Calliotropis velata Vilvens, 2006

Herbert, David G., 2024, The Vetigastropoda (Mollusca) of Walters Shoal, with descriptions of two new genera and thirty new species, European Journal of Taxonomy 923, pp. 1-119 : 27

Calliotropis velata Vilvens, 2006

Figs 13D–F , 14A–B

Calliotropis velata Vilvens, 2006: 57 , figs 1–7.

Type loc.: off north-western Madagascar, 15°18.3′ S, 46°10.3′ E [off Mahajanga], depth 500– 550 m .

Calliotropis sp. 2 . cfr. concavospira ( Schepman, 1908) – Nolf & Verstraeten 2003: 16, text-fig.

Calliotropis velata – Vilvens 2021: 102, fig. 4a–h.

Material examined

MADAGASCAR • 1 empty shell; SW of Nosy Be ; 13.833°S, 47.617°E; depth 850–1125 m; Feb. 1975; ORSTOM leg.; dredged; NMSA J1961 • 1 empty shell; off Toliara; depth 400–800 m; Jan. 2001; W. Massier don.; trawled; NMSA L5555 .

WALTERS SHOAL – slopes • 1 empty shell; stn CP4905; 33°32′ S, 44°00′ E; depth 1000–1052 m; 9 May 2017; MNHN • 1 living specimen; stn CP4910; 32°5′ S, 44°06′ E; depth 986–988 m; 10 May 2017; DNA tissue sample; MNHN-IM-2013-67242 • 1 living specimen; stn CP4910; 32°5′ S, 44°06′ E; depth 986–988 m; 10 May 2017; DNA tissue sample; MNHN-IM-2013-67243 • 1 empty shell; stn CP4910; 32°5′ S, 44°06′ E; depth 986– 988 m; 10 May 2017; MNHN • 6 empty shells; stn CP4911; 32°46′ S, 44°18′ E; depth 964–965 m; 10 May 2017; MNHN • 4 specimens, some living; stn CP4912; 32°49′ S, 44°23′ E; depth 961–966 m; 10 May 2017; MNHN .

Distribution

West coast of Madagascar, from the Nosy Be area south to the Taolagnaro (Fort Dauphin) region, at depths of 425–986 m and the east coast of Mozambique ( Vilvens 2021); extending south to Walters Shoal where it has been trawled on the surrounding slopes at depths of 965–1000 m (live-taken material 966–986 m), on substrata of coarse sand, solitary coral rubble and pteropod shell debris, with diverse sponges, cnidarians, decapods and echinoids.

Remarks

Specimens from Walters Shoal typically have four spiral cords on the base, the strength of the beading of which varies between individuals. The innermost basal cord, which is usually the most coarsely beaded, and also often the strongest, may occasionally be duplex. The observation of Vilvens (2006) regarding the absence of a correlation between specimen size and the closure of the umbilicus by the overarching septum applies equally to material from Walters Shoal.

The shell microsculpture is typical of Calliotropis , comprising well-defined, tightly packed, slash-like marks ( Fig. 14A ). The protoconch is large and globose, strongly exsert, comprising approx. 1.25 whorls, diameter 500–510 μm ( Fig. 14B ); apex rounded, terminal lip very slightly convex, not thickened; surface smooth, no superficial microsculpture evident.

Figures

Fig. 13. A–C. Calliotropis eucheloides Marshall, 1979. A. Apertural view showing duplex tooth at base of columella, Walters Shoal, stn DW4904, diameter 12.0 mm (MNHN-IM-2013-67241). B–C. Apical and basal views, Walters Shoal, stn DW4892, diameter 10.6 mm (MNHN). D–F. Calliotropis velata Vilvens, 2006, Walters Shoal, stn CP4910, diameter 15.9 mm (MNHN-IM-2013-67242). G. Calliotropis eucheloides, living animal, shell diameter 12.2 mm (MNHN-IM-2013-67240), image courtesy of Alain Barrère/MNHN. H–J. Spinicalliotropis lepidota sp. nov., holotype, height 2.9 mm (MNHN- IM-2000-36293).

Fig. 14. A–B. Calliotropis velata Vilvens, 2006, Walters Shoal, stn CP4911 (MNHN), scale bars =200 μm. A. Microsculpture, third whorl. B. Protoconch. C. Danilia textilis Herbert, 2012, Walters Shoal, stn DW4887, height 11.7 mm (MNHN-IM-2013-67256). D–E. Vaceuchelus gemmula (Turton, 1932), Walters Shoal, stnWB05, height 3.4 mm (MNHN-IM-2013-67254).F–H. Vetulonia parajeffreysi Absalão & Pimenta, 2005, Walters Shoal, stn CP4913, diameter 2.5 mm (MNHN). I. Vetulonia parajeffreysi, protoconch, Walters Shoal, stn CP4913, scale bar =100 μm (MNHN).