Siphonaria maloensis sp. nov.

(Figs 63C–F)

Material examined. Type material. Holotype, from N coast of Malo Is, 15°37.7’S, 167°11’E, Vanuatu; coll. Marine Biodiversity Survey, 18 Sept. 2006 VM16, sand and coral (MNHN IM-2006-31454 p [M545] Fig. 63C) . Paratype, same data as holotype (MNHN IM-2006- 31358 p [M546], Fig. 63D); two paratypes, from Palikulo Peninsula, 15°28.8’S, 167°15.3’E, Vanuatu; coll. Marine Biodiversity Survey, 14 Sept. 2006 VM11, hard bottom (MNHN IM-2006-31355 p [M547], Fig. 63E; IM-2006- 31353 p [M548], Fig. 63F) .

External morphology (preserved). Foot sole, foot wall, cephalic folds and pneumostome cream, paler to foot edge; mantle translucent, edge thickened strongly lobed with dark/black pigmentation on mantle edge aligning with rib interstices, faint pigmentation over cephalic folds.

Shell (Figs 63C–F; Table S9). Ovate, small to medium sized (max sl mean = 17.9 mm, SD = 2.3 mm, n = 4); apex offset central and weakly to left, apical sides strongly convex, height tall; protoconch direction undetermined, shell whorl dextral; exterior uneven without prominent radial colour bands; growth striae distinct, shell thickness thick; rib count (mean = 45.5, SD = 2.3, n = 4), ribs fairly even, primary ribs pale grey, wavy, slightly broaden and increasingly raised to shell edge, ridges rounded narrow; edge finely scalloped and unevenly corrugated; siphonal ridge clear, formed by 2–3 primary ribs; few finer secondary ribs, rib interstices darker grey with irregular red/brown markings; interior shell margin white, red brown rays aligned under rib interstices, from shell lip over shell margin to spatula, siphonal groove distinct, same colour as shell margin; spatula dark brown; ADM scar distinct, darker brown, CMS convex; thickening and whitening of shell lip occurs (Fig. 63C).

Comparative remarks. In our molecular phylogeny (Figs 1, 2), S. maloensis sp. nov. ( laciniosa group, unit 87) is the sister species of S. caledonica sp. nov. (unit 23) from New Caledonia. Both species differ from each other by 16S distances of ≥ 9.7%. Siphonaria maloensis differs from S. normalis by 16S distances of ≥ 10%. Morphologically, S. caledonica sp. nov. has a smaller, thinner, taller, darker shell, with more prominent primary ribbing, and a less scalloped edge. We found S. maloensis sp. nov. in sympatry with S. viridis in Vanuatu; refer to comparative remarks under that species.

Distribution and habitat. Recorded exclusively from Malo Island, Vanuatu, Pacific Ocean (Fig. 67). In this study, found on hard substrate, sand and coral, intertidal.

Etymology. Named after the type locality of Malo Island, Vanuatu, Pacific Ocean.