Annachlamys iredalei (Powell, 1958)
POWELL, A. W. B. 1958. Molluscs of the Kermadec Islands Pt. I. Records of the Auckland Institute and Museum, 5 (1-2): 65-85, pls. 9-11. [p. 68, pl. 11. figs. 1, 2; text fig. A.2]
1958 Aequipecten (Corymbichlamys) iredalei Powell, 1958
A. W. B. Powell, 1958, plate 11.
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«Shell of medium size and rather feeble inflation, moderately solid, length slightly greater than height subequivalve, right valve of slightly the greater convexity, subequilatera, the shell produced a little more posteriorly. Suborbicular except for well developed ears and a flat to slightly concave outline to the anterodorsal and postero-dorsal margins, which show a diverergence of from about 102° for medium sized shells ro about 114° for the Iargest example.
Radials, strong broad corrugations with deeply channelled interspaces which vary between half and equal width of the radials. Seventeen radials, fourteen of them promirent and wide spaced, three marginal ones, crowded, one antero-dorsal and two postero-dorsal. Ears large, subequal. Surface sculpture very elaborate. Each primary rib bears seven narrow riblets, centre one most prominent, the whole crossed by dense concavely arcuate lamellae, continuous but produced into crisp scales where they cross the riblets; best developed at the flanks. Intercostal spaces bearing three radial series of closely packed prominent imbricating scales. Anterior ear bearing six radials in the right valve, which are rendered densely squamose by concentric lamellae. Posterior ear with eight to twelve similarly sculptured radials. Byssal sinus narrow, or moderate depth; ctenolium short with only four small teeth. Hinge line straight with a deep narrowly triangulate resilial pit and a pair of cardinal crura on each side of the resilifier. The outermost crura are long and parallel to the dorsal margin, in the left valve but slightly divergent to it in the right valve. A second still more divergent but very short pair of crura coalesce with the upper extremities of the provinculum. Both pairs of crura bear distinct crowded vertical taxodont-like grooves which have almost the magnitude of interlooking teeth. Colour of right valve pale orange-buff, broadly and irregularly blotched with pale orange-brown, left valve similarly patterned but in bright salmon-pink. Interior of right valve yellowish-buff turning to deep orange-brown at the dorsal edges, hinge plate and ears; left valve similarly coloured at the margins but diffused with deep carmine-pink over the central area, except where lightened with callus. Large examples have the interior more uniformly salmon-pink. Height, 33 mm.; length, 35 mm.; thickness (2 valves) 10.7 mm. (Holotype).
Height, 8 mm.; lenght, (65 mm.; thickness (Ieft valve) 11.0 (St. 674). Height, 75 mm.; length, 84.5 mill.; thickness (right valve) 13.5 mm. (St. 674). Locality; Galathea St. 675, 29° 13.5' S.; 177° 57' W., off Raoul Island Kermadecs, 58-60 metres, 3:3:1952 (Holotype, one live shell); St. 674, 29° 15' S.; 177° 57' W., off Raoul Island, 75-85 metres (gravel bottom; many dead shells); ½ mile east of Philip Island, Norfolk Island, 33 fathoms (N.Z. Oceanographic Institute, Wellington) (valves). I am indebted to Ir. To Mr Tom Iredale of Sydney for the suggested relationship of this species with Corymbichlamys corymbiatus Hedley. Iredale's genus however, is quite similar to Aequipecten Fischer, 1887 based upon the European opercularis Linnaeus, it also shows vertical crural striations but they do not persist in the adults. Only the elaborate sculptural development is wanting in opercularis althouh the lamellar arrangement is there in incipient form.
The relationship of the Kermadec shell is probably better expressed by retaining Corymbichlamys as a subgenus of Aequipecten for deeply corrugated species exhibiting the complex sculptural detail described above, plus a marked development of the crural striations throughout aiI stage of growth. An evident related species is the Hawaiian deep-water shell named Cryptopecten alli, gen. and sp,. nov. by Dall, Bartsch and Rehder, 1938. This has even more elaborate sculpture than Corymbichlamys with the rib lamellae fused into series of hollow blisters. The hinge bears distinct cardinal crura also. I have not seen the Hawaiian shell so should Hedley's Chlamys corymbiatus and Dall, Bartsch and Rehder's species prove to be congeneric then Cryptopecten will replace Corymbichlamys for the Queensland and the Kermadec species.» ARTHUR WILLIAM BADEN POWELL, 1958
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«TYPE LOC.: Off Raoul Island (29°11.5'S,177°57'W): 58-60m . 3.111.1952.
TYPE MATERIAL: Holotype preserved at the Zoological Museum of Copenhagen. Paratypes kept at the ZMC and the N.Z. Oceanographic Institute of Wellington. GEOGRAPHIC DISTRIBUTION: At present only recorded from the Kermadec Islands, New Caledonia and the Coral Sea. N.C. BATHYMETIIC RANGE: Approximately from 30 to 80 m. N.C. ECOLOGICAL RANGE: Between coral rubble on a sandy bottom. REMARKS: Powell (1958: 68-69) placed this species on advice of lredale in the subgenus Corymbichlamys lredale (1939: 367) of Aequipecten. Representatives of the genus Aquipecten are more or less restricted to the Atlandc region, whereas Corymbichlamys is now treated as a junior synonym ol Cryptopecten Dall, Bartsch and Rehder (1938: 93), and distributed throughout the Indo-Pacific region. ln my opinion, this species is more belonging to the genus Annachlamys lredale (1939: 358), because several conchological featuresa are identical with representatives of this genus. A very close related species is Annachlamys reevei (A. Adams in A. Adams and Reeve, 1850) from the western Pacific. The Iargest known specimen from New Caledonia of A. iredalei measures 75 mm in height, and 86 mm in width and is live collected outside of the mainreef off Noumea.» DIJKSTRA, H. H. 1989. Les Pectinidae de Nouvelle-Calédonie/The Pectinidae of New Caledonia. 20. Annachlamys iredalei (Powell, 1958). Rossiniana, 42: 19-20. [p. 20]
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Annachlarnys Iredalei (Powell, 1958); H. H. Dijkstra, The Pectinidae of New Caledonia. 20. Annachlamys iredalei (Powell, 1958), 1989, page 19.
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