Bractechlamys nodulifera (Sowerby, 1842)

Dijkstra, H. H. & Kilburn, R. N., 2001, The family Pectinidae in South Africa and Mozambique (Mollusca: Bivalvia: Pectinoidea), African Invertebrates 42, pp. 263-321 : 274-276

Bractechlamys nodulifera (G. B. Sowerby 2nd, 1842)

(Figs 8–9)

Pecten noduliferus Sowerby, 1842: 64 , pl. 13, figs 38–39, pl. 16, fig. 94; von Martens, 1880: 313. Type locality: not given (= Mauritius, here designated).

Chlamys (Nodipecten) nodulifer ; Lamy, 1935: 312.

Chlamys noduliferus ; Smith, 1910: 212.

Nodipecten noduliferus ; Grau, 1959: 128; Oliver, 1982: 13; Rombouts, 1991: 47, pl. 16, figs 6–6a; Wagner

(1991): 24.

Pecten (Nodipecten) noduliferus (in part); Boshoff, 1965: 133, pl. 13, fig. 2.

Decatopecten noduliferus ; Abbott & Dance, 1982: 307, fig.

Bractechlamys noduliferum ; Waller, 1986: 41.

Lyropecten noduliferus ; Anonymous 1991: 2, fig. 1.

Pecten corallinoides (non d’Orbigny in Webb & Berthelot, 1839); Reeve, 1852: pl. 6, fig. 27.

Chlamys corallinoides (non d’Orbigny); Bosch & Bosch, 1982: 160, fig.

Description: Shell up to 50 mm high, adult height usually ca. 30 mm, solid, RV slightly more convex than LV, equilateral, suborbicular, auricles unequal, umbonal angle ca. 90°. Both valves with prominent regularly placed, somewhat undulated and nodose, radial costae (9); secondary radial riblets on costae (4–9), starting in central part of disc and sometimes very weak, due to noduliferous character of costae; also present in intervals (2–5) and strongly developed near ventral margin. Disc covered with closely spaced microscopic commarginal lamellae. Anterior auricle larger than posterior, with radial riblets (ca. 4–8), slightly weaker on posterior auricle. Auricle of RV with strong,

9

Figs 8–9. Bractechlamys nodulifera (Sowerby, 1842) : NMSA D9163, off Boteler Point, Zululand, 50 m, pv, 37.2 x 37.1 mm. 8. LV exterior. 9. RV exterior.

squamose sculpture on antero- and postero-dorsal margins. Hinge line straight. Byssal fasciole moderately wide, byssal notch rather deep.Active ctenolium with 3–7 teeth on suture. Resilifer elongate, triangular.Auricular crura well developed. Inner surface near ventral margin plicated. Colour variable, often vivid red, pink or brown with cream, yellow or white spots, sometimes more uniform in colour. Interior whitish and reddish, near dorsal margin sometimes also brownish.

Type material: Not traced in the BMNH type collection, nor in their general collection .

Regional data: MOZAMBIQUE: Fernao Veloso Bay, Nacala, 2–3 m, amongst rubble, algae, dived, live (HD3712); SW Memba Bay, 0.6 m below LST, on Thalassodendron (NMSA H4471); Mozambique Bay, S Chembas, 2 m, rocky, Thalassodendron (NMSA H4470: K. J. Grosch); SW Lunga Bay, 0.6 m, in Thalassodendron (NMSA H4472: K. J. Grosch); SW Conducia Bay, E of Conducia, 0.6 m, sand flats, on Thalassodendron (NMSA H4469: K. J. Grosch); Conducia Bay (NMSA H4474: K. J. Grosch); Inhambane Bay, dead (NMSA H7425: B. J. Young); Cabo dos Correntes, 30–45 m, rubble, muddy sand, trawled, live (HD 6442); off Quissico, 110–150 m, juv. (L4770: J. Rosado). SOUTH AFRICA (all NMSA: NMDP, unless otherwise stated): Zululand: Kosi Bay, main reef, 1–4 km S of mouth, 18–22 m, dead (S1013: D. Herbert et al.); NE of Kosi Bay, 49 m, sand, stones, kelp, dead (S5642); SE of Kosi Bay, 48 m, sand and rubble, live (D8714); same loc., 45–47 m, red algae, sponges, live (D6272); same loc., 50 m, medium sand, rubble, live (D8937); off Boteler Point, 50 m, coral rubble, lithothamnion, dead (D7428); same loc., 50 m, coral rubble, lithothamnion, dead (D9163); Sodwana Bay, Sponge Reef, ca. 33 m, dead (E804: D. Herbert et al.); same loc., Two Mile Reef, 10–15 m, dead (D1845: D. Herbert); NE of Liefeldt’s Rocks, 50 m, lithothamnion, medium sand, dead coral rubble, dead (E4314); same loc., 50 m, lithothamnion, stones, some coarse sand, dead (E4389); off Gypsey Hill, 52 m, fine sand, dead (E3403). Natal: Durban, probably living (A513: J. Quekett).

Distribution: Tropical Indian Ocean (except Red Sea), as far south as northern Zululand (with one vagrant example from Durban).

Habitat: Living byssally attached to corals or between coral rubble on sandy bottoms at littoral to sublittoral depths.

Remarks: Bractechlamys nodulifera was first recorded from South Africa by Smith (1910); the specimen on which this record was based is in the NMSA collection. Individuals from Mozambique and South Africa are typical, although Mozambican material is unusual in colour, being brown with yellow dots. In the literature B. nodulifera has sometimes been misidentified as B. corallinoides (d’Orbigny in Webb & Berthelot, 1839) of the tropical E Atlantic.The latter species differs in being slightly more orbicular, with more numerous commarginal plicae, which are more strongly nodose. Hertlein (1935: 27) and Kay (1979: 525) synonymised the Hawaiian B. langfordi ( Dall, Bartsch & Rehder, 1938) , with the present species. However, B. langfordi is smaller in size (up to ca. 30 mm high), more strongly convex, and has more numerous and weaker nodules on the radial costae; also, its coloration is brighter orange-yellow. Finally, Rombouts (1991: 47) considered Pecten arthriticus Reeve, 1853 to be a junior synonym of B. nodulifera , but J. T. Smith (1991: 88) showed this to be a valid species of Nodipecten from the tropical E Pacific.

10 11

Figs 10–11. Decatopecten amiculum ( Philippi, 1851) : NMSA H4491, Conducia Bay, Mozambique, pv, 45.8 x 44.9 mm. 10. LV exterior. 11. RV exterior.