Pecten albicans (Schröter, 1802)
SCHRÖTER, J. S. 1802. Neue Conchylienarten und Abänderungen, Anmerkungen, und Berichtigungen nach dem linnéischen System der XII Ausgabe. Archiv für Zoologie und Zootomie, 3 (1): 125-166. [p. 136]
1802 Ostrea albicans Schröter, 1802
1842 Pecten laqueatus Sowerby, 1842
1844 Pecten antonii Philippi, 1844
1842 Pecten laqueatus Sowerby, 1842
1844 Pecten antonii Philippi, 1844
Pecten laqueatus Sowerby; C. E, Lischke,1871, Japanische Meeres-Conchylien, Vol. II, plate 12.
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«1. Der meine Mantel
mit breiten flachen ribben
Ostrea albicans
Dieser Mantel, von dem ich nur die gewölbte Unterschale besitze, ist drey
ein viertel Z. laug, drey einen halben Z. breit, stark gewölbt und hat 12
Ribben. Diese Ribben sind stach, oder vielmehr breit und platt, und die sechs
gröβern haben am äussern Rande eine Breite von einem halben Zolle. Sie sind glatt,
und nur gegen das Licht gehalten siehet man einige senkrechte Streifen, die
aber gleichsam nur hindurch schimmern. Auch die Furchen zwischen ihnen sind glatt,
doch laufen über die Schale hin und wieder geschlängelte Queerstreifen, in
regelmäβigen Entfernungen. Diese siehet man auf den Ribben sowohl als in den
Furchen, sie können daher durch neue Schalenandsbe entstanden seyn. Die Ohren sind
von gleicher Größe, etwas gerunzelt, doch hat das eine einige kenntliche
schräge Streifen, und am Rüden der Schale eine tiefe gerunzelte Furche, was dem
andern Ohre alles stehlt. Der äussere Rand hat einen galtten Umriβ, von innen
aber siehet man Furchen, wo äussere lich Ribben sind, und Ribben, wo von
aussen Furchen sind. Das Schloβ hat ausser einigen schrägen Falten nichts
besonders. Die Schale ist von aussen und innen weiss; nur die Schlossfalten
sind inwendig braun, so wie man sonst hin und wieber noch eine zelue braune
Flecten und Striche inwendig gewahr wird. Von der Oberschale kann ich keine Nachricht geben.»
JOHAN SAMUEL SCHRÖTER, 1802
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«Pecten species are characterized for a broad geographic range distribution, inhabiting the coasts of four continents. However, in spite of the clear allopatric populations, very low mitochondrial genetic distances (ranging from 0.006 to 0.042) have been reported for members of this genus (Peña and Saavedra, 2012). The estimated genetic distance between P. albicans and P. maximus mitogenomes are in agreement with previous results by Peña and Saavedra (2012). Relatively low genetic distance (7%) and quite similar amino acid sequence identity (98.7%) found between the mitogenomes of P. albicans and P. maximus suggest a recent divergence event. Further studies using complete mitochondrial genome information from other Pecten species are needed to corroborate the recent diversification within this genus.»
MARÍN, A., T. FUJIMOTO & K. ARAI. 2015. The mitochondrial genomes of Pecten albicans and Pecten maximus (Bivalvia: Pectinidae) reveal a novel. Biochemical Systematics and Ecology, 61: 208-217, figs. 1-5. [p. 216]
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«In the Japanese Islands, Taiwan and Philippines there are five fossil and living species of the genus Pecten, that is, albicans, excavatus, naganumanus, puncticulatus and sinensis (Dickerson, 1922; Habe, 1977). Among them naganumanus is known from Pliocene to Pleistocene formations distributed from the Philippines to Japanese Islands, albicans ranges from the Pliocene to Recent, and the other species are living. Pecten (No to vola) sp. illustrated by Kanno (1960) from the Nenokami Sandstone, Saitama Prefecture, Central Japan has not been verified.
Comprehensive studies on the genus Pecten (s. s.) in New Zealand have been made by Fleming (I957). He subdivided the Pecten (s. s.) group into the Pecten benedictus and Pecten jacobaeus groups, which might have originated in the Mediterranean Region during the Miocene, and pointed out that these two groups migrated to New Zealand and Australia by different routes. Furthermore, he subdivided the Pecten (s. s.) group in the Western Pacific into Pecten excavatus Anton in the southern area and Pecten albicans (Schroter) in the northern area, and concluded that excavatus of the benedictus group migrated from the Mediterranean Region via Southeast Asia, and that Pecten aletes Hertlein of the jacobaeus group in the West Coast of North America extended its geographic range westwards to the Japanese Islands and gave rise to albicans. However, as Pecten albicans in the Japanese Islands is quite different morphologically from Pecten aletes described from the Pliocene of California, it is evident that the first appearance of Pecten naganumanus and P. albicans in the Pliocene formations of the Philippines, Taiwan and Japan are the result of migration from the Mediterranean Region via Southeast Asia.» MASUDA, K. 1986. Notes on the origin and migration of Cenozoic pectinids in the Northern Pacific. Paleontological Society of Japan, Special Papers, 29: 95-110, pls. 7-10. In T. Kotaka (Ed.), Japanesse Cenozoic mollusca: their origin and migration, vii, 255 p., pls. 1-21. [p. 100]
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Pecten albicans (Schroter); K. Masuda, 1986, Notes on the origin and migration of Cenozoic pectinids in the Northern Pacific, plate 9, figure 3.
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«Remarks: — Pecten excavatus Anton (Reeve, 1852, pI. 8, Sp. 33), a Recent species of Southern Japan, is related to the present species, but it can be distinguished by its somewhat smaller shell, more inflated right valve, more radial ribs which are flatly round-topped in the right valve and by the left valve which is slightly concave inwards from beak to ventral margin. Pecten altes [sic] Hertlein (1925, p. 8, pI. 2, figs. 1, 4), an Upper Miocene or Lower Pliocene scallop of California, can be distinguished from the present one by its small size and convexity, sulcated radial ribs of the right valve and the left valve having the flat-topped radial ribs as well as the interspaces.
The fossil specimens of the present species have been described from the Pleistocene of the Miura Peninsula, Kanagawa Prefecture by Yokoyama (1920) as Pecten laqueatus Sowerby, and subsequently it has been frequently recorded from various localities of Japan. As pointed out by Rehder (1944) Pecten laqueatus is a synonym of albicans. Grant and Gale (1931) concluded that the present species may be a synonym of Pecten humphreysii Conrad, a Miocene species of California. Recently Fleming (1957) suggested that Pecten albicans from Japan may have been derived from Pecten altes [sic] of the Pecten jacobaeus group. The writer is inclined to consider that the present species may have been derived from the southern scallops, probably from the Pecten benedictus group and may be the allopatric form of Pecten excavatus. Type locality: — Japan. Recent. Distribution: — Onma and Hiratoko formations, Ishikawa Prefecture; Nekoya and Kaizawa formations, Shizuoka Prefecture; Shibikawa formation, Akita Prefecture; Sawane and Haizume formations, Niigata Prefecture; Miyata formation, Kanagawa Prefecture; Tokyo formation, Tokyo Metropolis; Kiwada, Umegase, Sanuki, Kiyokawa, Numa formations, etc. Chiba Prefecture; Living in the Pacific (30º-42ºN.) and the Japan Sea (-42ºN.); Early Pliocene to Recent. Occurrence: — Rare in the coarse-grained sandstone of the Shibikawa formation; common in the medium-grained sandstone of the Onma formation; common in the silty medium-to coarse-grained sands of the Hiratoko formation.» MASUDA, K. 1962. Tertiary Pectinidae of Japan. Science Reports of the Tohoku University [2nd. Series - Geology], 33 (2): 117-238, pls. 18-27. [p. 201, 202]
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Pecten albicans (Schröter); K. Masuda, 1962, Tertiary Pectinidae of Japan, plate 23, figure 9.
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«Japanese fossil scallops referred to Pecten s. str., or to Vola or Notovola (synonyms of Pecten) occur only in the uppermost Cenozoic formations on either side of Tokyo Bay (Yokoyama, 1920, 1922). Pecten naganumana Yok., an extinct member of the jacobaeus group or uncertain affinity, occurs in the Naganuma Zone of the Lower Musashino Formation, now classed as Pliocene (Hatai and Nisiyama, 1952: 12). Three other zones now classed as Pleistocene (K. Hatai letter, april 1954) contain P. albicans, a species that apparently invaded Japan from America, where it has Miocene and Pliocene ancestors, (Grant and Gale, 1931). Yokoyama (1922, 1928) also recorded Pecten excavatus Anton (= sinensis Sow.) from the Upper Musashino, but his first record was based on young shells of albicans and his second on specimens of P. naganumana. It is doubtful if true excavatus occurs fossil in Japan (K. Hatai, letter, April 1954)
In Formosa, fossil Pecten (s. str.) are known only from the Byoritz Beds, classed as pliocene (Yokoyama,1928). The Upper Byoritz beds contain mollusca of a cooler sea than that of the present and are thus probably Pleistocene. Yokoyama recorded Pecten albicans (as laqueatus) and P. sinensis, but the specimen figured under the latter name is not the same as the P. excavatus Anton ( = sinensis Sow.) which now lives at Formosa (Kuroda, 1941, Plate12, Fig. 69, 70).» FLEMING, C. A. 1957. The genus Pecten in New Zealand. New Zealand Geological Survey, Paleontological Bulletin, 26: 1-69, pls. 1-15. [p. 18]
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«Specimens of this species [Pecten laqueatus, Sowerby] are not numerous, but easily recognized by their peculiar characters. The right valve is very convex with broad, flat, radiating ribs, whose number is normally eight, with one 01' two, rarely three, narrow secondary ribs on both sides of the shell. The left valve is slightly concave with narrower, flatly rounded radiating ribs whose normal number is seven or eight. The ears are nearly equal, with a shallow notch below the anterior one.
Fossil occurrence: — Miyata Zone (Shimo-Miyata and Kami-Miyata); Yokosuka Zone (Otsu); Upper Musashino of Oji and Shinagawa. Living: — Northern, Central and Western Japan.» YOKOYAMA, M. 1920. Fossils from the Miura Peninsula and Its Inmediate North. Journal of the College of Science, Imperial University of Tokyo, 36 (6): 1-193, pls. 1-20. [p. 160]
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Pecten laqueatus Sow.; M. Yokoyama, 1920, Fossils from the Miura Peninsula, plate 14, figures 9, 10.
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