Cantareus Apertus Research Articles

Diversity and abundance of terrestrial gastropods in Skikda region (North-East Algeria): correlation with soil physicochemical factors

BackgroundThe inventory process is the first method to protect and safeguard animal biodiversity. This study carries out a quantitative and qualitative inventory of terrestrial gastropods at three sites in Skikda province (north-eastern Algeria). The relationship between terrestrial gastropod diversity and soil physicochemical factors was investigated using statistical analyses.ResultsThe inventory data reveals the presence of four families and eight species showing varied predominance rates of Cornu aspersum species according to each site in the city of Skikda (Azzaba 53.88%; Ben-Azzouz 56.12%; El-Hadaiek 37.92%). The maximal specific richness was registered in the El-Hadaiek site (seven species), and the highest mean richness was noted in the Ben-Azzouz site (392 individuals). Of the eight gastropod species identified, three species (Cornu aspersum, Cantareus apertus and Rumina decollate) were classified as constant species. The Shannon–Weaver diversity and equitability indices vary by site.ConclusionThe presence of certain species in one site and their absence in other sites, as well as the variation in ecological indices, could be attributed to the effect of soil-physicochemical factors.

Integrative assessment of the biological responses elicited by metal pollution in the green garden snail, Cantareus apertus: Laboratory and field studies

Abstract Sets of multiple biomarkers can be applied to achieve a comprehensive assessment of the biological impact of the chemical pollutants in contaminated soils. This approach requires the integration of diverse biomarker data into indices that provide early signs of ecosystem health disturbance. Within this context, this study aims at integrating multiple biomarkers in green garden snail, Cantareus apertus, on the basis of data obtained in preceding laboratory and field studies. In the laboratory, snails had been treated with dietary Pb, Cd and their mixture. Prompt (1 wk) and long-lasting (8 wk) response profiles were characterized and the biomarkers integrated as Integrated Biomarker Response (IBR/n) index. The response profiles were dose and treatment time dependent in quantitative terms and also qualitatively different along the treatment time. Yet, IBR/n was sensitive to provide early (1 wk) signs of health disturbance caused by the metals, and remained sensitive in the long term (8 wk). In the field study, soil metal pollution was investigated along a distance gradient from a main roadside. Both metal levels in the soil–plant-snail system and a set of biomarkers in snails were recorded. The IBR/n revealed that disturbance in soil ecosystem health was restricted to short distances (at 20 m but not at 150 m). Therefore, IBR/n was a suitable approach also in the complexity of the field. Moreover, together with the IBR/n index, recently developed indices of bioavailability (SET) and risk (ERITME) were applied in the field study. In accordance with the IBR/n index, the SET index also revealed an excess transfer of metals to snails limited to a short distance from the roadside and identified Cd as the priority target for soil pollution management. Likewise, the ERITME classification rank confirmed that environmental risk was the highest at 20 m away from the roadside and then decreased at 150 m and beyond. Therefore, the application of the IBR/n index together with existing indices of the bioavailability (excess transfer) and risk of contaminants represents a challenging approach for the integrated environmental risk assessment of contaminated soils.

Effects of dietary Pb and Cd and their combination on lysosomal and tissue-level biomarkers and histopathology in digestive gland of the land snail, Cantareus apertus (Born, 1778)

The present study was aimed at determining cell and tissue-level biomarkers and histopathological alterations in the green garden snail, Cantareus apertus (Born, 1778), exposed to different nominal dietary concentrations of Pb (25, 100 and 2500 mg Pb/kg), Cd (5, 10 and 100 mg Cd/kg) and their combination (25 mg Pb + 5 mg Cd/Kg, 100 mg Pb + 10 mg Cd/kg and 2500 mg Pb + 100 mg Cd/ kg) for 1 and 8 weeks. Lead and Cd exerted histopathological effects on the digestive gland in a dose-dependent manner and related to lysosomal and tissue-level biomarkers. The biological responses observed included digestive cell vacuolisation and numerical atrophy, calcium cell hydropic degeneration, excretory cell hypertrophy, inflammatory responses, blood vessel congestion, and disruption of the blood vessel wall and the interstitial connective tissue. Lysosomal enlargement and transient intracellular accumulation of neutral lipids and lipofuscins were also observed, together with alterations in the cell type composition and thinning of the digestive gland epithelium and with diverticular distortion. This response profile fits well with the biological effects reported after metal exposure in gastropods from other regions, as well as with data obtained in parallel studies dealing with metal bioaccumulation and intralysosomal accumulation, mortality, feeding, growth, oxidative stress and neurotoxicity exerted elicited by Pb, Cd and their mixture in green garden snails under the present experimental conditions. Consequently, C. apertus seems to be a suitable model species for the biomarker-based assessment of the biological effects of Pb and Cd, alone or in combinations, thus providing a challenging opportunity to advance in identifying suitable sentinel species for metal pollution biomonitoring and ecosystem health assessment in soil ecosystems in Northern Africa.

Green garden snail, Cantareus apertus, as biomonitor and sentinel for integrative metal pollution assessment in roadside soils.

The present investigation was conceived to study, in a small scale field study, the potential of the green garden snail, Cantareus apertus, as biomonitor and sentinel for integrative metal pollution assessment in soils. For this purpose, we investigated the association between the trace metal (Cd, Pb, As, Fe, Cr, Cu, Ni, and Zn) concentrations in soil, plants (Trifolium repens), and C. apertus depending on the distance (20, 150, and 700m) from a main roadside in Tunisia as well as between metal concentrations and biomarkers of oxidative stress, oxidative damage, and neurotoxicity in C. apertus. Results revealed a clear association between the concentration of metals such as Ni, Cu, and Zn in snail digestive gland, both amongst them and with oxidative stress and neurotoxicity biomarkers recorded in the same organ. Interestingly, Ni, Pb, and Zn occurred at the highest concentration in soil, plant, and snails and the association appeared related to the immediacy of the roadside and the concentration of these three metals tended to decrease with distance from the roadside in the soil-plant-snail system. Conversely, Cd and Cu were bioaccumulated in plants and snails but their concentrations in soil were not high and did not show a decline in concentration with distance from the roadside. After PCA analysis, PC-01 (56% of the variance) represented metal bioaccumulation and associated toxic effects in snails in the presence of high levels of metal pollution (nearby the roadside) while PC-02 (35% of the variance) represented stress induced by moderate levels of metal pollution (at intermediate distances from the roadside). The four studied sites were clearly discriminated one from each other, depending on how they are affected by traffic pollution. In summary, this field study reveals that (a) C. apertus can be used as biomonitor for metal pollution in roadside soils and as sentinel for pollution effects assessment based on biochemical biomarkers; and (b) that oxidative stress and neurotoxicity biomarkers endow with a powerful biological tool for metal pollution biomonitoring in soils, especially in combination with chemical analysis of the soil-plant-snail transfer system. Moreover, this study provides some baseline data for future impact assessments concerning trace metal pollution in Tunisia.

Mercury induced haemocyte alterations in the terrestrial snail Cantareus apertus as novel biomarker

The aim of the present work was to study the response of a suite of cellular and biochemical markers in the terrestrial snail Cantareus apertus exposed to mercury in view of future use as sensitive tool suitable for mercury polluted soil monitoring and assessment. Besides standardized biomarkers (metallothionein, acetylcholinesterase, and lysosomal membrane stability) novel cellular biomarkers on haemolymph cells were analyzed, including changes in the spread cells/round cells ratio and haemocyte morphometric alterations.The animals were exposed for 14days to Lactuca sativa soaked for 1h in HgCl2 solutions (0.5 e 1μM). The temporal dynamics of the responses were assessed by measurements at 3, 7 and 14days.Following exposure to HgCl2 a significant alteration in the relative frequencies of round cells and spread cells was evident, with a time and dose-dependent increase of the frequencies of round cells with respect to spread cells. These changes were accompanied by cellular morphometric alterations.Concomitantly, a high correspondence between these cellular responses and metallothionein tissutal concentration, lysosomal membrane stability and inhibition of AChE was evident.The study highlights the usefulness of the terrestrial snail C. apertus as bioindicator organism for mercury pollution biomonitoring and, in particular, the use of haemocyte alterations as a suitable biomarker of pollutant effect to be included in a multibiomarker strategy.

Bioaccumulation and tissue distribution of Pb and Cd and growth effects in the green garden snail, Cantareus apertus (Born, 1778), after dietary exposure to the metals alone and in combination

The present study was aimed at determining bioaccumulation and cell and tissue distribution of Pb and Cd in the green garden snail, Cantareus apertus (Born, 1778), exposed to different nominal dietary concentrations of Pb (25, 100 and 2500mgPb/kg), Cd (5, 10 and 100mgCd/kg) and their combination (25mg Pb+10mgCd/kg and 2500mg Pb+100mgCd/kg) for 1 and 8wk. Pb and Cd were bioaccumulated in the digestive gland in a dose-dependent manner and the degree of effects on growth was related to the level of exposure, though metal–metal interactions were observed after treatment with mixtures of Pb and Cd. The present results are absolutely comparable to those obtained in other terrestrial pulmonates in other regions and therefore they absolutely support that C. apertus is suitable as biomonitor for the assessment of the Pb and Cd levels and their biological effects in soil ecosystems in Northern Africa.

Effects of Dietary Pb and Cd and Their Combination on Acetyl Cholinesterase Activity in Digestive Gland and Foot of the Green Garden Snail, Cantareus apertus (Born, 1778)

The present study was focused upon the assessment of acetyl-cholinesterase (AChE) activity in the digestive gland (main metabolic center) and foot (highly innervated organ) of the green garden snail, Cantareus apertus (Born, 1778), exposed to different nominal dietary concentrations of Pb (25 and 2500 mg Pb/Kg), Cd (10 and 100 mg Cd/Kg) and their combination (25 mg Pb + 10 mg Cd/Kg and 2500 mg Pb + 100 mg Cd/ Kg) for 60 days. AChE activity was lower in the foot than in the digestive gland (~50%) and decreased with experimental time in both tissues. In metal treated snails, AChE activity was significantly decreased in both tissues to a 50-60% of the values recorded in control snails. This decrease followed a dose depending trend at each exposure time, albeit the response was attenuated at the long-term (60 d) in comparison with the short-term (7 d). Besides, the combination of both metals provoked interactive effects not seemingly related with the tissue levels of the metals. Thus, it was concluded that model toxic metals such as Pd and Cd cause a reduction in AChE activity in both studied tissues, more markedly at the short-term, although antagonistic effects were elicited by both metals in combination. As a whole, lowered AChE activity in C. apertus can be considered as a useful biomarker of the effects provoked by metals on cell signaling and therefore it may be suitable for ecosystem health assessment in metal polluted soils using this species as sentinel organism.

Effects of Dietary Pb and Cd and Their Combination on Glutathion-S-Transferase and Catalase Enzyme Activities in Digestive Gland and Foot of the Green Garden Snail, Cantareus apertus (Born, 1778).

The present study was focused on the assessment of glutathion-S-transferase (GST) and catalase (CAT) activities in the digestive gland and foot of the land snail, Cantareus apertus (Born, 1778), exposed to different nominal dietary concentrations of Pb (25 and 2500mg Pb/Kg), Cd (5 and 100mg Cd/Kg) and their combination (25mg Pb+5mgCd/Kg and 2500mg Pb+100mgCd/Kg) for 7 and 60days. GST activity was significantly increased after 7 and 60days exposure to the highest concentration of Pb, Cd and their combination. The levels of CAT activity were different in the two studied organs but in both cases it resulted increased after 7 and 60days of exposure, which varied significantly between metals and dietary concentrations. Therefore, it can be concluded that GST and CAT enzymes in digestive gland and foot of C. apertus are responsive to Cd, Pb and their combination, whereby they are suitable to be included in a battery of biomarkers for ecosystem health assessment in metal polluted soils using this species as sentinel.

Antioxidant and oxidative stress related responses in the Mediterranean land snail Cantareus apertus exposed to the carbamate pesticide Carbaryl

The aim of the present work was to study the alterations of the antioxidant defenses and the overall susceptibility to oxidative stress of the terrestrial snail Cantareus apertus exposed to the carbamate pesticide Carbaryl at a low environmentally realistic concentration.The animals were exposed to Lactuca sativa soaked for 1h in 1μM Carbaryl. The temporal dynamics of the responses was assessed by measurements at 3, 7 and 14days of exposure.C. apertus exposed to Carbaryl activates a number of enzymatic antioxidant responses, represented by the early induction of catalase, glutathione peroxidase, glutathione reductase, followed by a delayed induction of superoxide dismutase. Concomitantly, a derangement of the total oxyradical scavenging of the tissues was observed, suggesting an overall impairment of the tissue capability to neutralize ROS probably resulting from the overall negative balance between enzymatic antioxidant defense capability and oxidative stress intensity. This negative balance exposed the animals to the risk of oxidative stress damages including genotoxic damage. Compared to acetylcholinesterase inhibition, the antioxidant responses developed to Carbaryl exposure at the low concentration utilized showed a greater percentage variation in exposed organisms.The results pointed out the high sensitivity of the antioxidant and oxidative stress related responses to Carbaryl exposure at an environmental realistic concentration, demonstrating their usefulness in environmental monitoring and risk assessment. The study highlights also the usefulness of the terrestrial snail C. apertus as potential bioindicator species for assessing the risk of pesticide environmental contamination.

The sound of a snail: two cases of acoustic defence in gastropods

The sound of a snail: two cases of acoustic defence in gastropods

Obtention du cycle de vie complet d' Helix aperta Born de sites tunisiens en conditions contrôlées. Influence de la photopériode

The present work revealed that growth and reproduction of Helix aperta (syn. Cantareus apertus), sampled at the end of summer in the region of Bazina (Tunisia), are stimulated by short-day photoperiod (SD 8hL–16hD) and inhibited by long-day photoperiod (LD 18hL–6hD). Indeed, under SD at 20 °C, 80% humidity and ad libitum Helixal® snail food, 2 generations (F1, F2) were obtained in 10 months with no refractory period. The effects of photoperiod on growth were found to be reversible and appeared after a time lag of 4 and 8 weeks for stimulation by SD and the inhibition by LD respectively. To cite this article: A. de Vaufleury, F. Gimbert, C. R. Biologies 332 (2009).

Heat shock protein response during estivation in the Mediterranean Grunt Snail (Cantareus apertus)

Heat shock protein response during estivation in the Mediterranean Grunt Snail (Cantareus apertus)

Heat shock proteins (Hsp70) and water content in the estivating Mediterranean Grunt Snail ( Cantareus apertus)

Pulmonate land snails often are able to estivate to survive dry hot seasons were water and food are scarce. The aperture of the shell is closed with an epiphragm, and metabolism is depressed to approximately one fourth of basal metabolism. We investigated a molecular aspect of estivation focussing on the heat shock protein 70 (Hsp70) stress response during estivation in the Mediterranean Grunt Snail Cantareus apertus. Sequences of a new inducible hsp70 and of actin are presented and expression of the hsp70 gene as well as Hsp70 protein content was measured in estivating animals. Both Hsp70 protein and mRNA do not show a significant change from the control, although there is a trend that hsp70 mRNA is less abundant in estivating specimens. After heat shock, the expression of hsp70 increased and a higher Hsp70 protein content was detected. Water relations were also investigated. After a period of 6 months in the dormant state, the snails contained 14% less water than active ones, implying a constricted protection against desiccation, compared to the desert snail Sphincterochila zonata, and a Mediterranean-type water economy.