Gloripallium pallium ( Linnaeus, 1758 )

Dijkstra, H. H. & Kilburn, R. N., 2001, The family Pectinidae in South Africa and Mozambique (Mollusca: Bivalvia: Pectinoidea), African Invertebrates 42, pp. 263-321 : 280-281

Gloripallium pallium ( Linnaeus, 1758)

Ostrea pallium Linnaeus, 1758: 697 , no. 163; Dijkstra, 1999: 405, figs 2 E–F, 3 A–B (lectotype). Type locality: ‘O. australiore & Indico’ [= Moluccas (Maluku), Indonesia, designated Dijkstra, 1999]. Chlamys (Aequipecten) pallium ; Cox, 1927: 48, 75, pl. 3, fig. 5, pl. 16, fig. 5; idem, 1929: 123, 152, pl. 14, fig. 4; Eames & Cox, 1956: 18, 44.

Aequipecten pallium ; Lamy, 1935: 314.

Gloripallium pallium ; Dijkstra, 1984: 17, fig.; idem, 1989: 15, illustr.; idem, 1991: 46; idem, 1998: 21; Dijkstra et al., 1989: 24; 1990: 3; Rombouts, 1991: 42, pl. 15, figs 4–4a; Dijkstra & Knudsen, 1998: 63, pl. 10, figs 48–49 (further references, synonymy, type data, distribution, discussion). Cryptopecten pallium ; Abbott & Dance, 1982: 309, fig.

Pecten novaeguinae Tenison Woods, 1878: 267 . Type locality: Hall Sound , Papua New Guinea (Pleistocene). Pecten speciosus Reeve, 1853 : pl. 27, fig. 112. Type locality: Philippine Islands .

Pecten (Aequipecten) pallium var. speciosa [sic]; Dautzenberg & Bavay, 1912: 20.

Chlamys (Aequipecten) pallium var. speciosa [sic]; Lamy, 1935: 314.

Gloripallium speciosum ; Habe, 1981: 66; Rombouts, 1991: 43, pl. 15, figs 8, 8a–c.

Cryptopecten speciosum [sic]; Abbott & Dance, 1982: 309, fig.

Gloripallium pallium forma speciosum ; Dijkstra, 1988: 19, fig.; idem, 1991: 46.

Description: Shell up to 90 mm high, usually ca. 60 mm, equivalve, equilateral, orbicular, auricles unequal, umbonal angle ca. 90–95°. LV with 12–15 primary radial costae, usually 13, and secondary radial riblets on costae (usually 3, absent near anterior and posterior margins) and in interspaces (2–4). Interspaces equal to/or broader than costae. Concentric lamellae on ribs in early growth stages, more tripartite near ventral margin. Auricles with 3–6 squamous or nodulous radial ribs. RV with similar sculpture as LV. Radial costae somewhat broader than on LV. Interspaces smaller than costae. Hinge line straight. Byssal fasciole rather wide, byssal notch deep. Active ctenolium with 3– 6 teeth on suture. Resilifer elongate and triangular. Marginal auricular gape present beneath auricular crura. Inner surface plicated. External colour extremely variable, vividly coloured with blotches and/or bands of red, yellow, purple, maroon or brown; interior whitish, with orange or purple near margins and on auricles.

Type material: O. pallium : lectotype designated Dijkstra (1999) in LSL, paralectotypes in LSL and MSNP. P. novaeguinae : not traced [Mrs L. Turner, Dr N. Kemp (TMAG) pers. comm.]. P. speciosus : holotype BMNH 1950.11.14.67; seen by HD.

Regional data: G. pallium : MOZAMBIQUE: Conducia Bay (NMSA H 4468: K. J. Grosch), typical form. SOUTH AFRICA: Zululand (all NMSA: NMDP, form speciosum ): SE of Rocktail Bay, 60 m, coarse sand, dead (S5267); off Lala Nek, 74 m, shells, sand, dead (S7398); same loc., 75 m, coarse sand, sandstone, coral, dead (S5783); same loc., 72 m, slightly muddy sand, pennatulids, dead (S7313).

Distribution: Throughout the tropical Indo-Pacific (except Red Sea and Hawaii), south-western limit northern Zululand.

Habitat: Living byssally attached to rocks or corals, or between coral rubble on sandy bottoms in shallow waters.

Remarks: Waller (1972: 241) considered Pecten speciosus Reeve, 1853 , to be a junior synonym (an ‘intrapopulation variant’) of G. pallium . However, populations of P. speciosus usually live in deeper water - down to sublittoral depths - and thus should rather be regarded as a bathymetric form. G. pallium form speciosum differs from typical G. pallium mainly in possessing more strongly developed concentric lamellae on its radial costae, which are not trifidly divided, and in lacking secondary radial riblets. Intermediate states between the two bathymorphs have been examined (collections MNHN and HD).

Gloripallium spiniferum (G. B. Sowerby 1st, 1835) from French Polynesia is similar to G. pallium form speciosum , but is smaller (less than ca. 30 mm high), less convex, has fewer (8–9) radial costae, and its auricles are more weakly sculptured to nearly smooth. The endemic Red Sea Gloripallium maculosum ( Forsskål, 1775) (syn. Ostrea sanguinolenta Gmelin, 1791 ) differs from G. pallium in its smaller size (up to ca. 50 mm) and more elongate form (umbonal angle ca. 85–90°); furthermore maculosum has more prominent radial costae, which are fewer (7–9) in number and bear more numerous (6–9) secondary radial riblets; concentric lamellae are also more closely spaced than in G. pallium .

The present material from Mozambique is similar to the type material of G. pallium . South African specimens of G. pallium form speciosum resemble the type material of the latter, although on the LV the rib intervals are slightly broader and coloration is paler. This is a new record for South Africa.