Lasaea hawaiensis Dall, Bartsch & Rehder, 1938

Raines, Bret & Huber, Markus, 2012, 3217, Zootaxa 3217, pp. 1-106 : 50-51

Lasaea hawaiensis Dall, Bartsch & Rehder, 1938

Figures 25 A–D

Lasaea hawaiensis Dall et al., 1938: p. 141 , pl. 38, figs. 1–4, text fig. 18.

Lasaea hawaiensis Dall et al., 1938 — Kay, 1979: p. 547, figs. 178 A & 179 A; Rehder, 1980: p. 111, pl. 14, figs. 7–9; Tröndlé & Boutet, 2009: p. 8; Severns, 2011: p. 470, pl. 215, fig. 5, non fig 4.

Material examined. Over one hundred live taken specimens and single valves from EI and SyG (BK), plus specimens from the Hawaiian Islands ( MHU) and Pitcairn Island (BK).

Diagnosis. Shell large for the genus (up to 6 mm in length), suborbicular to broadly ovate, inflated, and not fragile. Umbones elevated. Exterior surface of commarginal growth lines and dense punctate microsculpture. Pallial line continuous; margins smooth. Hinge stout, consisting of broad lateral teeth. Color variable only in intensity, translucent white and tinged with reddish purple which is darker toward the umbones, and the posterior and anterior ends. Hinge and dorsal margin are usually stained as well.

Remarks. This species is similar in shape and color to the moderately smaller L. hinemoa Finlay, 1928 , from New Zealand and the much smaller European type species L. rubra ( Montagu, 1803) . The genus Lasaea has been a subject of great interest for the last twenty-five years. This near-cosmopolitan genus has the ability to brood their young either to a planktotrophic veliger or a crawl-away juvenile stage of development (Ó Foighil, 1989: 349). Furthermore, it challenges our preconception regarding planktotrophic species distribution. Several genetic studies on this genus indicate that Lasaea species with crawl-away juvenile stages actually have a greater geographic range than those with planktotrophic larvae. This is especially true among oceanic island groups. However, over time these non-planktotrophic genetic clones tend to become morphologically distinct (Ó Foighil 1986 & 1989; Taylor & Ó Foighil 2000; Ó Foighil et al. 2001).

Habitat. Commonly found at many locations around EI and SyG, in sand and rubble, from 5–80 m, living to around 20 m.

Distribution. Lasaea hawaiensis was originally described from the Hawaiian Islands, but is also known from the Marquesas Islands, Gambier Islands, Austral Islands, Pitcairn Islands, as well as Easter and Salas y Gómez Islands— E5.