Argopecten felipponei (Dall, 1922)
DALL, W. H. 1922. Two new bivalves from Argentina. The Nautilus, 35 (2): 58-59. [p. 58]
1922 Pecten (Chlamys) felipponei Dall, 1922
Flexopecten felipponei (Dall, 1922); B. K. Raines & G. T. Poppe, 2006, A Conchological Iconography, The Family Pectinidae, plate 56, figures 1-5.
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«Shell rounded, the adult slightly oblique, rather compressed, polished, scarlet or rosaceus, usually with zigzag irregular streaks of white on the left valve; the ears paler; hinge line straight, the ears rather large, subequal, in the left valve with only incremental sculpture, in the right valve the anterior ear has four or five radial ridges more or less imbricated, and a ctenolium with five short teeth; sculpture of the left valve comprising five obscure flattened radial ribs with the interspaces obscurely radiately striate; there is no microscopic reticulation; on the right valve the ribbing is obsolete; length of shell 38; of hinge-line 28; height 40; diameter 8 mm.
The shell bears some resemblance to Kobelt's figure of P. danicus in the Conchylien Cabinet, but is on the whole a remarkably distinct species. The material studied comprises a well-known left valve (U. S. Nat. Mus. Cat. No. 333374) and in Dr. Felippone's collection another (1706) somewhat smaller, and a complete young pair (1709).» WILLIAM HEALEY DALL, 1922
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«The non-commercial Flexopecten felipponei formed a monophyletic group with the two subspecies of Aequipecten tehuelchus. Waller (1991, 2006) concluded that Flexopecten s.s. would be related to Aequipecten and restricted to the Mediterranean and adjacent eastern Atlantic with a single ‘outlier’ species, F. felipponei, occurring in the western South Atlantic. Orensanz et al. (1991), on the examination of soft tissue and simultaneous hermaphroditism of numerous individuals with intermediate characters, proposed that ‘F.’ felipponei would be only a phenotypic variant of A. tehuelchus, a hypothesis supported by our results. We found that Flexopecten glaber is grouped together with Aequipecten opercularis within the Pectinidae, both being phylogenetically distant from F. felipponei. This result is in agreement with those of Canapa et al. (2000), but in contrast with the results of Waller (1991) who placed Flexopecten as a member of the Decatopecten group, distant from Aequipecten.
Our phylogenetic reconstruction suggests that the clade formed by the three morphotypes of the Tehuelche scallop distributed along the south-western Atlantic Ocean is more closely related to the genus Argopecten from the Eastern Pacific and North and Central-Western Atlantic than to the other members of the genus Aequipecten, including the type species of the genus, Aequipecten opercularis (Linnaeus 1758), a species distributed in the Norwegian and Mediterranean seas (Huber, 2010). Aequipecten tehuelchus was originally classified in Chlamys (d’Orbigny 1842) and considered a species of this genus until Waller (1991) and Del Río (1992) transferred it to Aequipecten, even though Aequipecten is primarily distributed to the North Atlantic. A more comprehensive phylogenetic reconstruction of the family Pectinidae (Alejandrino et al., 2011; but see also: Saavedra & Peña, 2006; Puslednik & Serb, 2008; Feng et al., 2011) showed that the monophyletic genus Chlamys, including the type species Chlamys islandica (O. F. Müller, 1776), is very distant to both genera Argopecten and Aequipecten. In our phylogeny, the Tehuelche scallop is located in a basal position within the clade formed by the species belonging to the genus Argopecten. Therefore, we recommend transfer of the species including the forms: A. t. tehuelchus, A. t. madrynensis and Flexopecten felipponei, to the genus Argopecten Monterosato, 1889.»
TROVANT, B., L. E. REAL, A. M. PARMA, J. M. ORENSANZ & N. G. BASSO. 2018. Evolutionary relationships of the Tehuelche scallop Aequipecten tehuelchus (Bivalvia: Pectinidae) from the south-western Atlantic. Journal of the Marine Biological Association of the United Kingdom, 2018: 1-9, figs. 1-3. [p. 6, 7]
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«Phenotype variation of the Tehuelche scallop. To the left: Flexopecten ‘felipponei’ of two different sizes; to the right at the top, Aequipecten tehuelchus
‘tehuelchus’ and below, Aequipecten tehuelchus ‘madrynensis’»; B. Trovant, L. E. Real, A. M. Parma, J. M. Orensanz & N. G. Basso, 2018, Evolutionary relationships of the Tehuelche scallop Aequipecten tehuelchus (Bivalvia: Pectinidae) from the south-western Atlantic, figure 1. |