Search Results (43)

The study assesses water-filled subsidence basins in the Karviná region using ecological and faunistic characteristics, with freshwater molluscs as bioindicators. Two sites—subsidence lake Kozinec and Doubrava basins—differing in size, salinity, and vegetation, were examined. A malacological survey identified 16 mollusc species, with invasive species dominating Kozinec due to high salinity from mine water discharge, while native species prevailed in Doubrava basins. The study analysed the impact of shoreline zones on mollusc communities, measured physicochemical water parameters (e.g., salinity, pH, nitrites), and evaluated anthropogenic influences. Proposed measures include raising the dam to prevent salinisation of Kozinec’s isolated section, supporting ecological succession, and protecting littoral zones, highlighting the potential for revitalising post-mining sites. Full article

The genera: Lerniana Delicado et Hauffe, 2022, Trichonia Schütt, 1980, and two clades (“Radomaniola” elongata Radoman, 1973, and an unnamed clade referred to as “Radomaniola” sp. 1, sp. 2) whose assignment to any genus remains unknown, form sister group with the genus Radomaniola Szarowska, 2007 (Hydrobiidae W. Stimpson, 1865, subfamily Horatiinae D. W. Taylor, 1966). The paper deals with all these clades sister to Radomaniola. Cytochrome c oxidase subunit I (COI) sequences have been used to infer phylogenetic relationships between the snails collected at 15 localities in southern Greece and one in Montenegro. Thirty-two haplotypes represent eight Molecular Taxonomical Units (mOTUs) of the species level, four of them within the genus Lerniana: L. seminula (Frauenfeld, 1863), L. tritonum (Bourguignat, 1852), and two other of these four species are both described as new. First of them has been found at seven localities in Peloponnese, Attica and southern Thessaly, the second only at one locality, sympatrically with the former species. “Radomaniola” elongata does not belong to Radomaniola, and its relationships remain unknown, similarly as in other unnamed clade, whose genus-level assignment cannot currently be resolved. The shells, protoconchs, radulae, female reproductive organs and penes are presented, also for Trichonia trichonica Radoman, 1973, for which the genus assignment remains undecided based on our molecular results. The study clearly illustrates how fragmentary is our knowledge is on the real biodiversity of the minute truncatelloid gastropods, whose morphology—simple and variable—makes species distinction hardly possible. Informed decisions on species and habitat protection should consider the above. Full article

Caenogastropoda is a highly speciose and ecologically diverse subclass of Gastropoda but its higher order classification remains unclear, especially within its largest constituent group, Hypsogastropoda. Two nominal taxa encompassing most of the great diversity of Hypsogastropoda are in current widespread use: one is Latrogastropoda, which has been repeatedly redefined resulting in changes to the second, Littorinimorpha, which is generally not supposed to be monophyletic. We examined the utility of these divisions by assembling single-gene data sets of nuclear 28S ribosomal RNA (28S rRNA) and mitochondrial 16S ribosomal RNA (16S rRNA) and cytochrome c oxidase subunit I from many genera. Capuloidea was consistently found with strong support within Latrogastropoda, so this taxon is redefined here to include that superfamily. The analyses also suggested the redefinition of some superfamilies within Littorinimorpha, particularly for the clade comprising Truncatelloidea, Vanikoroidea and Rissooidea, and the Littorinoidea. Littorinimorpha was monophyletic (albeit lacking strong support) in the combined analysis of 28S rRNA and 16S rRNA and was resolved as the sister group of Latrogastropoda which was also monophyletic, with bootstrap support of 66%. Littorinimorpha was not monophyletic in other analyses. In these, the sister group of Latrogastropoda comprised clades of multiple littorinimorph superfamilies but these relationships were also not strongly supported. Full article

The Pécel loess–paleosol profile is a 25.72-metre-high well-preserved sequence in the northern part of Hungary. It was sampled every 4 cm for the purpose of sedimentological analysis and every 12 cm for the purpose of mollusc investigation, which are relatively high resolutions in loess investigation. Twenty samples were radiocarbon-dated from the L1 layer (top 8 m of the sequence). Subsequently, an age–depth model was constructed, from which an accumulation rate was calculated. Based on these radiocarbon and previous magnetic susceptibility data, the Pécel’s L1 layer is correlated with the Chinese Loess Plateau’s L1 layer and the MIS 2–4 stages. The malacological examinations show that the temperature was basically warm during the development, and there was open vegetation except on the S2, S1 and L1S1 paleosol layers, where significant forest expansion was shown. With the magnetic susceptibility and the malacological data, it is possible to track the changes in the conditions through the Chinese Loess Plateau’s timeline. Full article

Cephalopods have been widely studied around the globe. However, some areas are poorly understood. In Mexico, there is a significant lack of knowledge, particularly in the coastal zone of the eastern Pacific Ocean, where most studies have focused on commercial fisheries. An exhaustive review of documents (articles, books, theses, and regional reports) dealing with the cephalopods of the eastern Pacific in general and of Pacific Mexico in particular was undertaken along with an examination of malacological collections and databases available in Mexico and the USA. As a result, we obtained 3752 records corresponding to 3339 taxonomic records, featuring two superorders, six orders, 29 families, 60 genera, and 105 species. Of these, 89 species occurring in Mexican waters were confirmed, 76% pelagic, 21% in strictly benthic habitats, 2% benthopelagic, and 1% corresponding to demersal species. We proposed a modification for the distribution of 21 species and found 10 new records for Mexican waters. Full article

Microplastics (MPs) are contaminants of emerging concern, and the study of their effects on several species, especially freshwater organisms, has not been exhausted. Erpobdella johanssoni, a freshwater leech, was used as a model in this study for the assessment of the potentially toxic effects of polyethylene microplastics (PE-MPs) 40–48 µm in size under controlled laboratory conditions. PE-MP toxicity was assessed in the examined leech using four increasing concentrations (1, 10, 100, and 1000 µg/L) during an exposure period of 7 days. Oxidative damage was detected through the increase in malondialdehyde (MDA) levels, reflecting the occurrence of lipid peroxidation. The activities of enzymes involved in the antioxidant response, such as catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx), increased. Furthermore, the histopathology of the body wall, muscle cells, botryoidal cells, and ovaries was assessed to understand and evaluate the acute toxicity of PE-MPs. The histopathological changes detected in PE-MP-treated leeches varied in a concentration-dependent manner. Overall, this research indicated that even at environmentally relevant concentrations, PE-MPs had biological effects on the studied leeches and, consequently, on the freshwater invertebrate clade. This finding could provide novel insights into the effects of plastic pollution on freshwater ecosystems, particularly on invertebrate health and biodiversity. Full article

The malacological faunae of two algal habitats with different lighting conditions—a sciophilous wall and a photophilous one—both located in Tossa de Mar (Costa Brava, Girona, NE Spain), have been studied to examine the differences in the malacological communities, their distribution over time, and the role played by micromollusks in these algal habitats. Every two months, for a year, samples were collected via scuba diving and scraping standardized surfaces (20 × 20 cm) of the algal communities. In the laboratory, the samples were washed and filtered using two metal sieves (2 mm for coarse fraction and 513 µm for fine fraction). Mollusks were separated, identified, and later analyzed statistically to assess biodiversity indices and sample grouping. A total of 7913 mollusk specimens from 148 species (112 Gastropoda; 32 Bivalvia and 4 Polyplacophora) were identified across all samples, with 1669 specimens (84 species) from the sciophilous algae and 6244 specimens (133 species) from the photophilous algae. Moreover, 10 species accounted for 76.27% of the total abundance, with each species represented by over 100 specimens in the total samples. The gastropod Bittium latreillii was the most abundant species, with 2106 specimens recorded. Regarding the two fractions, 337 specimens (69 species) were found in the coarse fraction, while 7576 specimens (111 species) were found in the fine fraction. Significant differences were obtained between samples with respect to time, habitat type, and size fraction. The Shannon–Wiener biodiversity index values indicated differences between the two communities over time, as well as variations in biodiversity, with the photophilous community exhibiting higher values. It was demonstrated that algal thalli provide a highly suitable substrate for juvenile forms and micromollusks. Our findings, combined with the literature and various online citations, establish Tossa de Mar as the town on the Catalan coast with the best-documented malacological fauna. Full article

Arcangelo Scacchi (1810–1893) one of the greatest Italian geoscientists known worldwide, especially for his contributions in the fields of mineralogy and volcanology, dedicated his early years to malacological and zoological works. This paper aims to pay homage to a lesser-known side of the scientist, focusing on a malacological work related to fossils from his hometown, Gravina, in Puglia (southern Italy), located within the boundaries of the MurGEopark, which is aspiring to become a UNESCO Global Geopark (aUGGp), and at the border of Parco Nazionale dell’Alta Murgia (Alta Murgia National Park). Among others, Arcangelo Scacchi described 16 new species of molluscs but his precious collection, hosted in Naples, in the Real Museo Mineralogico (Royal Mineralogical Museum), now Museo di Paleontologia dell’Università di Napoli Federico II (Museum of Palaeontology of the University of Naples Federico II), was partly lost. In recent years, research has allowed the resampling of some species he described for the first time in 1835. Starting from this material, the figure of Scacchi was highlighted to the public through the temporal exhibitions and the use of 3D digital models of these resampled fossils. This activity represents: (i) a tribute to the first modern geoscientist who worked in the area of the MurGEopark, (ii) an instrument to preserve palaeontological remains of international importance, and (iii) a public opportunity to know this kind of geocultural heritage enriching the potential examples of (geo)dissemination in the MurGEopark. Full article

This study presents a comprehensive palaeoenvironmental reconstruction of the southern part of the Danube–Tisza interfluve in the Carpathian Basin from the Late Pleistocene to Early Holocene, addressing the region’s response to global climate forcings and local environmental factors based on multi-proxy analyses of two key protected areas: the Katymár brickyard and the hay meadows and loess banks of Hajós. By integrating radiocarbon-dated malacological, macrobotanical, pollen, phytolith, geochemical, and sedimentological analyses, it was possible to provide a picture of past climate–ecosystem interactions. The Katymár North sequence provides an extended chronology from Marine Isotope Stage 3 (MIS3, ca. 36,000 cal BP) through the Last Glacial Maximum (LGM) and into the Early Holocene, while the Hajós sequence offers high-resolution data for the LGM–Holocene transition. By the late Ice Age, humidity and surface moisture superseded temperature as primary palaeoecological limiting factors, promoting ecotone-like forest–steppe environments during cooling periods. Full article

The loess–paleosol profile of Máza brickyard in SW Hungary was investigated through multivariate analyses of malacofauna and sedimentological analyses. The aim was to reconstruct the complex developmental history of both sediment and malacofauna. Three age–depth models were calculated, and the best-fit model, the OxCal P-sequence, was chosen for further analysis. The profile overlays the MIS3 and MIS2, beginning at approximately 45,000–50,000 cal BP and ending at the Pleistocene/Holocene boundary. The accumulation rates were two periods of intensive accumulation, equal to those observed in the Bácska Loess Plateau in Hungary, and two periods of decreased accumulation. Between ~38,000 and 31,000 cal BP, a decreased accumulation period was observed in Máza and other profiles from the Bácska Loess Plateau, indicating a common weak accumulation period at the end of MIS3. Correspondence and cluster analyses provided a higher-resolution paleoecological reconstruction, revealing a more detailed picture of the evolution of the studied section. The presence of thermophilous gastropod species with a high contribution to the correspondence analysis was significant in the sections. Although Granaria frumentum, Helicopsis striata, Chondrula tridens, and Pupilla triplicata were not significant species in the Máza malacofauna as a whole, their presence was associated with warming periods and the emergence of open vegetation. Full article

Repeated sequences, especially transposable elements (TEs), are known to be abundant in some members of the important invertebrate class Gastropoda. TEs that do not have long terminal repeated sequences (non-LTR TEs) are frequently the most abundant type but have not been well characterised in any gastropod. Despite this, sequences in draft gastropod genomes are often described as non-LTR TEs, but without identification to family type. This study was conducted to characterise non-LTR TEs in neritimorph snails, using genomic skimming surveys of three species and the recently published draft genome of Theodoxus fluviatilis. Multiple families of non-LTR TEs from the I, Jockey, L1, R2 and RTE superfamilies were found, although there were notably few representatives of the first of these, which is nevertheless abundant in other Gastropoda. Phylogenetic analyses of amino acid sequences of the reverse transcriptase domain from the elements ORF2 regions found considerable interspersion of representatives of the four neritimorph taxa within non-LTR families and sub-families. In contrast, phylogenetic analyses of sequences from the elements’ ORF1 region resolved the representatives from individual species as monophyletic. However, using either region, members of the two species of the Neritidae were closely related, suggesting their potential for investigation of phyletic evolution at the family level. Full article

The artificially created Lake Pampulha, within the metropolitan area of Belo Horizonte, Minas Gerais State, lacks detailed information about its freshwater mollusks, representing a challenge for the assessment and conservation of this ecosystem. In this study, conducted during June and August 2021, we collected specimens on four different occasions and at five sampling points around the lake, using different sampling equipment, such as a shovel and a scoop. During these collections, we identified, enumerated and measured 1538 species of mollusks and additionally examined the presence of trematode larvae. We identified twelve species of fresh water bivalves and gastropods: Biomphalaria straminea, Biomphalaria kuhniana, Biomphalaria occidentalis, Drepanotrema cimex, Pomacea maculata, Stenophysa marmorata, Physa acuta, Gundlachia ticaga, Melanoides tuberculata, Pseudosuccinea columella, Omalonyx matheroni and Corbicula largillierti. Echinostome and strigeocercaria types of larval trematodes were detected in B. straminea. Notably, some species of mollusks have not previously been recorded at Lake Pampulha. The analyses revealed differences in the composition and abundance of species, highlighting the higher number of mollusk species in areas more impacted by human actions. This study expands our understanding of mollusk diversity at Lake Pampulha, and provides valuable data for longitudinal comparisons of water quality and considerations of the conservation of native species. Furthermore, it highlights the importance of choosing appropriate sampling equipment, depending on the research objectives. The presence of invasive species of medical and veterinary relevance as intermediate hosts of parasites reinforces the need for efficient environmental protection strategies to preserve this artificial, aquatic environment widely used by the local population and by tourists. Full article

Metastrongyloidea includes nematodes that parasitize mammals, mainly infecting their respiratory and cardiovascular systems, and are responsible for emerging zoonosis in the world. Terrestrial mollusks are their main intermediate hosts, with few exceptions. Here we present the results of a malacological survey to know the distribution of Angiostrongylus cantonensis in Macapá, Amapá, in the Brazilian Amazon region, after the report of a case of eosinophilic meningitis in 2018. Mollusks were collected in 45 neighborhoods between March 2019 and February 2020. They were identified, parasitologically analyzed, and their nematodes parasites were identified based on the morphology and MT-CO1 sequencing. Infections of An. cantonensis were observed in Achatina fulica, Sarasinula linguaeformis and Subulina octona. These are the first records of the natural infection of the last two species by An. cantonensis in the Brazilian Amazon region. The angiostrongylid Aelurostrongylus abstrusus, which parasitizes cats, was also detected parasitizing A. fulica and Diplosolenodes occidentalis. This is also the first record of the slug D. occidentalis infected by Ae. abstrusus. The highest infection rates were recorded in neighborhoods where the environment conditions favor the proliferation of both mollusks and rodents. The results demonstrate the ample distribution of An. cantonensis in Macapá and the need for surveillance and mollusk vector control in Brazil and other countries. Full article

The Rejtek I. Rock Shelter in the Bükk Mountains of the inner Western Carpathian region plays an important role in the Late Pleistocene and Holocene environmental historical analyses. The investigations of the cave sediment accumulated from the end of the Pleistocene and the recovered paleontological finds, together with the archaeological artefacts, provided an opportunity to develop stratigraphic classifications. In addition, by comparing archaeostratigraphic, lithostratigraphic and biostratigraphic data, it was possible to link environmental and prehistoric events. The importance of the site is shown by both the mollusc and floral cold- and warm-tolerant species that were present in the area during the Late Pleistocene. The early expansion of thermophilous species indicates the presence of a refuge already during the Late Pleistocene. Based on the documents of the excavation, the previous works, the sediment sequence, as well as the sediment samples and the filling material of the mollusc shells, together with the new chronology, we were able to clarify the relative order of the excavated layers and the description of the sediment types in the Rejtek I. Rock Shelter. Full article