Velutininae Gray 1840
Creators: name: Fassio, Giulia
name: Stefani, Matteo
name: Russini, Valeria
name: Buge, Barbara
name: Bouchet, Philippe
name: Treneman, Nancy
name: Malaquias, Manuel António E.
name: Schiaparelli, Stefano
name: Modica, Maria Vittoria
name: Oliverio, Marco
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Littorinimorpha
Velutinidae

description: VELUTININAE GRAY, 1840
(FIGS 2, 3, 4C–F, 6C, D, 9B, 10B, C, 11B, C, N, O)
Velutininae Gray, 1840: 90;
type genus Velutina J. Fleming, 1820.
Marseninidae Odhner, 1913: 9 [as Marsenininae];
type genus Marsenina Gray, 1850.
Sacculidae Thiele, 1929: 266;
type genus Sacculus Hirase, 1927 [permanently invalid, being the type genus a junior homonym of Sacculus Grosse, 1851 (Rotifera)].
Pseudosacculidae Kuroda, 1933: 186 [replacement name for Sacculidae Thiele];
type genus Pseudosacculus Hirase, 1928.
Capulacmaeidae Golikov & Gulbin, 1990: 108 [as Capulacmaeinae];
type genus Capulacmaea M. Sars, 1859.
Included genera: CartilagoƲelutina Golikov & Gulbin, 1990, CiliatoƲelutina Golikov & Gulbin, 1990, Cilifera Golikov & Gulbin, 1990, Limneria H.Adams & A. Adams, 1851, Marsenina Gray, 1850, Onchidiopsis Bergh, 1853, Piliscus Lovén, 1859, Pseudosacculus Hirase, 1928, Pseudotorellia Warén, 1989, TorelliƲelutina J. H. McLean, 2000, Velutina J. Fleming, 1820.
Description: Body of small to medium size for the family, 0.5–11.0 cm total length. Shell moderately thin to thick, weakly to strongly calcified; ear, shield or cap shaped, low to high spire, with expanded aperture; smooth or weakly sculptured by axial growth lines; exposed or completely enclosed by the mantle. Periostracum moderately or well developed, occasionally hairy.
Protoconch of 1.1–2.0 whorls; protoconch I of 0.50– 0.64 whorls, nucleus diameter 125–186 μm, smooth or with microgranules; protoconch–teleoconch boundary not always visible.
Mantle flat or dome shaped, outline rounded; thick or thin, with or without dorsal tubercles; with or without anterior and right lateral siphonal folds; texture smooth, wrinkled or jelly-like; colour highly variable, almost transparent to white, grey, beige, yellow, orange, brown, often patterned.
Penis to the right of the right cephalic tentacle, with tip of the seminal duct protruding from the penis tip. Vas deferens without a free loop in haemocoel.
Radula taenioglossate, formula 2:1:1:1:2, rachidian tooth squared, with broad base, rachidian cusp with or without one to six pronounced external denticles; lateral teeth squared or elongated, with a pointed triangular internal or external cusp, with or without one to six denticles on both sides; marginals narrow, with or without one small denticle on the internal side.
Jaws short to elongated, composed of scale-like elements, with denticles on the masticatory margin.
Distribution: Arctic and temperate regions worldwide, 0–1200 m deep.
Remarks: Velutinines can be diagnosed by their squared rachidian tooth with a broad base, and the jaws composed of scale-like elements, with denticles. Their shells can range from strongly calcified and completely exposed (e.g. Velutina) to almost without calcification and completely enveloped by the mantle (e.g. Onchidiopsis). Some genera (e.g. Velutina and Limneria) also have a hairy periostracum. In addition to the anterior inhalant siphon, an exhalant siphon is made by a right lateral mantle fold in some genera (e.g. Marsenina and Onchidiopsis). Before the present study, six genera (two of them with subgenera; see Gulbin & Golikov, 1997) were classified in this subfamily. However, the present molecular phylogeny suggests that Limneria and Velutina might be synonyms. In addition, pending molecular analysis of the type material, we propose to place Pseudosacculus in this subfamily, based on the description of the only included species, Pseudosacculus okai (Hirase, 1927). The radular formula (2:1:1:1:2) and morphology (Hirase, 1927: 125, fig. 8) and the presence of a small dorsal aperture in the mantle are congruent with this placement. It should be noted that Pelseneer (1935) suggested that Pseudosacculus okai might be classifiable in Marsenina, which would make Pseudosacculus a junior synonym.
description: 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 page 950, DOI: 10.1093/zoolinnean/zlac091, http://zenodo.org/record/7814306