Laevichlamys lemniscata (Reeve, 1853)

Dijkstra, H. H. & Kilburn, R. N., 2001, The family Pectinidae in South Africa and Mozambique (Mollusca: Bivalvia: Pectinoidea), African Invertebrates 42, pp. 263-321 : 289-291

Laevichlamys lemniscata (Reeve, 1853)

( Figs 25–26 )

Pecten lentiginosus Reeve, 1853 : pl. 35, fig. 170 (renamed Pecten lemniscatus Reeve, 1853 : in errata) Type locality: unknown, here designated as Rèunion Is., Mascarenes .

Laevichlamys lemniscata ; Waller, 1993: 204.

Pecten squamosus (non Gmelin, 1791); Sowerby, 1897: 28; Barnard, 1964: 420; idem, 1974: 761 Chlamys (Chlamys) liltvedi Wagner, 1984: 3 , figs 1–4. Type locality: Sodwana Bay, Zululand , 18 m, under rocks on reef. Syn. n .

Chlamys liltvedi ; Steyn & Lussi, 1998: 212, fig. 860.

Description: Shell height to 50 mm (average ca. 35 mm), suborbicular to somewhat obliquely oblong, compressed, equiconvex or RV slightly more convex than LV, somewhat inequilateral, auricles unequal, umbonal angle ca. 90°. Both valves sculptured with numerous, irregularly spaced, squamous radial ribs, several prominent on LV (6– 9) with strongly developed scales.Antimarginal striated microsculpture in early ontogeny, sometimes throughout ontogeny near postero-lateral area on LV, commarginal lamellated microsculpture on anterior auricle of LV, sometimes throughout ontogeny near anterolateral area of LV, shagreen (reticulated or granulated) microsculpture absent. Hinge line straight, postero-dorsal auricle slightly curved. Inner surface weakly plicated, most strongly around periphery. Byssal fasciole wide, byssal notch deep. Active ctenolium well developed with 6–9 teeth on suture. Cardinal crura weak. Resilifer oblong, oblique. Colour variable, creamy, yellowish, orange, reddish or brownish with lighter and darker dots, sometimes uniformly coloured.

25

Type material: P. lemniscatus : holotype BMNH 1996404 . C. (C.) liltvedi : holotype SAM 35885 , 4 paratypes SAM 35886 (1 PV), 1 paratype NMSA D1615 /T3144 (1 PV), others in H. P. Wagner colln, no. 1000 (1 PV), W. R. Liltved colln (1 PV) and C. M. Connolly colln (1 LV) .

Regional data (selected records only): MOZAMBIQUE: SW Conducia Bay, NW Choca, washed ashore during cyclone (NMSA H4209: K. J. Grosch); same loc., 0.6 m, Thalassodendron and gravel, dead (NMSA H4208: K. J. Grosch); same loc., LST, Thalassodendron , gravel (NMSA H210: K. J. Grosch); Bazaruto Island (NMSA F5305: J. Dichmont); Bazaruto Island (NMSA J5092); off Inhambane, byssally attached to coral, live (HD6719); Inhaca Is. (NMSA 4476, 9888: P. Boshoff); off Malongane, 5–10 m N of Ponta do Ouro, coral reef, 15–20 m, dead (NMSA L1321: D. Herbert). SOUTH AFRICA (all NMSA): Zululand: between Bhanga Neck and Kosi Bay, reef off marker 13 N, 9–14 m, dead (S1598: D. Herbert et al.); same loc., No. 13 reef, 6–18 m, live (D9592: D. Herbert et al.); off Kosi Bay, 51 m, sand, stones, large algae, dead (S8958: NMDP); same data, 45 m, sand, stones, dead (S4864); Kosi Bay, main reef, 1–4 km S of estuary mouth, 16–20 m, dead (S1390: D. Herbert et al.); same loc., 18–22 m, 21–24, 21–24 m and 10–16 m, dead (S1006, S1834, S1942: D. Herbert et al.); same loc., 17–18 m, live (S1110: D. Herbert et al.); SE of Kosi Bay, 50 m, algae, shells, live (D6097: NMDP); off Boteler Point, 50 m, dead coral rubble, live (D7341: NMDP); same data, coral and sponge. living (D6843: NMDP); NE of Dog Point, 56–57 m, sand, lithothamnial pebbles, dead (S5039: NMDP). Sodwana Bay,Two-Mile Reef, 10–15 m, sorted from stone washings, live (E755:D. Herbert & R. Broker); same loc., inner edge, 14–15 m, live (D4990: D. Herbert); same loc., outer edge, 14–17 m, dead (D5094: D. Herbert); Sodwana Bay, Seven-Mile Reef, 20–23 m, dead (S3349: D. Herbert); Ledsman Shoal, reef off wreck of Tamavo, 20–28 m, dead (E2418: D. Herbert & KZNW); same loc., outer portion, 24–26 m, sorted from stone washings, live (E2600: D. Herbert & KZNW); same loc., Raggie Reef, 1–2 km N of Leven Point, 8–12 m, a mixed algal and coral reef, dead (E2468: D. Herbert & KZNW). Natal: Durban (2416: H. C. Burnup); Durban (4474, 2415: H.. C. Burnup); Aliwal Shoal, on inside of reef, just S of the Pinnacles, among boulders, 10 m, dead (B2896: D. Smith); Aliwal Shoal, off Scottburgh, 10–20 m, dead (S8036: D. Herbert).

Distribution: Western Indian Ocean, from Malagasy Republic and the Mascarenes to eastern South Africa, as far south as southern Natal.

Habitat:Living byssally attached to rocks or corals and between coral rubble or sediments on sandy or muddy sand bottoms at littoral to sublittoral depths.

Remarks: C. liltvedi is here synonymised with Pecten lemniscatus , as it agrees in all aspects with the holotype of that. The most similar species is Laevichlamys rubromaculata (G. B. Sowerby 2nd, 1842) from the NW Indian Ocean and Red Sea. This differs from L. lemniscata mainly in its more delicate and weaker sculpture and microsculpture, and in its coloration of red, orange or brown maculations between primary radial ribs on a creamy or yellow background (it is rarely uniformly coloured). In the literature the name ‘ P. lemniscatus ’ has been frequently misapplied; thus, records under this name by Dautzenberg & Bavay (1912: 13), Kira (1962: 137), Habe (1981: 63), Abbott & Dance (1982: 312), Rombouts (1991: 15) and Bernard et al. (1993: 48) were based on various Scaeochlamys species. Smith’s (1885: 298) record of ‘ Pecten lemniscatus ’ from the Philippines is also doubtful, as material from that region has a shagreened microsculpture, which is absent in the holotype of P. lemniscatus , and is in fact lacking in this species throughout its ontogeny.

Figures

Figs. 25–26. Laevichlamys lemniscata (Reeve, 1853): NMSA S8958, off Kosi Bay, Zululand, 51 m, pv, 48.6 x 44.1 mm. 25. LV exterior. 26. RV exterior.