Cyclopecten horridus Dijkstra, 1995

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 : 149-150

publication ID	https://doi.org/ 10.3853/j.2201-4349.70.2018.1670
publication LSID	lsid:zoobank.org:pub:8084C----
persistent identifier	https://treatment.plazi.org/id/039A87AD-F83D-3661-FC5C-2A03FD6DF833
treatment provided by	Felipe
scientific name	Cyclopecten horridus Dijkstra, 1995
status

Treatment

Cyclopecten horridus Dijkstra, 1995 View in CoL

Figs 15E,G,J, 16

Cyclopecten horridus Dijkstra, 1995b: 41 , figs 63–64, 98; Dijkstra & Marshall, 1997: 87, pl. 6, figs 1–6; Dijkstra & Marshall, 2008: 16, figs 12E–H, 13; Spencer at al. 2009: 198; Dijkstra & Maestrati, 2015: 617, figs 6H–I.

Type data. Holotype (pr) MNHN Moll 21163, 7 paratypes (v) (5 MNHN Moll 21164–21166, 2 ZMA Moll.395020). Type locality: Loyalty Islands , 20°29'S 166°43'E, alive, 600 m (MUSORSTOM 6 stn DW 420). GoogleMaps

Additional material examined. — AUSTRALIA: QUEENSLAND: Capricorn Channel , 23°11.5'S 152°14.5'E,alive, 188 m (2 pr,C.165232) GoogleMaps . CORAL SEA: Brittannia Guyot , 28°17.04'S 155°36.46' E, alive, 425 m, 5 pr, alive (5 pr, C.165416; 2 pr, C.165417) GoogleMaps . TASMAN SEA: Derwent Hunter Seamount , 30°48.18'S 156°13.27' E, alive, 288 m (1 pr, C.165245) GoogleMaps .

Description. Shell up to c. 6 mm high, almost circular, left valve more convex than right, inequivalve, equilateral, auricles almost equal in size, umbonal angle c. 125°, opaque whitish.

Left valve sculptured throughout with commarginal lamellae, present also on auricles, and closely spaced in early growth stage, enlarging ventrally. Erect hollow spines on lamellae. Interstitial microsculpture of antimarginal scratches in late growth stage.

Right valve with closely spaced, fine commarginal lamellae, more prominent near ventral margin. Anterior auricle with 3 radial riblets crossed by commarginal lamellae. Dorsal margin straight. Byssal notch moderately deep, byssal fasciole narrow.

Habitat. Living in the bathyal zone on soft sediment (sand and mud) amongst rubble.

Figure 17. A–C, E, H, Cyclopecten kapalae Dijkstra , paratypes, separate valves, AM C.165060, off Sydney, NSW, FRV Kapala Stn K 80-20-08, 33°31'S – 33°33'S 152°08'E – 152°07'E, 907–914 m; lv exterior (A), rv exterior (B), rv anterior auricle exterior (C), lv anterior auricle exterior (E), lv interior (H). D, F, G, I, Cyclopecten powelli Dell , separate valves, WAM S77658 View Materials , RV Southern Surveyor stn SS1005/043, off Albany, WA, 35°25'03"– 35°25'58"S 118°22'26"– 118°21'58"E, 1019–1031 m; lv anterior auricle exterior (D), lv exterior (F), rv exterior (G), rv anterior auricle exterior (I). Scale bars represent 3 mm (A, B, F–H), 0.5 mm (C–E, I).

Distribution. New Caledonia, 435–735 m, dead; Loyalty Islands , 600 m (Dijkstra, 1995b); Kermadec Islands , 350–538 m (Dijkstra & Marshall, 1997, 2008). Now also from Australia (Queensland), the Coral Sea and the Tasman Sea. Recently also recorded from off Transkei, South Africa, 150–200 m, dead (Dijkstra & Maestrati, 2015). Maximum depth range of live-taken specimens is 188– 600 m.

Remarks. The present material from Australia is similar to the type specimens from the Loyalty Islands , although the sculpture of the left valve is somewhat more prominent.

Cyclopecten horridus is a new record for Australia.