Refugial occurrence and ecology of the land snail Vertigo lilljeborgi in fen habitats in temperate mainland Europe

Vertigo lilljeborgi (Westerlund, 1871) is one of the rarest terrestrial snail species in temperate mainland Europe, traditionally considered a glacial relict there. This contrasts with its occurrence in northern Europe where it is a widespread species. This species prefers constantly wet habitats that are neutral to slightly acidic, and avoids highly alkaline conditions, which is an extremely rare ecology for a Eurasian mollusc. Until 2012, only five historical records of this species were known in mainland Europe to the south of its main distribution in northern Europe. Since then, 20 new sites have been discovered, mostly located in the Hercynian Mountains (Bohemian Massif in the Czech Republic and Massif Central in France). In comparison with the boreal European and Alpine populations, those from the Hercynian Mountains inhabit acidic, rather soligenous and productive fens, strongly dominated by Sphagnum. Vertigo lilljeborgi does not occur in some sites with apparently suitable habitats as indicated by species composition of the vegetation. We observed a surprising correspondence between the occurrence of V. lilljeborgi and mean July air temperature and we report its first fossil record from the last glacial period from Central Europe. Although the number of its sites has increased recently, these sites represent unusual and highly unique habitats, vulnerable to drainage and destruction from human activities. This calls for a need of conservation efforts in most of the newly discovered isolated sites

Climate gradients, and patterns of biodiversity and biotic homogenization in urban residential yards

Residential yards constitute a substantive biodiverse greenspace within urban areas. This biodiversity results from a combination of native and non-native species and can contribute to biotic homogenization. Geographical climatic patterns affect the distribution of native species and may differently affect non-native species. In this study, we examined biodiversity and biotic homogenization patterns of yard-dwelling land snails across 12 towns in Oklahoma and Kansas (USA). The 3 x 4 array of towns incorporated a N-S winter temperature gradient (mean low January temperature range = -8.4 to 0.1°C) and an E-W annual rainfall gradient (annual rainfall range = 113.8 to 61.3 cm/yr). Ten yards per town were surveyed. We hypothesized that mild winter temperatures and greater annual rainfall would be associated with greater snail abundance and richness, and that the presence of non-native species would contribute to biotic homogenization. Non-native snails were present and often abundant in all towns. Snail communities varied with both rainfall and cold temperature. Contrary to our prediction, snail abundance was inversely related to annual rainfall–likely because drier conditions resulted in greater yard watering that both augmented rainfall and maintained moist conditions. Sørensen similarity between towns for the entire land snail community and for only non-native species both showed distance-decay patterns, with snail composition becoming less similar with increasing distance—patterns resulting from species turnover. The biotic homogenization index also showed a distance-related pattern, such that closer towns were more likely to have biotic homogenization whereas more distant towns tended to have biotic differentiation. These results support the concept that biotic homogenization is more likely regionally and that climatic changes over distance result in species turnover and can reduce spatially broad biotic homogenization.Funding was provided by the University of Oklahoma: SRI funds, Oklahoma Biological Survey small grants program, and University Libraries (all to EAB). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Open Access fees paid for in whole or in part by the University of Oklahoma LibrariesYe

Alpine Crossroads or Origin of Genetic Diversity? Comparative Phylogeography of Two Sympatric Microgastropod Species

The Alpine Region, constituting the Alps and the Dinaric Alps, has played a major role in the formation of current patterns of biodiversity either as a contact zone of postglacial expanding lineages or as the origin of genetic diversity. In our study, we tested these hypotheses for two widespread, sympatric microgastropod taxa – Carychium minimum O.F. Müller, 1774 and Carychium tridentatum (Risso, 1826) (Gastropoda, Eupulmonata, Carychiidae) – by using COI sequence data and species potential distribution models analyzed in a statistical phylogeographical framework. Additionally, we examined disjunct transatlantic populations of those taxa from the Azores and North America. In general, both Carychium taxa demonstrate a genetic structure composed of several differentiated haplotype lineages most likely resulting from allopatric diversification in isolated refugial areas during the Pleistocene glacial periods. However, the genetic structure of Carychium minimum is more pronounced, which can be attributed to ecological constraints relating to habitat proximity to permanent bodies of water. For most of the Carychium lineages, the broader Alpine Region was identified as the likely origin of genetic diversity. Several lineages are endemic to the broader Alpine Region whereas a single lineage per species underwent a postglacial expansion to (re)colonize previously unsuitable habitats, e.g. in Northern Europe. The source populations of those expanding lineages can be traced back to the Eastern and Western Alps. Consequently, we identify the Alpine Region as a significant ‘hot-spot’ for the formation of genetic diversity within European Carychium lineages. Passive dispersal via anthropogenic means best explains the presence of transatlantic European Carychium populations on the Azores and in North America. We conclude that passive (anthropogenic) transport could mislead the interpretation of observed phylogeographical patterns in general

Vertigo botanicorum Horsák & Pokryszko, 2010, sp. nov.

<i>Vertigo botanicorum</i> sp. nov. <p>(Fig. 2)</p> <p> <b>Type locality.</b> Loc. no. <b>7</b>: 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.</p> <p> <b>Type material.</b> Loc. no. <b>7</b>: holotype and 1 paratype (NMWP), 2 paratypes (NMPC), 1 paratype (DBZB); Loc. no. <b>2</b>: 6 paratypes (DBZB); Loc. no. <b>3</b>: 2 paratypes (DBZB); Loc. no. <b>4</b>: 1 paratype (DBZB); Loc. no. <b>6</b>: 1 paratype (DBZB); Loc. no. <b>8</b>: 1 paratype (DBZB).</p> <p> <b>Other material examined</b>. Loc. no. <b>1</b>: 1 specimen; Loc. no. <b>4</b>: 1 specimen; Loc. no. <b>3</b>: 1 specimen; Loc. no. <b>2</b>: 3 specimens (all in DBZB).</p> <p> <b>Etymology.</b> 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.</p> <p> <b>Description of the shell</b> (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 <i>Ver ti g o</i> species; the few growth lines, if present, are faint, almost invisible.</p> <p> <b>Comparative notes.</b> The species appears to be a member of a basically northern group including <i>Ve r t i g o</i> <i>modesta</i> (Say, 1824), <i>V. ronnebyensis</i> (Westerlund, 1871), <i>V. ultimathule</i> von Proschwitz, 2007, <i>V. extima</i> (Westerlund, 1877) and some North American members of the <i>V. modesta</i> clade, especially <i>V. modesta hoppii</i> (Möller, 1842), <i>V. cristata</i> (Sterki, 1919), <i>V. coloradensis</i> (Cockerell, 1891), and the undescribed “ <i>Ve rt ig o</i> AK 2” (see Nekola <i>et al.</i> 2009, Nekola & Coles 2010). It is also conchologically similar to <i>V. parcedentata</i> (Al. Braun, 1847) and <i>V. nangaparbatensis</i> Pokryszko et Hlaváč, 2009. It differs from <i>V. modesta</i>, which it resembles in shell shape and dentition pattern, in lighter colour (<i>V. modesta</i> is chestnut-reddish), smaller size (ca. 2/3 height and width), sheen (fresh <i>V. modesta</i> glossy, as if wet) and much smoother shells (in <i>V. modesta</i> clear and rather regular though delicate striae are present). It differs from <i>V. ronnebyensis</i> mainly in surface structure; <i>V. ronnebyensis</i> has fine regular ribs, spire striation and more cylindrical shape. <i>Vertigo botanicorum</i> <b>sp. nov.</b> differs from <i>V. ultimathule</i> and <i>V. e x t i m a</i> in weaker striation and much more pronounced microscopic periostracal ridges of the surface, less convex whorls with shallower suture, smaller size (especially from <i>V. extima</i>) 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 <i>V. coloradensis</i> and <i>V. cristata</i> possess a marked crest and much stronger lamellae (especially palatal), <i>V. modesta hoppii</i> has a darker, chestnut-red shell with a glossy sheen and weak crest, while “ <i>Ver t ig o</i> AK 2” has pronounced shell striation and often a weakly developed crest that somewhat narrows the aperture. <i>Vertigo botanicorum</i> <b>sp. nov.</b> resembles the syntopic <i>V. parcedentata</i> 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 <i>V. parcedentata</i> is glossy as if wet), being more oval (<i>V. parcedentata</i> is often somewhat cylindrical), and having pronounced microscopic periostracal ridges. It also differs from <i>V. nangaparbatensis</i> 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 <i>Ve rt ig o</i> species, such as <i>V. pygmaea</i> (Draparnaud, 1801), <i>V. substriata</i> (Jeffreys, 1833) and <i>V. microsphaera</i> 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.</p> <p> <b>Ecology.</b> 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 (<i>Festuco-Brometea</i>). 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 <i>V. modesta hoppii</i> from North America (Nekola & Coles 2010), <i>V. b o t a n i c o r u m</i> <b>sp. nov.</b> 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 <i>V. b o t a n i c o r u m</i> <b>sp. nov.</b> at the studied sites are given in Table 1. <i>Euconulus fulvus</i> (O.F. Müller, 1774), <i>Perpolita hammoni</i> s (Ström, 1765), <i>Novisuccinea altaica</i> (Martens, 1879) and <i>Vertigo microsphaera</i> were the species most often co-occurring with the species described here (Tab. 1).</p>Published as part of <i>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</i> on pages 58-61, DOI: <a href="http://zenodo.org/record/276148">10.5281/zenodo.276148</a&gt