is intertidal to 165 m (HHD, unpublished data).

Remarks. Anguipecten superbus is a new record for Australia, so far only collected alive from coral reefs (southern Timor Sea) outside the continental waters of northern Western Australia. Huber (2010: 198) also recorded specimens from “ Australia ”, but he did not specify the locality. Specimens from that region differ slightly from the lectotype in having one or two more radial costae, but the other characters are identical.