Search Results (6)

Mucus trails are defining features of the class Gastropoda, which includes snails and slugs. While several studies have shown that mucus trails are followed by conspecifics, the detectable elements in the mucus have not been clearly identified. This is particularly relevant during periods of reproduction, whereby conspecific cues are critical for mate finding. A better understanding of the mucus’ molecular components, including proteins differentially represented between the reproductive and non-reproductive stages, could aid the development of novel eco-friendly biocontrol approaches. In this study, we investigated the mucus trails of the globally invasive land snail Cernuella virgata, which has become a significant pest to the grain industry. We conducted a comparative proteomic analysis of the non-reproductive- and reproductive-stage trail mucus, whereby 533 proteins were identified, including 191 and 226 stage-exclusive proteins, respectively. Subsequent comparative tissue transcriptomic analysis found that the albumen gland, which is the key gland for the preparation of fertilized eggs prior to egg laying, was the primary source of secreted proteins present in the reproductive stage trail mucus. This included leukocyte elastase inhibitors, achacin, perlucin, and other proteins without any known function (uncharacterized). In summary, our results strongly implicate the albumen gland as a source for snail trail mucus proteins deposited during the reproductive stage, suggesting a mechanism that could convey their reproductive status to conspecifics. Further research testing their bioactivity related to chemical communication is paramount and may assist in the development of a novel biocontrol strategy. Full article

Many terrestrial gastropod species have been dispersed as a result of anthropogenic activities and have adapted to new habitats where they are considered as alien or invasive species. Several synanthropic gastropods are invasive in urban and agricultural environments worldwide. In Saudi Arabia, increased human activities have accelerated the introduction of terrestrial gastropod species, increasing the need to study its gastropod fauna. Our preliminary survey disclosed the presence of ariophantid snails in a number of agricultural nurseries. Based on morphological features of shell, body, and reproductive system, we report the first record of Macrochlamys indica from Saudi Arabia. The phylogenetic analysis obtained from DNA sequences of the mitochondrial COI and 16S regions confirmed the identity of M. indica. One third of the investigated nurseries were infested with this snail, however, we did not find any specimens of M. indica in natural habitats or open agricultural fields. The snail-infested nurseries were distributed all over Saudi Arabia. The occurrence of one haplotype of partial mitochondrial COI sequence from these nurseries suggests that the introduction of M. indica is likely very recent. Based on the obtained results, it is recommended that control measurements must be implemented in order to eradicate or at least restrict the dissemination of M. indica from nurseries to natural habitats or agricultural fields. Full article

This paper is focused on selected units of casemates with enhanced fortification in the military fortification complex of the Czech borderlands landscape as specific forms of brownfields. They represent a functional system that interacts with surrounding nature, landscape character, and human society. Four approaches were chosen to study the function and potential of selected individual abandoned casemates with enhanced fortification, where each of them corresponds to one of the four landscape layers: genius loci, socio-economic sphere, functional relationship (between human and the landscape), and natural conditions. There is a corresponding research method for each of the landscape layers (guided interview with respondents, data analysis on abandoned casemates with enhanced fortifications as brownfields, analysis of their landscape functions, and zoological survey of interior). The main results could show that abandoned casemates with enhanced fortifications can play important roles in all landscape layers: stories and genius loci, abandoned casemates with enhanced fortification as a special type of military brownfield but also as a semi-natural ecosystem, and the same time as a habitat for invertebrates. The analyses and surveys conducted clearly demonstrate that abandoned casemates with enhanced fortification as units of military fortification complex of the Czech borderlands landscape perform several hidden important functions in the landscape for which they cannot be viewed as brownfields. This hidden functional potential is most likely best described by the concept of hidden singularity, which offers itself for integration into basic approaches to brownfields. Full article

Sequences of mitochondrial genes revolutionized the understanding of animal diversity and continue to be an important tool in biodiversity research. In the tribe Helicini, a prominent group of the western Palaearctic land snail fauna, mitochondrial data accumulating since the 2000s helped to newly delimit genera, inform species-level taxonomy and reconstruct past range dynamics. We combined the published data with own unpublished sequences and provide a detailed overview of what they revealed about the diversity of the group. The delimitation of Helix is revised by placing Helix godetiana back in the genus and new synonymies are suggested within the genera Codringtonia and Helix. The spatial distribution of intraspecific mitochondrial lineages of several species is shown for the first time. Comparisons between species reveal considerable variation in distribution patterns of intraspecific lineages, from broad postglacial distributions to regions with a fine-scale pattern of allopatric lineage replacement. To provide a baseline for further research and information for anyone re-using the data, we thoroughly discuss the gaps in the current dataset, focusing on both taxonomic and geographic coverage. Thanks to the wealth of data already amassed and the relative ease with which they can be obtained, mitochondrial sequences remain an important source of information on intraspecific diversity over large areas and taxa. Full article

Terrestrial snails that live in hot and dry climates have developed strategies to cope with high summer temperatures. Several species estivate during the warmest months of the years by resting on vertical supports, typically in groups. Understanding how snails choose their estivation sites and aggregate may lead to the development of new management tools in areas where these snails are invasive. Here, we investigated the preferences of four snail species for vertical supports varying in widths and heights under laboratory and field conditions, and tested whether the presence of conspecifics or snails of other species affected these preferences. The results show that the snails strongly preferred wider supports in laboratory dual-choice tests, and one species (Theba pisana) showed a consistent preference for taller supports as well. These results were confirmed in the field, where more snails were found on wider and taller supports 24 h after being placed in test quadrats. The percentage of snails found in groups on a support was strongly density-dependent. The presence of conspecifics or their mucus did not affect the choices of the snails, nor did the presence of snails of other species or their mucus. Taken together, these results could lead to the development of attractive supports that could be used to mass-capture snails in the field. Full article

The terrestrial land snail Theba pisana is circum-Mediterranean in native range and widely introduced and pestiferous in regions around the world. In California, USA, T. pisana has been recorded intermittently since 1914, but its source population(s) are unknown, and no morphological or molecular analyses within or between California populations have been published. Therefore, we compared molecular data (CO1, 16S, ITS2) and internal morphology (jaw, radula, reproductive system) in T. pisana collected from Los Angeles and San Diego counties in 2019–2020. DNA barcode (CO1 mtDNA) analysis revealed that T. pisana from Los Angeles County was most similar to T. pisana from the Mediterranean island of Malta, and northern San Diego County-collected specimens were most similar to T. pisana from Morocco. Morphology of the jaw and mucous glands also differed between Los Angeles and San Diego populations, but it is unclear if traits are lineage-specific or artifacts of ontogeny. Several pathways of introduction into Southern California are possible for this species, but evidence for intentional vs. accidental introduction of present populations is lacking. Subsequent investigation(s) could use the data generated herein to assess the provenance of T. pisana elsewhere in California and/or worldwide and inform analyses of reproductive biology and systematics in this widespread species. Full article