Does commercial indoxacarb pose ecotoxicological consequences? Employing a multi-marker approach in the model species Theba pisana.

Indoxacarb is one of the most extensively used oxadiazine insecticides worldwide, but it may exert detrimental effects on ecosystems, population dynamics, and health. Due to the lack of knowledge on the ecotoxicity of indoxacarb, it is still challenging to assess whether this insecticide poses an ecotoxicological impact on terrestrial environments. Therefore, our study aims to provide novel data on the toxic effects of 28-day dietary exposure to commercial grade indoxacarb at two environmentally relevant concentrations, 0.02 µg/mL and tenfold (0.2 µg/mL) on the model species, Theba pisana. Their effects were studied using a multiple biomarker approach by evaluating physiological, biochemical, and histopathological responses. After 28 days of treatment, indoxacarb at both concentrations significantly reduced the food intake and growth of the treated snails. Also, it caused decreases in lipid peroxidation (LPO)  levels after 7 and 14 days of exposure, whereas an opposite effect occurred after 21 and 28 days. All treated snails were found to exhibit a lower content of glutathione (GSH) after all times of exposure. Moreover, catalase (CAT), glutathione-S-transferase (GST), and glutathione peroxidase (GPx) activities, as well as protein content (PC), were elevated in the treated snails after all time intervals. Post exposure to both realistic indoxacarb concentrations, changes in acetylcholinesterase (AChE) activity between a decrease and an increase were observed. Furthermore, indoxacarb caused histo-architectural changes in the hepatopancreas of T. pisana. Our results demonstrate that, at environmentally relevant concentrations, indoxacarb poses negative consequences for T. pisana, indicating its ecotoxicological impacts.

Survival of Escherichia coli in Edible Land Snails: Implications for Heliciculture and Public Health.

BACKGROUND: Land snails are considered a delicacy in many countries in Europe and sub-Saharan Africa. However, the interaction of microbial pathogens with land snails may present a public health threat when handling and/or consuming snails. This study examines the survival of Escherichia coli in edible land snails in a model system. METHODS: Well-studied Shigatoxigenic (STEC) and non-STEC strains were compared. Mature Helix spp. were experimentally fed with E. coli-inoculated oats for 48 h. The snail feces after inoculation were periodically sampled and cultured for a 30-day period and subjected to microbiological analyses. RESULTS: The average rate of decline of the non-STEC strain CSH-62 in the feces of live snails was significantly (p < 0.05) faster than that of STEC ERL 06-2503. In addition, the viable population of E. coli ERL 06-2503 significantly (p < 0.05) persisted for a longer time in the intestine of land snails than E. coli CSH-62. CONCLUSION: The results showed that the viable population of the E. coli strains examined demonstrated first-order kinetics, and their survival (CFU/mL) appeared significantly (p < 0.05) dependent on the E. coli pathotype. In addition, the continuous enumeration of E. coli in snail faeces indicated that land snails could serve as a mode of transmission of microbial pathogens to susceptible hosts, including humans. Further research is recommended to better quantify the direct and indirect health risks of pathogen transmission by edible snails to humans.

Evidence for Beneficial Physiological Responses of the Land Snail Cornu aspersum to Probiotics' (Lactobacillus plantarum) Dietary Intervention.

A large variety of microorganisms ingested with food constitute animals' intestinal microflora, enhancing and maintaining the homeostasis of the host. Rations enriched with probiotics are a method recommended to prevent undesirable conditions. To date, research has been limited to farmed animals and reared fish, creating a knowledge gap concerning the effect of probiotics on the growth rate, physiological responses, and energy metabolism of invertebrates such as the land snail Cornu aspersum. Herein, juvenile snails (26.23 ± 0.5 mm shell diameter and 8.23 ± 1.02 g body weight) were fed L. plantarum probiotic-enriched rations in two different proportions (1.25 mg and 2.5 mg), and their growth rate was monitored for three months. Additionally, the RNA/DNA and Bax/Bcl-2 ratios, HSP gene expression and protein levels, and ND2 expression, were measured in the hepatopancreas, digestive tract, and mantle. Although the snails' growth rate was not affected, the RNA/DNA ratio presented an increase in various tissues, indicating an intense physiological response. Also, probiotic administration demonstrated low levels of the Bax/Bcl-2 ratio. HSP levels were higher in the presence of probiotics, probably signaling an attempt by the animal to face potentially stressful situations. Finally, ND2 expression levels in the hepatopancreas indicate intense metabolic and antioxidant activity.

The land snail fauna of Batu Kudik, isolated limestone outcrop near Simunjan, Sarawak, Malaysian Borneo (Mollusca, Gastropoda).

Background: The present study provides a checklist of land snails collected from Batu Kudik, a small and isolated limestone outcrop in Simunjan, Sarawak. A total of 24 species of land snails, representing 18 genera and 14 families were recorded, including one newly-described subspecies. The most species-rich of the families in Batu Kudik are Diplommatinidae (17%) and Chronidae (17%) with four recorded species from each of the families. Based on our analysis, Plectostomawallaceikudikense subsp. nov., Opisthostomajavanica and Georissapyrrhoderma were identified as the most abundant land snails at this isolated outcrop, whereas Diplommatinaonyx and Everettiaminuta were recorded as the least abundant. All of the land snails at Batu Kudik were exclusively found sheltered between limestone boulders, underscoring the critical role of this outcrop as their refuge for survival. Consequently, conserving this biodiversity-rich limestone area becomes paramount to prevent the local extinction of these land snail species and possibly other organisms that depend on the unique attributes of the limestone for their survival. We also provide detailed descriptions of Plectostomawallaceikudikense, a new subspecies of the genus Plectostoma which is endemic to Batu Kudik. New information: A description of a new subspecies Plectostomawallaceikudikense subsp. nov.

Molluscicidal activity of calcium borate nanoparticles with kodom ball-flower structure on hematological, histological and biochemical parameters of Eobania vermiculata snails.

Land snails are the most harmful pests in agricultural fields. Eobania vermiculata is a widespread snail species that causes massive damage to all agricultural crops. Thus, the molluscicidal activity of calcium borate nanoparticles (CB-NPs) against Eobania vermiculata was evaluated and compared with metaldehyde (Gastrotox® E 5% G). The amorphous phase of CB-NPs was obtained after thermal treatment at a low temperature (500 °C) which conformed by X-ray diffraction (XRD) analysis. CB-NPs are composed of aggregated nano-sheets with an average thickness of 54 nm which enhanced their molluscicidal activity. These nano-sheets displayed meso-porous network architecture with pore diameters of 13.65 nm, and a 9.46 m2/g specific surface area. CB-NPs and metaldehyde (Gastrotox® E 5% G) exhibited molluscicidal effects on Eobania vermiculata snails with median lethal concentrations LC50 of 175.3 and 60.5 mg/l, respectively, after 72 h of exposure. The results also showed significant reductions of Eobania vermiculata snails hemocytes' mean total number, the levels of Testosterone (T) and Estrogen (E), alkaline phosphatase, acid phosphatase, albumin, and protein concentrations, succinate dehydrogenase, glucose, triglycerides and phospholipids levels, while significant increases in the phagocytic index and mortality index, both transaminases (ALT and AST) and glycogen phosphorylase concentration were observed after the exposure to LC50 of CB-NPs or metaldehyde (Gastrotox® E 5% G) compared to the control group. Therefore, CB-NPs could be used as an alternative molluscicide for controlling Eobania vermiculata, but further studies are needed to assess their effects on non-target organisms.

Redescription and geographical distribution of Leiostracusobliquus (Reeve, 1849) (Mollusca, Gastropoda, Simpulopsidae).

Leiostracus Albers, 1850 was established to allocate land snails from Central America and Northern South America. Currently, approximately 19 species are considered valid. However, for most of them, the internal morphology is unknown. Leiostracusobliquus was described as a species of Bulimus from the state of Bahia based on shell characters. Until now, knowledge of this species has been scarce. The discovery of ethanol-preserved specimens from MZSP of this species allowed us to characterize, for the first time, the internal anatomy of this species and update its distribution. The shell of L.obliquus has seven to eight whorls and a wide pale-pink disrupted band all over the teleoconch. The rachidian tooth is small rectangular, symmetric, with round edges, and without differentiated cusps. After comparing the anatomy and radular characters between the shells of L.obliquus and L.carnavalescus, we found remarkable similarities in the morphology and color pattern.

Speciation of rock-dwelling snail species: Disjunct ranges and mosaic patterns reveal the importance of long-distance dispersal in Chilostoma (Cingulifera) in the European Southern Alps.

To better understand the origin of the high diversity and endemism in the Southern Alps of Europe, we investigated the phylogeny and population structure of the rock-dwelling snail group Chilostoma (Cingulifera) in the Southern Alps. We generated genomic ddRAD data and mitochondrial sequences of 104 Cingulifera specimens from 28 populations and 14 other Ariantinae. Until recently, about 30 Cingulifera taxa were classified as subspecies of a single polytypic species. The phylogenetic and population genetic analyses of the ddRAD data and mitochondrial sequences revealed that Cingulifera in the Southern Alps is differentiated into three species. Each of the three Chilostoma (Cingulifera) species occupies disjunct sub-areas, which are separated by areas occupied by other Chilostoma taxa. Neighbouring populations of different species show little or no admixture. Tests indicating that the genetic differentiation of the three Cingulifera taxa cannot be explained by isolation by distance confirmed their species status. The disjunct range patterns demonstrate the importance of stochastic events such as passive long-distance dispersal for the evolution of population structure and speciation in these snails, and of priority effects and ecological competition as important factors influencing species distributions.

Bio-molluscicidal potential and biochemical mechanisms of clove oil and its main component eugenol against the land snail, Theba pisana.

The land snail, Theba pisana is a serious pest that adversely affects various crops in sustainable agriculture. Essential oils and their constituents represent an environmentally sound alternative to synthetic pesticides. Our study aimed to investigate the lethal and sub-lethal toxicity of clove oil and its main component eugenol to understand the mechanisms underlying its toxic action against T. pisana. The GC-MS profile of the clove oil composition was characterized. In the laboratory experiment, LD50 of clove oil and eugenol via the contact testing were determined after 48 and 72 h. Moreover, sub-lethal effects of clove oil or eugenol on the survivors following the exposure of snails to the 25 and 50% of the LD50/48 and 72 h were evaluated through using snail tissues for biochemical measurments. The GC-MS analysis showed that eugenol (64.87%) was the major constituent present in the oil. The results also showed that LD50 values at 48 and 72 h were 2006.5 and 1493.5 µg/g b.w for oil and 239.6 and 195.3 µg/g b.w for eugenol, respectively. Compared to control, the sub-lethal effects of clove oil or eugenol at 48 and 72 h showed a significant increase in reduced glutathione (GSH) levels. Catalase (CAT) and glutathione-S-transferase (GST) activities significantly elevated in oil- or eugenol-treated snails, except at low dose after 48 h. After two exposure times, snails exposed to oil or eugenol at both sub-lethal effects had considerably higher γ-glutamyltransferase (γ-GT) and aspartate aminotransferase (AST) activities. Moreover, markedly augmentation in alkaline phosphatase (ALP) and alanine aminotransferase (ALT) activities at all exposure times, with the exception of snails treated with low dose of eugenol after 48 h was observed. Both clove oil and eugenol at the tested doses caused a significant inhibition in acetylcholinesterase (AChE) activity at two exposure times. Our findings highlight the potential of clove oil and eugenol, as an efficient natural molluscicide alternative to its synthetic counterparts for snail control.

Cadmium nitrate and DNA methylation in gastropods: comparison between ovotestis and hepatopancreas.

Dietary ingestion is the main route of exposure to hazardous contaminants in land animals. Cadmium, a high-profile toxic metal, affects living systems at different organismal levels, including major storage organs (liver, kidneys), key organs for species survival (gonads), and epigenetic networks regulating gene expression. 5-methylcytosine (5mC) is the most common and best-characterized epigenetic mark among different modified nucleosides in DNA. This important player in methylation-driven gene expression is impacted by cadmium in sentinel terrestrial vertebrates. However, limited information exists regarding its impact on macroinvertebrates, especially land snails commonly used as (eco)toxicological models. We first investigate the methylomic effects of dietary cadmium given as cadmium nitrate on terrestrial mollusks. Mature specimens of the common brown garden snail, Cornu aspersum, were continuously exposed for four weeks to environmentally-relevant cadmium levels. We determined global genomic DNA methylation in hepatopancreas and ovotestis, as well as changes in the methylation status of CG pairs at the 5' region close to the transcription site of gene encoding the Cd-selective metallothionein (Cd-MT). Weight gain/loss, hypometabolism tendency, and survival rates were also assessed. Although this exposure event did not adversely affect survival, gastropods exposed to the highest Cd dose revealed a significant reduction in body weight and a significant increase in hypometabolic behavior. The hepatopancreas, but not the ovotestis, displayed significant hypermethylation, but only for the aforementioned specimens. We also found that the 5' end of the Cd-MT gene was unmethylated in both organs and its methylation status was insensitive to cadmium exposure. Our results are important since they provide scientists, for the first time, with quantitative data on DNA methylation in gastropod ovotestis and refine our understanding of Cd epigenetic effects on terrestrial mollusks.

Long-interval effects of wildfires on the functional diversity of land snails.

In fire-prone regions, fire is a major natural disturbance which shapes ecosystem function and community composition. Fire has a direct and dramatic effect on soil fauna and, especially, on non-mobile species such as land snails. The factors that make the Mediterranean Basin a fire-prone region may also lead to the appearance after fires of certain functional traits related to ecological and physiological characteristics. Knowledge of how community structure and function change along the post-fire succession will be useful for understanding the processes that drive biodiversity patterns in burnt areas and for implementing appropriate biodiversity management strategies. Here, we examine long-interval taxonomic and functional changes occurred in a snail community four and 18 years after a fire in the Sant Llorenç del Munt i l'Obac Natural Park (NE Spain). Our field-based study demonstrates that the land snail assemblage responds both taxonomically and functionally to fire and that there was a clear replacement of dominant species from the first to the second sampling period. Variation in community composition between different post-fire ages can be attributed to snail species traits and successional changes in post-fire habitat conditions. At taxonomic level, there was great variation in snail species turnover between both periods, being the development of the understorey vegetation structure the main driver of this variation. The replacement of functional traits between times since fire suggests that xerophilic and mesophilic preferences play an important role after fire and are largely determined by the complexity of post-fire microhabitats. Our analysis indicates that immediately after a fire there is a time-window of opportunity that attracts species specializing in early successional habitats, which thereafter are replaced due to the changing conditions resulting from succession. Consequently, knowing the functional traits of species is important for determining the impacts of disturbances on the taxonomic and functional communities.

Distribution, conservation status and proposed measures for preservation of Radiodiscus microgastropods in Chile.

The genus Radiodiscus includes minute terrestrial snails occurring throughout the American continent. We assessed the conservation status of eight poorly known Chilean Radiodiscus species using the International Union for Conservation of Nature (IUCN) and NatureServe categories and criteria. Under the IUCN guidelines the species were assessed using the Criterion B of geographic range, which considers the extent of occurrence (EOO) and area of occupancy (AOO) as subcriteria. For NatureServe we used these two parameters plus the number of occurrences, ecological viability, and threats. Considering species rarity and possible sampling bias, we also used ecological niche modeling to determine climate and environmental tolerances and predict potential species distributions analyzing bioclimatic and geographical layers. Radiodiscus australis, R. coarctatus and R. quillajicola were listed as Critically Endangered by IUCN and NatureServe standards; R. coppingeri, R. flammulatus, R. magellanicus and R. villarricensis as Endangered by both methods; while R. riochicoensis as Endangered by IUCN standards and Vulnerable by NatureServe standards. Niche modeling results indicated that Radiodiscus species respond to different environmental conditions and that the predicted distribution areas contain suitable habitats beyond the current ranges, which may be helpful for future management plans. Nature-based sport tourism, forestry activities, urbanization, roads, pollution, mining, forest fires, livestock, volcanism, tsunamis, soil erosion and introduced species are among the major threats affecting these snails. Based on the low number of occurrences and the threats identified, the most at-risk species are R. coarctatus and R. quillajicola (one record), R. australis (two records) and R. villarricensis (three records); the latter two lacking occurrences within protected areas. Compiling our findings, we propose a list of actions to preserve Chilean Radiodiscus species.

Molecular investigation on diversity of the land snail genus Aegista (Gastropoda, Camaenidae) in South Korea.

Aegista Albers, 1850 is a large genus of the land snail family Camaenidae Pilsbry, 1895 and distributed in south, southeast and east Asian countries (from India and Nepal to Korea and Japan). Fourteen species and subspecies of Aegista are known from South Korea. They were described, based only on shell morphology during 1887-1943 and our knowledge on diversity of Korean Aegista has seldom been updated since then. In this study, we provide the report on the first molecular investigation of diversity of Aegista in South Korea, which unmasked some of overlooked diversity of this group.

A new semi-slug of the genus Microparmarion from Brunei, discovered, described and DNA-barcoded on citizen-science 'taxon expeditions' (Gastropoda, Stylommatophora, Ariophantidae).

Background: During citizen-science expeditions to the Ulu Temburong National Park, Brunei, several individuals were collected of a semi-slug species of the genus Microparmarion that, based on morphology and in-the-field DNA-barcoding, was found to be an undescribed species. New information: In this paper, we describe Microparmarionsallehi Wu, Ezzwan & Hamdani, n. sp., after field centre supervisor Md Salleh Abdullah Bat. We provide details on the external and internal reproductive morphology, the shell and the ecology of the type locality, as well as a diagnosis comparing it with related species. DNA barcodes were generated for five individuals and used for a phylogenetic reconstruction. Microparmarionsallehi sp. n. and M.exquadratus Schilthuizen et al., 2019 so far are the only Bornean species of the genus that live in lowland forest; other species are found in montane forests.

Snail meat consumption in Buea-Cameroon: exposures to foodborne pathogens through social practices assessed in 2019 and 2021.

BACKGROUND: Snail meat is an important source of nutrition in Cameroon, but the food safety risks are poorly understood. We characterized public health risks from snail meat consumption as a social system in Cameroon, by examining local snail practices that expose snail meat handlers and consumers to foodborne pathogens. METHODS: We used exploratory qualitative approaches, that is, lived experience, face-to-face in-depth interviews, participant observation and a focus group, to explore fifteen key informants' routines and lived experiences, and perceptions of two health officials on the food safety practices around snail meat consumption in Cameroon. This information was organized and interpreted using Soft Systems Methodology and Social Practice Theory, which permitted a systemic appreciation of local practices. RESULTS: We distinguished five kinds of actors (snail vendors, market sellers, street vendors, street eaters and home consumers), who performed seven successive practices (picking, selling, cracking, washing, cooking, hawking and eating). We then identified three worldviews about snails: family support or to reduce poverty, a source of nutrition and a food choice (taste, preference). Our findings revealed participants' competences were based on childhood learning and 'inborn' experiences, and materials used in snail activities reflected participants' parentage and 'state of poverty'. Although most interviewees highlighted 'unhygienic conditions' when explaining snail picking locations, participants believed washing and cooking should kill all contaminants. CONCLUSION: Several opportunities for human exposures to foodborne pathogens including snail picking in domestic wastes and sewage, the selling of unpackaged live snails, improper snail meat washing and hawking in loosely closed buckets, were apparent from our analysis. These findings suggest fruitful opportunities aimed at improving health outcomes among African snail meat handlers and consumers.

Design, Synthesis, Characterization, and Molluscicidal Activity Screening of New Nicotinonitrile Derivatives against Land Snails, M. cartusiana.

A new series of nicotinonitrile derivatives 2-7 was designed and synthesized from the starting material (E)-3-(4-chlorophenyl)-1-(4-methoxyphenyl)prop-2-en-1-one (1) to assess their molluscicidal activity. The newly synthesized nicotinonitrile compounds 2-7 were characterized based on FTIR, 1H-NMR, and 13C-APT NMR spectra as well as elemental microanalyses. The target compounds 2-7 were screened for their toxicity effect against M. cartusiana land snails and were compared to Acetamiprid as a reference compound. The results demonstrated that the nicotinonitrile-2-thiolate salts 4a and 4b had good mortality compared with that of Acetamiprid. The results of the in vivo effect of the prepared nicotinonitrile molecules 2, 4a, and 4b on biochemical parameters, including AChE, ALT, AST, and TSP, indicated a reduction in the level of AChE and TSP as well as an increase in the concentration of transaminases (ALT and AST). A histopathological study of the digestive gland sections of the M. cartusiana land snails was carried out. The nicotinonitrile-2-thiolate salts 4a,b showed vacuolization, causing the digestive gland to lose its function. It could be concluded that the water-soluble nicotinonitrile-2-thiolate salts 4a,b could be adequate molluscicidal molecules against M. cartusiana land snails.

Public Health Risk of Foodborne Pathogens in Edible African Land Snails, Cameroon.

In tropical countries, land snails are an important food source; however, foodborne disease risks are poorly quantified. We detected Campylobacter spp., Yersinia spp., Listeria spp., Salmonella spp., or Shiga-toxigenic Escherichia coli in 57%-86% of snails in Cameroon. Snail meat is a likely vector for enteric diseases in sub-Saharan Africa countries.

Characterization of polymorphic microsatellite markers for the Japanese endangered land snail Mandarina.

OBJECTIVE: Mandarina is an endangered land snail genus of the oceanic Ogasawara archipelago. On Chichijima Island, the largest inhabited island in Ogasawara, this genus is almost extinct in the wild due to predation by invasive species. Although ex situ conservation programs started in 2010, genetic diversity and population structure remain unclear due to a lack of genetic markers with sufficient genetic variation. In this study, we designed polymorphic microsatellite markers of Mandarina to enable genetic analysis and to develop appropriate conservation plans. RESULTS: Twenty-three polymorphic microsatellite markers were identified from the genomic DNA of wild samples of Mandarina mandarina. We assessed the genetic diversity of each marker. In 16 markers, neither linkage disequilibrium nor deviation from Hardy-Weinberg equilibrium was detected. These 16 markers were tested for multiplex PCR using low-density DNA extracted non-lethally from captive samples of M. mandarina, M. chichijimana and M. suenoae. Of the 16 markers, 15, 12 and 9 were usable for multiplex PCR, respectively. Genetic analysis using these microsatellite loci will be an important resource for the conservation of Mandarina.

Level of oxidative stress for the land snail Cepaea nemoralis from aged and bioremediated soil contaminated with petroleum products.

Here, we investigated whether the widely distributed snail Cepaea nemoralis could be used as a suitable sentinel animal for assessing the effects of soil contaminants-petroleum oil derivatives-after years of soil ageing and treatment with a bacterial formulation. Oxidative stress was assessed in the foot and hepatopancreas of C. nemoralis L. exposed to soil contaminated with unleaded petrol, spent engine oil or diesel oil and bioremediated with a bacterial formulation (soil was used 2 years after contamination and bioremediation process). We measured total antioxidant capacity, catalase and glutathione transferase activity and concentrations of superoxide anions, hydrogen peroxide and protein carbonyls in the foot and hepatopancreas of snails after 2 and 4 weeks of treatment. The studied antioxidant responses appeared largely to be tissue and remediation process specific, while the concentrations of superoxide anions, hydrogen peroxide and protein carbonyls depended on time of exposure, tissue type and the type of contaminants, but mostly not on the remediation process. Generally, changes in the concentrations of superoxide anions, hydrogen peroxide and protein carbonyls in the hepatopancreas of snails seemed to be a suitable measure to assess the risk of animals exposed to soil contaminated with petroleum substances and used after many years of ageing and treatment with a microbial formulation.

Influence of Methomyl (Copter 90%) on certain biochemical activities and histological structures of land snails Monacha cartusiana.

This manuscript was conducted to spotlight the toxic effect of two sub-lethal concentrations of Methomyl (Copter) LC20 (0.075 g/L) and LC40 (0.180 g/L) on some biochemical parameters and histological alterations for land snail Monacha Cartusiana (Muller, 1774). Land snails belong to the class Gastropoda and Phylum Mollusca. This study cleared that both the used concentrations (of Copter) caused a significant increase for activities of three enzymes: alkaline phosphatase (ALP), alanine amino transaminase (ALT), and Aspartate amino transaminase (AST) after 24, 48, and 72 h from exposure starting. In contrast, a total protein (TP) activity decreased at exposure for two concentrations at all lethality periods. Both concentrations of Copter (0.0.75 g/L and 0.180 g/L) have shown histological changes for land snail tissues after 96 h of exposure; digestive gland, hermaphrodite gland, foot, and mantle. Degeneration, rupture, and vacuolization for digestive cells have been shown; furthermore, hemolytic infiltration in connective tissue will be recognized for the digestive gland. The Oocyte and sperm show degenerated with deformation in the connective tissue of the hermaphrodite gland. Likewise, deformation in the muscle fiber layer of the foot in the land snail distorts the epidermis and mucus gland suffering from necrosis. Moreover, mantle shows rapture in epidermis layer, deformed in muscle fiber layer, and vacuolization and necrosis take place in mucus gland.

Insights into the ecotoxicological perturbations induced by the biocide Abamectin in the white snail, Theba pisana.

Abamectin (avermectin B1, ABM) has been widely used as a biocide in agriculture, veterinary and medicine around the world. Yet, there is still a lack of knowledge about the ecotoxicological effects of ABM. In this study, we investigated the acute toxicity and sub-lethal (20% and 60% LD50) biochemical responses of ABM on the non-target land snail, Theba pisana. Mortality of snails increased with the dose increase, resulting 48 h- LD50 value of 1.048 µg/snail. The biochemical results showed a decrease in glycogen content and lipids for two sub-lethal doses after all time intervals, whereas increased the level of total proteins after exposure to 60% LD50 ABM. Overall, the tested sub-lethal doses significantly decreased the total energy reserves. ABM-exposure to snails elevated γ-Glutamyl transferase and Lactate dehydrogenase activities at all-time intervals. A significant increase of Glutathione-S-transferase activity was also recorded in snails exposed to 20% and 60% LD50 after 7 days and all time intervals, respectively. However, ABM inhibited the activity of Aspartate aminotransferase and Alanine aminotransferase after 7 days of exposure. Our investigation provides new insights into the disturbances of energy reserves and enzyme activities in T. pisana that are sensitive and may be used as biomarkers for assessing ABM toxicity.