Description of a new species of Calliostoma (Gastropoda, Vetigastropoda: Calliostomatidae) from the Cape Verde Islands

The Cancap expeditions explored the subtropical areas of the NE Atlantic Ocean between 1976 and 1986 (van der Land, 1987). Mollusca collected during these expeditions are retained in the systematic collection at Naturalis Biodiversity Centre (Nbc) in Leiden, the Netherlands. Groups of molluscs have already been reviewed: Polyplacophora (Kaas, 1991), Pectinidae (Dijkstra & Goud, 2002), Rissoidae (Hoenselaar & Goud, 1998), Pyramidellidae (van Aartsen et al., 1998, 2000), and Philinidae (van der Linden, 1995). Many families were only partly studied and undescribed species were left for future reviews. The second author currently reviews the gastropod families with many undetermined species. A new species of Calliostomatidae is described here. Species in Calliostomatidae live in all oceans from the littoral and shelf to bathyal depths. Most species are carnivorous (Hoffman et al., 2019), although littoral species may partially feed on algae (Fretter et al., 2019; de Bruyne et al., 2013). A significant inventory of NW African molluscs was completed by Locard (1897-1898) from the material collected during the Travailleur and Talisman expeditions; five species in the genus Calliostoma Swainson, 1840 were originally described in the genus Zizyphinus J. E. Gray, 1842. Recent reviews of the NE Atlantic / Azorean seamounts species of Calliostoma include Hoffman et al. (2019) and Gofas & Hoffman (2020). Juvenile specimens of an unidentified calliostomatid were reported by Rolán (2005) in his compilation of the molluscan fauna of the Cape Verde archipelago. Important reviews of fossil calliostomatids from the NE Atlantic include those by Millet (1865) on the Maine and Loire Basins and by Landau et al. (2017) on Upper Miocene species from NW France.