HAINOTINAE FASSIO, BOUCHET, SCHIAPARELLI & OLIVERIO, 2023

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, Zoological Journal of the Linnean Society 197 (4), pp. 924-964 : 949-950

HAINOTINAE FASSIO, BOUCHET, SCHIAPARELLI & OLIVERIO SUBFAM. NOV.

( FIGS 2 , 3 , 4G , 6B )

Zoobank registration: urn: lsid: zoobank. org:act: A356DC93-B469-4DC0-B075-ED51CAEBDAA4

Type genus: Hainotis F. Riedel, 2000 .

Included genera: Hainotis F. Riedel, 2000 , Mysticoncha J. K. Allan, 1936 .

Description: Body of small to medium size, 0.5– 5.0 cm total length. Shell thin to very thin, weakly calcified, ear shaped, high spire, with expanded aperture, smooth, with or without growth lines, completely enclosed by the mantle. Periostracum thin to moderately developed and hairy.

Protoconch of 1.7–2.1 whorls; protoconch I of 0.6 whorls, smooth or with weak growth striations, nucleus diameter 86 µm; protoconch–teleoconch boundary not always distinct.

Mantle dome shaped, outline rounded or polygonal (low ridges dividing the mantle into six areas, from a raised hexagonal area at the centre of the dorsum); thin to thick; with anterior elongated siphonal fold; colour highly variable, almost transparent to white, grey, beige, yellow, orange, red, violet, brown or black, frequently patterned with dots and/or polygonal shape lines.

Penis and vas deferens unknown.

Radula taenioglossate, formula 2:1:1:1:2; rachidian tooth elongated, with rectangular base; rachidian cusp with two external denticles on each side; lateral teeth elongated, with a pointed external cusp, with one denticle on the internal side and two on the external side; marginals narrow, with one small denticle on the internal side.

Jaws elongated, with masticatory denticles.

Distribution: North-eastern Pacific (from Oregon to northern Mexico), South Australia, New Zealand; 0–45 m deep.

Remarks: This subfamily is represented in the phylogenetic tree only by specimens of Hainotis sharonae described from the coast of California (type locality: Anaheim Bay, Orange County, CA, USA; Willett, 1939). This lineage is diagnosed by its shell with a higher spire, a radular formula of 2:1:1:1:2 with elongated central and lateral teeth, and an elongated anterior siphonal fold.

Pending further molecular analysis, we suggest also including the genus Mysticoncha in this subfamily because its radular formula and shape, shell shape, siphon shape and temperate distribution (South Australia, Victoria and New Zealand) are consistent with those of the type genus, Hainotis .

Figures

Figure 2. Phylogenetic relationships of the family Velutinidae (Bayesian tree based on the combined dataset), with clades (A–L) collapsed by genera. Numbers at nodes indicate branch support values [posterior probability (PP) and ultrafast bootstrap (UFb) values, respectively]; support values are shown only when at least one of them is ≥ 80%; white circles at nodes indicate maximum support (PP = 1, Ufb = 100). On the right side of the tree, for each genus is reported a representative photograph of the shell, a schematic representation of the radula, the depth range (in metres) and the geographical distribution.

Figure 3. Phylogenetic relationships of the family Velutinidae (Bayesian tree based on the combined dataset) showing clades A–L expanded. Numbers at nodes indicate branch support values [posterior probability (PP) and ultrafast bootstrap (UFb) values, respectively]; support values are shown only when at least one of them is ≥ 80%; white circles at nodes indicate maximum support (PP = 1, Ufb = 100). Boxes indicate hypothetical species; dashed lines indicate possible alternative species partitions. Coloured boxes on the right indicate genera, and white boxes indicate subfamilies. Letters at the end of sample codes broadly indicate the area of origin:AK, Alaska; ANT, Antarctica; AR, Argentina; BC, British Columbia; BRE, Bretagne; CA, California; CH, China; COR, Corse; CR, Costa Rica; FL, Florida; GF, French Guiana; GP, Guadeloupe; HI, Hawaii; IT, Italy; MG, Madagascar; MQ, Martinique; MX, Mexico; MZ, Mozambique; NC, New Caledonia; NL, Newfoundland; NO, Norway; OR, Oregon; PA, Panama; PF, French Polynesia; PG, Papua New Guinea; PH, Philippines; QLS, Queensland; RE, Reunion; SA, Saudi Arabia; SP, Spain; TAS, Tasmania; TW, Taiwan; VU, Vanuatu; WA, Washington State; ZNZ, Zanzibar.

Figure 4. A, Marseniopsis sp. (M9), MNA 5376. B, Marseniopsis conica, MNA 5361. C, Marsenina zadei, LACM 182861. D, Marsenina rhombica, LACM 182862. E, Limneria prolongata, LACM 182858. F, Velutina sp., LACM 182869. G, Hainotis sharonae. H, Variolipallium regium sp. nov., MNHN-IM-2013-69285, holotype. I, Variolipallium sp. (L3), MNHN-IM-2013-69605. J, Variolipallium sp. (L10), MNHN-IM-2013-69280. Photograph credits: A, B, MNA, Stefano Schiaparelli; C–F, Nancy Treneman; G, iNaturalist, Robin Gwen Agarwal; H–J, MNHN, Philippe Maestrati. For the sequenced specimens, the corresponding species code (see Fig. 3) is reported in parentheses.

Figure 6. Velutinidae shells. A, Marseniopsis conica, BAS 03-764. B, Hainotis sharonae, LACM 1059, holotype (after Willet, 1939: fig. 1 and 1a). C, Marsenina rhombica, BAU 4229. D, Limneria prolongata, BAU 4228. Scale bars: A, 1 mm; C, D, 5 mm; B, shell maximum diameter = 5.5 mm, shell height 7.4 mm.