Amalda hilgendorfi, von Martens, 1897 (von Martens, 1897)

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, European Journal of Taxonomy 706, pp. 1-59 : 21-23

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.

Figures

Fig. 2. Molecular phylogeny of Amalda hilgendorfi (von Martens, 1897) produced by a Bayesian analysis of the Cox1 gene dataset. Outgroups and other species of Amalda have been removed from the tree. Only posterior probabilities ± 90% are shown. The unit for the scale is “substitutions/site”. The geographical distribution and morphological morphs are coded for each specimen: Phil =Philippines; Sol =Solomon Islands; PNG= Papua New Guinea; sNC = South New Caledonia; nNC = North New Caledonia; CS=Coral Sea. Numbers in parentheses at the tips of the tree link the MNHN IM voucher number to the corresponding photo on the right.

Fig. 3. Median-joining haplotype network based on Cox1 sequences of Amalda hilgendorfi (von Martens, 1897). Circles are colour coded by general location reported on the map and sized according to each haplotype’s relative abundance. Lengths of the lines connecting haplotype circles are proportional to the number of nucleotide differences among haplotypes. Green rectangle and oval encircle assemblages of haplotypes from New Caledonia (each including a specimen from Papua New Guinea).

Fig. 6. Amalda hilgendorfi (von Martens, 1897). Southern New Caledonia morph. A–D and E–H belong to two molecularly distinct subclades. A–B. MNHN IM-2007-43664, SL 30.6 mm. C. MNHN IM- 2007-43673, SL 34.2 mm. D. MNHN IM-2009-11964, SL 15.2 mm. E–F. MNHN IM-2007-43671, SL 33.8 mm. G. MNHN IM-2007-43674, SL 34.7 mm. H. MNHN IM-2009-11945, SL 31.6 mm. I. Norfolk Ridge, Banc Éponge, NORFOLK 1, stn DW 1693, 24°55′ S, 168°21′ E, 564–1144 m, SL 61 mm, specimen not sequenced, shell not to scale. Shells (except I, reduced) at the same scale.

Fig. 5. Amalda hilgendorfi (von Martens, 1897). A–F. Coral Sea morph. A-B. MNHN IM-2007- 33313, SL 66 mm. C. MNHN IM-2007-33289, SL 51.3 mm. D. MNHN IM-2007-33288, SL 60.3 mm. E. MNHN IM-2013-63901, SL 27-3 mm. F. MNHN IM-2007-33312, SL 25.9 mm. G–K. Northern New Caledonia morph = A. hilgendorfi richeri Kilburn & Bouchet, 1988. G. Holotype, MNHN IM-2000- 1378, SL 66.9 mm. H. MNHN IM-2009-11916, SL 65 mm. I. MNHN IM-2009-11918, SL 43.2 mm. J. MNHN IM-2007-42675, SL 48.7 mm. K. MNHN IM-2009-11966, SL 29 mm. Shells at the same scale.