Cornu aspersum (Gastropoda: Helicidae) in Western Ukraine with an overview of introduced species of land molluscs from this area

The first findings of Cornu aspersum in the Lviv region are described, including the shell size and shell colouration variability. A review of the known records of C. aspersum in different regions of Ukraine, from the second half of the 19th century to the present day, is also presented. The most probable ways of penetration and the possibility of further acclimatization of this species in Western Ukraine are discussed. The chronology of the records of introduced species of land molluscs in Western Ukraine is described in tabular form, which, to a large extent, should reflect the chronology of their penetration into this area. It is noted that the majority of alien species began to be found in Western Ukraine only at the end of the 20th or the beginning of the 21st century. Simultaneously several species appeared here, previously known only for the south of the country.

Effects of Cadmium Sulfate on the Brown Garden Snail Cornu aspersum: Implications for DNA Methylation

An extensive literature exists regarding the cellular, physiological, and genetic effects of cadmium (Cd)—A highly toxic, but commonly used trace metal in modern industry. However, limited data are available on its epigenetic effects, especially for terrestrial sentinel invertebrates. We determined Cd retention, total DNA methylation, and the methylation status of 5′ end of the Cd-MT gene in the hepatopancreas of the brown garden snail, Cornu aspersum, fed Cd sulfate for four weeks. Bodyweight changes and survival were also measured. Hepatopancreas cadmium increased in a dose-dependent manner from the third-lowest dose onward, with very large amounts being found for the highest treatment group. However, no mortalities occurred, irrespective of dietary Cd dose. We identified significant genome-wide hypermethylation in specimens given the highest dose, which overlapped with a significant bodyweight decrease. The Cd-MT gene showed an unmethylated 5′ end of the Cd-MT gene and this status was not affected by cadmium exposure. Hepatopancreas DNA methylation is as sensitive as bodyweight to non-lethal concentrations of dietary Cd given as cadmium sulfate but less responsive than tissue accumulation. Such an exposure event, by contrast, does not affect the methylation status of the Cd-MT gene 5′ end.

Composição da malacofauna terrestre urbana de União da Vitória, extremo sul do Paraná, Brasil / Composition of the urban terrestrial malacofauna of União da Vitória, extreme south of Paraná, Brazil

Os gastrópodes terrestres enfrentam um grave problema, além das alterações nos ambientes naturais, sofrem a competição direta com espécies exóticas e pela introdução demasiada dessas espécies. Nesse sentido, este estudo teve como objetivo realizar um inventário das espécies de gastrópodes terrestres em União da Vitória, extremo sul do Paraná, com a finalidade de fornecer informações para análises ecológicas e taxonômicas em uma área urbana. Na zona urbana central foram amostradas 20 áreas domiciliares, durante os meses de junho, setembro e dezembro de 2019 e março de 2020. Em cada local, os gastrópodes foram coletados usando três quadrantes com área amostral de 5 m2. As amostragens envolveram padronização de esforço amostral através do método de coleta ativa manual. Um total de 10 famílias, 15 espécies e 1.835 espécimes foram registrados na biocenose estudada. As espécies Leptinaria sp., Happia insularis, Belocaulus angustipes e Succinea aff. burmeisteri foram encontradas em apenas uma coleta. As espécies dominantes foram Bradybaena similaris (70,3%, n = 1.290), Phyllocaulis soleiformis (10,7%, n = 196) e Achatina fulica (7,85%, n = 144) totalizando 88,85 % dos espécimes coletados. As espécies constantes foram Bradybaena similaris, Achatina fulica, Cornu aspersum, Limax maximus, Limacus flavus, Phyllocaulis soleiformis e Meghimatium pictum. Entre as espécies encontradas, sete são espécies exóticas introduzidas. A utilização de uma metodologia de coleta adequada para ambiente urbano possibilitou a amostragem de espécimes que apresentam preferência por hortas, jardins, plantações, terrenos baldios e solo. De uma maneira geral, a fauna de moluscos foi subrepresentada, entretanto, a riqueza tanto das espécies exóticas quanto as espécies nativas foi equivalente, o que é esperado em centros urbanos.

Diversity and abundance of terrestrial gastropods in Skikda region (North-East Algeria): correlation with soil physicochemical factors

Background The inventory process is the first method to protect and safeguard animal biodiversity. This study carries out a quantitative and qualitative inventory of terrestrial gastropods at three sites in Skikda province (north-eastern Algeria). The relationship between terrestrial gastropod diversity and soil physicochemical factors was investigated using statistical analyses. Results The inventory data reveals the presence of four families and eight species showing varied predominance rates of Cornu aspersum species according to each site in the city of Skikda (Azzaba 53.88%; Ben-Azzouz 56.12%; El-Hadaiek 37.92%). The maximal specific richness was registered in the El-Hadaiek site (seven species), and the highest mean richness was noted in the Ben-Azzouz site (392 individuals). Of the eight gastropod species identified, three species (Cornu aspersum, Cantareus apertus and Rumina decollate) were classified as constant species. The Shannon–Weaver diversity and equitability indices vary by site. Conclusion The presence of certain species in one site and their absence in other sites, as well as the variation in ecological indices, could be attributed to the effect of soil-physicochemical factors.

Malacological news from the Czech and Slovak Republics in 2020

This paper presents important faunistic records including location data with all details conducted in the Czech and Slovak Republics during 2020. Four new non-native species, Arion intermedius, Ambigolimax valentianus, Clathrocaspia knipowitschii and Krynickillus melanocephalus, were recorded outdoors in Slovakia. Radix lagotis was genetically confirmed for the first time from several sites in the Czech Republic and Slovakia. Corbicula fluminea, recorded in Moravia for the first time in 2018, was found in another river, ca 50 km far from the first occurrence. Cepaea nemoralis, recorded in Slovakia for the first time in 2015, seems to have started spreading. New sites of Cornu aspersum were noticed in Prague and Bratislava; for the first time it was also found in Brno. There are also new records of several endangered species, e.g. Vertigo moulinsiana, Pisidium hibernicum, P. globulare, and Pseudanodonta complanata, presented.

The Influence of Temperature on the Larval Development of Aelurostrongylus abstrusus in the Land Snail Cornu aspersum

The metastrongyloid Aelurostrongylus abstrusus has an indirect lifecycle involving gastropod intermediate hosts. The widespread snail Cornu aspersum is an efficient intermediate host of A. abstrusus. As the temperature may influence the developmental rate of metastrongyloids from first (L1) to the third infective larval stage (L3) inside molluscs, this study evaluated the effect of two controlled temperatures on the development of A. abstrusus in C. aspersum. Overall, 300 snails were infected with 500 L1 of A. abstrusus and kept at ∼25 °C. Fifteen days post infection (D15), the overall developmental rate to L3 (0.8%) was assessed in a subset of 20 snails. The remaining gastropods were divided in 2 groups, i.e., 180 still kept at ∼25 °C (G1) and 100 hibernated at ∼4 °C (G2). On D30, the larval development was evaluated in 20 snails from each group, while another batch of 80 snails was selected random from G1 and hibernated at ∼4 °C (G3). The larval developmental rate was determined digesting 20 snails from each of the three groups on D45, D60, and D75. The higher mean developmental rate was registered in G1 (3.8%) compared to G2 (1.9%) and G3 (2.3%), indicating that the development to L3 of A. abstrusus in C. aspersum is positively influenced by the increase of temperature.

Impact of Ag Nanoparticles (AgNPs) and Multimicrobial Preparation (EM) on the Carcass, Mineral and Fatty Acid Composition of Cornu aspersum aspersum Snails

The hygienic practices on farms should reduce pathogenic microorganisms while simultaneously not harming the animals themselves; they must also not degrade the products’ quality. We assessed the effect of covering feed tables with paint containing silver nanoparticles (AgNPs) and the periodic spraying of effective microorganisms (EM) on production indicators and basic chemical composition, mineral content and fatty acid profiles in the bodies of Cornu aspersum aspersum snails. The animals were divided into four groups: (1) control, (2) with feed tables covered with AgNPs paint, (3) with EM spray applied and (4) with both factors—AgNP paint and EM spray. The highest increase in Ag, Zn, Fe and Ca retention, and the remodelling of the fatty acid profile in the carcasses of snails was found to be in the group of animals in contact with the feed tables covered with AgNP paint. In the group of animals exposed to the action of EM, an increased retention of Fe, Cu, P, Mg and Zn was found.

The protein and volatile components of trail mucus in the Common Garden Snail, Cornu aspersum

The Common or Brown Garden Snail, Cornu aspersum, is an invasive land snail that has successfully colonized a diverse range of global environments. Like other invasive land snails, it is a significant pest of a variety of agricultural crops, including citrus, grapes and canola. Cornu aspersum secretes a mucus trail when mobile that facilitates locomotion. The involvement of the trail in conspecific chemical communication has also been postulated. Our study found that anterior tentacle contact with conspecific mucus elicited a significant increase in heart rate from 46.9 to 51 beats per minute. In order to gain a better understanding of the constituents of the trail mucus and the role it may play in snail communication, the protein and volatile components of mucus trails were investigated. Using two different protein extraction methods, mass spectrometry analysis yielded 175 different proteins, 29 of which had no significant similarity to any entries in the non-redundant protein sequence database. Of the mucus proteins, 22 contain features consistent with secreted proteins, including a perlucin-like protein. The eight most abundant volatiles detected using gas chromatography were recorded (including propanoic acid and limonene) and their potential role as putative pheromones are discussed. In summary, this study has provided an avenue for further research pertaining to the role of trail mucus in snail communication and provides a useful repository for land snail trail mucus components. This may be utilized for further research regarding snail attraction and dispersal, which may be applied in the fields of agriculture, ecology and human health.