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Hausdorf, B., Xu, J., BAMBERGER, S. (2024) Repeated colonization of the Northern Limestone Alps from the Southern Limestone Alps by the rock‐dwelling snail species Cochlostoma henricae—Zoologica Scripta, 00, 000–000. The evolution of biogeographic disjunctions in the Southern and Northern Limestone Alps has been studied only in a few taxa. Cochlostoma henricae (Strobel, 1851) is a land snail species restricted to limestone rocks showing such disjunctions. We studied the phylogeny and population structure of this species using genomic ddRAD data to better understand the differentiation of the species in the Southern Alps and the origin of the isolated occurrences in the Northern Limestone Alps. Phylogenetic and population‐genetic analyses of the ddRAD data revealed a subdivision of the C. henricae populations into a western cluster and an eastern cluster. These clusters were probably separated by glaciers that extended from the Piave Valley to the margin of the Alps. Such a longitudinal subdivision is a common pattern of several species in the Southern Limestone Alps. However, the boundaries between western and eastern population groups differ between taxa. Cochlostoma henricae colonized the Northern Limestone Alps at least twice. The population from Breitenwang in Tyrol originated from the western group, whereas the occurrences in the Salzkammergut are from the eastern group. These and similar disjunctions of several other land snails show that even species with limited dispersal abilities could cross the Alps repeatedly by passive long‐distance dispersal events. A subdivision of C. henricae into three subspecies, proposed based on shell characters, does not correspond to its population‐genetic structure. Instead, the eastern and western population groups represent distinct evolutionary units. [ABSTRACT FROM AUTHOR]

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Prey alter their foraging when threatened by predators. Two mutually inclusive hypotheses explain this response. The first entails that defence behaviours to minimise exposure to predators prevent prey from achieving their preferred diet, while the second postulates that prey deliberately change their diet to fulfil new stress‐induced nutritional demands. We combined field observations and laboratory experiments to determine which hypothesis dictates snail dietary responses to risk of beetle predation. Snails exposed to predation‐risk reduced activity, increased climbing, increased respiration, ate distinctively to achieve a certain nutrient target, and preferred eating on the cage floor at the costs of nutritional imbalance and elevated risk. When only carbohydrates‐rich food was on the floor, stressed snails reduced activity and foraged less, but when only protein‐rich food was on the floor snails increased activity and consumed more carbohydrates than their no‐risk conspecifics. This outcome suggests that nutrient accessibility may determine which hypothesis governs the prey dietary reaction to predation risk. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

This study aims to investigate the reproductive characteristics of Cernuella virgata (Da Costa, 1778) from Diyarbakır, Southeast Turkey. From October 2023 to February 2024, the reproductive activities of over 300 individuals were monitored in Yeniköy Cemetery in Diyarbakır. The snails were first observed mating on 18 October 2023, after the autumn rains, with the first egg laying observed on 3 November 2023. The last mating observation occurred on 8 January 2024. A total of 225 individuals were noticed mating during this period. The number of eggs per clutch ranged from 36 to 114, with an egg hatching time between 18 and 32 days. Eggs were deposited amidst damp mosses, beneath decomposing vegetation, or on the damp soil surface. The spawning period lasts 12–13 weeks. Egg weights varied from 0.60 to 1.20 mg, and egg diameters ranged from 1.10 to 1.42 mm. Hatchling snails had shells with 1.5–2 whorls (protoconch), weighing between 1.15 and 1.72 mg on. The height of the hatchling’s shells ranged from 0.75 to 0.94 mm, and the width ranged from 1.21 to 1.38 mm. This study offers a detailed insight into the reproductive biology of C. virgata and marks the first record of the species in the region. [ABSTRACT FROM AUTHOR]

The freshwater snails and mussels are recognized as ecosystem engineers owing to their ability to influence the ecological processes. We investigated the effect of the snail Filopaludina bengalensis and the mussel Lamellidens marginalis alone and in interaction with the macrophyte Lemna minor on the ecological processes (nutrient dynamics, microbial account, sediment properties and periphytic algal growth) of the freshwater ecosystem through a mesocosm experiment. Both the snail and mussel promoted the growth rate of L. minor; however, the presence of snail negatively influenced the growth of periphyton. The biogeochemical process was affected by the presence of snails and mussels. Macrophyte association further influenced this biogeochemical process. Snail and mussel enhance the growth of heterotrophic bacteria and phosphate solubilising bacteria in the sediment. Likewise, the presence of macrophyte also positively influences the microbial growth. The activities of the benthic fauna like the mussels and the snails can be considered a useful process for the sustenance of the microbes and the macrophytes representing a pattern of bottom-up regulation. [ABSTRACT FROM AUTHOR]

Herbivorous invaders promote changes in community structure and ecosystem functioning. The apple snail, Pomacea canaliculata, is an invader with strong impacts on wetland vegetation and aquatic crops. While able to feed on diverse trophic resources using different feeding mechanisms it is usually regarded as a macrophytophage. However, studies showing direct evidence of what they actually eat in natural waterbodies are few and their results do not fully support such a feeding habit. We analyzed the digestive contents of P. canaliculata using a micrographic technique to describe the spatiotemporal variation of its natural diet within its native range. Stomach and intestine contents were similar but the intestines were never empty and their volume and diversity were generally higher. Detritus was the dominant food item (84.1% of total abundance) and was consumed by all the snails whereas macrophytes were eaten by only half of the snails and represented only an 8.6% of total abundance; filamentous algae, animal remains and grasses showed lower than 5% of total abundance. The spatiotemporal variation in these feeding patterns was minor, despite the among site variation in macrophyte coverage and richness. In the Encadenadas del Oeste basin, P. canaliculata behaves as a specialist on detritus, with some individuals occasionally consuming other resources and can thus be described as an opportunistic generalist omnivore. The impacts of apple snail invasions on both detritus and on other detritivores have seldom been studied although they may have important negative and positive effects, respectively, on dead vegetal matter decomposition. [ABSTRACT FROM AUTHOR]

The excess of contaminating metals in the aquatic environment and their easy absorption by mollusks and other organisms prompts interest in evaluating metal toxicity associated with environmental variables. This study aimed to determine if temperature variations influence lead (Pb) toxicity in the hemocytes of the gastropod Pomacea canaliculata. We performed in vitro assays, including lysosomal integrity, mitochondrial activity, cell morphology, cell volume, and diagnosis of cell death pathways (apoptosis and necrosis). Hemocytes exposed to a concentration of 0.01 mgL−1 of Pb at 11 °C showed increased mitochondrial activity. In addition, at temperatures of 11 °C and 15 °C, we also observed increased mitochondrial activity at the concentration of 1.0 mgL−1 of Pb. Furthermore, we observed an increase in the frequency of spherical cells at the concentration of 0.1 mgL−1 of Pb at a temperature of 11 °C. The actions of lead and temperature did not affect the other parameters analyzed. Although most parameters indicate resistance, cytotoxic effects can be detected in the hemocytes of P. canaliculata. [ABSTRACT FROM AUTHOR]

In this work, we present an integrative revision of the Lymnaeidae from the northeastern margin of Asia (Far East Russia, Japan, and Korea) and Alaska. According to our results, 14 native species inhabit this region, belonging to eight genera in two subfamilies (Lymnaeinae: Dallirhytis , Galba , Walhiana , Ladislavella , and Lymnaea ; and Amphipepleinae: Kamtschaticana , Orientogalba , and Radix). Four of these species are new to science and three of them are described in this paper. Additionally, three established alien species are recorded from Japan (Pseudosuccinea columella , Galba schirazensis , and Galba humilis). The Japanese Archipelago represents an evolutionary hotspot of pond snail diversity, encompassing seven native species, three of which are endemic. The faunal connections between North America and northeastern Asia are discussed in the context of historical biotic interchange across the Beringian Land Bridge. Two cold-tolerant pond snails share high-latitude but localized ranges, being endemic to the Beringian Arctic: Dallirhytis atkaensis (Chukchi Peninsula, Alaska, and Aleutian Islands) and Walhiana arctica comb. nov. (Alaska). Our findings indicate that the Beringian Land Bridge has played a role in freshwater faunal exchanges between northeastern Asia and western North America. [ABSTRACT FROM AUTHOR]

Studying the effect of heating rate on upper thermal limit has gained considerable attention in enhancing our mechanistic understanding of how organisms respond to changing temperatures in the context of climate change. The present study aimed to investigate the effects of heating rate on upper thermal limit and understand the physiological and molecular mechanisms used by organisms to cope with thermal stress at different heating rates. Batillaria attramentaria snails were exposed to slow (3°C/h) or fast (9°C/h) heating rates. The median lethal temperature (LT50) of snails exposed to these varying heating rates was determined. Additionally, we assessed heart rate under constant heating and investigated the transcriptomic response at the temperature where the heart rate reaches zero (FLT). The results revealed that snails exhibit a higher upper thermal limit (approximately 1.5°C) during fast heating as compared to slow heating. On average, the heart rate of slowly heated snails was 11 beats per minute lower than that of fast heated snails when the temperature was below 45°C. The findings indicate that the metabolic rate is lower during slow heating compared to fast heating when subjected to the same level of thermal stress. When exposed to a temperature of FLT, snails initiated a typical heat shock response to thermal stress, which included the increased expression of genes encoding heat shock proteins (HSPs) and protein disulfide isomerase (PDIA5) involved in protein folding. Remarkably, the genes glucoseregulated protein 94 (GRP94) and Calnexin, which are associated with the binding of unfolded proteins, showed distinct up-regulation in snails that were heated slowly, indicating the accumulation of misfolded proteins. The accumulation of misfolded proteins, coupled with additional energy consumption, may contribute to the lower upper thermal limit observed at a slow heating rate. Our research provides valuable insights for determining the realistic upper limits of temperature tolerance and improving predictions of how organisms will be affected by climate change in the future. [ABSTRACT FROM AUTHOR]

The ecotoxicological consequences of azoxystrobin on land snails have not yet been addressed. Therefore, the present study aims to provide novel data on the threat of a commercial grade azoxystrobin (AMISTAR) at two environmentally relevant concentrations (0.3 µg/ml) and tenfold (3 µg/ml) on the model species, Theba pisana by physiological, biochemical, and histopathological markers for 28 days. Our results showed a reduction in animal food consumption and growth due to exposure to both azoxystrobin concentrations. It also induced oxidative stress and led to a significant decrease in lipid peroxidation (LPO) levels after 7 days of exposure, while the opposite effect occurred after 28 days. Except for the 7-day exposure, all treated snails had significantly reduced glutathione (GSH) content and increased catalase (CAT) activity at all-time intervals. Glutathione peroxidase (GPx), glutathione-S-transferase (GST) activities, and protein content (PC) were elevated in treated snails at all-time intervals. Moreover, alterations in acetylcholinesterase (AChE) activity between a decrease and an increase were noticed. Additionally, azoxystrobin exerted changes in T. pisana hepatopancreas architecture. Our study suggests that azoxystrobin may have negative ecological consequences for T. pisana and highlights its potential risks to the natural environment. [ABSTRACT FROM AUTHOR]

Background: Angiostrongyliasis is a zoonotic parasitic disease caused by the rat lungworm Angiostrongylus cantonensis. The intermediate hosts of A. cantonensis are gastropods, and snail species such as Pomacea canaliculata play a key role in the transmission of human angiostrongyliasis. Detecting A. cantonensis infection in snails is an important component of epidemiological surveillance and the control of angiostrongyliasis. Methods: In this study, a new method for diagnosing A. cantonensis infection in gastropods was developed by recovering larvae from the buccal cavity of three snail species. The entire buccal cavity of a snail was extracted, and the tissue was pressed between two microscope slides to observe whether A. cantonensis larvae were present. Our new method was compared with traditional pathogenic detection methods of lung microscopy, tissue homogenization, and artificial digestion. We artificially infected 160 P. canaliculata, 160 Cipangopaludina chinensis, and 160 Bellamya aeruginosa snails with A. cantonensis. Then, the four different detection methods were used to diagnose infection in each snail species at 7, 14, 21, and 28 days post exposure. Results: We found no significant difference in the percentages of infected P. canaliculata snails using the four methods to detect A. cantonensis larvae. The radula pressing method had a mean detection rate of 80%, while the lung microscopy (81.3%), tissue homogenization (83.8%), and artificial digestion (85%) methods had slightly greater detection rates. Similarly, the percentages of infected C. chinensis snails that were detected using the radula pressing (80%), tissue homogenization (82.1%), and artificial digestion (83.8%) methods were not significantly different. Finally, the percentages of infected B. aeruginosa snails that were detected using the radula pressing (81.3%), tissue homogenization (81.9%), and artificial digestion (81.4%) methods were not significantly different. These results showed that the radula pressing method had a similar detection rate to traditional lung microscopy, tissue homogenization, or artificial digestion methods. Conclusions: This study demonstrates a new method for the qualitative screening of gastropods that act as intermediate hosts of A. cantonensis (and other Angiostrongylus species), provides technical support for the control of human angiostrongyliasis, and furthers research on A. cantonensis. [ABSTRACT FROM AUTHOR]

This study describes the process of Pomacea patula catemacensis grow-out in outdoor tanks. Experimental juvenile snails (1.5-2 months old) obtained from wild breeding snails were reared using a recirculating aquaculture system (RAS). The present study focused on increasing the surface area of growth tanks to be used by snails without affecting their growth and survival by adding shelters throughout the water column, which also worked to harbor snails. Two treatments were tested; T1: shelters made with curved clay tiles, T2: curved PVC shelters, and control (without shelters) in triplicate. The stocking density was set at 420 ind m-2 in tanks with 1 m³ total volume, and the culture period was 150 days. The final weight of the snails was significantly higher in control and PVC shelter groups (9.14 ± 2.2 and 8.83 ± 2.31 g, respectively), with PVC shelters showing the highest productivity in total biomass (12.03 ± 0.86 kg tank-1, P < 0.05). Final survival (%) was not significantly different among treatments (56.49 ± 1.62 to 58.05 ± 0.62). [ABSTRACT FROM AUTHOR]

The photoperiodic mechanism distinguishes between long and short days, and the circadian clock system is involved in this process. Although the necessity of circadian clock genes for photoperiodic responses has been demonstrated in many species, how the clock system contributes to photoperiodic mechanisms remains unclear. A comprehensive study, including the functional analysis of relevant genes and physiology of their expressing cells, is necessary to understand the molecular and cellular mechanisms. Since Drosophila melanogaster exhibits a shallow photoperiodism, photoperiodic mechanisms have been studied in non-model species, starting with brain microsurgery and neuroanatomy, followed by genetic manipulation in some insects. Here, we review and discuss the involvement of the circadian clock in photoperiodic mechanisms in terms of neural networks in insects. We also review recent advances in the neural mechanisms underlying photoperiodic responses in insects and snails, and additionally circadian clock systems in snails, whose involvement in photoperiodism has hardly been addressed yet. Brain neurosecretory cells, insulin-like peptide/diuretic hormone44-expressing pars intercerebralis neurones in the bean bug Riptortus pedestris and caudo-dorsal cell hormone-expressing caudo-dorsal cells in the snail Lymnaea stagnalis, both promote egg laying under long days, and their electrical excitability is attenuated under short and medium days, which reduces oviposition. The photoperiodic responses of the pars intercerebralis neurones are mediated by glutamate under the control of the clock gene period. Thus, we are now able to assess the photoperiodic response by neurosecretory cell activity to investigate the upstream mechanisms, that is, the photoperiodic clock and counter. [ABSTRACT FROM AUTHOR]

Understanding how climate and local stressors interact is paramount for predicting future ecosystem structure. The effects of multiple stressors are often examined in small‐scale and short‐term field experiments, limiting understanding of the spatial and temporal generality of the findings. Using a 22‐year observational dataset of plant and grazer abundance in a southeastern US salt marsh, we analyzed how changes in drought and grazer density combined to affect plant biomass. We found: (1) increased drought severity and higher snail density both correlated with lower plant biomass; (2) drought and snail effects interacted additively; and, (3) snail effects had a threshold, with additive top‐down effects only occurring when snails were present at high densities. These results suggest that the emergence of multiple stressor effects can be density dependent, and they validate short‐term experimental evidence that consumers can augment environmental stress. These findings have important implications for predicting future ecosystem structure and managing natural ecosystems. [ABSTRACT FROM AUTHOR]

Monachoides is a genus of medium‐sized European land snails in the family Hygromiidae. Systematics of this family was until recently based on traits of the genital system that were shown to be uninformative, resulting in revisions of classifications at the genus and family levels. Up to six species were recognized in Monachoides lately, but the inclusion of three of these species was questionable. Our phylogenetic analysis and morphological examinations show that the genus includes species previously classified in two different Hygromiidae subfamilies. After transferring three Balkan species to the unrelated genus Xerocampylaea, Monachoides emerged as a group that diversified relatively northerly, at the boundary between the Balkans and Central Europe. One species, Monachoides bacescui, is synonymized here and a previously overlooked one is redescribed, leaving only three valid species in Monachoides as currently understood: M. incarnatus, M. vicinus and M. welebitanus. These can be distinguished from other hygromiid species by their distinctive microsculpture of the shell surface, which also allows for identification of juveniles or fragmented fossil material. However, the clade comprising the three above species was found to also include the two species currently classified in Perforatella. As a result, the two genera are synonymized, with Perforatella having priority. [ABSTRACT FROM AUTHOR]

As ecosystem disruptors and intermediate hosts for various parasites, freshwater snails have significant socioeconomic impacts on human health, livestock production, and aquaculture. Although traditional molluscicides have been widely used to mitigate these effects, their environmental impact has encouraged research into alternative, biologically based strategies to create safer, more effective molluscicides and diminish the susceptibility of snails to parasites. This review focuses on alterations in glucose metabolism in snails under the multifaceted stressors of parasitic infections, drug exposure, and environmental changes and proposes a novel approach for snail management. Key enzymes within the glycolytic pathway, such as hexokinase and pyruvate kinase; tricarboxylic acid (TCA) cycle; and electron transport chains, such as succinate dehydrogenase and cytochrome c oxidase, are innovative targets for molluscicide development. These targets can affect both snails and parasites and provide an important direction for parasitic disease prevention research. For the first time, this review summarises the reverse TCA cycle and alternative oxidase pathway, which are unique metabolic bypasses in invertebrates that have emerged as suitable targets for the formulation of low-toxicity molluscicides. Additionally, it highlights the importance of other metabolic pathways, including lactate, alanine, glycogenolysis, and pentose phosphate pathways, in snail energy supply, antioxidant stress responses, and drug evasion mechanisms. By analysing the alterations in key metabolic enzymes and their products in stressed snails, this review deepens our understanding of glucose metabolic alterations in snails and provides valuable insights for identifying new pharmacological targets. [ABSTRACT FROM AUTHOR]

Snails are the first intermediate host in the life cycle of trematodes. Previous research found that Trichopodus microlepis fish, cultured in earthen ponds in Tan Nhut Commune, Binh Chanh District, Ho Chi Minh City, Vietnam had a high infection rate with metacercariae of Centrocestus formosanus and Procevorum sp. It is necessary to investigate whether habitats supplying water to the ponds may contribute to the transmission by carrying intermediate hosts and/or cercariae into these ponds or not. A study of cercariae and snail composition in rice fields and canal supplying water directly to these Trichopodus microlepis ponds was carried out with six samplings in the years 2022 and 2023. A total of 1,151 snails were collected, and nine snail species belonging to 8 genera and 6 families were identified. Three snail species in both rice fields and canal were infected with trematode (cercariae stage) including Bithynia siamensis, Lymnaea viridis and Indoplanorbis exustus. The overall prevalence in the dry season (25.9%) was significantly higher than in the wet season (10.6%) (P<0.05). Three cercariae morphotypes were recovered from snails: xiphidio (in all three snails), echinostome (in Lymnaea viridis and Indoplanorbis exustus), and pleurolophocercous in Bithynia siamensis. This finding shows that Bithynia siamensis is one of the infected sources for Trichopodus microlepis fish cultured in ponds, as pleurolophocercous is also the cercariae in the family of Heterophyidae (including Centrocestus formosanus and Procevorum sp.). Further research should be done to clarify the transmission of fish-borne zoonotic diseases to cultured Trichopodus microlepis in other habitats including the actual fishponds, and sources of trematodes in order to produce Trichopodus microlepis free of metacercariae, contributing to clean aquaculture development and safe food for local people in the area. [ABSTRACT FROM AUTHOR]

Background: One of the pests that can be detrimental to crops in agroecosystems is the land snail, also known as Monacha cartusiana. Molluscicides that are chemical are the first line of defense against land snails; however, because of their toxicity to both land and aquatic life, there has been an increase in interest in the discovery of biological molluscicides that are acceptable and ecofriendly. These molluscicides are a natural and environmentally safe alternative to synthetic poisons. Methods: The purpose of this study is to examine the efficacy of animal bile liquid against Monacha cartusiana in vitro. Molluscicides were tested using a dipping approach on snails isolated from agricultural land. PBS was utilized as a control. Furthermore, four different concentrations of extract (12.5, 25, 50 and 100%) were evaluated across different periods, and changes in snail viability were recorded (5, 10, 20 and 40 minutes). A chemical analysis was carried out using GC-MS to determine the presence of numerous expected active chemical components in animal bile fluids. Result: The results clear that the bile had significant efficacy in killing snails at 100%, 61%, 41% and 20% after 20 hours. The findings suggest that bile contains potent chemicals and is a promising strategy for molluscicide. More research is needed to identify the specific active compounds found in animal bile, as well as their modes of action and application in vivo. [ABSTRACT FROM AUTHOR]

In recent years, there has been a growing interest in exploring novel natural sources for antioxidant and anti-inflammatory agents, driven by the need for alternative therapeutic strategies with fewer side effects. This study investigates the potential of the Biomphalaria alexandrina snail as a valuable model organism to evaluate the antioxidant and anti-inflammatory properties of Sarcophaga argyrostoma larval hemolymph. The choice of B. alexandrina snails as a model is based on its ecological relevance and physiological similarities to other organisms, supporting well-established use in ecological and physiological research, as well as it provides a valuable platform for such investigations. Ultimately, this study may open avenues for the development of innovative and sustainable therapeutic interventions rooted in the rich biodiversity of the natural world. The experimental design involves the extraction of hemolymph from S. argyrostoma larvae, followed by a comprehensive analysis of its antioxidant capacity and anti-inflammatory effects using adult snails. Various biochemical assays, including total antioxidant capacity, immunomodulatory markers and histological investigation, will be employed to assess the bioactive potential of the hemolymph. The outcomes of this research can be attributed to the identification of the anti-oxidant and anti-inflammatory effects of hemolymph. This effect was observed through the reduction of oxidative stress and proinflammatory mediators, impacting the biological activities of the snails. The study is the first to shed light on the potential benefits of S. argyrostoma larval hemolymph using an animal model, showcasing its ability to mitigate oxidative and inflammatory responses within the biological context of the snails. [ABSTRACT FROM AUTHOR]

The systematic review and meta-analysis were conducted to determine the estimates of the prevalence and infection rates of natural and experimental infections of amphistome species in intermediate host snails (IHs) across different continents. A search of peer-reviewed literature on natural and experimental infections of freshwater snails with amphistome species was conducted from four electronic databases from 1984 to 2023. The estimates of the prevalence and/or infection rates were based on 36 eligible peer-reviewed articles, which met the inclusion criteria and reported on natural and experimental infections of amphistome species in freshwater snails. The results showed that a total of 1,67,081 snail species from the peer-reviewed articles were examined for natural infections and 7,659 snail species for experimental infections. The overall pooled prevalence of amphistome infections from naturally infected snails was 2% (95% CI: 0–4), while the overall pooled prevalence of amphistome infections from infections was 40% (95% CI: 18–64). The highest pooled prevalence of natural infection was 3%, which was recorded in Europe (95% CI: 1–7%). The highest overall prevalence of naturally infected amphistome was 6% (95% CI: 0–20%) for Paramphistomum epiclitum. The Americas had the highest pooled prevalence of experimental amphistome infection among freshwater snails (66%; 95% CI: 26–96%). The highest pooled infection rate of 65% (95% CI: 12–100%) was recorded for Paramphistomum cervi in experimental infections. Galba truncatula was the only snail that qualified for meta-analysis for natural infection with Calicophoron daubneyi, with a pooled prevalence of 3% (95% CI: 1–8%). Galba truncatula infected with C. daubneyi and P. cervi, and Bulinus tropicus infected with Calicophoron microbothrium in the experimental infection qualified for the meta-analysis, with an overall infection rate of 66% (95% CI: 34–92%) and 30% (95% CI: 0–74%), respectively. The pooled prevalence of amphistome species infection in the intermediate host (IH) snails based on detection techniques was higher with PCR compared to the dissection and shedding of cercariae. The results from the quality effects model revealed a high heterogeneity and publication bias between studies. This meta-analysis provided valuable insights into the prevalence and infection rates of amphistome species in snail IHs across different geographical regions. [ABSTRACT FROM AUTHOR]

It became necessary to employ safer and more efficient alternatives to plant pathogenic bacteria and land snails control due to the growing issues these snails and bacteria were causing on various crops. Green nanoparticles have been used because of their stability, low-cost feasibility and antimicrobial characteristics and snails. The current work intends to investigate the effectiveness of green synthetic silver and iron oxide nanoparticles of an aqueous extract of Acacia nilotica pods Ag-NPs (AEANP-AgNPs) and FeO-NPs (AEANP-FeONPs) against two identified plant pathogenic bacterial strains (Xanthomonas euvesicatoria and Pseudomonas syringae pv. tomato) and to land snails (Monacha cartusiana and Eobania vermiculata) collected from sandy loam soil. AEANP-AgNPs and AEANP-FeONPs were made and characterized using a TEM, Zeta potential, FTIR and EDX. Different concentrations of AEANP-AgNPs (1700, 3400, and 5100 ppm) and AEANP-FeONPs (2700, 5400, and 8100 ppm) were tested. The concentration (5100 ppm) of Ag-NPs was higher in the inhibition against P. syringae pv. tomato while (5400 ppm) and (8100 ppm) concentrations of FeO-NPs were equal to inhibition against X. euvesicatoria. In planta, the treated strain of X. euvesicatoria exhibited low severity while the treated strain of P. syringae pv. tomato didn't exhibit a significant difference severity. So, M. cartusiana snails were more sensitive to the toxic effect of Ag-NPs and FeO-NPs than adult snails, E. vermiculata. The mortality for adult snails was increased with increasing concentration of both nanoparticles. The LC50 concentrations of Ag-NPs for adult snails M. cartusiana and E. vermiculata were (1.885×103and 7.618×10³) and (4.066×10³ ppm and 10.776×10³ ppm) for FeO-NPs respectively. [ABSTRACT FROM AUTHOR]

Introduction. Abdominal and neural angiostrongyliasis caused by Angiostrongylus costaricensis and A. cantonensis, respectively, are zoonotic diseases involving snails as intermediate hosts. Colombia has already reported human cases, and the increasing distribution of Lissachatina fulica and Cornu aspersum raises public health concerns due to the potential risk of disease transmission in areas where parasites and hosts coexist. Objective. To identify the presence of Angiostrongylus spp. in snail species L. fulica and C. aspersum in Antioquia, Colombia. Materials and methods. This prospective cross-sectional study had a population of 5,855 L. fulica and C. aspersum snails captured in the ten towns of the Valle de Aburrá (Antioquia, Colombia), 169 samples were collected in 28 sampling points. Lung tissues of the collected snails were dissected and analyzed to detect Angiostrongylus spp. through molecular techniques. Results. Angiostrongylus spp. were identified in both L. fulica and C. aspersum. Angiostrongylus costaricensis was detected in 18 pooled prevalence of 30% (95% CI = 19.2-43.3), and Medellín was the municipality with the highest number of positive samples (33.3%). Seventy-two-point-two percent of the positive places reported the presence of rodents. None of the tests were positive for A. cantonensis. Conclusion. Our findings provide important insights into the epidemiology and distribution of Angiostrongylus spp. in Antioquia, Colombia. The identification of these parasitic nematodes in L. fulica and C. aspersum highlights the potential role of these snails as intermediate hosts in the transmission of Angiostrongylus spp. infections in the Valle de Aburrá, with implications for human and veterinary health.

Heliciculture is a branch of animal husbandry that deals with cultivation and using edible terrestrial snails for food and cosmetic purposes. This type of animal husbandry has an advantage over others in terms of simplicity of technology, as snails do not require complex technical equipment and care. In addition, they are unpretentious in feeding and resistant to diseases. Heliceculture has signifcant potential for development in Ukraine, as there is already considerable demand for snails in the food and cosmetics market. This industry is also developing rapidly and becoming increasingly popular among farmers and businessmen worldwide. At the same time, achieving success in snail farming requires specifc knowledge and skills. For example, it is essential to choose a suitable cultivation method, ensure optimal keeping and feeding conditions, and adhere to the standards of product storage and processing. It is also worth considering the specifcs of the legislation regulating the breeding and circulation of snails and the possible risks associated with pollution and animal diseases. An essential aspect of the development of helicopter culture is research and development to improve the quality and quantity of products, as well as the technology for reproduction and keeping snails. Such research should help improve efciency and make the industry more competitive. Exploring opportunities to improve the efciency of nutrient use in snail feed can signifcantly increase the proftability of production. Enzyme preparations are widely used in heliceculture to enhance the digestion of complex compounds, reduce the negative impact of anti-nutrients, and improve feed conversion. The use of such products in heliculture is reasonable and can have a positive impact on production efciency. The direction of complex feeding in heliceculture has not been studied much, and the influence of this cellulolytic drug on the productive qualities of Helix Aspersa Maxima species snails has yet to be clarifed. The results obtained during the study can substantiate the positive aspects of using special preparations to increase snail cultivation efciency and the use of nutrients in the diet. The study was conducted to investigate the effect of cellulosolytic enzyme preparation «AGROCELL» on the productivity of snails of the species Helix Aspersa Maxima. The results of the work showed that the addition of the enzyme preparation «AGROCELL» to the diet increases the absolute increase in live weight of snails by 1.2 g and the chain weight by 0.1-1.1 g.

Schistosoma mansoni worms cause a waterborne parasitic disease called schistosomiasis. It commonly affects individuals in lack of sanitation structure. In Brazil, Pará state has Belém as one of the worst sanitation-ranking places in 2023, where schistosomiasis transmission was already documented. This study reports the occurrence of schistosomiasis in residents of Ilha das Onças, an island next to Belém. Stool samples were obtained from participants over 2 years old, all residents from Furo do Rio Grande, one of the rivers on the island. The Kato-Katz technique was performed for parasite investigation in the stool samples. Each participant responded to a sociodemographic and clinical questionnaire. The residences were georeferenced for map designing. Three out of 263 participants were S. mansoni positive, all men, ages ranging from 19 to 41 years old, with low parasitic load. Malacological surveys were carried out, but no Biomphalaria snails were found. Risk factors for schistosomiasis establishment are present on the island, and the lack of sanitation makes it a potential risk area. Malacological surveys are highly encouraged as preventive measures, as well as health surveillance for riverside populations, generating data that will help health authorities in the management and planning of preventive control actions. HIGHLIGHTS The study revealed the presence of Schistosoma mansoni infection in residents of Ilha das Onças.; The area had no previous reports of the disease.; Only male individuals tested positive for the infection.; No Biomphalaria snails were found in the peridomestic area of infected individuals.; Environmental conditions might enable schistosomiasis establishment on the island.;

Relevanse. The article presents information about actively spreading potential pests of agricultural crops in the Central region of the Russian Federation – slugs and snails – invertebrates belonging to the genus of gastropods. The harmfulness of these pests is manifested in a decrease in the size of the crop, a decrease in its quality, loss of marketability and fruit keeping. The most seriously affected in this regard are the planting of cabbage, lettuce, peas, turnips, potatoes and cucumbers. Snails and slugs can serve as a source of infectious diseases, various fungal spores, bacteria and parasitic helminths are often carried with the mucus produced by their bodies, which often pose a threat to the health of people and pets.Methods. Visual surveys were carried out to determine the number of pests in the field and in the adjacent territory in the conditions of the Moscow region (Lyubertsy city district). The studies were conducted in accordance with officially approved methods. Data on the species composition of pests are analyzed. The possibility of active harmful activity and potential threat of gastropods in a changing climate and their adaptation in the conditions of the Central region of the Russian Federation is considered.Results. According to the results of the conducted research, it was found that in vegetable gardens and private farms, grape snail and arable slug are most often found, in potato plantings – field (arable slug). Recommendations on slug and snail control in the private sector and farms are given.

Colorectal cancer (CRC) is the third most common malignancy cause of cancer-related mortality worldwide. Epithelial-mesenchymal transition (EMT) promotes cancer metastasis and a tumour-based Glasgow EMT score was associated with adverse clinical features and poor prognosis. In this study, the impact of using the established five tumour-based EMT markers consisting of E-cadherin (E-cad), β-catenin (β-cat), Snail, Zeb-1, and Fascin in combination with the stromal periostin (PN) on the prediction of CRC patients' prognosis were invesigated. Formalin-fixed paraffin-embedded tissues of 202 CRC patients were studies the expressions of E-cad, β-cat, Snail, Zeb-1, Fascin, and PN by immunohistochemistry. Individually, cytoplasmic Fascin (Fc), cytoplasmic Snail (Sc), nuclear Snail (Sn), stromal Snail (Ss), and stromal PN (Ps) were significantly associated with reduced survival. A combination of Ps with Fc, Fs, and Sn was observed in 2 patterns including combined Fc, Fs, and Ps (FcFsPs) and Fc, Sn, and Ps (FcSnPs). These combinations enhanced the prognostic power compared to individual EMT markers and were independent prognostic markers. As the previously established scoring method required five markers and stringent criteria, its clinical use might be limited. Therefore, using these novel combined prognostic markers, either FcFsPs or FcSnPs, may be useful in predicting CRC patient outcomes. [ABSTRACT FROM AUTHOR]

Background: Along the southern shoreline of Lake Malawi, the incidence of schistosomiasis is increasing with snails of the genera Bulinus and Biomphalaria transmitting urogenital and intestinal schistosomiasis, respectively. Since the underlying distribution of snails is partially known, often being focal, developing pragmatic spatial models that interpolate snail information across under-sampled regions is required to understand and assess current and future risk of schistosomiasis. Methods: A secondary geospatial analysis of recently collected malacological and environmental survey data was undertaken. Using a Bayesian Poisson latent Gaussian process model, abundance data were fitted for Bulinus and Biomphalaria. Interpolating the abundance of snails along the shoreline (given their relative distance along the shoreline) was achieved by smoothing, using extracted environmental rainfall, land surface temperature (LST), evapotranspiration, normalised difference vegetation index (NDVI) and soil type covariate data for all predicted locations. Our adopted model used a combination of two-dimensional (2D) and one dimensional (1D) mapping. Results: A significant association between normalised difference vegetation index (NDVI) and abundance of Bulinus spp. was detected (log risk ratio − 0.83, 95% CrI − 1.57, − 0.09). A qualitatively similar association was found between NDVI and Biomphalaria sp. but was not statistically significant (log risk ratio − 1.42, 95% CrI − 3.09, 0.10). Analyses of all other environmental data were considered non-significant. Conclusions: The spatial range in which interpolation of snail distributions is possible appears < 10km owing to fine-scale biotic and abiotic heterogeneities. The forthcoming challenge is to refine geospatial sampling frameworks with future opportunities to map schistosomiasis within actual or predicted snail distributions. In so doing, this would better reveal local environmental transmission possibilities. [ABSTRACT FROM AUTHOR]

Background: Gastropods of the genus Biomphalaria (Family Planorbidae) are exploited as vectors by Schistosoma mansoni, the most common causative agent of human intestinal schistosomiasis. Using improved genomic resources, overviews of how Biomphalaria responds to S. mansoni and other metazoan parasites can provide unique insights into the reproductive, immune, and other systems of invertebrate hosts, and their responses to parasite challenges. Results: Using Illumina-based RNA-Seq, we compared the responses of iM line B. glabrata at 2, 8, and 40 days post-infection (dpi) to single infections with S. mansoni, Echinostoma paraensei (both digenetic trematodes) or Daubaylia potomaca (a nematode parasite of planorbid snails). Responses were compared to unexposed time-matched control snails. We observed: (1) each parasite provoked a distinctive response with a predominance of down-regulated snail genes at all time points following exposure to either trematode, and of up-regulated genes at 8 and especially 40dpi following nematode exposure; (2) At 2 and 8dpi with either trematode, several snail genes associated with gametogenesis (particularly spermatogenesis) were down-regulated. Regarding the phenomenon of trematode-mediated parasitic castration in molluscs, we define for the first time a complement of host genes that are targeted, as early as 2dpi when trematode larvae are still small; (3) Differential gene expression of snails with trematode infection at 40dpi, when snails were shedding cercariae, was unexpectedly modest and revealed down-regulation of genes involved in the production of egg mass proteins and peptide processing; and (4) surprisingly, D. potomaca provoked up-regulation at 40dpi of many of the reproduction-related snail genes noted to be down-regulated at 2 and 8dpi following trematode infection. Happening at a time when B. glabrata began to succumb to D. potomaca, we hypothesize this response represents an unexpected form of fecundity compensation. We also document expression patterns for other Biomphalaria gene families, including fibrinogen domain-containing proteins (FReDs), C-type lectins, G-protein coupled receptors, biomphalysins, and protease and protease inhibitors. Conclusions: Our study is relevant in identifying several genes involved in reproduction that are targeted by parasites in the vector snail B. glabrata and that might be amenable to manipulation to minimize their ability to serve as vectors of schistosomes. [ABSTRACT FROM AUTHOR]

Schistosomiasis is a neglected tropical disease caused by Schistosoma parasites. Schistosoma are obligate parasites of freshwater Biomphalaria and Bulinus snails, thus controlling snail populations is critical to reducing transmission risk. As snails are sensitive to environmental conditions, we expect their distribution is significantly impacted by global change. Here, we used machine learning, remote sensing, and 30 years of snail occurrence records to map the historical and current distribution of forward-transmitting Biomphalaria hosts throughout Brazil. We identified key features influencing the distribution of suitable habitat and determined how Biomphalaria habitat has changed with climate and urbanization over the last three decades. Our models show that climate change has driven broad shifts in snail host range, whereas expansion of urban and peri-urban areas has driven localized increases in habitat suitability. Elucidating change in Biomphalaria distribution—while accounting for non-linearities that are difficult to detect from local case studies—can help inform schistosomiasis control strategies. Schistosomiasis is an emerging urban and peri-urban disease in Brazil and freshwater snails are an obligate host of the causative parasite. Here, the authors investigate the ecological suitability for the three freshwater snail hosts in Brazil and identify changes over time driven by climate and urbanisation. [ABSTRACT FROM AUTHOR]

This study assessed the bioaccumulation patterns of five trace metals (Cd, Cr, Co, Cu, and Zn) in two edible snail species, Theba pisana and Otala spp., collected from a dumpsite in Safi City, Morocco. The results indicated that bioaccumulation might be species-specific, as metal concentration profiles varied between the two snail species. Additionally, higher metal levels in the dumpsite snails confirmed their potential as bioindicators of trace metal pollution in terrestrial environments. However, the distribution of trace elements within the edible parts of the snails showed marked unevenness, with the viscera accumulating more metals than the foot. The study also evaluated the potential human health risks associated with consuming these snails. Trace metal levels in the edible parts exceeded most international safety thresholds. The estimated daily intakes (EDIs) of trace metals through snail consumption were below the provisional tolerable daily intakes (PTDIs) for both children and adults, suggesting that daily consumption is generally safe. Nonetheless, the hazard index (HI) indicated that children might face health risks from long-term consumption of contaminated snails (HI > 1), while adults are less likely to experience such complications (HI < 1). The total target carcinogenic risk (TTCR) was below 1E-04 for both children and adults, indicating negligible to acceptable carcinogenic risks for all consumer groups. [ABSTRACT FROM AUTHOR]

Aquatic ecosystems globally have been invaded by molluscs. Tarebia granifera is a highly successful invader, often becoming the dominant aquatic invertebrate species in an invaded ecosystem. Resultingly, it has been suggested that T. granifera may have severe negative impacts on these invaded ecosystems. Limited information is available regarding the population structures and densities of T. granifera, particularly in invaded countries such as South Africa, and information on this could assist in developing management and control strategies for this invasive species. The present study aimed to assess the current distribution, densities, and population structures of T. granifera in invaded habitats on the Limpopo and Phongolo River systems in South Africa. This was accomplished by collecting aquatic molluscs from sites across these systems. Water quality parameters were measured at each site and water samples were collected for chemical nutrient analyses. The density of snails was determined for each site and the population size and structure as well as birth rate was calculated for T. granifera. Tarebia granifera was found to be the dominant molluscan species in habitats where it was present and all size classes from newborn to mature adults were found throughout at some of the highest densities globally. Worryingly, native molluscan species, were often absent or in much lower densities than reported in literature at sites where T. granifera was present, suggesting a negative effect on the native molluscan density and diversity. Contrary to most previous studies, there were no significant correlations between T. granifera and the selected water quality parameters. Higher densities and newborn recruitment of T. granifera were observed in the spring than in autumn, likely in response to shifts in environmental conditions. This study provides crucial insights into the population structure, densities, and impacts of T. granifera in invaded habitats, particularly for relatively newly invaded regions such as southern Africa. [ABSTRACT FROM AUTHOR]

Fasciolosis is a worldwide distribution zoonosis that causes great damage in ruminant breeding and has the aquatic mollusc Pseudosuccinea columella as an intermediate host. Synthetic molluscicides are the most used for control; however, they are harmful to fauna and flora. Therefore, this study aimed to evaluate the effect of essential oils from Thymus vulgaris, Origanum vulgare, and terpene carvacrol, on adult molluscs and eggs of P. columella. Analysis of EO volatile components was carried out on a gas chromatograph equipment coupled with mass spectrometry selective detector. The studied components were diluted in concentrations of 10, 20, 40, 60, 80 and 100 ppm, and it was observed that O. vulgare at concentrations of 60, 80 and 100 ppm, carvacrol at the concentrations of 80 and 100 ppm, and T. vulgaris at a concentration of 80 ppm led to 100% mortality of molluscs. All concentrations the substances tested showed 100% ovicidal activity. [ABSTRACT FROM AUTHOR]

Background: Terrestrial snails, specifically Theba pisana, represent significant agricultural pests in the Mediterranean region, particularly in Egypt. They are gastropods that cause substantial damage to a variety of vegetation, rendering them important agricultural pests that result in economic losses. In response, we have developed unique and non-toxic molluscicides. The study assessed nine novel heterocycles compared with methomyl as a reference compound, to study their molluscicidal effects on T. pisana. These heterocycles include 2-pyrazolines, 2-oxocyclohex-3-ene, and 3-cyano-2-ethoxypyridine. Results: The obtained data revealed that the majority of the produced chemicals were remarkably effective against T. pisana snails, exhibiting different degrees of toxicity seven days post-treatment. Methomyl exhibited the highest toxicity, followed by prop-2-en-1-one and 1-thiocarbamoyl-2-pyrazoline derivatives, with LC50 values of 44.14, 59.54, and 72.00 ppm, respectively. Conclusions: These findings will inform the potential of these synthetic compounds as one of the sources for molluscicide development and their integration into pest management strategies. [ABSTRACT FROM AUTHOR]

Simple Summary: The invasion of the invasive alien species Pomacea canaliculata is of great concern because of its adverse influences on ecosystems, agriculture, and human health in the Asian region. Metaldehyde-containing molluscicides are often used as an effective method of controlling this species. In view of this, the present study conducted experiments to investigate the lethal concentrations of metaldehyde on Pomacea canaliculata at different exposure times. Moreover, the study also elucidated changes in enzyme activity and provided detailed histopathological evidence that shed light on the mode of action and effects of metaldehyde exposure on Pomacea canaliculata. The findings of this study not only deepen our understanding of the effects of metaldehyde on mollusks, but also provide important insights for developing better control strategies. Pomacea canaliculata, as an invasive exotic species in Asia, can adversely affect crop yields, eco-environment, and human health. Application of molluscicides containing metaldehyde is one effective method for controlling P. canaliculata. In order to investigate the effects of metaldehyde on adult snails, we conducted acute toxicological experiments to investigate the changes in enzyme activities and histopathology after 24 h and 48 h of metaldehyde action. The results showed that the median lethal concentrations (LC) of metaldehyde on P. canaliculata were 3.792, 2.195, 1.833, and 1.706 mg/L at exposure times of 24, 48, 72, and 96 h, respectively. Treatment and time significantly affected acetylcholinesterase (AChE), glutathione S-transferase (GST), and total antioxidant capacity (TAC) activity, with sex significantly affecting AChE, GST, and TAC activity and time significantly affecting carboxylesterase (CarE). In addition, the interaction of treatment and time significantly affected the activity of GST, CarE and TAC. In addition, histopathological changes occurred in the digestive glands, gills and gastropods of apple snail exposed to metaldehyde. Histological examination of the digestive glands included atrophy of the digestive cells, widening of the hemolymph gap, and an increase in basophils. In treated snails, the hemolymph gap in the gills was widely dilated, the columnar cells were disorganized or even necrotic, and the columnar muscle cells in the ventral foot were loosely arranged and the muscle fibers reduced. The findings of this study can provide some references for controlling the toxicity mechanism of invasive species. [ABSTRACT FROM AUTHOR]

Biotic homogenization or the increasing similarity of biota has been documented in urban land snail assemblages in Europe and North America. The resulting biotic homogeneity is caused by a loss of native species and the establishment of non-native species. Climate affects land snail distributions, and because Thailand (exclusive of the southern peninsula) has an almost uniform climate, we hypothesized that urban land snail populations would show a high degree of taxonomic homogeneity. We sampled 76 sites (e.g. yards, temple grounds, restaurants and hotels) over a 38-day period during the rainy season in 2022. These sites included three regions: central (five provinces), north (two provinces) and northeast (five provinces). Both live snails and shells were counted, and the 10,470 counted individuals represented 25 taxa. Biotic homogeneity was indicated by three taxa comprising 69.9% of individuals. By far the most abundant species was the native species Sarika siamensis , which was found at all 76 sites and comprised 50.4% of all individuals. The other two abundant species were non-native species—the giant African snail Lissachatina fulica (60 sites) and Allopeas gracile (50 sites)—both widespread synanthropic species. Three other non-native species were also found. Among native species, slugs, including semislugs, were widespread but occurred in low numbers, and Pupina sp. occurred in high abundance (mean = 97 individuals/site) at 13 highly watered locations within its native range. Urban snail assemblages were not entirely homogeneous, as assemblages in the north region differed from those in the central and northeast regions. In conclusion, urban snail assemblages in Thailand showed a high degree of biotic homogeneity, in large part due to a native species, S. siamensis , indicating that native synanthropic species can contribute to biotic homogeneity. [ABSTRACT FROM AUTHOR]

We investigated the evolutionary patterns of two forest-dwelling endemic terrestrial snails (Gittenedouardia spadicea and Maizania wahlbergi) in the Maputaland–Pondoland–Albany biodiversity hotspot in South Africa to examine the degree of phylogeographical congruence between the two species. Phylogenetic relationships and divergence time estimations within each species were inferred using the combined mitochondrial DNA (mtDNA) sequence dataset for the cytochrome c oxidase subunit I (COI) and large subunit ribosomal RNA (16S rRNA). In addition, the rapidly evolving COI datasets were used to infer intraspecific genetic structure and population differentiation within both species. Phylogeographical concordance factor (PCF) analysis was used to statistically estimate the degree of congruence between the two species at localities where both species were sampled. Phylogenetically, G. spadicea exhibited two clades that diverged during the Plio/Pleistocene, while M. wahlbergi formed a single shallow clade that showed Pleistocene divergence. The haplotype networks for the COI locus demonstrated evidence of geographical and genetic isolation within both species. PCF analysis demonstrated partial phylogeographical concordance, suggesting that the two species may have been affected by similar ancient climatic events. Traits other than poor dispersal capabilities and limited gene flow may also influence how a species responds to fluctuating climate change. [ABSTRACT FROM AUTHOR]

A fauna expedition has been conducted in Padang Bindu Karst, South Sumatra in 2021. Among the collected samples, a total of 111 specimens of Opisthostoma platycephalum (Caenogastropoda: Diplommatinidae) were collected from six sampling plots. This discovery is the first record of the land snail species in the southern of Sumatra island, as previous research only recognized its presence in Aceh, North Sumatra, and Peninsular Malaysia. This discovery contributes to the understanding of the biodiversity of South Sumatran land snails and highlights the importance of protecting limestone habitats. [ABSTRACT FROM AUTHOR]

The freshwater snail Latia neritoides occurs in certain streams and lakes of New Zealand's North Island. It defends itself against predators with a unique mechanism - the release of sticky, glowing mucus. Two possible origins of this defence mucus had earlier been suggested: the foot and the pneumostome area. After examining the glandular system of the foot in a previous study, in the present study we examined the general morphology of L. neritoides, focusing on the mantle cavity. With the first complete 3D model of L. neritoides now available, it is possible to evaluate previous morphological studies and to give non-specialists a better understanding of the soft part anatomy of this fascinating gastropod. As a by-product of this, we also compared the capabilities of μ-CT and HREM on a methodological level. We characterized the two most common gland types in the mantel cavity (Lmcg1/Lmcg2) on the basis of their ultrastructure. They are present in large numbers and, therefore, regarded as likely candidates for being the producers of one or more components of the defence mucus. This notion was confirmed by histochemical analyses of Lmcg1 and Lmcg2 and other gland types in L. neritoides. [ABSTRACT FROM AUTHOR]

The land snails cause damage to their host plants, by feeding on leaves, blooms, flowers, fruits, trunks, limbs and barks. Thus, necessary to control these pests. Phasmarhabditis eagyptiaca Azzam 2023 is a new species of snail parasitic nematode, which was recorded and described with investigate its capability to infect some snails and slugs. This investigation aims to prove the parasitization of the P. eagyptiaca nematode on Eobania vermiculata (Müller, 1774) and clear its effect on snails consequently suitability of the nematodes for application to control gastropods, also to differentiate between the two strains of E. vermiculata. Two strains of Eobania snails were infected with the snail parasitic nematodes P. eagyptiaca. The differences between infected and non-infected snails in histological and protein pattern alterations were investigated. Immunoreactivity as fibroblast region and splitting necrosis and degeneration regions were observed in the head foot, ovary, testis, and digestive gland in the two strains of infected E. vermiculata, in addition to changes in protein patterns. All these alterations lead to snail death. The histopathological alterations in E vermiculata snails infected with snail parasitic nematode P eagyptiaca confirm the parasitic relation between them. Although the immune defense from snails against the parasitic nematodes, the nematodes could kill the snails. This indicates the suitability of this nematode for land gastropods biocontrol. [ABSTRACT FROM AUTHOR]

The larvae of some lampyrid beetles are highly specialized predators of snails. They have been observed to climb on the shells of their prey and use this exposed position to bite and inject secretions potentially originating from the midgut. Besides serving the purpose of extra-oral digestion (EOD), injected compounds also seem to have a paralyzing effect. Up to now, the toxins causing this paralyzing activity have not been identified. In the current study, we provide a first compositional analysis of the midgut secretion from lampyrid larvae, with a focus on identifying putative neurotoxins causing the observed paralyzing effect. For this purpose, we utilized a combined proteo-transcriptomic approach to characterize the compounds present in the midgut secretion of larval stages of Lampyris noctiluca. In terms of the absolute numbers of identified compounds, the midgut secretion is dominated by hydrolyzing enzymes comprising peptidases, carboxylesterases, and glycosidases. However, when considering expression levels, a few rather short cysteine-rich peptides exceed all other compounds. Some of these compounds show moderate similarity to putative neurotoxins identified in the venom of other arthropods and could be responsible for paralyzing effects. In addition to these potential toxins, we provide a list of peptides typical of the midgut secretion of L. noctiluca, supplemented by the corresponding precursor sequences. [ABSTRACT FROM AUTHOR]

Aim: The rat lungworm, Angiostrongylus cantonensis, has recently been found in the city of Valencia, parasitizing rats, Rattus norvegicus and Rattus rattus, its natural definitive hosts. This is the first finding of this zoonotic nematode in continental Europe. After informing local and national health authorities, the collection of local terrestrial snails took place with the aim of elucidating their potential role as intermediate hosts of A. cantonensis. Methods and Results: A total of 145 terrestrial snails, belonging to the species Cernuella virgata, Cornu aspersum, Eobania vermiculata, Otala punctata, Pseudotachea splendida, Rumina decollata and Theba pisana, were randomly collected between May and December 2022 in public gardens, parks and orchards in six districts of Valencia, in five of which A. cantonensis had been reported previously in rats. Once collected and identified, the snails were frozen at −20°C. Subsequently, the DNA was isolated and screened by PCR using specific primers targeting the A. cantonensis COI gene. Seven individual snails, belonging to the species C. virgata, C. aspersum and T. pisana, were positive, for an overall prevalence of 4.8%. The PCR product from one of them was sequenced by Sanger sequencing. Conclusions: The three positive terrestrial snail species are among the edible species that are frequently included in various dishes in Spain. C. virgata is reported as a previously unrecorded intermediate host and should be added to the list of more than 200 species of terrestrial snails that have been reported worldwide as intermediate hosts of the rat lungworm. Considering that these terrestrial snails may release infective larvae of A. cantonensis on leafy green vegetables on which they feed and during their handling and preparation for consumption, prophylactic measures to prevent human neuroangiostrongyliasis in Valencia and other regions to which this zoonotic parasite may spread are recommended. [ABSTRACT FROM AUTHOR]

The intricate relationships between parasites and hosts encompass a wide range of levels, from molecular interactions to population dynamics. Parasites influence not only the physiological processes in the host organism, but also the entire ecosystem, affecting mortality of individuals, the number of offspring through parasitic castration, and matter and energy cycles. Understanding the molecular mechanisms that govern host-parasite relationships and their impact on host physiology and environment remains challenging. In this study, we analyzed how infection with Microphallus trematodes affects the metabolome of two Littorina snail species inhabiting different intertidal zone shore levels. We applied non-targeted GC–MS-based metabolomics to analyze biochemical shifts induced by trematode infection in a host organism. We have identified changes in energy, amino acid, sugar, and lipid metabolism. In particular, we observed intensified amino acid catabolism and nitrogenous catabolites (glutamine, urea) production. These changes primarily correlated with infection and interspecies differences of the hosts rather than shore level. The changes detected in the host metabolism indicate that other aspects of life may have been affected, both within the host organism and at a supra-organismal level. Therefore, we explored changes in microbiota composition, deviations in the host molluscs behavior, and acetylcholinesterase activity (ACE, an enzyme involved in neuromuscular transmission) in relation to infection. Infected snails displayed changes in their microbiome composition. Decreased ACE activity in snails was associated with reduced mobility, but whether it is associated with trematode infection remains unclear. The authors suggest a connection between the identified biochemical changes and the deformation of the shell of molluscs, changes in their behavior, and the associated microbiome. The role of parasitic systems formed by microphallid trematodes and Littorina snails in the nitrogen cycle at the ecosystem level is also assumed. [ABSTRACT FROM AUTHOR]

The Iberian Peninsula constitutes a diversity hotspot with a high number of endemisms, where the land snail genus Iberus is likely the best example. Despite this, its species diversity is still debated as it holds several cryptic species. In the present paper, we use molecular evidence (mitochondrial DNA cytochrome oxidase subunit I) to clarify the position of I. ortizi and three new cryptic species that are described herein: I. giennensis, I. axarciensis and I. antikarianus spp. nov. For this, we sampled 281 sampling points to delimitate a comprehensive geographic mapping of these species. Moreover, we carried out a comprehensive morphometric analysis based on 3205 shells. Our findings show that, morphologically, the three described species overlap in the form of their shells, their morphologies being very similar to other close species with nearby distributions (I. ortizi, I. angustatus and I. marmoratus loxanus). Still, all these species are well-defined by genetic distances, but display allopatric distributions, suggesting that they evolved by allopatric speciation as a consequence of biogeographic isolation. Hence, our findings show insights into the evolution of land snails in southeastern Spain, with implications for their conservation, given that our exhaustive sampling shows that the three species described here have very limited distribution ranges, especially I. antikarianus sp. nov. Our study, moreover, implies an integrated approach to the study of the evolution of land snails, including the sampling of the complete geographic area occupied by the genus, genetic analysis to delimit the actual species range, as well as morphometric analyses to understand the phenotypic differentiation and adaptations of the three new species. [ABSTRACT FROM AUTHOR]

This study was designed to estimate the land snail diversity of coastal Karnataka, India, and to compare it with that of the Western Ghats mountain range. Altogether, 23 species of land snails were recorded, of which 18 species were found in coastal Karnataka and 3 species were confined only to Western Ghats. The highest number of land snails were found in national parks, followed by plantations, and the lowest in open areas. Rhachistia praetermissus was confined to the nagabana of Harekala and Rishetia sp. was only seen in home gardens. Among the plantations, land snail diversity was higher in arecanut plantations and lower in rubber plantations. Land snails such as Mariaella dussumieri and Macrochlamys indica were common to most of the visited habitats. Significant correlation between humidity and species richness of land snails indicates that humidity determines the land snail diversity in coastal Karnataka. Reserve forests/National Parks studied encompass more land snail diversity as they provide heterogeneous habitats and suitable ecological niches. Lower diversity of land snails in plantations and open areas compared to the reserve forests can be attributed to lower habitat complexity and anthropogenic disturbances. [ABSTRACT FROM AUTHOR]

Some exogenous compounds found in nature can control the agricultural pests which cause serious damages to the different crops. Specifically, this study established to assess the molluscicidal effects of crude juice of Citruslimon fruit and Citruslimon peel on the developmental stages of Eobania vermiculata (chocolate band snail) and Monacha cartusiana (glassy clover snail). These juices were used individually against the three, six and nine-month-old and adult of both snails in the laboratory and also applied against adult individuals of each snail species in the field for 21 days. Results showed that the juveniles three months old were more susceptible to C. limon fruit and C. limon peel juices than the other ages of both snails. Moreover, C. limon fruit juice was more effective on the two snail species at all ages than the juice of C. limon peel. The crude suspension of C. limon fruit and C. limon peel caused 73.33& 46.66% and 60 & 46.66% mortality of adult snails of E. vermiculata and M. cartusiana respectively after 14 days of the laboratory experiment. While in the field assay, they were recorded 70.39 & 62.30% and 62.08 & 55.79% reduction of both snail adult individuals consecutively after the same period of application (14 days). Therefore, E. vermiculata snails were more affected by the two suspensions than the snails of M. cartusiana under both laboratory and field conditions. C. limon is a promising potential organic substitute to chemical molluscicide with no harmful impacts on humans and the environment. [ABSTRACT FROM AUTHOR]