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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.
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.
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.
Badania ślimaków lądowych przeprowadzono w 2004 roku w Parku Krajobrazowym Wzniesień Łódzkich (PKWŁ), znajdującym się na północny wschód od Łodzi. Miały one na celu ustalenie listy gatunków występujących na tym obszarze, określenie ich preferencji siedliskowych, a także wytypowanie miejsc o największym znaczeniu dla zachowania tej grupy bezkręgowców w regionie. Poszukiwania metodą „na upatrzonego” przeprowadzono na 47 stanowiskach reprezentujących fragmenty naturalnych lasów w rezerwatach przyrody („Las Łagiewnicki”, „Parowy Janinowskie”, „Struga Dobieszkowska”), siedliska półnaturalne (łąki w dolinach rzek) oraz parki, ogrody i cmentarze. Łącznie na terenie PKWŁ stwierdzono występowanie 51 gatunków ślimaków lądowych, w tym cztery wykazano po raz pierwszy w okolicach Łodzi: poczwarówkę rozdętą Vertigo antivertigo, poczwarówkę malutką Truncatellina cylindrica, stożeczka Euconulus praticola i ślinika leśnego Arion silvaticus. Do gatunków zagrożonych należą: błyszczotka lśniąca Cochlicopa nitens oraz wpisana na Czerwoną listę szklarka zielonawa Nesovitrea petronella. W PKWŁ zanotowano występowanie kilku gatunków synantropijnych, prawdopodobnie zawleczonych z roślinami, m.in. szklarki Draparnauda Oxychilus draparnaudi i ślinika wielkiego Arion rufus. Na najbogatszych stanowiskach (łęgi w rezerwatach „Las Łagiewnicki” i „Struga Dobieszkowska”) występuje 25–26 gatunków ślimaków. Bogaty zespół fauny wilgociolubnej występuje także w siedliskach łąkowych w dolinie Moszczenicy
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).
We quantified the mollusc assemblage composition in eight riverine forests inhabited by the door snail Alinda biplicata (Montagu) in Central Poland where it occurs at the north-eastern border of its distribution range. In each location, eight random 0.25 m2 plots were quantitatively sampled from a 400 m2 core area that was searched for additional species. A total of 54 species were found, composed of 46 terrestrial snails and slugs, six freshwater gastropod and two clam species. Abundances ranged from 220 to 4,400 ind.m–2 per location, with a maximum of 2,200 individuals per plot. The number of taxa ranged from 17 to 34 per location and from 3 to 23 per plot. A. biplicata occurred in each randomly sampled plot. The highest number of co-occurrences with Alinda was found for Carychium tridentatum and Nesovitrea hammonis. Additionally, forest-specific, wetland-specific and even dry habitat-specific snails can use the same patch of microhabitat. The lack of narrow ecological specialisation in A. biplicata may favour its presence in man-made habitats where it is sometimes considered an invasive native gastropod. The species list included invasive Arion vulgaris and some other species with a mainly West European distribution, such as Oxychilus draparnaudi, O. alliarius, Arion rufus, Cepaea nemoralis and C. hortensis. The eastern borders of the native ranges of these species reach into the western part of Poland but in the sampled region they seem to be recent arrivals. Our results indicate that “western” (Atlantic) faunal elements benefit from more balanced microclimate in wet floodplain forests, which possibly reduces macroclimatic constraints at their distribution border.
Balea fallax (Rossm.) collected from the Roztocze Upland (SE. Poland) was kept in the laboratory for four years. Observations were conducted between March and October when the snails were kept at room temperature (18-25°C); in winter they were stored at 3°C. The egg-laying period started in late March and lasted till October, with maxima in spring and early autumn. The snails laid oval, gelatinous eggs with separatecalcium carbonate crystals in the external envelope (average egg size 1.96 × 1.73 mm). The eggs were deposited in batches (up to 14 eggs at a time) or singly. The number of batches per snail per year ranged between 1and 4. Snails isolated before maturation laid defective eggs which failed to develop, which suggest that the speciesis incapable of uniparental reproduction or at least the ability is very limited. The reproduction rate decreased during consecutive years, probably as a result of the aging or the shortage of allosperm in isolated individuals.Compared to batches of typically oviparous clausiliids, eggs of B. fallax hatched slightly earlier (interval between oviposition and hatching lasted 8-10 days at room temperature). It is likely that the adults retained developing eggs in the uterus for a short time. The juveniles needed at least 6 months to attain the ultimates hell size.
Balea stabilis (L. Pfeiffer) collected from two localities in the Polish Carpathians were kept in the laboratory for more than four years. Observations were conducted between March and October when the snails were kept at room temperature (18-25°C); in winter they were stored at 3°C. The egg-laying period started in late March and lasted till the middle of September, with the maximum in April-May. The eggs were oval, gelatinous, with separate calcium carbonate crystals in the external envelope (average egg size 1.69 × 1.47 mm). They were deposited in batches, usually of 5-9 eggs (mean 6.9). The number of batches per snail per year was 1-7; the corresponding number of eggs - 3-41. At room temperature the incubation took 15-21 days; the hatching success was 71.9%.
Vestia gulo and V. turgida are iteroparous simultaneous hermaphrodites. In the wild they are active from April till October; they reproduce in the spring and summer (egg retention from May to August), and hibernate from November till March. Their gonads show the greatest activity in the spring and summer (maturation of oocytes, intensive vitellogenesis: March–May, numerous mature oocytes: May–July; production and maturation of spermatozoa: March–May; numerous packets of mature spermatozoa: May–October), which coincides with the reproductive season. The onset of reproduction is determined by the size of the pool of vitellogenic and mature oocytes; oocyte production starts in the summer of the previous vegetation season and lasts till next spring. Mature spermatozoa are present in the gonad from spring till autumn which indicates an ability to mate during the whole active period. During hibernation the gonads contain no spermatids, mature spermatozoa or advanced vitellogenic oocytes.
The maturation, growth and reproduction of Alinda biplicata in the laboratory were studied over a five-year period. The snails were kept in pairs and groups of a few individuals. The initial material came from two populations from SW. Poland. The snails reproduced during the whole year, more intensively in the spring and autumn. We confirmed the ovoviviparity of A. biplicata: the whole embrynic development takes place in eggs retained in the parent's uterus. The snails gave birth to juveniles (no egg-laying was observed), and the uteri of dissected individuals contained from 3 to 15 eggs. The number of juveniles per litter was 1 to 8. The snails produced 3 to 20 juveniles in 2-9 batches per year. The neonate shells had 2.1-2.9 whorls and height of 1-1.6 mm. Growth to adulthood lasted 20 to 56 weeks and the time increased with increasing density of snails. The snails became sexually mature 5-6 months after completeion of shell growth and formation of the closing apparatus. The juvenile mortality ranged from 16.7% to 60.6% and increased with density. The life span in the laboratory was 220 to 295 weeks (4 to 6 years). These results are compared with those for other species; A. biplicata resembles other large ovoviviparous Clausiliidae species.
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