Terrestrial Snail Research Articles

A multi-domain snail metallothionein increases cadmium resistance and fitness in Caenorhabditis elegans

Metallothioneins (MTs) are a family of mostly low-molecular weight, cysteine-rich proteins capable of specific metal-ion binding that are involved in metal detoxification and homeostasis, as well as in stress response. In contrast to most other animal species which possess two-domain (bidominial) MTs, some gastropod species have evolved Cd2+-selective multidomain MTs (md-MTs) consisting of several concatenated β3 domains and a single C-terminal β1 domain. Each domain contains three-metal ion clusters and binds three metal ions. The terrestrial snail Alinda biplicata possesses, among other MT isoforms, an md-MT with nine β3 domains and a C-terminal β1 domain (termed 10md-MT), capable of binding up to 30 Cd2+ ions per protein molecule. In the present study, the Alinda biplicata 10md-MT gene and a truncated version consisting of one β3 domain and a single C-terminal β1 domain (2d-MT) were introduced into a Caenorhabditis elegans knock-out strain lacking a native MT gene (mtl-1). The two snail MT constructs consistently increased Cd2+ resistance, and partially improved morphological, life history and physiological fitness traits in the nematode model host Caenorhabditis elegans. This highlights how the engineering of transgenic Caenorhabditis elegans strains expressing snail MTs provides an enhancement of the innate metal detoxification mechanism and in doing so provides a platform for enhanced mechanistic toxicology.

An Ecological Study of the Brown Garden snail Cornu aspersum (Müller, 1774) from selected habitats in Jadiriya in Baghdad vicinity.

The present study is considered a pioneer investigation that deal with the terrestrial brown garden snail Cornu aspersum (Müller), in Iraq. Cornu aspersum however is considered an exotic species in many parts of the world ,The species is most probably infiltrates with plants transferred from one place to another. The species has gained importance in many ways. Nutritionally, the species is consumed as food item in many countries, but in other cases it is considered as pest for the damage it causes when feeding on valuable plant shoots. It also has medical importance for its role and ability in healing wounds, burns and remedy of other skin problems. This snail species however may act as a vector for some parasitic nematodes that cause serious diseases. The species is also important in scientific research, usually referred to as ‘ecological indicator’ employed in environmental pollution problems such as the one caused by heavy metals. A great deal of research on this species has been carried out in different parts of the world, however, in Iraq, the scientific attention given to land snails in general and to Cornu aspersum in particular is rare and may be negligible in comparison with the research carried out on aquatic Mollusca species. A total of 1880 individuals of Cornu aspersum were collected from all sampling sites. The study was carried out for the period November 2007 to November 2008 on three sites within the Jadiriya district in Baghdad.. Growth, size classes and shell dimensions of Cornu aspersum populations, and their relationship with major environmental factors; ambient temperature; soil pH, moisture, texture; and the soil content of organic matter have been also investigated. Identification of the species was confirmed by the British Natural History Museum.The data were analyzed by means of standard statistical procedures.

Melanoides tuberculata and Zootecus insularis gastropod shells provide a snapshot into past hydroclimatic conditions of arid environments: New perspectives from Oman

Shells of the aquatic gastropod Melanoides tuberculata and the terrestrial gastropod Zootecus insularis were analysed using high-resolution isotope sampling (up to 274 samples per shell) to assess their potential use as a proxy for hydroclimatic and palaeoenvironmental reconstruction in drylands. A total of 169 snails (fossil and modern) were collected from 37 sites in Northern Oman and Dhofar, with each site selected for its specific geomorphological, archaeological or ecological context. This included fluvial terraces, playa environments, modern oasis gardens, irrigation channels and Neolithic (6000–3200 BCE) and Early Bronze Age (3200–2000 BCE) archaeological sites. The δ18O data obtained from these gastropods could be classified into eight different patterns, three for the aquatic snails (Type 1 A–C) and five for the terrestrial snails (Type 2 A–E), which were linked to the environmental context of their habitat. Furthermore, the use of the aquatic snails enabled us to distinguish between groundwater and surface water signals, whereas the terrestrial snails were employed to reconstruct changes in rainfall origin, humidity, evaporation, regular wet-dry cycles, and/or the presence of meteorological events such as cyclones. According to the results, gastropods can be used to elucidate the long-term, local evolution of rain-fed floodplain ecosystems in drylands and to identify the hydrological resources present in the vicinity of archaeological sites, particularly with regard to type (e.g., surface water vs groundwater).

Gastropods on the green roof of a high-rise building in a large European city

Understanding the distribution and diversity of terrestrial snails on green roofs (GR) can facilitate insights into the ecological functioning of these urban habitats. While green roofs have been shown to provide suitable habitat for mobile species such as birds and insects, there needs to be more research concerning the colonisation and persistence of less mobile animal groups, including terrestrial gastropods. The present study investigates the species richness of terrestrial gastropods on green roofs of high-rise buildings in Bratislava, Slovakia. The study examined four distinct types of green roofs: The green roofs were classified according to their management intensity, resulting in four categories: extensive, semi-intensive GR-A, semi-intensive GR-B, and intensive. The categories differed in terms of vegetation, substrate depth, irrigation, and sun exposure. The survey employed a variety of methods, including pitfall trapping, vegetation sweeping, soil sampling, and microhabitat investigations. The survey yielded evidence of 11 species of terrestrial gastropods (six snails and five slugs) inhabiting three GR types. The semi-intensive GR-A, which is characterised by dense vegetation and minimal management, supported all 11 species. No gastropods were observed on the extensive GR with shallow substrate and Sedum sp. vegetation. The presence of native and non-native species, including the non-native slug Ambigolimax valentianus, indicates that terrestrial gastropods can colonise GR. These findings emphasise the potential of GR to support urban biodiversity and highlight the need for further research on less mobile species in these habitats.

Antibiotic Resistance Hotspot: Comparative Genomics Reveals Multiple Strains of Multidrug-Resistant Citrobacter portucalensis in Edible Snails.

The demand for terrestrial snails as a food source is still on the increase globally, yet this has been overlooked in disease epidemiology and the spread of antimicrobial resistance. This study conducted genomic analyses of twenty Citrobacter portucalensis strains isolated from live edible snails traded in two hubs. The isolates were subjected to MALDI-TOF MS, antimicrobial resistance testing, whole genome sequencing, and analyses for in-depth characterization. The findings disclosed that seventeen strains across the two trading hubs were distinct from previously reported ones. Four isolates were found to share the same sequence type (ST881). Genome-based comparison suggests a clonal transmission of strains between snails traded in these hubs. All the isolates across the two hubs harbored similar variety of antimicrobial resistance genes, with notable ones being blaCMY and qnrB. Sixteen isolates (80%) expressed phenotypic resistance to second-generation cephalosporins, while eleven isolates (55%) exhibited resistance to third-generation cephalosporins. This report of multi-drug-resistant C. portucalensis strains in edible snails highlights significant concerns for food safety and clinical health because of the potential transmission to humans. Enhanced surveillance and stringent monitoring by health authorities are essential to evaluate the impact of these strains on the burden of antimicrobial resistance and to address the associated risk.

Preliminary Data on the Species Composition and Distribution of Land Snail (Mollusca: Gastropoda) in Son Doong Cave, Phongnha - Kebang National Park

Son Doong Cave it is the largest cave on the planet and also the most majestic cave in Vietnam. Son Doong Cave is divided into habitats: Dark cave (covered by the cave ceiling) and light cave (not covered by the cave ceiling), including doline 1 and doline 2.Surveying and collecting land snail samples in Son Doong cave was carried out in January 2023. For the first time, the list of terrestrial snail species in Son Doong Cave was published. This includes 30 species (11 phenotyps are just only identified to genus) belonging to 24 genera, 11 families, 3 orders, 3 subclasses; of which the presence of 5 species (Pincerna mouhoti, Leptopoma perlucidum, Scabrina patera, Chloritis khammouanensis, Amphidromus haematostoma) are newly recorded and added to the list of terrestrial gastropod fauna of Vietnam. In Son Doong cave, land snails are only distributed in the light part of the cave (Doline 1 and Doline 2), not in the dark part of the cave, which accounts for most of the cave area. Doline 2 has a higher species diversity (27 species belonging to 22 genera, 8 families, 2 orders) than Doline 1 (13 species belonging to 11 genera, 6 families, 3 orders). The diversity of land snail species in Son Doong cave is very unique and highly distinctive, but the species populations here is very small, requiring recommendations for tourists and the management board to protect vegetation to maintain and develop populations of this species.

SEASONAL SPECIES COMPOSITION AND RICHNESS OF TERRESTRIAL MOLLUSKS IN PROTECTED AREA (CROSS RIVER NATIONAL PARK) CROSS RIVER STATE

Terrestrial snails are key indicators of climatic changes and ecosystem health. This study recorded 2456 land molluscs from 22 species in 6 families across 20 plots. The most abundant families were Urocyclidae, Streptaxidae, and Archatinidae, comprising 90.82% of the total collection. Aillyidae, Cyclophoridae, and Succineidae had the fewest species. Gymnarion sp. (Subulinidae) was the most numerous with 997 individuals, followed by Gonaxis camerunensis. Margalef’s index indicated the highest species richness in the Buffer Zone (3.18). Shannon-Weiner’s index revealed the highest diversity (2.26) in the Buffer Zone. Chao 2 and Jackknife estimators for Nkunaya were 22.13 and 21.13, respectively, while for the Buffer Zone they were 21.90 and 24.24. The Whittaker Index for the Buffer Zone was 1.47, showing low differentiation among plots.

The potentials and limitations of two taxa of terrestrial snails (polygyra spp. And euglandina rosea) as a source material for the radiocarbon dating of indigenous shell mounds and middens in florida, usa

Preferred materials for radiocarbon dating are often rare on coastal archaeological sites, leading many archaeologists to date more common and abundant marine shells. But marine shell is often difficult to reliably radiocarbon date owing to the effects of the marine reservoir effect, especially where local environmental factors such as hardwater and limestone substrates complicate corrections. Terrestrial gastropods provide a potential alternative material for radiocarbon dating, although they are variably impacted by the same environmental factors and thus require testing to determine their reliability for dating archaeological deposits. We compare radiocarbon dating results from paired archaeological samples of wood charcoal and Odocoileus virginianus (white-tailed deer) bone with the shells of two terrestrial snail taxa—Polygyra spp. (flat coil snails) and Euglandina rosea (rosy wolf snails)—from the Cockroach Key archaeological site, in Tampa Bay, an open-water estuary on the western coast of the Florida Peninsula, USA. In one-third of the total 12 pairings, we found no statistically significant difference at the 95% probability level. For the other pairings, differences between snail shell dates and the reference dates ranged from decades to several centuries. Overall, our results suggest that both taxa have the potential to yield reliable radiocarbon dates, although not without complications.

The effects of polystyrene microparticles on the environmental availability and bioavailability of As, Cd and Hg in soil for the land snail Cantareus aspersus

The combined contamination of terrestrial environments by metal(loid)s (MEs) and microplastics (MPs) is a major environmental issue. Once MPs enter soils, they can interact with MEs and modify their environmental availability, environmental bioavailability, and potential toxic effects on biota. Although research efforts have been made to describe the underlying mechanisms driving MP and ME interactions, the effects of MPs on ME bioavailability in terrestrial Mollusca have not yet been documented. To fill this gap, we exposed the terrestrial snail Cantareus aspersus to different combinations of polystyrene (PS) and arsenic (As), cadmium (Cd), or mercury (Hg) concentrations. Using kinetic approaches, we then assessed the variations in the environmental availability of As, Cd or Hg after three weeks of equilibration and in the environmental bioavailability of As, Cd or Hg to snails after four weeks of exposure. We showed that while environmental availability was influenced by the total ME concentration, the effects of PS were limited. Although an increase in As availability was observed for the highest exposure concentrations at the beginning of the experiment, the soil ageing processes led to rapid adsorption in the soil regardless of the PS particle concentration. Concerning transfers to snail, ME bioaccumulation was ME concentration-dependent but not modified by the PS concentration in the soils. Nevertheless, the kinetic approaches evidenced an increase in As (2- to 2.6-fold) and Cd (1.6-fold), but not Hg, environmental bioavailability or excretion (2.3- to 3.6-fold for As, 1.8-fold for Cd) at low PS concentrations. However, these impacts were no longer observable at the highest PS exposure concentrations because of the increase in the bioaccessibility of MEs in the snail digestive tract. The generalization of such hormetic responses and the identification of the precise mechanisms involved necessitate further research to deepen our understanding of the MP-mediated behaviour of MEs in co-occurring scenarios.

Potential role of gastro-intestinal microbiota in terrestrial snails

This review provides an overview of the potential impact of the intestinal microbiota of land snails on their survival and functioning in a constantly changing environment. The diverse communities of microorganisms that inhabit both the outside and inside of animals in unique ecosystems help them to survive in constantly changing environmental conditions. A diverse microbial community is critical for digestion and nutrient delivery, but it is also important for animals that are adapting to new ecological niches. Molluscs are stable, multicellular in vivo systems that can be used to study the symbiotic relationships between microorganisms and animals, as well as how microbes affect an animal???s physiology and ecology. Furthermore, because of the vast number of species and the ecological diversity of molluscs, they allow for a better understanding of the variability of the microbiota associated with both their location in the host organism and the host in the environment. The microbiome is critical to a body’s homeostasis and survival in changing environmental conditions. This is true not only for terrestrial molluscs, but also for freshwater and marine species, which use the properties of the microorganisms that inhabit them to counteract the effects of stress.

Bio-fertilization of arid lands by terrestrial snails-targeting the wider physiological, geomorphological and agricultural perspectives

Surveys in arid regions worldwide reveal the widespread presence of naturally found Terrestrial Snails (TSs) in extreme arid and semi-arid regions and poor soil conditions such as eroded loess plains. A significant beneficial connection between TS and their impact on ecosystem functioning is suggested including their use as bio-fertilizers. The study was conducted from 2017 to 2023 in Northern Negev, Israel, at the PWA farm and Sayeret-Shaked LTER. The study aimed to determine the influence of TSs on soil fertility and explore its potential contribution to sustainable and profitable agriculture. The findings indicate that the local TSs contributed to a 2% increase in organic matter content, a significant 60% increase in Calcite-Magnetite, and up to six times higher levels of soluble Calcium and Magnesium compared to unaffected soil. An increase with a potential for CO2 inorganic sequestration. It is also indicated that successful agricultural utilization of TS relies on unmanaged rocky slopes for reproduction, designated migration paths for farmland access, and a unique cultivation approach to enhance decomposition. The finding may enable policymakers, and regional or government agencies to further invest in local ecosystems, and effective management tools for enhancing the reproduction of bio-fertilizers such as TS are also raised.

Bioaccumulation of trace metals in edible terrestrial snails, Theba pisana and Otala spp., in a dumpsite area in Morocco and assessment of human health risks for consumers.

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.

High heteroplasmy is associated with low mitochondrial copy number and selection against non-synonymous mutations in the snail Cepaea nemoralis

Molluscan mitochondrial genomes are unusual because they show wide variation in size, radical genome rearrangements and frequently show high variation (> 10%) within species. As progress in understanding this variation has been limited, we used whole genome sequencing of a six-generation matriline of the terrestrial snail Cepaea nemoralis, as well as whole genome sequences from wild-collected C. nemoralis, the sister species C. hortensis, and multiple other snail species to explore the origins of mitochondrial DNA (mtDNA) variation. The main finding is that a high rate of SNP heteroplasmy in somatic tissue was negatively correlated with mtDNA copy number in both Cepaea species. In individuals with under ten mtDNA copies per nuclear genome, more than 10% of all positions were heteroplasmic, with evidence for transmission of this heteroplasmy through the germline. Further analyses showed evidence for purifying selection acting on non-synonymous mutations, even at low frequency of the rare allele, especially in cytochrome oxidase subunit 1 and cytochrome b. The mtDNA of some individuals of Cepaea nemoralis contained a length heteroplasmy, including up to 12 direct repeat copies of tRNA-Val, with 24 copies in another snail, Candidula rugosiuscula, and repeats of tRNA-Thr in C. hortensis. These repeats likely arise due to error prone replication but are not correlated with mitochondrial copy number in C. nemoralis. Overall, the findings provide key insights into mechanisms of replication, mutation and evolution in molluscan mtDNA, and so will inform wider studies on the biology and evolution of mtDNA across animal phyla.

A small collection of terrestrial snails (Mollusca: Gastropoda) from Unguja Island (Zanzibar, Tanzania) revealed a species unknown for 67 years

The study presents findings from a survey of terrestrial snails conducted on Unguja Island (Zanzibar). The survey, conducted in March 2024, focused on the eastern coast of the island, specifically around Uroa Village and Kiwengwa Cave. A total of 12 species of terrestrial snails were recorded, including Gulella minutissima (Thiele, 1911), previously unknown for over six decades.

Influence of cellulolytic preparation on the productive qualities of snails of the Helix Aspersa Maxima species

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. Key words: snails, industry, enzyme preparation, productivity, feeding, technology, cultivation.

Immunotherapeutic Potential of Mollusk Hemocyanins in Murine Model of Melanoma.

We established a murine model of melanoma by challenging C57BL/6 mice with a B16F10 cell line for solid tumor formation in experimental animals. The anticancer properties of hemocyanins isolated from the marine snail Rapana thomasiana (RtH) and the terrestrial snail Helix aspersa (HaH) were evaluated in this melanoma model using various schemes of therapy. Flow cytometry, ELISA, proliferation, and cytotoxicity assays, as well as histology investigations, were also performed. Beneficial effects on tumor growth, tumor incidence, and survival of tumor-bearing C57BL/6 mice after administration of the RtH or HaH were observed. The generation of high titers of melanoma-specific IgM antibodies, pro-inflammatory cytokines, and tumor-specific CTLs, and high levels of tumor-infiltrated M1 macrophages enhanced the immune reaction and tumor suppression. Both RtH and HaH exhibited promising properties for applications as antitumor therapeutic agents and future experiments with humans.

Biocontrol potential of some bacterial and fungal isolates against the terrestrial snail, Monacha obstructa, evaluating their laboratory and field efficiency

BackgroundThe land snail Monacha obstructa, commonly known as the glassy clover snail, poses a significant threat to crops, causing substantial damage in agriculture and horticulture. It particularly thrives in regions of Egypt, where it can reproduce rapidly, leading to substantial population increases and consequent damage. This study aimed to perform laboratory experiments and field trials to assess the effectiveness of bacterial (Bacillus thuringiensis) and fungal (Metarhizium anisopliae and Trichoderma harzianum) isolates, as well as methomyl, a carbamate compound approved by the Ministry of Agriculture in Egypt against the terrestrial snails. Various methods including contact and leaf dipping as well as baiting techniques were applied under both laboratory and field conditions, using spray and baiting techniques.ResultsBacillus thuringiensis (Bt) and M. anisopliae isolates showed the most effective results outcomes in comparison with methomyl against M. obstructa. Out of all the application approaches tested, the residual film (contact) technique of these microorganisms proved to be the most potent, with LC50 values of 6.49 × 106 cells/ml Bt (after 14 days), 1.24 × 108 and 1.49 × 108 spores/ml (M. anisopliae, T. harzianum, respectively), after 21 days and 620 ppm, for methomyl after 7 days of treatments. Besides, the findings demonstrated that Bt exhibited the highest success rate in decreasing the number of snails in the field. It was also observed that pathological symptoms increased as the duration of exposure increased, and the snails ceased to feed and showed a noticeable decline in their activity. A slimy, almost tan-like substance coated the exterior of their shells for Bt, and part of the soft body came out of the shell for M. anisopliae. In the case of T. harzianum, fungus hypha growth took on a white color formed inside the shell, and in addition, a black substance formed on the mouth of the shell.ConclusionsThe gathered data revealed that Bt and M. anisopliae effectively combatted the terrestrial snail, making them viable options in integrated pest control as substitutes for pesticides.

Molluskicidal activity of synthetic organic compounds (on the foot of Achatina fulica (Bowdich)

Terrestrial snails are economically destructive agricultural pests that cause great damage to vegetables and crops. The present study was performed to evaluate the toxicity of synthetic organic derivatives and subsequent histopathological alterations in the feet of Achatina fulica (Bowdich) after exposure to (E)-1-(4-bromophenyl)-3-(4-methylthiazole-5-yl) prop-2-en-1. Accordingly, the LC50 of the synthetic organic derivative was determined to be 1.4206±0.0981. These chemicals can easily penetrate the body of mollusks either by feeding or crawling on the surface, and the foot is the first point of contact. Histopathological and ultrastructural alterations were observed in the foot of Achatina fulica (Bowdich), as these organs play important roles in locomotion and mucus secretion. These alterations include degeneration of the normal structure of the cell by rupturing of the outer protecting membrane, and a large gap is created between the cells. The longitudinal muscle band is destroyed by increasing the space. These results are important from an economic point of view since these synthetic chemical compounds were used as molluskicdes for the control of Achatina fulica (Bowdich), which is an agricultural pest.

Potential molluscicidal activity of the aqueous extracts of some plants and their powders against terrestrial snail Monacha obstructa (L. Pfeiffer, 1842) under laboratory and field conditions

As it is known that the excessive use of pesticides causes many environmental problems, the effects of four aqueous plant extracts and their powders [Solanum nigrum L., Withania somnifera (L.) Dunal, Salix mucronata Thunb. and Lawsonia inermis L.] were evaluated as natural molluscicides on the land snail Monacha obstructa (Family: Hygromiidae) under laboratory conditions. Three different bioassay methods were used: contact, leaf-dipping and bait techniques. The results indicated that, using all methods, S. Nigrum extract was the most toxic extract for the terrestrial snail M. obstructa. The contact technique of the tested plant extracts was the most effective method of application compared to other methods. Moreover, using plant extracts was better than using powders of these plants for controlling the terrestrial snail M. obstructa. In addition, the results indicated that the aqueous extract of S. nigrum gave the highest percentage of reduction in the snail population when assessed under field conditions. The obtained data showed that plant extracts were significantly effective against the terrestrial snail and could be used as alternatives to pesticides in integrated pest management.

Local terrestrial snails as natural intermediate hosts of the zoonotic parasite Angiostrongylus cantonensis in the new European endemic area of Valencia, Spain.

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. 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. 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.