Ctena bella ( Conrad, 1837 )

Raines, Bret & Huber, Markus, 2012, 3217, Zootaxa 3217, pp. 1-106 : 48-49

Ctena bella ( Conrad, 1837)

Figures 24 A–D

Lucina bella Conrad, 1837: p. 254 , pl. 19, fig. 11.

Ctena bella ( Conrad, 1837) — Dall et al., 1938: p. 129, pl. 35, figs. 1–8; Kay, 1979: p. 543, figs. 176 A–D; Preece, 1995: p. 350; Tröndlé & Boutet, 2009: p. 7; Severns, 2011: p. 468, pl. 214, fig. 2.

Codakia (Epicodakia) bella ( Conrad, 1837) — Rehder, 1980: p. 110.

Ctena bella (Conrad, [sic] 1834)— Brook & Marshall, 1998: p. 212; Spencer et al., 2011: p. 1.

Epicodakia bella ( Conrad, 1837) — Okutani, 2000: p. 929, pl. 462, fig. 5.

Material examined. Several hundred articulated specimens and single valves from EI and SyG (BK), plus specimens from the Hawaiian Islands ( MHU), Marquesas Islands ( MHU), Australia ( MHU) and Pitcairn Island (BK).

Diagnosis. Shell small (up to 20 mm in length) broadly ovate to suborbicular shape, equivalve, inequilateral, not fragile. Umbones somewhat elevated; lunule moderately impressed and elongate. Exterior surface of rounded radiating ribs crossed by commarginal ridges forming low elongate nodules on the ribs. Interior muscle scars unequal, with pallial sinus running nearly continuous; margin crenulate. Hinge with two cardinals, which are bifid in the right posterior and left anterior, and opposing laterals in each valve. Color creamy white to pale yellow.

Remarks. The EI specimens conform well to the Hawaiian material. Dall et al. (1938) corrected the erroneous original type locality for C. bella from San Diego to the Hawaiian Islands. The Hawaiian species was accepted by J. Taylor, (pers. comm., 2010) to represent bella . The Japanese Ctena delicatula ( Pilsbry, 1904) , is a similar, but a morphologically distinct species and most noticeable in adult valves by having finer radial ribs and fewer commarginal ridges.

Habitat. Commonly found at many locations around EI and SyG, in sand and rubble, from 10–50 m.

Distribution. Ctena bella is widely distributed throughout the Indo-Pacific, ranging from the Hawaiian Islands to the Kermadec Islands to include the Society Islands, Marquesas Islands, Tuamotu Archipelago, Gambier Islands, Austral Islands, eastern Australia, Norfolk Island, and Pitcairn Islands, as well as Easter and Salas y Gómez Islands— E5.