Veprichlamys africana, Dijkstra & Kilburn, 2001

Dijkstra, H. H. & Kilburn, R. N., 2001, The family Pectinidae in South Africa and Mozambique (Mollusca: Bivalvia: Pectinoidea), African Invertebrates 42, pp. 263-321 : 302-305

Veprichlamys africana sp. n.

( Figs 40–43 )

Description of holotype (RV): Shell fragile, up to 36 mm high, obliquely ovate, rather compressed, inequilateral, auricles unequal, umbonal angle ca. 90°. RV sculptured with numerous (ca. 25) irregularly spaced, radial costae on central part of disc, increasing to ca. 50 near ventral margin, commencing at 2 mm shell height. Radial costae squamose. Preradial stage smooth (somewhat eroded). Intercostal microsculpture of antimarginal striae. Anterior auricle larger than posterior, sculptured with 4 prominent squamose radial riblets, one weak radial riblet on posterior auricle. Anterior dorsal margin with prominent scales. Hinge line straight. Inner surface somewhat plicate. Resilifer triangularly oblong. Auricular crura well developed. Byssal notch rather deep, byssal fasciole broad.Active ctenolium with 5 teeth on suture. Colour exterior creamy, interior nacreous.

Additional description of paratype (LV) (NMSA 5735): Shell fragile, up to 41 mm high, somewhat obliquely ovate, rather compressed, slightly inequilateral, auricles unequal, umbonal angle ca. 90°. LV sculptured with ca. 20 regularly spaced, primary radial costae on central part of disc, increasing with numerous secondary intercalated radial riblets (ca. 20) near ventral margin, commencing at 1 mm shell height. Radial costae squamose. Preradial microsculpture of fine commarginal lamellae, intercostal

41 40

43 42

microsculpture of irregular antimarginal striae. Anterior auricle larger than posterior, sculptured with 5 prominent squamose radial riblets, 2 weak radial riblets on posterior. Auricular microsculpture of irregular antimarginal striae. Hinge line straight, posteriorly somewhat declivous. Inner surface plicate. Resilifer oblique oblong, resilial teeth very weak, dorsal teeth absent. Auricular crura well developed. Colour exterior greyish, interior silky.

Type locality: SOUTH AFRICA: Natal : off Amanzimtoti, 30°02.9'S, 31°05.8'E, 350 m, muddy sand, NMDP Stn XX 67, 9.vii.1985 .

Type material: Holotype NMSA D1452 /T1728, RV, data as above, dimensions H 35.9 mm, L 31.5 mm . Paratypes (6 LV, 5 RV in total): MOZAMBIQUE: 60 miles S of Zavora, 130 miles E of Inhaca, 494 m, dead, leg. A. Krige, don. K. Eastwood ( NMSA 8221 /T1679: 1 RV); Ponta da Barra Falsa , 275–350 m, mud, dead, 1996 ( ZMA Moll. 3.99.003: 1 LV + 1 RV) . SOUTH AFRICA: Natal : same data as holotype ( NMSA V7830 / T1729: 1 LV + 1 RV); off Natal, dead, R. Cruickshank, v. 1970 ( NMSA 5735 /T1706: 1 LV) . Transkei : off Whale Rock, 32°00.9'S, 29°21.8'E, 400–420 m, coarse sand, old shell debris, stones, dead, NMDP Stn M 7, 20.vii.1982 ( NMSA V7152 /T1730: 2 LV + 1 RV); off Mendu Point, 32°22.0´S, 29°01.2´E, 405–420 m, fine sand, dead ( NMSA C5009 / T1727: 1 LV); off Qora River, 400 m, sand, dead, NMDP Stn U 8, 14.vi.1983 ( NMSA C6587 /T1726: 1 RV) .

Distribution: Continental slope of southern Mozambique to eastern Transkei.

Habitat: At present only single valves are known, from ca. 350–500 m on coarse sand or mud.

Discussion: Veprichlamys africana differs from the Australian V. perillustris ( Iredale, 1925) in its more ovate to orbicular shape ( V. perillustris is more obliquely ovate), in having more numerous secondary intercalated radial riblets, which are almost absent in V. perillustris , and by the more prominent antimarginal microsculpture. Veprichlamys kiwaensis ( Powell, 1933) of New Zealand resembles V. africana most closely, but differs in having a more obliquely ovate shape, having fewer intercalated secondary radial riblets, by its more numerous commarginal lamellae in the preradial stage, and by having finer antimarginal intercostal striae. The Japanese Veprichlamys jousseaumei (Bavay, 1904) differs from V. africana in its smaller size (height <25 mm) and more orbicular shape, in its more numerous, regularly spaced, primary radial costae (ca. 30-38), and in its fewer secondary intercalated radial riblets. Veprichlamys incantata (Hertlein, 1972) from the Galapagos differs from V. africana mainly in attaining a larger size (up to ca. 55 mm high), in its more numerous secondary intercalated radial riblets, and in having more prominent and erect scales on the radial costae. Veprichlamys versipellis Dijkstra & Kastoro, 1997 , of Indonesia, differs from V. africana in having a reticulated microsculpture in its early radial stage and a finer antimarginal microsculpture in the late radial stage, and by having larger auricles.

Etymology: Latin africanus, adj. = African.

Remarks: The available specimens from Mozambique and northern South Africa are all dead-collected and somewhat corroded, especially those from South Africa. It is presumed that Veprichlamys africana inhabits deeper bathyal waters, like V. perillustris (in ca. 460 m) and V. kiwaensis (to ca. 1000 m) (unpublished data, Dijkstra). However,

it is not impossible that in the case of V. africana these valves have been derived from Pleistocene deposits by slope erosion.

Figures

Figs 40–43. Veprichlamys africana sp. n. 40–41. Paratype, NMSA 5735, off Natal, 40.6 x 36.0 mm. 40. LV exterior. 41. LV interior. 42–43. Holotype, NMSA D1452, off Amanzimtoti, Natal, 350 m, 35.9 x 31.5 mm. 42. RV exterior. 43. RV interior.