Vertigo botanicorum Horsák & Pokryszko, 2010, sp. nov.
Creators: name: Horsák, Michal
name: Pokryszko, Beata M.
Publisher: name: Zenodo
Year: 2010
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Gastropoda
Stylommatophora
Vertiginidae
Vertigo
Vertigo botanicorum

description: Vertigo botanicorum sp. nov.
(Fig. 2)
Type locality. Loc. no. 7: 51°30΄26.6″N, 85°35΄48.6″E, Russian Altai Mts., Aktel: Seminski Ridge, Aktel creek valley, 4 km W of the settlement, 13 Aug. 2005, M. Horsák lgt.
Type material. Loc. no. 7: holotype and 1 paratype (NMWP), 2 paratypes (NMPC), 1 paratype (DBZB); Loc. no. 2: 6 paratypes (DBZB); Loc. no. 3: 2 paratypes (DBZB); Loc. no. 4: 1 paratype (DBZB); Loc. no. 6: 1 paratype (DBZB); Loc. no. 8: 1 paratype (DBZB).
Other material examined. Loc. no. 1: 1 specimen; Loc. no. 4: 1 specimen; Loc. no. 3: 1 specimen; Loc. no. 2: 3 specimens (all in DBZB).
Etymology. We dedicate this species to all the botanists who took part in the Altai expeditions: Milan Chytrý, Jiří Danihelka, Nikolai Ermakov, Michal Hájek, Petra Hájková, Martin Kočí, Svatava Kubešová, Pavel Lustyk, Zdenka Otýpková, Barbora Pelánková, and Milan Valachovič. Because of the efforts of these colleagues, the senior author had a remarkable field experience during the Altai Mountains expeditions, and was able to collect considerable field data of a high scientific value.
Description of the shell (n=22, Fig. 2). Shell dextral, height 1.78–2.25 mm (mean 1.98, SD 0.123, holotype 1.85), width 1.08–1.28 mm (mean 1.14, SD 0.056, holotype 1.10), aperture height 0.60–0.78 mm (mean 0.69, SD 0.059, holotype 0.63), aperture width 0.60–0.78 mm (mean 0.68, SD 0.043, holotype 0.65), body whorl height 1.03–1.23 mm (mean 1.12, SD 0.061, holotype 1.05), height/width ratio 1.51–2.00 (mean 1.74, SD 0.119, holotype 1.68), relative height of body whorl 0.50–0.62 (mean 0.57, SD 0.028, holotype 0.55), whorls 4.8–5.4 (mean 4.98, SD 0.16, holotype 4.8). Shell clearly ovate, the body whorl being distinctly broadest, with convex spire and gently rounded apex. Whorls not very convex with a shallow suture. Aperture semi-oval, with palatal margin slightly flattened or with a very shallow indentation. Lip narrow, very slightly thickened, in fresh shells of the same colour as the rest of the shell, narrowly but clearly reflexed on the columellar, basal and lower half of the palatal margin; parietal callus very weak, lip insertions almost not approaching. Aperture with 1–4 vestigial or very small lamellae with the columellar and palatal rather deeply set; all teeth tubercular and white, no trace of a palatal callus even in specimens with four lamellae; the holotype possesses a small columellar and vestigial parietal lamella. In side view the body whorl suture does not or only almost imperceptibly ascend. The outside of the palatal wall lacks a crest, and possesses only a shallow, indistinct furrow corresponding with the upper palatal (even in toothless shells). Shells with two lamellae have a columellar and parietal, shells with a single lamella may have either of the two. The umbilicus is oval and narrow. Shell semitransparent, light golden-brownish, in very fresh shells with a greasy sheen; surface almost completely devoid of growth lines and/or striation, only with the specific microstructure of subparallel, anastomosing periostracal ridges which is more pronounced than in other Ver ti g o species; the few growth lines, if present, are faint, almost invisible.
Comparative notes. The species appears to be a member of a basically northern group including Ve r t i g o modesta (Say, 1824), V. ronnebyensis (Westerlund, 1871), V. ultimathule von Proschwitz, 2007, V. extima (Westerlund, 1877) and some North American members of the V. modesta clade, especially V. modesta hoppii (Möller, 1842), V. cristata (Sterki, 1919), V. coloradensis (Cockerell, 1891), and the undescribed “ Ve rt ig o AK 2” (see Nekola et al. 2009, Nekola & Coles 2010). It is also conchologically similar to V. parcedentata (Al. Braun, 1847) and V. nangaparbatensis Pokryszko et Hlaváč, 2009. It differs from V. modesta, which it resembles in shell shape and dentition pattern, in lighter colour (V. modesta is chestnut-reddish), smaller size (ca. 2/3 height and width), sheen (fresh V. modesta glossy, as if wet) and much smoother shells (in V. modesta clear and rather regular though delicate striae are present). It differs from V. ronnebyensis mainly in surface structure; V. ronnebyensis has fine regular ribs, spire striation and more cylindrical shape. Vertigo botanicorum sp. nov. differs from V. ultimathule and V. e x t i m a in weaker striation and much more pronounced microscopic periostracal ridges of the surface, less convex whorls with shallower suture, smaller size (especially from V. extima) and more ovate shape. It differs from conchologically similar North American species in its microsculpture (Fig. 2 c) and the absence of regular small ribs. In addition, both V. coloradensis and V. cristata possess a marked crest and much stronger lamellae (especially palatal), V. modesta hoppii has a darker, chestnut-red shell with a glossy sheen and weak crest, while “ Ver t ig o AK 2” has pronounced shell striation and often a weakly developed crest that somewhat narrows the aperture. Vertigo botanicorum sp. nov. resembles the syntopic V. parcedentata in shell shape, colour and dentition, but it differs in being somewhat smaller, having a shallower suture and less convex whorls, by possessing a matte sheen (fresh V. parcedentata is glossy as if wet), being more oval (V. parcedentata is often somewhat cylindrical), and having pronounced microscopic periostracal ridges. It also differs from V. nangaparbatensis in being smaller, more ovate, more tumid, having poorly developed dentition and much more pronounced microscopic periostracal ridges (Fig. 2 c). This characteristic microsculpture is also developed in other sympatric Ve rt ig o species, such as V. pygmaea (Draparnaud, 1801), V. substriata (Jeffreys, 1833) and V. microsphaera Schileyko, 1984, which differ in many external features and the apertural barriers. However, no studies of this microsculpture have been conducted and its phylogenetic relevance is completely unknown.
Ecology. This new species has a rather broad ecological amplitude. It was found in different mesic and wet habitats such as hemiboreal forests, subalpine shrub vegetation, and mostly shrubby meadow steppes (Festuco-Brometea). It avoided only strictly open and dry sites. This snail occurred along a relatively broad range of site basicity (topsoil electric conductivity 33–164 µS/cm and pH 5.4–6.7). Like V. modesta hoppii from North America (Nekola & Coles 2010), V. b o t a n i c o r u m sp. nov. was mostly found in rather acidic sites and avoided calcareous substrates. Most sites were at high altitudes (above 1350 m a.s.l.), but occurred also at two rather low sites (around 500 m a.s.l., see Appendix 1). Population densities were intermediate or low, varying from 1 to 10 recorded specimens per site. All species co-occurring with V. b o t a n i c o r u m sp. nov. at the studied sites are given in Table 1. Euconulus fulvus (O.F. Müller, 1774), Perpolita hammoni s (Ström, 1765), Novisuccinea altaica (Martens, 1879) and Vertigo microsphaera were the species most often co-occurring with the species described here (Tab. 1).
description: Published as part of Horsák, Michal & Pokryszko, Beata M., 2010, Vertigo botanicorum sp. nov. (Gastropoda: Pulmonata: Vertiginidae) — a new whorl-snail from the Russian Altai Mountains, pp. 57-62 in Zootaxa 2634 on pages 58-61, DOI: 10.5281/zenodo.276148