Neopycnodonte cochlear ( Poli, 1795 )

Raines, Bret & Huber, Markus, 2012, 3217, Zootaxa 3217, pp. 1-106 : 28

Neopycnodonte cochlear ( Poli, 1795)

Figures 13 A–B

Ostrea cochlear Poli, 1795: p. 179 , pl. 28, fig. 28.

Ostrea laysana Dall et al., 1938: p. 111 , pl. 32, figs. 5–8.

Ostrea laysana Dall et al., 1938 — Kay, 1979: p. 538.

Neopycnodonte cochlear ( Poli, 1795) — Oliver, 1992: p. 89, pl. 16; Huber, 2010: p. 185, fig. 8; Severns, 2011: p. 464, pl. 212, fig. 3.

Material examined. Single very juvenile upper valve (6.2 mm) from EI (BK), plus specimens from the Hawaiian Islands ( MHU).

Diagnosis. Shell small to medium, suboval to subcircular, inequivalve, inequilateral, somewhat fragile. Upper valve flat and much smaller than the concave lower cemented valve. Exterior surface of commarginal ridges and irregular laminar layers. Interior margin typically with vermicular chomata on both sides of the resilifer. Color variable, buff to yellowish green.

Remarks. Although quite small, this single upper valve matches in texture, muscle scar, chomata and hinge very well. It is expected that deep water trawls will provide additional and larger material given the species prefers deeper water.

Habitat. Found at 100 m at Ovahi, EI.

Distribution. This deep water species is widely distributed. Although originally described from Sicily, Italy, Neopycnodonte cochlear is also known from the Red Sea, eastern Africa, Japan, the Hawaiian Islands and Australia. However, it has never been recorded from western America, New Zealand, or the Kermadec Islands. Easter Island is now considered a range extension— E5.