Pacifica Fassio, Bouchet & Oliverio 2023, GEN. NOV

PACIFICA FASSIO, BOUCHET & OLIVERIO GEN. NOV. (FIGS 2, 3, 5A, B, 7C, D, 9E, F, 10G, H, 11G, H) Zoobank registration: urn: lsid: zoobank. org:act: BC75A004-F0A8-40C5-9636-2B3CFDC96EEF Type species: Pacifica lentiginosa Fassio, Bouchet & Oliverio sp. nov. Included species: Pacifica indecora (Bergh, 1886) comb. nov., Pacifica lentiginosa Fassio, Bouchet & Oliverio sp. nov. Description: Body of small size for the subfamily, 0.5– 1.0 cm total length. Shell very thin, weakly calcified; ear shaped, low spire, with expanded aperture; smooth or weakly sculptured by axial growth lines; completely enclosed by the mantle. Periostracum not visible. Protoconch of 1.6–1.8 whorls; nucleus diameter 110–135 μm; protoconch I 1.1–1.2 whorls, smooth, with subsutural axial folds; protoconch II with axial growth lines;protoconch–teleoconchboundarynotalwaysdistinct. Mantle flat or dome shaped, outline rounded; thin; with anterior siphon folds; texture smooth; colour almost transparent to white, grey, yellow, orange, pink, violet, brown, patterned with many small and big spots or colour patches. Penis to the right of the right cephalic tentacle; with a lateral subterminal papilla. Vas deferens with or without a free loop in haemocoel. Radula reduced taenioglossate, formula 0:1:1:1:0; rachidian tooth base bifurcated; rachidian cusp with three or four external long denticles on each side; lateral teeth elongated, with a pointed triangular external cusp, with four to seven long denticles on each side side. Jaws short, with an external protrusion on the upper side. Distribution: Indo-West Pacific (Madagascar, Philippines, Papua New Guinea, New Caledonia, Vanuatu); 20–244 m deep. Etymology: From the Latin adjective pacifica, meaning ‘peaceful’, as a symbolic quest for peace from the scientific community. Gender feminine. Remarks: This lineage includes a few Indo-West Pacific species with a peculiar radula (both rachidian and lateral teeth with long denticles) and a unique jaw shape, small and with an external protrusion on the upper side. The two specimens photographed alive showed a dorsal mantle with several coloured spots. Marsenia indecora Bergh, 1886 (Philippines Sea) belongs to this genus because of its peculiar jaw shape and radular shape. Bergh (1886b) himself regarded this species as remarkably different from all other species he described from the Philippines (that are now included in the genus Marsenia).
Published as part of Fassio, Giulia, Stefani, Matteo, Russini, Valeria, Buge, Barbara, Bouchet, Philippe, Treneman, Nancy, Malaquias, Manuel António E., Schiaparelli, Stefano, Modica, Maria Vittoria & Oliverio, Marco, 2023, Neither slugs nor snails: a molecular reappraisal of the gastropod family Velutinidae, pp. 924-964 in Zoological Journal of the Linnean Society 197 (4) on pages 953-954, DOI: 10.1093/zoolinnean/zlac091, http://zenodo.org/record/7814306
{"references":["Bergh LSR. 1886 b. Nudibranchien. Nachtrage und Erganzungen. In: Semper C, ed. Reisen im Archipel der Philippinen. Malacologische Untersuchungen. Suppl. 3, 129 - 225, pls M - R. Wiesbaden: C. W. Kreidel's Verlag."]}