Delectopecten vancouverensis vancouverensis (Whiteaves, 1893)
WHITEAVES, J. F. 1893. Notes on some marine invertebrata from the coast of British Columbia. Ottawa Naturalist, 7: 133-137, pl. 1. [p. 133, pl. 1, figs. 1, 1a]
1893 Pecten (Pseudamusium) [sic] vancouverensis Whiteaves, 1893
1897 Pecten randolphi Dall, 1897
1906 Pecten (Pseudamusium) [sic] randolphi var. tillamookensis Arnold, 1906
1913 Pecten (Pseudamusium) [sic] arces Dall, 1913
1915 Pecten whiteavesi Orcutt, 1915
1978 Cyclopecten argenteus Bernard, 1978
1897 Pecten randolphi Dall, 1897
1906 Pecten (Pseudamusium) [sic] randolphi var. tillamookensis Arnold, 1906
1913 Pecten (Pseudamusium) [sic] arces Dall, 1913
1915 Pecten whiteavesi Orcutt, 1915
1978 Cyclopecten argenteus Bernard, 1978
J. F. Whiteaves, 1893, plate 1.
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«Shell small, equivalved, compressed lenticular, both valves being equally convex, ovately subcircular in outline apart from the ears and rather oblique; valves extremely thin and fragile, translucent and almost transparent, pale horn colour with a slightly yellowish hue. Beaks placed a little behind the midlength; hinge line straight and very long; ears unequal in size, the posterior pair, which are much smaller than the anterior, alike, indistinctly defined and merging gradually and imperceptibly into the general convexity and marginal contour of that side of each valve; anterior ears large, subtriangular, prolonged laterally and longer than high, distinctly defined, that of the left valve somewhat convex in outline above and concave below, that of the right valve with a deep and acutely angular byssal sinus at its base.
Surface marked by densely crowded and exceedingly minute, irregular and rarely continuous, but on the whole radiating, simple or bifurcating raised lines, also by comparatively large, regularly disposed and distant squamose radii. In the centre of each valve the minute and non-squamose raised lines are essentially parallel to the larger squamose radii, but on the sides the former are disposed obliquely to the latter. The surface of the anterior ear of each valve is minutely cancellated with extremely minute raised lines, which are almost parallel to the hinge line, in addition to the coarser cross lines. The whole sculpture of the exterior of the test is far too minute to be clearly seen without the aid of a microscope or powerful simple lens, but under either of these a few faint concentric lines of growth are also visible. Dimensions of the only specimen that the writer has seen : height, from beaks to base, 7.50 mm.; maximum length, 7.75 mm.; greatest thickness through the closed valves, 2.25 mm. Forward Inlet, Quatsino Sound, Vancouver Island, in ten to twenty fathoms mud, Dr. G. M. Dawson, 18.85: one living 'Specimen. In the list of specimens collected by Dr. Dawson in that year, the little shell upon which the foregoing description is based, was erroneously identified with the Pecten Alaskensis of Dall. A subsequent study of its characters, has led to the conclusion that it is much more nearly related to Pecten vitreus, Chemnitz, and P. abyssorum, Loven, from both of which it can be readily recognized by its very peculiar sculpture. P. Alaskensis has opaque and much thicker valves and different surface markings. Its posterior auricles are distinctly defined and its anterior auricles very much smaller in proportion to the size of the shell, than those of P. Vancouverensis. The credit of first distinguishing between the species last named and P. Alaskensis is due to the Rev. G. W. Taylor, of Victoria, V.I., who informs the writer that he has two specimens in his collection dredged in about ten fathoms sand, Departure Hay, near Nanaimo, in 1888.» JOSEPH FREDERICK WHITEAVES, 1893
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«Delectopecten vancouverensis (Whiteaves, 1893). Vancouver scallop.
Pecten (Pseudamussium) vancouverensis Whiteaves 1893; Pecten randolphi Dall 1897; P. whiteavesi Orcutt 1915; Pecten (Pseudamusium) randolphi tillamookensis R. Arnold 1906; P. (Pseudamiusum) arces Dall 1913; P. (Pseudamusium) vancouverensis fernandoensis Hertlein 1925; Cyclopecten argenteus F. R. Bernard 1978. Type locality: Forward Inlet, Quatsino Sound, Vancouver Island, British Columbia, Canada. Distribution: Prince William Sound, Alaska, south to Islas San Benito and Isla Cedros, Baja California, and off Guaymas, Sonora, Mexico, and Kamchatka to northern Japan; 27–4100 m; common.» DRUMM, D. T., K. P. MASLENIKOV, R. V. SYOC, J. W. ORR, R. R. LAUTH, D. E. STEVENSON & T. W. PIETSCH. 2016. An annotated checklist of the marine macroinvertebrates of Alaska. NOAA Professional Paper NMFS, 19: 1-289. [p. 142]
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«Additional descriptive notes: Although not mentioned in Whiteaves' very thorough description, a ctenolium of 3 to 6 teeth is present, Many specimens have shallow concentric undulations of the umbonal portion of the disk. On some specimens the squamose sculpture is almost absent and the radii more prominent. Very young shells are frequently nearly smooth. Whiteaves' phrase, " ... pale horn color with a slightly yellowish hue." is misleading, for when specimens are washed they are devoid of color.
Remarks: The squarish angle of the posterior auricles and the longer hinge line distinguish this species from the related Cyclopecten randolphi and C. randolphi tillamookensis, the presence of sculpture on the disks also separating it from the former. Geographic range: Bering Sea to southern end of Lower California, Mexico, and north in the Gulf of California to San Ildefonso Island, 26° 33' 30" N. Previous records indicated San Diego, California, to be the southern limit, but the species occurred at Hancock stations in Dewey Channel and off the San Benito Islands, western Lower California, and off San Ildefonso Island in the Gulf. Geochronological range: Recent only. Bathymetric range: 10 to 210 fathoms (rarely less than 50). Ecological data: Usually on mud or sand bottoms, occasionally rock, shale or gravel; often attached to calcareous algae; often associated with brachiopods, crinoids, coralline or sponge.» GRAU, G. 1959. Pectinidae of the eastern Pacific. Allan Hancock Pacific Expeditions, 23: i-viii, 1-308, 57 pls. University of Southern California Press. Los Angeles, California. [p. 42]
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Cyclopecten (Delectopecten) vancouverensis (Whiteaves) 1893; G. Grau, 1959, Pectinidae of the eastern Pacific, plate 15.
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