Semipallium coruscans coruscans (Hinds, 1845) 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 : 294-296

Semipallium coruscans coruscans (Hinds, 1845) , comb. n.

(Figs 31p–32)

Pecten coruscans Hinds, 1845: 61 , pl. 17, fig. 3; Reeve, 1853: pl. 33, fig. 149. Type locality: Port Anna Maria, Nukuhiva , Marquesas Islands, 13 m.

Chlamys coruscans ; Kilburn & Rippey, 1982: 171, 216, textfig. 139, pl. 38, fig. 10; Steyn & Lussi,1998: 212, fig. 856.

Chlamys coruscans coruscans ; Waller, 1972: 231, pl. 1, figs 1–19, text figs 2, 12, 14 (synonymy, type data, description, functional morphology, ecology, distribution, discussion).

Pecten cuneolus Reeve, 1853 : species 131, pl. 29, fig. 131; Küster & Kobelt, 1888: 232, pl. 61, fig. 9. Type locality: unknown (see note below).

Chlamys cuneolus ; E. A. Smith, 1910: 212.

Pecten schmeltzii Dunker in Küster & Kobelt, 1888: 272, pl. 71, figs 5–6.

Pecten sulphureus Dunker in Küster & Kobelt, 1888 (non Ostrea sulphurea Gmelin, 1791 ): 276, pl. 72, figs 5–6. Type locality: Viti-Inseln ( Fiji).

Chlamys cellularis Oliver, 1915: 554 , pl. 12, fig. 46. Type locality: Sunday Island (Raoul Island), Kermadec Islands.

Pecten eucosmia Turton, 1932: 222 , pl. 57, fig. 1549. Type locality: Port Alfred , in driftwood.

Chlamys eucosmia ; Barnard, 1964: 427, fig. 13b.

Description: Shell height to 20 mm (averaging 10–15 mm), orbicular to obliquely oblong,

RV more convex than LV, auricles unequal, umbonal angle ca. 85–90°. Both valves 31 32

Figs 31–32. Semipallium coruscans coruscans (Hinds, 1845) : NMSA 2425, Durban, Natal, pv, 16.9 x 17.1 mm. 31. LV exterior. 32. RV exterior.

sculptured with 12–15 nearly regularly spaced, unequally developed, primary tripartite radial ribs, flanked with 1–2 intercostal secondary radial riblets near ventral margin. Epidermal microsculpture reticulated, when eroded more granulated, throughout growth. Anterior auricles larger than posterior with 4–8 radial riblets, posterior 2–4 weak riblets. Hinge line nearly straight, postero-dorsal auricle slightly declivous. Inner surface somewhat plicated, ventral margin crenated. Cardinal crura well developed. Auricular denticles (1–4) sometimes present on postero-marginal area, on antero-marginal area one. Byssal fasciole wide, byssal notch moderately deep. Active ctenolium well developed with 3–7 teeth (commonly 4–5). Colour variable, usually cream with white, red, purple or brown blotches or rays, plus a few unpigmented primary ribs; sometimes uniform white, yellow or red.

Type material: P. coruscans ; lectotype BMNH 19709 , designated by Waller (1972: 231). P. cuneolus : lectotype BMNH 1969140.1 , designated by Waller (1972: 231); paralectotype, BMNH 1969140.2 . P. schmeltzii : five possible syntypes MNHB . P. sulphureus : holotype MNHB . P. eucosmia : holotype OUZM Turton No. 1549. C. cellularis : holotype (lv) CM M.688. All seen by HD.

Regional data (all NMSA, unless otherwise stated, selected records): MOZAMBIQUE: off Pemba, 15 m, amongst coral rubble, sandy bottom, live ( HD6472 ); Bazaruto Island , North Reef , under rocks, intertidal (G1384: E. Roscoe); Benguerua Island , Two Mile Reef, live (G2167: E. Roscoe); Baia dos Cocos, near Jangamo, live (V2640: J. Rosado); Inhaca Island , live ( NMSA 4483 : P. H. Boshoff). SOUTH AFRICA: Zululand: Between Bhanga Nek and Kosi Bay , 5–9 m, reef amongst algae (S1423: D. Herbert et al.); Kosi Bay , main reef, 1–4 km S of estuary mouth, 18–22 m, dead (S1047: D. Herbert et al ..); Sodwana Bay, Two-Mile Reef, outer ledge, 14–17 m, live (D5095: D. Herbert); Ledsman Shoal, 20 m, on dead Acropora coral head (B3009, ex CSIR Water Research Unit); same data, 15 m, inside compacted coral rubble and sand, live (E2260: Oceanographic Research Institute). Natal: off Durban Bluff, 20–22 m, dead (B5457: RK, R. Fregona); Durban, dead ( NMSA 2425 : H. C. Burnup, recorded by E. A. Smith 1910); off Umlaas Canal, 75 m, muddy sand (D1624: NMDP); Isipingo (4482: H. C. Burnup); Aliwal Shoal, off Scottburgh, 10–20 m, sand, dead (S8037: D. Herbert); Ifafa (2426: H. C. Burnup); Port Shepstone, dead ( NMSA 4484 : H. C. Burnup) .

Distribution: Throughout tropical Indo-West Pacific, as far south as southern Natal, although not yet recorded from the Red Sea and Persian Gulf. Turton’s specimen from Port Alfred (described as Pecten eucosmia ) was taken from a drift log, and does not demonstrate its occurrence south of KwaZulu-Natal.

Habitat: Living byssally attached to rocks or corals, often nestling in crevices, commonly in shallow waters (intertidally to about 20 m).

Remarks: Reeve (1853) described P. cuneolus from an unknown locality; the locality ‘Durban’, subsequently scribbled on the type label by E. A. Smith, refers to a specimen sent to the latter by Burnup, and does not reflect the likely origin of Reeve’s material. P. cuneolus , P. schmeltzii and P. sulphureus are in all respects similar to P. coruscans . HD has examined possible syntypes (5 specimens) of P. schmeltzii from Fiji and Upolu ( Samoa) in MNHB; the figured specimen is not present in LMA. The figured holotype (a yellow specimen) of P. sulphureus (MNHB) is labelled ‘ Pecten sulphureus Dkr Viti Ins.’. C. cellularis from the Kermadec Islands, although somewhat more solid and oblique than typical S. coruscans ( Dijkstra & Marshall, 1997), appears to be another synonym. The holotype of P. eucosmia from Port Alfred also agrees well with the types of Pecten coruscans (for P. eucosmia sensu Boshoff 1965 , see Volachamys fultoni ).

The morphological characters of Pecten coruscans conform most closely to those of genus Semipallium .