Annachlamys reevei (A. Adams & Reeve, 1850)

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 : 217-218

Annachlamys reevei (A. Adams in Adams & Reeve, 1850)

Figs 52, 53E,G, 54C,F

Pecten reevei A.Adams in Adams & Reeve, 1850: 73, pl. 21, figs 10a–b; Reeve, 1853: sp. 91, pl. 23, fig. 91; Küster & Kobelt, 1888: 208, pl. 56, figs 3–4.

Pecten (Aequipecten) reevei A. Adams in Adams & Reeve.– Dautzenberg & Bavay, 1912: 18, pl. 27, figs 3–4.

Annachlamys reevei (A. Adams in Adams & Reeve).– Kira, 1962: 211, pl. 72, fig. 7; Lan, 1979: 103, pl. 45, figs 105–107; Abbott & Dance, 1982: 306, fig.; Springsteen & Leobrera, 1986: 329, pl. 93, fig. 18; Okutani et al., 1989: 63, fig. 43; Dijkstra, 1991: 43; Higo et al., 1999: 445; Hayami, 2000: 905, pl. 450, fig. 37; Higo et al., 2001: 157, fig. B469 (syntype); Wang, 2002: 200, fig. 84; Raines & Poppe, 2006: 94, 95, lower figs; pl. 29, figs 1–7; Xu & Zhang, 2008: 85, fig. 240; Raines, 2010: 598, pl. 990, fig. 1.

Chlamys (Annachlamys) reevei (A. Adams in Adams & Reeve).– Rombouts, 1991: 22, pl. 9, fig. 8.

Type data. Lectotype (pr: H 53 mm, W 58 mm) NHMUK 1950.11 .14.58, figured by Adams & Reeve (1850: pl. 21 figs 10a–b), Reeve (1853: pl. 23 fig. 91), and Higo et al. (2001: fig. B469), herein designated. Two articulated paralectotypes (adult and juvenile) NHMUK 1950.11.14.59–60, not figured. Type locality: “ China Sea” [ South China Sea].

Comments on type data. In the type lot is another articulated specimen (largest) with the registered number NHMUK 74.12.11.375 from the “ China Sea” (ex Mrs T. Lombe Taylor), which possibly also belongs to the type series.

Additional material examined. — AUSTRALIA: QUEENSLAND: Gulf of Carpentaria,alive, 36 m (2 pr, ZMA Moll. 142798). WESTERNAUSTRALIA: Ashmore Reef, NE corner, 12°15'S 123°07' E, dead, 20–25 m (1 v, WAM); Ningaloo Marine Park, off Osprey Reef, 22°10.156'– 22°10.327'S 113°50.282'– 113°50.228'E, 58.6– 57.8 m, epibenthic sled, M. P. Salotti on AIMS RV Cape Ferguson, 01 May 2006 (2 v, WAM S64890 ); Ningaloo Marine Park,off Cloates Reef, 22°29.298'– 22°20.126' S 113°40.020'– 113°40.023' E, 40.0–44.0 m, epibenthic sled, J. Colquhoun on AIMS RV Cape Ferguson, 16 May 2006 (1 v, WAM S64891 ) .— JAPAN: Okinawa,off Bolo Point , alive, 50 m (1 pr, ZMA Moll. 144330) . TAIWAN: off southern Taiwan , alive, 46 m (1 pr, ZMA Moll. 139581) . — PHILIPPINE ISLANDS : Siasi, off Laminusa Island , alive, 45–56 m (2 pr, ZMA Moll. 142797) .

Description. Shell up to c. 60 mm high, solid, weakly inflated, right valve slightly more convex than left, subcircular (somewhat wider than high), inequivalve, almost equilateral (posterior suture longer than anterior); auricles rather small, almost equal in size; umbonal angle 115–120°; left valve brightly coloured with red, yellow, pink, purple or orange maculations and streaks on a whitish or cream background, right valve less maculated, paler; reddish internally.

Both valves sculptured with 16–18 evenly spaced radial plicae (becoming smaller and weaker at anterior and posterior ends of disc than in centre), plicae broader than interspaces. Delicate, closely spaced commarginal lamellae in early growth stage, more prominent and more widely spaced in late ontogeny, subdivided by a secondary riblet on crest of plicae of some specimens. Auricles with 4–6 evenly spaced radial riblets covered with commarginal lamellae. Internal rib carinae prominent near ventral margin, weaker near muscle insertion. Dorsal margin of left valve straight, somewhat inclined in right valve. Hinge teeth prominent. Byssal notch shallow, byssal fasciole lacking, functional ctenolium with 3–5 teeth in juvenile stage, lacking in adult.

Dimensions. Illustrated specimens: WA, Ningaloo Marine Park, off Osprey Reef, 58.6– 57.8 m ( WAM S64890 ), rv only: H 33.2, L 36.5 mm; WA, Ningaloo Marine Park, off Cloates Reef, 40–44 m ( WAM S64891 ), lv only: H 41.3, L 47.3 mm .

Habitat. Living free in adult stage, in the littoral zone and on the continental shelf, amongst rubble on soft sediment (generally sand).

Distribution. Sea of Enshunada and Izu Islands ( Japan) , southwards to tropical West Pacific, 10–50 m (Hayami, 2000: 905); Sulu Sea, Philippines, 5–10 m (Springsteen & Leobrera, 1986: 329; Raines, 2010: 598; Dijkstra, 2013: 53); Indonesia, 65–75 m, dead (Dijkstra, 1991: 43). Maximum depth range 10–150 m ( Okutani et al., 1989: 63). Distribution herein extended to northern Australia. Present specimens from Australia alive at 36 m.

Remarks. Annachlamys reevei is a new record forAustralia. Specimens from the Gulf of Carpentaria and Ashmore Reef are indistinguishable from the type material.

Annachlamys reevei closely resembes A. iredalei , but differs in several characters, as shown in Table 4.