Cryptopecten bullatus (Dautzenberg & Bavay, 1912)
DAUTZENBERG, P. & A. BAVAY. 1912. Les lamellibranches de l'Expédition du Siboga. Partie Systématique I: Pectinidés. In M. Weber (Ed.): Résultats des Explorations Zoologiques, Botaniques, Océanographiques et Géologiques Entreprises aux Indes Néerlandaises Orientales en 1899–1900, à bord du Siboga […]. Monographie 53b: 1-41, pls. 27, 28. E. J. Brill, Leiden. [p. 17, pl. 27, figs. 1, 2]
1912 Pecten (Chlamys) bullatus Dautzenberg & Bavay, 1912
1938 Cryptopecten alli Dall, Bartsch & Rehder, 1938
1983 Cryptopecten complanus Wang, 1983
1938 Cryptopecten alli Dall, Bartsch & Rehder, 1938
1983 Cryptopecten complanus Wang, 1983
P. Dautzenberg & A. Bavay, 1912, plate 27.
|
«Stat. 105. 6° 8' N., 121° 19' E. Archipel Sulu. 275 m. profondeur. 1 exemplaire (type).
Stat. 260. 2,3 milles N., 63° W. de "la pointe Nord de Nuhu Jaan, îles Kei. 90 m. profondeur. 2 exemplaires. Testa parva, parum crassa, depressa, aequivalvis et fere aequilateralis. Auriculae subaequales: anticae quam posticae tamen paullo majores. Valva supera costas 20 utrinque vesiculosas, quam interstitia transversim confertimque squamosas, praebet. Valva infera similiter, sed costis aliquantum angustioribus sculpta. Auriculae, praeter anticam valvae inferae, squamas simplices tantum exhibentem, costis radiantibus vesiculosis ornatae. Auriculae junctae breviter et late hiantes canaliculum utrinque efformant.
Color valvae superae extus intusque sordide albus, roseo late maculatus; valvae inferae extus albescens, intus vero albus et rubro variegatus. Altit. 13, diam. maj. 13 millim.; auricularum lat. 19 millim. Coquille petite, plutôt mince, déprimée, équivalve, presque équilatérale. Oreillettes subégales: les antérieures un peu plus grandes que les postérieures. Valve supérieure ornée de 20 côtes recouvertes par des squamules élevées qui se rejoignent et se soudent entre elles au sommet de maniére à former, de chaque côté, une rangée de vésicules disposées en séries alternantes; les intervalles, plus étroits que les côtes, sont garnis de squamules concentriques serrées. La sculpture de la valve inférieure est semblable à celle de la valve supérieure, mais ses côtes rayonnantes sont cependant un peu plus étroites. Les oreillettes, à I'exception de I'oreillette antérieure de la valve inferieure, qui n'a que des squamules simples, sont pourvues de côtes accompagnées de vésicules. Lorsque les deux valves sont assemblées, les oreillettes forment, par leur réunion, un canal largement ouvert de chaque côté, comme chez le Pecten pallium Lin.
Coloration externe et interne de la valve supérieure d'un blanc sale maculé de rose. Valve inférieure d'un blanc sale uniforme á I'extérieur et ornée, à I'intérieur, de petites taches rosées. Les trois exemplaires recueillis sont évidemment jeunes. Celui qui à servi de type à notre description est semblable aux deux autres, mais d'une taille double. La nature vésiculeuse des squamules ainsi que I'existence d'un canal au dessous du bord articulaire des oreillettes permettront sans doute de reconnaître cette espèce si on la rencontre plus tard à l'état adulte. Le P. pallium possède un canal semblable et aussi bien développé. Ce caractère qui existe aussi, mais plus atténué, chez les P. exasperatus, muscosus et chez quelques autres espèces, est sans doute lié au mode de locomotion de l'animal. Il y a lieu de remarquer que la forme des squamules du P. pallium n'est pas sans analogie avec celle des vésicules de notre espèce.» PHILIPPE DAUTZENBERG & ARTHUR BAVAY, 1912
|
«Cryptopecten bullatus differs from its locally sympatric living congener C. nux by having a thinner shell, a more weakly inflated right valve, and more delicate intercalary
commarginal sculpture. The present material slightly differs from the holotype in having a sturdier, more inflated shell, and more prominent sculpture. Specimens from eastern Australia (AMS) eastwards to the Kermadec Islands are generally larger (height up to ca. 30 mm) than specimens from Indonesia and the Philippines (height up to ca. 20 mm, ZMA). The Wanganella Bank specimens are the southernmost record for C. bullatus.» DIJKSTRA, H. H. & B. A. MARSHALL. 2008. The recent Pectinoidea of the New Zealand region (Mollusca: Bivalvia: Propeamusiidae, Pectinidae and Spondylidae). Molluscan Research, 28 (1): 1-88, figs. 1-70. [p. 69]
|
Cryptopecten bullatus (Dautzenberg & Bavay, 1912); H. H. Dijkstra & B. A. Marshall, 2008, The recent Pectinoidea of the New Zealand region, figures 55G, 55H.
|
«Remarks.— The number of ribs, in contrast to the other species of the genus, varies with the size of the shell; the specimens from Hawaii are somewhat more oblique in shape and have a lower number of ribs than specimens of about equal size from the Philippines and Indonesia. The specimens from South Africa from 250 and 400 m depth closely resemble the Hawaiian specimens in shape and number of ribs. One of the valves of the South African specimens dredged at 100 m depth resembles the Philippine form, the other valve is intermediate in shape, but has the same number of ribs as the Philippine form. Therfore I think that both forms represent one species, but that the differences are due to the differences in bathymetric distribution as shown by the samples from South Africa.
In Japan this species was known under the name Cryptopecten tissotti, but the type specimen of Pecten tissotti Bernardi, 1861 (kept in the MP), represents a juvenile Aequipecten (Perapecten) flabellum (Gmelin, 1791) (see also Dijkstra, 1987: 8). Type-locality.— 6°8' N 121°19' E, Sulu Archipelago, at 275 m. Distribution.— The species can be found from South Africa to the Hawaiian Islands.» WAGNER, H. P. 1989. The genus Cryptopecten Dall, Bartsch & Rehder, 1938, in the Indo-Pacific (Mollusca; Bivalvia; Pectinidae). Basteria, 53: 53-62, figs. 1-18. [p. 61]
|
Cryptopecten bullatus (Dautzenberg & Bavay, 1912); H. P. Wagner, 1989, The genus Cryptopecten Dall, Bartsch & Rehder, 1938, in the Indo-Pacific, figures 14 (holotype of C. alli Dall, Bartsch & Rehder), 15, 16.
|
«Remarks.— Since Yoshihara's (1902) description of several Japanese specimens, many Japanese authors have erroneously called the present species Pecten tissotii Bernardi, 1858. This confusion seems to have arisen from Dunker (1882), who assigned a Japanese specimen (not illustrated) to P. tissoti [sic] Bernardi with a query. In the original description of. P. tissotii, Bernardi (1858) did not give any indication about the locality, though Pecten swiftii Bernardi, 1858, described in the same article as a collection from the Gulf of Tartary, is a well-known species from north Japan. The original figure of P. tissotii (Bernardi, 1858, pl. 1, fig. 2) is at a glace similar to the present species in general outline, but clearly differs from it in the larger number of radial ribs, more sigmoidal frontal margin of left anterior wing, and scarcely impressed radial ribs on the inner surface (suggesting better-developed inner shell layer).
Recently Poutiers (1981) identified a solitary valve sampled by the Musorstom expedition from Lubang of the Philippines (217-230 m in depth) with Cryptopecten alli. He said, "The species described and figured by Habe (1964) under the name of 'Cryptopecten tissotii (Bernardi)' does not correspond to the true Pecten tissotii of Bernardi (J. Conchyl. 1858, p. 91, pl. 1, fig. 2), the type of which, preserved in the Laboratoire de Malacologie du Museum d'Histoire naturelle de Paris, was examined by the present author" [translated from French]. Moreover, according to Dr. T. R. Waller's personal communication (May 27, 1981), the type specimen of P. tissotii in Paris seems to belong to Aequipecten flabellus (Gmelin, 1791), which is actually an eastern Atlantic species. All of the examined specimens from various stations around Japan and the Philippines agree well in every essential character with the Hawaiian specimens of Cryptopecten alli, including the holotype. Thus I once applied the specific name of C. alli to the species under consideration (Hayami, 1982). Subsequently, however, I recognized that the illustrated specimen (holotype) of Pecten (Chlamys) bullatus Dautzenberg and Bavay, 1912, in Amsterdam is nothing but an immature individual of the same species. According to Dr. T. R. Waller's photographs, this specimen shows weak convexity of both valves and about 20 radial ribs, each of which consists of a narrow central ridge and a pair of hollow parts covered with regularly alternate imbricated scales; that is to say, every diagnostic character of C. alli is exhibited in this specimen. Consequently, C. alli should be regarded as synonymous with C. bullatus. The geographic variation of. C. bullatus does not seem to be wide; none of the samples from Hawaii, the Philippines or Japan shows any conspicuous local characteristics. In the National Museum of Natural History, however, there is an aberrant small sample (USNM 773983) from Nasca Ridge in the eastern Pacific (25°44'5,85°25'W, 228 m). All the specimens (three right valves) in this sample are nearly white, and this is certainly not due to abrasion. Because such albinism is rarely met with in samples from the central and northwestern Pacific, this sample may represent an isolated local population. Fossils of. C. bullatus seem to be rare. The Late Pleistocene fossil sample Kk (B) from the Wan Formation of Kikai Island is composed of somewhat smaller specimens with slightly more numerous radial ribs than Recent specimens. The structure of radial ribs and other characteristics are, however, essentially the same, and subspecific distinction may be unnecessary. A small left valve from the Late Pliocene Shinzato Formation of Okinawa, which was illustrated under the name of Aequipecten sp. by Noda (1980), can be regarded as an immature individual of this species. Distribution.— The present species is widely distributed on the lower sublittoral and upper bathyal sandy substrates in the central and northwestern Pacific. In addition to the type locality and several other stations around the Philippines, it has been known from a number of stations around the Hawaiian and Japanese Islands and a station on Nasca Ridge in the eastern Pacific, as is partly recorded in the list of examined samples. Fossil occurrence of C. bullatus is so far restricted to some Pliocene and Pleistocene deposits of the Ryukyu Islands. Late Pliocene (ca. 2.0 Ma) to Recent.» HAYAMI, I. 1984. Natural history and evolution of Cryptopecten (A Cenozoic-Recent Pectinid Genus). The University Museum, The University of Tokyo, Bulletin, 24: 1-149, pls. 1-13.[p. 98]
|
Cryptopecten bullatus (Dautzenberg and Bavay); I. Hayami, 1984, Natural history and evolution of Cryptopecten, plate 1, figures 1-6.
Pecten tissotii; A. C. Bernardi, 1858, Description d'spèces nouvelles, plate 1, figure 2.
|