Siphonaria maloensis, B. W. Jenkins & Köhler, 2024

Jenkins, Bruce & Köhler, Frank, 2024, Hidden in plain sight: Systematic review of Indo-West Pacific Siphonariidae uncovers extensive cryptic diversity based on comparative morphology and mitochondrial phylogenetics (Mollusca, Gastropoda), Megataxa 13 (1), pp. 1-217 : 162

publication ID	https://doi.org/10.11646/megataxa.13.1.1
DOI	https://doi.org/10.5281/zenodo.14983751
persistent identifier	https://treatment.plazi.org/id/0D49832F-FF3C-82BD-FF68-FE22FE6AF7D6
treatment provided by	Plazi (2025-03-05 09:04:49, last updated 2025-03-07 14:54:03)
scientific name	Siphonaria maloensis
status	sp. nov.

Treatment

Siphonaria maloensis View in CoL sp. nov.

( Figs 63C–F View FIGURE 63 )

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 View FIGURE 63 ) GoogleMaps . Paratype, same data as holotype ( MNHN IM-2006- 31358 p [M546], Fig. 63D View FIGURE 63 ); GoogleMaps 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 View FIGURE 63 ; IM-2006- 31353 p [M548], Fig. 63F View FIGURE 63 ) GoogleMaps .

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 View FIGURE 63 ; 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 View FIGURE 63 ).

Comparative remarks. In our molecular phylogeny ( Figs 1 View FIGURE 1 , 2 View FIGURE 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 View FIGURE 67 ). In this study, found on hard substrate, sand and coral, intertidal.

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

Figures

FIGURE 1. Maximum Likelihood phylogram based on analyses of a concatenated sequence data set of 16S and COI. Branches are collapsed at the species level. Branch labels give unit numbers and accepted species names. Numbers on branches indicate branch support employing 10,000 ultrafast bootstraps.Available genus-group names are shown next to their type species. Scale bar indicating modelled sequence divergence.

FIGURE 2. Maximum Likelihood phylogram (partial, species not collapsed). Clades G–I (atra group) of the tree shown in Fig. 1. Branch labels give specimen identifiers for new sequences or Genbank accession numbers for imported sequences from other studies and geographic regions (seeTables S1–S2 for details). Identical haplotypes are merged into single tips. Numbers on branches indicate branch support by employing 10,000 ultrafast bootstraps. Clade names give unit numbers and accepted species names. Scale bar indicating modelled sequence divergence. Figure spread over two pages.

FIGURE 63. Shells of S. madangensis sp. nov., S. maloensis sp. nov., S. mauiensis sp. nov., S. nusalikensis sp. nov. and S. cacao sp. nov. A–B. S. madangensis sp. nov. A. Holotype MNHN IM-2013-12006 [M550]. B. Paratype IM-2013-13132 [M552]. C–F. S. maloensis sp. nov. C. Holotype IM-2007-31454 [M545]. D. Paratype IM-2007-31358 [M546], Sek Is. E. Paratype IM-2007- 31355 [M547], Palikulo Peninsula. F. Paratype IM-2007-31353 [M548], Palikulo Peninsula. G–K. S. mauiensis sp. nov., Maui, Hanakao’o Beach. G. Holotype AM C.584888 [M297, SK208]. H. Paratype AM C.584891 [SK207]. I. Paratype AM C.584890 [SK245]. J. Animal. K. In situ. L. Holotype of S. nusalikensis sp. nov. IM-2013-55334 [M532]. M–O. S. cacao sp. nov., French Polynesia, Tubuai. M. Holotype IM-2007-35319 [SK506]. N–O. Paratypes IM-2007-35317/18. Unlabelled scale bars = 10 mm.

FIGURE 67. Known occurrence records of S. madangensis sp. nov., S.maloensis sp.nov., S. mauiensis sp. nov., S.namukaensis sp. nov., S. nusalikensis sp. nov. and S. cacao sp. nov.