Volachlamys fultoni (G. B. Sowerby III, 1904)
SOWERBY III, G. B. 1904. Mollusca of South Africa (Pelecypoda). Marine Investigations in South Africa, 4: 1-19. [p. 2, pl. 6, fig. 5]
1904 Chlamys fultoni G. B. Sowerby III, 1904
G. B. Sowerby III, 1904, plate 6.
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«Shell nearly orbicular, rather thin, compressed, equivalve, dull purplish brown, irregularly interrupted with white markings. Auricles rather large, slightly unequal, posterior rectangular, anterior slightly laterally produced above and sinuous below. Valves furnished with 17 rounded, rather elevated equidistant ribs, the interstices being about the same width as the ribs, and regularly concave, without radiating striae; both ribs and interstices are traversed by thin lamellae, which are squamosely raised on the ribs, particularly on the lateral ones. The right valve is somewhat smoother and lighter in colour, but otherwise presents the same character as the left. The anterior auricle of the right valve is strongly laminated, otherwise they are regularly costate.
Height, 33; width, 34; depth, 11 millim. Hab.:— Amatikulu, Conical Hill. N.W., miles; depth, 26 fathoms; bottom, mud. The shells of this species vary considerably in pattern; while in the type the white markings arc rather large and few, in some the white predominates. In general style the shell somewhat resembles C. tranquebaricus, Gmelin, but it is broader in form, and has less numerous ribs, with no signs of longitudinal striae or riblets between them.» GEORGE BRETTINGHAM SOWERBY III, 1904
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«Description: Shell up to 40 mm high, usually somewhat smaller, compressed, suborbicular, nearly equivalve, equilateral, auricles slightly unequal, umbonal angle ca. 90º. Both valves with numerous prominent radial plicae (16–18, usually 17), which are somewhat squamose near ventral margin, and fine, closely spaced, commarginal lamellae in interstices on RV and in late ontogeny on left; granular microsculpture in interstices and sometimes on posterior auricle of LV; lamellae and microsculpture variable in development, sometimes almost absent (Barnard 1964: 429). Auricles with 5–7 small radial riblets, somewhat nodulous, and fine, closely spaced, commarginal lamellae on anterior auricle of LV, more coarsely laminated on anterior auricle of right. Byssal fasciole moderately wide, byssal notch deep. Active ctenolium well developed with 4–6 teeth on suture. Inner surface slightly plicated to more angulated near ventral margin. Cardinal crura weak. Resilifer oblong, oblique; resilial denticles absent. Colour variable, creamy-brown, purplish-brown with white or cream blotches or streaks, sometimes almost uniform brown or white.
Type material: Lectotype (H 33.5 mm, L 33 mm, D 11 mm) BMNH 1904.12.23.164 herein designated; paralectotype (LV) SAM 14970. Regional data: MOZAMBIQUE: off Maputo, 120 m, muddy sand, live (HD6471); Maputo, beach drift (5004); Beira, reclamation dump, dead (J5112, G8177: E. Roscoe). SOUTH AFRICA: Zululand: off Neill Peak (Cunge), 50 m, mud, dead (E3881); Tugela Bank, 41 m, fine mud, dead (A7158); off Matigulu River mouth, 70 m, coarse sand, broken shell, dead (S744); off Tugela Bluff, 60–65 m, mud, dead (E9060). Natal: off Mvoti River mouth, 70 m, soft mud, dead (E9159); off Sheffield Beach, 50 m, fine sandy mud, dead (E9247); same loc., 50 m, fine sand, dead (E9598); SE of Sheffield Beach, 50 m, sandy mud, dead (E5082); off Tongaat Bluff, 50 m, mud, dead (E9941); same loc., 50 m, soft mud, algal debris, dead (S180, S181); off Durban, 274 m, dead (9934); Durban Bay, shallow dredgings (B1663); off Isipingo, 55 m, dead (B3045); off Umlaas Canal, 50 m, fine sand, dead (D1046). TRANSKEI: off Mbotyi, 45 m, mud, dead (C7129); off Mzimhlava R., 50 m, clay, thick mud, dead (C7120); off Mgazi, 48 m, mud, dead (C3268); off N’tafufu River, 50 m, mud, sand, dead (C1039). Eastern Cape region: off East London, 70 m, muddy sand, schizamminid forams, dead (B8330); same loc., 70 m, muddy sand with lumps of black mud, dead (B8274); same loc., 70 m, fine sand, broken shells, dead (B8414, B8460). Distribution: Central Mozambique to the eastern Cape, South Africa, also Malagasy Republic. Habitat: Living byssally attached to rocks, or free, on muddy bottoms on continental shelf, living mainly in 40–70 m, sometimes deeper. Remarks: A specimen identified as Chlamys eucosmia in the Boshoff collection in NMSA is actually a juvenile of the present species. Volachlamys fultoni closely resembles V. tranquebaria (Gmelin, 1791) from N and NE Indian Ocean, but the latter species is more convex and more oblong, and is sculptured with more numerous radial plicae (18–20) but fewer secondary interstitial radial riblets; it is also more brightly coloured. Granular microsculpture is also present in early ontogeny in V. tranquebaria, and (more strongly) in V. cumingii (Reeve, 1853). Smooth individuals such as occur in the Japanese V. hirasei (Bavay, 1904) have never been observed in V. fultoni.» DIJKSTRA, H. H. & R. N. KILBURN. 2001. The family Pectinidae in South Africa and Mozambique (Mollusca: Bivalvia: Pectinoidea). African Invertebrates, 42: 263-321.[p. 314, 315]
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Volachlamys fultoni (G. B. Sowerby 3rd, 1904): H. H. Dijkstra & R. N. Kilburn, 2001, The family Pectinidae in South Africa and Mozambique, figures 54, 55.
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