Amalda contusa ( Reeve, 1864 )

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 : 51-52

Amalda contusa ( Reeve, 1864)

Figs 19 C–D, 20C–D

Ancillaria contusa Reeve, 1864 : pl. 9, species no. 31.

Amalda contusa – Gratecap 2012: 19, 27, figs 1–2 (holotype illustrated), 3–5.

Amalda cf. contusa – Gratecap 2012: figs 9–10.

Type Material

Holotype

Holotype by monotypy; locality unknown; NHMUK 197836 .

Material examined

Three sequenced specimens ( Table 1).

Description

MEASUREMENTS. Shell small (SL up to 25 mm).

SHELL. Broadly ovate, with narrow base and low conical spire. Primary spire callus very thick, smooth and glossy, covering all whorls, except tip of protoconch, rendering measurements impossible. Secondary callus rather thick, with distinct anterior border, smooth and glossy, fusing without visible border with parietal callus, and reaching shell apex. Plication plate smooth, separated from anterior band by broad and deep groove, columella smooth. Olivoid groove shallow but distinct, labral denticle short, obtuse. Anterior band smooth, upper and lower anterior bands weakly convex. Primary callus milky-caramel with irregularly positioned sinuous, brownish axial lines, abapically bordered by interrupted narrow spiral, brown and lighter narrow lines. Secondary callus dark brown, turning very light above aperture. Body whorl cloak background caramel with irregularly spaced, orthocline, brown axial bands of uneven width and lighter spiral colour lines, olivoid band much lighter than cloak, of same tint, anterior band very dark brown, light brown near columella, very light brownish abapically.

RADULA (n =1, sequenced, Fig. 20 C–D). With rather short, hook-shaped lateral teeth. Central tooth broad, with broad lateral flaps, and three major cusps, median more than twice shorter and narrower than lateral ones. Lateral cusps serrated at their base as well as lateral flaps. 1–4 additional, smaller, irregularly shaped cusps between median and lateral major cusps.

Remarks

Our sequenced specimens correspond to what was treated and illustrated by Gratecap (2012: figs 9–10) as A. cf. contusa . This author also provided a lengthy discussion of the complex taxonomic history of A. contusa and concluded that there may be two similar but separate species, one in Natal, and the other in Mozambique and Natal. At present, the lack of comparative material does not allow us to clarify the situation and we provisionally consider our specimens to be the true A. contusa .

Distribution

KwaZulu Natal and Mozambique, in 15– 20 m.

Figures

Fig. 19. Sequenced species of Amalda H. Adams & A. Adams, 1853. A–B. Amalda sp., MNHN IM- 2013-63891, SL 20 mm. C–D. A. contusa (Reeve, 1864), MNHN IM-2009-22263, SL 24.9 mm. E. A. optima (G.B. Sowerby III, 1897), MNHN IM-2007-38287. F–G. A. monilifera (Reeve, 1864), MNHN IM-2013-63898, SL 11.7 mm. H–I. A. hinomotoensis (Yokoyama, 1922), MNHN IM-2019-618, SL41.4 mm.J–K.A.hayashii Ninomiya, 1988, MNHNIM-2013-44413,SL38.4 mm.L–M.A.bellonarum Kilburn & Bouchet, 1988, MNHN IM-2007-33273. Shells not to scale.

Fig. 20. Radulae of species of Amalda H. Adams & A. Adams, 1853. A. Amalda sp., MNHN IM-2013- 63891 (shell on Fig. 19A–B). B, E. A. monilifera (Reeve, 1864), MNHN IM-2013-63898 (shell on Fig. 19F–G). C–D. A. contusa, MNHN IM-2009-22264, SL 22.7 mm. F–I. A. hayashii Ninomiya, 1988. F–G. MNHN IM-2013-44413 (shell on Fig. 19J–K). H. MNHN IM-2013-44432. I. MNHN IM-2013- 44457, SL 38.2 mm. J–K. A. hinomotoensis (Yokoyama, 1922), MNHN IM-2019-619, SL 38.5 mm.