Micro-CT screening of old shell collections helps to understand the distribution of viviparity in the highly diversifed clausiliid clade of land snails

Current zoological research may benefit in many ways from the study of old collections of shells. These collections may provide materials for the verification of broad zoogeographical and ecological hypotheses on the reproduction of molluscs, as they include records from many areas where sampling is currently impossible or very difficult due to political circumstances. In the present paper we present data on viviparous and embryo-retention reproductive modes in clausiliid land snails (subfamily Phaedusinae) acquired from specimens collected since the nineteenth century in the Pontic, Hyrcanian, and East and Southeast Asian regions. X-ray imaging (micro-CT) enabled relatively quick screening of more than 1,000 individuals classified within 141 taxa, among which we discovered 205 shells containing embryos or eggs. Gravid individuals were found to belong to 55 species, representing, for some of these species, the first indication of brooding reproductive strategy

Malacofauna of a city park - turnover and persistence of species through 40 years

In urban areas the turnover of species is fairly rapid, species of natural habitats become eliminated and invasion of alien species takes place. An example of these process was investigated in £ódŸ, Poland. The present mollusc fauna of a city park was compared with the results obtained 40 years ago. The estimated turnover index for terrestrial gastropods was 0.29 and for molluscs of park ponds – 0.4. In the recent inventory 57 species were recorded, compared to the 48 in the 1950s. Some stenoecious gastropods, e.g. Discus ruderatus, Ruthenica filograna, Malacolimax tenellus, Nesovitrea petronella were not re-found. Species recorded for the first time included synanthropic Oxychilus draparnaudi, Helix pomatia, Cepaea nemoralis, Arion rufus, Limax maximus and open-country snails, e.g. Cochlicopa lubricella and Vallonia excentrica. Considerable changes were observed in the composition of the malacofauna of park ponds. The following species were found for the first time: Viviparus contectus, Potamopyrgus antipodarum, Hippeutis complanatus and Anodonta cygnaea. The newly recorded species were probably brought with soil, plants, stocking fish, could be transported by birds or introduced on purpose. The changes in the fauna result also from intense penetration by humans, decrease in the ground water level, emptying and cleaning of the ponds and changes in the water supply

Distribution and habitat preferences of Clausiliids (Gastropoda: pulmonata: Clausiliidae) in the eastern part of the Polish Carpathians

Seventeen species of Clausiliidae are recorded from the Bieszczady Mts, the Beskid Niski Mts and the Sanocko-Turczañskie Mts. Five (Macrogastra borealis (O. Boettger), M. tumida (Rossm.), Balea stabilis (L. Pfeiffer), Vestia gulo (E. A. Bielz) and Bulgarica cana (Held)) are common in all the studied regions. Balea fallax (Rossm.), Vestia elata (Rossm.), Clausilia dubia Drap. and C. pumila C. Pfeiffer are the rarest species. Macrogastra plicatula (Drap.) and Balea biplicata (Mont.) inhabit only the western part of the Beskid Niski Mts. The distribution of species was investigated with reference to altitude above sea level, habitat and microhabitat types. Ruthenica filograna (Rossm.), Macrogastra plicatula (Drap.), Laciniaria plicata (Drap.) and Balea biplicata (Mont.) occur below 800 m a.s.l. Clausilia cruciata Studer and Balea stabilis (L. Pfeiffer) are absent below 400 m a.s.l. The richest communities (up to 8 clausiliid species recorded sympatrically) inhabit alder forests in the valleys. Macrogastra tumida (Rossm.), Ruthenica filograna (Rossm.) and Vestia turgida (Rossm.) are characteristic for these habitats. Beech woods are inhabited by tree-climbing clausiliids (Cochlodina orthostoma (Menke), Clausilia cruciata Studer, Macrogastra borealis (O. Boettger), Bulgarica cana (Held)) and – in more humid sites – by litter dwellers (M. tumida (Rossm.), Vestia gulo (E. A. Bielz), V. turgida (Rossm.)). In the studied region Laciniaria plicata (Drap.) prefers anthropogenic habitats (e.g. stone walls, cemeteries)

Nature reserves Grądy nad Moszczenicą and Grądy nad Lindą - refuges of forest malacofauna in central Poland

In 2007 and 2009 two forest nature reserves situated in the environs of Łódź, Central Poland, were sampled by visual search and sieving litter samples to produce complete lists of terrestrial gastropods. Four sites representing various plant communities were searched in each reserve (Tilio-Carpinetum typicum, Tilio-Carpinetum stachyetosum, Fraxino-Alnetum, Ribeso nigri-Alnetum). The resulting material included 3,217 specimens representing 44 species of gastropods (including 38 terrestrial) and bivalves (Pisidium sp.). Thirty eight gastropod species were recorded from Grądy nad Moszczenicą (among them five slugs and four freshwater snails); and 35 from Grądy nad Lindą (among them six slugs and four freshwater snails). The richest sites (Fraxino-Alnetum in Grądy nad Moszczenicą and Ribeso nigri-Alnetum in Grądy nad Lindą) harboured 27 and 26 terrestrial gastropod species, respectively. Some species were recorded for the first time in the region, namely: Acicula polita (Hartmann), Vertigo alpestris Alder and Clausilia cruciata (Studer). The rich malacofauna with three coexisting clausiliid species (Alinda biplicata (Montagu), Ruthenica filograna (Rossmässler) and Clausilia cruciata (Studer)) in Grądy nad Moszczenicą indicates a small degree of habitat destruction in the nature reserve

Shell variability in Vestia turgida (Rossmassler, 1836) (Gastropoda, Clausiliidae) along an altitudinal gradient

281 shells of Vestia turgida (Rossm.) were collected between 380 and 1,250 m a.s.l. in the Carpathians (Poland). Biometrical analysis revealed a correlation between metric characters of the shell, indices of shell shape and altitude. Snails living above the timberline had conspicuously smaller and stouter shells with weaker apertural barriers. The aperture shape did not differ along the altitudinal gradient. The stronger erosion of the shell surface at higher elevations depends probably on a longer juvenile period