Amalda hilgendorfi
Creators: name: Kantor, Yuri I.
name: Castelin, Magalie
name: Fedosov, Alexander
name: Bouchet, Philippe
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Neogastropoda
Olividae
Amalda
Amalda hilgendorfi

description: Southern New Caledonia morph (“ pupiform ”)
Figs 2 (as sNC), 6, 7F
Material examined
Sequenced material
26 sequenced specimens (all MNHN) (Table 1).
Not sequenced material
SOUTHERN NEW CALEDONIA • Material listed by Kilburn & Bouchet (1988) • 1 dd; Île des Pins; 22°48′ S, 167°15′ E; 440–470 m deep; TERRASSES; stn CP3115 • 1 dd; SW of Île des Pins; 22°54′ S, 167°17′ E; 496–505 m deep; KANACONO; stn DW4722 • 2 dd; W of Île des Pins; 22°50′ S, 167°16′ S; 480–505 m deep; VAUBAN 1978–1979; stn DR23 • 5 lv, 1 dd, S of Île des Pins; 22°53′ S, 167°17′ E; 570–610 m deep; BIOCAL; stn DW 46 • 1 dd; S of Grande Terre; 22°56′ S, 167°17′ E; 485–520 m deep; MUSORSTOM 4; stn CP215 • 1 dd; S of Grande Terre; 22°56′ S, 167°17′ E; 485–520 m deep; MUSORSTOM 4; stn DW223 • 2 worn dd; 22°51′ S, 167°13′ E; 445–460 m deep; MUSORSTOM 4; stn DW229 • 2 dd; S of Île des Pins; 22°52′ S, 167°13′ E; 415 m deep; SMIB 1; stn DW02 • 7 dd; S of Île des Pins; 22°55′ S, 167°16′ E; 490–495 m deep; SMIB 2; stn DW10 • 1 dd; Banc Éponge; 24°54′ S, 168°22′ E; 530 m deep; SMIB 3; stn CP04; • 1 worn dd; Kaimon Maru Bank; 24°45′ S, 168°08′ E; 233 m deep; SMIB 3; stn DW08 • 1 lv; SW of Île des Pins; 22°59′ S, 167°19′ E; 525 m deep; SMIB 3; stn DW21 • 1 lv, 1 dd; SW of Île des Pins; 23°03′ S, 167°19′ E; 503 m deep; SMIB 3; stn DW22.
Remarks
A very peculiar morph with medium-sized shell (SL up to 53.7 mm, usually less than 35 mm), occurring only in southern New Caledonia, mostly off Île des Pins, with a few specimens collected on Norfolk Ridge. Despite morphological similarity between specimens, these are genetically heterogeneous, belonging to different highly divergent assemblagies of haplotypes (marked by yellow in Fig. 3), some being closer to specimens from northern New Caledonia and the Coral Sea, while others constituting a subclade on the tree (Fig. 2). In total eight haplotypes were identified within this morph.
Shell shape pupiform due to very strong development of primary and secondary calluses on upper teleoconch whorls, while uppermost 2.5–3 whorls (including those of protoconch) remain uncovered, revealing the papillate apex. Except the large development of the callus, the shell shape is rather similar to those in the north New Caledonia morph and some specimens with less developed callus (e.g., MNHN IM-2013-69558 or MNHN IM-2007-43673 on Fig. 6C) are practically indistinguishable (e.g., MNHN IM-2009-11918, Fig. 5I). Columellar ridges rather distinct, 6–7. Upper anterior band usually evenly convex, not subdivided by a ridge. First protoconch whorl diameter 0.84–0.90 mm (mean 0.86, n= 5). Depth range 233– 610 m.
On Norfolk Ridge and off southern New Caledonia, some specimens very similar to those from north of New Caledonia were found in deeper water in 560–650 m in addition to the pupiform morph. One specimen was collected on Banc Eponge (Fig. 6I) in a haul with a very large depth range, 564–1144 m, but the deepest record needs confirmation. Although none of these specimens were sequenced, there is no doubt of their identity.
description: Published as part of Kantor, Yuri I., Castelin, Magalie, Fedosov, Alexander & Bouchet, Philippe, 2020, The Indo-Pacific Amalda (Neogastropoda, Olivoidea, Ancillariidae) revisited with molecular data, with special emphasis on New Caledonia, pp. 1-59 in European Journal of Taxonomy 706 on pages 21-23, DOI: 10.5852/ejt.2020.706, http://zenodo.org/record/4010954