Anodontia (Pegophysema) philippiana ( Reeve, 1850 )

Glover, Emily A. & Taylor, John D., 2007, Diversity of chemosymbiotic bivalves on coral reefs: Lucinidae (Mollusca, Bivalvia) of New Caledonia and Lifou, Zoosystema 29 (1), pp. 109-181 : 112-114

Anodontia (Pegophysema) philippiana ( Reeve, 1850)

( Figs 2A, B ; 3A )

Lucina philippiana Reeve, 1850 : pl. 5, fig. 23a, b.

Anodontia philippiana – Chavan 1938: 124.

TYPE MATERIAL. — 3 syntypes ( BMNH 1963122/123).

TYPE LOCALITY. — Unknown.

MATERIAL EXAMINED. — Touho. 3 stn, 0-4 m, 2 v, 1 live.

Other New Caledonia. Hienghène, mission d’Ouavé, 20°41’S, 164°56’E, intertidal, 20 v.

DISTRIBUTION. — Wide ranging across the IWP, from Red Sea and East Africa, through south east Asia and northern Australia to New Caledonia and Palau Islands ( Taylor & Glover 2005: fig. 22). Usually lives deeply burrowed (up to 50 cm deep) in intertidal and shallow subtidal muds and sands along the seaward fringe of mangroves.

DESCRIPTION

Shell large but thin and light-weight, H to 60.0 mm, L to 71.0 mm, inflated (T/L 0.30). Outline

dpl

G

subcircular, shell longer than high (H/L 0.89). Periostracum thick, dull brown, fibrous. Shell colour creamy or greyish white.Sculpture of many irregular, rounded, commarginal lamellae or ridges. Lunule short, heart-shaped, symmetrical. Hinge plate thin, edentulous and smooth. Ligament largely internal; inner fibrous layer of ligament extends laterally and posteriorly into the valve forming a thick, triangular pad within narrow ligamental nymph. Anterior adductor muscle scar relatively broad and short, blunt ended; diverges from pallial line at an angle of 30-34°. Pallial line entire, narrow. Secondary pallial muscle scars extend from the junction of the pallial line and anterior adductor scar to just ventral of the posterior adductor scar ( Fig. 3A ).

REMARKS This is the largest of the Anodontia species from New Caledonia. Often referred to as Anodontia edentula in literature (e.g., Sotto & Cosel 1982; Lebata 2000).

Figures

FIG. 2. — A, B, Anodontia (Pegophysema) philippiana (Reeve, 1850), New Caledonia (BMNH 1963143/2), exterior and interior of right valve; C, D, A. (Euanodontia) ovum (Reeve, 1850), stn 1406, Lifou, Loyalty Islands, interior and exterior of left valve (MNHN); E, F, A. (Cryptophysema) vesicula (Gould,1850),Ouvéa,Loyalty Islands,exterior and interior of right valve (MNHN);G, H, A.(Euanodontia) hawaiensis (Dall, Bartsch & Rehder, 1938), stn 1418, Lifou, Loyalty Islands (MNHN), exterior and interior of right valve. Abbreviation: dpl, divided pallial line. Scale bars: 10 mm.

FIG. 3. — Outline drawings of interiors of right valves of Anodontia Link, 1807 and Leucosphaera Taylor & Glover, 2005 species: A, A. (Pegophysema) philippiana (Reeve, 1850);B, A. (Euanodontia) ovum (Reeve,1850); C, A. (E.) hawaiensis (Dall,Bartsch & Rehder, 1938); D, A. (Cryptophysema) vesicula (Gould, 1850); E, L. diaphana n. sp. Not to scale.