Annachlamys iredalei ( Powell, 1958 )

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 : 213-214

Annachlamys iredalei ( Powell, 1958)

Figs 51C,F, 53A–B,D

Aequipecten (Corymbichlamys) iredalei Powell, 1958: 67 , pl. 11, figs 1–2, text-fig. 2.

Annachlamys iredalei (Powell) .–Dijkstra, (1983–1994) 1989: 19, figs; Dijkstra, 1990a: 8, 10, figs; Dijkstra et al., 1989: 24; Lamprell & Whitehead, 1992: [26], pl. 11, fig. 64; Dijkstra & Marshall, 1997: 97, pl. 10, figs 1–7; Brook & Marshall, 1998: 212; Raines & Poppe, 2006: 92, 93, lower fig; pl. 28, figs 5–6; Dijkstra & Marshall, 2008: 47, figs 37G, I, 39; Spencer et al., 2009: 198.

Corymbichlamys iredalei (Powell) .– Rombouts, 1991: 36, pl. 13, fig. 6.

Type data. Holotype (pr) ZMUC BIV-37. Type Locality: Kermadec Islands , off Raoul Island, 29°13.5'S 177°57'W, alive, 58–60 m ( Galathea stn 675).

Comments on type data. Powell (1958: 68) also listed a left and right valve collected at Galathea stn 674, Kermadec Islands , off Raoul Island, 29°15'S 177°57'W, 75–85 m and valves from Norfolk Island, 0.5 miles east of Philip Island, 33 fathoms [60 m] deposited in NIWA, Wellington.According to the ICZN (1999: art. 72.4.1 and 72.4.5) these are all paratypes. In the collection of SAM (D14593) there is also a paratype (lv) from Galathea stn 674 (“Powell. May, 1959. Exchange” on label), which is not the left valve mentioned by Powell (measurements differ). More paratypes were distributed to other institutions (e.g., AMNH105519, 5 v; Boyko & Sage, 1996: 11). Boyko & Sage (1996: 11) also recorded paratypes at Florida Museum of Natural History, FMNH118997.

Extralimital material examined. NORFOLK ISLAND: 29°02'S 167°57' E, dead (1 v, C.300229) . — NEW ZEALAND: Kermadec Islands , off Raoul Island, 29°15'S 177°52'E, dead (2 v, C.081779); a further 8 lots were listed by Dijkstra & Marshall (2008: 47). TASMAN SEA: Lord Howe Island, 31°33'S 159°05'E, dead (1 v,C.059653); Lord Howe Rise, 30°25.5' S 159°05.6'E,dead, 49–51 m (10 v,C.123839); Lord Howe Rise, 31°34.9'S 159°00.3'E, alive, 73 m (5 v, C.123974); Lord Howe Rise, 31°37.1'S 159°13'E, dead, 51–55 m (many v, C.123844); Lord Howe Rise, 31°38.2'S 159°03.6'E,alive, 44 m (1 pr + many v,C.123718);off Ball’s Pyramid, 31°45' S 159°15'E, dead, 91–183 m (1 v,C.300228);off Lord Howe Island , 31°45.73'S 159°20.93'E, 565–960 m, NORFANZ stn 66, dead (7 lv, NMNZ M171160 ) .

Description. Shell up to c. 80 mm high, solid, subcircular, weakly inflated, almost equally convex (right valve slightly more convex than left), somewhat wider than high, inequivalve, almost equilateral (posterior suture longer than anterior); auricles rather small, unequal in size and shape; umbonal angle c. 115°; resilial, dorsal and intemediate teeth weak; left valve brightly coloured externally with salmonpink patterned with paler dots and streaks, right valve paler than left valve, yellowish, interior yellowish to pink.

Both valves sculptured with 15–18 evenly spaced radial plicae, becoming narrower and weaker at anterior and posterior ends of disc than in centre, with each interspace somewhat narrower than one plica; 3–5 secondary radial riblets developing on plicae and in interspaces late in ontogeny. Commarginal lamellae on plicae and interspaces (subdivided into imbricate scales), more prominent on right valve than on left. Auricles with 6–12 unevenly spaced radial riblets covered with commarginal lamellae. Internal rib carinae prominent near ventral margin, weaker near muscle insertion. Hinge of left valve straight, of right valve somewhat raised, with scales along dorsal margin. Byssal notch shallow, byssal fasciole narrow or almost lacking, functional ctenolium with 3–5 teeth.

Dimensions. Illustrated specimens: off Lord Howe Island, 31°45.73'S 159°20.93'E, 565–960 m, NORFANZ stn 66, dead (7 faded lv, NMNZ M171160); largest: H 69.1, L 74.4 mm; medium-sized (interior illustrated in colour): H 63.3, L 68.4 mm; medium-sized (no secondary riblets): H 52.8, L 59.8 mm; small (with secondary riblets): H 48.0, L 52.1 mm.

Habitat. Living in the littoral to bathyal zones amongst rubble and coral sand.

Distribution. Coral Sea, New Caledonia, Lord Howe Island, Norfolk Island, and Kermadec Islands , 15–183 m, alive at 15–70 m (Dijkstra & Marshall, 1997: 97; 2008: 47). Present material alive at 44– 73 m. Maximum living depth range is now extended to 15– 73 m. Annachlamys iredalei is not recorded from the east coast of Australia.

Remarks. For comparison with Annachlamys flabellata ( Lamarck, 1819) and A. reevei (A.Adams in Adams & Reeve, 1850) see Dijkstra & Marshall (1997: 97).

Figure 52. Distribution of Annachlamys kuhnholtzi (Bernardi) (circles) and A. reevei (A. Adams) (stars).