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Sample records for lymnaeid snail species

  1. Morphological and molecular characterization of lymnaeid snails and their potential role in transmission of Fasciola spp. in Vietnam.

    Science.gov (United States)

    Dung, Bui Thi; Doanh, Pham Ngoc; The, Dang Tat; Loan, Ho Thi; Losson, Bertrand; Caron, Yannick

    2013-12-01

    Freshwater snails of the family Lymnaeidae play an important role in the transmission of fascioliasis worldwide. In Vietnam, 2 common lymnaeid species, Lymnaea swinhoei and Lymnaea viridis, can be recognized on the basis of morphology, and a third species, Lymnaea sp., is known to exist. Recent studies have raised controversy about their role in transmission of Fasciola spp. because of confusion in identification of the snail hosts. The aim of this study is, therefore, to clarify the identities of lymnaeid snails in Vietnam by a combination of morphological and molecular approaches. The molecular analyses using the second internal transcribed spacer (ITS2) of the nuclear ribosomal DNA clearly showed that lymnaeids in Vietnam include 3 species, Austropeplea viridis (morphologically identified as L. viridis), Radix auricularia (morphologically identified as L. swinhoei) and Radix rubiginosa (morphologically identified as Lymnaea sp.). R. rubiginosa is a new record for Vietnam. Among them, only A. viridis was found to be infected with Fasciola spp. These results provide a new insight into lymnaeid snails in Vietnam. Identification of lymnaeid snails in Vietnam and their role in the liver fluke transmission should be further investigated.

  2. Fasciola hepatica and lymnaeid snails occurring at very high altitude in South America.

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    Mas-Coma, S; Funatsu, I R; Bargues, M D

    2001-01-01

    Fascioliasis due to the digenean species Fasciola hepatica has recently proved to be an important public health problem, with human cases reported in countries of the five continents, including severe symptoms and pathology, with singular epidemiological characteristics, and presenting human endemic areas ranging from hypo- to hyperendemic. One of the singular epidemiological characteristics of human fascioliasis is the link of the hyperendemic areas to very high altitude regions, at least in South America. The Northern Bolivian Altiplano, located at very high altitude (3800-4100 m), presents the highest prevalences and intensities of human fascioliasis known. Sequences of the internal transcribed spacers ITS-1 and ITS-2 of the nuclear ribosomal DNA of Altiplanic Fasciola hepatica and the intermediate snail host Lymnaea truncatula suggest that both were recently introduced from Europe. Studies were undertaken to understand how the liver fluke and its lymnaeid snail host adapted to the extreme environmental conditions of the high altitude and succeeded in giving rise to high infection rates. In experimental infections of Altiplanic lymnaeids carried out with liver fluke isolates from Altiplanic sheep and cattle, the following aspects were studied: miracidium development inside the egg, infectivity of miracidia, prepatent period, shedding period, chronobiology of cercarial emergence, number of cercariae shed by individual snails, survival of molluscs at the beginning of the shedding process, survival of infected snails after the end of the shedding period and longevity of shedding and non-shedding snails. When comparing the development characteristics of European F. hepatica and L. truncatula, a longer cercarial shedding period and a higher cercarial production were observed, both aspects related to a greater survival capacity of the infected lymnaeid snails from the Altiplano. These differences would appear to favour transmission and may be interpreted as strategies

  3. Phylogeography and genetic divergence of some lymnaeid snails, intermediate hosts of human and animal fascioliasis with special reference to lymnaeids from the Bolivian Altiplano.

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    Jabbour-Zahab, R; Pointier, J P; Jourdane, J; Jarne, P; Oviedo, J A; Bargues, M D; Mas-Coma, S; Anglés, R; Perera, G; Balzan, C; Khallayoune, K; Renaud, F

    1997-04-15

    A population genetic study using starch gel electrophoresis was performed on populations of several species of lymnaeid snails acting as intermediate hosts for Fasciola hepatica (Trematoda, Plathyhelminth). Lymnaea viatrix was collected in 16 sites from the Bolivian Northern Altiplano. L. cubensis were obtained in one site from Venezuela, one site from Guadeloupe, three sites from Cuba and one site from the Dominican Republic. L. truncatula were collected in one site from France, one from Portugal and one from Morocco. Multilocus enzyme electrophoresis (MEE) were determined for 282 snails at 18 loci. A complete monomorphism was encountered at each geographic site. However, among these 18 loci, 13 are polymorphic and low and high levels of genetic divergence were observed between samples. Two genotypic groups can be differentiated by their multilocus genotypes. The western genotypic group associates together samples from Venezuela, Guadeloupe, Cuba and Dominican Republic (L. cubensis) while samples from France, Portugal and Morocco (L. truncatula) belong to the eastern genotypic group. Surprisingly, the Northern Bolivian Altiplano populations (L. viatrix) do not present any genetic divergence with the Portuguese sample. Therefore, the Bolivian snails belong entirely to the eastern genetic group. Within each group slight genetic divergences were observed. These results strongly support the European origin of the lymnaeid snails from the Northern Bolivian Altiplano.

  4. Molecular characterization of cryptic and sympatric lymnaeid species from the Galba/Fossaria group in Mendoza Province, Northern Patagonia, Argentina

    Science.gov (United States)

    2013-01-01

    Background Freshwater lymnaeid snails can act as the intermediate hosts for trematode parasites such as the liver fluke Fasciola hepatica, that cause significant economic and biomedical burden worldwide, particularly through bovine fascioliasis. Transmission potential is tightly coupled to local compatibility with snail hosts, so accurate identification of lymnaeid species is crucial for understanding disease risk, especially when invasive species are encountered. Mendoza Province, in Argentina, is a center of livestock production and also an area of endemic fascioliasis transmission. However, the distribution of lymnaeid species in the region is not well known. Methods This study examined lymnaeid snails from seven localities in the Department of Malarguë, Mendoza Province, using morphological and molecular analyses and also describing ecological variables associated with snail presence. Results While morphological characters identified two species of lymnaeid, Galba truncatula and G. viatrix, molecular data revealed a third, cryptic species, G. neotropica, which was sympatric with G. viatrix. G. truncatula was exclusively found in high altitude (>1900 meters above sea level [masl]) sites, whereas mixed G. neotropica/G. viatrix localities were at middle elevations (1300–1900 masl), and G. viatrix was found alone at the lowest altitude sites (variables while avoiding nomenclature redundancy. As the three species observed here, including one alien invasive species, are considered hosts of varying susceptibility to Fasciola parasites, and given the economic importance of fascioliasis for livestock production, this research has critical importance for the ultimate aim of controlling disease transmission. PMID:24499569

  5. Role of the lymnaeid snail Pseudosuccinea columella in the transmission of the liver fluke Fasciola hepatica in Egypt.

    Science.gov (United States)

    Dar, Y; Vignoles, P; Rondelaud, D; Dreyfuss, G

    2015-11-01

    Experimental infections of three Egyptian Pseudosuccinea columella populations with sympatric miracidia of Fasciola sp., coming from cattle- or sheep-collected eggs, were carried out to determine the capacity of this lymnaeid to support larval development of the parasite. Using microsatellite markers, the isolates of Egyptian miracidia were identified as Fasciola hepatica. Apart from being independent of snail origin, prevalences ranging from 60.4 to 75.5% in snails infected with five miracidia of F. hepatica were significantly higher than values of 30.4 to 42.2% in snails with bi-miracidial infections. The number of metacercariae ranged from 243 to 472 per cercarial-shedding snail and was independent of snail origin, parasite origin and miracidial dose used for infection. If P. columella was subjected to two successive bi-miracidial infections with F. hepatica, prevalence of infection was 63.3%, with a mean of 311 metacercariae per snail. These values were clearly greater than those already reported for Radix natalensis infected with the same parasite and the same protocol. Successful experimental infection of P. columella with F. hepatica suggests that this lymnaeid snail is an important intermediate host for the transmission of fascioliasis in Egypt.

  6. An optimized DNA extraction and multiplex PCR for the detection of Fasciola sp. in lymnaeid snails.

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    Caron, Y; Righi, S; Lempereur, L; Saegerman, C; Losson, B

    2011-05-31

    This study deals with the development and validation of an original PCR protocol to assess the presence of Fasciola hepatica in Galba truncatula its main intermediate host in Western Europe. In the present study two DNA extraction techniques are compared and a new multiplex PCR is described. The Chelex(®) DNA extraction technique showed to be more appropriate than the classical Phenol/Chloroform/Proteinase K based method because of the absence of toxic organic solvent, shorter duration and lower cost, and a higher reproducibility regarding DNA concentrations and wavelength ratios. The multiplex PCR was set up to amplify the lymnaeid internal transcribed spacer 2 sequence (500-600 bp) that act as an internal control and a 124 bp Fasciola sp. sequence that is repeated more than 300,000 times in fluke whole genome. Ninety six snails were pooled and 6 snails (6.25%) found positive for Fasciola sp. The limit of detection is lower than the minimal biological infestation unit (one miracidium). DNA extracts from Paramphistomum daubneyi, Dicrocoelium lanceolatum, and Fascioloides magna did not cross react.

  7. Natural prevalence in Cuban populations of the lymnaeid snail Galba cubensis infected with the liver fluke Fasciola hepatica: small values do matter.

    Science.gov (United States)

    Vázquez, Antonio A; Sánchez, Jorge; Alba, Annia; Pointier, Jean-Pierre; Hurtrez-Boussès, Sylvie

    2015-11-01

    Natural infections of lymnaeid snails by Fasciola hepatica are of primary importance to study transmission. Also, infected snails in the field can be used to explore the existing compatibility in host-parasite interactions. This paper aimed to describe the infection rate of Galba cubensis populations in fasciolosis transmission areas. Eight sites were sampled in western Cuba and 24 infected snails at six sites were found. The mean prevalence was 2.94% and the maximum value was 11.4%. The intensity of parasite infection was assessed as the number of rediae inside a single snail. High variation within the sites examined was observed, but a maximum of 76 rediae was recovered from one individual. Although the presence of two other trematode families (Schistosomatidae and Paramphistomatidae) was discovered in dissected individuals, no co-infection with F. hepatica was observed. This is the first time a study of natural prevalence of F. hepatica infection is carried out in Cuba, considered a hyper endemic country for bovine fasciolosis. Our results suggest that fasciolosis transmission may occur even when the number of infected snails remains relatively low.

  8. Insights into the relationships of Palearctic and Nearctic lymnaeids (Mollusca : Gastropoda by rDNA ITS-2 sequencing and phylogeny of stagnicoline intermediate host species of Fasciola hepatica

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    Bargues M.D.

    2003-09-01

    Full Text Available Fascioliasis by Fasciola hepatica is the vector-borne disease presenting the widest latitudinal, longitudinal and altitudinal distribution known. F. hepatica shows a great adaptation power to new environmental conditions which is the consequence of its own capacities together with the adaptation and colonization abilities of its specific vector hosts, freshwater snails of the family Lymnaeidae. Several lymnaeid species only considered as secondary contributors to the liver fluke transmission have, however, played a very important role in the geographic expansion of this disease. Many of them belong to the so-called "stagnicoline" type group. Stagnicolines have, therefore, a very important applied interest in the Holarctic region, to which they are geographically restricted. The present knowledge on the genetics of stagnicolines and on their parasite-host interrelationships is, however, far from being sufficient. The present paper analyses the relationships between Palaearctic and Nearctic stagnicoline species on the base of the new light furnished by the results obtained in nuclear rDNA ITS-2 sequencing and corresponding phylogenetic studies of the lymnaeid taxa Lymnaea (Stagnicola occulta, L. (S. palustris palustris (topotype specimens and L.(S. p. turricula from Europe. Natural infections with F. hepatica have been reported in all of them. Surprisingly, ITS-2 length and G C content of L. occulta were similar and perfectly fitted within the respective ranges known in North American stagnicolines. Nucleotide differences and genetic distances were higher between L. occulta and the other European stagnicolines than between L. occulta and the North American ones. The ITS-2 sequence of L. p. turricula from Poland differed from the other genotypes known from turricula in Europe. The phylogenetic trees using the maximum-parsimony, distance and maximum-likelihood methods confirmed (i the inclusion of L. occulta in the branch of North American

  9. Unusual snail species involved in the transmission of Fasciola hepatica in watercress beds in central France

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    Dreyfuss G.

    2002-06-01

    Full Text Available Four freshwater pulmonate species (Lymnaea ovata, L. stagnalis, Physa acuta, Planorbis leucostomawere living in several watercress beds known for their relationships with human cases of fasciolosis, whereas L. truncatula was never found. The aims of these studies were to determine the prevalence of natural infections with Fasciola hepatica in snails and to verify if these species might ensure the full larval development of this trematode (with cercarial shedding] when they were experimentally subjected to F. hepatica only, or to co-infections with an other trematode species. Investigations were so carried out in six snail populations living in watercress beds (including three for P. acuta and in four others originating from three brooks or a pond (as controls. Snails naturally infected with F. hepatica were found in two watercress beds inhabited by L. ovata (prevalence of infection: 1.4 % and P. leucostoma (0.1 %, respectively. The L. ovata from the watercress bed could be infected at a higher size than those from the control population and the prevalence of this infection was greater in the bed population. Similar findings were noted for L. stagnalis. Despite single or dual infections, the results obtained with the four populations of P. acuta were unsuccessful. In contrast, the co-infections of young P. leucostoma with Paramphistomum daubneyi and F. hepatica resulted in the shedding of some F. hepatica cercariae. According to the authors, the occurrence of fasciolosis in these watercress beds would be the consequence of frequent natural encounters between parasite and snails (L. ovata, L. stagnalis, or of co-infections with P. daubneyi and F. hepatica (P. leucostoma. In watercress beds only colonized by P. acuta, a lymnaeid species would have ensured the larval development of F. hepatica but it would have been eliminated by P. acuta, as this last species was known to be invasive and could colonize open drainage ditches on siliceous soil.

  10. Lymnaea schirazensis, an overlooked snail distorting fascioliasis data: genotype, phenotype, ecology, worldwide spread, susceptibility, applicability.

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    Bargues, María Dolores; Artigas, Patricio; Khoubbane, Messaoud; Flores, Rosmary; Glöer, Peter; Rojas-García, Raúl; Ashrafi, Keyhan; Falkner, Gerhard; Mas-Coma, Santiago

    2011-01-01

    Lymnaeid snails transmit medical and veterinary important trematodiases, mainly fascioliasis. Vector specificity of fasciolid parasites defines disease distribution and characteristics. Different lymnaeid species appear linked to different transmission and epidemiological patterns. Pronounced susceptibility differences to absolute resistance have been described among lymnaeid populations. When assessing disease characteristics in different endemic areas, unexpected results were obtained in studies on lymnaeid susceptibility to Fasciola. We undertook studies to understand this disease transmission heterogeneity. A ten-year study in Iran, Egypt, Spain, the Dominican Republic, Mexico, Venezuela, Ecuador and Peru, demonstrated that such heterogeneity is not due to susceptibility differences, but to a hitherto overlooked cryptic species, Lymnaea schirazensis, confused with the main vector Galba truncatula and/or other Galba/Fossaria vectors. Nuclear rDNA and mtDNA sequences and phylogenetic reconstruction highlighted an old evolutionary divergence from other Galba/Fossaria species, and a low intraspecific variability suggesting a recent spread from one geographical source. Morphometry, anatomy and egg cluster analyses allowed for phenotypic differentiation. Selfing, egg laying, and habitat characteristics indicated a migration capacity by passive transport. Studies showed that it is not a vector species (n = 8572 field collected, 20 populations): snail finding and penetration by F. hepatica miracidium occur but never lead to cercarial production (n = 338 experimentally infected). This species has been distorting fasciolid specificity/susceptibility and fascioliasis geographical distribution data. Hence, a large body of literature on G. truncatula should be revised. Its existence has henceforth to be considered in research. Genetic data on livestock, archeology and history along the 10,000-year post-domestication period explain its wide spread from the Neolithic

  11. A novel monoclonal antibody-based immunoenzymatic assay for epidemiological surveillance of the vector snails of Fasciola hepatica (Trematoda: Digenea).

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    Alba, Annia; Hernández, Hilda M; Marcet, Ricardo; Vázquez, Antonio A; Figueredo, Mabel; Sánchez, Jorge; Otero, Oscar; Sarracent, Jorge

    2015-02-01

    Fasciolosis is a globally distributed snail-borne disease which requires economic consideration due to its enormous impact on veterinary medicine. During recent decades, this parasitosis has also shown increasing prevalence in human populations worldwide. The dissemination and successful transmission of fasciolosis ultimately depends on the existence of susceptible snails that act as intermediate hosts. Therefore, to accomplish effective control of this disease, surveillance and detection of the infected intermediate host would be essential. The screening of trematodes within snails using classical parasitological examination of the larvae can be unreliable (sensitivity and specificity vary depending on the time of infection and the experience of the observer) and relatively costly when using molecular biological methods during large-scale monitoring. Here we propose a novel monoclonal antibody-based immunoenzymatic assay to detect ongoing Fasciola hepatica infection in lymnaeid snails. Anti-F. hepatica rediae mouse monoclonal antibodies were generated and used to develop a double monoclonal antibody-based ELISA for parasite detection. Fasciola hepatica-infected and uninfected laboratory-reared Galba cubensis and Pseudosuccinea columella were used for assessment of the developed ELISA. Experimentally infected snails were dissected and examined for parasite larvae as the "gold standard" method. Sensitivity results were 100% for both snail species, while specificity was 98% for G. cubensis and 100% for P. columella. No cross-reactivity was detected in lymnaeids infected with Trichobilharzia sp. or Cotylophoron sp. The ELISA enabled detection of the infection from day 8 p.i. in G. cubensis while in P. columella it was noted as early as day 4. To our knowledge no previous immunoassays have been reported to detect helminth-infected snails and the developed sandwich ELISA method is therefore suggested for infection status validation in natural populations of lymnaeid

  12. Adaptation of Lymnaea fuscus and Radix balthica to Fasciola hepatica through the experimental infection of several successive snail generations.

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    Rondelaud, Daniel; Titi, Amal; Vignoles, Philippe; Mekroud, Abdeslam; Dreyfuss, Gilles

    2014-07-01

    High prevalence of Fasciola hepatica infection (>70%) was noted during several outbreaks before the 2000s in several French farms where Galba truncatula is lacking. Other lymnaeids such as Lymnaea fuscus, L. glabra and/or Radix balthica are living in meadows around these farms but only juvenile snails can sustain complete larval development of F. hepatica while older snails were resistant. The low prevalence of infection (<20%) and limited cercarial production (<50 cercariae per infected snail) noted with these juveniles could not explain the high values noted in these cattle herds. As paramphistomosis due to Calicophoron daubneyi was not still noted in these farms, the existence of another mode of infection was hypothesized. Experimental infection of several successive generations of L. glabra, originating from eggs laid by their parents already infected with this parasite resulted in a progressive increase in prevalence of snail infection and the number of shed cercariae. The aim of this paper was to determine if this mode of snail infection was specific to L. glabra, or it might occur in other lymnaeid species such as L. fuscus and R. balthica. Five successive generations of L. fuscus and R. balthica were subjected to individual bimiracidial infections in the laboratory. Resulting rediae and cercariae in the first four generations were counted after snail dissection at day 50 p.e. (20°C), while the dynamics of cercarial shedding was followed in the F5 generation. In the first experiment, prevalence and intensity of F. hepatica infection in snails progressively increased from the F1 (R. balthica) or F2 (L. fuscus) generation. In the second experiment, the prevalence of F. hepatica infection and the number of shed cercariae were significantly lower in L. fuscus and R. balthica (without significant differences between both lymnaeids) than in G. truncatula. The F. hepatica infection of several successive snail generations, coming from parents infected with this

  13. Effects of an exotic prey species on a native specialist: example of the snail kite

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    Cattau, Christopher E.; Martin, J.; Kitchens, Wiley M.

    2010-01-01

    Despite acknowledging that exotic species can exhibit tremendous influence over native populations, few case studies have clearly demonstrated the effects of exotic prey species on native predators. We examined the effects of the recently introduced island apple snail (Pomacea insularum) on the foraging behavior and energetics of the endangered snail kite (Rostrhamus sociabilis plumbeus) in Florida. We conducted time-activity budgets: (i) on kites foraging for native Florida apple snails (Pomacea paludosa) in major wetland units within the kites' range that had not been invaded by the exotic island apple snail and (ii) on kites foraging for exotic apple snails in Lake Tohopekaliga, the only major wetland utilized by the snail kite that had suffered a serious invasion of P. insularum. When foraging for P. insularum, snail kites dropped a greater proportion of snails, and they experienced increased handling times and decreased consumption rates; however, kites foraging for P. insularum also spent a smaller proportion of the day in flight. Estimates of net daily energy balances between kites feeding on P. insularum versus P. paludosa were comparable for adults, but juveniles experienced energetic deficiencies when feeding on the exotic snail. Due to this discrepancy, we hypothesize that wetlands invaded by P. insularum, such as Lake Tohopekaliga, may function as ecological traps for the snail kite in Florida by attracting breeding adults but simultaneously depressing juvenile survival. This study highlights the conservation implications and importance of elucidating the effects that exotic species have on native specialists, especially those that are endangered, because subtle influences on behavior may have significant population consequences.

  14. Effects of an exotic prey species on a native specialist: Eexample of the snail kite

    Science.gov (United States)

    Cattau, Christopher E.; Martin, J.; Kitchens, W.M.

    2010-01-01

    Despite acknowledging that exotic species can exhibit tremendous influence over native populations, few case studies have clearly demonstrated the effects of exotic prey species on native predators. We examined the effects of the recently introduced island apple snail (Pomacea insularum) on the foraging behavior and energetics of the endangered snail kite (Rostrhamus sociabilis plumbeus) in Florida. We conducted time-activity budgets: (i) on kites foraging for native Florida apple snails (Pomacea paludosa) in major wetland units within the kites' range that had not been invaded by the exotic island apple snail and (ii) on kites foraging for exotic apple snails in Lake Tohopekaliga, the only major wetland utilized by the snail kite that had suffered a serious invasion of P. insularum. When foraging for P. insularum, snail kites dropped a greater proportion of snails, and they experienced increased handling times and decreased consumption rates; however, kites foraging for P. insularum also spent a smaller proportion of the day in flight. Estimates of net daily energy balances between kites feeding on P. insularum versus P. paludosa were comparable for adults, but juveniles experienced energetic deficiencies when feeding on the exotic snail. Due to this discrepancy, we hypothesize that wetlands invaded by P. insularum, such as Lake Tohopekaliga, may function as ecological traps for the snail kite in Florida by attracting breeding adults but simultaneously depressing juvenile survival. This study highlights the conservation implications and importance of elucidating the effects that exotic species have on native specialists, especially those that are endangered, because subtle influences on behavior may have significant population consequences. ?? 2009 Elsevier Ltd.

  15. Lymnaea schirazensis, an Overlooked Snail Distorting Fascioliasis Data: Genotype, Phenotype, Ecology, Worldwide Spread, Susceptibility, Applicability

    Science.gov (United States)

    Bargues, María Dolores; Artigas, Patricio; Khoubbane, Messaoud; Flores, Rosmary; Glöer, Peter; Rojas-García, Raúl; Ashrafi, Keyhan; Falkner, Gerhard; Mas-Coma, Santiago

    2011-01-01

    Background Lymnaeid snails transmit medical and veterinary important trematodiases, mainly fascioliasis. Vector specificity of fasciolid parasites defines disease distribution and characteristics. Different lymnaeid species appear linked to different transmission and epidemiological patterns. Pronounced susceptibility differences to absolute resistance have been described among lymnaeid populations. When assessing disease characteristics in different endemic areas, unexpected results were obtained in studies on lymnaeid susceptibility to Fasciola. We undertook studies to understand this disease transmission heterogeneity. Methodology/Principal Findings A ten-year study in Iran, Egypt, Spain, the Dominican Republic, Mexico, Venezuela, Ecuador and Peru, demonstrated that such heterogeneity is not due to susceptibility differences, but to a hitherto overlooked cryptic species, Lymnaea schirazensis, confused with the main vector Galba truncatula and/or other Galba/Fossaria vectors. Nuclear rDNA and mtDNA sequences and phylogenetic reconstruction highlighted an old evolutionary divergence from other Galba/Fossaria species, and a low intraspecific variability suggesting a recent spread from one geographical source. Morphometry, anatomy and egg cluster analyses allowed for phenotypic differentiation. Selfing, egg laying, and habitat characteristics indicated a migration capacity by passive transport. Studies showed that it is not a vector species (n = 8572 field collected, 20 populations): snail finding and penetration by F. hepatica miracidium occur but never lead to cercarial production (n = 338 experimentally infected). Conclusions/Significance This species has been distorting fasciolid specificity/susceptibility and fascioliasis geographical distribution data. Hence, a large body of literature on G. truncatula should be revised. Its existence has henceforth to be considered in research. Genetic data on livestock, archeology and history along the 10,000-year

  16. Lymnaea schirazensis, an overlooked snail distorting fascioliasis data: genotype, phenotype, ecology, worldwide spread, susceptibility, applicability.

    Directory of Open Access Journals (Sweden)

    María Dolores Bargues

    Full Text Available BACKGROUND: Lymnaeid snails transmit medical and veterinary important trematodiases, mainly fascioliasis. Vector specificity of fasciolid parasites defines disease distribution and characteristics. Different lymnaeid species appear linked to different transmission and epidemiological patterns. Pronounced susceptibility differences to absolute resistance have been described among lymnaeid populations. When assessing disease characteristics in different endemic areas, unexpected results were obtained in studies on lymnaeid susceptibility to Fasciola. We undertook studies to understand this disease transmission heterogeneity. METHODOLOGY/PRINCIPAL FINDINGS: A ten-year study in Iran, Egypt, Spain, the Dominican Republic, Mexico, Venezuela, Ecuador and Peru, demonstrated that such heterogeneity is not due to susceptibility differences, but to a hitherto overlooked cryptic species, Lymnaea schirazensis, confused with the main vector Galba truncatula and/or other Galba/Fossaria vectors. Nuclear rDNA and mtDNA sequences and phylogenetic reconstruction highlighted an old evolutionary divergence from other Galba/Fossaria species, and a low intraspecific variability suggesting a recent spread from one geographical source. Morphometry, anatomy and egg cluster analyses allowed for phenotypic differentiation. Selfing, egg laying, and habitat characteristics indicated a migration capacity by passive transport. Studies showed that it is not a vector species (n = 8572 field collected, 20 populations: snail finding and penetration by F. hepatica miracidium occur but never lead to cercarial production (n = 338 experimentally infected. CONCLUSIONS/SIGNIFICANCE: This species has been distorting fasciolid specificity/susceptibility and fascioliasis geographical distribution data. Hence, a large body of literature on G. truncatula should be revised. Its existence has henceforth to be considered in research. Genetic data on livestock, archeology and history

  17. Deterministic assembly of land snail communities according to species size and diet.

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    Schamp, Brandon; Horsák, Michal; Hájek, Michal

    2010-07-01

    1. We investigated whether coexisting snail species in 145 treeless fen communities in the Western Carpathian Mountains differed more in size and diet than would be expected by chance, as predicted for traits commonly associated with competition and differential resource acquisition under limiting similarity theory. 2. Contrary to expectations, coexisting snail species were no more different in body size than expected by chance under a null model. However, variation in body size played a significant role in structuring snail communities: coexisting snail species were significantly more similar with respect to body size. 3. We developed two new test statistics to expand our investigation of limiting similarity to include diet, a nominal trait. We tested whether communities of snails were characterized by a greater richness of diet, and whether different diets were represented more or less evenly within communities. Communities of snails were significantly less evenly distributed than expected by chance, with detritivores being over-represented relative to predatory strategies. 4. We also examined the effect of water pH and conductivity, herbaceous cover, and bryophyte and vascular plant richness, on these trends by examining how the effect size of our tests varied across these gradients. Convergence in species size increased with increasing habitat pH. Specifically, smaller snail species were over-represented in fen communities in general, and this effect was accentuated in increasingly calcareous fens. 5. Theory predicts that traits related strongly to environmental conditions are more likely to be convergent. Our findings support this suggestion, as small snail species have an advantage in tolerating freezing conditions over winter when refuges are limited. 6. These results add to the growing body of literature demonstrating that variation in body size and diet play a strong role in structuring communities, although frequently in ways not predicted by limiting

  18. Intermediate snail hosts of French Fasciola hepatica: Lymnaea neotropica and Lymnaea viatrix are better hosts than local Galba truncatula.

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    Sanabria, R; Mouzet, R; Courtioux, B; Vignoles, P; Rondelaud, D; Dreyfuss, G; Cabaret, J; Romero, J

    2012-11-01

    Allopatric and sympatric infections of Lymnaea neotropica and Lymnaea viatrix var. ventricosa with Argentinean and French isolates of Fasciola hepatica were carried out to determine the capacity of these snails to produce metacercariae and to verify if this capacity changed with snail generation. The same process was also made with a French population of Galba truncatula known to be highly susceptible to French isolates of the parasite. In each lymnaeid species separately considered, the survival rate at day 30 post-exposure and prevalence of F. hepatica infection in the group infected with Argentinean miracidia were significantly greater than those recorded in the corresponding French one. Compared to infected G. truncatula, both South American lymnaeids had longer patent periods and produced a higher number of metacercariae. The highest infections were noted with L. v. ventricosa. In the three snail species, metacercarial production was more important with the Argentinean isolate of miracidia than with the French one. If three successive generations of L. v. ventricosa are exposed to the same French isolate of miracidia, cercarial production significantly increased from parents to the F2 generation, while the other characteristics of infection only showed insignificant variations. L. neotropica and L. v. ventricosa are better intermediate hosts for French F. hepatica than local G. truncatula. The numerical increase of shed cercariae in the F1 and F2 generations of L. v. ventricosa demonstrates a rapid adaptation of this species to the French isolate of the parasite.

  19. Organ- and species-specific accumulation of metals in two land snail species (Gastropoda, Pulmonata)

    Energy Technology Data Exchange (ETDEWEB)

    Boshoff, Magdalena, E-mail: magdalena.boshoff@ua.ac.be [University of Antwerp, Systemic Physiological and Ecotoxicological Research, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Jordaens, Kurt [Royal Museum for Central Africa (JEMU), Leuvensesteenweg 13, B-3080 Tervuren (Belgium); University of Antwerp, Evolutionary Ecology Group, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Backeljau, Thierry [University of Antwerp, Evolutionary Ecology Group, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Royal Belgian Institute of Natural Sciences (JEMU), Vautierstraat 29, B-1000 Brussels (Belgium); Lettens, Suzanna [Research Institute for Nature and Forest (INBO), Kliniekstraat 25, B-1070 Brussels (Belgium); Tack, Filip [Ghent University, Laboratory of Analytical Chemistry and Applied Ecochemistry, Coupure Links 265, B-9000 Ghent (Belgium); Vandecasteele, Bart [Institute for Agricultural and Fisheries Research (ILVO), Burg van Gansberghelaan 109, B-9820 Merelbeke (Belgium); De Jonge, Maarten; Bervoets, Lieven [University of Antwerp, Systemic Physiological and Ecotoxicological Research, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)

    2013-04-01

    In order to evaluate the usefulness of terrestrial gastropods as bioindicators there is a need for studies that simultaneously compare (1) concentrations of metals in reference and polluted plots, (2) species within the same polluted habitat, (3) metal accumulation patterns in different organs and (4) metal accumulation patterns in relation to soil physicochemical properties. This study aims to assess metal accumulation patterns in two land snail species. Instead of analyzing an organism as a whole, investigating the partitioning of metals in different organs can provide information on the actual toxicological relevant fractions. Therefore, concentrations of Ag, Cd, Cr, Cu, Ni and Zn were examined in five different organs of Cepaea nemoralis, as well as in the foot and the body of Succinea putris. Snails were sampled at four polluted dredged sediment disposal localities and three adjacent less polluted reference plots situated along waterways in Flanders, Belgium. Due to the small size and problematic dissection of S. putris only the concentrations in the foot of both species could be compared. For this reason only, C. nemoralis can be described as a better bioindicator species that allows a far more detailed analysis of organ metal accumulation. This study showed that organs other than the digestive gland may be involved in the immobilization and detoxification of metals. Furthermore, pH, soil fractionation (clay %, silt %, sand %) and organic matter, correlate with metal accumulation in organs. However, most often the soil metal concentrations did not correlate with the concentrations found in snail organs. Metal concentrations in organs of both species (1) differed among polluted plots but rarely between polluted and reference plots within a locality, (2) were organ-specific (digestive gland > foot > albumen gland = spermoviduct = ovotestis), (3) were species-specific and (4) depended on the metal type (high Cd and Cu concentrations were observed in the

  20. Compatibility of Ugandan Schistosoma mansoni isolates with Biomphalaria snail species from Lake Albert and Lake Victoria

    DEFF Research Database (Denmark)

    Adriko, Moses; Standley, Claire J.; Tinkitina, Benjamin

    2013-01-01

    In order to investigate the capacity of being intermediate host for Schistosoma mansoni, the Ugandan F1 generation of Biomphalaria snail species that were laboratory-bred from parent populations originally collected from either Lake Victoria or Lake Albert was challenged with sympatric and non......-sympatric S. mansoni isolates. After a prepatent period of 20 days, a daily 10-hourly snail shedding for cercariae was done to determine the infection rate, cercarial production per hour and survival period of infected snails. The study suggests that when parasite strains from a different geographical origin...... is used for infection, survival of infected snails increase, leading to an increased transmission potential. Although earlier literature had indicated that the Lake Victoria Biomphalaria sudanica is refractory to S. mansoni, we showed that all Ugandan Biomphalaria spp., including B. sudanica from all...

  1. Habitat characteristics for different freshwater snail species as determined biologically through macroinvertebrate information.

    Science.gov (United States)

    El-Khayat, Hanaa M M; Mahmoud, Kadria M A; Mostafa, Bayomy B; Tantawy, Ahmad A; El-Deeb, Fatma A; Ragb, Fawzy M; Ismail, Nahed M; El-Said, Kalil M; Taleb, Hoda M Abu

    2011-12-01

    Macro-invertebrates including freshwater snails collected from 643 sites over 8 successive seasons among the River Nile, branches, main canals and certain drains in eight Egyptian Governorates. Thirteen snail species and one bivalve species were identified. The most distributed were Lanistus carinatus and Physa acuta while the most abundant were Cleopatra bulimoides and Physa acuta during the whole study. The sites that harbored each snail species in all the examined water-courses were grouped seasonally and their biological assessment was determined by their minimum and maximum total point similarity percentage to that of the corresponded reference site and mean of the total points. Habitats for most snail species attained minimum total point's similarity percentage less than 21% (very poor habitat) during autumn and winter then spring while during summer very poor habitat was harbored by only few snail species. P. acuta was the only survived snails in habitat which attained 0 as a minimum total point's similarity percentage during two seasons and L. carinatus and Succinea cleopatra during one season. With respect to medically important snails very poor sites constituted 23% of Biomphalaria alexandrina sites, 14% of Lymnaea natalensis and 9.4% of Bulinus truncatus sites. The studied macroinvertebrate matrices, total number of organisms, taxa richness, the Ephemeroptera, Plecoptera, and Trichoptera (EPT) index, ratio of EPT index to chironomidae, ratio of scraper to filtering collector, contribution of dominant macroinvertebrate major group, comparison revealed descending tolerances from B. alexanrina followed by L. natalensis then B. truncates, but Hilsenhoff Biotic Index (HBI) showed the same tolerance to organic pollution.

  2. The Giant Snail Achatina fulica as a Candidate Species for Advanced Bioregenerative Life Support Systems

    Science.gov (United States)

    Verbitskaya, Olga; Manukovsky, Nickolay; Kovalev, Vladimir

    Maintenance of crew health is of paramount importance for long duration space missions. Weight loss, bone and calcium loss, increased exposure to radiation and oxidative stress are critical concerns that need to be alleviated. Rational nutrition is a resource for mitigating the influence of unfavorable conditions. The insufficiency of vegetarian diet has been examined by the Japanese, Chinese and U.S. developers of bioregenerative life support systems (BLSS). Hence, inclusion of animals such as silkworm in BLSS looks justified. The giant snail is currently under studying as a source of animal food and a species of reducing waste in BLSS. An experimental system to conduct cultivation of giant snail was developed. It was established that there are some reasons to use the giant snails in BLSS. It could be a source of delicious meat. A. fulica is capable of consuming a wide range of feedstuffs including plant residues. Cultivation of snail in the limited volume does not demand the big expenditures of labor. The production of crude edible biomass and protein of A. fulica was 60±15 g and 7±1.8 g respectively per 1 kg of consumed forage (fresh salad leaves, root and leafy tops of carrot). To satisfy daily animal protein needs (30-35 g) a crewman has to consume 260-300 g of snail meat. To produce such amount of snail protein it takes to use 4.3-5.0 kg of plant forage daily. The nutritional composition of A. fulica whole bodies (without shell) and a meal prepared in various ways was quantitatively determined. Protein, carbohydrate, fat acid and ash content percentages were different among samples prepared in various ways. The protein content was highest (68 %) in the dry sample washed with CH3 COOH solution. Taking into consideration the experimental results a conceptual configuration of BLSS with inclusion of giant snail was developed and mass flow rates between compartments were calculated. Keywords: animal food; protein; giant snail; BLSS; conceptual configuration.

  3. Population dynamics of intermediate snail hosts of Fasciola hepatica and some environmental factors in San Juan y Martinez municipality, Cuba

    Directory of Open Access Journals (Sweden)

    Roberto Cañete

    2004-05-01

    Full Text Available The variation of abundances of intermediate snail hosts of Fasciola hepatica in Cuba (Fossaria cubensis and Pseudosuccinea columella was studied during one year under natural conditions at five sampling sites in San Juan y Martinez municipality, Pinar del Rio province, Cuba. The effect of some environmental variables on the lymnaeid abundances was also studied. A canonical correspondence analysis showed that both species do not generally occur together in the same habitat and that most factors affect them in an opposite fashion, although both of them correlate positively through time to the diversity of the habitats. F. cubensis prefers the sites that are in or closer to the city whereas P. columella is more abundant in rural sites. Lymnaeid abundances are mainly affected by nitrite and nitrate concentrations as well as by the abundance of the thiarid Tarebia granifera. F. cubensis is more abundant in polluted habitats with low densities (or absence of T. granifera whereas P. columella prefers cleaner habitats and can coexist with the thiarid, even at its higher densities. The implications of divergent preferences of the two lymnaeids for the control of fasciolosis are discussed.

  4. Associations between patterns of human intestinal schistosomiasis and snail and mammal species richness in Uganda

    DEFF Research Database (Denmark)

    Stensgaard, Anna-Sofie; Kristensen, Thomas K.; Jørgensen, Aslak

    2016-01-01

    the distribution of human schistosomiasis and biogeographical patterns of freshwater snail and mammal species richness in Uganda. We found that the association between estimated snail richness and human infection was best described by a negative correlation in non-spatial bi- and multivariate logistic mixed effect...... models. However, this association lost significance after the inclusion of a spatial component in a full geostatistical model, highlighting the importance of accounting for spatial correlation to obtain more precise parameter estimates. Furthermore, we found no significant relationships between mammal...

  5. Chapter 2. Fasciola, lymnaeids and human fascioliasis, with a global overview on disease transmission, epidemiology, evolutionary genetics, molecular epidemiology and control.

    Science.gov (United States)

    Mas-Coma, Santiago; Valero, María Adela; Bargues, María Dolores

    2009-01-01

    spp. are distinguished from local and zonal overlaps in areas where both fasciolids co-exist. Genetic techniques applied to liver flukes in recent years that are useful to elucidate the genetic characteristics of the two fasciolids are reviewed. The intra-specific and inter-specific variabilities of 'pure'F. hepatica and 'pure'F. gigantica were ascertained by means of complete sequences of ribosomal deoxyribonucleic acid (rDNA) internal transcribed spacer (ITS)-2 and ITS-1 and mitochondrial deoxyribonucleic acid (mtDNA) cox1 and nad1 from areas with only one fasciolid species. Fasciolid sequences of the same markers scattered in the literature are reviewed. The definitive haplotypes established appear to fit the proposed global evolutionary scenario. Problems posed by fasciolid cross-breeding, introgression and hybridization in overlap areas are analyzed. Nuclear rDNA appears to correlate with adult fluke characteristics and fasciolid/lymnaeid specificity, whereas mtDNA does not. However, flukes sometimes appear so intermediate that they cannot be ascribed to either F. hepatica-like or F. gigantica-like forms and snail specificity may be opposite to the one deduced from the adult morphotype. The phenotypic characteristics of adults and eggs of 'pure'F. hepatica and F. gigantica, as well as of intermediate forms in overlap areas, are compared, with emphasis on the definitive host influence on egg size in humans. Knowledge is sufficient to support F. hepatica and F. gigantica as two valid species, which recently diverged by adaptation to different pecoran and lymnaeid hosts in areas with differing environmental characteristics. Their phenotypic differences and ancient pre-domestication origins involve a broad geographical area that largely exceeds the typical, more local scenarios known for sub-species units. Phenomena such as abnormal ploidy and aspermic parthenogenesis in hybrids suggest that their separate evolution in pre-domestication times allowed them to achieve

  6. Phylogeography in Nassarius mud snails: Complex patterns in congeneric species.

    Science.gov (United States)

    Pu, Chuanliang; Li, Haitao; Zhu, Aijia; Chen, Yiyong; Zhao, Yan; Zhan, Aibin

    2017-01-01

    One major goal for phylogeographical studies is to elucidate respective roles of multiple evolutionary and ecological forces that shape the current distribution patterns. In marine and coastal ecosystems, it has been generated a common realization that species with enormous population size and pelagic larval stages can disperse across broad geographical scales, leading to weak or even no phylogeographical structure across large geographical scales. However, the violation of such realization has been frequently reported, and it remains largely unexplored on mechanisms responsible for various phylogeographical patterns observed in different species at varied geographical scales. Here, we used a species-rich genus Nassarius to assess and compare phylogeographical patterns in congeneric species, and discuss causes and consequences underlying varied phylogeographical patterns. Interestingly, we observed complex phylogeographical patterns both within single species and across multiple species, and multiple analyses showed varied levels of genetic heterogeneity among sites within and across species. Available evidence suggests that related species with similar biological characteristics may not be necessary to result in consistent phylogeographical patterns. Multiple factors, including larval ecology, interactions between dispersal and natural selection, and human activity-mediated dispersal, can partially explain the complex patterns observed in this study. Deep investigations should be performed on these factors, particularly their respective roles in determining evolutionary/ecological processes to form phylogeographical patterns in species with high dispersal capacities in marine and coastal ecosystems.

  7. Nutritional status of four species of giant land snails in Nigeria

    Institute of Scientific and Technical Information of China (English)

    FAGBUARO O.; OSO J.A.; EDWARD J.B.; OGUNLEYE R.F.

    2006-01-01

    Four species of African giantl and snails(Archachatina marginata(ovum)Pfeiffer,Archachatina marginata(saturalis)Philippi, Achatina achatina and Limicolaria spp.) were assessed for their proximate and mineral compositions aimed at establishing their nutritive values on wet weight basis. Analysis of muscle revealed that composition of crude protein varied from 18.66%±0.57% in Limicolaria spp. and 20.56%±0.05% in Archachatina marginata (ovum) Pfeiffer; moisture content was 76.56% ±0.04% in Archachatina marginata (ovum) Pfeiffer and 78.68%±0.68% in Limicolaria spp. and ash was 1.34% ±0.02% in Achatina achatina and 1.44%±0.01% in Archachatina marginata (ovum) Pfeiffer. These values were statistically different from each other (P<0.05). Carbohydrate and fat content were generally low. Crude fibre was not detected in any of the species.The concentrations of zinc, iron, manganese, magnesium, calcium, phosphorus, sulphur, potassium and sodium in the flesh of the snails were determined. Values of iron, magnesium, calcium, phosphorus, potassium and sodium were consistently high while cobalt, copper and lead were not detected. Snails complement the required trace and minor elements needed for proper growth and development in human being, so it is recommended for regular consumption.

  8. Three new species of cercariae from Melanopsis praemorsa (L. 1758, Buccinum) snails in Al-Bathan fresh water body, Palestine

    Institute of Scientific and Technical Information of China (English)

    Sami Bdir; Ghaleb Adwan

    2012-01-01

    Objective: To investigate other new species of cercariae encountered in Melanopsis praemorsa (M. praemorsa) snails collected from Palestine. Methods: A total of 1 100 M. praemorsa were collected from Al-Bathan water body, Palestine, from November, 2010 to November, 2011. Cercariae in M. praemorsa were obtained by emerging and crushing methods. Results: Other three new different species of cercariae have been identified from this snail. These species were Xiphidiocercaria (Cercaria melanopsi palestinia IV), Microcercous (Cercaria melanopsi palestinia V) and Longifurcate cercaria (Cercaria melanopsi palestinia VI). The infection rate ofM. praemorsa with these three different cercariae was (42.2%). Coinfection with Xiphidiocercariae and Longifurcate cercariae or Xiphidiocercariae and Microcercous cercariae has been noted and coinfection rate was 1.23% among the infected snails. The highest cercarial infection rate was in June (64.3%). No infected snails were found in September. It was also noted that infected snails attained a larger size than uninfected ones and all infected snails had a size between 17-22 mm (average 20 mm). Conclusions: Our studies imply that there are potentially more new species of trematodes in this area than were found until now. Due to the presence of infected M. praemorsa and may be species of other snails, water resources could be contaminated by the emerging new cercariae, consequently attack the local people directly via the skin or are transferred to them by metacercariae ingestion. More surveys are needed to identify the real prevalence of the trematodes both in human and animal hosts, and also to determine the range of snail hosts of the parasite in enzootic areas of the disease, as well as the life cycle and biology of trematodes and its effects on man should be elucidated.

  9. Elevated Snail Expression Mediates Tumor Progression in Areca Quid Chewing-Associated Oral Squamous Cell Carcinoma via Reactive Oxygen Species

    Science.gov (United States)

    Lee, Shiuan-Shinn; Tsai, Chung-Hung; Yu, Cheng-Chia; Chang, Yu-Chao

    2013-01-01

    Background Snail is an important transcription factor implicated in several tumor progression and can be induced by reactive oxygen species (ROS). Areca quid chewing is a major risk factor of oral squamous cell carcinoma (OSCC). Therefore, we hypothesize that the major areca nut alkaloid arecoline may induce Snail via ROS and involve in the pathogenesis of areca quid chewing-associated OSCC. Methodology/Principal Finding Thirty-six OSCC and ten normal oral epithelium specimens were examined by immunohistochemistry and analyzed by the clinico-pathological profiles. Cytotoxicity, 2′, 7′-dichlorofluorescein diacetate assay, and western blot were used to investigate the effects of arecoline in human oral keratinocytes (HOKs) and oral epithelial cell line OECM-1 cells. In addition, antioxidants N-acetyl-L-cysteine (NAC), curcumin, and epigallocatechin-3 gallate (EGCG) were added to find the possible regulatory mechanisms. Initially, Snail expression was significantly higher in OSCC specimens (pArecoline enhanced the generation of intracellular ROS at the concentration higher than 40 µg/ml (pArecoline was also found to induced Snail expression in a dose- and time-dependent manner (parecoline induced Snail expression (pArecoline-upregulated Snail expression may be mediated by ROS generation. In addition, arecoline induced Snail expression was downregulated by NAC, curcumin, and EGCG. PMID:23874481

  10. Exploring species level taxonomy and species delimitation methods in the facultatively self-fertilizing land snail genus Rumina (gastropoda: pulmonata.

    Directory of Open Access Journals (Sweden)

    Vanya Prévot

    Full Text Available Delimiting species in facultatively selfing taxa is a challenging problem of which the terrestrial pulmonate snail genus Rumina is a good example. These snails have a mixed breeding system and show a high degree of shell and color variation. Three nominal species (R. decollata, R. saharica and R. paivae and two color morphs within R. decollata (dark and light are currently recognized. The present study aims at evaluating to what extent these entities reflect evolutionary diverging taxonomic units, rather than fixed polymorphisms due to sustained selfing. Therefore, a phylogenetic analysis of nuclear (ITS1, ITS2 and mitochondrial DNA (COI, CytB, 12S rDNA, 16S rDNA sequences was performed. Putative species in Rumina, inferred from the mitochondrial DNA phylogeny, were compared with those proposed on the basis of the COI gene by (1 DNA barcoding gap analysis, (2 Automatic Barcode Gap Discovery, (3 the species delimitation plug-in of the Geneious software, (4 the Genealogical Sorting Index, and (5 the General Mixed Yule Coalescent model. It is shown that these methods produce a variety of different species hypotheses and as such one may wonder to what extent species delimitation methods are really useful. With respect to Rumina, the data suggest at least seven species, one corresponding to R. saharica and six that are currently grouped under the name R. decollata. The species-level status of R. paivae is rejected.

  11. Muscadine grape skin extract reverts snail-mediated epithelial mesenchymal transition via superoxide species in human prostate cancer cells.

    Science.gov (United States)

    Burton, Liza J; Barnett, Petrina; Smith, Basil; Arnold, Rebecca S; Hudson, Tamaro; Kundu, Kousik; Murthy, Niren; Odero-Marah, Valerie A

    2014-03-12

    Snail transcription factor can induce epithelial-mesenchymal transition (EMT), associated with decreased cell adhesion-associated molecules like E-cadherin, increased mesenchymal markers like vimentin, leading to increased motility, invasion and metastasis. Muscadine grape skin extract (MSKE) has been shown to inhibit prostate cancer cell growth and induce apoptosis without affecting normal prostate epithelial cells. We investigated novel molecular mechanisms by which Snail promotes EMT in prostate cancer cells via Reactive Oxygen Species (ROS) and whether it can be antagonized by MSKE. ARCaP and LNCaP cells overexpressing Snail were utilized to examine levels of reactive oxygen species (ROS), specifically, superoxide, in vitro using Dihydroethidium (DHE) or HydroCy3 dyes. Mitosox staining was performed to determine whether the source of ROS was mitochondrial in origin. We also investigated the effect of Muscadine grape skin extract (MSKE) on EMT marker expression by western blot analysis. Migration and cell viability using MTS proliferation assay was performed following MSKE treatments. Snail overexpression in ARCaP and LNCaP cells was associated with increased concentration of mitochondrial superoxide, in vitro. Interestingly, MSKE decreased superoxide levels in ARCaP and LNCaP cells. Additionally, MSKE and Superoxide Dismutase (SOD) reverted EMT as evidenced by decreased vimentin levels and re-induction of E-cadherin expression in ARCaP-Snail cells after 3 days, concomitant with reduced cell migration. MSKE also decreased Stat-3 activity in ARCaP-Snail cells. This study shows that superoxide species may play a role in Snail transcription factor-mediated EMT. Therefore, therapeutic targeting of Snail with various antioxidants such as MSKE may prove beneficial in abrogating EMT and ROS-mediated tumor progression in human prostate cancer.

  12. Muscadine grape skin extract reverts snail-mediated epithelial mesenchymal transition via superoxide species in human prostate cancer cells

    Science.gov (United States)

    2014-01-01

    Background Snail transcription factor can induce epithelial-mesenchymal transition (EMT), associated with decreased cell adhesion-associated molecules like E-cadherin, increased mesenchymal markers like vimentin, leading to increased motility, invasion and metastasis. Muscadine grape skin extract (MSKE) has been shown to inhibit prostate cancer cell growth and induce apoptosis without affecting normal prostate epithelial cells. We investigated novel molecular mechanisms by which Snail promotes EMT in prostate cancer cells via Reactive Oxygen Species (ROS) and whether it can be antagonized by MSKE. Methods ARCaP and LNCaP cells overexpressing Snail were utilized to examine levels of reactive oxygen species (ROS), specifically, superoxide, in vitro using Dihydroethidium (DHE) or HydroCy3 dyes. Mitosox staining was performed to determine whether the source of ROS was mitochondrial in origin. We also investigated the effect of Muscadine grape skin extract (MSKE) on EMT marker expression by western blot analysis. Migration and cell viability using MTS proliferation assay was performed following MSKE treatments. Results Snail overexpression in ARCaP and LNCaP cells was associated with increased concentration of mitochondrial superoxide, in vitro. Interestingly, MSKE decreased superoxide levels in ARCaP and LNCaP cells. Additionally, MSKE and Superoxide Dismutase (SOD) reverted EMT as evidenced by decreased vimentin levels and re-induction of E-cadherin expression in ARCaP-Snail cells after 3 days, concomitant with reduced cell migration. MSKE also decreased Stat-3 activity in ARCaP-Snail cells. Conclusions This study shows that superoxide species may play a role in Snail transcription factor-mediated EMT. Therefore, therapeutic targeting of Snail with various antioxidants such as MSKE may prove beneficial in abrogating EMT and ROS-mediated tumor progression in human prostate cancer. PMID:24617993

  13. Elevated snail expression mediates tumor progression in areca quid chewing-associated oral squamous cell carcinoma via reactive oxygen species.

    Directory of Open Access Journals (Sweden)

    Shiuan-Shinn Lee

    Full Text Available BACKGROUND: Snail is an important transcription factor implicated in several tumor progression and can be induced by reactive oxygen species (ROS. Areca quid chewing is a major risk factor of oral squamous cell carcinoma (OSCC. Therefore, we hypothesize that the major areca nut alkaloid arecoline may induce Snail via ROS and involve in the pathogenesis of areca quid chewing-associated OSCC. METHODOLOGY/PRINCIPAL FINDING: Thirty-six OSCC and ten normal oral epithelium specimens were examined by immunohistochemistry and analyzed by the clinico-pathological profiles. Cytotoxicity, 2', 7'-dichlorofluorescein diacetate assay, and western blot were used to investigate the effects of arecoline in human oral keratinocytes (HOKs and oral epithelial cell line OECM-1 cells. In addition, antioxidants N-acetyl-L-cysteine (NAC, curcumin, and epigallocatechin-3 gallate (EGCG were added to find the possible regulatory mechanisms. Initially, Snail expression was significantly higher in OSCC specimens (p<0.05. Elevated Snail expression was associated with lymph node metastasis (p = 0.031 and poor differentiation (p = 0.017. Arecoline enhanced the generation of intracellular ROS at the concentration higher than 40 µg/ml (p<0.05. Arecoline was also found to induced Snail expression in a dose- and time-dependent manner (p<0.05. Treatment with NAC, curcumin, and EGCG markedly inhibited arecoline induced Snail expression (p<0.05. CONCLUSION/SIGNIFICANCE: Our results suggest that Snail overexpression in areca quid chewing-associated OSCC is associated with tumors differentiation and lymph node metastasis. Arecoline-upregulated Snail expression may be mediated by ROS generation. In addition, arecoline induced Snail expression was downregulated by NAC, curcumin, and EGCG.

  14. Characterisation of fascioliasis lymnaeid intermediate hosts from Chile by DNA sequencing, with emphasis on Lymnaea viator and Galba truncatula.

    Science.gov (United States)

    Artigas, Patricio; Bargues, M Dolores; Mera y Sierra, Roberto L; Agramunt, Veronica H; Mas-Coma, Santiago

    2011-12-01

    In South America, Fasciola hepatica infection poses serious health problems in both humans and livestock. In Chile, the medical impact appears yearly stable and mainly concentrated in central regions, where the veterinary problem is highlighted by higher animal prevalences. Studies were undertaken by rDNA ITS-2 and ITS-1 and mtDNA cox1 sequencing to clarify the specific status of the lymnaeids, their geographical distribution and fascioliasis transmission capacity in Chile, by comparison with other American countries and continents. Results change the lymnaeid scenario known so far. The lymnaeid fauna of mainland Chile shows to be poor, including only two authochthonous species, Lymnaea viator and Pectinidens diaphana, and a third introduced species of Palaearctic origin Galba truncatula. Both Lymnaea lebruni and Lymnaea patagonica proved to be synonyms of P. diaphana. G. truncatula appears to have always been confused with L. viator and seems distributed from Región VI to Región IX, overlapping with human endemic areas. DNA sequencing results suggest that the absence of correlation between remote sensing data and disease prevalences could be due to transmission capacity differences between L. viator and G. truncatula. Results furnish a new baseline on which to undertake future appropriate studies on transmission, epidemiology and control.

  15. Comparative evaluation of haemagglutination potential of haemolymph from two species of giant African land snails (Archachatina marginata and Achatina achatina).

    Science.gov (United States)

    Abiona, John Adesanya; Akinduti, Paul Akinniyi; Oyekunle, Mufutao Atanda; Osinowo, Olusegun Ayodeji; Onagbesan, A Okanlawon Mohammed

    2014-05-01

    A comparative study was conducted to evaluate haemagglutination potential in the haemolymph of two species of giant African land snails (Archachatina marginata and Achatina achatina). Three liveweight groups of snails (150 g) were used with 4 replicates per liveweight per species for haemagglutination assay (HA). The effect of aestivation on haemagglutination potential was also evaluated. Erythrocytes (2%) from cattle, sheep, goat and chicken were used for HA assay. Results showed that agglutinin-like substances that agglutinate erythrocytes of sheep, goat, cattle and chicken were present in the haemolymph of the two species of giant African land snails. Effect of species was found to be significant (P Snail liveweight had no significant effect (P > 0.05) on agglutinin content of the haemolymph in both species. Agglutination level depended on the source of erythrocyte used. Sheep erythrocyte recorded the highest haemagglutination titre, followed by goat, cattle, and chicken in that order. To our knowledge, this is the first evidence that Giant African land snails (GALS) haemolymph contain agglutinins as previously reported for Helix species. This evidence may be the basis for its survivability in the wild and thus establish the use of GALS for African herbal medicinal applications.

  16. Unimodal latitudinal pattern of land-snail species richness across northern Eurasian lowlands.

    Science.gov (United States)

    Horsák, Michal; Chytrý, Milan

    2014-01-01

    Large-scale patterns of species richness and their causes are still poorly understood for most terrestrial invertebrates, although invertebrates can add important insights into the mechanisms that generate regional and global biodiversity patterns. Here we explore the general plausibility of the climate-based "water-energy dynamics" hypothesis using the latitudinal pattern of land-snail species richness across extensive topographically homogeneous lowlands of northern Eurasia. We established a 1480-km long latitudinal transect across the Western Siberian Plain (Russia) from the Russia-Kazakhstan border (54.5°N) to the Arctic Ocean (67.5°N), crossing eight latitudinal vegetation zones: steppe, forest-steppe, subtaiga, southern, middle and northern taiga, forest-tundra, and tundra. We sampled snails in forests and open habitats each half-degree of latitude and used generalized linear models to relate snail species richness to climatic variables and soil calcium content measured in situ. Contrary to the classical prediction of latitudinal biodiversity decrease, we found a striking unimodal pattern of snail species richness peaking in the subtaiga and southern-taiga zones between 57 and 59°N. The main south-to-north interchange of the two principal diversity constraints, i.e. drought stress vs. cold stress, explained most of the variance in the latitudinal diversity pattern. Water balance, calculated as annual precipitation minus potential evapotranspiration, was a single variable that could explain 81.7% of the variance in species richness. Our data suggest that the "water-energy dynamics" hypothesis can apply not only at the global scale but also at subcontinental scales of higher latitudes, as water availability was found to be the primary limiting factor also in this extratropical region with summer-warm and dry climate. A narrow zone with a sharp south-to-north switch in the two main diversity constraints seems to constitute the dominant and general pattern of

  17. Unimodal latitudinal pattern of land-snail species richness across northern Eurasian lowlands.

    Directory of Open Access Journals (Sweden)

    Michal Horsák

    Full Text Available Large-scale patterns of species richness and their causes are still poorly understood for most terrestrial invertebrates, although invertebrates can add important insights into the mechanisms that generate regional and global biodiversity patterns. Here we explore the general plausibility of the climate-based "water-energy dynamics" hypothesis using the latitudinal pattern of land-snail species richness across extensive topographically homogeneous lowlands of northern Eurasia. We established a 1480-km long latitudinal transect across the Western Siberian Plain (Russia from the Russia-Kazakhstan border (54.5°N to the Arctic Ocean (67.5°N, crossing eight latitudinal vegetation zones: steppe, forest-steppe, subtaiga, southern, middle and northern taiga, forest-tundra, and tundra. We sampled snails in forests and open habitats each half-degree of latitude and used generalized linear models to relate snail species richness to climatic variables and soil calcium content measured in situ. Contrary to the classical prediction of latitudinal biodiversity decrease, we found a striking unimodal pattern of snail species richness peaking in the subtaiga and southern-taiga zones between 57 and 59°N. The main south-to-north interchange of the two principal diversity constraints, i.e. drought stress vs. cold stress, explained most of the variance in the latitudinal diversity pattern. Water balance, calculated as annual precipitation minus potential evapotranspiration, was a single variable that could explain 81.7% of the variance in species richness. Our data suggest that the "water-energy dynamics" hypothesis can apply not only at the global scale but also at subcontinental scales of higher latitudes, as water availability was found to be the primary limiting factor also in this extratropical region with summer-warm and dry climate. A narrow zone with a sharp south-to-north switch in the two main diversity constraints seems to constitute the dominant and

  18. Radix dolgini: The integrative taxonomic approach supports the species status of a Siberian endemic snail (Mollusca, Gastropoda, Lymnaeidae).

    Science.gov (United States)

    Vinarski, Maxim V; Aksenova, Olga V; Bespalaya, Yulia V; Bolotov, Ivan N; Schniebs, Katrin; Gofarov, Mikhail Yu; Kondakov, Alexander V

    2016-01-01

    The molecular techniques are the standard tool for the study of the taxonomic position and phylogenetic affinities of the lymnaeid genus Radix Montfort, 1810, and the majority of the European representatives of this taxon have been studied in this respect. However, a plethora of nominal species of Radix described from Northern Asia (Siberia and the Russian Far East) are still characterized only morphologically, raising some doubts concerning their validity. In this paper, we present the triple (morphological, molecular, and zoogeographical) evidence that there is at least one endemic species of Radix, Radix dolgini (Gundrizer and Starobogatov, 1979), widely distributed in Siberia and Western Mongolia. Phylogenetically, it is a sister species to the European R. labiata (Rossmaessler, 1835) [=R. peregra auct.], and their common ancestor most probably lived in the Pliocene, nearly 3.25Myr ago. Our results assume the existence of an extended dispersal barrier for freshwater hydrobionts between Europe and Siberia in the Late Pliocene that may be important for biogeographical explanations. Three other nominal Siberian species of Radix: R. kurejkae (Gundrizer and Starobogatov, 1979), R. gundrizeri (Kruglov and Starobogatov, 1983), and R. ulaganica (Kruglov and Starobogatov, 1983) proved to be the junior synonyms of R. dolgini.

  19. Opisthorchis viverrini: Implications of the systematics of first intermediate hosts, Bithynia snail species in Thailand and Lao PDR.

    Science.gov (United States)

    Kiatsopit, Nadda; Sithithaworn, Paiboon; Saijuntha, Weerachai; Petney, Trevor N; Andrews, Ross H

    2013-03-01

    Bithynia snails are important hosts of the human liver fluke, Opisthorchis viverrini. Allozyme markers were used to examine genetic variation and the systematics of Bithynia snails from different geographical localities in Thailand and Lao PDR. Our results show that Bithynia siamensis goniomphalos contains two major evolutionary clades with at least nine morphologically similar but genetically distinct "cryptic" species (taxa). Clade A consists of snails from the Chi and the Mun River wetlands, Thailand and clade B consists of snails from the Nam Ngum River wetland, Lao PDR, as well as snails from some localities in the Songkram River wetland, Thailand. There is an association between O. viverrini cryptic taxa with B. s. goniomphalos cryptic taxa within the defined wetlands. Bithynia species are the critical amplifying component of O. viverrini and they control transmission from humans to fish second intermediate hosts. These findings are particularly important for understanding the transmission dynamics of O. viverrini. They are, in addition, a link in the life cycle of O. viverrini which can be used for developing and implementing programs to eliminate and control opisthorchiasis and its associated cholangiocarcinoma.

  20. Multiple genes elucidate the evolution of venomous snail-hunting Conus species.

    Science.gov (United States)

    Nam, Hannah H; Corneli, Patrice Showers; Watkins, Maren; Olivera, Baldomero; Bandyopadhyay, Pradip

    2009-12-01

    The species-rich Cone snails (Conus sp.) are predatory, marine gastropods known for small venom peptides that are valuable for pharmacological research applications. Phylogenetic analyses with mitochondrial rRNA sequences have facilitated peptide discovery. However, these relatively conserved genes leave unresolved the closer relationships among many species. We sequenced 26 internal transcribed spacer 2 (ITS2) sequences from genomic ribosomal DNA to elucidate the evolutionary relationships among molluscivorous species and to piscivorous and vermivorous species. We show that ITS2 sequences are well conserved within species but are sufficiently variable among species to resolve recent divergences. Using Bayesian, maximum likelihood and log-determinant methods, we use the ITS sequences to resolve portions of the tree that could not be resolved using the more conventional mt rRNA sequences. When the ITS2 sequences are added to existing COI and to the more conserved rRNA sequences and then properly modeled, support throughout the tree is increased. This enables us to show finer relationships among the molluscivorous species that reveal three well-supported clades (Conus, Cylinder, and Darioconus) and renders the ITS2 sequences an essential component in advancing the discovery and pharmacological characterization of novel peptides from the venoms of these molluscs.

  1. Fasciola hepatica infections in cattle and the freshwater snail Galba truncatula from Dakhla Oasis, Egypt.

    Science.gov (United States)

    Arafa, W M; Hassan, A I; Snousi, S A M; El-Dakhly, Kh M; Holman, P J; Craig, T M; Aboelhadid, S M

    2017-02-06

    Infection by Fasciola species was investigated in seven districts of Dakhla Oasis, Egypt, through abattoir inspection of cattle livers for adult worms and sedimentation of faecal samples from local cattle to detect Fasciola eggs. In addition, lymnaeid snails collected from the study area were examined microscopically for developmental stages of Fasciola spp. Abattoir inspection revealed that 51 out of 458 cattle livers (11.1%) contained adult flukes, which were identified morphologically as Fasciola hepatica. Examination of the cattle faecal samples revealed that 142 out of 503 (28.2%) contained Fasciola eggs. The collected snails, identified as Galba truncatula and Radix natalensis, showed larval stages of Fasciola in 71 out of 731 (9.7%) G. truncatula, while R. natalensis showed no infection. Specific duplex polymerase chain reaction (PCR) targeting the mitochondrial cox1 gene of F. hepatica and Fasciola gigantica was carried out on DNA extracted from pooled infected snails and adult worms. The F. hepatica size amplicon (1031 bp) was obtained from both the infected G. truncatula and the adult worms isolated from cattle livers from different districts. The amplicon sequences were identical to the published sequences of F. hepatica mitochondrial cox1 gene. In conclusion, the zoonotic importance of Fasciola infection and appropriate hygienic measures must be taken into consideration in Dakhla Oasis, Egypt.

  2. PCR diagnosis of Fasciola hepatica in field-collected Lymnaea columella and Lymnaea viatrix snails.

    Science.gov (United States)

    Cucher, Marcela A; Carnevale, Silvana; Prepelitchi, Lucila; Labbé, Jorge H; Wisnivesky-Colli, Cristina

    2006-04-15

    Fasciolosis, caused by the trematode Fasciola hepatica, is a zoonosis of economic importance in livestock that is emerging as a chronic disease in humans. The intermediate hosts are lymnaeid snails, in which diagnosis of infection is traditionally based on cercarial shedding, tissue sectioning and crushing. We developed a PCR assay for the sensitive and specific detection of F. hepatica in field-collected Lymnaea sp. snails. A primer pair was designed to amplify a 405 bp fragment of the cytochrome c oxidase subunit 1 gene of F. hepatica. The PCR assay showed a limit of detection of 10 pg of genomic F. hepatica DNA. No cross-reactions were observed with samples from other related trematode species or from the snail hosts Lymnaea columella and Lymnaea viatrix. DNA sequencing of the amplicon showed 100% homology with F. hepatica, and 75-89% homology with other trematodes on regions that did not include the entire set of primers. Two samples from Argentina were analysed. For snails in sample 1 (n = 240), identified as L. columella, the infection rate was 17.5 and 51.3% by direct examination and PCR, respectively. For snails in sample 2 (n = 34), identified as L. viatrix, the infection rate was 2.9 and 61.8% by direct examination and PCR, respectively. Differences in infection rates between these diagnosis methods were significant for both samples. Our PCR technique showed to be effective for detecting specific F. hepatica infections of low intensity in the intermediate host, and hence it could be used to study the epidemiological situation in a given area, as well as to assess host suitability for the parasite.

  3. Fasciola hepatica in Cuba: compatibility of different isolates with two intermediate snail hosts, Galba cubensis and Pseudosuccinea columella.

    Science.gov (United States)

    Vázquez, A A; Sánchez, J; Pointier, J-P; Théron, A; Hurtrez-Boussès, S

    2014-12-01

    In Cuba, only two lymnaeid snails, Galba cubensis and Pseudosuccinea columella, with different ecology and distribution patterns, are intermediate hosts for Fasciola hepatica. The compatibility of these two species as hosts was analysed through their rates of infection, the production of rediae and survivorship when exposed to F. hepatica miracidia. Ten populations of G. cubensis, eight of P. columella collected from various habitats and six isolates of F. hepatica sampled in slaughterhouses from different localities were tested. Our results clearly demonstrate that G. cubensis is a more compatible host for F. hepatica in Cuba when compared with P. columella. However, the role that P. columella may have in fascioliasis transmission under certain conditions should not be disregarded. Variation in infectivity among isolates of F. hepatica were also observed and may explain why some regions in Cuba are more commonly subjected to fascioliasis outbreaks.

  4. Feeding behavior of black carp Mylopharyngodon piceus (Pisces: Cyprinidae) on fry of other fish species and trematode transmitting snail species

    DEFF Research Database (Denmark)

    Hung, Nguyen Manh; The, Dang Tat; Stauffer, Jay R.

    2014-01-01

    Fish raised in aquaculture ponds may get infected with fishborne zoonotic trematodes (FZT) during the nursing stage. Freshwater snails serve as intermediate hosts for FZT and we wanted to explore the possibility of controlling snails by stocking nursery ponds with a few juvenile specimens...... offered snails as food; the odds of survival of fry from tanks with medium sized and large black carp was 5.6% and 39.9%, respectively of that of fry in tanks with small sized black carp. Since the large black carp also consumed fewer snails than medium sized fish, we believe that large specimens were...... stressed in the experimental aquaria. Under semi-field conditions, presence of the black carp had no effect on survival of fry of Oreochromis niloticus and C. carpio both in the absence and presence of snails as alternative food. The black carp consumed most snails offered with the exception of some...

  5. Snail meat: Significance and consumption

    Directory of Open Access Journals (Sweden)

    Dragićević Olgica

    2005-01-01

    Full Text Available The consumption of snail meat goes back to prehistoric times. Different ancient nations had snails on their menu, but Helices culture as a productive activity was born as a Roman culture. Some of the most economically important edible species are: Helix aspersa (Mtiller Helixpomatia (Linne, Helix iucorum (Linne, Helix aperta (Born, Eobania vermiculata (Miiller. Together with its tasie, snail meat has several advantages over others: quite low lipid rate and calorie values versus rich mineral, essential amino acid and fatty acid content. The composition of snail meat is presented. In addition, the composition of different snail species and the part analyzed (pedal mass and visceral mass is presented. Also, the differences in composition according to the species (snail meat horse/chicken meat, beef, swine meat, fish meat are presented. The French are the world's leading consumers of snails. !n France snails come to market in a variety of ways. Estimated consumption of snails in France is around 40 000 tones/year. Total French imports account for 25% of world imports. France is also the leading exporter of prepared snails, mainly sold as preserved snails and prepared dishes. Snail imports have been much higher than exports (65 tones exported in 2002. vs. 2.700 tones imported. Despite the large consumption, only 3% of snails in France come from production (farming. Italy is in second place in the world consumption of snails, and Spain and Germany are in the third and fourth place. The development of snails consumption in Italy is followed with the same amount of production of snails in the whole biological circle. In 2001, from 24,700 tons, 9,350 tons (37.8% came from production, 6 00 tons (2.4% came from nature, and 14,750 tons (59.70% came from imports (frozen, fresh and prepared snails. In Serbia, at the beginning of 2005, we had over 400 registered farms for snail production.

  6. Seasonal transmission of Opisthorchis viverrini sensu lato and a lecithodendriid trematode species in Bithynia siamensis goniomphalos snails in northeast Thailand.

    Science.gov (United States)

    Namsanor, Jutamas; Sithithaworn, Paiboon; Kopolrat, Kulthida; Kiatsopit, Nadda; Pitaksakulrat, Opal; Tesana, Smarn; Andrews, Ross H; Petney, Trevor N

    2015-07-01

    Seasonal changes play roles in the transmission success of fish-borne zoonotic trematodes (FZT). This study examined the seasonal transmission patterns of Opisthorchis viverrini sensu lato (s.l.) and a virgulate cercaria (family Lecithodendriidae) in the snail intermediate host, Bithynia siamensis goniomphalos in northeast Thailand. Snail samples were collected monthly during the rainy, cool, and hot seasons during 2012-2013 to determine the prevalence and intensity of larval trematode infections. The prevalence of O. viverrini s.l. varied significantly with season, being 0.31%, 1.05%, and 0.37% in the rainy, cool, and hot seasons, respectively (P < 0.05). Similarly, the prevalence of virgulate cercariae was 3.11%, 6.80%, and 1.64% in the rainy, cool, and hot seasons, respectively (P < 0.05). The intensity of larval trematode infections also varied between seasons and peaked in the hot season (P < 0.05) in both species. The snails infected with O. viverrini s.l. were significantly smaller (P < 0.05) and those infected with virgulate cercariae were significantly larger (P < 0.05) than uninfected snails. Seasonal variation and the different sizes of B. s. goniomphalos parasitized by O. viverrini s.l. and virgulate trematodes indicate complex host-parasite interactions with important implications for the epidemiology of O. viverrini s.l.

  7. An artificial perch to help Snail Kites handle an exotic Apple Snail

    Science.gov (United States)

    Pias, Kyle E.; Welch, Zach C.; Kitchens, Wiley M.

    2012-01-01

    In the United States, the Snail Kite (Rostrhamus sociabilis plumbeus) is a federally endangered species and restricted to the wetlands of south-central Florida where the current population numbers less than 1,500. The Snail Kite is an extreme dietary specialist, previously feeding almost exclusively on one species of snail, the Florida Apple Snail (Pomacea paludosa). Within the past decade, an exotic species of apple snail, the Island Apple Snail (Pomacea insularum), has become established on lakes in central Florida. Island Apple Snails are larger than the native Florida Apple Snails, and Snail Kites handle the exotic snails less efficiently. Juvenile Snail Kites, in particular, have lower daily energy balances while feeding on Island Apple Snails. An inexpensive, easy-to-construct platform was developed that would provide Snail Kites with a flat, stable surface on which to extract snails. The platform has the potential to reduce the difficulties Snail Kites experience when handling exotic snails, and may benefit the Snail Kite population as a whole. Initial observations indicate that Snail Kites use the platforms frequently, and snails extracted at the platforms are larger than snails extracted at other perches.

  8. Anatomy of predator snail Huttonella bicolor, an invasive species in Amazon rainforest, Brazil (Pulmonata, Streptaxidae

    Directory of Open Access Journals (Sweden)

    Luiz Ricardo L. Simone

    2013-01-01

    Full Text Available The morpho-anatomy of the micro-predator Huttonella bicolor (Hutton, 1838 is investigated in detail. The species is a micro-predator snail, which is splaying in tropical and subtropical areas all over the world, the first report being from the Amazon Rainforest region of northern Brazil. The shell is very long, with complex peristome teeth. The radula bears sharp pointed teeth. The head lacks tentacles, bearing only ommatophores. The pallial cavity lacks well-developed vessels (except for pulmonary vessel; the anus and urinary aperture are on pneumostome. The kidney is solid, with ureter totally closed (tubular; the primary ureter is straight, resembling orthurethran fashion. The buccal mass has an elongated and massive odontophore, of which muscles are described; the odontophore cartilages are totally fused with each other. The salivary ducts start as one single duct, bifurcating only prior to insertion. The mid and hindguts are relatively simple and with smooth inner surfaces; there is practically no intestinal loop. The genital system has a zigzag-fashioned fertilization complex, narrow prostate, no bursa copulatrix, short and broad vas deferens, and simple penis with gland at distal tip. The nerve ring bears three ganglionic masses, and an additional pair of ventral ganglia connected to pedal ganglia, interpreted as odontophore ganglia. These features are discussed in light of the knowledge of other streptaxids and adaptations to carnivory.

  9. De Novo Transcriptome Characterization of a Sterilizing Trematode Parasite (Microphallus sp. from Two Species of New Zealand Snails

    Directory of Open Access Journals (Sweden)

    Laura Bankers

    2017-03-01

    Full Text Available Snail-borne trematodes represent a large, diverse, and evolutionarily, ecologically, and medically important group of parasites, often imposing strong selection on their hosts and causing host morbidity and mortality. Even so, there are very few genomic and transcriptomic resources available for this important animal group. We help to fill this gap by providing transcriptome resources from trematode metacercariae infecting two congeneric snail species, Potamopyrgus antipodarum and P. estuarinus. This genus of New Zealand snails has gained prominence in large part through the development of P. antipodarum and its sterilizing trematode parasite Microphallus livelyi into a textbook model for host–parasite coevolutionary interactions in nature. By contrast, the interactions between Microphallus trematodes and P. estuarinus, an estuary-inhabiting species closely related to the freshwater P. antipodarum, are relatively unstudied. Here, we provide the first annotated transcriptome assemblies from Microphallus isolated from P. antipodarum and P. estuarinus. We also use these transcriptomes to produce genomic resources that will be broadly useful to those interested in host–parasite coevolution, local adaption, and molecular evolution and phylogenetics of this and other snail–trematode systems. Analyses of the two Microphallus transcriptomes revealed that the two trematode types are more genetically differentiated from one another than are the M. livelyi infecting different populations of P. antipodarum, suggesting that the Microphallus infecting P. estuarinus represent a distinct lineage. We also provide a promising set of candidate genes likely involved in parasitic infection and response to salinity stress.

  10. Count your eggs before they invade: identifying and quantifying egg clutches of two invasive apple snail species (Pomacea.

    Directory of Open Access Journals (Sweden)

    Colin H Kyle

    Full Text Available Winning the war against invasive species requires early detection of invasions. Compared to terrestrial invaders, aquatic species often thrive undetected under water and do not garner notice until too late for early action. However, fortunately for managers, apple snails (Family Ampullariidae, Genus Pomacea provide their own conspicuous sign of invasion in the form of vibrantly colored egg clutches. Managers can potentially use egg clutches laid in the riparian zone as a means of early detection and species identification. To facilitate such efforts, we quantified differences in characteristics (length, width, depth, mass, egg number of field-laid clutches for the two most common invasive species of apple snail, P. canaliculata and P. maculata, in native and non-native populations. Pomacea canaliculata native and non-native populations differed noticeably only in width. Native P. maculata clutches possessed significantly greater width, mass and eggs numbers compared with native P. canaliculata. Non-native P. maculata clutches significantly exceeded all other populations in all measured characteristics. Consequently, these traits may successfully distinguish between species. Fecundity data also allowed us to develop models that accurately estimated the number of eggs per clutch for each species based on clutch dimensions. We tested one, two and three dimensional models of clutches, including rendering a clutch as either a complete ellipsoid or an ellipsoid intersected by a cylinder to represent the oviposition site. Model comparisons found the product of length and depth, with a different function for each population, best predicted egg number for both species. Comparisons of egg number to clutch volume and mass implied non-native P. canaliculata may be food limited, while non-native P. maculata appeared to produce such enormous clutches by having access to greater nutrients than the native population. With these new tools, researchers and

  11. A Record of Small-Clawed Otters (Aonyx cinereus) Foraging on an Invasive Pest Species, Golden Apple Snails (Pomacea canaliculata) in a West Sumatra Rice Field

    OpenAIRE

    Jabang; Wilson Novarino; Aadrean

    2011-01-01

    A small-clawed otter (Aonyx cinereus) survey in West Sumatran rice fields was conducted from April to September 2010. During this survey, golden apple snail (Pomacea canaliculata) shell remains were found on a rice field bank as suspected prey remains of small-clawed otters. This suspicion was later proved by the occurrence of snail material (pieces of operculum and shell) in otter spraints. This is the first evidence of small-clawed otters foraging on this invasive pest species. Characterist...

  12. Dynamic of population-dynamics in a medically important snail species Lymnaea (Radix Luteola (Lamarck

    Directory of Open Access Journals (Sweden)

    T. K. Misra

    1993-09-01

    Full Text Available The life-cycle parameters of the snail Lymnaea (Radix luteola and the factors influencing the same have been studied under laboratory conditions. Ins each month, from July 1990 to June 1991, a batch of 100 zero-day old individual were considered for studies. The snails of April batch survived for 19.42 days while those in December batch survived for 87.45 days. The May batch individual though survived for 65.67 days gained maximum shell size (15.84 mm in length and body weight (419.87 mg. All individuals of April batch died prior to attainment of sexual maturity. In the remaining 11 batches the snails became sexually mature between 32 and 53 days. At this stage, they were with varying shell lengths, 9.3 mm to 13,11 mm in respect to batches. The reproduction period varied from 1-67 days. An individual laid, on an average, 0,25 (March batch to 443.67 (May batch eggs in its life-span. A batch of such snails would leave 24312, 22520, 720268, 80408, 76067, 418165, 214, 9202, 0, 0, 2459386 and 127894 individuals at the end of 352nd day. Since the environmental conditions were almost similar the 'dynamic' of population dynamics seems to be involved with the 'strain' of the snail individuals of the batches concerned.

  13. Attraction to amino acids by Lymnaea acuminata, the snail host of Fasciola species.

    Science.gov (United States)

    Tiwari, F; Singh, D K

    2004-04-01

    Adult Lymnaea acuminata (average length 20-22 mm) were collected locally from lakes and low-lying submerged fields from Gorakhpur. The chemoattraction studies were made in round glass aquaria measuring 30 cm in diameter and filled to a depth of 10 mm with 500 ml dechlorinated tap water. Each aquarium was divided into four concentric zones. At the starting time of the assay 10 snails were placed on the circumference of outermost zone 0. Snail attractant pellets (SAP) were added simultaneously in the center of central zone 3. SAP of different amino acids were prepared at concentrations of 10, 20, 50, 80 and 100 mM/2% agar solution and, subsequently, spread to a uniform thickness of 5 mm. After cooling, SAP were cut in small pieces of 5 mm in diameter. Lymnaea acuminata's attraction to amino acids was studied using different amino acid concentrations in SAP. Pellets containing amino acids with non-polar R groups (proline and tryptophan), a charged polar group (arginine) and uncharged polar R groups (serine, citrulline and asparagine) were tested. The snails were more attracted to the uncharged polar R group amino acid serine than to other groups of amino acids. The preferred amino acid concentration was 80 mM. The attraction of snails to different amino acids was concentration dependent. Snails could discriminate amongst the different amino acids at > or = 50 mM.

  14. Attraction to amino acids by Lymnaea acuminata, the snail host of Fasciola species

    Directory of Open Access Journals (Sweden)

    Tiwari F.

    2004-01-01

    Full Text Available Adult Lymnaea acuminata (average length 20-22 mm were collected locally from lakes and low-lying submerged fields from Gorakhpur. The chemoattraction studies were made in round glass aquaria measuring 30 cm in diameter and filled to a depth of 10 mm with 500 ml dechlorinated tap water. Each aquarium was divided into four concentric zones. At the starting time of the assay 10 snails were placed on the circumference of outermost zone 0. Snail attractant pellets (SAP were added simultaneously in the center of central zone 3. SAP of different amino acids were prepared at concentrations of 10, 20, 50, 80 and 100 mM/2% agar solution and, subsequently, spread to a uniform thickness of 5 mm. After cooling, SAP were cut in small pieces of 5 mm in diameter. Lymnaea acuminata's attraction to amino acids was studied using different amino acid concentrations in SAP. Pellets containing amino acids with non-polar R groups (proline and tryptophan, a charged polar group (arginine and uncharged polar R groups (serine, citrulline and asparagine were tested. The snails were more attracted to the uncharged polar R group amino acid serine than to other groups of amino acids. The preferred amino acid concentration was 80 mM. The attraction of snails to different amino acids was concentration dependent. Snails could discriminate amongst the different amino acids at > or = 50 mM.

  15. Molluscicidal activity of crude water and hexane extracts of Hypericum species to snails (Radix peregra).

    Science.gov (United States)

    Teixeira, Tânia; Rainha, Nuno; Rosa, José Silvino; Lima, Elisabete; Baptista, José

    2012-04-01

    In spite of intense research on both chemical constituency and biological activity of Hypericum species, potential applications of their active components for pest control have been less well investigated. In the present study, Hypericum androsaemum (tutsan), Hypericum foliosum (malfurada), and Hypericum undulatum (wavy St. John's wort) aqueous and hexane extracts were studied for their molluscicidal and ovicidal activities against Radix peregra. The molluscicidal activity of the aqueous extracts was low, except for H. androsaemum infusion (median lethal concentration [LC50](adults)  = 317.1 ppm; LC50(juveniles)  = 415 ppm), and less important compared with the toxicity of all three hexane extracts tested: H. androsaemum (LC50(adults)  = 30.47 ppm; LC50(juveniles)  = 73.25 ppm), H. undulatum (LC50(adults)  = 30.55 ppm; LC50(juveniles)  = 60.54 ppm), and H. foliosum (LC50(adults)  = 48.61 ppm; LC50(juveniles)  = 38.81 ppm). An ovicidal effect was observed only with H. androsaemum infusion (1.85% of hatching at 500 ppm) and H. foliosum hexane extract (0.0% of hatching at 100 ppm). A preliminary phytochemical investigation of the lipophylic extracts from these Hypericum sp. revealed a different chemical profile and confirmed the presence of ursolic acid only in H. undulatum as the main compound. The present study indicates that products from hexane extracts of the Hypericum sp. analyzed may be used as potential molluscicides to control snails responsible for transmitting fasciolosis.

  16. A new baseline for fascioliasis in Venezuela: lymnaeid vectors ascertained by DNA sequencing and analysis of their relationships with human and animal infection

    Science.gov (United States)

    2011-01-01

    Background Human and animal fascioliasis poses serious public health problems in South America. In Venezuela, livestock infection represents an important veterinary problem whereas there appear to be few human cases reported, most of which are passively detected in health centres. However, results of recent surveys suggest that the situation may be underestimated in particular areas. To obtain a baseline for future fascioliasis assessment, studies were undertaken by means of rDNA ITS-2 and ITS-1 and mtDNA cox1 sequencing to clarify the specific status of Venezuelan lymnaeids, their geographical distribution and fascioliasis transmission capacity, by comparison with other American countries and other continents. Results Results obtained completely change the lymnaeid scenario known so far. The relatively rich lymnaeid fauna of Venezuela has been proven to include (i) Lymnaea meridensis and L. neotropica as the only native members, (ii) L. cubensis and Pseudosuccinea columella introduced from the Caribbean area, and (iii) Galba truncatula and L. schirazensis introduced from the Old World. The absence of representatives of the stagnicoline and Radix groups is remarkable. Four species are fascioliasis vectors: G. truncatula, L. cubensis and L. neotropica, which have the capacity to give rise to human endemic areas, and P. columella, which is a source of animal infection and is responsible for the spread of disease. Vector capacity in the apparently highland endemic L. meridensis is to be confimed, although may be expected given its phylogenetic relationships. Similarly as elsewhere, the non-transmitting L. schirazensis has been confused with L. cubensis, also with G. truncatula and possibly with L. neotropica. Conclusions The new scenario leads to the re-opening of many disease aspects. In Venezuela, altitude appears to be the main factor influencing fascioliasis distribution. Human infection shows an altitude pattern similar to other Andean countries, although a

  17. Distribution Of The Freshwater Snail Species Fagotia (Gastropoda, Melanopsidae In Ukraine According To Climatic Factors. I. Fagotia Esperi

    Directory of Open Access Journals (Sweden)

    Tytar V.

    2015-08-01

    Full Text Available Maximum entropy niche modeling was employed as a tool to assess potential habitat suitability for the freshwater snail F. esperi (Férussac, 1823 in Ukraine for both contemporary climatic conditions and conditions projected for 2050. Of the 19 bioclimatic predictor variables used in the modeling, the “mean temperature seosonality” “mean temperature of driest quarter” and “precipitation of warmest quarter” were the three most important in predicting habitat suitability and distribution of this mollusk species.

  18. A new terrestrial snail species (Gastropoda: Bulimulidae from the Región de Antofagasta, northern Chile

    Directory of Open Access Journals (Sweden)

    Juan Francisco Araya

    2017-07-01

    Full Text Available A new species of Scutalus Albers, 1850 (Gastropoda: Bulimulidae, Scutalus chango sp. n., is described from a coastal area of northern Chile. Empty shells of this new species were found buried in sand and under boulders and rocks in the foothills of the Chilean Coastal Range at Paposo, Región de Antofagasta. This new species is distinguished from all other Chilean terrestrial snails by its slender shell with a flared and reflected aperture, and by the presence of a columellar fold. This is the first record of Scutalus in Chile, and the southernmost record for this endemic South American bulimulid genus. The presence of this species in Paposo highlights the need for further research and for conservation guidelines in coastal areas of northern Chile, which have comparatively high levels of biodiversity and endemism.

  19. Anatomy of predator snail Huttonella bicolor, an invasive species in Amazon rainforest, Brazil (Pulmonata, Streptaxidae

    Directory of Open Access Journals (Sweden)

    Luiz Ricardo L. Simone

    2013-01-01

    Full Text Available The morpho-anatomy of the micro-predator Huttonella bicolor (Hutton, 1838 is investigated in detail. The species is a micro-predator snail, which is splaying in tropical and subtropical areas all over the world, the first report being from the Amazon Rainforest region of northern Brazil. The shell is very long, with complex peristome teeth. The radula bears sharp pointed teeth. The head lacks tentacles, bearing only ommatophores. The pallial cavity lacks well-developed vessels (except for pulmonary vessel; the anus and urinary aperture are on pneumostome. The kidney is solid, with ureter totally closed (tubular; the primary ureter is straight, resembling orthurethran fashion. The buccal mass has an elongated and massive odontophore, of which muscles are described; the odontophore cartilages are totally fused with each other. The salivary ducts start as one single duct, bifurcating only prior to insertion. The mid and hindguts are relatively simple and with smooth inner surfaces; there is practically no intestinal loop. The genital system has a zigzag-fashioned fertilization complex, narrow prostate, no bursa copulatrix, short and broad vas deferens, and simple penis with gland at distal tip. The nerve ring bears three ganglionic masses, and an additional pair of ventral ganglia connected to pedal ganglia, interpreted as odontophore ganglia. These features are discussed in light of the knowledge of other streptaxids and adaptations to carnivory.A morfo-anatomia do micro-predador Huttonella bicollor (Hutton, 1838 é investigada em detalhe. A espécie é um caracol micro-predador que está se espalhando pelas áreas tropicais e subtropicais pelo mundo, sendo este o primeiro registro para a Floresta Amazônica, região Norte do Brasil. A concha é muito longa, com complexos dentes no perístoma. A rádula possui dentes pontiagudos. A cabeça carece de tentáculos, possuindo somente omatóforos. A cavidade palial carece de vasos bem desenvolvidos

  20. Experimental infection of the digeneans to some congeneric snail species radiated in a single water system: Relative importance of local evolution and phylogenetic constraint.

    Science.gov (United States)

    Urabe, Misako

    2016-06-01

    To determine the relative importance of local adaptation caused by host-parasite coevolution and resource tracking by the parasites, the susceptibility of the freshwater snail genus Semisulcospira to the digenean parasite genus Genarchopsis was investigated experimentally. Four snail species endemic to the Lake Biwa system in Japan and two non-endemic species were investigated. All but one species was also tested for local variation in susceptibility. Parasites were obtained from Takashima (mix population of Genarchopsis gigi and Genarchopsis chubuensis) and Nagahama (G. chubuensis). In endemic Semisulcospira, closely related specie pairs (Semisulcospira habei and Semisulcospira niponica, Semisulcospira decipiens and Semisulcospira nakasekoae) showed similar susceptibilities to parasites from both localities. S. habei and S. niponica were highly susceptible to parasites from Takashima, but were resistant to parasites from Nagahama. S. decipiens and S. nakasekoae showed moderate susceptibility to parasites from both localities. None of the endemic snail species showed a clear local variation in susceptibility. These results show that the susceptibility of endemic Semisulcospira to Genarchopsis is conservative and can be regarded as an example of resource-tracking. One of the non-endemic snails, Semisulcospira libertina, showed local variation in susceptibility. This variation was not related to the sympatry of the parasites used for the experimental infection, suggesting that it was not the result of local adaptation by parasites.

  1. Snail meat: Significance and consumption

    OpenAIRE

    Dragićević Olgica; Baltić Milan Ž.

    2005-01-01

    The consumption of snail meat goes back to prehistoric times. Different ancient nations had snails on their menu, but Helices culture as a productive activity was born as a Roman culture. Some of the most economically important edible species are: Helix aspersa (Mtiller) Helixpomatia (Linne), Helix iucorum (Linne), Helix aperta (Born), Eobania vermiculata (Miiller). Together with its tasie, snail meat has several advantages over others: quite low lipid rate and calorie values versus rich mine...

  2. Integrative Taxonomy of Southeast Asian Snail-Eating Turtles (Geoemydidae: Malayemys) Reveals a New Species and Mitochondrial Introgression.

    Science.gov (United States)

    Ihlow, Flora; Vamberger, Melita; Flecks, Morris; Hartmann, Timo; Cota, Michael; Makchai, Sunchai; Meewattana, Pratheep; Dawson, Jeffrey E; Kheng, Long; Rödder, Dennis; Fritz, Uwe

    2016-01-01

    Based on an integrative taxonomic approach, we examine the differentiation of Southeast Asian snail-eating turtles using information from 1863 bp of mitochondrial DNA, 12 microsatellite loci, morphology and a correlative species distribution model. Our analyses reveal three genetically distinct groups with limited mitochondrial introgression in one group. All three groups exhibit distinct nuclear gene pools and distinct morphology. Two of these groups correspond to the previously recognized species Malayemys macrocephala (Chao Phraya Basin) and M. subtrijuga (Lower Mekong Basin). The third and genetically most divergent group from the Khorat Basin represents a previously unrecognized species, which is described herein. Although Malayemys are extensively traded and used for religious release, only few studied turtles appear to be translocated by humans. Historic fluctuations in potential distributions were assessed using species distribution models (SDMs). The Last Glacial Maximum (LGM) projection of the predictive SDMs suggests two distinct glacial distribution ranges, implying that the divergence of M. macrocephala and M. subtrijuga occurred in allopatry and was triggered by Pleistocene climate fluctuations. Only the projection derived from the global circulation model MIROC reveals a distinct third glacial distribution range for the newly discovered Malayemys species.

  3. Adaptation of Lymnaea fuscus and Radix balthica to Fasciola hepatica through the experimental infection of several successive snail generations

    Science.gov (United States)

    2014-01-01

    Background High prevalence of Fasciola hepatica infection (>70%) was noted during several outbreaks before the 2000s in several French farms where Galba truncatula is lacking. Other lymnaeids such as Lymnaea fuscus, L. glabra and/or Radix balthica are living in meadows around these farms but only juvenile snails can sustain complete larval development of F. hepatica while older snails were resistant. The low prevalence of infection (hepatica infection in snails progressively increased from the F1 (R. balthica) or F2 (L. fuscus) generation. In the second experiment, the prevalence of F. hepatica infection and the number of shed cercariae were significantly lower in L. fuscus and R. balthica (without significant differences between both lymnaeids) than in G. truncatula. Conclusion The F. hepatica infection of several successive snail generations, coming from parents infected with this parasite, resulted in a progressive increase in prevalence and intensity of snail infection. This may explain high prevalence of fasciolosis noted in several cattle-breeding farms when the common snail host of this digenean, G. truncatula, is lacking. PMID:24986589

  4. Small Molecules in the Cone Snail Arsenal.

    Science.gov (United States)

    Neves, Jorge L B; Lin, Zhenjian; Imperial, Julita S; Antunes, Agostinho; Vasconcelos, Vitor; Olivera, Baldomero M; Schmidt, Eric W

    2015-10-16

    Cone snails are renowned for producing peptide-based venom, containing conopeptides and conotoxins, to capture their prey. A novel small-molecule guanine derivative with unprecedented features, genuanine, was isolated from the venom of two cone snail species. Genuanine causes paralysis in mice, indicating that small molecules and not just polypeptides may contribute to the activity of cone snail venom.

  5. Species-specific vulnerability of benthic marine embryos of congeneric snails (Haminoea spp.) to ultraviolet radiation and other intertidal stressors.

    Science.gov (United States)

    Russell, Janine; Phillips, Nicole

    2009-08-01

    We used field surveys and multi-factorial experiments to examine synergistic effects of ultraviolet radiation (UVR) and low tide conditions on the embryonic mortality of two bubble-shell snail species that deposit gelatinous egg masses in intertidal mudflats: Haminoea zelandiae from New Zealand, and Haminoea vesicula from Washington, USA. Egg masses of both species were predominantly found in shallow pools at low tide, and a substantial proportion of both were found in sunny as well as shaded microhabitats. Both exposure to sun and desiccation led to increased embryonic mortality for naturally deposited egg masses of H. zelandiae compared to those that were shaded or submerged. For H. vesicula, although mortality was double for embryos within desiccated egg masses, there was no additional mortality due to sun exposure. In manipulative experiments, UVR and low tide conditions increased embryonic mortality for both species; however, H. zelandiae appeared to be more vulnerable to UVR, whereas H. vesicula was particularly vulnerable to desiccation. Simulated tidal pool conditions significantly increased mortality only for H. vesicula. These results suggest an important role of species-specific differences in vulnerability to different stressors, even for ecologically similar congeners; here, these differences may be related to development time or egg mass characteristics.

  6. Fasciola hepatica in snails collected from water-dropwort fields using PCR.

    Science.gov (United States)

    Kim, Hwang-Yong; Choi, In-Wook; Kim, Yeon-Rok; Quan, Juan-Hua; Ismail, Hassan Ahmed Hassan Ahmed; Cha, Guang-Ho; Hong, Sung-Jong; Lee, Young-Ha

    2014-12-01

    Fasciola hepatica is a trematode that causes zoonosis mainly in cattle and sheep and occasionally in humans. Fascioliasis has been reported in Korea; however, determining F. hepatica infection in snails has not been done recently. Thus, using PCR, we evaluated the prevalence of F. hepatica infection in snails at 4 large water-dropwort fields. Among 349 examined snails, F. hepatica-specific internal transcribed space 1 (ITS-1) and/or ITS-2 markers were detected in 12 snails and confirmed using sequence analysis. Morphologically, 213 of 349 collected snails were dextral shelled, which is the same aperture as the lymnaeid snail, the vectorial host for F. hepatica. Among the 12 F. hepatica-infected snails, 6 were known first intermediate hosts in Korea (Lymnaea viridis and L. ollula) and the remaining 6 (Lymnaea sp.) were potentially a new first intermediate host in Korea. It has been shown that the overall prevalence of the snails contaminated with F. hepatica in water-dropwort fields was 3.4%; however, the prevalence varied among the fields. This is the first study to estimate the prevalence of F. hepatica infection using the vectorial capacity of the snails in Korea.

  7. Lichen endozoochory by snails.

    Science.gov (United States)

    Boch, Steffen; Prati, Daniel; Werth, Silke; Rüetschi, Jörg; Fischer, Markus

    2011-04-13

    Endozoochory plays a prominent role for the dispersal of seed plants. However, for most other plant taxa it is not known whether this mode of dispersal occurs at all. Among those other taxa, lichens as symbiotic associations of algae and fungi are peculiar as their successful dispersal requires movement of propagules that leaves the symbiosis functional. However, the potential for endozoochorous dispersal of lichen fragments has been completely overlooked. We fed sterile thalli of two foliose lichen species (Lobaria pulmonaria and Physcia adscendens) differing in habitat and air-quality requirements to nine snail species common in temperate Europe. We demonstrated morphologically that L. pulmonaria regenerated from 29.0% of all 379 fecal pellets, whereas P. adscendens regenerated from 40.9% of all 433 fecal pellets, showing that lichen fragments survived gut passage of all snail species. Moreover, molecular analysis of regenerated lichens confirmed the species identity for a subset of samples. Regeneration rates were higher for the generalist lichen species P. adscendens than for the specialist lichen species L. pulmonaria. Furthermore, lichen regeneration rates varied among snail species with higher rates after gut passage of heavier snail species. We suggest that gastropods generally grazing on lichen communities are important, but so far completely overlooked, as vectors for lichen dispersal. This opens new ecological perspectives and questions the traditional view of an entirely antagonistic relationship between gastropods and lichens.

  8. [Epidemiological data on human distomatosis (Fasciola hepatica L.) in the Limousin region of France. The species of plants eaten and snail hosts].

    Science.gov (United States)

    Rondelaud, D

    1980-01-01

    These epidemiological studies concern 187 cases of human fasciolasis which occurred in the region of Limousin, France on a period of 24 years. Four species of plants have been eaten: Nasturtium officinale, Roripa silvestris, Taraxacum gr. officinale, Valerianella olitoria. These plants have been eaten during all months of the year, but with higher numbers in July-August and from November to February. The cases of human fasciolasis almost take place on all years, but their numbers are high in years showing a very important infestation of cattle by Fasciola hepatica. In 2/3 of cases, the plants come from stations situated out of cattle pastures. The water-cress almost comes from natural stations or from familial plantations. Five species of snails have been observed in these stations: Lymnaea glabra, L. palustris, L. peregra, L. stagnalis, L. truncatula. The young snails of these species experimentally have been observed. The significance of these results is discussed.

  9. Snails home

    Science.gov (United States)

    Dunstan, D. J.; Hodgson, D. J.

    2014-06-01

    Many gardeners and horticulturalists seek non-chemical methods to control populations of snails. It has frequently been reported that snails that are marked and removed from a garden are later found in the garden again. This phenomenon is often cited as evidence for a homing instinct. We report a systematic study of the snail population in a small suburban garden, in which large numbers of snails were marked and removed over a period of about 6 months. While many returned, inferring a homing instinct from this evidence requires statistical modelling. Monte Carlo techniques demonstrate that movements of snails are better explained by drift under the influence of a homing instinct than by random diffusion. Maximum likelihood techniques infer the existence of two groups of snails in the garden: members of a larger population that show little affinity to the garden itself, and core members of a local garden population that regularly return to their home if removed. The data are strongly suggestive of a homing instinct, but also reveal that snail-throwing can work as a pest management strategy.

  10. How did this snail get here? Several dispersal vectors inferred for an aquatic invasive species

    NARCIS (Netherlands)

    Van Leeuwen, C.H.A.; Huig, N.; Van der Velde, G.; Van Alen, T.; Wagemaker, C.A.M.; Sherman, C.D.H.; Klaassen, M.R.J.; Figuerola, J.

    2013-01-01

    How species reach and persist in isolated habitats remains an open question in many cases, especially for rapidly spreading invasive species. This is particularly true for temporary freshwater ponds, which can be remote and may dry out annually, but may still harbour high biodiversity. Persistence i

  11. How did this snail get here? Several dispersal vectors inferred for an aquatic invasive species

    NARCIS (Netherlands)

    Van Leeuwen, C.H.A.; Huig, N.; Van der Velde, G.; Van Alen, T.; Wagemaker, C.A.M.; Sherman, C.D.H.; Klaassen, M.R.J.; Figuerola, J.

    2013-01-01

    How species reach and persist in isolated habitats remains an open question in many cases, especially for rapidly spreading invasive species. This is particularly true for temporary freshwater ponds, which can be remote and may dry out annually, but may still harbour high biodiversity. Persistence

  12. A new species of hydrobiid snails (Mollusca, Gastropoda, Hydrobiidae from central Greece

    Directory of Open Access Journals (Sweden)

    Canella Radea

    2011-10-01

    Full Text Available A new minute valvatiform species belonging to the genus Daphniola Radoman 1973, Daphniola eptalophos sp. n., from mountain Parnassos, Greece is described. The new species has a transparent valvatiform-planispiral shell, wide and open umbilicus, grey-black pigmented soft body and head and a black penis with a small colorless outgrowth on the left side near its base. A comparative table of shell dimensions and a key to the species known for this endemic genus for Greece are provided.

  13. Feeding behavior of black carp Mylopharyngodon piceus (Pisces: Cyprinidae) on fry of other fish species and trematode transmitting snail species

    DEFF Research Database (Denmark)

    Hung, Nguyen Manh; The, Dang Tat; Stauffer, Jay R.

    2014-01-01

    Fish raised in aquaculture ponds may get infected with fishborne zoonotic trematodes (FZT) during the nursing stage. Freshwater snails serve as intermediate hosts for FZT and we wanted to explore the possibility of controlling snails by stocking nursery ponds with a few juvenile specimens...

  14. A new species of the operculate land snail genus Maizaniella from Liberia (Gastropoda, Caenogastropoda)

    NARCIS (Netherlands)

    Winter, de A.J.

    2009-01-01

    Maizaniella sapoensis spec. nov. from Liberia is described. The species is provisionally att ributed to the subgenus Spirulozania. It is by far the smallest known member of the genus, with an adult shell diameter of just over 2 mm.

  15. A malacological survey in the Manso Power Plant, State of Mato Grosso, Brazil: new records of freshwater snails, including transmitters of schistosomiasis and exotic species

    Directory of Open Access Journals (Sweden)

    Monica Ammon Fernandez

    2014-07-01

    Full Text Available Introduction Schistosomiasis is a parasitic disease of public health concern in Brazil, and the construction of hydroelectric dams, in addition to increasing permanent human settlement and tourism, has created conditions suitable for the establishment of mollusks that can transmit schistosomiasis. Such areas require a number of actions to prevent the establishment of schistosomiasis. This paper reports on a freshwater malacological survey carried out in the geographical area of the Manso Power Plant. Methods Mollusks were collected in 18 municipalities in the State of Mato Grosso between February 2002 and February 2004 (qualitative study and from April 2009 to February 2011 (quantitative study. Results Thirty-one species of mollusks were collected, including newly recorded species (Antillorbis nordestensis and Burnupia ingae. In addition, the geographic distributions of known species, including Biomphalaria straminea, a snail vector of Schistosoma mansoni, were expanded. A total of 4,507 specimens were collected in the APM Manso reservoir (Usina Hidrelétrica de Aproveitamento Múltiplo de Manso during the quantitative study, and Biomphalaria amazonica was found in six of the 10 localities analyzed. The Afroasiatic species Melanoides tuberculata, introduced after February 2009, was the dominant species (relative abundance 94.96%. Conclusions The study area is epidemiologically important due to the occurrence of B. straminea and B. amazonica, which are vectors of schistosomiasis, and M. tuberculata, a snail host of Centrocestus formosanus, which is responsible for centrocestiasis transmission. Observations of M. tuberculata and the exotic freshwater clams Corbicula fluminea and Corbicula largillierti raise concerns about biodiversity.

  16. Larval trematodes (Digenea of the great pond snail, Lymnaea stagnalis (L., (Gastropoda, Pulmonata in Central Europe: a survey of species and key to their identification

    Directory of Open Access Journals (Sweden)

    Faltýnková A.

    2007-03-01

    Full Text Available A survey of cercariae and metacercariae (Trematoda, Digenea from the great pond snail (Lymnaea stagnalis in Central Europe (Austria, Czech Republic, South-East Germany, Poland and Slovak Republic is presented, based on a study of 3,628 snails examined from 1998 to 2005. A total of 953 (26.3% L. stagnalis were infected with 24 trematode species comprising 19 species of cercariae and 11 species of metacercariae (six species occurred both as cercarie and metacercarie of eight families. The dominant cercariae were those of Opisthioglyphe ranae (159 hosts infected, Plagiorchis elegans (141 (both family Plagiorchiidae and Echinoparyphium aconiatum (153 (Echinostomatidae; 14 double infections were found. The most frequent metacercariae were those of Neoglyphe locellus (71 (Omphalometridae, E. aconiatum (66, Echinostoma sp. (59 and Moliniella anceps (48 (Echinostomatidae. In the previous studies carried out in Central Europe, a very similar spectrum of nine trematode families of 22 cercariae determined to species level and 43 types of cercariae reported under generic or provisional names, which can be in many cases conspecific with the previous taxa, were found. A simple key to identification of cercariae and metacercariae, together with their illustrations, is provided.

  17. Taxonomical study on a sample of land and freshwater snails from caves in central Brazil, with description of a new species

    Directory of Open Access Journals (Sweden)

    Rodrigo B. Salvador

    2017-02-01

    Full Text Available A sample of land and freshwater snails, mainly pulmonates, was recently collected in caves in Goiás and Bahia states, Brazil. Twenty-one species were found in the material. The following species are reported for the first time for Goiás state: Cecilioides consobrina (Ferussaciidae, Dysopeas muibum and Stenogyra octogyra (Subulinidae, Entodina jekylli and Prohappia besckei (Scolodontidae; also reported for the first time for Bahia state, Pupisoma dioscoricola (Valloniidae. A new species from Goiás is described herein: Gastrocopta sharae sp. n. (Gastrocoptidae. The new records and species addressed here constitute important findings, helping to fill distributional gaps and improving the knowledge of the local molluscan fauna, an essential step for future conservation efforts.

  18. Differences in the compatibility of infection between the liver flukes Fascioloides magna and Fasciola hepatica in a Colombian population of the snail Galba sp.

    Science.gov (United States)

    Dreyfuss, G; Correa, A C; Djuikwo-Teukeng, F F; Novobilský, A; Höglund, J; Pankrác, J; Kašný, M; Vignoles, P; Hurtrez-Boussès, S; Pointier, J P; Rondelaud, D

    2015-11-01

    Experimental infections of Galba sp. (origin, Colombia) with allopatric isolates of Fasciola hepatica from France or Fascioloides magna from the Czech Republic were carried out during five successive snail generations to determine if this lymnaeid might sustain complete larval development of either parasite. In snails exposed to F. hepatica, 7 of 400 snails harboured several rediae and only two snails contained a small number of free cercariae on day 50 post-exposure. In contrast, the intensity of F. magna infection in Galba sp. progressively increased from the F1 to F5 generations. Spontaneous cercarial shedding of F. magna occurred in 7 of 100 Galba sp. belonging to the F5 generation and the number of shed cercariae did not differ significantly from that noted in control Galba truncatula of French origin. Galba sp. from Colombia can be added to the list of potential intermediate hosts for F. magna.

  19. Distribution of Lymnaeidae (Mollusca: Pulmonata), intermediate snail hosts of Fasciola hepatica in Venezuela.

    Science.gov (United States)

    Pointier, J P; Noya, O; Alarcón de Noya, B; Théron, A

    2009-08-01

    An extensive malacological survey was carried out between 2005-2009 in order to clarify the exact number of lymnaeid species which may be intermediate hosts of Fasciola hepatica in Venezuela. Four species were discovered during this survey, including two local species: Lymnaea cubensis and Lymnaea cousini and two exotic species: Lymnaea truncatula and Lymnaea columella. The most common local species was L. cubensis which was found at 16 out of the 298 sampling sites. This species has a large distribution area throughout the Northern part of Venezuela and was encountered from sea level to an altitude of 1,802 m in state of Trujillo. The second local species L. cousini was collected at only two sites of the Andean Region at altitudes of 3,550 m and 4,040 m, respectively. The European L. truncatula was found at 24 sites all located in the states of Mérida and Táchira at an altitude varying between 1,540-4,000 m. The respective distribution areas of L. cubensis and L. truncatula do not appear to overlap, but more detailed malacological surveys are needed. The fourth lymnaeid species, L. columella was collected in a canal from Mérida at an altitude of 1,929 m and in an irrigation canal from the state of Guárico, at an altitude of 63 m. The role of these four lymnaeid species in the transmission of fascioliasis in Venezuela is discussed.

  20. Distribution of Lymnaeidae (Mollusca: Pulmonata, intermediate snail hosts of Fasciola hepatica in Venezuela

    Directory of Open Access Journals (Sweden)

    JP Pointier

    2009-08-01

    Full Text Available An extensive malacological survey was carried out between 2005-2009 in order to clarify the exact number of lymnaeid species which may be intermediate hosts of Fasciola hepatica in Venezuela. Four species were discovered during this survey, including two local species: Lymnaea cubensis and Lymnaea cousini and two exotic species: Lymnaea truncatula and Lymnaea columella. The most common local species was L. cubensis which was found at 16 out of the 298 sampling sites. This species has a large distribution area throughout the Northern part of Venezuela and was encountered from sea level to an altitude of 1,802 m in state of Trujillo. The second local species L. cousini was collected at only two sites of the Andean Region at altitudes of 3,550 m and 4,040 m, respectively. The European L. truncatula was found at 24 sites all located in the states of Mérida and Táchira at an altitude varying between 1,540-4,000 m. The respective distribution areas of L. cubensis and L. truncatula do not appear to overlap, but more detailed malacological surveys are needed. The fourth lymnaeid species, L. columella was collected in a canal from Mérida at an altitude of 1,929 m and in an irrigation canal from the state of Guárico, at an altitude of 63 m. The role of these four lymnaeid species in the transmission of fascioliasis in Venezuela is discussed.

  1. Edible Snails (Terrestrial) of Turkey

    OpenAIRE

    YILDIRIM, M. Zeki

    2004-01-01

    Edible species and their distribution in Turkey were studied. The absence of Helix pomatia, a species reported to occur in Turkey in resources in various disciplines, is mentioned, while 7 species of edible snails determined (Theba pisana, Eobania vermiculata, Cryptomphalus aspersus, Cantareus apertus, Helix asemnis, Helix cincta and Helix lucorum) are described in detail by means of morphology, distribution, systematical positions, and a key to the species is given. Additionally, problems ab...

  2. Aptitude of Lymnaea palustris and L. stagnalis to Fasciola hepatica larval development through the infection of several successive generations of 4-mm-high snails.

    Science.gov (United States)

    Vignoles, P; Rondelaud, D; Dreyfuss, G

    2016-06-01

    Bimiracidial infections of Lymnaea palustris and Lymnaea stagnalis (shell height at exposure, 4 mm) with Fasciola hepatica were carried out during six successive snail generations to determine if prevalence and intensity of snail infection increased over time through descendants issuing from eggs laid by parents already exposed to this digenean. Controls were constituted by a French population of Galba truncatula (a single generation) infected according to the same protocol. In a first experiment performed with the F1 to F5 generations of L. palustris, the prevalence and intensity of F. hepatica infection in snails progressively increased. Immature rediae and a few cercariae-containing rediae of the digenean were observed in L. stagnalis from the F3 generation, but no free cercaria was noted in the bodies of this lymnaeid from the F4 to F6 generations. In another experiment carried out with the F6 generation of L. palustris, the prevalence of F. hepatica infection and the number of shed cercariae were significantly lower in L. palustris than in G. truncatula. This mode of snail infection suggests an explanation for cases of human fasciolosis occurring in central France after the collection of wild watercress from beds where L. palustris was the sole lymnaeid.

  3. Calicophoron daubneyi and Fasciola hepatica: characteristics of natural and experimental co-infections of these digeneans in the snail Lymnaea glabra.

    Science.gov (United States)

    Vignoles, P; Titi, A; Mekroud, A; Rondelaud, D; Dreyfuss, G

    2017-01-01

    A retrospective study on different Lymnaea glabra samples collected from central France between 1993 and 2010 was carried out to determine the prevalence of natural co-infections with Calicophoron daubneyi and Fasciola hepatica, and to specify the composition of redial burdens. Experimental infections of L. glabra performed during the same period of time were also analysed to study metacercarial production of each digenean in co-infected snails. Controls were naturally or experimentally co-infected Galba truncatula. In natural co-infections, prevalence was 0.7% in L. glabra (186/25,128) and 0.4% in G. truncatula (137/31,345). Low redial burdens were found in these snails, with F. hepatica rediae significantly more numerous in L. glabra than in G. truncatula (7.5 per snail instead of 5.2). In contrast, the total numbers of C. daubneyi rediae in both lymnaeids were close to each other (4.3 and 3.0 rediae, respectively). In experimentally co-infected groups, prevalence was greater in G. truncatula than in the other lymnaeid (6.3% instead of 3.0%). Significantly shorter patent periods and lower metacercarial production for each digenean were noted in L. glabra than in G. truncatula. However, in both lymnaeids, the two types of cercariae were released during the same shedding waves and several peaks during the patent period were synchronous. In spite of a greater shell height for L. glabra, metacercarial production of both digeneans in co-infected snails was lower than that in G. truncatula, thus indicating a still incomplete adaptation between these French L. glabra and both parasites.

  4. Genetic Basis of Differential Heat Resistance between Two Species of Congeneric Freshwater Snails: Insights from Quantitative Proteomics and Base Substitution Rate Analysis.

    Science.gov (United States)

    Mu, Huawei; Sun, Jin; Fang, Ling; Luan, Tiangang; Williams, Gray A; Cheung, Siu Gin; Wong, Chris K C; Qiu, Jian-Wen

    2015-10-02

    We compared the heat tolerance, proteomic responses to heat stress, and adaptive sequence divergence in the invasive snail Pomacea canaliculata and its noninvasive congener Pomacea diffusa. The LT50 of P. canaliculata was significantly higher than that of P. diffusa. More than 3350 proteins were identified from the hepatopancreas of the snails exposed to acute and chronic thermal stress using iTRAQ-coupled mass spectrometry. Acute exposure (3 h exposure at 37 °C with 25 °C as control) resulted in similar numbers (27 in P. canaliculata and 23 in P. diffusa) of differentially expressed proteins in the two species. Chronic exposure (3 weeks of exposure at 35 °C with 25 °C as control) caused differential expression of more proteins (58 in P. canaliculata and 118 in P. diffusa), with many of them related to restoration of damaged molecules, ubiquitinating dysfunctional molecules, and utilization of energy reserves in both species; but only in P. diffusa was there a shift from carbohydrate to lipid catabolism. Analysis of orthologous genes encoding the differentially expressed proteins revealed two genes having clear evidence of positive selection (Ka/Ks > 1) and seven candidates for more detailed analysis of positive selection (Ka/Ks between 0.5 and 1). These nine genes are related to energy metabolism, cellular oxidative homeostasis, signaling, and binding processes. Overall, the proteomic and base substitution rate analyses indicate genetic basis of differential resistance to heat stress between the two species, and such differences could affect their further range expansion in a warming climate.

  5. Brachylaima ezohelicis sp. nov. (Trematoda: Brachylaimidae) found from the land snail Ezohelix gainesi, with a note of an unidentified Brachylaima species in Hokkaido, Japan.

    Science.gov (United States)

    Nakao, Minoru; Waki, Tsukasa; Sasaki, Mizuki; Anders, Jason L; Koga, Daisuke; Asakawa, Mitsuhiko

    2017-06-01

    In the Japanese Archipelago, Ezohelix gainesi, a member of bradybaenid land snails, is endemic mainly to the island of Hokkaido. During July to August of 2016, a survey to detect trematode infections from E. gainesi was carried out at a forest city park in Asahikawa, Hokkaido. Systemic infections of the snails with sporocysts containing short-tailed cercariae were found in 5.3% of 94 individuals examined. Furthermore, most of them (90.4%) harbored non-encysted metacercariae within their kidneys. A DNA sequence identification revealed that both of the sporocyst and the metacercaria belong to an unknown species of the family Brachylaimidae. The metacercariae showed a genetic diversity with 6 haplotypes of mitochondrial DNA (mtDNA) even in the limited sampling area. A definitive host of the unknown species could not be determined, although 34 field mice (Apodemus speciosus) and 21 voles (Myodes rufocanus) from the city park were examined for intestinal parasites. To examine the adult stage, the metacercariae were perorally administrated to mice, together with anti-inflammatory treatment with methylprednisolone. Fully matured adult worms were recovered from the intestinal ileum 8 and 14days postinfection. The gravid adults showed typical features of the genus Brachylaima. A morphological and biogeographical evaluation prompted us to propose Brachylaima ezohelicis sp. nov. for the parasite from E. gainesi. The autochthony of the first intermediate host and the spatial heterogeneity of mtDNA suggest that the new species found in the city park is not a recently expanded population of immigrant origin. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Modeling freshwater snail habitat suitability and areas of potential snail-borne disease transmission in Uganda

    Directory of Open Access Journals (Sweden)

    A.S. Stensgaard

    2006-11-01

    Full Text Available Geographic information system (GIS-based modeling of an intermediate host snail species’ environmental requirements using known occurrence records can provide estimates of its spatial distribution. When other data are lacking, this can be used as a rough spatial prediction of potential snail-borne disease transmission areas. Furthermore, knowledge of abiotic factors affecting intra-molluscan parasitic development can be used to make “masks” based on remotely sensed climatic data, and these can in turn be used to refine these predictions. We used data from a recent freshwater snail survey from Uganda, environmental data and the genetic algorithm for rule-set prediction (GARP to map the potential distribution of snail species known to act as intermediate hosts of several human and animal parasites. The results suggest that large areas of Uganda are suitable habitats for many of these snail species, indicating a large potential for disease transmission. The lack of parasitological data still makes it difficult to determine the magnitude of actual disease transmission, but the predicted snail distributions might be used as indicators of potential present and future risk areas. Some of the predicted snail distribution maps were furthermore combined with temperature masks delineating suitable temperature regimes of the parasites they host. This revealed the coinciding suitable areas for snail and parasite, but also areas suitable for host snails, but apparently not for the parasites. Assuming that the developed models correctly reflect areas suitable for transmission, the applied approach could prove useful for targeting control interventions.

  7. Complete mitochondrial genome of the giant African snail, Achatina fulica (Mollusca: Achatinidae): a novel location of putative control regions (CR) in the mitogenome within Pulmonate species.

    Science.gov (United States)

    He, Zhang-Ping; Dai, Xia-Bin; Zhang, Shuai; Zhi, Ting-Ting; Lun, Zhao-Rong; Wu, Zhong-Dao; Yang, Ting-Bao

    2016-01-01

    The whole sequence (15,057 bp) of the mitochondrial DNA (mtDNA) of the terrestrial snail Achatina fulica (order Stylommatophora) was determined. The mitogenome, as the typical metazoan mtDNA, contains 13 protein-coding genes (PCG), 2 ribosomal RNA genes (rRNA) and 22 transfer RNA genes (tRNA). The tRNA genes include two trnS without standard secondary structure. Interestingly, among the known mitogenomes of Pulmonata species, we firstly characterized an unassigned lengthy sequence (551 bp) between the cox1 and the trnV which may be the CR for the sake of its AT bases usage bias (65.70%) and potential hairpin structure.

  8. DNA sequence characterisation and phylogeography of Lymnaea cousini and related species, vectors of fascioliasis in northern Andean countries, with description of L. meridensis n. sp. (Gastropoda: Lymnaeidae

    Directory of Open Access Journals (Sweden)

    Bargues M Dolores

    2011-07-01

    Full Text Available Abstract Background Livestock fascioliasis is a problem throughout Ecuador, Colombia and Venezuela, mainly in Andean areas where the disease also appears to affect humans. Transmission patterns and epidemiological scenarios of liver fluke infection have shown to differ according to the lymnaeid vector snail species involved. These Andean countries present the vectors Lymnaea cousini, L. bogotensis and L. ubaquensis, unknown in the rest of Latin America. An exhaustive combined haplotype study of these species is performed by means of DNA sequencing of the nuclear ribosomal 18S RNA gene, ITS-2 and ITS-1, and mitochondrial DNA cox1 gene. Results The conserved 5.8S rDNA sequence corroborated that no pseudogenes are involved in the numerous non-microsatellite/minisatellite-related indels appearing between the ITS-2 and ITS-1 sequences when comparing different L. cousini - L. bogotensis populations. Sequence analyses and phylogenetic reconstruction methods including other lymnaeid vector species show that (i L. bogotensis is a synonym of L. cousini, (ii L. ubaquensis is a synonym of Pseudosuccinea columella, and (iii populations of L. cousini hitherto known from Venezuelan highlands indeed belong to a new species for which the name L. meridensis n. sp. is proposed. This new species is described and a complete phenotypic differentiation provided. Conclusions ITS-2, ITS-1 and cox1 prove to be good markers for specimen classification and haplotype characterisation of these morphologically similar lymnaeids in endemic areas. Analysis of the 18S gene and phylogenetic reconstructions indicate that L. cousini and L. meridensis n. sp. cluster in an evolutionary line different from the one of P. columella, despite their external resemblance. This suggests an evolutionary phenotypic convergence related to similar environments and which has given rise to frequent specimen misclassification. Body size and phylogenetic relationships of L. meridensis n. sp. with

  9. Modeling freshwater snail habitat suitability and areas of potential snail-borne disease transmission in Uganda

    DEFF Research Database (Denmark)

    Stensgaard, Anna-Sofie; Jørgensen, Aslak; Kabatereine, N B

    2006-01-01

    Geographic information system (GIS-based modeling of an intermediate host snail species environmental requirements using known occurrence records can provide estimates of its spatial distribution. When other data are lacking, this can be used as a rough spatial prediction of potential snail......-borne disease transmission areas. Furthermore, knowledge of abiotic factors affecting intra-molluscan parasitic development can be used to make "masks" based on remotely sensed climatic data, and these can in turn be used to refine these predictions. We used data from a recent freshwater snail survey from...... Uganda, environmental data and the genetic algorithm for rule-set prediction (GARP) to map the potential distribution of snail species known to act as intermediate hosts of several human and animal parasites. The results suggest that large areas of Uganda are suitable habitats for many of these snail...

  10. Sampling designs for contaminant temporal trend analyses using sedentary species exemplified by the snails Bellamya aeruginosa and Viviparus viviparus.

    Science.gov (United States)

    Yin, Ge; Danielsson, Sara; Dahlberg, Anna-Karin; Zhou, Yihui; Qiu, Yanling; Nyberg, Elisabeth; Bignert, Anders

    2017-10-01

    Environmental monitoring typically assumes samples and sampling activities to be representative of the population being studied. Given a limited budget, an appropriate sampling strategy is essential to support detecting temporal trends of contaminants. In the present study, based on real chemical analysis data on polybrominated diphenyl ethers in snails collected from five subsites in Tianmu Lake, computer simulation is performed to evaluate three sampling strategies by the estimation of required sample size, to reach a detection of an annual change of 5% with a statistical power of 80% and 90% with a significant level of 5%. The results showed that sampling from an arbitrarily selected sampling spot is the worst strategy, requiring much more individual analyses to achieve the above mentioned criteria compared with the other two approaches. A fixed sampling site requires the lowest sample size but may not be representative for the intended study object e.g. a lake and is also sensitive to changes of that particular sampling site. In contrast, sampling at multiple sites along the shore each year, and using pooled samples when the cost to collect and prepare individual specimens are much lower than the cost for chemical analysis, would be the most robust and cost efficient strategy in the long run. Using statistical power as criterion, the results demonstrated quantitatively the consequences of various sampling strategies, and could guide users with respect of required sample sizes depending on sampling design for long term monitoring programs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Snails and trematode infection after Indian Ocean tsunami in Phang-Nga Province, southern Thailand.

    Science.gov (United States)

    Sri-Aroon, Pusadee; Chusongsang, Phiraphol; Chusongsang, Yupa; Pornpimol, Surinthwong; Butraporn, Piyarat; Lohachit, Chantima

    2010-01-01

    The tsunami and non-tsunami affected areas of Takua Pa District, Phang-Nga Province were investigated for fresh- and brackish-water snails that transmit human parasitic diseases during 2006 and 2007. Among 46 snail species found, 17 species of 8 families were freshwater snails, 28 species of another 7 families were brackish-water snails, and 1 species was a land snail. Of these species, 11 freshwater snails, 4 brackish-water snails and 1 land snail were of medical importance. The fresh-water snails were Pomacea canaliculata, Pila angelica, P. gracilis, P. polita, Filopaludina (S.) martensi, F. (F.) s. polygramma, Melanoides tuberculata, Indoplanorbis exuxtus, Radix rubiginosa, Helicorbis umbilicalis, Gyraulus convexiusculus. Four brackish-water snails were Cerithidea cingulata, C. djadjarensis, C. alata, Sermyla riqueti and Achatina fulica was the land snail. I. exutus, M. tuberculata and F. (F.) s. polygramma harbored Xiphidio, Microcercus, Furocercus, Echinostome cercariae, and cercaria without eyespots or tail with hair. Three species of brackish-water snails, Cerithidia cingulata, C. djadjariensis, and C. alata presented with 6 types of trematode cercariae and rediae. Knowledge of medically important snails and their parasitic diseases, and prevention were given to Takua Pa people by poster, pamphlets and broadcasting through community radio.

  12. Snail: More than EMT.

    Science.gov (United States)

    Wu, Yadi; Zhou, Binhua P

    2010-01-01

    Snail has moved into the fast lane of development and cancer biology with the epithelial-mesenchymal transition (EMT) emerging as one of the hottest topics in medical science within the past few years. Snail not only acts primarily as a key inducer of EMT but also plays an important role in cell survival, immune regulation and stem cell biology. This review focuses on the regulation of Snail and discusses the EMT-dependent and -independent functions of Snail in development and disease. Understanding the regulation and functional roles of Snail will shed new light on the mechanism of tumor progression and the development of novel cancer therapies.

  13. The effects of the herbicide atrazine on freshwater snails.

    Science.gov (United States)

    Gustafson, Kyle D; Belden, Jason B; Bolek, Matthew G

    2015-07-01

    Atrazine has been shown to affect freshwater snails from the subcellular to community level. However, most studies have used different snail species, methods, endpoints, and atrazine exposure concentrations, resulting in some conflicting results and limiting our understanding. The goal of this study was to address these concerns by (1) investigating the acute and chronic effects of atrazine on four species of freshwater snails (Biomphalaria glabrata, Helisoma trivolvis, Physa acuta, and Stagnicola elodes) using the same methods, endpoints, and concentrations, and (2) summarizing the current literature pertaining to the effects of atrazine on freshwater snails. We conducted a 48 h acute toxicity test with an atrazine concentration higher than what typically occurs in aquatic environments (1000 µg/L). Additionally, we exposed snails to environmentally relevant atrazine concentrations (0, 0.3, 3, and 30 µg/L) for 28 days and assessed snail survival, growth, and reproduction. We also summarized all known literature pertaining to atrazine effects on freshwater snails. The literature summary suggests snails are often affected by environmentally relevant atrazine concentrations at the subcellular and cellular levels. These effects are typically not transitive to effects on survival, growth, or reproduction at the same concentrations. Our acute exposures corroborate the general trend of no direct effect on snail populations as atrazine did not directly affect the survival of any of the four snail species. Similarly, environmentally relevant concentrations did not significantly affect the survival, growth, or reproduction of any snail species. These results indicate that, in the absence of other possible stressors, the direct effects of environmentally relevant atrazine concentrations may not be realized at the snail population level.

  14. Effects of organic contaminants in reactive oxygen species, protein carbonylation and DNA damage on digestive gland and haemolymph of land snails.

    Science.gov (United States)

    Itziou, A; Kaloyianni, M; Dimitriadis, V K

    2011-10-01

    The present study focused on early responses of land snails Eobania vermiculata to organic environmental contaminants, by investigating the use of a newly-established method for the measurement of protein carbonylation as a new biomarker of terrestrial pollution, as well as by measuring the ROS production and the DNA damage. Land snails were exposed to different concentrations of chlorpyrifos, parathion-methyl or PAHs in vivo or in vitro in the laboratory. The susceptibility of exposed snails was increased in relation to oxidative stress induced by contaminants tested. A statistically significant increase in ROS production, protein carbonylation and DNA damage was revealed in the snails treated with pollutants, compared to the untreated ones. The results indicated the effectiveness of measuring ROS production and DNA damage and reinforce the application of the present ELISA method in organic terrestrial pollution biomonitoring studies.

  15. Factors and processes shaping the population structure and distribution of genetic variation across the species range of the freshwater snail radix balthica (Pulmonata, Basommatophora

    Directory of Open Access Journals (Sweden)

    Feldmeyer Barbara

    2011-05-01

    Full Text Available Abstract Background Factors and processes shaping the population structure and spatial distribution of genetic diversity across a species' distribution range are important in determining the range limits. We comprehensively analysed the influence of recurrent and historic factors and processes on the population genetic structure, mating system and the distribution of genetic variability of the pulmonate freshwater snail Radix balthica. This analysis was based on microsatellite variation and mitochondrial haplotypes using Generalised Linear Statistical Modelling in a Model Selection framework. Results Populations of R. balthica were found throughout North-Western Europe with range margins marked either by dispersal barriers or the presence of other Radix taxa. Overall, the population structure was characterised by distance independent passive dispersal mainly along a Southwest-Northeast axis, the absence of isolation-by-distance together with rather isolated and genetically depauperated populations compared to the variation present in the entire species due to strong local drift. A recent, climate driven range expansion explained most of the variance in genetic variation, reducing at least temporarily the genetic variability in this area. Other factors such as geographic marginality and dispersal barriers play only a minor role. Conclusions To our knowledge, such a population structure has rarely been reported before. It might nevertheless be typical for passively dispersed, patchily distributed taxa (e.g. freshwater invertebrates. The strong local drift implied in such a structure is expected to erode genetic variation at both neutral and coding loci and thus probably diminish evolutionary potential. This study shows that the analysis of multiple factors is crucial for the inference of the processes shaping the distribution of genetic variation throughout species ranges.

  16. Freshwater snail consumption and angiostrongyliasis in Malaya.

    Science.gov (United States)

    Liat, L B; Fong, Y L; Krishnansamy, M; Ramachandran, P; Mansor, S

    1978-06-01

    A survey of the freshwater snails, Pila scutata and Bellamyia ingallsiana, as food consumed by the local population was carried out in Peninsular Malaysia. Of these two species the first is preferred; the sizes favoured are between 25--40 mm. Pila snails were found to be consumed by the three communities, viz. Malay, Chinese and Indian, in different ways. The various methods of preparing the snails for consumption are described. P. scutata is an intermediate host of the rat-lung worm, Angiostrongylus malaysiensis. As this worm presumably is the causative agent of human eosinophilic meningoencephalitis, the eating habits of the three races in consuming the snail in relation to the epidemiology of the disease was also discussed.

  17. A new species of snail-case caddisflies (Trichoptera: Helicopsychidae) and new records of caddisflies from Chapada Diamantina, Bahia, Brazil.

    Science.gov (United States)

    Souza, Raquel Lima DE; Gomes, Victor; Calor, Adolfo R

    2017-02-03

    A new species of Helicopsyche subgenus Feropsyche from Chapada Diamantina is diagnosed, described, and illustrated. Helicopsyche catoles n. sp. is easily distinguished from congeners by the following features: inferior appendages clavate, each bearing a posteroventral projection with 2-4 setae in lateral view, and tergum X with a notched apex and a short setal row along its length in dorsal view. Additionally, new records from Chapada Diamantina, Bahia, Brazil, are presented. A total of 31 species, including the new species, are recorded, belonging to 14 genera and 8 families. Two of these species constitute new records to Brazil (Helicopsyche (Feropsyche) succincta and Marilia misionensis) and another 10 of these species represent new records for Bahia [Chimarra (Curgia) hyoeides, Macronema hageni, M. partitum, Polyplectropus tragularius, Smicridea coronata, S. helenae, S. iguazu, S. jundiai, S. radula and Marilia major].

  18. Snail: More than EMT

    OpenAIRE

    Wu, Yadi; Zhou, Binhua P.

    2010-01-01

    Snail has moved into the fast lane of development and cancer biology with the epithelial-mesenchymal transition (EMT) emerging as one of the hottest topics in medical science within the past few years. Snail not only acts primarily as a key inducer of EMT but also plays an important role in cell survival, immune regulation and stem cell biology. This review focuses on the regulation of Snail and discusses the EMT-dependent and -independent functions of Snail in development and disease. Unders...

  19. Fecundity of the Chinese mystery snail in a Nebraska reservoir

    Science.gov (United States)

    Stephen, Bruce J.; Allen, Craig R.; Chaine, Noelle M.; Fricke, Kent A.; Haak, Danielle M.; Hellman, Michelle L.; Kill, Robert A.; Nemec, Kristine T.; Pope, Kevin L.; Smeenk, Nicholas A.; Uden, Daniel R.; Unstad, Kody M.; VanderHam, Ashley E.; Wong, Alec

    2013-01-01

    The Chinese mystery snail (Bellamya chinensis) is a non-indigenous, invasive species in freshwater ecosystems of North America. We provide fecundity estimates for a population of these snails in a Nebraska reservoir. We dissected 70 snails, of which 29 were females. Nearly all female snails contained developing young, with an average of 25 young per female. Annual fecundity was estimated at between 27.2 and 33.3 young per female per year. Based on an estimated adult population and the calculated fecundity, the annual production for this reservoir was between 2.2 and 3.7 million young.

  20. 76 FR 31866 - Endangered and Threatened Wildlife and Plants; Reclassification of the Tulotoma Snail From...

    Science.gov (United States)

    2011-06-02

    ...; Reclassification of the Tulotoma Snail From Endangered to Threatened AGENCY: Fish and Wildlife Service, Interior... snail (Tulotoma magnifica) from endangered to threatened, under the authority of the Endangered Species... this snail. DATES: This final rule is effective on July 5, 2011. ADDRESSES: This final rule...

  1. The faucet snail (Bithynia tentaculata) invades the St. Louis River Estuary

    Science.gov (United States)

    The European-origin faucet snail (Bithynia tentaculata) now numbers among the aquatic invasive species present in the St. Louis River Estuary. This snail has been in the lower Great Lakes since the early 20th century but is new to the Lake Superior basin. We found faucet snails...

  2. Environmental risk assessment for invasive alien species: A case study of apple snails affecting ecosystem services in Europe

    NARCIS (Netherlands)

    Gilioli, Gianni; Schrader, Gritta; Carlsson, Nils; van Donk, Ellen; van Leeuwen, Casper H.A.; Martín, Pablo R.; Pasquali, Sara; Vilà, Montserrat; Vos, Sybren

    Abstract The assessment of the risk posed by invasive alien species (IAS) to the environment is a component of increasing importance for Pest Risk Analysis. Standardized and comprehensive procedures to assess their impacts on ecosystem services have been developed only recently. The invasive apple

  3. The mitochondrial genome of the venomous cone snail Conus consors.

    Directory of Open Access Journals (Sweden)

    Age Brauer

    Full Text Available Cone snails are venomous predatory marine neogastropods that belong to the species-rich superfamily of the Conoidea. So far, the mitochondrial genomes of two cone snail species (Conus textile and Conus borgesi have been described, and these feed on snails and worms, respectively. Here, we report the mitochondrial genome sequence of the fish-hunting cone snail Conus consors and describe a novel putative control region (CR which seems to be absent in the mitochondrial DNA (mtDNA of other cone snail species. This possible CR spans about 700 base pairs (bp and is located between the genes encoding the transfer RNA for phenylalanine (tRNA-Phe, trnF and cytochrome c oxidase subunit III (cox3. The novel putative CR contains several sequence motifs that suggest a role in mitochondrial replication and transcription.

  4. Non-native molluscan colonizers on deliberately placed shipwrecks in the Florida Keys, with description of a new species of potentially invasive worm-snail (Gastropoda: Vermetidae)

    Science.gov (United States)

    Granados-Cifuentes, Camila; Rawlings, Timothy A.; Sierwald, Petra; Collins, Timothy M.

    2017-01-01

    Artificial reefs created by deliberately sinking ships off the coast of the Florida Keys island chain are providing new habitat for marine invertebrates. This newly developing fouling community includes the previously reported invasive orange tube coral Tubastraea coccinea and the non-native giant foam oyster Hyotissa hyotis. New SCUBA-based surveys involving five shipwrecks spanning the upper, middle, and lower Florida Keys, show T. coccinea now also established in the lower Keys and H. hyotis likewise extending to new sites. Two additional mollusks found on the artificial reefs, the amathinid gastropod Cyclothyca pacei and gryphaeid oyster Hyotissa mcgintyi, the latter also common in the natural reef areas, are discussed as potentially non-native. A new species of sessile, suspension-feeding, worm-snail, Thylacodes vandyensis Bieler, Rawlings & Collins n. sp. (Vermetidae), is described from the wreck of the USNS Vandenberg off Key West and discussed as potentially invasive. This new species is compared morphologically and by DNA barcode markers to other known members of the genus, and may be a recent arrival from the Pacific Ocean. Thylacodes vandyensis is polychromatic, with individuals varying in both overall head-foot coloration and mantle margin color pattern. Females brood stalked egg capsules attached to their shell within the confines of their mantle cavity, and give rise to crawl-away juveniles. Such direct-developing species have the demonstrated capacity for colonizing habitats isolated far from their native ranges and establishing rapidly growing founder populations. Vermetid gastropods are common components of the marine fouling community in warm temperate and tropical waters and, as such, have been tagged as potentially invasive or with a high potential to be invasive in the Pacific Ocean. As vermetids can influence coral growth/composition in the Pacific and have been reported serving as intermediate hosts for blood flukes of loggerhead turtles

  5. The Classroom Animal: Snails.

    Science.gov (United States)

    Kramer, David S.

    1985-01-01

    Points out that snails are interesting and easily-managed classroom animals. One advantage of this animal is that it requires no special attention over weekends or holidays. Background information, anatomy, reproduction, and feeding are discussed, along with suggestions for housing aquatic and/or land snails. (DH)

  6. Short read Illumina data for the de novo assembly of a non-model snail species transcriptome (Radix balthica, Basommatophora, Pulmonata, and a comparison of assembler performance

    Directory of Open Access Journals (Sweden)

    Rotter Björn

    2011-06-01

    Full Text Available Abstract Background Until recently, read lengths on the Solexa/Illumina system were too short to reliably assemble transcriptomes without a reference sequence, especially for non-model organisms. However, with read lengths up to 100 nucleotides available in the current version, an assembly without reference genome should be possible. For this study we created an EST data set for the common pond snail Radix balthica by Illumina sequencing of a normalized transcriptome. Performance of three different short read assemblers was compared with respect to: the number of contigs, their length, depth of coverage, their quality in various BLAST searches and the alignment to mitochondrial genes. Results A single sequencing run of a normalized RNA pool resulted in 16,923,850 paired end reads with median read length of 61 bases. The assemblies generated by VELVET, OASES, and SeqMan NGEN differed in the total number of contigs, contig length, the number and quality of gene hits obtained by BLAST searches against various databases, and contig performance in the mt genome comparison. While VELVET produced the highest overall number of contigs, a large fraction of these were of small size (BLAST searches and the mt genome alignment. The best overall contig performance resulted from the NGEN assembly. It produced the second largest number of contigs, which on average were comparable to the OASES contigs but gave the highest number of gene hits in two out of four BLAST searches against different reference databases. A subsequent meta-assembly of the four contig sets resulted in larger contigs, less redundancy and a higher number of BLAST hits. Conclusion Our results document the first de novo transcriptome assembly of a non-model species using Illumina sequencing data. We show that de novo transcriptome assembly using this approach yields results useful for downstream applications, in particular if a meta-assembly of contig sets is used to increase contig quality

  7. Conceptual shifts in animal systematics as reflected in the taxonomic history of a common aquatic snail species (Lymnaea stagnalis

    Directory of Open Access Journals (Sweden)

    Maxim V. Vinarski

    2015-07-01

    Full Text Available Lymnaea stagnalis (L., 1758 is among the most widespread and well-studied species of freshwater Mollusca of the northern hemisphere. It is also notoriously known for its huge conchological variability. The history of scientific exploration of this species may be traced back to the end of the 16th century (Ulisse Aldrovandi in Renaissance Italy and, thus, L. stagnalis has been chosen as a proper model taxon to demonstrate how changes in theoretical foundations and methodology of animal taxonomy have been reflected in the practice of classification of a particular taxon, especially on the intraspecific level. In this paper, I depict the long story of recognition of L. stagnalis by naturalists and biologists since the 16th century up to the present day. It is shown that different taxonomic philosophies (essentialism, population thinking, tree thinking led to different views on the species’ internal structure and its systematic position itself. The problem of how to deal with intraspecific variability in the taxonomic arrangement of L. stagnalis has been a central problem that made systematists change their opinion following conceptual shifts in taxonomic theory.

  8. Celss nutrition system utilizing snails

    Science.gov (United States)

    Midorikawa, Y.; Fujii, T.; Ohira, A.; Nitta, K.

    At the 40th IAF Congress in Malaga, a nutrition system for a lunar base CELSS was presented. A lunar base with a total of eight crew members was envisaged. In this paper, four species of plants—rice, soybean, lettuce and strawberry—were introduced to the system. These plants were sufficient to satisfy fundamental nutritional needs of the crew members. The supply of nutrition from plants and the human nutritional requirements could almost be balanced. Our study revealed that the necessary plant cultivation area per crew member would be nearly 40 m 3 in the lunar base. The sources of nutrition considered in the study were energy, sugar, fat, amino acids, inorganic salt and vitamins; however, calcium, vitamin B 2, vitamin A and sodium were found to be lacking. Therefore, a subsystem to supply these elements is of considerable value. In this paper, we report on a study for breeding snails and utilizing meat as food. Nutrients supplied from snails are shown to compensate for the abovementioned lacking elements. We evaluate the snail breeder and the associated food supply system as a subsystem of closed ecological life support system.

  9. Habitat preferences of coral-associated wentletrap snails (Gastropoda: Epitoniidae)

    NARCIS (Netherlands)

    Gittenberger, A.; Hoeksema, B.W.

    2013-01-01

    Examination of about 60,000 scleractinian corals of the families Dendrophylliidae, Euphylliidae and Fungiidae for the presence of associated wentletrap snails (Gastropoda: Epitoniidae) revealed various ectoparasitic life history strategies. Twenty Indo-Pacific wentletrap species were found, which we

  10. Whole genome analysis of a schistosomiasis-transmitting freshwater snail.

    Science.gov (United States)

    Adema, Coen M; Hillier, LaDeana W; Jones, Catherine S; Loker, Eric S; Knight, Matty; Minx, Patrick; Oliveira, Guilherme; Raghavan, Nithya; Shedlock, Andrew; do Amaral, Laurence Rodrigues; Arican-Goktas, Halime D; Assis, Juliana G; Baba, Elio Hideo; Baron, Olga L; Bayne, Christopher J; Bickham-Wright, Utibe; Biggar, Kyle K; Blouin, Michael; Bonning, Bryony C; Botka, Chris; Bridger, Joanna M; Buckley, Katherine M; Buddenborg, Sarah K; Lima Caldeira, Roberta; Carleton, Julia; Carvalho, Omar S; Castillo, Maria G; Chalmers, Iain W; Christensens, Mikkel; Clifton, Sandra; Cosseau, Celine; Coustau, Christine; Cripps, Richard M; Cuesta-Astroz, Yesid; Cummins, Scott F; di Stephano, Leon; Dinguirard, Nathalie; Duval, David; Emrich, Scott; Feschotte, Cédric; Feyereisen, Rene; FitzGerald, Peter; Fronick, Catrina; Fulton, Lucinda; Galinier, Richard; Gava, Sandra G; Geusz, Michael; Geyer, Kathrin K; Giraldo-Calderón, Gloria I; de Souza Gomes, Matheus; Gordy, Michelle A; Gourbal, Benjamin; Grunau, Christoph; Hanington, Patrick C; Hoffmann, Karl F; Hughes, Daniel; Humphries, Judith; Jackson, Daniel J; Jannotti-Passos, Liana K; de Jesus Jeremias, Wander; Jobling, Susan; Kamel, Bishoy; Kapusta, Aurélie; Kaur, Satwant; Koene, Joris M; Kohn, Andrea B; Lawson, Dan; Lawton, Scott P; Liang, Di; Limpanont, Yanin; Liu, Sijun; Lockyer, Anne E; Lovato, TyAnna L; Ludolf, Fernanda; Magrini, Vince; McManus, Donald P; Medina, Monica; Misra, Milind; Mitta, Guillaume; Mkoji, Gerald M; Montague, Michael J; Montelongo, Cesar; Moroz, Leonid L; Munoz-Torres, Monica C; Niazi, Umar; Noble, Leslie R; Oliveira, Francislon S; Pais, Fabiano S; Papenfuss, Anthony T; Peace, Rob; Pena, Janeth J; Pila, Emmanuel A; Quelais, Titouan; Raney, Brian J; Rast, Jonathan P; Rollinson, David; Rosse, Izinara C; Rotgans, Bronwyn; Routledge, Edwin J; Ryan, Kathryn M; Scholte, Larissa L S; Storey, Kenneth B; Swain, Martin; Tennessen, Jacob A; Tomlinson, Chad; Trujillo, Damian L; Volpi, Emanuela V; Walker, Anthony J; Wang, Tianfang; Wannaporn, Ittiprasert; Warren, Wesley C; Wu, Xiao-Jun; Yoshino, Timothy P; Yusuf, Mohammed; Zhang, Si-Ming; Zhao, Min; Wilson, Richard K

    2017-05-16

    Biomphalaria snails are instrumental in transmission of the human blood fluke Schistosoma mansoni. With the World Health Organization's goal to eliminate schistosomiasis as a global health problem by 2025, there is now renewed emphasis on snail control. Here, we characterize the genome of Biomphalaria glabrata, a lophotrochozoan protostome, and provide timely and important information on snail biology. We describe aspects of phero-perception, stress responses, immune function and regulation of gene expression that support the persistence of B. glabrata in the field and may define this species as a suitable snail host for S. mansoni. We identify several potential targets for developing novel control measures aimed at reducing snail-mediated transmission of schistosomiasis.

  11. Phenotypic plasticity of the introduced New Zealand mud snail, Potamopyrgus antipodarum, compared to sympatric native snails.

    Science.gov (United States)

    Levri, Edward P; Krist, Amy C; Bilka, Rachel; Dybdahl, Mark F

    2014-01-01

    Phenotypic plasticity is likely to be important in determining the invasive potential of a species, especially if invasive species show greater plasticity or tolerance compared to sympatric native species. Here in two separate experiments we compare reaction norms in response to two environmental variables of two clones of the New Zealand mud snail, Potamopyrgus antipodarum, isolated from the United States, (one invasive and one not yet invasive) with those of two species of native snails that are sympatric with the invader, Fossaria bulimoides group and Physella gyrina group. We placed juvenile snails in environments with high and low conductivity (300 and 800 mS) in one experiment, and raised them at two different temperatures (16 °C and 22 °C) in a second experiment. Growth rate and mortality were measured over the course of 8 weeks. Mortality rates were higher in the native snails compared to P. antipodarum across all treatments, and variation in conductivity influenced mortality. In both experiments, reaction norms did not vary significantly between species. There was little evidence that the success of the introduced species is a result of greater phenotypic plasticity to these variables compared to the sympatric native species.

  12. Phenotypic plasticity of the introduced New Zealand mud snail, Potamopyrgus antipodarum, compared to sympatric native snails.

    Directory of Open Access Journals (Sweden)

    Edward P Levri

    Full Text Available Phenotypic plasticity is likely to be important in determining the invasive potential of a species, especially if invasive species show greater plasticity or tolerance compared to sympatric native species. Here in two separate experiments we compare reaction norms in response to two environmental variables of two clones of the New Zealand mud snail, Potamopyrgus antipodarum, isolated from the United States, (one invasive and one not yet invasive with those of two species of native snails that are sympatric with the invader, Fossaria bulimoides group and Physella gyrina group. We placed juvenile snails in environments with high and low conductivity (300 and 800 mS in one experiment, and raised them at two different temperatures (16 °C and 22 °C in a second experiment. Growth rate and mortality were measured over the course of 8 weeks. Mortality rates were higher in the native snails compared to P. antipodarum across all treatments, and variation in conductivity influenced mortality. In both experiments, reaction norms did not vary significantly between species. There was little evidence that the success of the introduced species is a result of greater phenotypic plasticity to these variables compared to the sympatric native species.

  13. Revision of the dwarf cannibal snails (Nata s.l.) of southern Africa-Nata s.s. and Natella (Mollusca: Gastropoda: Rhytididae), with description of three new species.

    Science.gov (United States)

    Herbert, David G; Moussalli, Adnan

    2016-03-28

    This paper represents the second part of our revisionary studies on the rhytidid fauna of southern Africa. The species discussed belong to the taxon Nata s.l. in which we recognise two genus-level lineages, Nata s.s. and Natella with six (three new) and one species respectively. We update the species-level taxonomy extensively in the light of new molecular and morphological data, and provide a comprehensive revision of all species, including keys. Detailed comparative morphological observations are provided for the distal reproductive tract, pulmonary cavity, mantle edge, radula and suprapedal gland. In addition, we present a summary of biological and ecological data including information on habitat preferences, feeding, prey items and mating behaviour. Although the two genera are well circumscribed in terms of both internal anatomy and molecular data, shell morphology is highly conserved, and species discrimination using shell characters alone is difficult. We have discovered three undescribed species within Nata and there is evidence that further research of a phylogeographic nature may uncover additional cryptic diversity. The geographic distributions of the species are discussed in relation to regional vegetation patterns and, as with the larger cannibal snail radiation, the Albany Thicket Biome emerges as a focus of endemism. Observations on the conservation status of all species are provided.New species: Nata aequiplicata sp. nov., Nata erugata sp. nov. and Nata watsoni sp. nov. Revised status: Natalina caffrula Melvill & Ponsonby, 1898 is transferred to the genus Nata and thought to be a synonym of Nata dumeticola (Benson, 1851).

  14. Trematode communities in snails can indicate impact and recovery from hurricanes in a tropical coastal lagoon.

    Science.gov (United States)

    Aguirre-Macedo, María Leopoldina; Vidal-Martínez, Victor M; Lafferty, Kevin D

    2011-11-01

    In September 2002, Hurricane Isidore devastated the Yucatán Peninsula, Mexico. To understand its effects on the parasites of aquatic organisms, we analyzed long-term monthly population data of the horn snail Cerithidea pliculosa and its trematode communities in Celestún, Yucatán, Mexico before and after the hurricane (February 2001 to December 2009). Five trematode species occurred in the snail population: Mesostephanus appendiculatoides, Euhaplorchis californiensis, two species of the genus Renicola and one Heterophyidae gen. sp. Because these parasites use snails as first intermediate hosts, fishes as second intermediate hosts and birds as final hosts, their presence in snails depends on food webs. No snails were present at the sampled sites for 6 months after the hurricane. After snails recolonised the site, no trematodes were found in snails until 14 months after the hurricane. It took several years for snail and trematode populations to recover. Our results suggest that the increase in the occurrence of hurricanes predicted due to climate change can impact upon parasites with complex life cycles. However, both the snail populations and their parasite communities eventually reached numbers of individuals and species similar to those before the hurricane. Thus, the trematode parasites of snails can be useful indicators of coastal lagoon ecosystem degradation and recovery.

  15. Trematode communities in snails can indicate impact and recovery from hurricanes in a tropical coastal lagoon

    Science.gov (United States)

    Aguirre-Macedo, Maria Leopoldina; Vidal-Martinez, Victor M.; Lafferty, Kevin D.

    2011-01-01

    In September 2002, Hurricane Isidore devastated the Yucatán Peninsula, Mexico. To understand its effects on the parasites of aquatic organisms, we analyzed long-term monthly population data of the horn snail Cerithidea pliculosa and its trematode communities in Celestún, Yucatán, Mexico before and after the hurricane (February 2001 to December 2009). Five trematode species occurred in the snail population: Mesostephanus appendiculatoides, Euhaplorchis californiensis, two species of the genus Renicola and one Heterophyidae gen. sp. Because these parasites use snails as first intermediate hosts, fishes as second intermediate hosts and birds as final hosts, their presence in snails depends on food webs. No snails were present at the sampled sites for 6 months after the hurricane. After snails recolonised the site, no trematodes were found in snails until 14 months after the hurricane. It took several years for snail and trematode populations to recover. Our results suggest that the increase in the occurrence of hurricanes predicted due to climate change can impact upon parasites with complex life cycles. However, both the snail populations and their parasite communities eventually reached numbers of individuals and species similar to those before the hurricane. Thus, the trematode parasites of snails can be useful indicators of coastal lagoon ecosystem degradation and recovery.

  16. Austropeplea ollula (Pulmonata: Lymnaeidae): A new molluscan intermediate host of a human intestinal fluke, Echinostoma cinetorchis (Trematoda: Echinostomatidae) in Korea

    Science.gov (United States)

    Jung, Younghun; Park, Yun-Kyu; Hwang, Myung-Ki

    2001-01-01

    Three freshwater snail species of the family Lymnaeidae have been reported from Korea, Radix auricularia coreana, Austropeplea ollula and Fossaria truncatula. Out of 3 lymnaeid snail species, A. ollula was naturally infected with the Echinostoma cinetorchis cercariae (infection rate = 0.7%). In the experiments with the laboratory-bred snails, F. truncatula as well as A. ollula was also susceptible to the E. cinetorchis miracidia with infection rates of 25% and 40%, respectively. All of three lymnaeid snail species exposed to the E. cinetorchis cercariae were infected with the E. cinetorchis metacercariae. It is evident that A. ollula acts as the first molluscan intermediate host of E. cinetorchis in Korea, and F. truncatula may be a possible candidate for the first intermediate host of this intestinal fluke. Also, three lymnaeid snail species targeted were experimentally infected with E. cinetorchis metacercariae. PMID:11590915

  17. Molecular diversity of avian schistosomes in Danish freshwater snails

    DEFF Research Database (Denmark)

    Christiansen, Anne Ø.; Olsen, Annette; Buchmann, Kurt

    2016-01-01

    Avian schistosomes are widespread parasites of snails and waterfowl and may cause cercarial dermatitis (swimmer's itch) in humans, a disease that is frequently reported in European countries. These parasites are known to occur in Denmark, but here, we applied a new approach using molecular tools...... to identify the parasites at species level. In order to do that, 499 pulmonate freshwater snails (Radix sp., Lymnaea stagnalis, Stagnicola sp. and Planorbarius corneus) were sampled from 12 lakes, ponds, and marshes in the greater Copenhagen area. Avian schistosome cercariae were identified by microscopy...... and subjected to molecular investigation by sequencing and phylogenetic analysis of the 5.8S and ITS2 ribosomal DNA for species identification. Additionally, snail hosts belonging to the genus Radix were identified by sequencing and phylogenetic analysis of partial ITS2 ribosomal DNA. Three out of 499 snails...

  18. Effects of pollution on land snail abundance, size and diversity as resources for pied flycatcher, Ficedula hypoleuca.

    Science.gov (United States)

    Eeva, Tapio; Rainio, Kalle; Suominen, Otso

    2010-09-01

    Passerine birds need extra calcium during their breeding for developing egg shells and proper growth of nestling skeleton. Land snails are an important calcium source for many passerines and human-induced changes in snail populations may pose a severe problem for breeding birds. We studied from the bird's viewpoint how air pollution affects the shell mass, abundance and diversity of land snail communities along a pollution gradient of a copper smelter. We sampled remnant snail shells from the nests of an insectivorous passerine, the pied flycatcher, Ficedula hypoleuca, to find out how the availability of land snails varies along the pollution gradient. The total snail shell mass increased towards the pollution source but declined abruptly in the vicinity of the smelter. This spatial variation in shell mass was evident also within a single snail species and could not be wholly explained by spatially varying snail numbers or species composition. Instead, the total shell mass was related to their shell size, individuals being largest at the moderately polluted areas. Smaller shell size suggests inferior growth of snails in the most heavily polluted area. Our study shows that pollution affects the diversity, abundance (available shell mass) and individual quality of land snails, posing reproductive problems for birds that rely on snails as calcium sources during breeding. There are probably both direct pollution-related (heavy metal and calcium levels) and indirect (habitat change) effects behind the observed changes in snail populations. Copyright 2010 Elsevier B.V. All rights reserved.

  19. Snail Farming in Mature Rubber Plantation : 4. Studies on some Artificial Methods for Hatching of Snail Eggs and Protection of Young Snails during the Dry Season

    Directory of Open Access Journals (Sweden)

    Awah, AA.

    2001-01-01

    Full Text Available Three species of edible land snails of the moist forest belt of Nigeria, Archachatina marginata (Swainson, Archachatina papyracae (Pfeiffer and two phenotypes of Limicolaria species, sometimes named Limicolaria flammae (Muller and Limicolaria aurora (Jay, were used in the study of three methods of artificial hatching of snail eggs and their young ones for the study of two methods of reduction of mortality during the dry season. The results of egg laying performance by the three species of snails showed a significantly (p <0.01 higher population explosion in a given breeding season for L. flammae/aurora than for either A. papyracae or A. marginata. The results of artificial methods for hatching of snail eggs indicated that the use of plastic containers, plus either loose topsoil or cotton wool for the incubator mediums or the use of cellophane containers (bag plus loose topsoil for the incubator medium, were in each case suitable for adoption in successful hatching of snail eggs artificially. Leaking coagulation pans or wooden boxes, half filled with heat sterilized loose topsoil and placed on the ground under shade of rubber tree canopy as dry season protection methods for the snails, were again in each case effective in the reduction of field mortality of the young snails. The survival rates were 100 % ; 90.6 % and 71.2 % for youngs of A. marginata, A. papyracae and L. flammae/aurora respectively. The results further indicated that the dry season protection method deemed optimum for the youngs of A. marginata may not necessarily be optimum for the youngs of either A. papyracae orL. flammae/aurora.

  20. Inquiry, Land Snails, and Environmental Factors.

    Science.gov (United States)

    Barrow, Lloyd H.; Krantz, Patrick D.

    2002-01-01

    Introduces land snails for use in inquiry-based science activities. Describes common characteristics and safety considerations while introducing students to land snails. Explains procedures for inquiry-based use of land snails in classrooms. (YDS)

  1. The convoluted evolution of snail chirality

    Science.gov (United States)

    Schilthuizen, M.; Davison, A.

    2005-11-01

    The direction that a snail (Mollusca: Gastropoda) coils, whether dextral (right-handed) or sinistral (left-handed), originates in early development but is most easily observed in the shell form of the adult. Here, we review recent progress in understanding snail chirality from genetic, developmental and ecological perspectives. In the few species that have been characterized, chirality is determined by a single genetic locus with delayed inheritance, which means that the genotype is expressed in the mother's offspring. Although research lags behind the studies of asymmetry in the mouse and nematode, attempts to isolate the loci involved in snail chirality have begun, with the final aim of understanding how the axis of left-right asymmetry is established. In nature, most snail taxa (>90%) are dextral, but sinistrality is known from mutant individuals, populations within dextral species, entirely sinistral species, genera and even families. Ordinarily, it is expected that strong frequency-dependent selection should act against the establishment of new chiral types because the chiral minority have difficulty finding a suitable mating partner (their genitalia are on the ‘wrong’ side). Mixed populations should therefore not persist. Intriguingly, however, a very few land snail species, notably the subgenus Amphidromus sensu stricto, not only appear to mate randomly between different chiral types, but also have a stable, within-population chiral dimorphism, which suggests the involvement of a balancing factor. At the other end of the spectrum, in many species, different chiral types are unable to mate and so could be reproductively isolated from one another. However, while empirical data, models and simulations have indicated that chiral reversal must sometimes occur, it is rarely likely to lead to so-called ‘single-gene’ speciation. Nevertheless, chiral reversal could still be a contributing factor to speciation (or to divergence after speciation) when

  2. An ecological study of Bithynia snails, the first intermediate host of Opisthorchis viverrini in northeast Thailand.

    Science.gov (United States)

    Wang, Yi-Chen; Ho, Richard Cheng Yong; Feng, Chen-Chieh; Namsanor, Jutamas; Sithithaworn, Paiboon

    2015-01-01

    Infection with the food-borne trematodiasis, liver fluke Opisthorchis viverrini, is a major public health concern in Southeast Asia. While epidemiology and parasitic incidence in humans are well studied, ecological information on the O. viverrini intermediate hosts remains limited. This study aimed to investigate the factors affecting the distribution and abundance of the first intermediate host, Bithynia siamensis goniomphalos snails. Water quality and snails were sampled in 31 sites in Muang District, Khon Kaen Province, Thailand from June 2012 to January 2013 to characterize the B.s. goniomphalos snail habitats. Species relative abundance and Shannon's diversity and evenness indices were employed to describe snail compositions and diversities across different habitat types. Statistical analyses were conducted to examine the extent to which the water quality variables and species interactions account for the relative abundance of B.s. goniomphalos snails. The results showed that the freshwater habitats of ponds, streams and rice paddies possessed significantly different abiotic water qualities, with water temperature and pH showing distinct statistical differences (Psnail diversity and species evenness, with high B.s. goniomphalos snail abundance at rice paddy habitats. The differences in snail abundance might be due to the distinct sets of abiotic water qualities associated with each habitat types. The relative abundance of B.s. goniomphalos snails was found to be negatively correlated with that of Filopaludina martensi martensi snails (r=-0.46, Psnail population. Field work observations revealed that rice planting seasons and irrigation could regulate snail population dynamics at rice paddy habitats. This study provides new ecological insights into the factors affecting Bithynia snail distribution and abundance. It bridges the knowledge gap in O. viverrini disease ecology and highlights the potential effect of anthropogenic irrigation practices on B

  3. The competitive interaction of snails Thiara scabra and Physa doopi on the snail Lymnaea rubiginosa under laboratory conditions

    Directory of Open Access Journals (Sweden)

    Sarwitri Endah Estuningsih

    1998-03-01

    Full Text Available The competitive interaction of the snails Thiara scabra and Physa doopi against the snail Lymnaea rubiginosa, the intermediate host ofFasciola gigantica has been studied. Aquaria, 60 x 40 x 20 cm and 30 x 20 x 10 cm in size were used, and the two snail species were introduced in different proportion . The results over a one year period showed that the competition between snail L. rubiginosa and T. scabra or P. doopi has started after 8 months as demonstrated by the reduction of the population ofL. rubiginosa and increasing the population of T. scabra or P. doopi. The competitive interaction does not seem to be due to competition for food but to a chemical factors, possibly water-soluble pheromones. The other explanation is discussed .

  4. The Lazy Snail

    Institute of Scientific and Technical Information of China (English)

    范丽萍

    2007-01-01

    @@ 一、故事内容 Once upon a time,there was a snail.He lived in a very poor place.There were some holes in the roof.In summer,it was very hot.If it rained outside,it rained inside,too.In winter,it was very cold.The winds came through the broken window.

  5. Hormone-like peptides in the venoms of marine cone snails

    DEFF Research Database (Denmark)

    Robinson, Samuel D.; Li, Qing; Bandyopadhyay, Pradip K.

    2017-01-01

    The venoms of cone snails (genus Conus) are remarkably complex, consisting of hundreds of typically short, disulfide-rich peptides termed conotoxins. These peptides have diverse pharmacological targets, with injection of venom eliciting a range of physiological responses, including sedation...... in the venoms of cone snails we systematically mined the venom gland transcriptomes of several cone snail species and examined secreted venom peptides in dissected and injected venom of the Australian cone snail Conus victoriae. Using this approach we identified several novel hormone/neuropeptide-like toxins...

  6. Removal of corallivorous snails as a proactive tool for the conservation of acroporid corals

    Directory of Open Access Journals (Sweden)

    Dana E. Williams

    2014-11-01

    Full Text Available Corallivorous snail feeding is a common source of tissue loss for the threatened coral, Acropora palmata, accounting for roughly one-quarter of tissue loss in monitored study plots over seven years. In contrast with larger threats such as bleaching, disease, or storms, corallivory by Coralliophila abbreviata is one of the few direct sources of partial mortality that may be locally managed. We conducted a field experiment to explore the effectiveness and feasibility of snail removal. Long-term monitoring plots on six reefs in the upper Florida Keys were assigned to one of three removal treatments: (1 removal from A. palmata only, (2 removal from all host coral species, or (3 no-removal controls. During the initial removal in June 2011, 436 snails were removed from twelve 150 m2 plots. Snails were removed three additional times during a seven month “removal phase”, then counted at five surveys over the next 19 months to track recolonization. At the conclusion, snails were collected, measured and sexed. Before-After-Control-Impact analysis revealed that both snail abundance and feeding scar prevalence were reduced in removal treatments compared to the control, but there was no difference between removal treatments. Recolonization by snails to baseline abundance is estimated to be 3.7 years and did not differ between removal treatments. Recolonization rate was significantly correlated with baseline snail abundance. Maximum snail size decreased from 47.0 mm to 34.6 mm in the removal treatments. The effort required to remove snails from A. palmata was 30 diver minutes per 150 m2 plot, compared with 51 min to remove snails from all host corals. Since there was no additional benefit observed with removing snails from all host species, removals can be more efficiently focused on only A. palmata colonies and in areas where C. abbreviata abundance is high, to effectively conserve A. palmata in targeted areas.

  7. Field prevalence and laboratory susceptibility of southern Australian land snails to Brachylaima cribbi sporocyst infection

    Directory of Open Access Journals (Sweden)

    Butcher A.R.

    2003-06-01

    Full Text Available Brachylaima cribbi is a terrestrial trematode of birds and mammals with helic id and hygromild land snails reported as first and second Intermediate hosts. However, reports describing the first Intermediate host range of B. cribbi have been limited to those snail species present In a small number of geographical locations In South Australia. The natural first Intermediate host range, distribution and prevalence of B. cribbi In land snails In southern Australia were determined. A total of 6,432 introduced and native land snails were collected from eight geographical districts across 3,000 km of southern Australia and examined microscopically for B. cribbi sporocysts. Four Introduced European snails, Theba pisana, Cernuella virgata, Cochlicella acuta and Cochlicella barbara were natural first Intermediate hosts. Sporocyst-infected snails were detected In all districts from Victoria to the west coast of South Australia, a distance of over 1,300 km. Natural sporocyst infection was not observed in introduced European snails Microxeromagna armillata and Helix aspersa or In native Australian land snails Succinea australis and Strangesta gawleri. Egg feeding experiments in the laboratory with B. cribbi confirmed the susceptibility of those species of snails found to be natural first intermediate hosts. Of those species not found to be Infected In nature, only M. armillata could be Infected In the laboratory. Although this study has shown that five different species of European land snails are suitable first Intermediate hosts for B. cribbi there are as yet no reports of B. cribbi from these snails In Europe or from other countries where they have been introduced. Further Investigations are needed in Europe to clarify the origins of this parasite.

  8. How stress alters memory in 'smart' snails.

    Directory of Open Access Journals (Sweden)

    Sarah Dalesman

    Full Text Available Cognitive ability varies within species, but whether this variation alters the manner in which memory formation is affected by environmental stress is unclear. The great pond snail, Lymnaea stagnalis, is commonly used as model species in studies of learning and memory. The majority of those studies used a single laboratory strain (i.e. the Dutch strain originating from a wild population in the Netherlands. However, our recent work has identified natural populations that demonstrate significantly enhanced long-term memory (LTM formation relative to the Dutch strain following operant conditioning of aerial respiratory behaviour. Here we assess how two populations with enhanced memory formation (i.e. 'smart' snails, one from Canada (Trans Canada 1: TC1 and one from the U.K. (Chilton Moor: CM respond to ecologically relevant stressors. In control conditions the Dutch strain forms memory lasting 1-3 h following a single 0.5 h training session in our standard calcium pond water (80 mg/l [Ca(2+], whereas the TC1 and CM populations formed LTM lasting 5+ days following this training regime. Exposure to low environmental calcium pond water (20 mg/l [Ca(2+], which blocks LTM in the Dutch strain, reduced LTM retention to 24 h in the TC1 and CM populations. Crowding (20 snails in 100 ml immediately prior to training blocks LTM in the Dutch strain, and also did so in TC1 and CM populations. Therefore, snails with enhanced cognitive ability respond to these ecologically relevant stressors in a similar manner to the Dutch strain, but are more robust at forming LTM in a low calcium environment. Despite the two populations (CM and TC1 originating from different continents, LTM formation was indistinguishable in both control and stressed conditions. This indicates that the underlying mechanisms controlling cognitive differences among populations may be highly conserved in L. stagnalis.

  9. Larval stages of digenetic trematodes in Melanopsis praemorsa snails from freshwater bodies in Palestine

    Institute of Scientific and Technical Information of China (English)

    Sami Bdir; Ghaleb Adwan

    2011-01-01

    Objective: To detect the species of larval trematodes (cercariae) in Melanopsis praemorsa snails from 5 different fresh water bodies in Palestine. Methods: A total of 1 880 Melanopsis praemorsa snails were collected from different fresh water bodies in Palestine from October, 2008 to November, 2010. Cercariae in Melanopsis praemorsa snails were obtained by lighting and crushing methods. The behavior of cercariae was observed using a dissecting microscope. Results: Three different species of larval trematodes were identified from Melanopsis praemorsa snails collected only from Al-Bathan fresh water body, while snails from other water bodies were not infected. These species were microcercous cercaria, xiphidiocercaria and brevifurcate lophocercous cercaria. These cercariae called Cercaria melanopsi palestinia I, Cercaria melanopsi palestinia II and Cercaria melanopsi palestinia III have not been described before from this snail in Palestine. The infection rate of Melanopsis praemorsa collected from Al-Bathan fresh water body was 5.7%, while the overall infection rate of snails collected from all fresh water bodies was 4.3%. Details are presented on the morphology and behavior of the cercariae as well as their development within the snail. Conclusions: These results have been recorded for the first time and these cercariae may be of medical and veterinary importance.

  10. Pseudosuccinea columella: experimental co-infections of juvenile and pre-adult snails with the digeneans Calicophoron daubneyi and Fasciola hepatica.

    Science.gov (United States)

    Dreyfuss, G; Vignoles, P; Rondelaud, D

    2016-11-01

    Experimental co-infections of juvenile and pre-adult Pseudosuccinea columella with Calicophoron daubneyi and Fasciola hepatica (five miracidia of each digenean per snail) were carried out to determine the aptitude of this lymnaeid to ensure complete larval development of the former parasite, the latter or both. Snails infected with F. hepatica were found in the two groups of juveniles, i.e. 1 and 2 mm at exposure, and the four groups of pre-adults, i.e. 3-6 mm. The highest frequency of F. hepatica, i.e. 37.3%, was noted in the 4 mm group. Low frequencies were noted for C. daubneyi and co-infections of both digeneans in the 3, 4 and 5 mm groups. Two other groups of P. columella, measuring 3 and 4 mm at exposure, were also constituted to study the characteristics of these co-infections. Compared to controls infected only with F. hepatica, the frequency of this digenean infection and the mean number of metacercariae were significantly lower in co-infected snails, while the patent period was significantly shorter. In snails harbouring C. daubneyi only or both digeneans, lower values were noted for prevalence, the patent period and the number of metacercariae. Pre-adult P. columella (3-5 mm in shell height at exposure) were able to sustain larval development of C. daubneyi if they were co-infected with the sequence C. daubneyi +F. hepatica. Low values noted for the prevalence of C. daubneyi infection and the number of metacercariae would be in favour of a still incomplete adaptation between the snail population and the miracidial isolate.

  11. Chlorophyllin Bait Formulation and Exposure to Different Spectrum of Visible Light on the Reproduction of Infected/Uninfected Snail Lymnaea acuminata

    Directory of Open Access Journals (Sweden)

    Navneet Kumar

    2016-01-01

    Full Text Available Fasciolosis is a waterborne disease, caused by Fasciola species. Snail Lymnaea acuminata is an intermediate host of these flukes. Control of snail population is major tool in reducing the incidences. Variation in light intensity and wavelength caused significant changes in reproduction pattern of snails. Maximum fecundity was noted with bait containing carbohydrate (starch, 468 ± 0.10/20 snails or amino acid (serine, 319 ± 0.29/20 snails as attractant. Sublethal feeding of chlorophyllin bait with starch or serine attractant to infected and uninfected snails caused significant reduction in fecundity, hatchability, and survivability. These significant changes are observed in snails exposed to different spectral band of visible light and sunlight. Maximum fecundity of 536 ± 2.0 and minimum of 89.3 ± 0.4 were noted in snails not fed with bait and exposed to sunlight and red spectral band, respectively. There was complete arrest in the fecundity of infected and uninfected snails and no survivability of uninfected snails after 48 h feeding with bait containing chlorophyllin + attractant. Minimum hatchability (9.25 ± 0.5 was noted in red light exposed, chlorophyllin + starch fed infected snails and hatching period of bait fed snails was prolonged. Conclusively, chlorophyllin bait and red light reduce reproduction capacity in snails.

  12. Chlorophyllin Bait Formulation and Exposure to Different Spectrum of Visible Light on the Reproduction of Infected/Uninfected Snail Lymnaea acuminata.

    Science.gov (United States)

    Kumar, Navneet; Singh, D K; Singh, Vinay Kumar

    2016-01-01

    Fasciolosis is a waterborne disease, caused by Fasciola species. Snail Lymnaea acuminata is an intermediate host of these flukes. Control of snail population is major tool in reducing the incidences. Variation in light intensity and wavelength caused significant changes in reproduction pattern of snails. Maximum fecundity was noted with bait containing carbohydrate (starch, 468 ± 0.10/20 snails) or amino acid (serine, 319 ± 0.29/20 snails) as attractant. Sublethal feeding of chlorophyllin bait with starch or serine attractant to infected and uninfected snails caused significant reduction in fecundity, hatchability, and survivability. These significant changes are observed in snails exposed to different spectral band of visible light and sunlight. Maximum fecundity of 536 ± 2.0 and minimum of 89.3 ± 0.4 were noted in snails not fed with bait and exposed to sunlight and red spectral band, respectively. There was complete arrest in the fecundity of infected and uninfected snails and no survivability of uninfected snails after 48 h feeding with bait containing chlorophyllin + attractant. Minimum hatchability (9.25 ± 0.5) was noted in red light exposed, chlorophyllin + starch fed infected snails and hatching period of bait fed snails was prolonged. Conclusively, chlorophyllin bait and red light reduce reproduction capacity in snails.

  13. Chlorophyllin Bait Formulation and Exposure to Different Spectrum of Visible Light on the Reproduction of Infected/Uninfected Snail Lymnaea acuminata

    Science.gov (United States)

    Kumar, Navneet; Singh, D. K.; Singh, Vinay Kumar

    2016-01-01

    Fasciolosis is a waterborne disease, caused by Fasciola species. Snail Lymnaea acuminata is an intermediate host of these flukes. Control of snail population is major tool in reducing the incidences. Variation in light intensity and wavelength caused significant changes in reproduction pattern of snails. Maximum fecundity was noted with bait containing carbohydrate (starch, 468 ± 0.10/20 snails) or amino acid (serine, 319 ± 0.29/20 snails) as attractant. Sublethal feeding of chlorophyllin bait with starch or serine attractant to infected and uninfected snails caused significant reduction in fecundity, hatchability, and survivability. These significant changes are observed in snails exposed to different spectral band of visible light and sunlight. Maximum fecundity of 536 ± 2.0 and minimum of 89.3 ± 0.4 were noted in snails not fed with bait and exposed to sunlight and red spectral band, respectively. There was complete arrest in the fecundity of infected and uninfected snails and no survivability of uninfected snails after 48 h feeding with bait containing chlorophyllin + attractant. Minimum hatchability (9.25 ± 0.5) was noted in red light exposed, chlorophyllin + starch fed infected snails and hatching period of bait fed snails was prolonged. Conclusively, chlorophyllin bait and red light reduce reproduction capacity in snails. PMID:26925296

  14. Land snails (Mollusca: Gastropoda of India: status, threats and conservation strategies

    Directory of Open Access Journals (Sweden)

    S. Sen

    2012-09-01

    Full Text Available Land snails form an important component in the forest ecosystem. In terms of number of species, the phylum Mollusca, to which land snails belong, is the largest phylum after Arthropoda. Mollusca provide unique ecosystem services including recycling of nutrients and they provide a prey base for small mammals, birds, snakes and other reptiles. However, land snails have the largest number of documented extinctions, compared to any other taxa. Till date 1,129 species of land snails are recorded from Indian territory. But only basic information is known about their taxonomy and little is known of their population biology, ecology and their conservation status. In this paper, we briefly review status, threats and conservation strategies of land snails of India.

  15. Population estimate of Chinese mystery snail (Bellamya chinensis) in a Nebraska reservoir

    Science.gov (United States)

    Chaine, Noelle M.; Allen, Craig R.; Fricke, Kent A.; Haak, Danielle M.; Hellman, Michelle L.; Kill, Robert A.; Nemec, Kristine T.; Pope, Kevin L.; Smeenk, Nicholas A.; Stephen, Bruce J.; Uden, Daniel R.; Unstad, Kody M.; VanderHam, Ashley E.

    2012-01-01

    The Chinese mystery snail (Bellamya chinensis) is an aquatic invasive species in North America. Little is known regarding this species' impacts on freshwater ecosystems. It is be lieved that population densities can be high, yet no population estimates have been reported. We utilized a mark-recapture approach to generate a population estimate for Chinese mystery snail in Wild Plum Lake, a 6.47-ha reservoir in southeast Nebraska. We calculated, using bias-adjusted Lincoln-Petersen estimation, that there were approximately 664 adult snails within a 127 m2 transect (5.2 snails/m2). If this density was consistent throughout the littoral zone (Chinese mystery snail wet biomass is estimated to be 3,119 kg (643 kg/ha). If this density is confined to the depth sampled in this study (1.46 m), then the adult population is estimated to be 169,400 snails, and wet biomass is estimated to be 2,084 kg (643 kg/ha). Additional research is warranted to further test the utility of mark-recapture methods for aquatic snails and to better understand Chinese mystery snail distributions within reservoirs.

  16. Epidemiology of cercarial stage of trematodes in freshwater snails from Chiang Mai province, Thailand

    Institute of Scientific and Technical Information of China (English)

    Thapana Chontananarth; Chalobol Wongsawad

    2013-01-01

    Objective: To investigate the epidemiological situation of cercarial trematodes infection in freshwater snails from different water resources in Chiang Mai province, Thailand. Methods:The snail specimens were collected from 13 districts of Chiang Mai province during April 2008 to February 2012. The prevalence of cercarial infection in snails was investigated using the crushing method. The drawing was done with the help of a camera lucida for the morphological study. Results:A total of 2 479 snail individuals were collected and classified into 7 families, 11 genera, and 14 species, Among them, 8 snails species were found to be infected with an overall prevalence of 17.27% (428/2 479), which infected with nine groups of cercariae;gymnocephalous cercaria, strigea cercaria, megalurous cercaria, monostome cercaria, parapleurolophocercous cercaria (Haplorchis cercaria), pleurolophocercous cercaria, furcocercous cercaria (Transversotrema cercaria), xiphidiocercaria, and virgulate cercaria. The parapleurolophocercous cercaria was found to be the dominant type among the cercarial infection in the snails (64.25%). Conclusions:The various species of snails found in the research location act as the intermediate hosts for the high prevalence of parasitic infection of many species of mammals. This work will provide new information on both the distribution and first intermediate host of trematodes.

  17. Characteristics of snail farming in Edo South Agricultural Zone of Edo State, Nigeria.

    Science.gov (United States)

    Chah, Jane Mbolle; Inegbedion, Grace

    2013-02-01

    The study was carried out to determine the characteristics of snail farming in Edo South Agricultural Zone of Edo State Nigeria. The interview schedule was used to collect data from 60 snail farmers randomly selected from six cells in the study area. Information on the socioeconomic status of the farmers, production system, management practices and production constraints in the snail farms were elicited. The constraints were determined using a four-point Likert-type scale; a mean score of ≥ 2.5 was considered as a production constraint. Majority (85.0 %) of the respondents were part-time snail farmers. The major species of snails reared were Achatina achatina and Archachatina marginata, reared by 43.3 and 26.7 % of the farmers, respectively. Semi-intensive system of production was practised by 40.0 % of the farmers. Majority (78.0 %) of the respondents used car tyres to house their snails. About 56 % of the respondents kept their snails for 1-2 years before sale. Up to 51.7 % of the respondents separated their snails into different pens according to their size/age. The most commonly used feeds were vegetables (71.2 %), plant leaves (67.8 %) and kitchen waste (59.3 %). Records of snail production activities were kept by 75.0 % of respondents. The major constraints identified were lack of capital (3.31), inability to get good laying stock (3.00), lack of formulated feed to buy (2.98) and slow growth rate of snails (2.52). The potentials of snail farming in the study area have not been fully exploited as farmers produced at subsistence level.

  18. Multiple infection of amber Succinea putris snails with sporocysts of Leucochloridium spp. (Trematoda).

    Science.gov (United States)

    Ataev, G L; Zhukova, A A; Tokmakova, А S; Prokhorova, Е E

    2016-08-01

    Amber Succinea putris snails were collected in the Leningrad Region (Russia). Some of them were infected with trematodes Leucochloridium paradoxum, Leucochloridium perturbatum and Leucochloridium vogtianum. One snail had triple infection with all these species. Genotyping of sporocysts by ITS1-5.8S-ITS2 nucleotide sequences of ribosomal DNA (rDNA) and phylogenetic analysis were performed. The results confirmed the species identification of sporocysts of Leucochloridium based on the shape and colour of mature broodsacs. Sporocyst broodsacs could leave the host snail on their own, remaining viable in the environment for up to an hour. This ability of sporocysts may prevent the excessive infection of the molluscan host.

  19. Molecular diversity of avian schistosomes in Danish freshwater snails.

    Science.gov (United States)

    Christiansen, Anne Ø; Olsen, Annette; Buchmann, Kurt; Kania, Per W; Nejsum, Peter; Vennervald, Birgitte J

    2016-03-01

    Avian schistosomes are widespread parasites of snails and waterfowl and may cause cercarial dermatitis (swimmer's itch) in humans, a disease that is frequently reported in European countries. These parasites are known to occur in Denmark, but here, we applied a new approach using molecular tools to identify the parasites at species level. In order to do that, 499 pulmonate freshwater snails (Radix sp., Lymnaea stagnalis, Stagnicola sp. and Planorbarius corneus) were sampled from 12 lakes, ponds, and marshes in the greater Copenhagen area. Avian schistosome cercariae were identified by microscopy and subjected to molecular investigation by sequencing and phylogenetic analysis of the 5.8S and ITS2 ribosomal DNA for species identification. Additionally, snail hosts belonging to the genus Radix were identified by sequencing and phylogenetic analysis of partial ITS2 ribosomal DNA. Three out of 499 snails shed different species of Trichobilharzia cercariae: Trichobilharzia szidati was isolated from L. stagnalis, Trichobilharzia franki from Radix auricularia and Trichobilharzia regenti from Radix peregra. In the light of the public health risk represented by bird schistosomes, these findings are of concern and, particularly, the presence of the potentially neuro-pathogenic species, T. regenti, in Danish freshwaters calls for attention.

  20. Spatially-resolved thermoluminescence from snail opercula using an EMCCD

    DEFF Research Database (Denmark)

    Duller, G.A.T.; Kook, Myung Ho; Stirling, R.J.

    2015-01-01

    In recent years opercula of the snail species Bithynia tentaculata have been shown to emit thermoluminescence (TL) signals that can be used to determine equivalent dose, and may be capable of dating events throughout the entire Quaternary period. Concentric growth lines are a notable feature...

  1. Implication of snail in metabolic stress-induced necrosis.

    Directory of Open Access Journals (Sweden)

    Cho Hee Kim

    Full Text Available BACKGROUND: Necrosis, a type of cell death accompanied by the rupture of the plasma membrane, promotes tumor progression and aggressiveness by releasing the pro-inflammatory and angiogenic cytokine high mobility group box 1. It is commonly found in the core region of solid tumors due to hypoxia and glucose depletion (GD resulting from insufficient vascularization. Thus, metabolic stress-induced necrosis has important clinical implications for tumor development; however, its regulatory mechanisms have been poorly investigated. METHODOLOGY/PRINCIPAL FINDINGS: Here, we show that the transcription factor Snail, a key regulator of epithelial-mesenchymal transition, is induced in a reactive oxygen species (ROS-dependent manner in both two-dimensional culture of cancer cells, including A549, HepG2, and MDA-MB-231, in response to GD and the inner regions of a multicellular tumor spheroid system, an in vitro model of solid tumors and of human tumors. Snail short hairpin (sh RNA inhibited metabolic stress-induced necrosis in two-dimensional cell culture and in multicellular tumor spheroid system. Snail shRNA-mediated necrosis inhibition appeared to be linked to its ability to suppress metabolic stress-induced mitochondrial ROS production, loss of mitochondrial membrane potential, and mitochondrial permeability transition, which are the primary events that trigger necrosis. CONCLUSIONS/SIGNIFICANCE: Taken together, our findings demonstrate that Snail is implicated in metabolic stress-induced necrosis, providing a new function for Snail in tumor progression.

  2. Ants as shell collectors: notes on land snail shells found around ant nests

    Directory of Open Access Journals (Sweden)

    Barna Páll-Gergely

    2009-03-01

    Full Text Available We investigated the shell collecting activities of harvester ants (Messor spp. in semi-arid grasslands and shrubs in Turkey. We found eleven species of snails in the area, two of them were not collected by ants. Eight – mainly small sized – snail species were found on ant nests in a habitat characterized by shrubs, three in rocky grassland and four in a grassland habitat. Some shells (e.g. Chondrus zebrula tantalus, Multidentula ovularis might be taken into the nests, and we hypothesise that some of these snail species are consumed by ants (Monacha spp.. From a fauna inventory perspective, shell collecting activities of harvester ant may help malacologists to find snail species which are normally hidden for a specialist (e.g. Oxychilus hydatinus, Cecilioides spp. due to their special habits.

  3. Distribution and abundance of schistosomiasis and fascioliasis host snails along the Mara River in Kenya and Tanzania

    Directory of Open Access Journals (Sweden)

    Gabriel O. Dida

    2014-10-01

    Full Text Available We purposively selected 39 sampling sites along the Mara River and its two perennial tributaries of Amala and Nyangores and sampled snails. In addition, water physicochemical parameters (temperature, turbidity, dissolved oxygen, conductivity, alkalinity, salinity and pH were taken to establish their influence on the snail abundance and habitat preference. Out of the 39 sites sampled, 10 (25.6% had snails. The snail species encountered included Biomphalaria pfeifferi Krauss – the intermediate host of Schistosoma mansoni Sambon, Bulinus africanus – the intermediate host of Schistosoma haematobium, and Lymnaea natalensis Krauss – the intermediate host of both Fasciola gigantica and F. hepatica Cobbold. Ceratophallus spp., a non-vector snail was also encountered. Most (61.0% of the snails were encountered in streamside pools. Schistosomiasis-transmitting host snails, B. pfeifferi and B. africanus, were fewer than fascioliasis-transmitting Lymnaea species. All the four different snail species were found to be attached to different aquatic weeds, with B. pfeifferi accounting for over half (61.1% of the snails attached to the sedge, followed by B. africanus and Lymnaea spp., accounting for 22.2 and 16.7%, respectively. Ceratophallus spp. were non-existent in sedge. The results from this preliminary study show that snails intermediate hosts of schistosomiasis and fascioliasis exists in different habitats, in few areas along the Mara River, though their densities are still low to have any noticeable impacts on disease transmission in case they are infected. The mere presence of the vector snails in these focal regions calls for their immediate control and institution of proper regulations, management, and education among the locals that can help curtail the spread of the snails and also schistosomiasis and fascioliasis within the Mara River basin.

  4. Distribution and abundance of schistosomiasis and fascioliasis host snails along the Mara River in Kenya and Tanzania.

    Science.gov (United States)

    Dida, Gabriel O; Gelder, Frank B; Anyona, Douglas N; Matano, Ally-Said; Abuom, Paul O; Adoka, Samson O; Ouma, Collins; Kanangire, Canisius K; Owuor, Phillip O; Ofulla, Ayub V O

    2014-01-01

    We purposively selected 39 sampling sites along the Mara River and its two perennial tributaries of Amala and Nyangores and sampled snails. In addition, water physicochemical parameters (temperature, turbidity, dissolved oxygen, conductivity, alkalinity, salinity and pH) were taken to establish their influence on the snail abundance and habitat preference. Out of the 39 sites sampled, 10 (25.6%) had snails. The snail species encountered included Biomphalaria pfeifferi Krauss - the intermediate host of Schistosoma mansoni Sambon, Bulinus africanus - the intermediate host of Schistosoma haematobium, and Lymnaea natalensis Krauss - the intermediate host of both Fasciola gigantica and F. hepatica Cobbold. Ceratophallus spp., a non-vector snail was also encountered. Most (61.0%) of the snails were encountered in streamside pools. Schistosomiasis-transmitting host snails, B. pfeifferi and B. africanus, were fewer than fascioliasis-transmitting Lymnaea species. All the four different snail species were found to be attached to different aquatic weeds, with B. pfeifferi accounting for over half (61.1%) of the snails attached to the sedge, followed by B. africanus and Lymnaea spp., accounting for 22.2 and 16.7%, respectively. Ceratophallus spp. were non-existent in sedge. The results from this preliminary study show that snails intermediate hosts of schistosomiasis and fascioliasis exists in different habitats, in few areas along the Mara River, though their densities are still low to have any noticeable impacts on disease transmission in case they are infected. The mere presence of the vector snails in these focal regions calls for their immediate control and institution of proper regulations, management, and education among the locals that can help curtail the spread of the snails and also schistosomiasis and fascioliasis within the Mara River basin.

  5. Exploring the temporal effects of seasonal water availability on the snail kite of Florida: Part III

    Science.gov (United States)

    Mooij, Wolf M.; Martin, Julien; Kitchens, Wiley M.; DeAngelis, Donald L.; Bissonette, John A.; Storch, Ilse

    2007-01-01

    The Florida snail kite (Rostrhamus sociabilis) is an endangered raptor that occurs as an isolated population, currently of about 2,000 birds, in the wetlands of southern and central Florida, USA. Its exclusive prey species, the apple snail (Pomacea paludosa) is strongly influenced by seasonal changes in water abundance. Droughts during the snail kite breeding season have a direct negative effect on snail kite survival and reproduction, but droughts are also needed to maintain aquatic vegetation types favorable to snail kite foraging for snails. We used a spatially explicit matrix model to explore the effects of temporal variation in water levels on the viability of the snail kite population under different temporal drought regimes in its wetland breeding habitat. We focused on three aspects of variations in water levels that were likely to affect kites: (1) drought frequency; (2) drought duration; and (3) drought timing within the year. We modeled a 31-year historical scenario using four different scenarios in which the average water level was maintained constant, but the amplitude of water level fluctuations was modified. Our results reveal the complexity of the effects of temporal variation in water levels on snail kite population dynamics. Management implications of these results are discussed. In particular, management decisions should not be based on annual mean water levels alone, but must consider the intra-annual variability.

  6. Identification of Medically Important Snails of Miangran Lake in Izeh, Khuzestan Province of Iran

    Directory of Open Access Journals (Sweden)

    Valipour Nouroozi

    2015-11-01

    Full Text Available Background Some freshwater snails are acting as intermediate hosts for digenetic trematodes. Studies on distribution of freshwater snails are important to determine the transmission patterns of the trematoda. Objectives The current study aimed to identify medically important snails of Miangran Lake in Izeh, Khuzestan province, Iran. Materials and Methods Sampling was conducted in fourteen sites around Miangran Lake in 2014. The collected samples were placed in plastic containers containing 70% ethyl alcohol, prior to consideration. The identification was carried out according to shell characteristics. Data were analyzed descriptively. Results All sampling sites were positive for medically important snails. Overall, nine genera and thirteen species were identified. The most diversity in genus was found in Melanopsis. Five genera of snails detected in the study with known medical importance include: Bithynia spp., Bulinus spp., Lymnaea spp., Melanoides spp. and Melanopsis spp. Melanoides spp. was observed in thirteen and Bellamya spp. was identified in two sites. Also, in this study Melanoides spp., Bulinus spp., and Lymnaea spp. were widespread snails around Miangran Lake. Conclusions The reason for difference in the detected snail genera in sampling sites may be due to various physicochemical factors. According to the current study, medically important snails exist in Miangran Lake and they could be a source of trematode infections for the local people. Controlling measures after comprehensive studies should be applied.

  7. Calcareous forest seepages acting as biodiversity hotspots and refugia for woodland snail faunas

    Science.gov (United States)

    Horsák, Michal; Tajovská, Eva; Horsáková, Veronika

    2017-07-01

    Land-snail species richness has repeatedly been found to increase with the increasing site calcium content and humidity. These two factors, reported as the main drivers of land-snail assemblage diversity, are also among the main habitat characteristics of calcareous seepages. Here we explore local species richness and compositional variation of forest spring-fed patches (i.e. seepages), to test the hypothesis that these habitats might act as biodiversity hotspots and refugia of regional snail faunas. In contrast to treeless spring fens, only little is known about land snail faunas inhabiting forest seepages. Studying 25 isolated calcareous forest seepages, evenly distributed across the White Carpathians Protected Landscape Area (SE Czech Republic), we found that these sites, albeit spatially very limited, can harbour up to 66% of the shelled land-snail species known to occur in this well-explored protected area (in total 83 species). By comparing land snail assemblages of the studied seepages with those occurring in the woodland surroundings of each site as well as those previously sampled in 28 preserved forest sites within the study area, we found the seepages to be among the most species rich sites. Although the numbers of species did not statistically differ among these three systems, we found highly significant differences in species composition. Seepage faunas were composed of many species significantly associated with spring sites, in contrast to the assemblages of both surrounding and preserved forest sites. Our results highly support the hypothesis that calcareous forest seepages might serve as refugia and biodiversity hotspots of regional land snail faunas. Protection of these unique habitats challenges both conservation plans and forest management guidelines as they might act as sources for the recolonization and restoration of forest snail assemblages particularly in areas impoverished by harvesting and clearcutting.

  8. Impacts of Thermal Treatments on Major and Minor Allergens of Sea Snail, Cerithidea obtusa (Obtuse Horn Shell

    Directory of Open Access Journals (Sweden)

    Rosmilah Misnan

    2016-08-01

    Full Text Available Snail is one of the worst causes of food allergy. Thus, the aim of this study was to identify the major and minor allergens of the local marine snail (Cerithidea obtusa and subsequently to investigate the impacts of heat treatment on the IgE-binding activity of snail allergens. Proteins from raw and heat-treated snails (boiled, roasted and fried were extracted and then resolved by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE. Immunoblotting of all extracts were then performed using sera from patients with snail allergy. The results showed that the raw extract contains numerous protein bands between 12 to>250 kDa. Some thermostable proteins, predominantly the 33 and 42 kDa bands, remained detected in all cooked extracts with decreasing intensities from boiled to roasted to fried extracts, while the majority of thermolabile bands denatured after heating. Boiled snail had more protein bands compared to roasted and fried snails. Immunoblotting of raw extract demostrated 19 IgE-binding bands ranging from 15 to 240 kDa. The thermostable bands of 33 and 42 kDa and a thermolabile of 30 kDa band were identified as the major allergens of this snail. The cooked extracts yielded less allergenic bands. The boiled extract yielded approximately 14 IgE-binding bands with some smeared bands at high molecular weight regions. The roasted extract had lesser IgE-binding bands and the majority appeared as smears, while the IgE-reactivity in the fried extract was less visible and appeared as weak smears. This study indicated that both raw and cooked snails played a crucial role in snail allergenicity, as this species of snail contains both thermostable and thermolabile major allergens. The degree of snail allergenicity was revealed in the order: raw> boiled > roasted> fried. Thus, the results would facilitate in the development of effective diagnosis and management strategies of snail allergy in this country

  9. Survival and growth of freshwater pulmonate and nonpulmonate snails in 28-day exposures to copper, ammonia, and pentachlorophenol

    Science.gov (United States)

    Besser, John M.; Dorman, Rebecca A.; Hardesty, Douglas K.; Ingersoll, Christopher G.

    2016-01-01

    We performed toxicity tests with two species of pulmonate snails (Lymnaea stagnalis and Physa gyrina) and four taxa of nonpulmonate snails in the family Hydrobiidae (Pyrgulopsis robusta,Taylorconcha serpenticola, Fluminicola sp., and Fontigens aldrichi). Snails were maintained in static-renewal or recirculating culture systems with adults removed periodically to isolate cohorts of offspring for toxicity testing. This method successfully produced offspring for both species of pulmonate snails and for two hydrobiid species, P. robusta and Fluminicola sp. Toxicity tests were performed for 28 days with copper, ammonia, and pentachlorophenol in hard reconstituted water with endpoints of survival and growth. Tests were started with 1-week-old L. stagnalis, 2-week-old P. gyrina, 5- to 13-week-old P. robusta and Fluminicola sp., and older juveniles and adults of several hydrobiid species. For all three chemicals, chronic toxicity values for pulmonate snails were consistently greater than those for hydrobiid snails, and hydrobiids were among the most sensitive taxa in species sensitivity distributions for all three chemicals. These results suggest that the toxicant sensitivity of nonpulmonate snails in the family Hydrobiidae would not be adequately represented by results of toxicity testing with pulmonate snails.

  10. Survival and Growth of Freshwater Pulmonate and Nonpulmonate Snails in 28-Day Exposures to Copper, Ammonia, and Pentachlorophenol.

    Science.gov (United States)

    Besser, John M; Dorman, Rebecca A; Hardesty, Douglas L; Ingersoll, Christopher G

    2016-02-01

    We performed toxicity tests with two species of pulmonate snails (Lymnaea stagnalis and Physa gyrina) and four taxa of nonpulmonate snails in the family Hydrobiidae (Pyrgulopsis robusta, Taylorconcha serpenticola, Fluminicola sp., and Fontigens aldrichi). Snails were maintained in static-renewal or recirculating culture systems with adults removed periodically to isolate cohorts of offspring for toxicity testing. This method successfully produced offspring for both species of pulmonate snails and for two hydrobiid species, P. robusta and Fluminicola sp. Toxicity tests were performed for 28 days with copper, ammonia, and pentachlorophenol in hard reconstituted water with endpoints of survival and growth. Tests were started with 1-week-old L. stagnalis, 2-week-old P. gyrina, 5- to 13-week-old P. robusta and Fluminicola sp., and older juveniles and adults of several hydrobiid species. For all three chemicals, chronic toxicity values for pulmonate snails were consistently greater than those for hydrobiid snails, and hydrobiids were among the most sensitive taxa in species sensitivity distributions for all three chemicals. These results suggest that the toxicant sensitivity of nonpulmonate snails in the family Hydrobiidae would not be adequately represented by results of toxicity testing with pulmonate snails.

  11. Molecular phylogeny and evolution of the cone snails (Gastropoda, Conoidea).

    Science.gov (United States)

    Puillandre, N; Bouchet, P; Duda, T F; Kauferstein, S; Kohn, A J; Olivera, B M; Watkins, M; Meyer, C

    2014-09-01

    We present a large-scale molecular phylogeny that includes 320 of the 761 recognized valid species of the cone snails (Conus), one of the most diverse groups of marine molluscs, based on three mitochondrial genes (COI, 16S rDNA and 12S rDNA). This is the first phylogeny of the taxon to employ concatenated sequences of several genes, and it includes more than twice as many species as the last published molecular phylogeny of the entire group nearly a decade ago. Most of the numerous molecular phylogenies published during the last 15years are limited to rather small fractions of its species diversity. Bayesian and maximum likelihood analyses are mostly congruent and confirm the presence of three previously reported highly divergent lineages among cone snails, and one identified here using molecular data. About 85% of the species cluster in the single Large Major Clade; the others are divided between the Small Major Clade (∼12%), the Conus californicus lineage (one species), and a newly defined clade (∼3%). We also define several subclades within the Large and Small major clades, but most of their relationships remain poorly supported. To illustrate the usefulness of molecular phylogenies in addressing specific evolutionary questions, we analyse the evolution of the diet, the biogeography and the toxins of cone snails. All cone snails whose feeding biology is known inject venom into large prey animals and swallow them whole. Predation on polychaete worms is inferred as the ancestral state, and diet shifts to molluscs and fishes occurred rarely. The ancestor of cone snails probably originated from the Indo-Pacific; rather few colonisations of other biogeographic provinces have probably occurred. A new classification of the Conidae, based on the molecular phylogeny, is published in an accompanying paper. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Freshwater snails (Mollusca: Gastropoda) from the Commonwealth of Dominica with a discussion of their roles in the transmission of parasites

    Science.gov (United States)

    We collected six species of freshwater snails from Dominica, including Biomphalaria kuhniana, Gundlachia radiata Helisoma (= Planorbella) trivolvis, Melanoides tuberculata, Neritina punctulata, and Physa marmorata. Our collections indicate that un-reported species such as Gundlachia radiata and Hel...

  13. Actividad molusquicida del Piquerol A aislado de Piqueria trinervia (compositae sobre ocho especies de caracoles pulmonados The molluscicide activity of Piquerol A isolated from Piqueria trinervia (Compositae against eight species of pulmonate snails

    Directory of Open Access Journals (Sweden)

    Alejandro Cruz-Reys

    1989-03-01

    Full Text Available De las partes aéreas de la planta Piqueria trinervia (Compositae colectada en diveresas áereas de México, se aisló el Piquerol A. Este compuesto se probó como agente molusquicida contra ocho especies de caracoles pulmonados: Fossaria (Fossaria humilis, F. (Bakerilymnae sp., Pseudosuccinea columella, Stagnicola attenuata, de México; F. (B. cubensis y Physacubensis, de Cuba; P. Columella y Biomphalaria glabrata, de Brasil; B glabrata, de Puerto Rico; S. elodes, de Estados Unidos. Se utilizaron tres concentraciones 50, 25 y 5 ppm para cada una de las especies y 2 períodos de exposición, 6 y 24 horas, a 20-22ºC. En 50 ppm, después de 6 horas, y 25 ppm, después de 24 horas los ejemplares de todas las especies murieron. En 5 ppm después de 24 horas, se observaron mortalidades de 60 a 100%. En ningún caso se observó recuperación después de la exposición por 24 horas. El piquerol A es un terpeno biodegradable que presenta otras actividades biológicas. No se han hecho pruebas de toxicidad en otros animales ni pruebas de campo. Sin embargo, es una substacia con alto potencial de uso como molusquicida en zonas de transmisión focal. Es la primera que en México se hacen estudios sistemáticos sobre molusquicidas de origen vegetal.In laboratory trials an aqueous solution of Piquerol A from Piqueria trinervia, collected in several regions of Mexico, showed a molluscicide action on the adults of eight different pulmonates snails species. Fossaria (Fossaria humilis, F. (Bakerilymnaea sp., Pseudosuccinea columella and Stagnicola attenuata from Mexico; F. (B. cubensis and Physa cubensis from Cuba; P. columella and Biomphalaria glabrata from Brazil; B. glabrata from Puerto Rico; and S. elodes from USA. The solution was tested at 50, 25 and 5 ppm concentration, for two periods of 6 and 24 hours, at room temperature (20-22ºC. A 100% mortality was obtained for all species at 50 ppm concentration after 6 hours of exposure; the same percentage at 25

  14. Snail1 Expression Is Required for Sarcomagenesis

    Directory of Open Access Journals (Sweden)

    Lorena Alba-Castellón

    2014-05-01

    Full Text Available Snail1 transcriptional repressor is a major inducer of epithelial-to mesenchymal transition but is very limitedly expressed in adult animals. We have previously demonstrated that Snail1 is required for the maintenance of mesenchymal stem cells (MSCs, preventing their premature differentiation. Now, we show that Snail1 controls the tumorigenic properties of mesenchymal cells. Increased Snail1 expression provides tumorigenic capabilities to fibroblastic cells; on the contrary, Snail1 depletion decreases tumor growth. Genetic depletion of Snail1 in MSCs that are deficient in p53 tumor suppressor downregulates MSC markers and prevents the capability of these cells to originate sarcomas in immunodeficient SCID mice. Notably, an analysis of human sarcomas shows that, contrarily to epithelial tumors, these neoplasms display high Snail1 expression. This is particularly clear for undifferentiated tumors, which are associated with poor outcome. Together, our results indicate a role for Snail1 in the generation of sarcomas.

  15. Host density increases parasite recruitment but decreases host risk in a snail-trematode system.

    Science.gov (United States)

    Buck, J C; Hechinger, R F; Wood, A C; Stewart, T E; Kuris, A M; Lafferty, K D

    2017-08-01

    Most species aggregate in local patches. High host density in patches increases contact rate between hosts and parasites, increasing parasite transmission success. At the same time, for environmentally transmitted parasites, high host density can decrease infection risk to individual hosts, because infective stages are divided among all hosts in a patch, leading to safety in numbers. We tested these predictions using the California horn snail, Cerithideopsis californica (=Cerithidea californica), which is the first intermediate host for at least 19 digenean trematode species in California estuaries. Snails become infected by ingesting trematode eggs or through penetration by free-swimming miracidia that hatch from trematode eggs deposited with final-host (bird or mammal) feces. This complex life cycle decouples infective-stage production from transmission, raising the possibility of an inverse relationship between host density and infection risk at local scales. In a field survey, higher snail density was associated with increased trematode (infected snail) density, but decreased trematode prevalence, consistent with either safety in numbers, parasitic castration, or both. To determine the extent to which safety in numbers drove the negative snail-density-trematode-prevalence association, we manipulated uninfected snail density in 83 cages at eight sites within Carpinteria Salt Marsh (California, USA). At each site, we quantified snail density and used data on final-host (bird and raccoon) distributions to control for between-site variation in infective-stage supply. After three months, overall trematode infections per cage increased with snail biomass density. For egg-transmitted trematodes, per-snail infection risk decreased with snail biomass density in the cage and surrounding area, whereas per-snail infection risk did not decrease for miracidium-transmitted trematodes. Furthermore, both trematode recruitment and infection risk increased with infective

  16. Host density increases parasite recruitment but decreases host risk in a snail-trematode system

    Science.gov (United States)

    Buck, Julia C; Hechinger, R.F.; Wood, A.C.; Stewart, T.E.; Kuris, A.M.; Lafferty, Kevin D.

    2017-01-01

    Most species aggregate in local patches. High host density in patches increases contact rate between hosts and parasites, increasing parasite transmission success. At the same time, for environmentally-transmitted parasites, high host density can decrease infection risk to individual hosts, because infective stages are divided among all hosts in a patch, leading to safety in numbers. We tested these predictions using the California horn snail, Cerithideopsis californica (=Cerithidea californica), which is the first intermediate host for at least 19 digenean trematode species in California estuaries. Snails become infected by ingesting trematode eggs or through penetration by free-swimming miracidia that hatch from trematode eggs deposited with final-host (bird or mammal) feces. This complex life cycle decouples infective-stage production from transmission, raising the possibility of an inverse relationship between host density and infection risk. In a field survey, higher snail density was associated with increased trematode (infected snail) density, but decreased trematode prevalence, consistent with either safety in numbers, parasitic castration, or both. To determine the extent to which safety in numbers drove the negative snail density-trematode prevalence association, we manipulated uninfected snail density in 83 cages at eight sites within Carpinteria Salt Marsh (CA, USA). At each site, we quantified snail density and used data on final-host (bird and raccoon) distributions to control for between-site variation in infective-stage supply. After three months, overall trematode infections per cage increased with snail-biomass density. For egg-transmitted trematodes, per-snail infection risk decreased with snail-biomass density in the cage and surrounding area, whereas per-snail infection risk did not decrease for miracidium-transmitted trematodes. Furthermore, both trematode recruitment and infection risk increased with infective-stage input, but this was

  17. Impact of invasive apple snails on the functioning and services of natural and managed wetlands

    Science.gov (United States)

    Horgan, Finbarr G.; Stuart, Alexander M.; Kudavidanage, Enoka P.

    2014-01-01

    At least 14 species of apple snail (Ampullariidae) have been released to water bodies outside their native ranges; however, less than half of these species have become widespread or caused appreciable impacts. We review evidence for the impact of apple snails on natural and managed wetlands focusing on those studies that have elucidated impact mechanisms. Significant changes in wetland ecosystems have been noted in regions where the snails are established: Two species in particular (Pomacea canaliculata and Pomacea maculata) have become major pests of aquatic crops, including rice, and caused enormous increases in molluscicide use. Invasive apple snails have also altered macrophyte community structure in natural and managed wetlands through selective herbivory and certain apple snail species can potentially shift the balance of freshwater ecosystems from clear water (macrophyte dominated) to turbid (plankton dominated) states by depleting densities of native aquatic plants. Furthermore, the introductions of some apple snail species have altered benthic community structure either directly, through predation, or indirectly, through exploitation competition or as a result of management actions. To date much of the evidence for these impacts has been based on correlations, with few manipulative field or mesocosm experiments. Greater attention to impact monitoring is required, and, for Asia in particular, a landscape approach to impact management that includes both natural and managed-rice wetlands is recommended.

  18. The maintenance of hybrids by parasitism in a freshwater snail.

    Science.gov (United States)

    Guttel, Yonathan; Ben-Ami, Frida

    2014-11-01

    Hybrids have often been labelled evolutionary dead-ends due to their lower fertility and viability. However, there is growing awareness that hybridisation between different species may play a constructive role in animal evolution as a means to create variability. Thus, hybridisation and introgression may contribute to adaptive evolution, for example with regards to natural antagonists (parasites, predators, competitors) and adaptation to local environmental conditions. Here we investigated whether parasite intensity contributes to the continuous recreation of hybrids in 74 natural populations of Melanopsis, a complex of freshwater snails with three species. We also examined, under laboratory conditions, whether hybrids and their parental taxa differ in their tolerance of low and high temperatures and salinity levels. Infections were consistently less prevalent in males than in females, and lower in snails from deeper habitats. Infection prevalence in hybrids was significantly lower than in the parental taxa. Low hybrid infection rates could not be explained by sediment type, snail density or geographic distribution of the sampling sites. Interestingly, infected hybrid snails did not show signs of parasite-induced gigantism, whereas all parental taxa did. We found that hybrids mostly coped with extreme temperatures and salinity levels as well as their parental taxa did. Taken together, our results suggest that Melanopsis hybrids perform better in the presence of parasites and environmental stress. This may explain the widespread and long-term occurrence of Melanopsis hybrids as evidenced by paleontological and biogeographic data. Hybridisation may be an adaptive host strategy, reducing infection rates and resisting gigantism.

  19. Does social facilitation affect responses to natural and anthropogenic stressors in the freshwater snail Planorbella trivolvis?

    Science.gov (United States)

    Plautz, Stephanie C; Salice, Christopher J

    2011-12-01

    Social facilitation is the initiation or increase of a trait, such as stressor tolerance, when in the presence of conspecifics, members of the same species. It has been shown to alter the outcome of toxicity experiments in colonial organisms. We evaluated whether social facilitation would impact responses to stressors in the noncolonial New Mexico ramshorn snail (Planorbella trivolvis) by exposing snails to stressors either singly or in groups of three. Social facilitation did not impact snail responses to malathion but did affect responses to predator cues and temperature stress. Copyright © 2011 SETAC.

  20. Ivermectin efficacy against Biomphalaria, intermediate host snail vectors of Schistosomiasis.

    Science.gov (United States)

    Katz, Naftale; Araújo, Neusa; Coelho, Paulo Marcos Zech; Morel, Carlos Medicis; Linde-Arias, Ana Rosa; Yamada, Takeshi; Horimatsu, Yuki; Suzuki, Koh; Sunazuka, Toshiaki; Ōmura, Satoshi

    2017-03-15

    The impact of ivermectin on adult snails of the genus Biomphalaria (B. glabrata, B. tenagophila and B. straminea), B. glabrata infected with Schistosoma mansoni, snail egg-masses cercariae and miracidia, as well as on guppy fish (Poecilia reticulata) was examined and evaluated. Biomphalaria snails, egg-masses, parasite stages and guppies were all exposed to different concentrations of ivermectin for 24 h, followed by regular observations of mortality. The calculated lethal doses of ivermectin were around an LD50 of 0.03 μg ml(-1), and an LD90 of 0.3 μg ml(-1) for the three species of snails. Specimens of B. glabrata actually shedding parasite cercariae all died when exposed to ivermectin at a concentration of a mere 0.01 μg ml(-1). Ivermectin B1a, the major (80%) component of commercially available ivermectin, proved to be inactive, and it was the minor (20%) component, ivermectin B1b, which caused snail death. Snail egg-masses were not affected, even at the highest concentration of 100 μg ml(-1). With respect to S. mansoni parasite stages, 0.2 μg ml(-1) ivermectin killed 50% of cercariae and miracidia within five minutes, rising to 90% after 30 min. Mortality of guppy fish within 24 h of exposure to ivermectin at concentrations of 0.5 μg ml(-1) and 0.01 μg ml(-1), were 100% and 30%, respectively. The concentration of 0.01 μg ml(-1) that killed Schistosoma mansoni-infected snails only caused 30% mortality in guppy fish. Ivermectin can be considered a promising molluscicide, especially as it is more potent against infected snails than uninfected ones, although it has no impact on egg-masses. Ivermectin and its derivatives could be explored in the search for a new agent to help control schistosomiasis transmission.The Journal of Antibiotics advance online publication, 15 March 2017; doi:10.1038/ja.2017.31.

  1. Large-scale determinants of intestinal schistosomiasis and intermediate host snail distribution across Africa

    DEFF Research Database (Denmark)

    Stensgaard, Anna-Sofie; Utzinger, Jürg; Vounatsou, Penelope

    2013-01-01

    to climate change. Here, we combine a growing degree day model for Schistosoma mansoni with species distribution models for the intermediate host snail (Biomphalaria spp.) to investigate large-scale environmental determinants of the distribution of the African S. mansoni-Biomphalaria system and potential...... impacts of climatic changes. Snail species distribution models included several combinations of climatic and habitat-related predictors; the latter divided into "natural" and "human-impacted" habitat variables to measure anthropogenic influence. The predictive performance of the combined snail......-parasite model was evaluated against a comprehensive compilation of historical S. mansoni parasitological survey records, and then examined for two climate change scenarios of increasing severity for 2080. Future projections indicate that while the potential S. mansoni transmission area expands, the snail ranges...

  2. Occurrence of a Snail Borne Disease, Cercarial Dermatitis (Swimmer Itch in Doon Valley (Uttarakhand, India.

    Directory of Open Access Journals (Sweden)

    Rakesh Kumar Jauhari

    2014-02-01

    Full Text Available 'Cercarial dermatitis' also known as swimmers itch (Skin allergies is caused by a trematode parasite, Schistosoma which has two hosts - an invertebrate (snail and a vertebrate (livestock, human being. Although the availability of both vector snails and pathogens at the selected site the Doon Valley in northern India has already been confirmed but there was a hazy picture of the disease, whether it is due to entrance of cercariae or due to wild variety of grass (Parthenium hysterophorus. The present study is an attempt to provide a way forward towards the vector snails and snail borne diseases in the study area.Snail sampling and identification was done by applying standard methods / using Keys & Catalogues. Associated parasites and cercariometry in snails has been worked out by cercarial shedding. Human involvement at zo-onotic level has been performed in collaboration with Health centers and socio- economic aspect of inhabitants of study area.The snail diversity encountered 19 species including the vector species such as Indoplanorbis exustus, Gyraulus convexiusculus, Melanoides tuberculata and Lymnaea acuminata. The cercarial diversity comprised Furcocercous, Monostome, Amphistome and liver fluke / Xiphidiocercaria. During the study (2009-2010, 0.173% was found with cercarial dermatitis among human population in the selected area. The symptoms of disease recorded were red spots and swellings on effected parts of skin. Frequent visits of livestock to the water body and presence of vector snails provides a clue in completing the life cycle of the parasite of the family Schistosomatidae.Cercarial dermatitis has been considered a potential risk at those places where warm blooded and snail's hosts share a link with aquatic bodies with particular emphasis to temperature and time of year.

  3. Spatial mosaic evolution of snail defensive traits

    Directory of Open Access Journals (Sweden)

    de León Francisco

    2007-03-01

    Full Text Available Abstract Background Recent models suggest that escalating reciprocal selection among antagonistically interacting species is predicted to occur in areas of higher resource productivity. In a putatively coevolved interaction between a freshwater snail (Mexipyrgus churinceanus and a molluscivorous cichlid (Herichthys minckleyi, we examined three components of this interaction: 1 spatial variation in two putative defensive traits, crushing resistance and shell pigmentation; 2 whether abiotic variables or frequency of molariform cichlids are associated with spatial patterns of crushing resistance and shell pigmentation and 3 whether variation in primary productivity accounted for small-scale variation in these defensive traits. Results Using spatial autocorrelation to account for genetic and geographic divergence among populations, we found no autocorrelation among populations at small geographic and genetic distances for the two defensive traits. There was also no correlation between abiotic variables (temperature and conductivity and snail defensive traits. However, crushing resistance and frequency of pigmented shells were negatively correlated with molariform frequency. Crushing resistance and levels of pigmentation were significantly higher in habitats dominated by aquatic macrophytes, and both traits are phenotypically correlated. Conclusion Crushing resistance and pigmentation of M. churinceanus exhibit striking variation at small spatial scales often associated with differences in primary productivity, substrate coloration and the frequency of molariform cichlids. These local geographic differences may result from among-habitat variation in how resource productivity interacts to promote escalation in prey defenses.

  4. The potential utility of nested PCR for investigation of Coxiella burnetii in Iranian snails

    OpenAIRE

    2016-01-01

    Objective: To detect the prevalence of Coxiella burnetii (C. burnetii) in two species of snails consisted of Lymnaea palustris (L. palustris) and Pomacea canaliculata (P. canaliculata) by using nested PCR method in Chaharmahel Va Bakhtiari Province which is located in the southwest of Iran. Methods: A total of 160 snail samples consisted of 100 L. palustris and 60 P. canaliculata were collected from 4 rice paddy fields in the southwest of Iran between June and August 2014. S...

  5. Shading decreases the abundance of the herbivorous California horn snail, Cerithidea californica

    Science.gov (United States)

    Lorda, Julio; Lafferty, Kevin D.

    2012-01-01

    Most of the intertidal zone in estuaries of California, USA and Baja California, Mexico is covered with vascular vegetation. Shading by these vascular plants influences abiotic and biotic processes that shape benthic community assemblages. We present data on the effects of shading on the California horn snail, Cerithidea californica. This species is important because it is the most common benthic macrofaunal species in these systems and acts as an obligate intermediate host of several species of rematode parasites that infect several other species. Using observational and experimental studies, we found a negative effect of shade on the distribution and abundance of the California horn snail. We hypothesized that shading reduces the abundance of the epipelic diatoms that the snails feeds on, causing snails to leave haded areas. We observed a negative relationship between vascular plant cover, sub-canopy light levels, and snail density in Mugu Lagoon. Then we experimentally manipulated light regimes, by clipping vegetation and adding shade structures, and found higher snail densities at higher light levels. In Goleta Slough, we isolated the effect of shade from vegetation by documenting a negative relationship between the shade created by two bridges and diatom and snail densities. We also found that snails moved the greatest distances over shaded channel banks compared to unshaded channel banks. Further, we documented the effect of water depth and channel bank orientation on shading in this system. An additional effect of shading is the reduction of temperature, providing an alternative explanation for some of our results. These results broaden our knowledge of how variation in the light environment influences the ecology of estuarine ecosystems.

  6. Taken to the limit--Is desiccation stress causing precocious encystment of trematode parasites in snails?

    Science.gov (United States)

    O'Dwyer, Katie; Poulin, Robert

    2015-12-01

    When hosts experience environmental stress, the quantity and quality of resources they provide for parasites may be diminished, and host longevity may be decreased. Under stress, parasites may adopt alternative strategies to avoid fitness reductions. Trematode parasites typically have complex life cycles, involving asexual reproduction in a gastropod first intermediate host. A rare phenomenon, briefly mentioned in the literature, and termed 'precocious encystment' involves the next stage in the parasites' life cycle (metacercarial cyst) forming within the preceding stage (redia), while still inside the snail. In the trematode Parorchis sp. NZ using rocky shore snails exposed to long periods outside water, we hypothesised that this might be an adaptive strategy against desiccation, preventing parasite emergence from the snail. To test this, we first investigated the effect of prolonged desiccation on the survival of two species of high intertidal snails. Secondly, we measured the reproductive output (cercarial production) of the parasite under wet and dry conditions. Finally, we quantified the influence of desiccation stress on the occurrence of precocious encystment. Snail mortality was higher under dry conditions, indicating stress, and it was somewhat exacerbated for infected snails. Parasite reproductive output differed between wet and dry conditions, with parasites of snails kept in dry conditions producing more cercariae when placed in water. Little variation was observed in the occurrence of precocious encystment, although some subtle patterns emerged. Given the stresses associated with living in high intertidal environments, we discuss precocious encystment as a possible stress response in this trematode parasite.

  7. Modelling climate change impact on the spatial distribution of fresh water snails hosting trematodes in Zimbabwe.

    Science.gov (United States)

    Pedersen, Ulrik B; Stendel, Martin; Midzi, Nicholas; Mduluza, Takafira; Soko, White; Stensgaard, Anna-Sofie; Vennervald, Birgitte J; Mukaratirwa, Samson; Kristensen, Thomas K

    2014-12-12

    Freshwater snails are intermediate hosts for a number of trematodes of which some are of medical and veterinary importance. The trematodes rely on specific species of snails to complete their life cycle; hence the ecology of the snails is a key element in transmission of the parasites. More than 200 million people are infected with schistosomes of which 95% live in sub-Saharan Africa and many more are living in areas where transmission is on-going. Human infection with the Fasciola parasite, usually considered more of veterinary concern, has recently been recognised as a human health problem. Many countries have implemented health programmes to reduce morbidity and prevalence of schistosomiasis, and control programmes to mitigate food-borne fascioliasis. As these programmes are resource demanding, baseline information on disease prevalence and distribution becomes of great importance. Such information can be made available and put into practice through maps depicting spatial distribution of the intermediate snail hosts. A biology driven model for the freshwater snails Bulinus globosus, Biomphalaria pfeifferi and Lymnaea natalensis was used to make predictions of snail habitat suitability by including potential underlying environmental and climatic drivers. The snail observation data originated from a nationwide survey in Zimbabwe and the prediction model was parameterised with a high resolution Regional Climate Model. Georeferenced prevalence data on urinary and intestinal schistosomiasis and fascioliasis was used to calibrate the snail habitat suitability predictions to produce binary maps of snail presence and absence. Predicted snail habitat suitability across Zimbabwe, as well as the spatial distribution of snails, is reported for three time slices representative for present (1980-1999) and future climate (2046-2065 and 2080-2099). It is shown from the current study that snail habitat suitability is highly variable in Zimbabwe, with distinct high- and low

  8. Malacological survey and geographical distribution of vector snails for schistosomiasis within informal settlements of Kisumu City, western Kenya

    Directory of Open Access Journals (Sweden)

    Opisa Selpha

    2011-12-01

    Full Text Available Abstract Background Although schistosomiasis is generally considered a rural phenomenon, infections have been reported within urban settings. Based on observations of high prevalence of Schistosoma mansoni infection in schools within the informal settlements of Kisumu City, a follow-up malacological survey incorporating 81 sites within 6 informal settlements of the City was conducted to determine the presence of intermediate host snails and ascertain whether active transmission was occurring within these areas. Methods Surveyed sites were mapped using a geographical information system. Cercaria shedding was determined from snails and species of snails identified based on shell morphology. Vegetation cover and presence of algal mass at the sites was recorded, and the physico-chemical characteristics of the water including pH and temperature were determined using a pH meter with a glass electrode and a temperature probe. Results Out of 1,059 snails collected, 407 (38.4% were putatively identified as Biomphalaria sudanica, 425 (40.1% as Biomphalaria pfeifferi and 227 (21.5% as Bulinus globosus. The spatial distribution of snails was clustered, with few sites accounting for most of the snails. The highest snail abundance was recorded in Nyamasaria (543 snails followed by Nyalenda B (313 snails. As expected, the mean snail abundance was higher along the lakeshore (18 ± 12 snails compared to inland sites (dams, rivers and springs (11 ± 32 snails (F1, 79 = 38.8, P Biomphalaria snails was higher in the inland (2.7% compared to the lakeshore sites (0.3% (P = 0.0109. B. sudanica was more abundant in sites along the lakeshore whereas B. pfeifferi and B. globosus were more abundant in the inland sites. Biomphalaria and Bulinus snails were found at 16 and 11 out of the 56 inland sites, respectively. Conclusions The high abundance of Biomphalaria and Bulinus spp. as well as observation of field-caught snails shedding cercariae confirmed that besides Lake

  9. Toxicity of copper sulfate and rotenone to Chinese mystery snail (Bellamya chinensis)

    Science.gov (United States)

    Haak, Danielle M.; Stephen, Bruce J.; Kill, Robert A.; Smeenk, Nicholas A.; Allen, Craig R.; Pope, Kevin L.

    2014-01-01

    The Chinese mystery snail (Bellamya chinensis) is a freshwater snail native to Southeast Asia, Japan, and Russia and is currently classified as an invasive species in at least 27 states in the USA. The species tolerates a wide range of environmental conditions, making management of established populations difficult. We tested the efficacy of two traditional chemical treatments, rotenone and copper sulfate, on the elimination of adult Chinese mystery snails in laboratory experiments. All snails (N=50) survived 72-hour exposure to rotenone-treated lake water, and 96% (N=25) survived 72-hour exposure to pre-determined rotenone concentrations of 0.25, 2.5, and 25.0 mg/L. All snails (N=10) survived exposure to 1.25 mg/L copper sulfate solution, 90% (N=10) survived exposure to 2.50 mg/L copper sulfate solution, and 80% (N=5) survived exposure to 5.0 mg/L copper sulfate solution. Neither rotenone nor copper sulfate effectively killed adult Chinese mystery snails in laboratory experiments, most likely due to their relatively large size, thick shell, and operculum. Therefore, it appears that populations will be very difficult to control once established, and management should focus on preventing additional spread or introductions of this species.

  10. Stable and clumped isotopes in shell carbonates of land snails Cathaica sp. and Bradybaena sp. in north China and implications for ecophysiological characteristics and paleoclimate studies

    Science.gov (United States)

    Wang, Xu; Cui, Linlin; Zhai, Jixuan; Ding, Zhongli

    2016-01-01

    Knowledge of ecophysiological characteristics of different land snail species is crucial for defining climatic significance of snail faunal assemblages. However, little work has been done in this aspect, hindering our obtaining unambiguous paleoclimatic information using these proxy indicators. Here we document for the first time the different ecophysiological characteristics of Cathaica sp. and Bradybaena sp. land snails using the stable isotopes and clumped isotope (Δ47) of the shell carbonates. The Δ47-derived temperatures for both species revealed a robust correlation with environmental temperatures. Moreover, the temperatures for Cathaica sp. are 3-5°C higher than those for Bradybaena sp. land snails, indicating different ecophysiological adaptations or growing seasons of the two species. Specifically, Cathaica sp. snails prefer living in a warm-humid summer, whereas Bradybaena sp. snails are active in the relatively cool-arid spring and/or autumn. The result testifies to the Δ47 in snail shell carbonates as a promising paleothermometer in monsoonal region and presents new insight into paleoclimatic explanation of these land snail species. This finding highlights the importance of climatic seasonality in the changes of the faunal assemblages of land snails.

  11. 淡水螺类三旋丽卷螺的物种鉴定及其潜在适生区分析%Species identification of freshwater snail Planorbella trivolvis and analysis of its potential distribution

    Institute of Scientific and Technical Information of China (English)

    李晓恒; 高世同; 顾文彪; 张仪; 郭云海

    2015-01-01

    Objective To identify the species classification of an ornamental Planorbidae from a flower market in Shanghai and analyze its potential distribution in China. Methods In August 2013,six freshwater snail specimens were collected from the Wanshang flower market. The species was identified by morphology and molecular biology. An ecological niche model was constructed based on the native geographic presence occurrence data,and projected onto the whole of China to predict the poten⁃tial distribution. Results Their shell external morphology suggested that the specimens belonged to Planorbella trivolvis(Say 1817)of Planorbidae,which is native in North America. The sequence data of a fragment of the mitochondrial cytochrome c oxi⁃dase subunit I(COI)confirmed its identification. A total of 2 294 georeferenced occurrence points in North America were car⁃ried out from the Global Biodiversity Information Facility databases and 614 records with coordinates were used to produce a North American native niche model by a maximum entropy method(Maxent). The projection on China results suggested high probabilities of occurrence mostly in Henan Province and its borderland with nearby provinces. Conclusions P. trivolvis is sim⁃ilarly with Biomphalaria species from shell morphology. It is the first records of the species in China,and the field dispersal is not clear.%目的:对上海市场销售的一种观赏性扁卷螺科淡水螺类进行物种鉴定,同时分析其在中国的潜在适生区。方法于2013年8月在上海市某花鸟市场购买6只淡水螺类标本,通过形态与分子生物学技术进行物种鉴定。运用生态小生境模型建立原产地模型,预测其在中国的潜在适宜生存区域。结果依据贝壳外部形态鉴定为扁卷螺科丽卷螺属三旋丽卷螺,查阅文献表明该物种原产地为北美地区,为广分布物种。通过线粒体细胞色素C氧化酶I(COI)基因片段序列的分子进化距离及系

  12. Analysis of snail genes in the crustacean Parhyale hawaiensis: insight into snail gene family evolution.

    Science.gov (United States)

    Hannibal, Roberta L; Price, Alivia L; Parchem, Ronald J; Patel, Nipam H

    2012-05-01

    The transcriptional repressor snail was first discovered in Drosophila melanogaster, where it initially plays a role in gastrulation and mesoderm formation, and later plays a role in neurogenesis. Among arthropods, this role of snail appears to be conserved in the insects Tribolium and Anopheles gambiae, but not in the chelicerates Cupiennius salei and Achaearanea tepidariorum, the myriapod Glomeris marginata, or the Branchiopod crustacean Daphnia magna. These data imply that within arthropoda, snail acquired its role in gastrulation and mesoderm formation in the insect lineage. However, crustaceans are a diverse group with several major taxa, making analysis of more crustaceans necessary to potentially understand the ancestral role of snail in Pancrustacea (crustaceans + insects) and thus in the ancestor of insects as well. To address these questions, we examined the snail family in the Malacostracan crustacean Parhyale hawaiensis. We found three snail homologs, Ph-snail1, Ph-snail2 and Ph-snail3, and one scratch homolog, Ph-scratch. Parhyale snail genes are expressed after gastrulation, during germband formation and elongation. Ph-snail1, Ph-snail2, and Ph-snail3 are expressed in distinct patterns in the neuroectoderm. Ph-snail1 is the only Parhyale snail gene expressed in the mesoderm, where its expression cycles in the mesodermal stem cells, called mesoteloblasts. The mesoteloblasts go through a series of cycles, where each cycle is composed of a migration phase and a division phase. Ph-snail1 is expressed during the migration phase, but not during the division phase. We found that as each mesoteloblast division produces one segment's worth of mesoderm, Ph-snail1 expression is linked to both the cell cycle and the segmental production of mesoderm.

  13. Phenotypic plasticity in the common garden snail: big guts and heavier mucus glands compete in snails faced with the dual challenge of poor diet and coarse substrate.

    Science.gov (United States)

    Munn, Adam J; Treloar, Marguerite

    2016-12-26

    Phenotypic plasticity allows animals to manage environmental challenges. Studies aimed at quantifying plasticity often focus on one challenge, such as diet, and one organ system, such the gastrointestinal tract, but this approach may not adequately reflect how plasticity could buffer multiple challenges. Thus, we investigated the outcomes of a dual challenge experiment that fed land snails either a high-fibre (low quality) or a low-fibre (high quality) diet, and simultaneously exercised them daily over 1.2 m on either a smooth surface of polyvinyl chloride (PVC) or a rough sandpaper. By the end of 20 days, snails fed the poor quality diet had a longer crop and oesophagus and a heavier intestine and rectum than those offered a low-fibre diet. Additionally, high-fibre fed snails had a smaller spermoviduct and oviduct. When also exercised on sandpaper, high-fibre fed snails had a smaller digestive gland, a main energy store, than those exercised on PVC. All snails exercised on sandpaper had a heavier pedal mucus gland, used a loping gait and used less mucus than those on PVC plastic, but there was no difference in the average speed of snails on either surface, supporting the conclusion that loping is a mucus conserving gait. Notably, snails faced with both a diet and substrate challenge had a smaller kidney, which could directly effect fecundity. This demonstrates that our dual challenge approach has potential for evaluating the costs and limits of the plasticity necessary to fully appreciate the evolutionary significance of plasticity in snails and other species.

  14. Diversity and biogeography of land snails (Mollusca, Gastropoda) in the limestone hills of Perak, Peninsular Malaysia.

    Science.gov (United States)

    Foon, Junn Kitt; Clements, Gopalasamy Reuben; Liew, Thor-Seng

    2017-01-01

    Limestone hills are now gaining global conservation attention as hotspots for short-range endemic species. Levels of land snail endemism can be high at limestone hills, especially at hill clusters that are geographically isolated. In the State of Perak, Peninsular Malaysia, limestone hills have been opportunistically surveyed for land snails in the past, but the majority have yet to be surveyed. To address this knowledge gap, we systematically surveyed the terrestrial malacofauna of 12 limestone hills that, based on our opinion, are a representation of the limestone land snail assemblages within the State. Our inventory yielded high sampling completeness (>85%). We found 122 species of land snails, of which 34 species were unique to one of the surveyed hills. We identified 30 species that are potentially new to science. The number of land snail species recorded at each hill ranged between 39 and 63 species. Four of the sampled limestone hills namely, Prk 01 G. Tempurung, Prk 55 G. Pondok, Prk 47 Kanthan, and Prk 64 Bt Kepala Gajah, have high levels of species richness and unique species, representing 91% of the total species recorded in this study. We identified two clusters of limestone hills in central Perak with distinct differences in land snail species composition - a northern hill cluster on elevated granite bedrock and southern hill cluster in a low-lying valley surrounded by alluvial soils. As limestone hills continue to be quarried to meet the cement demand, the four identified limestone hills, along with other hills from the two clusters, warrant urgent conservation attention in order to maintain high species diversity within Perak's terrestrial malacofauna.

  15. Impact of cigarette butt leachate on tidepool snails.

    Science.gov (United States)

    Booth, David J; Gribben, Paul; Parkinson, Kerryn

    2015-06-15

    In urban areas, cigarette butts are the most common discarded refuse articles. In marine intertidal zones, they often fall into tidepools. We tested how common intertidal molluscs were affected by butt leachate in a laboratory experiment, where snails were exposed to various leachate concentrations. Mortality was very high, with all species showing 100% mortality at the full leachate concentration (5 butts per litre and 2h soak time) after 8days. However, Austrocochlea porcata showed higher mortality than the other 2 species at lower concentrations (10%, 25%) which may affect the relative abundance of the 3 snails under different concentrations of leachate pollution. Also, sublethal effects of leachate on snail activity were observed, with greater activity of Nerita atramentosa than the other 2 species at higher concentrations, suggesting it is more resilient than the other 2 species. While human health concerns predominate with respect to smoking, we show strong lethal and sublethal (via behavioural modifications) impacts of discarded butts on intertidal organisms, with even closely-related taxa responding differently.

  16. Predator-prey interactions between shell-boring beetle larvae and rock-dwelling land snails

    NARCIS (Netherlands)

    Baalbergen, Els; Helwerda, Renate; Schelfhorst, Rense; Castillo Cajas, Ruth F.; van Moorsel, Coline H. M.; Kundrata, Robin; Welter-Schultes, Francisco W.; Giokas, Sinos; Schilthuizen, Menno

    2014-01-01

    Drilus beetle larvae (Coleoptera: Elateridae) are specialized predators of land snails. Here, we describe various aspects of the predator-prey interactions between multiple Drilus species attacking multiple Albinaria (Gastropoda: Clausiliidae) species in Greece. We observe that Drilus species may be

  17. Heat shock proteins and survival strategies in congeneric land snails (Sphincterochila) from different habitats.

    Science.gov (United States)

    Mizrahi, Tal; Heller, Joseph; Goldenberg, Shoshana; Arad, Zeev

    2012-09-01

    Polmunate land snails are subject to stress conditions in their terrestrial habitat, and depend on a range of behavioural, physiological and biochemical adaptations for coping with problems of maintaining water, ionic and thermal balance. The involvement of the heat shock protein (HSP) machinery in land snails was demonstrated following short-term experimental aestivation and heat stress, suggesting that land snails use HSPs as part of their survival strategy. As climatic variation was found to be associated with HSP expression, we tested whether adaptation of land snails to different habitats affects HSP expression in two closely related Sphincterochila snail species, a desert species Sphincterochila zonata and a Mediterranean-type species Sphincterochila cariosa. Our study suggests that Sphincterochila species use HSPs as part of their survival strategy following desiccation and heat stress, and as part of the natural annual cycle of activity and aestivation. Our studies also indicate that adaptation to different habitats results in the development of distinct strategies of HSP expression in response to stress, namely the reduced expression of HSPs in the desert-inhabiting species. We suggest that these different strategies reflect the difference in heat and aridity encountered in the natural habitats, and that the desert species S. zonata relies on mechanisms and adaptations other than HSP induction thus avoiding the fitness consequences of continuous HSP upregulation.

  18. Comparative Functional Responses Predict the Invasiveness and Ecological Impacts of Alien Herbivorous Snails.

    Directory of Open Access Journals (Sweden)

    Meng Xu

    Full Text Available Understanding determinants of the invasiveness and ecological impacts of alien species is amongst the most sought-after and urgent research questions in ecology. Several studies have shown the value of comparing the functional responses (FRs of alien and native predators towards native prey, however, the technique is under-explored with herbivorous alien species and as a predictor of invasiveness as distinct from ecological impact. Here, in China, we conducted a mesocosm experiment to compare the FRs among three herbivorous snail species: the golden apple snail, Pomacea canaliculata, a highly invasive and high impact alien listed in "100 of the World's Worst Invasive Alien Species"; Planorbarius corneus, a non-invasive, low impact alien; and the Chinese native snail, Bellamya aeruginosa, when feeding on four locally occurring plant species. Further, by using a numerical response equation, we modelled the population dynamics of the snail consumers. For standard FR parameters, we found that the invasive and damaging alien snail had the highest "attack rates" a, shortest "handling times" h and also the highest estimated maximum feeding rates, 1/hT, whereas the native species had the lowest attack rates, longest handling times and lowest maximum feeding rates. The non-invasive, low impact alien species had consistently intermediate FR parameters. The invasive alien species had higher population growth potential than the native snail species, whilst that of the non-invasive alien species was intermediate. Thus, while the comparative FR approach has been proposed as a reliable method for predicting the ecological impacts of invasive predators, our results further suggest that comparative FRs could extend to predict the invasiveness and ecological impacts of alien herbivores and should be explored in other taxa and trophic groups to determine the general utility of the approach.

  19. Palatability and chemical defense of Phragmites australis to the marsh periwinkle snail Littoraria irrorata.

    Science.gov (United States)

    Hendricks, Lindsey G; Mossop, Hannah E; Kicklighter, Cynthia E

    2011-08-01

    Coastal marsh habitats are impacted by many disturbances, including habitat destruction, pollution, and the introduction of invasive species. The common reed, Phragmites australis, has been particularly invasive in the mesohaline regions of the Chesapeake Bay, but few studies have investigated its role in trophic interactions with North American marsh consumers. The marsh periwinkle snail Littoraria irrorata is a common grazer in marshes and grazes on the native grass Spartina alterniflora. Whether this snail grazes on Phragmites has not been addressed. We found Spartina leaves to be tougher than those of Phragmites, but despite this, snails consumed significantly more Spartina than Phragmites. Subsequent experiments demonstrated that Phragmites is chemically deterrent to snails by an unknown, moderately polar, compound. Further studies are required to more fully understand the interactions between Phragmites, herbivores, and Spartina, and how they may impact marsh ecosystems.

  20. Crab scars reveal survival advantage of left-handed snails

    OpenAIRE

    Dietl, Gregory P.; Hendricks, Jonathan R.

    2006-01-01

    Biological asymmetries are important elements of the structure and function of many living organisms. Using the Plio–Pleistocene fossil record of crab predation on morphologically similar pairs of right- and left-handed snail species, we show here for the first time, contrary to traditional wisdom, that rare left-handed coiling promotes survival from attacks by right-handed crabs. This frequency-dependent result influences the balance of selection processes that maintain left-handedness at th...

  1. MICROBIOLOGICAL AND CHEMICAL TESTING OF FOOD SNAILS MARKETEDS IN SARDINIA

    Directory of Open Access Journals (Sweden)

    T. Tedde

    2009-09-01

    Full Text Available A total of 29 samples of snails belonging to the species Helix aspersa, Helix aperta and Helix vermiculata were analysed for the presence of Salmonella spp. and Clostridium perfringens; Cadmium and Lead concentrations were determined by ICP-MS. One sample contained Salmonella sp.; Clostridium perfringens were not detected. The means of toxic metals (expressed as mg/Kg wet weight were the following: Cd 0,995, Pb 0,274. Key words

  2. Characterization of microsatellite loci for the littorine snail Bembicium vittatum.

    Science.gov (United States)

    Kennington, W J; Lukehurst, S S; Johnson, M S

    2008-11-01

    We describe the isolation and development of 17 polymorphic microsatellite loci for the intertidal snail Bembicium vittatum (Gastropoda: Littorinidae). The loci were tested in 46 individuals from a single population situated near the centre of the species distribution. No evidence of linkage disequilibrium was detected between any pair of loci. However, two loci showed significant departures from Hardy-Weinberg expectations. The number of alleles per locus ranged from two to 15. © 2008 The Authors. Journal compilation © 2008 Blackwell Publishing Ltd.

  3. Differences in predatory pressure on terrestrial snails by birds and mammals

    Indian Academy of Sciences (India)

    Zuzanna M Rosin; Paulina Olborska; Adrian Surmacki; Piotr Tryjanowski

    2011-09-01

    The evolution of shell polymorphism in terrestrial snails is a classic textbook example of the effect of natural selection in which avian and mammalian predation represents an important selective force on gene frequency. However, many questions about predation remain unclear, especially in the case of mammals. We collected 2000 specimens from eight terrestrial gastropod species to investigate the predation pressure exerted by birds and mice on snails. We found evidence of avian and mammalian predation in 26.5% and 36.8% of the shells. Both birds and mammals were selective with respect to snail species, size and morphs. Birds preferred the brown-lipped banded snail Cepaea nemoralis (L.) and mice preferred the burgundy snail Helix pomatia L. Mice avoided pink mid-banded C. nemoralis and preferred brown mid-banded morphs, which were neglected by birds. In contrast to mice, birds chose larger individuals. Significant differences in their predatory pressure can influence the evolution and maintenance of shell size and polymorphism of shell colouration in snails.

  4. Distribution of freshwater snails in the river Niger basin in Mali with special reference to the intermediate hosts of schistosomes

    DEFF Research Database (Denmark)

    Madsen, Henry; Coulibaly, Godefroy; Furu, Peter

    1987-01-01

    Snail surveys were carried out in various parts of Mali. All areas surveyed are part of the Niger basin being either affluents or irrigation schemes fed by this river. The snail species present varied greatly between areas. The following potential hosts of schistosomes were recorded: Biomphalaria...... pfeifferi, Bulinus truncatus, B. globosus, B. umbilicatus, B. forskalii and B. senegalensis. In the large irrigation schemes, i.e. 'Office du Niger' and Baguinéda, only B. pfeifferi and B. truncatus appear to be intermediate hosts. Snail distribution appeared to some extent to be focal and high snail...... densities appeared to be associated with human water contact activities, which apparently create favourable biotopes for the snails. This is probably due to an alteration of the vegetation and an increase of the trophic status of the site by contamination with food remnants and other debris. The larger...

  5. Snail1, Snail2, and E47 promote mammary epithelial branching morphogenesis

    OpenAIRE

    Lee, KangAe; Gjorevski, Nikolce; Boghaert, Eline; Radisky, Derek C.; Nelson, Celeste M.

    2011-01-01

    While the roles of Snail transcription factors in epithelial-mesenchymal transition (EMT) are well established, their functions in other morphogenetic processes are less understood. Here, Snail, Snail2, and E47 are shown to promote mammary gland branching morphogenesis, via activation of an EMT-like gene expression program.

  6. The Snail Takes a Walk with Me

    Institute of Scientific and Technical Information of China (English)

    王宜鸣; 乐伟国

    2008-01-01

    @@ 一、故事内容 I'm a snake. Today God gives me a job-I should take a walk with the snail. The snail moves too slowly. I have to scare him. He looks at me, full of shame. I am very angry. I pull him, and even kick.The snail cries, so he stops walking. I feel quite helpless.

  7. Snail modulates cell metabolism in MDCK cells

    Energy Technology Data Exchange (ETDEWEB)

    Haraguchi, Misako, E-mail: haraguci@m3.kufm.kagoshima-u.ac.jp [Department of Biochemistry and Molecular Biology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Indo, Hiroko P. [Department of Maxillofacial Radiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Iwasaki, Yasumasa [Health Care Center, Kochi University, Kochi 780-8520 (Japan); Iwashita, Yoichiro [Department of Maxillofacial Radiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Fukushige, Tomoko [Department of Dermatology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Majima, Hideyuki J. [Department of Maxillofacial Radiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Izumo, Kimiko; Horiuchi, Masahisa [Department of Environmental Medicine, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Kanekura, Takuro [Department of Dermatology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Furukawa, Tatsuhiko [Department of Molecular Oncology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan); Ozawa, Masayuki [Department of Biochemistry and Molecular Biology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima 890-8544 (Japan)

    2013-03-22

    Highlights: ► MDCK/snail cells were more sensitive to glucose deprivation than MDCK/neo cells. ► MDCK/snail cells had decreased oxidative phosphorylation, O{sub 2} consumption and ATP content. ► TCA cycle enzyme activity, but not expression, was lower in MDCK/snail cells. ► MDCK/snail cells showed reduced PDH activity and increased PDK1 expression. ► MDCK/snail cells showed reduced expression of GLS2 and ACLY. -- Abstract: Snail, a repressor of E-cadherin gene transcription, induces epithelial-to-mesenchymal transition and is involved in tumor progression. Snail also mediates resistance to cell death induced by serum depletion. By contrast, we observed that snail-expressing MDCK (MDCK/snail) cells undergo cell death at a higher rate than control (MDCK/neo) cells in low-glucose medium. Therefore, we investigated whether snail expression influences cell metabolism in MDCK cells. Although gylcolysis was not affected in MDCK/snail cells, they did exhibit reduced pyruvate dehydrogenase (PDH) activity, which controls pyruvate entry into the tricarboxylic acid (TCA) cycle. Indeed, the activity of multiple enzymes involved in the TCA cycle was decreased in MDCK/snail cells, including that of mitochondrial NADP{sup +}-dependent isocitrate dehydrogenase (IDH2), succinate dehydrogenase (SDH), and electron transport Complex II and Complex IV. Consequently, lower ATP content, lower oxygen consumption and increased survival under hypoxic conditions was also observed in MDCK/snail cells compared to MDCK/neo cells. In addition, the expression and promoter activity of pyruvate dehydrogenase kinase 1 (PDK1), which phosphorylates and inhibits the activity of PDH, was increased in MDCK/snail cells, while expression levels of glutaminase 2 (GLS2) and ATP-citrate lyase (ACLY), which are involved in glutaminolysis and fatty acid synthesis, were decreased in MDCK/snail cells. These results suggest that snail modulates cell metabolism by altering the expression and activity of

  8. Snail Hosts of Paragonimus in Asia and the Americas

    Institute of Scientific and Technical Information of China (English)

    G.M.DAVIS; CHENCui-E; 等

    1994-01-01

    We have undertaken a comprehensive review of snail hosts of Paragonimus world-wide exclusive of Africa based on modern malacological data,where available,and with consideration of the phylogeny of the snail groups involved.This is the first comprehensive review since those made by Chen(1979)and Chen et al.(1983),and there have been considerable taxonomic changes over the past decade. A number of names and concepts found in the medical malacological and parasitological literature up to the present time require revision or correction.There ae vast radiations of snails of the superfamilies Cerithiacea and Rissoacea involved in the transmission of Paragonimus in CHina.We list 54 species world-wide of which 35(65%)occur in China.Revisions and corrections pertaining to China include:(i)the family Hydrobiidae does not occur in China or S.E.Asia and thd Pomatiopsidae should be used,(ii)The genus Bythinella is entirely European(Hydrobiidae:Amnicolinae).The so-called Bythinella of China belongs to the genus Erhaia(Pomatiopsidae).(iii)The generic name Pseudobythinella described from China is preoccupied,a junior synonym of Pseudobythinella Melville 1956,a fossil from england,ll chinese Pseudobythinella are now classified as Erhaia.(iv)Akiyoshia has been used as a generic name for some snails in Hunan transmitting Paragonimus,Akiyoshia is from Japan and biological/ecological data indicate tat the Chinese taxon is not Akiyoshia.(v)The genus Tricula in recent Chinese literature is comprised of four genera determined by detailed comparative anatomical data:Tricula,Neotricula,Gammatricula,and Jinhongia Shells cannot be used to discriminate among them.(vi)tricula cristella has been consistently misidentified in collections in China and literature.However,genuine T.cristella does transmit Paragonimus skrjabini.(vii)Tricula minutoides in the Chinese literature has been misidentified,and specimens,are T.cristella.(viii)The genus Melania and the family Melaniidae are used in the

  9. Production of apple snail for space diet

    Science.gov (United States)

    Yamashita, Masamichi; Motoki, Shigeru; Space Agriculture Task Force, J.; Katayama, Naomi

    For food production in space at recycling bio-elements under closed environment, appropriate organisms should be chosen to drive the closed materials recycle loop. We propose a combination of green algae, photosynthetic protozoa, and aquatic plants such as Wolffia spp., for the primary producer fixing solar energy to chemical form in biomass, and apple snail, Pomacea bridgesii, which converts this biomass to animal meat. Because of high proliferation rate of green algae or protozoa compared to higher plants, and direct conversion of them to apple snail, the efficiency of food production in this combination is high, in terms of energy usage, space for rearing, and yield of edible biomass. Furthermore, green algae and apple snail can form a closed ecological system with exchanging bio-elements between two member, i.e. excreta of snail turn to fertilizer of algae, and grown algae become feed for snail. Since apple snail stays in water or on wet substrate, control of rearing is easy to make. Mass production technology of apple snail has been well established to utilize it as human food. Nutrients of apple snail are also listed in the standard tables of food composition in Japan. Nutrients for 100 g of apple snail canned in brine are energy 340 kJ, protein 16.5 g, lipid 1.0 g, cholesterol 240 mg, carbohydrate 0.8 g, Ca 400 mg, Fe 3.9 mg, Zn 1.5 mg. It is rich in minerals, especially Ca and Fe. Vitamin contents are quite low, but K 0.005 mg, B2 0.09 mg, B12 0.0006 mg, folate 0.001 mg, and E 0.6 mg. The amino acid score of apple snail could not be found in literature. Overall, apple snail provides rich protein and animal lipid such as cholesterol. It could be a good source of minerals. However, it does not give enough vitamin D and B12 , which are supposed to be supplemented by animal origin foods. In terms of acceptance in food culture, escargot is a gourmet menu in French dishes, and six to ten snail, roughly 50 g, are served for one person. Apple snail reaches to 30 g

  10. The potential utility of nested PCR for investigation ofCoxiella burnetii in Iranian snails

    Institute of Scientific and Technical Information of China (English)

    Mina Dehghani-Samani; Abbas Doosti; Asghar Arshi

    2016-01-01

    Objective: To detect the prevalence ofCoxiella burnetii (C. burnetii) in two species of snails consisted ofLymnaea palustris (L. palustris) andPomacea canaliculata (P. canaliculata) by using nestedPCR method in Chaharmahel Va Bakhtiari Province which is located in the southwest of Iran. Methods:A total of160 snail samples consisted of 100L. palustris and 60P. canaliculata were collected from 4 rice paddy fields in the southwest of Iran between June and August 2014. Snails'DNA was extracted by a genomicDNA purification kit according to the manufacturer's instructions. Detection of the presence ofC. burnetii'sDNA was carried out by using a nested PCR assay with [specific primers outer membrane protein 1 (OMP1)-OMP2 and OMP3-OMP4] targeting the com1 gene. Results: In this study, a total of 160 snail samples were tested and 15 (9.37%) samples were found positive forC. burnetii, 15 samples were positive from theL. palustris and there were no positive samples fromP. canaliculata. Conclusions: Snails are kind of gastropods which seem to be harmless in life, but these small gastropods can be very dangerous for farmers, especially in humid climates. Also,C. burnetii in snails showed that this bacterium can be a factor of transmission of contamination to human beings and animals.

  11. Are sick individuals weak competitors? Competitive ability of snails parasitized by a gigantism-inducing trematode.

    Science.gov (United States)

    Seppälä, Otto; Karvonen, Anssi; Kuosa, Marja; Haataja, Maarit; Jokela, Jukka

    2013-01-01

    Parasitized individuals are often expected to be poor competitors because they are weakened by infections. Many trematode species, however, although extensively exploiting their mollusc hosts, also induce gigantism (increased host size) by diverting host resources towards growth instead of reproduction. In such systems, alternatively to reduced competitive ability due to negative effects of parasitism on host performance, larger size could allow more efficient resource acquisition and thus increase the relative competitive ability of host individuals. We addressed this hypothesis by testing the effect of a trematode parasite Diplostomum pseudospathaceum on the competitive ability of its snail host Lymnaea stagnalis. We experimentally examined the growth of snails kept in pairs in relation to their infection status and intensity of resource competition (i.e. food availability). We found that parasitized snails grew faster and their reproduction was reduced compared to unparasitized individuals indicating parasite-induced gigantism. However, growth of the snails was faster when competing with parasitized individuals compared to unparasitized snails indicating reduced competitive ability due to parasitism. The latter effect, however, was relatively weak suggesting that the effects of the parasite on snail physiology may partly override each other in determining competitive ability.

  12. The potential utility of nested PCR for investigation of Coxiella burnetii in Iranian snails

    Directory of Open Access Journals (Sweden)

    Mina Dehghani-Samani

    2016-03-01

    Full Text Available Objective: To detect the prevalence of Coxiella burnetii (C. burnetii in two species of snails consisted of Lymnaea palustris (L. palustris and Pomacea canaliculata (P. canaliculata by using nested PCR method in Chaharmahel Va Bakhtiari Province which is located in the southwest of Iran. Methods: A total of 160 snail samples consisted of 100 L. palustris and 60 P. canaliculata were collected from 4 rice paddy fields in the southwest of Iran between June and August 2014. Snails' DNA was extracted by a genomic DNA purification kit according to the manufacturer's instructions. Detection of the presence of C. burnetii's DNA was carried out by using a nested PCR assay with [specific primers outer membrane protein 1 (OMP1-OMP2 and OMP3-OMP4] targeting the com1 gene. Results: In this study, a total of 160 snail samples were tested and 15 (9.37% samples were found positive for C. burnetii, 15 samples were positive from the L. palustris and there were no positive samples from P. canaliculata. Conclusions: Snails are kind of gastropods which seem to be harmless in life, but these small gastropods can be very dangerous for farmers, especially in humid climates. Also, C. burnetii in snails showed that this bacterium can be a factor of transmission of contamination to human beings and animals.

  13. Are sick individuals weak competitors? Competitive ability of snails parasitized by a gigantism-inducing trematode.

    Directory of Open Access Journals (Sweden)

    Otto Seppälä

    Full Text Available Parasitized individuals are often expected to be poor competitors because they are weakened by infections. Many trematode species, however, although extensively exploiting their mollusc hosts, also induce gigantism (increased host size by diverting host resources towards growth instead of reproduction. In such systems, alternatively to reduced competitive ability due to negative effects of parasitism on host performance, larger size could allow more efficient resource acquisition and thus increase the relative competitive ability of host individuals. We addressed this hypothesis by testing the effect of a trematode parasite Diplostomum pseudospathaceum on the competitive ability of its snail host Lymnaea stagnalis. We experimentally examined the growth of snails kept in pairs in relation to their infection status and intensity of resource competition (i.e. food availability. We found that parasitized snails grew faster and their reproduction was reduced compared to unparasitized individuals indicating parasite-induced gigantism. However, growth of the snails was faster when competing with parasitized individuals compared to unparasitized snails indicating reduced competitive ability due to parasitism. The latter effect, however, was relatively weak suggesting that the effects of the parasite on snail physiology may partly override each other in determining competitive ability.

  14. Structure of mega-hemocyanin reveals protein origami in snails.

    Science.gov (United States)

    Gatsogiannis, Christos; Hofnagel, Oliver; Markl, Jürgen; Raunser, Stefan

    2015-01-06

    Mega-hemocyanin is a 13.5 MDa oxygen transporter found in the hemolymph of some snails. Similar to typical gastropod hemocyanins, it is composed of 400 kDa building blocks but has additional 550 kDa subunits. Together, they form a large, completely filled cylinder. The structural basis for this highly complex protein packing is not known so far. Here, we report the electron cryomicroscopy (cryo-EM) structure of mega-hemocyanin complexes from two different snail species. The structures reveal that mega-hemocyanin is composed of flexible building blocks that differ in their conformation, but not in their primary structure. Like a protein origami, these flexible blocks are optimally packed, implementing different local symmetries and pseudosymmetries. A comparison between the two structures suggests a surprisingly simple evolutionary mechanism leading to these large oxygen transporters.

  15. Invasive snails and an emerging infectious disease: results from the first national survey on Angiostrongylus cantonensis in China.

    Directory of Open Access Journals (Sweden)

    Shan Lv

    Full Text Available BACKGROUND: Eosinophilic meningitis (angiostrongyliasis caused by Angiostrongylus cantonensis is emerging in mainland China. However, the distribution of A. cantonensis and its intermediate host snails, and the role of two invasive snail species in the emergence of angiostrongyliasis, are not well understood. METHODOLOGY/PRINCIPAL FINDINGS: A national survey pertaining to A. cantonensis was carried out using a grid sampling approach (spatial resolution: 40x40 km. One village per grid cell was randomly selected from a 5% random sample of grid cells located in areas where the presence of the intermediate host snail Pomacea canaliculata had been predicted based on a degree-day model. Potential intermediate hosts of A. cantonensis were collected in the field, restaurants, markets and snail farms, and examined for infection. The infection prevalence among intermediate host snails was estimated, and the prevalence of A. cantonensis within P. canaliculata was displayed on a map, and predicted for non-sampled locations. It was confirmed that P. canaliculata and Achatina fulica were the predominant intermediate hosts of A. cantonensis in China, and these snails were found to be well established in 11 and six provinces, respectively. Infected snails of either species were found in seven provinces, closely matching the endemic area of A. cantonensis. Infected snails were also found in markets and restaurants. Two clusters of A. cantonensis-infected P. canaliculata were predicted in Fujian and Guangxi provinces. CONCLUSIONS/SIGNIFICANCE: The first national survey in China revealed a wide distribution of A. cantonensis and two invasive snail species, indicating that a considerable number of people are at risk of angiostrongyliasis. Health education, rigorous food inspection and surveillance are all needed to prevent recurrent angiostrongyliasis outbreaks.

  16. An overview of freshwater snails in Asia with main focus on Vietnam.

    Science.gov (United States)

    Madsen, H; Hung, N M

    2014-12-01

    Freshwater snails have received much attention for their role as intermediate hosts for trematodes causing disease in people and animals such as schistosomiasis and various food-borne trematodes. While effective medical treatment exists for some of these diseases there is need for preventive measures to reduce transmission, e.g. control of intermediate hosts because transmission patterns are often complicated due to presence of reservoir final hosts. In order to implement control measures against the intermediate host snails with minimal impact on the freshwater ecosystems and their biodiversity, a profound knowledge on transmission patterns of the trematodes is required and this is partly related to distribution, habitat preferences, and seasonal variation in density of the intermediate host species. Identification of snail species can be problematic on the basis of morphological and anatomical characters alone as some species show morphological plasticity and similarly morphological differentiation of cercariae found in snails may be difficult and this could lead to biased perceptions of intermediate host spectra and transmission patterns. In this paper, we give an overview of the snail families and their medical and veterinary importance in Asia but with main focus on Vietnam.

  17. 77 FR 40375 - Receipt of Applications for Endangered Species Permits

    Science.gov (United States)

    2012-07-09

    ... species, 14 fish species, 34 fresh-water mussel species, 2 snail species, 1 insect species, and 2 plant... Ecology Center, Gainesville, Florida Applicant requests authorization to conduct scientific research on...

  18. Crab scars reveal survival advantage of left-handed snails.

    Science.gov (United States)

    Dietl, Gregory P; Hendricks, Jonathan R

    2006-09-22

    Biological asymmetries are important elements of the structure and function of many living organisms. Using the Plio-Pleistocene fossil record of crab predation on morphologically similar pairs of right- and left-handed snail species, we show here for the first time, contrary to traditional wisdom, that rare left-handed coiling promotes survival from attacks by right-handed crabs. This frequency-dependent result influences the balance of selection processes that maintain left-handedness at the species level and parallels some social interactions in human cultures, such as sports that involve dual contests between opponents of opposite handedness.

  19. Ribosomal DNA ITS-1 sequencing of Galba truncatula (Gastropoda, Lymnaeidae and its potential impact on fascioliasis transmission in Mendoza, Argentina

    Directory of Open Access Journals (Sweden)

    Bargues, M. D.

    2006-12-01

    Full Text Available Sequencing of the rDNA ITS–1 proved that the lymnaeid snail species Galba truncatula is present in Argentina and that it belongs to the haplotype HC, the same as that responsible for the fascioliasis transmission in the human hyperendemic area with the highest human prevalences and intensities known, the Northern Bolivian Altiplano.

  20. Toxicity of anti-fouling biocides to encysted metacercariae of Echinoparyphium recurvatum (Digenea: Echinostomatidae) and their snail hosts.

    Science.gov (United States)

    Morley, N J; Leung, K M Y; Morritt, D; Crane, M

    2004-07-01

    The toxicity of the anti-fouling biocides tributyltin (TBTO), copper, and Irgarol 1051 (irgarol) at a nominal concentration of 10 microg/l over a 30 day period were investigated against the viability of metacercarial cysts of the digenean parasite Echinoparyphium recurvatum resident within the body of two common freshwater snails, Lymnaea peregra and Physa fontinalis. Reduced parasite viability was found under most exposures in both snail species. However a greater effect of toxicant exposure was found in cysts within P. fontinalis compared to those in L. peregra. This was associated with an increased mortality of the host snail. Among all tested biocides, TBTO exposures induced the highest mortality to both the parasite and their hosts. These results suggest that parasite viability is interlinked with survival of the host snail. The mechanisms of differing toxicity between host species and its relevance to successful parasite transmission to the next host are discussed.

  1. Reproductive ecology of the giant African snail in South Florida

    DEFF Research Database (Denmark)

    Roda, Amy; Nachman, Gøsta Støger; Weihman, Scott

    2016-01-01

    Giant African snail (Achatina fulica (Bowdich, 1822)), an important invasive snail, was recently found in South Florida, USA. An extensive eradication effort was initiated consisting of pesticide applications, debris removal and hand collections. We studied the reproduction capacity and population...... dynamics of snails collected from 22 populations for two years to help evaluate the likely success of the eradication program. A total of 23,890 snails, ranging from 25-131 mm, were measured, dissected and the number of eggs in each snail counted. Gravid snails ranged from 48-128 mm. Only 5% of snails had...... eggs, which were found year round. As the snails increased in size, they were more likely to include reproducing individuals. However, the percentage of gravid snails peaked when snails were approximately 90 mm. Although more prevalent, small (

  2. Diversity increases biomass production for trematode parasites in snails

    Science.gov (United States)

    Hechinger, Ryan F.; Lafferty, Kevin D.; Kuris, Armand M.

    2008-01-01

    Increasing species diversity typically increases biomass in experimental assemblages. But there is uncertainty concerning the mechanisms of diversity effects and whether experimental findings are relevant to ecological process in nature. Hosts for parasites provide natural, discrete replicates of parasite assemblages. We considered how diversity affects standing-stock biomass for a highly interactive parasite guild: trematode parasitic castrators in snails. In 185 naturally occurring habitat replicates (individual hosts), diverse parasite assemblages had greater biomass than single-species assemblages, including those of their most productive species. Additionally, positive diversity effects strengthened as species segregated along a secondary niche axis (space). The most subordinate species—also the most productive when alone—altered the general positive effect, and was associated with negative diversity effects on biomass. These findings, on a previously unstudied consumer class, extend previous research to illustrate that functional diversity and species identity may generally both explain how diversity influences biomass production in natural assemblages of competing species.

  3. An overview of freshwater snails in Asia with main focus on Vietnam

    DEFF Research Database (Denmark)

    Madsen, Henry; Hung, N. M.

    2014-01-01

    Freshwater snails have received much attention for their role as intermediate hosts for trematodes causing disease in people and animals such as schistosomiasis and various food-borne trematodes. While effective medical treatment exists for some of these diseases there is need for preventive...... measures to reduce transmission, e.g. control of intermediate hosts because transmission patterns are often complicated due to presence of reservoir final hosts. In order to implement control measures against the intermediate host snails with minimal impact on the freshwater ecosystems...... and their biodiversity, a profound knowledge on transmission patterns of the trematodes is required and this is partly related to distribution, habitat preferences, and seasonal variation in density of the intermediate host species. Identification of snail species can be problematic on the basis of morphological...

  4. Rooks (Corvus frugilegus) dine on snails in Poland

    OpenAIRE

    MACIOROWSKI, Grzegorz; BURAL, Dobieslaw; GIERSZAL, Henryk; URBANSKA, Maria

    2014-01-01

    Evidence of breeding rooks feeding on Roman snails (Helix pomatia) and grove snails (Cepaea nemoralis) is presented. Shell dimensions of food remains and intact Roman snails collected in the study area were measured in order to estimate the size and shape of the snails collected by rooks in relation to the food available in the vicinity of the rookery. Smaller and rounder snail shells were collected by rooks than were available in the area around the colony, indicating that the rooks collecte...

  5. The role of spatial and temporal heterogeneity and competition in structuring trematode communities in the great pond snail, Lymnaea stagnalis (L.)

    Science.gov (United States)

    Soldánová, Miroslava; Kuris, Armand M.; Scholz, Tomáš; Lafferty, Kevin D.

    2012-01-01

    We assessed how spatial and temporal heterogeneity and competition structure larval trematode communities in the pulmonate snail Lymnaea stagnalis. To postulate a dominance hierarchy, mark-release-recapture was used to monitor replacements of trematode species within snails over time. In addition, we sampled the trematode community in snails in different ponds in 3 consecutive years. A total of 7,623 snails (10,382 capture events) was sampled in 7 fishponds in the Jindřichův Hradec and Třeboň areas in South Bohemia (Czech Republic) from August 2006 to October 2008. Overall, 39% of snails were infected by a community of 14 trematode species; 7% of snails were infected with more than 1 trematode species (constituting 16 double- and 4 triple-species combinations). Results of the null-model analyses suggested that spatial heterogeneity in recruitment among ponds isolated trematode species from each other, whereas seasonal pulses in recruitment increased species interactions in some ponds. Competitive exclusion among trematodes led to a rarity of multiple infections compared to null-model expectations. Competitive relationships among trematode species were hypothesized as a dominance hierarchy based on direct evidence of replacement and invasion and on indirect evidence. Seven top dominant species with putatively similar competitive abilities (6 rediae and 1 sporocyst species) reduced the prevalence of the other trematode species developing in sporocysts only.

  6. Asymmetry of mandibular dentition is associated with dietary specialization in snail-eating snakes

    Science.gov (United States)

    2017-01-01

    Background In vertebrates, the left-and-right pairs of homologous organs are generally present in equal numbers. A remarkable exception is snail-eating snakes in the family Pareidae: almost all the pareid snakes have much more teeth on the right mandible than on the left for functional specialization in feeding on the dextral majority of land snails. Because the only exceptional species with symmetric dentition has been regarded as a slug-eater, the extent of dietary specialization on slugs could shape the degree of the lateral asymmetry of mandibular dentition (dentition asymmetry) even among snail eaters. Methods To test this, I compared the morphology and behavior of two sympatric species of Taiwanese snail-eating snakes, Pareas atayal and P. formosensis. Results Specimens collected in the same locality showed that the dentition asymmetry of P. formosensis was significantly smaller than that of P. atayal. Congruent to its weak asymmetry, P. formosensis showed a strong preference of slugs to snails in the feeding experiment. Discussion The dietary specialization of P. formosensis on slugs would contribute to niche partitioning from the sympatric congener P. atayal. This study suggests that the diverse variation in the dentition asymmetry of pareid snakes is the result of their dietary specialization and divergence. PMID:28265502

  7. Development of the feline lungworms Aelurostrongylus abstrusus and Troglostrongylus brevior in Helix aspersa snails.

    Science.gov (United States)

    Giannelli, Alessio; Ramos, Rafael Antonio Nascimento; Annoscia, Giada; Di Cesare, Angela; Colella, Vito; Brianti, Emanuele; Dantas-Torres, Filipe; Mutafchiev, Yasen; Otranto, Domenico

    2014-04-01

    Aelurostrongylus abstrusus (Strongylida, Angiostrongylidae) and Troglostrongylus brevior (Strongylida, Crenosomatidae) are regarded as important lungworm species of domestic felids, with the latter considered an emerging threat in the Mediterranean region. The present study aimed to assess their concurrent development in the mollusc Helix aspersa (Pulmonata, Helicidae). Thirty snails were infested with 100 first-stage larvae (L1) of A. abstrusus and T. brevior, isolated from a naturally infested kitten. Larval development was checked by digesting five specimens at 2, 6 and 11 days post infestation. Larvae retrieved were morphologically described and their identification was confirmed by specific PCR and sequencing. All H. aspersa snails were positive for A. abstrusus and T. brevior, whose larval stages were simultaneously detected at each time point. In addition, snails were exposed to outdoor conditions and examined after overwintering, testing positive up to 120 days post infestation. Data herein presented suggest that A. abstrusus and T. brevior develop in H. aspersa snails and may eventually co-infest cats. Data on the morphology of both parasitic species in H. aspersa provide additional information on their development and identification, to better understand the population dynamics of these lungworms in receptive snails and paratenic hosts.

  8. Influence of water quality on zinc toxicity to the Florida apple snail (Pomacea paludosa) and sensitivity of freshwater snails to zinc.

    Science.gov (United States)

    Hoang, Tham C; Tong, Xin

    2015-03-01

    The present study characterized the influence of water-quality characteristics on zinc (Zn) toxicity to the Florida apple snail (Pomacea paludosa) and the sensitivity of freshwater snails to Zn. Standard 96-h renewal acute toxicity tests were conducted with Zn and juvenile P. paludosa under 3 conditions of pH and alkalinity, water hardness, and dissolved organic carbon (DOC). Median lethal effect concentrations (96-h LC50s), no-observed- effect concentrations, lowest-observed-effect concentrations, LC10s, and LC20s were determined for each test. The results showed that Zn toxicity to P. paludosa decreased linearly with increasing hardness, pH, and DOC. A multiple linear regression model based on pH, hardness, and DOC was able to explain 99% of the observed variability in LC50s. These results are useful for the development of a biotic ligand model (BLM) for P. paludosa and Zn. Zinc acute toxicity data were collected from the literature for 12 freshwater snail species in a wide range of water-quality characteristics for species sensitivity distribution analysis. The results showed that P. paludosa is the second most sensitive to Zn. The present study also suggested that aqueous ZnCO3 and ZnHCO3 (-) can be bioavailable to P. paludosa. Therefore, bioavailability models (e.g., BLM) should take these Zn species into consideration for bioavailability when applied to snails.

  9. Parasites reduce food web robustness because they are sensitive to secondary extinction as illustrated by an invasive estuarine snail

    Science.gov (United States)

    Lafferty, Kevin D.; Kuris, Armand M.

    2009-01-01

    A robust food web is one in which few secondary extinctions occur after removing species. We investigated how parasites affected the robustness of the Carpinteria Salt Marsh food web by conducting random species removals and a hypothetical, but plausible, species invasion. Parasites were much more likely than free-living species to suffer secondary extinctions following the removal of a free-living species from the food web. For this reason, the food web was less robust with the inclusion of parasites. Removal of the horn snail, Cerithidea californica, resulted in a disproportionate number of secondary parasite extinctions. The exotic Japanese mud snail, Batillaria attramentaria, is the ecological analogue of the native California horn snail and can completely replace it following invasion. Owing to the similarities between the two snail species, the invasion had no effect on predator–prey interactions. However, because the native snail is host for 17 host-specific parasites, and the invader is host to only one, comparison of a food web that includes parasites showed significant effects of invasion on the native community. The hypothetical invasion also significantly reduced the connectance of the web because the loss of 17 native trematode species eliminated many links.

  10. Release of lungworm larvae from snails in the environment: potential for alternative transmission pathways.

    Directory of Open Access Journals (Sweden)

    Alessio Giannelli

    2015-04-01

    indicate that A. abstrusus and T. brevior infective L3 are shed in the mucus of H. aspersa or in water where infected gastropods had died submerged. Both elimination pathways may represent alternative route(s of environmental contamination and source of the infection for these nematodes under field conditions and may significantly affect the epidemiology of feline lungworms. Considering that snails may act as intermediate hosts for other metastrongyloid species, the environmental contamination by mucus-released larvae is discussed in a broader context.

  11. Characterizations of cholinesterases in golden apple snail (Pomacea canaliculata).

    Science.gov (United States)

    Zou, Xiang-Hui; Xie, Heidi Qun-Hui; Zha, Guang-Cai; Chen, Vicky Ping; Sun, Yan-Jie; Zheng, Yu-Zhong; Tsim, Karl Wah-Keung; Dong, Tina Ting-Xia; Choi, Roy Chi-Yan; Luk, Wilson Kin-Wai

    2014-07-01

    Cholinesterases (ChEs) have been identified in vertebrates and invertebrates. Inhibition of ChE activity in invertebrates, such as bivalve molluscs, has been used to evaluate the exposure of organophosphates, carbamate pesticides, and heavy metals in the marine system. The golden apple snail (Pomacea canaliculata) is considered as one of the worst invasive alien species harmful to rice and other crops. The ChE(s) in this animal, which has been found recently, but poorly characterized thus far, could serve as biomarker(s) for environmental surveillance as well as a potential target for the pest control. In this study, the tissue distribution, substrate preference, sensitivity to ChE inhibitors, and molecular species of ChEs in P. canaliculata were investigated. It was found that the activities of both AChE and BChE were present in all test tissues. The intestine had the most abundant ChE activities. Both enzymes had fair activities in the head, kidney, and gills. The BChE activity was more sensitive to tetra-isopropylpyrophosphoramide (iso-OMPA) than the AChE. Only one BChE molecular species, 5.8S, was found in the intestine and head, whereas two AChE species, 5.8S and 11.6S, were found there. We propose that intestine ChEs of this snail may be potential biomarkers for manipulating pollutions.

  12. Opisthorchis viverrini infection in the snail and fish intermediate hosts in Central Vietnam.

    Science.gov (United States)

    Dao, Ha Thanh Thi; Dermauw, Veronique; Gabriël, Sarah; Suwannatrai, Apiporn; Tesana, Smarn; Nguyen, Giang Thanh Thi; Dorny, Pierre

    2017-02-24

    Opisthorchis viverrini, a carcinogenic fish borne fluke, requires freshwater snails and fish as intermediate hosts. Opisthorchiasis is endemic in parts of Southeast Asia, including Central and South Vietnam. In this region the transmission by intermediate hosts has received little attention. Therefore, freshwater snails and wild fish from Bau My Tho, an opisthorchiasis endemic area in Binh Dinh Province were collected for examination of O. viverrini cercariae and metacercariae, respectively. A total of 12,000 snails belonging to six families, of which 1616 Bithynia snails representing Bithynia siamensis goniomphalos and Bithynia funiculata; as well as 754 fish representing 12 species were examined. Shedding of O. viverrini cercariae was observed only in B. s. goniomphalos and B. funiculata, at infection rates of 0.86% and 0.14%, respectively. O. viverrini infection in Bithynia spp. was significantly associated with the habitat but not with the species and the shell size of Bithynia spp. O. viverrini metacercariae were found in 10 fish species representing both Cyprinidae and non-Cyprinidae families. The prevalence of O. viverrini infection in fish was significantly associated with species. Carassius auratus, a fish species commonly eaten raw, Rasbora aurotaenia and Puntius brevis had the highest prevalence of 74.0%, 55.8% and 31.6%, respectively. Sharing of the same snail and fish intermediate host species was found for O. viverrini and a O. viverrini duck-genotype that are sympatric in the study region. This study is the first to report on the intermediate host species of O. viverrini in Central Vietnam and indicates a high risk of acquiring opistorchiasis when eating raw fish dishes.

  13. Experimental quantification of long distance dispersal potential of aquatic snails in the gut of migratory birds.

    Directory of Open Access Journals (Sweden)

    Casper H A van Leeuwen

    Full Text Available Many plant seeds and invertebrates can survive passage through the digestive system of birds, which may lead to long distance dispersal (endozoochory in case of prolonged retention by moving vectors. Endozoochorous dispersal by waterbirds has nowadays been documented for many aquatic plant seeds, algae and dormant life stages of aquatic invertebrates. Anecdotal information indicates that endozoochory is also possible for fully functional, active aquatic organisms, a phenomenon that we here address experimentally using aquatic snails. We fed four species of aquatic snails to mallards (Anas platyrhynchos, and monitored snail retrieval and survival over time. One of the snail species tested was found to survive passage through the digestive tract of mallards as fully functional adults. Hydrobia (Peringia ulvae survived up to five hours in the digestive tract. This suggests a maximum potential transport distance of up to 300 km may be possible if these snails are taken by flying birds, although the actual dispersal distance greatly depends on additional factors such as the behavior of the vectors. We put forward that more organisms that acquired traits for survival in stochastic environments such as wetlands, but not specifically adapted for endozoochory, may be sufficiently equipped to successfully pass a bird's digestive system. This may be explained by a digestive trade-off in birds, which maximize their net energy intake rate rather than digestive efficiency, since higher efficiency comes with the cost of prolonged retention times and hence reduces food intake. The resulting lower digestive efficiency allows species like aquatic snails, and potentially other fully functional organisms without obvious dispersal adaptations, to be transported internally. Adopting this view, endozoochorous dispersal may be more common than up to now thought.

  14. 78 FR 24432 - Receipt of Applications for Endangered Species Permits

    Science.gov (United States)

    2013-04-25

    ..., tag, release) 56 freshwater mussel species, 5 snail species, 7 fish species, and 1 species of turtle... (Eretmochelys imbricata), leatherback (Dermochelys coriacea), green (Chelonia mydas), loggerhead (Caretta caretta), and olive ridley (Lepidochelys olivacea) sea turtles for veterinary treatment, release...

  15. Modelling spatial distribution of snails transmitting parasitic worms with importance to human and animal health and analysis of distributional changes in relation to climate

    Directory of Open Access Journals (Sweden)

    Ulrik B. Pedersen

    2014-05-01

    Full Text Available The environment, the on-going global climate change and the ecology of animal species determine the localisation of habitats and the geographical distribution of the various species in nature. The aim of this study was to explore the effects of such changes on snail species not only of interest to naturalists but also of importance to human and animal health. The spatial distribution of freshwater snail intermediate hosts involved in the transmission of schistosomiasis, fascioliasis and paramphistomiasis (i.e. Bulinus globosus, Biomphalaria pfeifferi and Lymnaea natalensis were modelled by the use of a maximum entropy algorithm (Maxent. Two snail observation datasets from Zimbabwe, from 1988 and 2012, were com- pared in terms of geospatial distribution and potential distributional change over this 24-year period investigated. Climate data, from the two years were identified and used in a species distribution modelling framework to produce maps of pre- dicted suitable snail habitats. Having both climate- and snail observation data spaced 24 years in time represent a unique opportunity to evaluate biological response of snails to changes in climate variables. The study shows that snail habitat suit- ability is highly variable in Zimbabwe with foci mainly in the central Highveld but also in areas to the South and West. It is further demonstrated that the spatial distribution of suitable habitats changes with variation in the climatic conditions, and that this parallels that of the predicted climate change.

  16. Status report on Fish Springs pond snail

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report provides a life history of the pond snail (Lymnaea Hinkleyia pilsbryi) at Fish Springs National Wildlife Refuge. The following information is included;...

  17. CRCP-Prey choice of corallivorous snails

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The snail, Coralliophila abbreviata, is a common generalist corallivore and can be a major contributor to Caribbean acroporid tissue mortality. Considering the...

  18. Types of trematodes infecting freshwater snails found in irrigation canals in the East Nile locality, Khartoum, Sudan

    DEFF Research Database (Denmark)

    Mohammed, Nidal A. I.; Madsen, Henry; Ahmed, Abdel Aziz A. R. M.

    2016-01-01

    Background: The planorbid freshwater snails of the two genera, Biomphalaria and Bulinus -have been vigorously studied due to the role they play as intermediate hosts of schistosomiasis. In Sudan specifically, most studies have focused on the chemical and ecological control of the two genera......, but few studies have looked at their biological control. This study explored the coexistence of other species of freshwater snails and the two genera along with their trematode infections in relation to a number of environmental factors in the East Nile locality, Khartoum state, Sudan. Methods: Freshwater...... snails from irrigation canals (abueshreens) were sampled monthly from January 2004 to December 2005. The snails were examined for trematode infections by cercarial emergence immediately after collection and then weekly for an additional four weeks to allow for the maturation of prepatent infections...

  19. Haemolymph Components of Infected & None Infected Lymnaea Snails with Xiphidiocercariae

    Directory of Open Access Journals (Sweden)

    AA Saboor Yaraghi

    2011-03-01

    Full Text Available Background: In this study the haemolymph components of infected and none infected Lymnaea gedrosiana with xiphidiocercaria larvae was compared.Methods: Five hundred Fifty Lymnaea snails were collected from Ilam and Mazandaran prov­inces, Iran, during 2008-2009. The snails were transported to the lab at Tehran University of Medi­cal Sciences and their cercarial sheddings were studied. Haemolmyphs of snails were ex­tracted and cells were counted using haemocytometer and cell-surface carbohydrate were recog­nized by conjugated lectin (Lentil. Haemolymph protein concentrations were measured by Brad­ford protein assay method and soluble protein compositions were determined on sodium dodecyl sulphate polyacrilamide gel electrophoresis (SDS-PAGE.Result: From the 550 examined Lymnaea snails for cercariae, 27 snails were infected with xiphidiocer­cariae. Mean of haemolymph cells (haemocyte number were obtained 93480±2.43 (cells/ml for none infected snails (25 snail and 124560±2800 (cells/ml for infected snails (25 snail. Mannose carbohydrate was recognized on haemocyte of none infected and infected snails. Mean of protein concentration of haemolymph plasma was obtained as 1354 ± 160 μg/ml (1.4 mg/ml for none infected snails (25 snails and 1802±138 μg/ml (1.8 mg/ml for infected snail (25 snails. Comparing to none infected snails, the SDS-PAGE results of haemolymph plasma of infected snails, showed an extra protein band (70 kDa. The results showed a significant differ­ence between the amounts and the kinds of proteins in haemolymph of infected and none infected snails.Conclusion: This information might be useful to understand of parasite detection, adhesion, engulf­ment and antigen agglutination by snail.

  20. Ecological Speciation and the Intertidal Snail Littorina saxatilis

    Directory of Open Access Journals (Sweden)

    Juan Galindo

    2014-01-01

    Full Text Available In recent decades biologists studying speciation have come to consider that the process does not necessarily require the presence of a geographical barrier. Rather, it now seems to be possible for reproductive barriers to evolve within what was hitherto a single ‘‘species.’’ The intertidal snail Littorina saxatilis has been the focus of a considerable amount of work in this context, and it is now thought of as a good case study of ‘‘ecological speciation.’’ We review some of this work and briefly consider prospects for future developments.

  1. An octopaminergic system in the CNS of the snails, Lymnaea stagnalis and Helix pomatia

    OpenAIRE

    1998-01-01

    Octopamine (OA) levels in each ganglion of the terrestrial snail, Helix pomatia, and the pond snail, Lymnaea stagnalis, were measured by using the HPLC technique. In both species an inhomogeneous distribution of OA was found in the central nervous system. The buccal ganglia contained a concentration of OA (12.6 pmol mg-1 and 18.8 pmol mg-1) that was two to three times higher than the pedal (4.93 pmol mg-1 and 9.2 pmol mg-1) or cerebral (4.46 pmol mg-1 and 4.9 pmol mg-1) ganglia of Helix and L...

  2. Effects of Bt-maize material on the life cycle of the land snail Cantareus aspersus

    DEFF Research Database (Denmark)

    Kramarz, Paulina; de Vaufleury, Annette; Gimbert, Frédéric

    2009-01-01

    Insect resistant Bt-maize (MON 810) expresses active Cry1Ab endotoxin derived from Bacillus thuringiensis (Bt). Snails constitute non-target soil species potentially exposed to Bt-toxin through consumption of plant material and soil in fields where transgenic plants have been grown. We studied...... the effect of the Cry1Ab toxin on survival, growth and egg hatchability of the snail Cantareus aspersus. From the age of 4 to 88 weeks, snails were fed either powdered Bt-maize or non-Bt-maize and exposed to soil samples collected after harvesting either the Bt-maize or non-Bt-maize. We applied four...... treatments: non-Bt soil + non-Bt-maize (MM); Bt soil + Bt-maize (BB), non-Bt soil + Bt-maize (MB), Bt soil + non-Bt-maize (BM). Eggs laid by snails not exposed to Bt-toxin were also exposed to the two types of soils (Bt and non-Bt soil). At the end of growth (47 weeks of exposure), snails exposed to Bt...

  3. Imidacloprid induced alterations in enzyme activities and energy reserves of the land snail, Helix aspersa.

    Science.gov (United States)

    Radwan, M A; Mohamed, M S

    2013-09-01

    The in vivo sublethal toxic effects (0.2 and 0.6 LD50) of topically applied imidacloprid on biochemical biomarkers in the land snail, Helix aspersa was examined. Biochemical perturbations were assessed by measuring the three enzymatic (Acetylcholinesterase, AChE; catalase, CAT and glutathione-S-transferase, GST) activities and three energy reserves (protein, glycogen and lipids) in the snails. Snail samples were taken from each sublethal dose and control groups at 1, 3 and 7 days after treatment. The results revealed that there were overall decrease in AChE activity as well as depletion of lipids and glycogen contents in the imidacloprid-treated snails compared to control groups. The CAT and GST activities of treated snails with the sublethal doses of imidacloprid were significantly higher than those of untreated controls along the three times of exposure. Moreover, an increase in the level of total proteins was observed in animals treated with 0.6 LD50 imidacloprid compared to control groups. The alterations in all tested biochemical perturbations were most pronounced with the 0.6 LD50 than 0.2 LD50. This study suggests that alterations of the enzyme activities and energy reserves in this species that could be useful as biomarkers of imidacloprid exposure in the evaluation of terrestrial impacts of this insecticide.

  4. Specialized insulin is used for chemical warfare by fish-hunting cone snails.

    Science.gov (United States)

    Safavi-Hemami, Helena; Gajewiak, Joanna; Karanth, Santhosh; Robinson, Samuel D; Ueberheide, Beatrix; Douglass, Adam D; Schlegel, Amnon; Imperial, Julita S; Watkins, Maren; Bandyopadhyay, Pradip K; Yandell, Mark; Li, Qing; Purcell, Anthony W; Norton, Raymond S; Ellgaard, Lars; Olivera, Baldomero M

    2015-02-10

    More than 100 species of venomous cone snails (genus Conus) are highly effective predators of fish. The vast majority of venom components identified and functionally characterized to date are neurotoxins specifically targeted to receptors, ion channels, and transporters in the nervous system of prey, predators, or competitors. Here we describe a venom component targeting energy metabolism, a radically different mechanism. Two fish-hunting cone snails, Conus geographus and Conus tulipa, have evolved specialized insulins that are expressed as major components of their venoms. These insulins are distinctive in having much greater similarity to fish insulins than to the molluscan hormone and are unique in that posttranslational modifications characteristic of conotoxins (hydroxyproline, γ-carboxyglutamate) are present. When injected into fish, the venom insulin elicits hypoglycemic shock, a condition characterized by dangerously low blood glucose. Our evidence suggests that insulin is specifically used as a weapon for prey capture by a subset of fish-hunting cone snails that use a net strategy to capture prey. Insulin appears to be a component of the nirvana cabal, a toxin combination in these venoms that is released into the water to disorient schools of small fish, making them easier to engulf with the snail's distended false mouth, which functions as a net. If an entire school of fish simultaneously experiences hypoglycemic shock, this should directly facilitate capture by the predatory snail.

  5. Fascioliasis Control: In Vivo and In Vitro Phytotherapy of Vector Snail to Kill Fasciola Larva

    Science.gov (United States)

    Sunita, Kumari; Singh, D. K.

    2011-01-01

    Snail is one of the important components of an aquatic ecosystem, it acts as intermediate host of Fasciola species. Control of snail population below a certain threshold level is one of the important methods in the campaign to reduce the incidence of fascioliasis. Life cycle of the parasite can be interrupted by killing the snail or Fasciola larva redia and cercaria in the snail body. In vivo and in vitro toxicity of the plant products and their active component such as citral, ferulic acid, umbelliferone, azadirachtin, and allicin against larva of Fasciola in infected snail Lymnaea acuminata were tested. Mortality of larvae were observed at 2 h, 4 h, 6 h, and 8 h, of treatment. In in vivo treatment, azadirachtin caused highest mortality in redia and cercaria larva (8 h, LC50 0.11, and 0.05 mg/L) whereas in in vitro condition allicin was highly toxic against redia and cercaria (8 h, LC50 0.01, and 0.009 mg/L). Toxicity of citral was lowest against redia and cercaria larva. PMID:22132306

  6. Fascioliasis Control: In Vivo and In Vitro Phytotherapy of Vector Snail to Kill Fasciola Larva

    Directory of Open Access Journals (Sweden)

    Kumari Sunita

    2011-01-01

    Full Text Available Snail is one of the important components of an aquatic ecosystem, it acts as intermediate host of Fasciola species. Control of snail population below a certain threshold level is one of the important methods in the campaign to reduce the incidence of fascioliasis. Life cycle of the parasite can be interrupted by killing the snail or Fasciola larva redia and cercaria in the snail body. In vivo and in vitro toxicity of the plant products and their active component such as citral, ferulic acid, umbelliferone, azadirachtin, and allicin against larva of Fasciola in infected snail Lymnaea acuminata were tested. Mortality of larvae were observed at 2 h, 4 h, 6 h, and 8 h, of treatment. In in vivo treatment, azadirachtin caused highest mortality in redia and cercaria larva (8 h, LC50 0.11, and 0.05 mg/L whereas in in vitro condition allicin was highly toxic against redia and cercaria (8 h, LC50 0.01, and 0.009 mg/L. Toxicity of citral was lowest against redia and cercaria larva.

  7. Uptake and distribution of copper sulfate and its effect on the respiration rate of the hemocyanin-producing freshwater snail Lymnaea natalensis

    Energy Technology Data Exchange (ETDEWEB)

    Wolmarans, C.T.; Yssel, E.

    1988-08-01

    Copper sulfate was one of the earliest compounds suggested as a molluscicide and although several new compounds have since been developed, copper sulfate is still widely used against freshwater snail intermediate hosts of trematode parasites causing bilharzia. However, the toxic effect that copper sulfate may have on these species has not yet been investigated adequately. This incomplete picture of the action of copper sulfate on freshwater snails is further complicated by the fact that some of these snail species have hemocyanin (a protein containing copper) as respiration pigment. Because of the existence of a copper metabolic pathway, these species may handle external copper differently from those species with hemoglobin as respiration pigment. In the present study, the uptake of external copper in the form of copper sulfate, as well as the effect of this ion on respiration rate, was investigated in Lymnaea natalensis, the intermediate host of Fasciola gigantica. This snail possesses hemocyanin as respiratory pigment.

  8. The role of Snail in prostate cancer

    Science.gov (United States)

    Smith, Bethany N.; Odero-Marah, Valerie A.

    2012-01-01

    Prostate cancer is the second most frequently diagnosed cancer and the sixth leading cause of death from cancer in men. Epithelial-mesenchymal transition (EMT) is a process by which cancer cells invade and migrate, and is characterized by loss of cell-cell adhesion molecules such as E-cadherin and increased expression of mesenchymal proteins such as vimentin; EMT is also associated with resistance to therapy. Snail, a master regulator of EMT, has been extensively studied and reported in cancers such as breast and colon; however, its role in prostate cancer is not as widely reported. The purpose of this review is to put together recent facts that summarize Snail signaling in human prostate cancer. Snail is overexpressed in prostate cancer and its expression and activity is controlled via phosphorylation and growth factor signaling. Snail is involved in its canonical role of inducing EMT in prostate cancer cells; however, it plays a role in non-canonical pathways that do not involve EMT such regulation of bone turnover and neuroendocrine differentiation. Thus, studies indicate that Snail signaling contributes to prostate cancer progression and metastasis and therapeutic targeting of Snail in prostate cancer holds promise in �future. PMID:23076049

  9. Epigenetic regulation of EMT: the Snail story.

    Science.gov (United States)

    Lin, Yiwei; Dong, Chenfang; Zhou, Binhua P

    2014-01-01

    While the epithelial-mesenchymal transition (EMT) plays a fundamental role during development, its deregulation can adversely promote tumor metastasis. The phenotypic and cellular plasticity of EMT indicates that it is subject to epigenetic regulation. A hallmark of EMT is E-cadherin suppression. In this review, we try to embrace recent findings on the transcription factor Snail-mediated epigenetic silencing of E-cadherin. Our studies as well as those of others independently demonstrated that Snail can recruit various epigenetic machineries to the E-cadherin promoter. Based on these results, we propose a model of epigenetic regulation of EMT governed by Snail. Briefly, recruitment of the LSD1/HDAC complex by Snail facilitates histone H3K4 demethylation and H3/H4 deacetylation. Histone deacetylation may promote subsequent recruitment of PRC2 to methylate H3K27, while H3K4 demethylation favors the association of H3K9 methyltransferases G9a and Suv39H1. Finally, DNA methyltransferases (DNMTs) can be recruited to the promoter area in a G9a/Suv39H1-dependent manner. Together, these chromatin-modifying enzymes function in a Snail-mediated, highly orchestrated fashion to suppress E-cadherin. Disruption of the connection between Snail and these epigenetic machineries may represent an efficient strategy for the treatment of EMT-related diseases, including tumor metastasis.

  10. Behavioural responses of the snail Lymnaea acuminata to carbohydrates in snail-attractant pellets

    Science.gov (United States)

    Tiwari, Farindra; Singh, D. K.

    Snail control is one of the most important tools in the campaign to reduce the incidence of fascioliasis. In order to attain this objective, the method of bait formulation in order to contain an attractant and a molluscicide is an expedient approach to lure the target snail population to the molluscicide. This study identifies certain carbohydrates, namely sucrose, maltose, glucose, fructose and starch, for preparing such baits. These were tested on Lymnaea acuminata, an intermediate host of the digenean trematodes Fasciola hepatica and Fasciola gigantica. The behavioural responses of snails to these carbohydrates were examined. Significant variations in behavioural responses were observed in the snail even when the five carbohydrates were used in low concentrations in snail-attractant pellets. Starch emerged as the strongest attractant for Lymnaea acuminata, followed by maltose.

  11. New narrow-range endemic land snails from the sky islands of northern South Africa (Gastropoda: Streptaxidae and Urocyclidae

    Directory of Open Access Journals (Sweden)

    David G. Herbert

    2016-10-01

    Full Text Available One new genus and five new species of land snails are described from high altitude, insular, Afrotemperate forest habitats in northern South Africa. The distribution of these species is discussed in relation to other narrowly endemic land snails occurring in this and neighbouring regions. The new genus is Ptilototheca gen. nov.; the five new species are: Gulella davisae sp. nov., G. hadroglossa sp. nov., Ptilototheca soutpansbergensis gen. et sp. nov., Sheldonia monsmaripi sp. nov. and S. wolkbergensis sp. nov.

  12. Genetic variability and identification of the intermediate snail hosts of Schistosoma mansoni

    Directory of Open Access Journals (Sweden)

    Teofânia HDA Vidigal

    1998-01-01

    Full Text Available Studies based on shell or reproductive organ morphology and genetic considerations suggest extensive intraspecific variation in Biomphalaria snails. The high variability at the morphological and genetic levels, as well as the small size of some specimens and similarities between species complicate the correct identification of these snails. Here we review our work using methods based on polymerase chain reaction (PCR amplification for analysis of genetic variation and identification of Biomphalaria snails from Brazil, Argentina, Uruguay and Paraguay. Arbitrarily primed-PCR revealed that the genome of B. glabrata exihibits a remarkable degree of intraespecific polymorphism. Low stringency-PCR using primers for 18S rRNA permited the identification of B. glabrata, B. tenagophila and B. occidentalis. The study of individuals obtained from geographically distinct populations exhibits significant intraspecific DNA polymorphism, however specimens from the same species, exhibit some species specific LSPs. We also showed that PCR-restriction fragment of length polymorphism of the internal transcribed spacer region of Biomphalaria rDNA, using DdeI permits the differentiation of the three intermediate hosts of Schistosoma mansoni. The molecular biological techniques used in our studies are very useful for the generation of new knowledge concerning the systematics and population genetics of Biomphalaria snails.

  13. Socio-Economic Characteristics Of Snail Farmers, Consumers And ...

    African Journals Online (AJOL)

    A multi-stage sampling technique was employed to obtain a representative sample of ... between snail farmers' demographic characteristic and their production levels was ... only seven out of the twelve factors listed as limiting snail marketing.

  14. Microbiological and chemical analysis of land snails commercialised in Sicily

    Directory of Open Access Journals (Sweden)

    Antonello Cicero

    2015-05-01

    Full Text Available In this study 160 samples of snails belonging to the species Helix aspersa maxima and Helix aspersa muller were examined for chemical and microbiological analysis. Samples came from Greece and Poland. Results showed mean concentration of cadmium (0.35±0.036 mg/kg and lead (0.05±0.013 mg/kg much higher than the limit of detection. Mercury levels in both species were not detected. Microbiological analysis revealed the absence of Salmonella spp. and Clostridium spp. in both examined species. E. coli and K. oxytoca were observed in Helix aspersa maxima and Helix aspersa muller. Furthermore, one case of fungi positivity in samples of Helix aspersa muller was found. The reported investigations highlight the need to create and adopt a reference legislation to protect the health of consumers.

  15. Toxic effect and bioavailability of malathion spiked in natural sediments from the Ignacio Ramirez Dam on the snail Stagnicola sp.

    Science.gov (United States)

    Martínez-Tabche, Laura; Galar, M Marcela; Olvera, H Elena; Chehue, R Alejandro; López López, Eugenia; Gómez-Oliván, Leobardo; Terron Sierra, Oscar

    2002-07-01

    Malathion (MA) is a widely used insecticide in México. The snail Stagnicola sp is a native species of the Ignacio Ramírez dam (IRD). This work aimed to evaluate the bioavailability and toxicity of MA in sediments of the IRD from the Stagnicola sp snail, taking into account the physicochemical properties of the IRD sediment. The toxic effect of MA on the snail Stagnicola sp was evaluated by biochemical tests of acetylcholinesterase (AchE) activity, protein concentration, lipid peroxidation level (LPL), and lipid content; a toxicokinetic study was also carried out. An increment in all biochemical parameters was observed at the beginning of exposure, while at 48 and 72 h a decrement in AchE activity, LPL, and lipid content was observed. The kinetics study showed gradual uptake and rapid elimination of the insecticide in the test organism. The bioconcentration factor and the absorption and elimination constants led to the conclusion that this compound is not being stored in snails. However, at the end of the experiment, the snails without MA exhibited a lack of recovery in AchE activity, which indicates that there is no correlation between the inhibitory pattern of AchE activity and snail MA concentration.

  16. Studies on the Edible Terrestrial Snails Helix aspersa Muller Food Conversion Ratio in a Confined Microclimate System

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    Adrian Toader-Williams

    2010-05-01

    Full Text Available Terrestrial edible snail breeding is an agricultural activity that finds itself at pioneering stage in Romania. One of the species used in snail farming is Helix aspersa Muller. In order to accelerate their growth, farmers feed the snails with pumpkins as well as concentrated forage consisting of mix of flours to which calcium carbonate is added in order to supplement snails need for shell’s development. In a controlled microclimate environment we measured the average growth of six weeks old Helix aspersa Muller snails placed in four different plastic enclosures. The consumption of different type of foods within 24 hours period was measured. The wheat (60%, corn flour (20% and calcium carbonate (20% mix had a superior food conversion ratio (FCR of 4.80, whereas the second FCR registered 6.04 in the case of 53% pumpkin and 47% flour mix served in the same time followed by the pure fresh vegetable mix accounting for a FCR of 8.00 and by 19.02 when only the pumpkin has been administrated as meal. During the experiments the snails did not have access to soil, being known that soil is an integral part of their diet.

  17. Reproduction and demography of the Florida Everglade (Snail) Kite

    Science.gov (United States)

    Snyder, N.F.R.; Beissinger, S.R.; Chandler, R.E.

    1989-01-01

    An 18-year study of reproduction and survival of the Florida Everglade (Snail) Kite (Rostrhamus sociabilis plumbeus) has revealed the following: extremely poor nesting success (only 13.6% of nests found at the nest-building stage successful); extremely long breeding seasons (some reproductive activity in almost all months in good years); frequent multiple brooding and frequent multiple brooding and frequent renesting after failure; low egg hatchability (81%); high failure rates due to nest collapse, desertion, and predation; extremely high survival of juveniles and adults under good water conditions; and high vulnerability to drought due to near total dependency on a single species of drought-sensitive snail for food. Despite low nesting success, the species has increased rapidly under good conditions, mainly because of multiple nesting attempts within long breeding seasons and high survival rates of free-flying birds. Nesting success varied significantly between regions and nest substrates, but not as a function of seasons or solitary vs. colonial nesting. While nesting success was reduced in low water years, this effect was at least partly due to heavy use of poor nest substrates under such conditions. Clutch size and numbers of young per successful nest varied with regions, but not as a function of seasons or water levels. The effects of coloniality on clutch size and numbers of young were inconsistent. Significant effects of nest-substrate types on clutch size and numbers of young were apparently artifacts of substrate differences between regions.

  18. Salinity adaptation of the invasive New Zealand mud snail (Potamopyrgus antipodarum) in the Columbia River estuary (Pacific Northwest, USA): Physiological and molecular studies

    Science.gov (United States)

    Hoy, Marshal; Boese, Bruce L.; Taylor, Louise; Reusser, Deborah; Rodriguez, Rusty

    2012-01-01

    In this study, we examine salinity stress tolerances of two populations of the invasive species New Zealand mud snail Potamopyrgus antipodarum, one population from a high salinity environment in the Columbia River estuary and the other from a fresh water lake. In 1996, New Zealand mud snails were discovered in the tidal reaches of the Columbia River estuary that is routinely exposed to salinity at near full seawater concentrations. In contrast, in their native habitat and throughout its spread in the western US, New Zealand mud snails are found only in fresh water ecosystems. Our aim was to determine whether the Columbia River snails have become salt water adapted. Using a modification of the standard amphipod sediment toxicity test, salinity tolerance was tested using a range of concentrations up to undiluted seawater, and the snails were sampled for mortality at daily time points. Our results show that the Columbia River snails were more tolerant of acute salinity stress with the LC50 values averaging 38 and 22 Practical Salinity Units for the Columbia River and freshwater snails, respectively. DNA sequence analysis and morphological comparisons of individuals representing each population indicate that they were all P. antipodarum. These results suggest that this species is salt water adaptable and in addition, this investigation helps elucidate the potential of this aquatic invasive organism to adapt to adverse environmental conditions.

  19. Characterization of South American Snails of the Genus Biomphalaria (Basommatophora: Planorbidae) and Schistosoma mansoni (Platyhelminthes: Trematoda) in Molluscs by PCR-RFLP

    Science.gov (United States)

    Teodoro, Tatiana Maria; Jannotti-Passos, Liana Konovaloff; Lira-Moreira, Pollanah M.; Goveia, Christiane De Oliveira; Carvalho, Omar dos Santos

    2016-01-01

    The identification of snails of the genus Biomphalaria can be done using morphological characteristics which depends on the size of the snails and skill and knowledge of researcher. These methods sometimes are not adequate for identification of species. The PCR-RFLP, using the ITS region of the rDNA, has been used to identify Brazilian species of the genus Biomphalaria. Nevertheless, there is a lack of information about snails from other Latin American countries. In addition, some snails may be infected by Schistosoma mansoni and when submitted to PCR-RFLP they show molecular profiles different from those previously standardized for the other mollusc species. In this work the molecular profiles of 15 species and the subspecies were established by PCR-RFLP of ITS-rDNA with the enzyme DdeI. Moreover, the molecular profiles of host species, B. glabrata, B. straminea, B. tenagophila, and B. prona, infected by S. mansoni were also established. The molluscs were dissected to permit morphological identification. These results contribute to a correct identification of snails of the genus Biomphalaria and detection of these snails infected by S. mansoni. PMID:27981045

  20. Characterization of South American Snails of the Genus Biomphalaria (Basommatophora: Planorbidae and Schistosoma mansoni (Platyhelminthes: Trematoda in Molluscs by PCR-RFLP

    Directory of Open Access Journals (Sweden)

    Roberta Lima Caldeira

    2016-01-01

    Full Text Available The identification of snails of the genus Biomphalaria can be done using morphological characteristics which depends on the size of the snails and skill and knowledge of researcher. These methods sometimes are not adequate for identification of species. The PCR-RFLP, using the ITS region of the rDNA, has been used to identify Brazilian species of the genus Biomphalaria. Nevertheless, there is a lack of information about snails from other Latin American countries. In addition, some snails may be infected by Schistosoma mansoni and when submitted to PCR-RFLP they show molecular profiles different from those previously standardized for the other mollusc species. In this work the molecular profiles of 15 species and the subspecies were established by PCR-RFLP of ITS-rDNA with the enzyme DdeI. Moreover, the molecular profiles of host species, B. glabrata, B. straminea, B. tenagophila, and B. prona, infected by S. mansoni were also established. The molluscs were dissected to permit morphological identification. These results contribute to a correct identification of snails of the genus Biomphalaria and detection of these snails infected by S. mansoni.

  1. Characterization of South American Snails of the Genus Biomphalaria (Basommatophora: Planorbidae) and Schistosoma mansoni (Platyhelminthes: Trematoda) in Molluscs by PCR-RFLP.

    Science.gov (United States)

    Caldeira, Roberta Lima; Teodoro, Tatiana Maria; Jannotti-Passos, Liana Konovaloff; Lira-Moreira, Pollanah M; Goveia, Christiane De Oliveira; Carvalho, Omar Dos Santos

    2016-01-01

    The identification of snails of the genus Biomphalaria can be done using morphological characteristics which depends on the size of the snails and skill and knowledge of researcher. These methods sometimes are not adequate for identification of species. The PCR-RFLP, using the ITS region of the rDNA, has been used to identify Brazilian species of the genus Biomphalaria. Nevertheless, there is a lack of information about snails from other Latin American countries. In addition, some snails may be infected by Schistosoma mansoni and when submitted to PCR-RFLP they show molecular profiles different from those previously standardized for the other mollusc species. In this work the molecular profiles of 15 species and the subspecies were established by PCR-RFLP of ITS-rDNA with the enzyme DdeI. Moreover, the molecular profiles of host species, B. glabrata, B. straminea, B. tenagophila, and B. prona, infected by S. mansoni were also established. The molluscs were dissected to permit morphological identification. These results contribute to a correct identification of snails of the genus Biomphalaria and detection of these snails infected by S. mansoni.

  2. Helicobacter pylori induces Snail expression through ROS-mediated activation of Erk and inactivation of GSK-3β in human gastric cancer cells.

    Science.gov (United States)

    Ngo, Hoang-Kieu-Chi; Lee, Hee Geum; Piao, Juan-Yu; Zhong, Xiancai; Lee, Ha-Na; Han, Hyeong-Jun; Kim, Wonki; Kim, Do-Hee; Cha, Young-Nam; Na, Hye-Kyung; Surh, Young-Joon

    2016-12-01

    Helicobacter pylori (H. pylori) infection has been known to be implicated in human gastric carcinogenesis. Snail, the zinc-finger transcription factor known as a key inducer of changes in the cell shape and morphogenetic movement, is aberrantly overexpressed and correlates with lymph node metastasis in gastric cancer. In the present study, we investigated whether H. pylori could induce Snail activation to provoke these changes. Using a cell scatter assay, we noticed that human gastric cancer AGS cells infected with H. pylori underwent morphological changes as well as disruption of cell-cell interaction, which was then reversed by silencing of Snail by use of small interfering RNA (siRNA). In addition, infection with H. pylori resulted in an increased intracellular level of Snail in gastric cancer cells, which was abrogated in the presence of U0126 and LY294002, inhibitors of MEK/Erk and PI3K/Akt pathways, respectively. Cycloheximide pulse-chase experiments coupled with immunocytochemical analysis revealed that the induction of Snail by H. pylori was regulated at multiple levels, including increased transcription of Snail mRNA, inhibition of protein degradation, and enhancement of nuclear translocation of Snail. Pre-treatment of AGS cells with N-acetylcysteine, a well-known reactive oxygen species (ROS) scavenger, attenuated the H. pylori-induced activation of Erk, its binding to Snail promoter, inactivation of GSK-3β, and accumulation of Snail. Collectively, these findings suggest that the upregulation of Snail expression induced by H. pylori and transformation to a spindle-like shape as a consequence in gastric cancer cells are attributable to ROS-mediated activation of Erk and the inhibition of GSK-3β signaling. © 2016 Wiley Periodicals, Inc.

  3. Life table estimates of the invasive snail Physa acuta Draparnaud, 1805, occurring in India

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    Saha Chilka

    2017-03-01

    Full Text Available The life table characteristics of the invasive snail Physa acuta were assessed in the laboratory using the individuals occurring in a newly colonised area in Burdwan, West Bengal, India. Using the changes in the shell length and the body weight of the snails as surrogate, the population growth of the snails was estimated along with longevity and the fecundity schedule. The cohort of P. acuta lived for a maximum of 22 weeks with a life expectancy (ex of 7.27 weeks and the age-specific survivorship being 0.825. Increment of the shell length of the snails complied with the von Bertalanffy growth equation, lt = 11.75(1 − exp−0.17(t−0.06, and the observed and the expected data of the length at time t (lt did not vary significantly (z score = 0.230; P = 0.818; n=20 pairs. Following attainment of sexual maturity between 28 and 42 days, oviposition continued till 20 weeks time, with 0.1-10 eggs laid by each individual. The eggs present per capsule remained between 01 and 11, whilst the net reproductive rate (R0, intrinsic rate of increase (rm and the finite rate of increase (λ were 116.07, 0.1 and 1.11, respectively. The observations are similar to those made earlier on the same species but from African and South American continents. The results of the present observation are pioneer in providing the initial studies about the life history of the invasive snail P. acuta in Indian context. Using the present information as a basis, further studies including long-term population monitoring should be initiated to understand the effects of the invasive snail P. acuta in the freshwater ecosystem of West Bengal, India.

  4. Speciation and gene flow between snails of opposite chirality.

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    Angus Davison

    2005-09-01

    Full Text Available Left-right asymmetry in snails is intriguing because individuals of opposite chirality are either unable to mate or can only mate with difficulty, so could be reproductively isolated from each other. We have therefore investigated chiral evolution in the Japanese land snail genus Euhadra to understand whether changes in chirality have promoted speciation. In particular, we aimed to understand the effect of the maternal inheritance of chirality on reproductive isolation and gene flow. We found that the mitochondrial DNA phylogeny of Euhadra is consistent with a single, relatively ancient evolution of sinistral species and suggests either recent "single-gene speciation" or gene flow between chiral morphs that are unable to mate. To clarify the conditions under which new chiral morphs might evolve and whether single-gene speciation can occur, we developed a mathematical model that is relevant to any maternal-effect gene. The model shows that reproductive character displacement can promote the evolution of new chiral morphs, tending to counteract the positive frequency-dependent selection that would otherwise drive the more common chiral morph to fixation. This therefore suggests a general mechanism as to how chiral variation arises in snails. In populations that contain both chiral morphs, two different situations are then possible. In the first, gene flow is substantial between morphs even without interchiral mating, because of the maternal inheritance of chirality. In the second, reproductive isolation is possible but unstable, and will also lead to gene flow if intrachiral matings occasionally produce offspring with the opposite chirality. Together, the results imply that speciation by chiral reversal is only meaningful in the context of a complex biogeographical process, and so must usually involve other factors. In order to understand the roles of reproductive character displacement and gene flow in the chiral evolution of Euhadra, it will be

  5. Reconciling paleodistribution models and comparative phylogeography in the Wet Tropics rainforest land snail Gnarosophia bellendenkerensis (Brazier 1875).

    Science.gov (United States)

    Hugall, Andrew; Moritz, Craig; Moussalli, Adnan; Stanisic, John

    2002-04-30

    Comparative phylogeography has proved useful for investigating biological responses to past climate change and is strongest when combined with extrinsic hypotheses derived from the fossil record or geology. However, the rarity of species with sufficient, spatially explicit fossil evidence restricts the application of this method. Here, we develop an alternative approach in which spatial models of predicted species distributions under serial paleoclimates are compared with a molecular phylogeography, in this case for a snail endemic to the rainforests of North Queensland, Australia. We also compare the phylogeography of the snail to those from several endemic vertebrates and use consilience across all of these approaches to enhance biogeographical inference for this rainforest fauna. The snail mtDNA phylogeography is consistent with predictions from paleoclimate modeling in relation to the location and size of climatic refugia through the late Pleistocene-Holocene and broad patterns of extinction and recolonization. There is general agreement between quantitative estimates of population expansion from sequence data (using likelihood and coalescent methods) vs. distributional modeling. The snail phylogeography represents a composite of both common and idiosyncratic patterns seen among vertebrates, reflecting the geographically finer scale of persistence and subdivision in the snail. In general, this multifaceted approach, combining spatially explicit paleoclimatological models and comparative phylogeography, provides a powerful approach to locating historical refugia and understanding species' responses to them.

  6. Linking immune patterns and life history shows two distinct defense strategies in land snails (gastropoda, pulmonata).

    Science.gov (United States)

    Russo, Jacqueline; Madec, Luc

    2013-01-01

    Life history integration of the defense response was investigated at intra- and interspecific levels in land snails of the family Helicidae. Two hypotheses were tested: (i) fitness consequences of defense responses are closely related to life history traits such as size at maturity and life span; (ii) different pathways of the immune response based on "nonspecific" versus "specific" responses may reflect different defense options. Relevant immune responses to a challenge with E. coli were measured using the following variables: blood cell density, cellular or plasma antibacterial activity via reactive oxygen species (ROS) level, and bacterial growth inhibition. The results revealed that the largest snails did not exhibit the strongest immune response. Instead, body mass influenced the type of response in determining the appropriate strategy. Snails with a higher body mass at maturity had more robust plasma immune responses than snails with a lower mass, which had greater cell-mediated immune responses with a higher hemocyte density. In addition, ROS appeared also to be a stress mediator as attested by differences between sites and generations for the same species.

  7. Natural infection of the feline lungworm Aelurostrongylus abstrusus in the invasive snail Achatina fulica from Argentina.

    Science.gov (United States)

    Valente, Romina; Diaz, Julia Ines; Salomón, Oscar Daniel; Navone, Graciela Teresa

    2017-02-15

    The giant African snail Achatina fulica is an invasive mollusk native to Africa, the first record in Argentina was in Puerto Iguazú, in northeastern Argentina in 2010. Recently it was reported in Corrientes Province. This snail can act as an intermediate host of Metastrongyloidea nematodes of importance in public health as: Angiostrongylus cantonensis, Angiostrongylus costaricensis and Angiostrongylus vasorum. Taking into account the presence of A. fulica in Argentina, the objectives of this study is to assess the presence of Metastrongyloidea nematodes in this mollusk species in Puerto Iguazú, Misiones, close to the international border with Brazil and Paraguay. A total of 451 samples were collected from February 2014 to November 2015. The snails were processed using a digestion technique to recover the parasites. A total of 206 nematodes larvae were founded in the digestion solution of 10 hosts (P=2%; MA=0.5; MI=21). Third larval stage (L3) nematodes identified as Aelurostrongylus abstrusus were founded parasitizing the snails. No other larval stage was observed. This species has veterinary importance because it causes 'aelurostrongilosis', also known as feline strongyloidosis. This study constitutes the first record of a Metastrongyloidea nematode in A. fulica in Argentina and also highlights the susceptibility of this mollusk as intermediate host of other helminthes of health importance. The present study suggests that there is a need to establish an epidemiological monitoring system in order to prevent the possible installation of an infected mollusks focus.

  8. Eosinophilic meningitis risk associated with raw Ampullarium canaliculatus snails consumption.

    Science.gov (United States)

    Wang, Jiun-Jye; Chung, Li-Yu; Lin, Rong-Jyh; Lee, June-Der; Lin, Chaio-Wen; Yen, Chuan-Min

    2011-05-01

    In Taiwan, Angiostrongylus cantonensis infection has been reported in foreign laborers who had consumed raw Ampullarium canaliculatus snails. This study analyzed three foreign laborers who had contracted enzyme-linked immunosorbent assay-confirmed A cantonensis infection while working in Taiwan. All three workers had consumed either roasted snails or raw snails flavored with seasoning while drinking wine. This study investigated possible risk factors for A cantonensis, including naturally occurring A cantonensis in A canaliculatus snails, viability of third-stage A cantonensis larvae in raw seasoned snails and in roasted snails, infectivity of larvae, and effects of alcohol while consuming snails. Positive infection rates in snails from five different irrigation canals in south Taiwan ranged from 12.3% to 29.4% and the average number of motile larvae per infected snail ranged from 36 to 65. The number of motile and coiled larvae in snail meat after 120 minutes seasoning was 93 (27.7%) and 233 (69.3%), respectively. After 20 minutes of roasting, most larvae in the snail meat were dead. The infectivities of motile and coiled larvae from snail meat after 60 minutes seasoning were 53.2% and 33.2%, respectively, and those from snail meat after 5 minutes roasting were 33.2% and 7.0%, respectively. Eating Taiwan A canaliculatus snails raw is extremely risky given their high infection rates and infection intensities. Even after 120 minutes seasoning or after 20 minutes roasting, snail meat should be considered unsafe for human consumption. Finally, experimental rodent studies indicated that consuming alcohol while ingesting larvae does not significantly reduced infectivity.

  9. Invading freshwater snails and biological control in Martinique Island, French West Indies

    Directory of Open Access Journals (Sweden)

    Jean-Pierre Pointier

    2001-09-01

    Full Text Available Eight alien freshwater snail species were introduced into Martinique Island during the last 50 years. The introduced snails include four planorbids (Biomphalaria straminea, Helisoma duryi, Amerianna carinata and Gyraulus sp., three thiarids (Melanoides tuberculata, M. amabilis and Tarebia granifera and one ampullarid (Marisa cornuarietis. Four of these species rapidly colonized the whole Martinican hydrographic system whereas the other four remained restricted to some particular sites. The invasion processes were documented during the last 20 years and showed (i a rapid invasion of the island by several morphs of M. tuberculata at the beginning of the 80's; (ii the introduction of T. granifera in 1991 and M. amabilis in 1997; and (iii the rapid spread of these last two species throughout the island. In the years following its introduction, M. tuberculata was used in biological control experiments against the snail hosts of schistosomiasis, B. glabrata and B. straminea. Experiments were conducted with success in several groups of water-cress beds which constituted the latest transmission sites for schistosomiasis at the beginning of the 80's. A malacological survey carried out in 2000 all over the island showed the absence of B. glabrata but the presence of some residual populations of B. straminea. Long-term studies carried out in Martinique have shown that the thiarids are able to maintain relatively stable populations over a long period of time, thus preventing recolonization by the snail hosts. Within this context the invasion of the hydrographic system of Martinique by thiarid snails has resulted in an efficient and sustainable control of the intermediate hosts of schistosomiasis.

  10. Molecular characterisation of intermediate snail hosts and the search for resistance genes

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    David Rollinson

    1998-01-01

    Full Text Available The relationship between schistosomes and their intermediate hosts is an extremely intricate one with strains and species of the parasite depending on particular species of snail, which in turn may vary in their susceptibility to the parasites. In order to gain a better understanding of the epidemiology of the disease we have been investigating the use of molecular markers for snail identification and for studying host-parasite relationships. In this paper we will draw on examples concerning schistosomiasis in West and East Africa to illustrate how a molecular analysis can be used as part of a "total evidence" approach to characterisation of Bulinus species and provide insights into parasite transmission. Particular emphasis is given to ribosomal RNA genes (rRNA, random amplified polymorphic DNA (RAPDs and the mitochondrial gene cytochrome oxidase I (COI. Snails resistant to infection occur naturally and there is a genetic basis for this resistance. In Biomphalaria glabrata resistance to Schistosoma mansoni is known to be a polygenic trait and we have initiated a preliminary search for snail genomic regions linked to, or involved in, resistance by using a RAPD based approach in conjunction with progeny pooling methods. We are currently characterising a variety of STSs (sequence tagged sites associated with resistance. These can be used for local linkage and interval mapping to define genomic regions associated with the resistance trait. The development of such markers into simple dot-blot or specific PCR-based assays may have a direct and practical application for the identification of resistant snails in natural populations.

  11. Red-Rimmed Melania (Melanoides tuberculatus) - A Snail in Biscayne National Park, Florida - Harmful Invader or Just a Nuisance?

    Science.gov (United States)

    Wingard, G. Lynn; Murray, James B.; Schill, W. Bane; Phillips, Emily C.

    2008-01-01

    Potentially harmful to humans and other animals, the red-rimmed melania snail (Melanoides tuberculatus; family Thiaridae) was discovered in Biscayne National Park, Florida, in 2003 by U.S. Geological Survey (USGS) researchers. The discovery raised concerns for park managers because this aquatic non-native snail is present in significant numbers in areas frequently used by park visitors and poses a risk of exposure. Researchers are addressing questions such as: Is this species a danger to human health? How widespread is it within the park? What factors control the distribution of the species? Is its presence a threat to native animals?

  12. Statement on the identity of apple snails

    DEFF Research Database (Denmark)

    Baker, R.; Candresse, T.; Dormannsné Simon, E.

    2012-01-01

    Following a request by the European Commission, EFSA’s Panel on Plant Health was asked to deliver a statement to clarify the current scientific knowledge regarding the identity of the apple snails in the context of the evaluation of the pest risk analysis prepared by the Spanish Ministry of Envir......Following a request by the European Commission, EFSA’s Panel on Plant Health was asked to deliver a statement to clarify the current scientific knowledge regarding the identity of the apple snails in the context of the evaluation of the pest risk analysis prepared by the Spanish Ministry...

  13. Statement on the identity of apple snails

    DEFF Research Database (Denmark)

    Baker, R.; Candresse, T.; Dormannsné Simon, E.

    2012-01-01

    Following a request by the European Commission, EFSA’s Panel on Plant Health was asked to deliver a statement to clarify the current scientific knowledge regarding the identity of the apple snails in the context of the evaluation of the pest risk analysis prepared by the Spanish Ministry of Envir......Following a request by the European Commission, EFSA’s Panel on Plant Health was asked to deliver a statement to clarify the current scientific knowledge regarding the identity of the apple snails in the context of the evaluation of the pest risk analysis prepared by the Spanish Ministry...

  14. Predator-prey interactions between shell-boring beetle larvae and rock-dwelling land snails.

    Science.gov (United States)

    Baalbergen, Els; Helwerda, Renate; Schelfhorst, Rense; Castillo Cajas, Ruth F; van Moorsel, Coline H M; Kundrata, Robin; Welter-Schultes, Francisco W; Giokas, Sinos; Schilthuizen, Menno

    2014-01-01

    Drilus beetle larvae (Coleoptera: Elateridae) are specialized predators of land snails. Here, we describe various aspects of the predator-prey interactions between multiple Drilus species attacking multiple Albinaria (Gastropoda: Clausiliidae) species in Greece. We observe that Drilus species may be facultative or obligate Albinaria-specialists. We map geographically varying predation rates in Crete, where on average 24% of empty shells carry fatal Drilus bore holes. We also provide first-hand observations and video-footage of prey entry and exit strategies of the Drilus larvae, and evaluate the potential mutual evolutionary impacts. We find limited evidence for an effect of shell features and snail behavioral traits on inter- and intra-specifically differing predation rates. We also find that Drilus predators adjust their predation behavior based on specific shell traits of the prey. In conclusion, we suggest that, with these baseline data, this interesting predator-prey system will be available for further, detailed more evolutionary ecology studies.

  15. PCR-RFLP Analysis of 28 SrDNA for Specification of Fasciola gigantica (Cobbold, 1855) in the Infected Lymnaea auricularia (Linnaeus, 1785) Snails from Northwestern Iran.

    Science.gov (United States)

    Yakhchali, Mohammad; Malekzadeh-Viayeh, Reza; Imani-Baran, Abass

    2014-09-01

    Fasciolosis in livestock is a crucial concern in the globe, mainly due to its impact on human health. The aim of this study was to determine the rate of infection with Fasciola gigantica (Cobbold, 1855) larvae in the field-collected snails of Lymnaea auricularia (Linnaeus, 1785) from northwestern Iran using a molecular approach. A total of 6,759 pond snails were collected from 28 freshwater bodies in West Azarbaijan. PCR was performed to amplify a 618-bp fragment of the nuclear 28 SrRNA gene of Fasciola. The PCR products were digested by AvaII restriction enzyme to create restriction fragment length polymorphism (RFLP) patterns specific for the detection of F. gigantica. Of the total collected snails 496 (7.34 %) were L. auricularia, among which 4.64% (23 out of 496) were infected with a Fasciola species according to the PCR analysis. Only 2.22% (11 out of 496) of the infected snails were from the mountainous areas. The highest Fasciola infection rate recorded in the snails of a single site was 1.81% (9 out of 496 snails). Based on the RFLP pattern, F. gigantica accounted for 2.42% of the infection rates in the study sites. Application of PCR-RFLP was proven to be a useful approach for valid and robust detection of the infection with F. gigantica in its intermediate host snails. These findings may therefore be applicable for establishment of the control programs against dissemination of the infection in different regions.

  16. Utilization of the invasive plant Impatiens parviflora DC. by the snail Columella edentula Draparnaud in oak-hornbeam forests

    Directory of Open Access Journals (Sweden)

    Renata Piskorz

    2011-01-01

    Full Text Available This study investigated the extend to which the snail Columella edentula is more strongly associated with the small balsam Impatiens parviflora than with other plants in the herb layer of an oak-hornbeam forest, and to interpret the character of the interaction Impatiens parviflora - Columella edentula. Numbers of C. edentula and rates of colonization were compared on various plant species under natural and laboratory conditions. Seasonal variation in snail abundance on I. parviflora was observed on permanent plots. The leaf injuries caused by C. edentula were localized in respect of the morphological and anatomical structure of leaves. The results show that I. parviflora is one of the plant species of the herb layer that are most abundantly colonized by this snail in oak-hornbeam forest. Snail finds a plant particularly suitable as a place for resting. The most favoured attachment site is on the underside of the leaf, along the midrib, which provides the highest and relatively stable humidity, as well as protection from direct sunlight and predators. I. parviflora is also a food for the snails, but they do not eat these fragments of leaves where calcium carbonate is accumulated.

  17. Snail promotes an invasive phenotype in lung carcinoma

    Directory of Open Access Journals (Sweden)

    Merikallio Heta

    2012-11-01

    Full Text Available Abstract Background Snail is a transcriptional factor which is known to influence the epitheliomesenchymal transition (EMT by regulating adhesion proteins such as E-cadherin and claudins as well as matrix metalloproteases (MMP. Methods To evaluate the functional importance of snail, a transciptional factor involved in EMT in lung tumors, we investigated its expression in a large set of lung carcinomas by immunohistochemistry. Expression of snail and effects of snail knockdown was studied in cell lines. Results Nuclear snail expression was seen in 21% of cases this being strongest in small cell lung carcinomas (SCLC. There was significantly greater snail expression in SCLC compared to squamous cell or adenocarcinoma. Positive snail expression was associated with poor survival in the whole material and separately in squamous cell and adenocarcinomas. In Cox regression analysis, snail expression showed an independent prognostic value in all of these groups. In several cell lines knockdown of snail reduced invasion in both matrigel assay and in the myoma tissue model for invasion. The influence of snail knockdown on claudin expression was cell type specific. Snail knockdown in these cell lines modified the expression of MMP2 and MMP9 but did not influence the activation of these MMPs to any significant degree. Conclusions The results show that snail plays an important role in the invasive characteristics of lung carcinoma influencing the survival of the patients. Snail knockdown might thus be one option for targeted molecular therapy in lung cancer. Snail knockdown influenced the expression of claudins individually in a cell-line dependent manner but did not influence MMP expressions or activations to any significant degree.

  18. Heat shock protein expression in relation to reproductive cycle in land snails: Implications for survival.

    Science.gov (United States)

    Mizrahi, Tal; Heller, Joseph; Goldenberg, Shoshana; Arad, Zeev

    2011-10-01

    Land snails are subject to daily and seasonal variations in temperature and in water availability and use heat shock proteins (HSPs) as part of their survival strategy. We tested whether the reproductive cycle of land snails affects the endogenous levels of HSPs, and their involvement in the reproductive process. We examined HSP levels in the foot tissue of two Sphincterochila species, S. cariosa and S. zonata, before and after laying eggs, and analyzed the albumen gland (reproductive organ) of both species and eggs of S. cariosa for the presence and quantity of various HSPs. Our study shows reduction in the expression level of Hsp70 isoforms and Hsp90 in S. zonata foot and of Hsp74 in S. cariosa foot during the period preceding egg laying compared to the post-reproductive stage. Hsp70 isoforms and Hsp25 were highly expressed in both large albumen glands and in freshly laid eggs of S. cariosa, whereas large albumen glands of S. zonata expressed mainly Hsp70 isoforms. We conclude that a trade-off between survival and fertility is responsible for the expression level of HSPs in the foot tissue of Sphincterochila snails. Our study shows that HSPs are involved in the reproductive process. We propose that parental provision of HSPs may be part of a "be prepared" strategy of Sphincterochila snails, and that HSPs may play important roles in the survival strategy of land snails during the early life stages. Our observations also highlight the importance of the reproductive status in study of whole organisms, especially when assessing the HSP response to stress.

  19. Down regulation of sodium channels in the central nervous system of hibernating snails.

    Science.gov (United States)

    Kiss, T; Battonyai, I; Pirger, Z

    2014-05-28

    Hibernation, as behavior, is an evolutionary mode of adaptation of animal species to unfavorable environmental conditions. It is generally characterized by suppressed metabolism, which also includes down regulation of the energy consuming ion-channel functioning. Experimental data regarding decreased ion-channel function are scarce. Therefore, our goal was to study the possible down regulation of voltage-gated sodium channel (NaV) subtypes in the neurons of hibernating snails. Our immunohistochemical experiments revealed that the expression of NaV1.8-like channels in the central nervous system was substantially down regulated in hibernating animals. In contrast to NaV1.8-like, the NaV1.9-like channels were present in neurons independently from hibernating and non-hibernating states. Our western blot data supported the immunohistochemical results according to which the band of the NaV1.8-like channel protein was less intensively labeled in the homogenate of the hibernating snails. The NaV1.9-like immunoreactivity was equally present both in hibernating and active snails. Micro-electrophysiological experiments show that in hibernating snails both NaV1.8- and NaV1.9-like currents are substantially decreased compared to that of the active snails. The contradictory electrophysiological and immunohistochemical or western blot data suggest that the molecular mechanisms of the "channel arrest" could be different in diverse NaV channel subtypes. Climate changes will affect temperature extremes and a question is how different species beyond their physiological tolerance will or able to adapt to changing environment. Hibernation is an important mode of adaptation to extreme climatic variations, and pursuant to this the present results may contribute to the study of the behavioral ecology.

  20. Prime waterfront real estate: Apple snails choose wild taro for oviposition sites

    Institute of Scientific and Technical Information of China (English)

    Colin H. KYLE; Alexis W. KROPF; Romi L. BURKS

    2011-01-01

    While difficult to prevent introductions,scientific research can help guide control efforts of exotic,invasive species.South American island apple snails Pomacea insularum have quickly spread across the United States Gulf Coast and few control measures exist to delay their spread.Usually occupying cryptic benthic habitats,female apple snails crawl out of the water to deposit large,bright pink egg clutches on emergent objects.To help identify the most likely place to find and remove clutches,we conducted four lab experiments to investigate what specific object qualities (i.e.material; shape and height; plant species; natural and artificial) amacted P.insularum females to lay clutches.In our fourth experiment,we specifically examined the relationship between female size and reproductive output.To further understand reproductive output,we quantified experimental clutch characteristics (height above water,dimensions,mass,approximate volume,number of eggs,hatching efficiency).Pomacea insularum females laid more clutches on plant material,chose round over flat surfaces and failed to differentiate between tall and short structures.In comparison to a common native plant in the eastern US,Pontederia cordata,snails clearly preferred to lay clutches on a widely distributed exotic,invasive plant (wild taro,Colocasia esculenta).Unexpectedly,smaller snails showed higher overall total fecundity as well as more eggs per clutch than larger snails.Therefore,hand removal efforts of large females may not be enough to slow down clutch production.Collectively,our results indicate that conservationists and managers should search emergent plants for P.insularum clutches carefully to guard against established populations [Current Zoology 57 (5):630-641,2011].

  1. Prime waterfront real estate: Apple snails choose wild taro for oviposition sites

    Directory of Open Access Journals (Sweden)

    Colin H. KYLE, Alexis W. KROPF, Romi L. BURKS

    2011-10-01

    Full Text Available While difficult to prevent introductions, scientific research can help guide control efforts of exotic, invasive species. South American island apple snails Pomacea insularum have quickly spread across the United States Gulf Coast and few control measures exist to delay their spread. Usually occupying cryptic benthic habitats, female apple snails crawl out of the water to deposit large, bright pink egg clutches on emergent objects. To help identify the most likely place to find and remove clutches, we conducted four lab experiments to investigate what specific object qualities (i.e. material; shape and height; plant species; natural and artificial attracted P. insularum females to lay clutches. In our fourth experiment, we specifically examined the relationship between female size and reproductive output. To further understand reproductive output, we quantified experimental clutch chara- cteristics (height above water, dimensions, mass, approximate volume, number of eggs, hatching efficiency. Pomacea insularum females laid more clutches on plant material, chose round over flat surfaces and failed to differentiate between tall and short structures. In comparison to a common native plant in the eastern US, Pontederia cordata, snails clearly preferred to lay clutches on a widely distributed exotic, invasive plant (wild taro, Colocasia esculenta. Unexpectedly, smaller snails showed higher overall total fecundity as well as more eggs per clutch than larger snails. Therefore, hand removal efforts of large females may not be enough to slow down clutch production. Collectively, our results indicate that conservationists and managers should search emergent plants for P. insularum clutches carefully to guard against established populations [Current Zoology 57 (5: 630–641, 2011].

  2. Comparative Studies on the Composition and Purchase Costs of some Edible Land Snails in Nigeria

    Directory of Open Access Journals (Sweden)

    Omo Erigbe, P.

    2009-01-01

    Full Text Available Four species of edible land snails of the moist forest belt of Nigeria, Archachatina marginata (Swainson, Archachatina papyracae (Pfeiffer, Limicolaria flammea (Muller and Limicolaria aurora (Jay were used in the study of their body composition and purchase cost analysis. Data on Limicolaria flammea and Limicolaria aurora were pooled together to simulate their occurrence in nature and presentation in the markets. They were designated as Limicolaria flammea / aurora throughout this study. The results showed that there was no significant (P> 0.05 difference between the dressing out percentages of the three study group of snails. However, all body component parts studied were significantly (P< 0.01 greater for A. marginata than for A. papyracae or L. flammea/aurora. When the mean weights of shell, visceral mass, edible flesh and the sum of the mean weights of drainable fluid, mucus and other wettings were in each case expressed as percentages of the liveweight, the results were consistently similar (P> 0.05, indicating some regular pattern of weight distribution for these mollusk species studied. When the cost implications were carefully analyzed, the results showed possible savings of $ 1.95 and $ 2.06 US dollars in favour of consumption of fresh edible snail meat from one kilogram liveweight each of A. papyracae and L. flammea/aurora respectively, as compared to the consumption of fresh edible snail meat from one kilogram liveweight of A. marginata. On dried snail meat basis, A. papyracae was cheapest ($ 0.28 US dollars / 100 g, followed closely by L. flammea/aurora ($0.40 US dollars / 100 g, while A. marginata was the costliest ($ 2.30 US dollars / 100 g.

  3. Calcium, snails, and birds: a case study

    Directory of Open Access Journals (Sweden)

    R. Mänd

    2000-10-01

    Full Text Available Recent studies have shown that wild birds breeding in acidified areas have difficulties with obtaining sufficient calcium for their eggshells, and that the cause of it is the shortage of land snails. Many birds have to search for Ca-rich snail shells on a daily basis during egg production. Molluscs depend on litter calcium, which has decreased due to acidification of the environment. Calcium limitation may be a widespread phenomenon also in non-acidified, naturally Ca-poor areas. The problem is that while in the latter areas the time for development of specific adaptations may have been sufficient, then in acidified areas, on the contrary, calcium shortage is a recent phenomenon. Therefore, since the extent of calcium limitation in non-acidified areas is hard to derive from observational data, experimental approach is needed. We provide experimental evidence that specific calcium deficit does affect reproductive traits also in the birds breeding in naturally base-poor habitats. Our study was conducted in a heterogeneous woodland area in Estonia containing deciduous forest patches as well as base-poor pine forest with low snail abundance. Ca supplementation, using snail shell and chicken eggshell fragments, was carried out for pied flycatchers and great tits. Extra calcium affected positively several reproductive traits like egg volume and eggshell thickness, start of breeding, and fledglings’ parameters. The negative relationship between calcium availability and lay-date suggests that birds adjust their breeding tactics to conditions of Ca deficiency, for example, by postponing laying.

  4. A "Love" Dart Allohormone Identified in the Mucous Glands of Hermaphroditic Land Snails.

    Science.gov (United States)

    Stewart, Michael J; Wang, Tianfang; Koene, Joris M; Storey, Kenneth B; Cummins, Scott F

    2016-04-08

    Animals have evolved many ways to enhance their own reproductive success. One bizarre sexual ritual is the "love" dart shooting of helicid snails, which has courted many theories regarding its precise function. Acting as a hypodermic needle, the dart transfers an allohormone that increases paternity success. Its precise physiological mechanism of action within the recipient snail is to close off the entrance to the sperm digestion organ via a contraction of the copulatory canal, thereby delaying the digestion of most donated sperm. In this study, we used the common garden snailCornu aspersumto identify the allohormone that is responsible for this physiological change in the female system of this simultaneous hermaphrodite. The love dart allohormone (LDA) was isolated from extracts derived from mucous glands that coat the dart before it is stabbed through the partner's body wall. We isolated LDA from extracts using bioassay-guided contractility measurement of the copulatory canal. LDA is encoded within a 235-amino acid precursor protein containing multiple cleavage sites that, when cleaved, releases multiple bioactive peptides. Synthetic LDA also stimulated copulatory canal contractility. Combined with our finding that the protein amino acid sequence resembles previously described molluscan buccalin precursors, this indicates that LDA is partially conserved in helicid snails and less in other molluscan species. In summary, our study provides the full identification of an allohormone that is hypodermically injected via a love dart. More importantly, our findings have important consequences for understanding reproductive biology and the evolution of alternative reproductive strategies.

  5. Specialized insulin is used for chemical warfare by fish-hunting cone snails

    Science.gov (United States)

    Safavi-Hemami, Helena; Gajewiak, Joanna; Karanth, Santhosh; Robinson, Samuel D.; Ueberheide, Beatrix; Douglass, Adam D.; Schlegel, Amnon; Imperial, Julita S.; Watkins, Maren; Bandyopadhyay, Pradip K.; Yandell, Mark; Li, Qing; Purcell, Anthony W.; Norton, Raymond S.; Ellgaard, Lars; Olivera, Baldomero M.

    2015-01-01

    More than 100 species of venomous cone snails (genus Conus) are highly effective predators of fish. The vast majority of venom components identified and functionally characterized to date are neurotoxins specifically targeted to receptors, ion channels, and transporters in the nervous system of prey, predators, or competitors. Here we describe a venom component targeting energy metabolism, a radically different mechanism. Two fish-hunting cone snails, Conus geographus and Conus tulipa, have evolved specialized insulins that are expressed as major components of their venoms. These insulins are distinctive in having much greater similarity to fish insulins than to the molluscan hormone and are unique in that posttranslational modifications characteristic of conotoxins (hydroxyproline, γ-carboxyglutamate) are present. When injected into fish, the venom insulin elicits hypoglycemic shock, a condition characterized by dangerously low blood glucose. Our evidence suggests that insulin is specifically used as a weapon for prey capture by a subset of fish-hunting cone snails that use a net strategy to capture prey. Insulin appears to be a component of the nirvana cabal, a toxin combination in these venoms that is released into the water to disorient schools of small fish, making them easier to engulf with the snail’s distended false mouth, which functions as a net. If an entire school of fish simultaneously experiences hypoglycemic shock, this should directly facilitate capture by the predatory snail. PMID:25605914

  6. Phylogenetic relationships of the operculate land snail genus Cyclophorus Montfort, 1810 in Thailand.

    Science.gov (United States)

    Nantarat, Nattawadee; Tongkerd, Piyoros; Sutcharit, Chirasak; Wade, Christopher M; Naggs, Fred; Panha, Somsak

    2014-01-01

    Operculate land snails of the genus Cyclophorus are distributed widely in sub-tropical and tropical Asia. Shell morphology is traditionally used for species identification in Cyclophorus but their shells exhibit considerable variation both within and between populations; species limits have been extremely difficult to determine and are poorly understood. Many currently recognized species have discontinuous distributions over large ranges but geographical barriers and low mobility of snails are likely to have led to long periods of isolation resulting in cryptic speciation of allopatric populations. As a contribution towards solving these problems, we reconstructed the molecular phylogeny of 87 Cyclophorus specimens, representing 29 nominal species (of which one was represented by four subspecies), plus three related out-group species. Molecular phylogenetic analyses were used to investigate geographic limits and speciation scenarios. The analyses of COI, 16S rRNA and 28S rRNA gene fragments were performed using neighbour-joining (NJ), maximum likelihood (ML), and Bayesian inference (BI) methods. All the obtained phylogenetic trees were congruent with each other and in most cases confirmed the species level classification. However, at least three nominate species were polyphyletic. Both C. fulguratus and C. volvulus appear to be species complexes, suggesting that populations of these species from different geographical areas of Thailand are cryptic species. C. aurantiacus pernobilis is distinct and likely to be a different species from the other members of the C. aurantiacus species complex.

  7. Molecular investigation of Neorickettsia risticii in trematodes and snails in a region with serological evidence of this agent in horses, state of Rio de Janeiro

    Directory of Open Access Journals (Sweden)

    R.L. Costa

    Full Text Available ABSTRACT In Brazil, some studies have indicated that Neorickettsia risticii circulates in horses, but it is unclear which are the possible intermediate vectors of this bacterium in the country. The aim of this study was to use molecular techniques in order to analyze the presence of N. risticii in snails and larval stages of trematodes in farms in a region with a history of seroreactive horses towards this bacterium, in Rio de Janeiro, Brazil. Convenience sampling was used in the studied region. The collected snails were exposed to incandescent light (60W for 2-4 hours in order to investigate trematodes in larval forms. Deoxyribonucleic acid (DNA was extracted from snail tissue and trematode. Real-time PCR (qPCR technique was used to investigate the presence of a 16S rRNA gene fragment of N. risticii. Snail specimens (n=410 were collected from 11 horse-breeding farms, and the following species were identified: Melanoides tuberculata, Pomacea sp., Biomphalaria tenagophila, Physa acuta, Drepanotrema anatinum and Biomphalaria straminea. Only 3.17% (n=13/410 of the collected snails were infected by trematodes. The cercariae obtained from these snails were classified as Megalourous cercariae, Pleurolophocercus cercariae and Furcocercous cercariae. There was no amplification of the target DNA of N. risticii in the snail and trematode samples tested by qPCR. Based on these data, the transmission of N. risticii by trematodes using these snail species in this region does not appear to occur or occurs at very low rates. Thus, further studies are needed in order to clarify which species of invertebrate hosts are infected by this bacterium and potentially participate in the transmission chain of equine neorickettsiosis in the state of Rio de Janeiro, Brazil.

  8. Stable isotope composition of land snail body water and its relation to environmental waters and shell carbonate

    Science.gov (United States)

    Goodfriend, Glenn A.; Magaritz, Mordeckai; Gat, Joel R.

    1989-12-01

    Day-to-day and within-day (diel) variations in δD and δ18O of the body water of the land snail, Theba pisana, were studied at a site in the southern coastal plain of Israel. Three phases of variation, which relate to isotopic changes in atmospheric water vapor, were distinguished: 1) on rain days, snail water becomes isotopically depleted approximately in the direction of the rain isotope values, but always less depleted in D as is atmospheric water vapor; 2) during the 1-3 days following a rain, the snail water becomes isotopically enriched along a line with slope persists until the next rain event. The isotopic variations can be explained by isotopic equilibration with atmospheric water vapor and/or uptake of dew derived therefrom. During the winter, when the snails are active, there is only very minor enrichment in 18O relative to equilibrium with water vapor or dew, apparently as a result of metabolic activity. But this enrichment becomes pronounced after long periods of inactivity. Within-day variation in body water isotopic composition is minor on non-rain days. Shell carbonate is enriched in 18O by ca. 1-2%. relative to equilibrium with body water. In most regions, the isotopic composition of atmospheric water vapor (or dew) is a direct function of that of rain. Because the isotopic composition of snail body water is related to that of atmospheric water vapor and the isotopic composition of shell carbonate in turn is related to that of body water, land snail shell carbonate 18O should provide a reliable indication of rainfall 18O. However, local environmental conditions and the ecological properties of the snail species must be taken into account.

  9. Taxonomic revision of the Elephant Pupinid snail genus Pollicaria Gould, 1856 (Prosobranchia, Pupinidae

    Directory of Open Access Journals (Sweden)

    Bangon Kongim

    2013-04-01

    Full Text Available The status of species currently assigned to the Southeast Asian Elephant Pupinid snail genus Pollicaria Gould, 1856 is reassessed. Shell, radular and reproductive morphology are investigated and analysed with reference to karyotype patterns previously reported and to distribution patterns among the species. Six previously described species are recognised: P. gravida (Benson, 1856, P. myersii (Haines, 1855, P. mouhoti (Pfeiffer, 1862, P. elephas (Morgan, 1885, P. crossei (Dautzenberg & d’Hamonville, 1887 and P. rochebruni (Mabille, 1887. A new subspecies, P. mouhoti monochroma ssp. n., is proposed and a dichotomous key to species is provided.

  10. Spatial analysis of snail distribution in Jiangning county

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhi-ying; ZHOU Yun; XU De-zhong; SUN Zhi-dong; ZHOU Xiao-nong; GONG Zi-li

    2002-01-01

    Objective: To explore the spatial distribution of oncomelenia snails in Jiangning County. Methods:Cluster analysis and the Spatial Scan Statistics were performed based on the density of alive-snails in habitats and its rate infected by the S. Japonicum. Results: Although areas of snail habitats and density of the alivesnails in marshland in 2000 are higher significantly than that in mountain areas in Jiangning County, the numbers of habitats in mountain are more than that in marshland and they distributed sporadically. The snail habitats were classified into 4 in marshlands and 3 classes in mountain areas respectively in cluster analysis.Although they are mainly the one with low density of alive and infected snails, we should alert that there are also some habitats with high snail density and infection rate, which is important for the transmission of schistosomia. The analysis of Spatial Scan Statistics detected 2 significant spatial aggregations for alive-snail in marshland and 4 in mountain areas respectively with p-values less than 0. 01. There are also 2 significant spatial aggregations for infected snails in marshland. Conclusion.. The significant spatial aggregations for alivesnails and infected snails indicated that there are some factors in the habitats suitable for the survival of snails and the transmission of schistosomia.

  11. In What Form Does Global Capital Flow Leave Behind Memories? The Story of the Apple Snail Caught Between the Green Revolution and the Organic Food Movement

    Directory of Open Access Journals (Sweden)

    Chingling Wo

    2015-07-01

    Full Text Available Focusing on a study of Taiwan’s United News Daily archive and the shifting discourses of the Green Revolution and the organic food movement, the project analyzes the narrative frameworks produced on the apple snail (Pomacea canaliculata in Taiwan. Apple snail has become invasive to many East Asian countries since the 1980s; it is considered among the world’s 100 most invasive species. During the era of the Green Revolution, the economy of killing the apple snail with pesticide was generated by a narrative of how greedy merchants imported invasive apple snail and led to the systematic disruption of Taiwan’s ecology. The paper explores how the organic food movement responded to and was shaped by such a narrative of innocence lost, and emphasizes the importance of going beyond the hyper-real narratives of irreparable ecological destructions by recognizing sites of memories left behind by global capital flow.

  12. Physiology of the invasive apple snail Pomacea maculata: tolerance to low temperatures

    Science.gov (United States)

    Deaton, Lewis E.; Schmidt, William; Leblanc, Brody; Carter, Jacoby; Mueck, Kristy; Merino, Sergio

    2016-01-01

    Apple snails of the genus Pomacea native to South America have invaded and become established in Europe, Asia, and the United States. Both the channeled apple snail Pomacea canaliculata and the island apple snail Pomacea maculata have been reported in the United States. The two species are difficult to distinguish using morphological characters, leading to uncertainty about the identity of the animals from populations in the United States. Because the snails are subtropical, their tolerance of low temperatures is a critical factor in limiting the spread of the animals from present localities along the coast of the Gulf of Mexico to more northern areas. The tolerance of P. maculata collected in Louisiana to temperatures as low as 0°C was examined. There was no mortality among animals maintained in water at temperatures of 20°C or 15°C for 10 days. Survival of animals during a 10-day exposure to water at temperatures 10°C and 5°C was 50%. The LD50 for a 10-day exposure was 7°C. Snails did not survive more than 5 days in liquid water at 0°C. Ammonia excretion by animals in temperatures of 20°C and 15°C was comparable to values reported for freshwater gastropods; at very low temperatures, excretion of ammonia was decreased. There was no difference in the mean values of the osmolality of the hemolymph of animals exposed to 20°C, 15°C and 10°C for 10 days. Sequencing of mitochondrial cytochrome oxidase 1 identified the animals in the Louisiana population used in this study as P. maculata.

  13. Soil calcium availability influences shell ecophenotype formation in the sub-antarctic land snail, Notodiscus hookeri.

    Directory of Open Access Journals (Sweden)

    Maryvonne Charrier

    Full Text Available Ecophenotypes reflect local matches between organisms and their environment, and show plasticity across generations in response to current living conditions. Plastic responses in shell morphology and shell growth have been widely studied in gastropods and are often related to environmental calcium availability, which influences shell biomineralisation. To date, all of these studies have overlooked micro-scale structure of the shell, in addition to how it is related to species responses in the context of environmental pressure. This study is the first to demonstrate that environmental factors induce a bi-modal variation in the shell micro-scale structure of a land gastropod. Notodiscus hookeri is the only native land snail present in the Crozet Archipelago (sub-Antarctic region. The adults have evolved into two ecophenotypes, which are referred to here as MS (mineral shell and OS (organic shell. The MS-ecophenotype is characterised by a thick mineralised shell. It is primarily distributed along the coastline, and could be associated to the presence of exchangeable calcium in the clay minerals of the soils. The Os-ecophenotype is characterised by a thin organic shell. It is primarily distributed at high altitudes in the mesic and xeric fell-fields in soils with large particles that lack clay and exchangeable calcium. Snails of the Os-ecophenotype are characterised by thinner and larger shell sizes compared to snails of the MS-ecophenotype, indicating a trade-off between mineral thickness and shell size. This pattern increased along a temporal scale; whereby, older adult snails were more clearly separated into two clusters compared to the younger adult snails. The prevalence of glycine-rich proteins in the organic shell layer of N. hookeri, along with the absence of chitin, differs to the organic scaffolds of molluscan biominerals. The present study provides new insights for testing the adaptive value of phenotypic plasticity in response to spatial

  14. How Much of Language, If Any, Came About in the Same Sort of Way as the Brooding Chamber in Snails?

    Science.gov (United States)

    Botha, Rudolf P.

    2001-01-01

    Critically assesses the merits and limitations of four conceptions of language genesis. Focuses on the conception that language, like the brooding chamber in certain snail species, came about through cooption as a by-product of something else. (Author/VWL)

  15. Using ensemble forecasting to examine how climate change promotes worldwide invasion of the golden apple snail (Pomacea canaliculata).

    Science.gov (United States)

    Lei, Juncheng; Chen, Lian; Li, Hong

    2017-08-01

    The golden apple snail, Pomacea canaliculata, is one of the world's 100 most notorious invasive alien species. Knowledge about the critical climate variables that limit the global distribution range of the snail, as well as predictions of future species distributions under climate change, is very helpful for management of snail. In this study, the climatically suitable habitats for this kind of snail under current climate conditions were modeled by biomod2 and projected to eight future climate scenarios (2 time periods [2050s, 2080s] × 2 Representative Concentration Pathways [RCPs; RCP2.6, RCP8.5] × 2 atmospheric General Circulation Models [GCMs; Canadian Centre for Climate Modelling and Analysis (CCCMA), Commonwealth Scientific and Industrial Research Organisation (CSIRO)]). The results suggest that the lowest temperature of coldest month is the critical climate variable to restrict the global distribution range of P. canaliculata. It is predicted that the climatically suitable habitats for P. canaliculata will increase by an average of 3.3% in 2050s and 3.8% in 2080s for the RCP2.6 scenario, while they increase by an average of 8.7% in 2050s and 10.3% in 2080s for the RCP8.5 scenario. In general, climate change in the future may promote the global invasion of the invasive species. Therefore, it is necessary to take proactive measures to monitor and preclude the invasion of this species.

  16. Intraspecific morphological and genetic variability in the European freshwater snail Radix labiata (Rossmaessler, 1835) (Gastropoda: Basommatophora: Lymnaeidae)

    NARCIS (Netherlands)

    Schniebs, K.; Glöer, P.; Vinarski, M.V.; Hundsdoerfer, A.K.

    2013-01-01

    Radix labiata is a widely distributed Palaearctic freshwater snail. This work aims to improve the knowledge of the intraspecific variability in the most important characters used for its determination. To find out which characters are really suitable to distinguish this species from other similar Ra

  17. Drift algae, an invasive snail and elevated temperature reduce ecological performance of a warm-temperate seagrass, through additive effects

    DEFF Research Database (Denmark)

    Hoffle, H.; Wernberg, T.; Thomsen, M. S.

    2012-01-01

    Seagrasses are under pressure from multiple concurrent threats, including rising temperatures, invasive species and nutrient-driven algal accumulations. We quantified the abundance of drift algae and the invasive snail Batillaria australis in 3 Halophila ovalis seagrass beds in the Swan River...... Estuary (Perth, Western Australia), and tested in an aquarium experiment for interactive effects of temperature (21 vs. 27 degrees C), cover of drift algae Chaetomorpha linum (0 vs. 1.4 kg fresh wt m(-2)) and presence (0 vs. 120 snails m(-2)) of B. australis on the ecological performance of H. ovalis....... The survey showed that drift algae varied considerably between sites and sampling times, and sites experienced average loads of 0.4 to 0.8 kg fresh wt m(-2) and extreme loads up to 2.5 kg fresh wt m(-2). In contrast, invasive snails were constantly abundant at all sites at all collection times (mean...

  18. Backbone cyclised peptides from plants show molluscicidal activity against the rice pest Pomacea canaliculata (golden apple snail).

    Science.gov (United States)

    Plan, Manuel Rey R; Saska, Ivana; Cagauan, Arsenia G; Craik, David J

    2008-07-09

    Golden apple snails ( Pomacea canaliculata) are serious pests of rice in South East Asia. Cyclotides are backbone cyclized peptides produced by plants from Rubiaceae and Violaceae. In this study, we investigated the molluscicidal activity of cyclotides against golden apple snails. Crude cyclotide extracts from both Oldenlandia affinis and Viola odorata plants showed molluscicidal activity comparable to the synthetic molluscicide metaldehyde. Individual cyclotides from each extract demonstrated a range of molluscicidal activities. The cyclotides cycloviolacin O1, kalata B1, and kalata B2 were more toxic to golden apple snails than metaldehyde, while kalata B7 and kalata B8 did not cause significant mortality. The toxicity of the cyclotide kalata B2 on a nontarget species, the Nile tilapia ( Oreochromis niloticus), was three times lower than the common piscicide rotenone. Our findings suggest that the existing diversity of cyclotides in plants could be used to develop natural molluscicides.

  19. [Expression of genes encoding defense factors in the snail Planorbarius corneus (Gastropoda, Pulmonata) infested with trematodes].

    Science.gov (United States)

    Prokhorova, E E; Tsymbalenko, N V; Ataev, G L

    2010-01-01

    Because many species of gastropods are intermediate hosts for trematodes, these molluscs are often used as model-organisms in the studies of invertebrate immune system. Revealing of the ways in which the defense factors functioning became possible due to the use of the methods of molecular biology. Contemporary molecular methods allow analyzing the defense factors allocations and levels of their expression. We investigated the expression of genes encoding defense factors in gastropods by the example of the snail Planorbarius corneus from water bodies of the Leningrad Oblast under infestation with trematods. The snails naturally infested with the parthenites of trematode species belonging to the families Strigeidae, Notocotylidae, Plagiorchiidae, and Schistosomatida were used as the experimental sample. Uninfested snails were used as a control sample. Several genes encoding the factors, which have been recently found involved in the anti-trematode defense reactions in pulmonates, were chosen, namely fibrinogen-related protein, C-lectin, calcium-binding protein, and cystatin-like protein. The genes' expression was analyzed on total mRNA samples by the reverse transcription with the polymerase chain reaction. It was shown than expression levels of the genes under consideration are different in uninfested snails and in the snails infested with different trematode species. Thus, in the mollusks infested with the parthenites of Cotylurus sp. and Bilharziella polonica, the expression levels of the genes of all factors under study were increased, while in the infested Notocotylus sp. n Plagiorchis sp., only expression levels of C-lectin and cystatin-like protein were increased. Results of the expression analysis confirm the role of hemocytes and cells of hepatopancreas in the production of humoral defense factors. In the snails infested with trematodes, the expression levels of C-lectin and calcium-binding protein genes are increased in haemocytes, while the genes of

  20. Defense response of susceptible and resistant Biomphalaria alexandrina snails against Schistosoma mansoni infection

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    Iman F. Abou-El-Naga

    2012-09-01

    Full Text Available In Egypt, Biomphalaria alexandrina is the intermediate host for Schistosoma mansoni. The fates of Schistosoma miracidia in the snails varies between different species of Biomphalaria. The internal defense system is one of the factors that influence the susceptibility pattern of the snails. The interaction between Biomphalaria snails and S. mansoni needs to be identified for each species, and even between the members of the same species with different degrees of susceptibility. In the present study, the first generation of susceptible and resistant parents of B. alexandrina was examined histologically at the 30th day post exposure. The study includes the characterization of the immune response, as expressed by tissue reactions, of susceptible and resistant B. alexandrina snails against S. mansoni. It was also designed to determine the impact of the resistance increase in parent snails, on the mechanisms of interaction of their offspring against infection. The results showed that the infection rate of the offspring from the susceptible parents was 92%. No susceptible offspring was produced from the resistant parents. When the parents were of equal number of susceptible and resistant snails, they gave an offspring with an infection rate of 20%. Susceptible snails that had susceptible parents showed a higher degree of susceptibility than those that had both susceptible and resistant parents. A common feature of the resistant snails was the absence of any viable parasites. The tissue reactions of the resistant snails having only resistant parents occurred at the site of miracidial penetration. In resistant snails for which susceptible ones were included in their parents, the reactions occurred in the deep tissues. These results characterized the immune response of B. alexandrina snails against Schistosoma infection which was found to occur by two different mechanisms. One type of defense occurs in highly resistant snails, and employs direct

  1. Prognostic significance of snail expression in hilar cholangiocarcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Dalu [Department of Hepatobiliary Surgery, Tianjin Medical University Cancer Institute and Hospital, Hexi District, Tianjin (China); Liang, Jun [Department of Oncology, Affiliated Hospital of Medical College, Qingdao University, Qingdao, Shandong Province (China); Li, Rong [Department of Hepatobiliary Surgery, Tianjin Medical University Cancer Institute and Hospital, Hexi District, Tianjin (China); Liu, Shihai [Department of Laboratory Center, Affiliated Hospital of Medical College, Qingdao University, Qingdao, Shandong Province (China); Wang, Jigang [Department of Oncology, Affiliated Hospital of Medical College, Qingdao University, Qingdao, Shandong Province (China); Zhang, Kejun; Chen, Dong [Department of General Surgery, Affiliated Hospital of Medical College, Qingdao University, Qingdao, Shandong Province (China)

    2012-05-11

    Many patients with hilar cholangiocarcinoma (HC) have a poor prognosis. Snail, a transcription factor and E-cadherin repressor, is a novel prognostic factor in many cancers. The aim of this study was to evaluate the relationship between snail and E-cadherin protein expression and the prognostic significance of snail expression in HC. We examined the protein expression of snail and E-cadherin in HC tissues from 47 patients (22 males and 25 females, mean age 61.2 years) using immunohistochemistry and RT-PCR. Proliferation rate was also evaluated in the same cases by the MIB1 index. High, low and negative snail protein expression was recorded in 18 (38%), 17 (36%), and 12 (26%) cases, respectively, and 40.4% (19/47) cases showed reduced E-cadherin protein expression in HC samples. No significant correlation was found between snail and E-cadherin protein expression levels (P = 0.056). No significant correlation was found between snail protein expression levels and gender, age, tumor grade, vascular or perineural invasion, nodal metastasis and invasion, or proliferative index. Cancer samples with positive snail protein expression were associated with poor survival compared with the negative expresser groups. Kaplan-Meier curves comparing different snail protein expression levels to survival showed highly significant separation (P < 0.0001, log-rank test). With multivariate analysis, only snail protein expression among all parameters was found to influence survival (P = 0.0003). We suggest that snail expression levels can predict poor survival regardless of pathological features and tumor proliferation. Immunohistochemical detection of snail protein expression levels in routine sections may provide the first biological prognostic marker.

  2. The Snail-Induced Sulfonation Pathway in Breast Cancer Metastasis

    Science.gov (United States)

    2014-09-01

    AD_________________ Award Number: W81XWH-11-1-0494   TITLE: The Snail -Induced Sulfonation... Snail -Induced Sulfonation Pathway in Breast Cancer Metastasis 5b. GRANT NUMBER W81XWH-11-1-0494 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Dr...provided funding for a 3-year project that has resulted in fundamental new insights into how the transcription factor Snail can control gene

  3. Haemolymph Components of Infected & None Infected Lymnaea Snails with Xiphidiocercariae

    OpenAIRE

    AA Saboor Yaraghi; A. Farahnak; MR Eshraghian

    2011-01-01

    Background: In this study the haemolymph components of infected and none infected Lymnaea gedrosiana with xiphidiocercaria larvae was compared.Methods: Five hundred Fifty Lymnaea snails were collected from Ilam and Mazandaran prov­inces, Iran, during 2008-2009. The snails were transported to the lab at Tehran University of Medi­cal Sciences and their cercarial sheddings were studied. Haemolmyphs of snails were ex­tracted and cells were counted using haemocytometer and cell-surface carbohydrat...

  4. Inheritance of Schistosoma mansoni infection incompatibility in Biomphalaria alexandrina snails

    OpenAIRE

    Iman F Abou El Naga; Eissa, Maha M.; Shereen F Mossallam; Safaa I Abd El-Halim

    2010-01-01

    In this study, we looked at the inheritance of susceptibility and resistance to Schistosoma mansoni infection in the first generation of crossbred Biomphalaria alexandrina snails. Our ultimate goal is to use such information to develop a biological method of controlling schistosomiasis. We infected laboratory-bred snails with S. mansoni miracidia and examined cercarial shedding to determine susceptibility and resistance. Five parental groups were used: Group I contained 30 susceptible snails,...

  5. Snail acetylation by histone acetyltransferase p300 in lung cancer

    OpenAIRE

    Chang, Rui; Zhang, Yinjie; Zhang, Peng; Zhou, Qinghua

    2017-01-01

    Background Epithelial to mesenchymal transition (EMT) is a complex and dynamic molecular event in lung cancer metastasis that has not yet been thoroughly investigated. EMT transcriptional factors, such as Snail, play a central role in regulation of the EMT process. In this study, we sought to identify an association between p300 and Snail in lung cancer, as well as the engagement of p300 in Snail acetylation. Methods We transfected p300 small interfering RNA into lung cancer cells to detect S...

  6. Modelling spatial distribution of snails transmitting parasitic worms with importance to human and animal health and analysis of distributional changes in relation to climate

    DEFF Research Database (Denmark)

    Pedersen, Ulrik Bo; Midzi, Nicholas; Mduluza, Takafira

    2014-01-01

    The environment, the on-going global climate change and the ecology of animal species determine the localisation of habitats and the geographical distribution of the various species in nature. The aim of this study was to explore the effects of such changes on snail species not only of interest...... to naturalists but also of importance to human and animal health. The spatial distribution of freshwater snail intermediate hosts involved in the transmission of schistosomiasis, fascioliasis and paramphistomiasis (i.e. Bulinus globosus, Biomphalaria pfeifferi and Lymnaea natalensis) were modelled by the use...... of a maximum entropy algorithm (Maxent). Two snail observation datasets from Zimbabwe, from 1988 and 2012, were compared in terms of geospatial distribution and potential distributional change over this 24-year period investigated. Climate data, from the two years were identified and used in a species...

  7. Inheritance of Schistosoma mansoni infection incompatibility in Biomphalaria alexandrina snails

    Directory of Open Access Journals (Sweden)

    Iman F Abou El Naga

    2010-03-01

    Full Text Available In this study, we looked at the inheritance of susceptibility and resistance to Schistosoma mansoni infection in the first generation of crossbred Biomphalaria alexandrina snails. Our ultimate goal is to use such information to develop a biological method of controlling schistosomiasis. We infected laboratory-bred snails with S. mansoni miracidia and examined cercarial shedding to determine susceptibility and resistance. Five parental groups were used: Group I contained 30 susceptible snails, Group II contained 30 resistant snails, Group III contained 15 susceptible and 15 resistant snails, Group IV contained 27 susceptible and three resistant snails and Group V contained three susceptible and 27 resistant snails. The percentage of resistant snails in the resulting progeny varied according to the ratio of susceptible and resistant parents per group; they are 7%, 100%, 68%, 45% and 97% from Groups I, II, III, IV and V, respectively. On increasing the percentage of resistant parent snails, the percentage of resistant progeny increased, while cercarial production in their susceptible progeny decreased.

  8. Effect of non target snails on some biological of Lymnaea natalensis snails and their infection to Fasciola gigantica.

    Science.gov (United States)

    Bakry, Fayez A; Hamdi, Salwa A H

    2006-12-01

    The influence of non-target freshwater snails (Melanoides tuberculata and Planorbis planorbis) on the capacity of Fasciola egg production F. gigantica miracidia to infect Lymnaea natalensis and their effect on mortality and growth rates showed that the snails exhibited a competitive ability against L. natalensis. The mortality rate existed in mixed cultures with snails was greatly increased, and increased with increase of snails number. The egg production and growth rate were negatively affected by the presence of M. tuberculata and P. planorbis which was more pronounced when snails were at higher ratio lL: 10D. Also, the snails showed significant degree of reduction in infection rate of L. natalensis with F. gigantica miracidia.

  9. Dietary shift in corallivorous Drupella snails following a major bleaching event at Koh Tao, Gulf of Thailand

    Science.gov (United States)

    Hoeksema, B. W.; Scott, C.; True, J. D.

    2013-06-01

    The island Koh Tao in the western Gulf of Thailand suffered severe coral bleaching in 2010. Its mushroom coral fauna of 20 species was surveyed during the bleaching in 2010 and after the bleaching in 2011. Multi-species assemblages of free-living mushroom corals occurred around the island, two of which were invaded by corallivorous Drupella snails after the bleaching. Previously these gastropods were known to mainly consume branching corals and hardly any mushroom corals. The snails were found preying on four fungiid species, three of which were susceptible to bleaching. The dietary shift became apparent after populations of preferred prey species (Acroporidae and Pocilloporidae) had died during the bleaching event. It seems that bleaching mortality reduced the availability of preferred prey, causing the corallivores to switch to less preferred species that occur in dense aggregations.

  10. Invasion biology meets parasitology: a case study of parasite spill-back with Egyptian Fasciola gigantica in the invasive snail Pseudosuccinea columella.

    Directory of Open Access Journals (Sweden)

    Daniel S Grabner

    Full Text Available The liver fluke Fasciola gigantica is a trematode parasite of ruminants and humans that occurs naturally in Africa and Asia. Cases of human fascioliasis, attributable at least in part to F. gigantica, are significantly increasing in the last decades. The introduced snail species Galba truncatula was already identified to be an important intermediate host for this parasite and the efficient invader Pseudosuccinea columella is another suspect in this case. Therefore, we investigated snails collected in irrigation canals in Fayoum governorate in Egypt for prevalence of trematodes with focus on P. columella and its role for the transmission of F. gigantica. Species were identified morphologically and by partial sequencing of the cytochrome oxidase subunit I gene (COI. Among all 689 snails found at the 21 sampling sites, P. columella was the most abundant snail with 296 individuals (42.96% and it was also the most dominant species at 10 sites. It was not found at 8 sites. Molecular detection by PCR and sequencing of the ITS1-5.8S-ITS2 region of the ribosomal DNA (rDNA revealed infections with F. gigantica (3.38%, Echinostoma caproni (2.36% and another echinostome (7.09% that could not be identified further according to its sequence. No dependency of snail size and trematode infection was found. Both high abundance of P. columella in the Fayoum irrigation system and common infection with F. gigantica might be a case of parasite spill-back (increased prevalence in local final hosts due to highly susceptible introduced intermediate host species from the introduced P. columella to the human population, explaining at least partly the observed increase of reported fascioliasis-cases in Egypt. Eichhornia crassipes, the invasive water hyacinth, which covers huge areas of the irrigation canals, offers safe refuges for the amphibious P. columella during molluscicide application. As a consequence, this snail dominates snail communities and efficiently transmits

  11. Effect of Climate Change on Invasion Risk of Giant African Snail (Achatina fulica Férussac, 1821: Achatinidae) in India.

    Science.gov (United States)

    Sarma, Roshmi Rekha; Munsi, Madhushree; Ananthram, Aravind Neelavara

    2015-01-01

    The Giant African Snail (Achatina fulica) is considered to be one the world's 100 worst invasive alien species. The snail has an impact on native biodiversity, and on agricultural and horticultural crops. In India, it is known to feed on more than fifty species of native plants and agricultural crops and also outcompetes the native snails. It was introduced into India in 1847 and since then it has spread all across the country. In this paper, we use ecological niche modeling (ENM) to assess the distribution pattern of Giant African Snail (GAS) under different climate change scenarios. The niche modeling results indicate that under the current climate scenario, Eastern India, peninsular India and the Andaman and Nicobar Islands are at high risk of invasion. The three different future climate scenarios show that there is no significant change in the geographical distribution of invasion prone areas. However, certain currently invaded areas will be more prone to invasion in the future. These regions include parts of Bihar, Southern Karnataka, parts of Gujarat and Assam. The Andaman and Nicobar and Lakshadweep Islands are highly vulnerable to invasion under changed climate. The Central Indian region is at low risk due to high temperature and low rainfall. An understanding of the invasion pattern can help in better management of this invasive species and also in formulating policies for its control.

  12. Fossil land snails of East Africa and their palaeoecological significance

    Science.gov (United States)

    Pickford, Martin

    1995-04-01

    This study deals with the Neogene and extant land snails of tropical East Africa and their implications for interpreting the paleoenvironments of the numerous localities at which they have been found. Of major significance to the study is the intimate association between the terrestrial molluscs and the rich mammalian faunas, hominoids included, of East Africa. Thus, palaeoecological reconstructions based on land snails are directly applicable to the mammalian faunas. Palaeoecological reconstructions are proposed for most of the Lower and Middle Miocene hominoids, including Proconsul, Rangwapithecus, Limnopithecus, Micropithecus, Nyanzapithecus, Kenyapithecus and others, and for the mid-Pliocene Australopithecus from Laetoli, Tanzania. The departure point for the palaeoecological reconstructions is a comprehensive study of extant terrestrial molluscs of East Africa, the habitat preferences of which are well documented. All the fossil gastropods studied comprise extant genera and even species, so the usual problems regarding the application of actualism to fossil assemblages is avoided. Furthermore, the fossil gastropod assemblages resemble extant ones, confirming their utility for such reconstructions. Among the parameters examined are rainfall, altitude, vegetation cover and type and zoogeography. A further point of interest is that the samples are more than adequate for the purposes of the study, many of the fossil localities having yielded several thousand specimens. Finally, more than 40% of the extant genera of East Africa have now been recognized in the fossil state. The molluscs are thus, by far, the best represented biological group known in the fossil record of Africa and as such hold great potential for understanding the past. This study ends with reconstructions of the palaeoecology of numerous fossiliferous localities in East Africa which have yielded molluscs and mammals. Changes through the geological column are documented and the habitat preferences

  13. Snails and their trails: the multiple functions of trail-following in gastropods.

    Science.gov (United States)

    Ng, Terence P T; Saltin, Sara H; Davies, Mark S; Johannesson, Kerstin; Stafford, Richard; Williams, Gray A

    2013-08-01

    Snails are highly unusual among multicellular animals in that they move on a layer of costly mucus, leaving behind a trail that can be followed and utilized for various purposes by themselves or by other animals. Here we review more than 40 years of experimental and theoretical research to try to understand the ecological and evolutionary rationales for trail-following in gastropods. Data from over 30 genera are currently available, representing a broad taxonomic range living in both aquatic and terrestrial environments. The emerging picture is that the production of mucus trails, which initially was an adaptation to facilitate locomotion and/or habitat extension, has evolved to facilitate a multitude of additional functions. Trail-following supports homing behaviours, and provides simple mechanisms for self-organisation in groups of snails, promoting aggregation and thus relieving desiccation and predation pressures. In gastropods that copulate, trail-following is an important component in mate-searching, either as an alternative, or in addition to the release of water- or air-borne pheromones. In some species, this includes a capacity of males not only to identify trails of conspecifics but also to discriminate between trails laid by females and males. Notably, trail discrimination seems important as a pre-zygotic barrier to mating in some snail species. As production of a mucus trail is the most costly component of snail locomotion, it is also tempting to speculate that evolution has given rise to various ways to compensate for energy losses. Some snails, for example, increase energy intake by eating particles attached to the mucus of trails that they follow, whereas others save energy through reducing the production of their own mucus by moving over previously laid mucus trails. Trail-following to locate a prey item or a mate is also a way to save energy. While the rationale for trail-following in many cases appears clear, the basic mechanisms of trail

  14. DNA barcode identification of freshwater snails in the family Bithyniidae from Thailand.

    Science.gov (United States)

    Kulsantiwong, Jutharat; Prasopdee, Sattrachai; Ruangsittichai, Jiraporn; Ruangjirachuporn, Wipaporn; Boonmars, Thidarut; Viyanant, Vithoon; Pierossi, Paola; Hebert, Paul D N; Tesana, Smarn

    2013-01-01

    Freshwater snails in the family Bithyniidae are the first intermediate host for Southeast Asian liver fluke (Opisthorchis viverrini), the causative agent of opisthorchiasis. Unfortunately, the subtle morphological characters that differentiate species in this group are not easily discerned by non-specialists. This is a serious matter because the identification of bithyniid species is a fundamental prerequisite for better understanding of the epidemiology of this disease. Because DNA barcoding, the analysis of sequence diversity in the 5' region of the mitochondrial COI gene, has shown strong performance in other taxonomic groups, we decided to test its capacity to resolve 10 species/ subspecies of bithyniids from Thailand. Our analysis of 217 specimens indicated that COI sequences delivered species-level identification for 9 of 10 currently recognized species. The mean intraspecific divergence of COI was 2.3% (range 0-9.2 %), whereas sequence divergences between congeneric species averaged 8.7% (range 0-22.2 %). Although our results indicate that DNA barcoding can differentiate species of these medically-important snails, we also detected evidence for the presence of one overlooked species and one possible case of synonymy.

  15. DNA barcode identification of freshwater snails in the family Bithyniidae from Thailand.

    Directory of Open Access Journals (Sweden)

    Jutharat Kulsantiwong

    Full Text Available Freshwater snails in the family Bithyniidae are the first intermediate host for Southeast Asian liver fluke (Opisthorchis viverrini, the causative agent of opisthorchiasis. Unfortunately, the subtle morphological characters that differentiate species in this group are not easily discerned by non-specialists. This is a serious matter because the identification of bithyniid species is a fundamental prerequisite for better understanding of the epidemiology of this disease. Because DNA barcoding, the analysis of sequence diversity in the 5' region of the mitochondrial COI gene, has shown strong performance in other taxonomic groups, we decided to test its capacity to resolve 10 species/ subspecies of bithyniids from Thailand. Our analysis of 217 specimens indicated that COI sequences delivered species-level identification for 9 of 10 currently recognized species. The mean intraspecific divergence of COI was 2.3% (range 0-9.2 %, whereas sequence divergences between congeneric species averaged 8.7% (range 0-22.2 %. Although our results indicate that DNA barcoding can differentiate species of these medically-important snails, we also detected evidence for the presence of one overlooked species and one possible case of synonymy.

  16. Morphological Characteristics and Phylogenetic Trends of Trematode Cercariae in Freshwater Snails from Nakhon Nayok Province, Thailand

    Science.gov (United States)

    Chontananarth, Thapana; Tejangkura, Thanawan; Wetchasart, Napat; Chimburut, Cherdchay

    2017-01-01

    The prevalence of cercarial infection in freshwater snails and their evolutionary trends were studied in Nakhon Nayok province, Thailand. A total of 2,869 individual snails were examined for parasitic infections. The results showed that 12 snail species were found to host larval stages of trematodes with an overall prevalence of 4.7%. The infected specimens included 7 types at the cercarial stage; cercariae, megalurous cercariae, echinostome cercariae, furcocercous cercariae, parapleurolophocercous cercariae, virgulate cercariae, and xiphidiocercariae. Regarding molecular identification, ITS2 sequence data of each larval trematode were analyzed, and a dendrogram was constructed using the neighbor-joining method with 10,000 replicates. The dendrogram was separated into 6 clades (order/family), including Echinostomatida/Echinostomatidae, Echinostomatida/Philophthalmidae, Opisthorchiida/Heterophyidae, Plagiorchiida/Prosthogonimidae, Plagiorchiida/Lecithodendriidae, and Strigeatida/Cyathocotylidae. These findings were used to confirm morphological characteristics and evolutionary trends of each type of cercariae discovered in Nakhon Nayok province. Furthermore, this investigation confirmed that the ITS2 data of cercariae could be used to study on phylogenetic relationships or to determine classification of this species at order and/or family level when possible. PMID:28285506

  17. Morphological Characteristics and Phylogenetic Trends of Trematode Cercariae in Freshwater Snails from Nakhon Nayok Province, Thailand.

    Science.gov (United States)

    Chontananarth, Thapana; Tejangkura, Thanawan; Wetchasart, Napat; Chimburut, Cherdchay

    2017-02-01

    The prevalence of cercarial infection in freshwater snails and their evolutionary trends were studied in Nakhon Nayok province, Thailand. A total of 2,869 individual snails were examined for parasitic infections. The results showed that 12 snail species were found to host larval stages of trematodes with an overall prevalence of 4.7%. The infected specimens included 7 types at the cercarial stage; cercariae, megalurous cercariae, echinostome cercariae, furcocercous cercariae, parapleurolophocercous cercariae, virgulate cercariae, and xiphidiocercariae. Regarding molecular identification, ITS2 sequence data of each larval trematode were analyzed, and a dendrogram was constructed using the neighbor-joining method with 10,000 replicates. The dendrogram was separated into 6 clades (order/family), including Echinostomatida/Echinostomatidae, Echinostomatida/Philophthalmidae, Opisthorchiida/Heterophyidae, Plagiorchiida/Prosthogonimidae, Plagiorchiida/Lecithodendriidae, and Strigeatida/Cyathocotylidae. These findings were used to confirm morphological characteristics and evolutionary trends of each type of cercariae discovered in Nakhon Nayok province. Furthermore, this investigation confirmed that the ITS2 data of cercariae could be used to study on phylogenetic relationships or to determine classification of this species at order and/or family level when possible.

  18. Strategic ejaculation in simultaneously hermaphroditic land snails: more sperm into virgin mates.

    Science.gov (United States)

    Kimura, Kazuki; Chiba, Satoshi

    2013-12-05

    It has been theorised that sperm competition promotes the strategic usage of costly sperm. Although sperm competition is thought to be an important driving force of reproductive traits in simultaneous hermaphrodites as well as in species with separate sexes, empirical studies on strategic ejaculation in simultaneous hermaphrodites are scarce. In the present study, we tested whether the simultaneously hermaphroditic land snail Euhadra quaesita adjusts the number of sperm donated according to the condition of the mate and whether the pattern of strategic ejaculation is in line with previously suggested theories. We found that individuals donated much more sperm when they copulated with a virgin mate than when they copulated with a non-virgin. The virgin-biased pattern of ejaculation matches the theoretical prediction and suggests that sperm competition significantly influence the reproductive traits of simultaneously hermaphroditic land snails.

  19. Risk assessment on the possible introduction of three predatory snails (Ocinebrellus inornatus, Urosalpinx cinerea, Rapana venosa in the Dutch Wadden Sea

    NARCIS (Netherlands)

    Fey-Hofstede, F.E.; Brink, van den A.M.; Wijsman, J.W.M.; Bos, O.G.

    2010-01-01

    Recently three alien invasive predatory snails have been found in the Dutch marine waters, which are identified by the Ministry of Agriculture, Nature and Food Quality as potential high risk species due to their possible impact on bivalve species (TRCPD/2009/3587). These are: Japanese oyster drill

  20. Epidemiological situation and molecular identification of cercarial stage in freshwater snails in Chao-Phraya Basin, Central Thailand

    Institute of Scientific and Technical Information of China (English)

    Sothorn Anucherngchai; Thanawan Tejangkura; Thapana Chontananarth

    2016-01-01

    Objective: To investigate the prevalence of cercarial trematode infection in snails and to examine the reconstruction of the phylogenetic relationship to explain the molecular system of cercarial stage trematodes to estimate the infection rate of in the definite host from the Chao-Phraya Basin.Methods: The snails were collected from 10 provinces of the Chao-Phraya Basin,Thailand by stratified sampling method. The snails were examined for cercarial infection by the crushing method. All DNA specimens were amplified with internal transcribed spacer 3(ITS3) and ITS4 primer based on PCR technique. The sequence data were aligned and used to reconstruct the phylogenetic tree by unweighted pair-group method with arithmetic means with 10 000 bootstraps.Results: The overall rate of cercarial infection was found to be 5.90%(122/2 067). Snails in the family Thiaridae were found to be in the highest prevalence followed by Lymnaeidae, Bithyniidae, Planorbidae, Viviparidae, and Ampullariidae, respectively, while the Buccinidae family(Clea helena) did not reveal any infections. The frequently found species of cercariae were parapleurolophocercous cercariae, cercariae and megarulous cercariae. The monophyletic tree separated the snails into five groups comprised of Heterophyidae, Strigeidae, Lecithodendriidae, Philophthalmidae and Echinostomatidae using the sequence of Angiostrongylus cantonensis as an out-group.Conclusions: This study was the first to report on cercarial infection in the Chao-Phraya Basin, Thailand. This revealed that a high variety of freshwater snails were infected by cercariae stage trematodes with a high prevalence. The sequence data of ITS2 can be used to investigate the phylogenetic relationships of trematodes at the family level and in each clade of different families separated by the definitive hosts.

  1. Modeling of Efficient Hot Air Drying of Apple Snails (Pomacea canaliculata for Use as a Fishmeal Protein Substitute

    Directory of Open Access Journals (Sweden)

    Du Luo

    2015-05-01

    Full Text Available Snails are a kind of important aquatic products and dehydration is the main technique in production of snail meal. Apple snail (Pomacea canaliculata dehydration meets both the demand for a fishmeal substitute in aquaculture and invasive species control in agriculture. In this study, we investigated the percentage of the nutritive material, examined the drying characteristics at 60, 80, 100 and 120°C, respectively, established a drying kinetics model and explored the effect of body morphology on drying efficiency. The results showed that the wet weight percentage of the soft parts was 46.61±6.18%. The drying efficiency was significantly improved with an increase of drying temperature from 60 to 120°C. The drying time increased rapidly when the final moisture content approached its equilibrium value. The Hii et al. model was selected as the best model to describe the drying curves (R2>0.99. It provided a relatively accurate prediction between the requirements of moisture content and drying time. There were statistically significant differences (p<0.01 in the drying time at 10.0 and 1.0% moisture content level among the four temperature groups. The drying efficiency was significantly correlated to the mass of the soft parts. It was found that 100°C was an appropriate temperature to effectively dehydrate the fresh apple snails, whereas 60°C was not suitable when air velocity ≤0.5 m/s. This study explored an integrated approach to efficiently dehydrate snails for snail meal production, which will benefit both aquaculture and agriculture.

  2. The effects of water quality and age on the acute toxicity of copper to the Florida apple snail, Pomacea paludosa.

    Science.gov (United States)

    Rogevich, E C; Hoang, T C; Rand, G M

    2008-05-01

    Copper (Cu)-containing compounds have been used in Florida as fungicides, herbicides, and soil amendments, resulting in elevated Cu in the aquatic ecosystem. The Florida apple snail (Pomacea paludosa), a key species in south Florida, may be adversely affected by Cu. Water-quality parameters, such as hardness, dissolved organic carbon (DOC), pH, and alkalinity, affect metal bioavailability and toxicity in aquatic organisms; however, it is uncertain to what extent these factors affect Cu toxicity in the Florida apple snail. The research presented here characterized the acute (96-hour) toxicity of Cu in water to the Florida apple snail at various life stages and under different water-quality parameters. Cu was more toxic to juvenile than adult apple snails. There was no difference between the 96-hour LC(50) at pH 5.5 and 6.5; however, the 96-hour LC(50 )values at pH 7.5 and 8.5 were greater than at lower pHs. The decrease in Cu(2+) above pH 7, as predicted by the MINTEQ model, accounted for the pH effect. Cu toxicity decreased as DOC increased from 0.2 to 30 mg/L. Unlike other aquatic organisms, hardness had no effect on Cu toxicity to the Florida apple snail, suggesting another mechanism of toxicity. Whole-body tissue analysis indicated that the lethal body burden of 120-day-old snails exposed to Cu for 4 days was 30 mg/kg Cu dry weight. Multiple regression analysis indicated that Cu toxicity was a function of organism age, DOC, and pH.

  3. Supercharged Snails for Stream Ecology & Water-Quality Studies

    Science.gov (United States)

    Stewart, Arthur J.; Ryon, Michael G.

    2003-01-01

    Gill-breathing freshwater snails (Family "Pleuroceridae") are ecologically important, abundant in many streams in the United States, and easy to collect and maintain under classroom conditions. These snails can be used in classroom tests to demonstrate effects of pollutants on aquatic organisms. In more advanced classes, students can cage the…

  4. The role of DDX3 in regulating Snail.

    Science.gov (United States)

    Sun, Mianen; Song, Ling; Zhou, Tong; Gillespie, G Yancey; Jope, Richard S

    2011-03-01

    DDX3, a DEAD box protein family member, appears to promote the progression of some cancers, which may partly result from its impedance of death receptor-mediated apoptosis. We found that another mechanism by which DDX3 may aid cancer progression is by promoting increased levels of the transcription factor Snail. Snail represses expression of cellular adhesion proteins, leading to increased cell migration and metastasis of many types of cancer. Knockdown of DDX3 levels by shRNA reduced basal levels of Snail in HeLa and MCF-7 cells, and this was associated with reduced cell proliferation and migration. Snail protein and mRNA levels were increased by treatment with the HDAC inhibitors sodium butyrate or trichostatin A, and these increases were attenuated in cells with DDX3 knocked down. Treatment of cells with camptothecin was discovered to increase Snail protein levels, and this increase was diminished in cells with DDX3 knocked down. Analysis of 31 patient glioblastoma multiforme (GBM) samples revealed a significant correlation between the levels of DDX3 and Snail. Thus, DDX3 is required for basal Snail expression and increases in Snail induced by HDAC inhibitors or camptothecin, indicating that this action of DDX3 may contribute to its promotion of the progression of some cancers.

  5. Management of shells of giant African snails (Achatinidae) from the ...

    African Journals Online (AJOL)

    SARAH

    2014-12-01

    Dec 1, 2014 ... The trading of the snail in Abidjan is exclusively done by women of all ages, educated and ... The markets of Abidjan produced a large amount of empty snail shells, ..... Thus, for profit, retailers focus on A. ventricosa for.

  6. The Role of Snail in EMT and Tumorigenesis.

    Science.gov (United States)

    Wang, Yifan; Shi, Jian; Chai, Kequn; Ying, Xuhua; Zhou, Binhua P

    2013-11-01

    Epithelial-mesenchymal transition (EMT) is a highly conserved process in which polarized, immobile epithelial cells lose tight junctions, associated adherence, and become migratory mesenchymal cells. Several transcription factors, including the Snail/Slug family, Twist, δEF1/ZEB1, SIP1/ZEB2 and E12/E47 respond to microenvironmental stimuli and function as molecular switches for the EMT program. Snail is a zinc-finger transcriptional repressor controlling EMT during embryogenesis and tumor progression. Through its N-terminal SNAG domain, Snail interacts with several corepressors and epigenetic remodeling complexes to repress specific target genes, such as the E-cadherin gene (CDH1). An integrated and complex signaling network, including the RTKs, TGF-β, Notch, Wnt, TNF-α, and BMPs pathways, activates Snail, thereby inducing EMT. Snail expression correlates with the tumor grade, nodal metastasis of many types of tumor and predicts a poor outcome in patients with metastatic cancer. Emerging evidences indicate that Snail causes a metabolic reprogramming, bestows tumor cells with cancer stem cell-like traits, and additionally, promotes drug resistance, tumor recurrence and metastasis. Despite many new and exciting developments, several challenges remain to be addressed in order to understand more thoroughly the role of Snail in metastasis. Additional investigations are required to disclose the contribution of microenvironmental factors on tumor progression. This information will lead to a comprehensive understanding of Snail in cancer and will provide us with novel approaches for preventing and treating metastatic cancers.

  7. Whole genome analysis of a schistosomiasis-transmitting freshwater snail

    DEFF Research Database (Denmark)

    Adema, Coen M; Hillier, Ladeana W; Jones, Catherine S

    2017-01-01

    Biomphalaria snails are instrumental in transmission of the human blood fluke Schistosoma mansoni. With the World Health Organization's goal to eliminate schistosomiasis as a global health problem by 2025, there is now renewed emphasis on snail control. Here, we characterize the genome of Biompha...

  8. Community ecology of tropical forest snails: 30 years after Solem

    NARCIS (Netherlands)

    Schilthuizen, M.

    2011-01-01

    Since Solem’s provocative claim in the early 1980s that land snails in tropical forests are neither abundant nor diverse, at least 30 quantitative-ecological papers on tropical land snail communities have appeared. Jointly, these papers have shown that site diversity is, in fact, high in tropical fo

  9. Correlation between shell phenotype and local environment suggests a role for natural selection in the evolution of Placostylus snails.

    Science.gov (United States)

    Dowle, E J; Morgan-Richards, M; Brescia, F; Trewick, S A

    2015-08-01

    The giant edible Placostylus snails of New Caledonia occur across a wide range of environmental conditions, from the dry southwest to the wetter central and northeastern regions. In large, slow-moving animals such as Placostylus, speciation could be assumed to be largely driven by allopatry and genetic drift as opposed to natural selection. We examined variation in shell morphology using geometric morphometrics and genetic structure within two species of Placostylus (P. fibratus, P. porphyrostomus), to determine the drivers of diversity in this group. Despite the current patchy distribution of snails on New Caledonia, both mtDNA and nuclear SNP data sets (>3000 loci) showed weak admixing between populations and species. Shell morphology was concordant with the genetic clusters we identified and had a strong relationship with local environment. The genetic data, in contrast to the morphological data, did not show concordance with climatic conditions, suggesting the snails are not limited in their ability to adapt to different environments. In sympatry, P. fibratus and P. porphyrostomus maintained genetic and morphological differences, suggesting a genetic basis of phenotypic variation. Convergence of shell shape was observed in two adjacent populations that are genetically isolated but experience similar habitat and climatic conditions. Conversely, some populations in contrasting environments were morphologically distinct although genetically indistinguishable. We infer that morphological divergence in the Placostylus snails of New Caledonia is mediated by adaptation to the local environment.

  10. Eco-physiological adaptation of the land snail Achatina achatina (Gastropoda: Pulmonata in tropical agro-ecosystem

    Directory of Open Access Journals (Sweden)

    Christian O. Chukwuka

    2014-03-01

    Full Text Available The survival of land snails in an adverse environmental condition depends on the integral physiological, morphological and behavioural adaptations. These adaptations are essential in understanding the species-specific habitat requirements and in predicting their environmental responses. In this study, the monthly and the periodic patterns of eco-physiological adaptation of land snail, Achatina achatina in Nsukka tropical agro-ecosystem were assessed from December 2012 to July 2013. Standard methods were employed in sampling the land snail and determination of the water content, biochemical fuel reserves and enzyme concentrations of the samples. The present results showed that lipids were high at the beginning of aestivation and depleted as the aestivation progressed. Glycogen was significantly low throughout the aestivation months (December–March and increased in the active months (April–July. Protein content recorded a definite pattern all through the months studied. Catabolism of lactate and a decrease in activity of LDH during aestivation and substantial increase upon activation were observed. Data showed that transaminase and aspartate enzymes depleted during the aestivation months indicating that the snails may have developed potential cell injury due to oxidative stress and thermal heat. A disassociation between the physiological responses and climatic data was recorded. The physiological adaptation of A. achatina ensures regular adjustment under extreme conditions and compensates for its metabolic regulation in the tropics. It is concluded that survival of A. achatina is not environmentally predicted; rather it depends on the species-specific inherent process in predicting responses for survival.

  11. Bioactivity of miltefosine against aquatic stages of Schistosoma mansoni, Schistosoma haematobium and their snail hosts, supported by scanning electron microscopy

    Directory of Open Access Journals (Sweden)

    El Bardicy Samia

    2011-05-01

    Full Text Available Abstract Background Miltefosine, which is the first oral drug licensed for the treatment of leishmaniasis, was recently reported to be a promising lead compound for the synthesis of novel antischistosomal derivatives with potent activity in vivo against different developmental stages of Schistosoma mansoni. In this paper an in vitro study was carried out to investigate whether it has a biocidal activity against the aquatic stages of Schistosoma mansoni and its snail intermediate host, Biomphalaria alexandrina , thus being also a molluscicide. Additionally, to see whether miltefosine can have a broad spectrum antischistosomal activity, a similar in vitro study was carried out on the adult stage of Schistosoma haematobium, the second major human species, its larval stages and snail intermediate host, Bulinus truncutes. This was checked by scanning electron microscopy. Results Miltefosine proved to have in vitro ovicidal, schistolarvicidal and lethal activity on adult worms of both Schistosoma species and has considerable molluscicidal activity on their snail hosts. Scanning electron microscopy revealed several morphological changes on the different stages of the parasite and on the soft body of the snail, which further strengthens the current evidence of miltefosine's activity. This is the first report of mollusicidal activity of miltefosine and its in vitro schistosomicidal activity against S.haematobium. Conclusions This study highlights miltefosine not only as a potential promising lead compound for the synthesis of novel broad spectrum schistosomicidal derivatives, but also for molluscicidals.

  12. Microhabitats within Venomous Cone Snails Contain Diverse Actinobacteria▿ †

    Science.gov (United States)

    Peraud, Olivier; Biggs, Jason S.; Hughen, Ronald W.; Light, Alan R.; Concepcion, Gisela P.; Olivera, Baldomero M.; Schmidt, Eric W.

    2009-01-01

    Actinomycetes can be symbionts in diverse organisms, including both plants and animals. Some actinomycetes benefit their host by producing small molecule secondary metabolites; the resulting symbioses are often developmentally complex. Actinomycetes associated with three cone snails were studied. Cone snails are venomous tropical marine gastropods which have been extensively examined because of their production of peptide-based neurological toxins, but no microbiological studies have been reported on these organisms. A microhabitat approach was used in which dissected tissue from each snail was treated as an individual sample in order to explore bacteria in the tissues separately. Our results revealed a diverse, novel, and highly culturable cone snail-associated actinomycete community, with some isolates showing promising bioactivity in a neurological assay. This suggests that cone snails may represent an underexplored reservoir of novel actinomycetes of potential interest for drug discovery. PMID:19749071

  13. Freshwater snails and Schistosomiasis mansoni in the state of Rio de Janeiro, Brazil: III - Baixadas Mesoregion

    Directory of Open Access Journals (Sweden)

    Silvana C Thiengo

    2002-10-01

    Full Text Available In this paper, the third of a series dealing with the survey of freshwater gastropods of the state of Rio de Janeiro, the results of collections carried out in the Mesoregion Baixadas from 2000 to 2002 are presented. Twenty-two species, belonging to seven families, were found. As to the snail intermediate hosts of Schistosoma mansoni, the most frequent species was Biomphalaria tenagophila besides some new findings of Biomphalaria straminea. No specimens were found harboring larval forms of S. mansoni although different kinds of cercariae had been observed.

  14. Thermal tolerance and climate warming sensitivity in tropical snails.

    Science.gov (United States)

    Marshall, David J; Rezende, Enrico L; Baharuddin, Nursalwa; Choi, Francis; Helmuth, Brian

    2015-12-01

    Tropical ectotherms are predicted to be especially vulnerable to climate change because their thermal tolerance limits generally lie close to current maximum air temperatures. This prediction derives primarily from studies on insects and lizards and remains untested for other taxa with contrasting ecologies. We studied the HCT (heat coma temperatures) and ULT (upper lethal temperatures) of 40 species of tropical eulittoral snails (Littorinidae and Neritidae) inhabiting exposed rocky shores and shaded mangrove forests in Oceania, Africa, Asia and North America. We also estimated extremes in animal body temperature at each site using a simple heat budget model and historical (20 years) air temperature and solar radiation data. Phylogenetic analyses suggest that HCT and ULT exhibit limited adaptive variation across habitats (mangroves vs. rocky shores) or geographic locations despite their contrasting thermal regimes. Instead, the elevated heat tolerance of these species (HCT = 44.5 ± 1.8°C and ULT = 52.1 ± 2.2°C) seems to reflect the extreme temperature variability of intertidal systems. Sensitivity to climate warming, which was quantified as the difference between HCT or ULT and maximum body temperature, differed greatly between snails from sunny (rocky shore; Thermal Safety Margin, TSM = -14.8 ± 3.3°C and -6.2 ± 4.4°C for HCT and ULT, respectively) and shaded (mangrove) habitats (TSM = 5.1 ± 3.6°C and 12.5 ± 3.6°C). Negative TSMs in rocky shore animals suggest that mortality is likely ameliorated during extreme climatic events by behavioral thermoregulation. Given the low variability in heat tolerance across species, habitat and geographic location account for most of the variation in TSM and may adequately predict the vulnerability to climate change. These findings caution against generalizations on the impact of global warming across ectothermic taxa and highlight how the consideration of nonmodel animals, ecological transitions

  15. Dose-effects relationships in wild populations of the aquatic snail Campeloma decisum at Chalk River Laboratories

    Energy Technology Data Exchange (ETDEWEB)

    Ruedig, E. [Colorado State University (United States); Higley, K. [Oregon State University (United States)

    2014-07-01

    In the last decade regulatory bodies worldwide have implemented standards to protect populations of non-human biota (NHB) from the consequences of radiation exposure. This is a departure from previous regulatory frameworks, which were concerned only with protecting man. The implementation of these new standards initiated an ongoing discussion concerning appropriate dose-rate limits for NHB. For the most part, the data utilized for estimating appropriately protective dose-rate limits has come from data collected via the irradiation of NHB in a laboratory setting. While some dose-effects studies have been performed under field conditions, such experiments represent a minority of the available data. This deficit in the literature has resulted in challenges to the established paradigm, with researchers reporting increased radiosensitivity in NHB under field conditions. However, many such studies overlook critical components of dose-effects analysis: lacking either robust ecological technique or dosimetric rigor. The study cited herein provides rigorous analysis of factors affecting populations of aquatic snails and is intended as a framework for identifying those factors statistically indicative of snail population. These benchmarks (e.g., number of snails, mass of individuals) were employed as proxies for snail population health, and how it was impacted by over two dozen environmental variables. Dose-rates were calculated via a novel voxel model, developed for this study to estimate internal dose rates for the species of interest. A linear regression model was employed to tease out the relationship between individual snails, their environment, and radiation dose rate. There was no evidence that snail population health was influenced by radiation exposure (p=0.70) at the observed dose rates. Of the environmental variables tested, water concentration of Ca was well correlated with snail mass size (p<0.001), while water concentration of P was well correlated with the

  16. Modeling snail breeding in Bioregenerative Life Support System

    Science.gov (United States)

    Kovalev, Vladimir; Tikhomirov, Alexander A.; Nickolay Manukovsky, D..

    It is known that snail meat is a high quality food that is rich in protein. Hence, heliciculture or land snail farming spreads worldwide because it is a profitable business. The possibility to use the snails of Helix pomatia in Biological Life Support System (BLSS) was studied by Japanese Researches. In that study land snails were considered to be producers of animal protein. Also, snail breeding was an important part of waste processing, because snails were capable to eat the inedible plant biomass. As opposed to the agricultural snail farming, heliciculture in BLSS should be more carefully planned. The purpose of our work was to develop a model for snail breeding in BLSS that can predict mass flow rates in and out of snail facility. There are three linked parts in the model called “Stoichiometry”, “Population” and “Mass balance”, which are used in turn. Snail population is divided into 12 age groups from oviposition to one year. In the submodel “Stoichiometry” the individual snail growth and metabolism in each of 12 age groups are described with stoichiometry equations. Reactants are written on the left side of the equations, while products are written on the right side. Stoichiometry formulas of reactants and products consist of four chemical elements: C, H, O, N. The reactants are feed and oxygen, products are carbon dioxide, metabolic water, snail meat, shell, feces, slime and eggs. If formulas of substances in the stoichiometry equations are substituted with their molar masses, then stoichiometry equations are transformed to the equations of molar mass balance. To get the real mass balance of individual snail growth and metabolism one should multiply the value of each molar mass in the equations on the scale parameter, which is the ratio between mass of monthly consumed feed and molar mass of feed. Mass of monthly consumed feed and stoichiometry coefficients of formulas of meat, shell, feces, slime and eggs should be determined experimentally

  17. Study of the snail intermediate hosts for Schistosoma mansoni on Itamaracá Island in northeast Brazil: spatial displacement of Biomphalaria glabrata by Biomphalaria straminea

    Directory of Open Access Journals (Sweden)

    Constança S. Barbosa

    2014-05-01

    Full Text Available In 2012 a malacological survey of the breeding sites of Biomphalaria glabrata and B. straminea, the two intermediate host snails of Schistosoma mansoni, was carried out on Itamaraca Island in Pernambuco, Brazil. This study has now been extended by studying the competition between the two species. Snails were collected and dissected to identify the species and tests were performed to verify S. mansoni infection. Student’s t test was used to compare the proportion between the two species and their breeding sites and a parasitological survey was conducted among local residents, using the Kato-Katz method. The spatial distribution of the two snail species was determined using TerraView, while a snail density map was constructed by Kernel estimate. The survey identified two breeding sites for B. glabrata with 17 specimens and 19 breeding sites for B. straminea with 459 snails, all of them negative for S. mansoni infection. The statistical analysis revealed that the proportion of the numbers of specimens and breeding sites of B. straminea (37.84 ± 9.01 were significantly greater than those of B. glabrata (8.50 ± 6.50. Parasitological examinations from 41 residents diagnosed two cases of schistosomiasis with parasite loads of 60 and 84 eggs per 1 g of stool, respectively. This indiction of a competitive process between the two snail species requires monitoring of schistosomiasis in the resident and travelling human populations occupying this environment, which could potentially result in social and economic changes on the island risking its attraction as a centre for eco-tourism.

  18. Climate and pH predict the potential range of the invasive apple snail (Pomacea insularum in the southeastern United States.

    Directory of Open Access Journals (Sweden)

    James E Byers

    Full Text Available Predicting the potential range of invasive species is essential for risk assessment, monitoring, and management, and it can also inform us about a species' overall potential invasiveness. However, modeling the distribution of invasive species that have not reached their equilibrium distribution can be problematic for many predictive approaches. We apply the modeling approach of maximum entropy (MaxEnt that is effective with incomplete, presence-only datasets to predict the distribution of the invasive island apple snail, Pomacea insularum. This freshwater snail is native to South America and has been spreading in the USA over the last decade from its initial introductions in Texas and Florida. It has now been documented throughout eight southeastern states. The snail's extensive consumption of aquatic vegetation and ability to accumulate and transmit algal toxins through the food web heighten concerns about its spread. Our model shows that under current climate conditions the snail should remain mostly confined to the coastal plain of the southeastern USA where it is limited by minimum temperature in the coldest month and precipitation in the warmest quarter. Furthermore, low pH waters (pH <5.5 are detrimental to the snail's survival and persistence. Of particular note are low-pH blackwater swamps, especially Okefenokee Swamp in southern Georgia (with a pH below 4 in many areas, which are predicted to preclude the snail's establishment even though many of these areas are well matched climatically. Our results elucidate the factors that affect the regional distribution of P. insularum, while simultaneously presenting a spatial basis for the prediction of its future spread. Furthermore, the model for this species exemplifies that combining climatic and habitat variables is a powerful way to model distributions of invasive species.

  19. First report of Lymnaea cousini Jousseaume, 1887 naturally infected with Fasciola hepatica (Linnaeus, 1758) (Trematoda: Digenea) in Machachi, Ecuador.

    Science.gov (United States)

    Villavicencio, Angel; Vasconcellos, Mauricio Carvalho de

    2005-11-01

    We report the first finding of Lymnaea cousini naturally infected with Fasciola hepatica in Ecuador. A sample of 70 snails was collected in April 2005 from a wetland located in a valley at approximately 3000 m a.s.l., near the locality of Machachi, Pichincha Province. The prevalence of natural infection in L. cousini was 31.43%, which is the highest value ever recorded for naturally infected lymnaeid species.

  20. First report of Lymnaea cousini Jousseaume, 1887 naturally infected with Fasciola hepatica (Linnaeus, 1758 (Trematoda: Digenea in Machachi, Ecuador

    Directory of Open Access Journals (Sweden)

    A Ángel Villavicencio

    2005-11-01

    Full Text Available We report the first finding of Lymnaea cousini naturally infected with Fasciola hepatica in Ecuador. A sample of 70 snails was collected in April 2005 from a wetland located in a valley at approximately 3000 m a.s.l., near the locality of Machachi, Pichincha Province. The prevalence of natural infection in L. cousini was 31.43%, which is the highest value ever recorded for naturally infected lymnaeid species.

  1. Annotated type catalogue of land snails collected from Taiwan (Formosa) in the Natural History Museum, London.

    Science.gov (United States)

    Hwang, Chung-Chi

    2014-01-01

    The present catalogue lists the type specimens of land snail species, collected from Taiwan and deposited in the Natural History Museum, London. Thirty-seven nominal species described by Pfeiffer, Adams, Nevill, Moellendorff, Godwin-Austen and Gude were traced. I present here information on type status, collection data obtained from the registers and labels of each collection, and annotations on the current taxonomic affiliation. Lectotypes of 28 nominal (sub)species were newly designated. One holotype was fixed originally and two holotypes newly fixed by monotypy. Syntypes of two species and paralectotypes of three species were also discovered in the Museum. No specimen of the species Pupina adamsi Sowerby, 1878, which was supposed to be deposited in the NHM, was found. Pictures of the name-bearing types are provided for further research on biodiversity of the island.

  2. Sexual selection on land snail shell ornamentation: a hypothesis that may explain shell diversity

    Directory of Open Access Journals (Sweden)

    Schilthuizen Menno

    2003-06-01

    Full Text Available Abstract Background Many groups of land snails show great interspecific diversity in shell ornamentation, which may include spines on the shell and flanges on the aperture. Such structures have been explained as camouflage or defence, but the possibility that they might be under sexual selection has not previously been explored. Presentation of the hypothesis The hypothesis that is presented consists of two parts. First, that shell ornamentation is the result of sexual selection. Second, that such sexual selection has caused the divergence in shell shape in different species. Testing the hypothesis The first part of the hypothesis may be tested by searching for sexual dimorphism in shell ornamentation in gonochoristic snails, by searching for increased variance in shell ornamentation relative to other shell traits, and by mate choice experiments using individuals with experimentally enhanced ornamentation. The second part of the hypothesis may be tested by comparing sister groups and correlating shell diversity with degree of polygamy. Implications of the hypothesis If the hypothesis were true, it would provide an explanation for the many cases of allopatric evolutionary radiation in snails, where shell diversity cannot be related to any niche differentiation or environmental differences.

  3. Crawling beneath the free surface: Water snail locomotion

    Science.gov (United States)

    Lee, Sungyon; Bush, John W. M.; Hosoi, A. E.; Lauga, Eric

    2008-08-01

    Land snails move via adhesive locomotion. Through muscular contraction and expansion of their foot, they transmit waves of shear stress through a thin layer of mucus onto a solid substrate. Since a free surface cannot support shear stress, adhesive locomotion is not a viable propulsion mechanism for water snails that travel inverted beneath the free surface. Nevertheless, the motion of the freshwater snail, Sorbeoconcha physidae, is reminiscent of that of its terrestrial counterparts, being generated by the undulation of the snail foot that is separated from the free surface by a thin layer of mucus. Here, a lubrication model is used to describe the mucus flow in the limit of small-amplitude interfacial deformations. By assuming the shape of the snail foot to be a traveling sine wave and the mucus to be Newtonian, an evolution equation for the interface shape is obtained and the resulting propulsive force on the snail is calculated. This propulsive force is found to be nonzero for moderate values of the capillary number but vanishes in the limits of high and low capillary number. Physically, this force arises because the snail's foot deforms the free surface, thereby generating curvature pressures and lubrication flows inside the mucus layer that couple to the topography of the foot.

  4. Anti-ulcer potentials of phylum mollusca (tropical snail) slime

    Institute of Scientific and Technical Information of China (English)

    Nwodo NJ; Okonta J M; Ezugwu CO; Attama AA

    2009-01-01

    Objective:The effectiveness of the slimy substance in snail to regenerate and repair damaged areas on its body/shell lead to this investigation.Methods:The anti-ulcer'property of snail slime extracted from phylum mollusca (tropical snail)from the giant African snail Archachatina marginata (Fam.Arionidae)was investi-gated using histamine,stress and indomethacin-induced ulcers.The solubility profile of extract was investiga-ted in different solvents and at different temperatures.Chemical analysis was carried out to determine the types of constituents present in the slim,while acute toxicity test was carried out to evaluate its profile of toxicity. The effect of the snail slim on gastrointestinal motility was investigated in mice,while the guinea pig ileum was used to study the effect of the extract on contraction produced by acetylcholine and histamine.The snail slime contained copious quantity of protein,with varying amounts of simple sugars,carbohydrates and fats.The slime was not soluble in most common solvents and increases in temperature,did not appear to increase its sol-ubility.Results:The result further indicated that although the snail slime exhibited significant (P <0.05)an-ti-ulcer induced by stress and histamine,it was most potent against ulcer induced by indomethacin.The snail slime potently inhibited gastrointestinal movement in mice in a dose-dependent manner;however,it was not a-ble to inhibit contraction induced by acetylcholine and histamine in guinea pig ileum.Conclusion:The snail mucin possesses potent antiulcer properties without any toxic effect.The mechanism responsible for the anti-ul-cer property may not be postulated with certainty but cytoprotective and anti-spasmodic activities are most likely to be involved.

  5. The direct cost of traumatic secretion transfer in hermaphroditic land snails: individuals stabbed with a love dart decrease lifetime fecundity.

    Science.gov (United States)

    Kimura, Kazuki; Chiba, Satoshi

    2015-04-07

    Several taxa of simultaneously hermaphroditic land snails exhibit a conspicuous mating behaviour, the so-called shooting of love darts. During mating, such land snail species transfer a specific secretion by stabbing a mating partner's body with the love dart. It has been shown that sperm donors benefit from this traumatic secretion transfer, because the secretions manipulate the physiology of a sperm recipient and increase the donors' fertilization success. However, it is unclear whether reception of dart shooting is costly to the recipients. Therefore, the effect of sexual conflict and antagonistic arms races on the evolution of traumatic secretion transfer in land snails is still controversial. To examine this effect, we compared lifetime fecundity and longevity between the individuals that received and did not receive dart shooting from mating partners in Bradybaena pellucida. Our experiments showed that the dart-receiving snails suffered reduction in lifetime fecundity and longevity. These results suggest that the costly mating behaviour, dart shooting, generates conflict between sperm donors and recipients and that sexually antagonistic arms races have contributed to the diversification of the morphological and behavioural traits relevant to dart shooting. Our findings also support theories suggesting a violent escalation of sexual conflict in hermaphroditic animals.

  6. Spread of the Rat Lungworm (Angiostrongylus cantonensis) in Giant African Land Snails (Lissachatina fulica) in Florida, USA.

    Science.gov (United States)

    Iwanowicz, Deborah D; Sanders, Lakyn R; Schill, W Bane; Xayavong, Maniphet V; da Silva, Alexandre J; Qvarnstrom, Yvonne; Smith, Trevor

    2015-07-01

    The rat lungworm (Angiostrongylus cantonensis) is a parasitic nematode that causes rat lungworm disease. It is the leading cause of eosinophilic meningitis and is a zoonotic health risk. We confirmed the presence of A. cantonensis using species-specific, quantitative PCR in 18 of 50 (36%) giant African land snails (Lissachatina fulica) collected from Miami, Florida, US in May 2013. These snails were collected from seven of 21 core areas that the Florida Department of Agriculture and Consumer Services monitor weekly. Rat lungworms have not previously been identified in these areas. Duplicate DNA extractions of foot muscle tissue from each snail were tested. Of the seven core areas we examined, six were positive for A. cantonensis and prevalence of infection ranged from 27% to 100%. Of the 18 positive snails, only five were positive in both extractions. Our results confirm an increase in the range and prevalence of rat lungworm infection in Miami. We also emphasize the importance of extracting sufficient host tissue to minimize false negatives.

  7. A Miocene molluscan faunule from Caucagua (Miranda State, Venezuela), with the description of a new species of Tryonia (Mollusca, Gastropoda)

    NARCIS (Netherlands)

    Wesselingh, F.P.; Macsotay, O.

    2006-01-01

    A molluscan faunule from the Miocene Cumaca Formation of the western margin of the Tuy Basin (Venezuela) is described. The fauna yields two species of freshwater snails and a single terrestrial snail species. Tryonia vivasi nov. spec. is described from the fauna, and its biogeographical significance

  8. A Miocene molluscan faunule from Caucagua (Miranda State, Venezuela), with the description of a new species of Tryonia (Mollusca, Gastropoda)

    NARCIS (Netherlands)

    Wesselingh, F.P.; Macsotay, O.

    2006-01-01

    A molluscan faunule from the Miocene Cumaca Formation of the western margin of the Tuy Basin (Venezuela) is described. The fauna yields two species of freshwater snails and a single terrestrial snail species. Tryonia vivasi nov. spec. is described from the fauna, and its biogeographical significance

  9. Factors controlling carbon isotopic composition of land snail shells estimated from lab culturing experiment

    Science.gov (United States)

    Zhang, Naizhong; Yamada, Keita; Yoshida, Naohiro

    2014-05-01

    Carbon isotopic composition (δ13C) of land snail shell carbonate is widely applied in reconstructing the C3/C4 vegetation distribution of paleo-environment, which is considered to reflect variations of some environmental parameters [1][2][3]. Land snail shell carbon has three potential sources: diet, atmospheric CO2 and ingested carbonate (limestone) [4]. However, their relative contributions to shell carbonate have not been understood well yet [4][5][6][7][8]. More researches are necessary before we could apply this tool in paleo-environment reconstruction, especially inter-lab culturing experiment. A kind of land snail species, Acusta despecta sieboldiana, was collected at Yokohama, Japan and cultured under suitable environment to lay eggs. The second generations were growing up from eggs to adults around 6-12 months at the temperature of 20°, 25° and 30°, respectively. All of the snails at 25° and 30° and most of those at 20° were fed by cabbage (C3 plant) during their life span while others were fed by corn (C4 plant). To investigate the effect of ingested carbonate, some of them were fed by Ca3(PO4)2 powder while others were fed by CaCO3 powder. δ13C of shells were analyzed by an Isotope Ratio Mass Spectrometry (Thermo Finnigan MAT 253); δ13C of food and snail tissue were measured by a Cavity Ring-Down Spectroscopy (Picarro G1121-i). At the same time, δ13C of eggshell and new born snails were analyzed by a Continuous Flow Isotope Ratio Mass Spectrometry (GasBench II). We confirmed that diet, atmospheric CO2 and ingested limestone could be important sources controlling shell δ13C values. And the temperature could affect shell carbonate δ13C values, too. A simple but credible frame was raised to discuss the mechanism of how each possible source and environmental parameter could affect shell carbonate δ13C values based on previous works [4][6][8] and this study. According to this frame and some reasonable assumptions, we have estimated the

  10. Molecular Evolution of Freshwater Snails with Contrasting Mating Systems.

    Science.gov (United States)

    Burgarella, Concetta; Gayral, Philippe; Ballenghien, Marion; Bernard, Aurélien; David, Patrice; Jarne, Philippe; Correa, Ana; Hurtrez-Boussès, Sylvie; Escobar, Juan; Galtier, Nicolas; Glémin, Sylvain

    2015-09-01

    Because mating systems affect population genetics and ecology, they are expected to impact the molecular evolution of species. Self-fertilizing species experience reduced effective population size, recombination rates, and heterozygosity, which in turn should decrease the efficacy of natural selection, both adaptive and purifying, and the strength of meiotic drive processes such as GC-biased gene conversion. The empirical evidence is only partly congruent with these predictions, depending on the analyzed species, some, but not all, of the expected effects have been observed. One possible reason is that self-fertilization is an evolutionary dead-end, so that most current selfers recently evolved self-fertilization, and their genome has not yet been strongly impacted by selfing. Here, we investigate the molecular evolution of two groups of freshwater snails in which mating systems have likely been stable for several millions of years. Analyzing coding sequence polymorphism, divergence, and expression levels, we report a strongly reduced genetic diversity, decreased efficacy of purifying selection, slower rate of adaptive evolution, and weakened codon usage bias/GC-biased gene conversion in the selfer Galba compared with the outcrosser Physa, in full agreement with theoretical expectations. Our results demonstrate that self-fertilization, when effective in the long run, is a major driver of population genomic and molecular evolutionary processes. Despite the genomic effects of selfing, Galba truncatula seems to escape the demographic consequences of the genetic load. We suggest that the particular ecology of the species may buffer the negative consequences of selfing, shedding new light on the dead-end hypothesis.

  11. Glowing seashells: diversity of fossilized coloration patterns on coral reef-associated cone snail (Gastropoda: Conidae shells from the Neogene of the Dominican Republic.

    Directory of Open Access Journals (Sweden)

    Jonathan R Hendricks

    Full Text Available The biology of modern Conidae (cone snails--which includes the hyperdiverse genus Conus--has been intensively studied, but the fossil record of the clade remains poorly understood, particularly within an evolutionary framework. Here, ultraviolet light is used to reveal and characterize the original shell coloration patterns of 28 species of cone snails from three Neogene coral reef-associated deposits from the Cibao Valley, northern Dominican Republic. These fossils come from the upper Miocene Cercado Fm. and lower Pliocene Gurabo Fm., and range in age from about 6.6-4.8 Ma. Comparison of the revealed coloration patterns with those of extant species allow the taxa to be assigned to three genera of cone snails (Profundiconus, Conasprella, and Conus and at least nine subgenera. Thirteen members of these phylogenetically diverse reef faunas are described as new species. These include: Profundiconus? hennigi, Conasprella (Ximeniconus ageri, Conus anningae, Conus lyelli, Conus (Atlanticonus? franklinae, Conus (Stephanoconus gouldi, Conus (Stephanoconus bellacoensis, Conus (Ductoconus cashi, Conus (Dauciconus garrisoni, Conus (Dauciconus? zambaensis, Conus (Spuriconus? kaesleri, Conus (Spuriconus? lombardii, and Conus (Lautoconus? carlottae. Each of the three reef deposits contain a minimum of 14-16 cone snail species, levels of diversity that are similar to modern Indo-Pacific reef systems. Finally, most of the 28 species can be assigned to modern clades and thus have important implications for understanding the biogeographic and temporal histories of these clades in tropical America.

  12. PCR-RFLP Analysis of 28 SrDNA for Specification of Fasciola gigantica (Cobbold, 1855 in the Infected Lymnaea auricularia (Linnaeus, 1785 Snails from Northwestern Iran.

    Directory of Open Access Journals (Sweden)

    Mohammad Yakhchali

    2014-09-01

    Full Text Available Fasciolosis in livestock is a crucial concern in the globe, mainly due to its impact on human health. The aim of this study was to determine the rate of infection with Fasciola gigantica (Cobbold, 1855 larvae in the field-collected snails of Lymnaea auricularia (Linnaeus, 1785 from northwestern Iran using a molecular approach.A total of 6,759 pond snails were collected from 28 freshwater bodies in West Azarbaijan. PCR was performed to amplify a 618-bp fragment of the nuclear 28 SrRNA gene of Fasciola. The PCR products were digested by AvaII restriction enzyme to create restriction fragment length polymorphism (RFLP patterns specific for the detection of F. gigantica.Of the total collected snails 496 (7.34 % were L. auricularia, among which 4.64% (23 out of 496 were infected with a Fasciola species according to the PCR analysis. Only 2.22% (11 out of 496 of the infected snails were from the mountainous areas. The highest Fasciola infection rate recorded in the snails of a single site was 1.81% (9 out of 496 snails. Based on the RFLP pattern, F. gigantica accounted for 2.42% of the infection rates in the study sites.Application of PCR-RFLP was proven to be a useful approach for valid and robust detection of the infection with F. gigantica in its intermediate host snails. These findings may therefore be applicable for establishment of the control programs against dissemination of the infection in different regions.

  13. Integration of an invasive consumer into an estuarine food web: direct and indirect effects of the New Zealand mud snail.

    Science.gov (United States)

    Brenneis, Valance E F; Sih, Andrew; de Rivera, Catherine E

    2011-09-01

    Introduced species interact both directly and indirectly with native species. We examine interactions between the introduced New Zealand mud snail (Potamopyrgus antipodarum) and native estuarine invertebrates and predators through experiments and field studies. A widely held management concern is that when P. antipodarum, which has low nutritional value, becomes abundant, it replaces nutritious prey in fish diets. We tested two key components of this view: (1) that fish consume, but get little direct nutritional value from P. antipodarum; and (2) that P. antipodarum has an indirect negative effect on fish by reducing the energy derived from native prey. We also examined predation by the native signal crayfish, Pacifastacus leniusculus. Laboratory feeding trials showed that both crayfish and fish consume P. antipodarum, a direct effect. Crayfish consumed and successfully digested higher numbers of snails than did fish [Pacific staghorn sculpin (Leptocottus armatus), three spine stickleback (Gasterosteus aculeatus), and juvenile starry flounder (Platicthys stellatus)]. P. antipodarum occurred at low frequencies in the stomachs of wild-caught fish. More interesting were the indirect effects of this invader, which ran counter to predictions. P. antipodarum presence was associated with no change or an increase in the amount of energy derived from native prey by predators. The presence of P. antipodarum also led to increased consumption of and preference for the native amphipod Americorophium salmonis over the native isopod Gnorimosphaeroma insulare. This is an example of short-term, asymmetric, apparent competition, in which the presence of one prey species (snails) increases predation on another prey species (the amphipod).

  14. Relationship between snail population density and infection status of snails and fish with zoonotic trematodes in Vietnamese carp nurseries

    DEFF Research Database (Denmark)

    Clausen, Jesper Hedegaard; Madsen, Henry; Murrell, Kenneth Darwin

    2012-01-01

    Fish-borne zoonotic trematodes (FZT) are a food safety and health concern in Vietnam. Humans and other final hosts acquire these parasites from eating raw or under-cooked fish with FZT metacercariae. Fish raised in ponds are exposed to cercariae shed by snail hosts that are common in fish farm...... ponds. Previous risk assessment on FZT transmission in the Red River Delta of Vietnam identified carp nursery ponds as major sites of transmission. In this study, we analyzed the association between snail population density and heterophyid trematode infection in snails with the rate of FZT transmission...

  15. Correlating molecular phylogeny with venom apparatus occurrence in Panamic auger snails (Terebridae.

    Directory of Open Access Journals (Sweden)

    Mandë Holford

    Full Text Available Central to the discovery of neuroactive compounds produced by predatory marine snails of the superfamily Conoidea (cone snails, terebrids, and turrids is identifying those species with a venom apparatus. Previous analyses of western Pacific terebrid specimens has shown that some Terebridae groups have secondarily lost their venom apparatus. In order to efficiently characterize terebrid toxins, it is essential to devise a key for identifying which species have a venom apparatus. The findings presented here integrate molecular phylogeny and the evolution of character traits to infer the presence or absence of the venom apparatus in the Terebridae. Using a combined dataset of 156 western and 33 eastern Pacific terebrid samples, a phylogenetic tree was constructed based on analyses of 16S, COI and 12S mitochondrial genes. The 33 eastern Pacific specimens analyzed represent four different species: Acus strigatus, Terebra argyosia, T. ornata, and T. cf. formosa. Anatomical analysis was congruent with molecular characters, confirming that species included in the clade Acus do not have a venom apparatus, while those in the clade Terebra do. Discovery of the association between terebrid molecular phylogeny and the occurrence of a venom apparatus provides a useful tool for effectively identifying the terebrid lineages that may be investigated for novel pharmacological active neurotoxins, enhancing conservation of this important resource, while providing supplementary information towards understanding terebrid evolutionary diversification.

  16. Correlating molecular phylogeny with venom apparatus occurrence in Panamic auger snails (Terebridae).

    Science.gov (United States)

    Holford, Mandë; Puillandre, Nicolas; Modica, Maria Vittoria; Watkins, Maren; Collin, Rachel; Bermingham, Eldredge; Olivera, Baldomero M

    2009-11-05

    Central to the discovery of neuroactive compounds produced by predatory marine snails of the superfamily Conoidea (cone snails, terebrids, and turrids) is identifying those species with a venom apparatus. Previous analyses of western Pacific terebrid specimens has shown that some Terebridae groups have secondarily lost their venom apparatus. In order to efficiently characterize terebrid toxins, it is essential to devise a key for identifying which species have a venom apparatus. The findings presented here integrate molecular phylogeny and the evolution of character traits to infer the presence or absence of the venom apparatus in the Terebridae. Using a combined dataset of 156 western and 33 eastern Pacific terebrid samples, a phylogenetic tree was constructed based on analyses of 16S, COI and 12S mitochondrial genes. The 33 eastern Pacific specimens analyzed represent four different species: Acus strigatus, Terebra argyosia, T. ornata, and T. cf. formosa. Anatomical analysis was congruent with molecular characters, confirming that species included in the clade Acus do not have a venom apparatus, while those in the clade Terebra do. Discovery of the association between terebrid molecular phylogeny and the occurrence of a venom apparatus provides a useful tool for effectively identifying the terebrid lineages that may be investigated for novel pharmacological active neurotoxins, enhancing conservation of this important resource, while providing supplementary information towards understanding terebrid evolutionary diversification.

  17. CRCP-Acropora palmata snail corallivore removal evaluation

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Corallivorous snail feeding scars are a common source of tissue loss for the threatened coral Acropora palmata, accounting for roughly one quarter of tissue loss in...

  18. Determinants of production level of commercial snail farmers in Oyo ...

    African Journals Online (AJOL)

    Analytical tools employed include frequency counts, Chi-Square and five (5) point Likert ... characteristics of respondents and their herd size, hence snail productivity. ... The study identifies housing, management and pest control as areas of ...

  19. The ecology of shell shape difference in chirally dimorphic snails

    NARCIS (Netherlands)

    Schilthuizen, M.; Haase, M.; Koops, K.; Looijes, S.M.; Hendrikse, S.

    2012-01-01

    The Southeast-Asian tree snail subgenus Amphidromus s. str. (Gastropoda Pulmonata: Camaenidae) is unusual among all gastropods for its genetic antisymmetry: populations consist of stable mixtures of individuals with clockwise (dextral) and counterclockwise (sinistral) coiling directions. Although pr

  20. Snails, stable iostopes, and southwestern desert paleoclimates

    Energy Technology Data Exchange (ETDEWEB)

    Sharpe, S.E. [Univ. and Community College System of Nevada, Reno, NV (United States); Whelan, J.F.; Forester, R.M.; Burdett, J.

    1995-09-01

    Modern and fossil molluscs (snails) occur in many localities in and semi-arid regions throughout the desert southwest. Live terrestrial snails are found under rocks and in forest litter and aquatic taxa inhabit springs, seeps, and/or wetlands. Molluscs uptake local water during their growing season (spring and summer) and incorporate its delta 180 signature into their shells. Preliminary 180 analysis of modem shells from the southern Great Basin indicates that the shells probably reflect meteoric water 180 values during the growing season. This provides a way to estimate the delta 180 value of precipitation and, thereby, the source of the moisture-bearing air masses. Significant 180 variability in shells analyzed include geographic location, elevation, taxonomy, and habitat (terrestrial, spring, or wetland). We found a rough inverse correlation with elevation in modem shells from the Spring Range in southern Nevada. The delta 180 values of modem and fossil shells are also very different; modem values in this location are much higher than those from nearby late Pleistocene-age molluscs suggesting that the Pleistocene summers were variously colder and wetter than today or less evaporative (more humid). Assuming shell material directly reflects the 180 of the growing-season environment, comparison of modem and fossil shell delta 180 values can potentially identify changes in air-mass moisture sources and can help to define seasonal precipitation change through time. Comprehension and quantification of community and isotopic variability in modem gastropods is required to create probabilistic valid transfer functions with fossil materials. Valid inferences about past environmental conditions can then be established with known confidence limits.

  1. The Secrets Behind Vegetation Control on Snail Fever

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Oncomelania (Oncomelania hupensis), a dioecian, ovoviviparous, and amphibious snail, is the sole intermediate host of Schistosoma japonicum, the most wide-spread snail fever in the world. Chemical eliminating the host proved unacceptable for there was severe contamination to water and soil. The river beaches and the delta areas of five provinces in the middle and lower reaches of Yangtze River in China provide the most favorable habitats for Oncomelania. Our studies have revealed that the occurrence of ...

  2. Snail levels control the migration mechanism of mesenchymal tumor cells.

    Science.gov (United States)

    Belgiovine, Cristina; Chiesa, Giulio; Chiodi, Ilaria; Frapolli, Roberta; Bonezzi, Katiuscia; Taraboletti, Giulia; D'Incalci, Maurizio; Mondello, Chiara

    2016-07-01

    Cancer cells use two major types of movement: Mesenchymal, which is typical of cells of mesenchymal origin and depends on matrix metalloproteinase (MMP) activity, and amoeboid, which is characteristic of cells with a rounded shape and relies on the activity of Rho-associated kinase (ROCK). The present authors previously demonstrated that, during neoplastic transformation, telomerase-immortalized human fibroblasts (cen3tel cells) acquired a ROCK-dependent/MMP independent mechanism of invasion, mediated by the downregulation of the ROCK cellular inhibitor Round (Rnd)3/RhoE. In the present study, cen3tel transformation was also demonstrated to be paralleled by downregulation of Snail, a major determinant of the mesenchymal movement. To test whether Snail levels could determine the type of movement adopted by mesenchymal tumor cells, Snail was ectopically expressed in tumorigenic cells. It was observed that ectopic Snail did not increase the levels of typical mesenchymal markers, but induced cells to adopt an MMP-dependent mechanism of invasion. In cells expressing ectopic Snail, invasion became sensitive to the MMP inhibitor Ro 28-2653 and insensitive to the ROCK inhibitor Y27632, suggesting that, once induced by Snail, the mesenchymal movement prevails over the amoeboid one. Snail-expressing cells had a more aggressive behavior in vivo, and exhibited increased tumor growth rate and metastatic ability. These results confirm the high plasticity of cancer cells, which can adopt different types of movement in response to changes in the expression of specific genes. Furthermore, the present findings indicate that Rnd3 and Snail are possible regulators of the type of invasion mechanism adopted by mesenchymal tumor cells.

  3. Toxicity of Metals to a Freshwater Snail, Melanoides tuberculata

    Directory of Open Access Journals (Sweden)

    M. Shuhaimi-Othman

    2012-01-01

    Full Text Available Adult freshwater snails Melanoides tuberculata (Gastropod, Thiaridae were exposed for a four-day period in laboratory conditions to a range of copper (Cu, cadmium (Cd, zinc (Zn, lead (Pb, nickel (Ni, iron (Fe, aluminium (Al, and manganese (Mn concentrations. Mortality was assessed and median lethal times (LT50 and concentrations (LC50 were calculated. LT50 and LC50 increased with the decrease in mean exposure concentrations and times, respectively, for all metals. The LC50 values for the 96-hour exposures to Cu, Cd, Zn, Pb, Ni, Fe, Al, and Mn were 0.14, 1.49, 3.90, 6.82, 8.46, 8.49, 68.23, and 45.59 mg L−1, respectively. Cu was the most toxic metal to M. tuberculata, followed by Cd, Zn, Pb, Ni, Fe, Mn, and Al (Cu > Cd > Zn > Pb > Ni > Fe > Mn > Al. Metals bioconcentration in M. tuberculata increases with exposure to increasing concentrations and Cu has the highest accumulation (concentration factor in the soft tissues. A comparison of LC50 values for metals for this species with those for other freshwater gastropods reveals that M. tuberculata is equally sensitive to metals.

  4. The invasive Chinese mystery snail Bellamya chinensis (Gastropoda: Viviparidae expands its European range to Belgium

    Directory of Open Access Journals (Sweden)

    Van den Neucker Tom

    2017-01-01

    Full Text Available In this paper we report the first Belgian records of the invasive Chinese mystery snail Bellamya chinensis. A walkover-survey along the Laak, a small lowland river, yielded a total of 20 live B. chinensis. The presence of both juvenile and adult individuals, with a shell height ranging from 16.6 to 47.5 mm, indicates that the species is firmly established. The most probable source of introduction is a nearby garden center that specializes in ornamental fish and plants for garden ponds.

  5. Factors controlling shell carbon isotopic composition of land snail Acusta despecta sieboldiana estimated from lab culturing experiment

    Directory of Open Access Journals (Sweden)

    N. Zhang

    2014-05-01

    Full Text Available The carbon isotopic composition (δ13C of land snail shell carbonate derives from three potential sources: diet, atmospheric CO2, and ingested carbonate (limestone. However, their relative contributions remain unclear. Under various environmental conditions, we cultured one land snail species, Acusta despecta sieboldiana collected from Yokohama, Japan, and confirmed that all of these sources affect shell carbonate δ13C values. Herein, we consider the influences of metabolic rates and temperature on the carbon isotopic composition of the shell carbonate. Based on previous works and on results obtained in this study, a simple but credible framework is presented for discussion of how each source and environmental parameter can affect shell carbonate δ13C values. According to this framework and some reasonable assumptions, we have estimated the contributions of different carbon sources for each snail individual: for cabbage (C3 plant fed groups, the contributions of diet, atmospheric CO2 and ingested limestone respectively vary as 66–80%, 16–24%, and 0–13%. For corn (C4 plant fed groups, because of the possible food stress (lower consumption ability of C4 plant, the values vary respectively as 56–64%, 18–20%, and 16–26%. Moreover, we present new evidence that snails have discrimination to choose C3 and C4 plants as food. Therefore, we suggest that food preferences must be considered adequately when applying δ13C in paleo-environment studies. Finally, we inferred that, during egg laying and hatching of our cultured snails, carbon isotope fractionation is controlled only by the isotopic exchange of the calcite–HCO3−–aragonite equilibrium.

  6. Factors controlling shell carbon isotopic composition of land snail Acusta despecta sieboldiana estimated from lab culturing experiment

    Science.gov (United States)

    Zhang, N.; Yamada, K.; Suzuki, N.; Yoshida, N.

    2014-05-01

    The carbon isotopic composition (δ13C) of land snail shell carbonate derives from three potential sources: diet, atmospheric CO2, and ingested carbonate (limestone). However, their relative contributions remain unclear. Under various environmental conditions, we cultured one land snail species, Acusta despecta sieboldiana collected from Yokohama, Japan, and confirmed that all of these sources affect shell carbonate δ13C values. Herein, we consider the influences of metabolic rates and temperature on the carbon isotopic composition of the shell carbonate. Based on previous works and on results obtained in this study, a simple but credible framework is presented for discussion of how each source and environmental parameter can affect shell carbonate δ13C values. According to this framework and some reasonable assumptions, we have estimated the contributions of different carbon sources for each snail individual: for cabbage (C3 plant) fed groups, the contributions of diet, atmospheric CO2 and ingested limestone respectively vary as 66-80%, 16-24%, and 0-13%. For corn (C4 plant) fed groups, because of the possible food stress (lower consumption ability of C4 plant), the values vary respectively as 56-64%, 18-20%, and 16-26%. Moreover, we present new evidence that snails have discrimination to choose C3 and C4 plants as food. Therefore, we suggest that food preferences must be considered adequately when applying δ13C in paleo-environment studies. Finally, we inferred that, during egg laying and hatching of our cultured snails, carbon isotope fractionation is controlled only by the isotopic exchange of the calcite-HCO3--aragonite equilibrium.

  7. Pedicularia vanderlandi spec. nov., a symbiotic snail (Caenogastropoda: Ovulidae) on the hydrocoral Distichopora vervoorti Cairns & Hoeksema, 1998 (Hydrozoa: Stylasteridae), from Bali, Indonesia

    NARCIS (Netherlands)

    Goud, J.; Hoeksema, B.W.

    2001-01-01

    A new species of ovulid gastropod is described from Bali as Pedicularia vanderlandi spec. nov. It was predominantly found in shallow water on the stylasterid hydrocoral Distichopora vervoorti Cairns & Hoeksema, 1998. The snails are compared with type specimens of congeneric taxa and with material of

  8. Modelling spatial distribution of snails transmitting parasitic worms with importance to human and animal health and analysis of distributional changes in relation to climate

    DEFF Research Database (Denmark)

    Pedersen, Ulrik Bo; Midzi, Nicholas; Mduluza, Takafira;

    2014-01-01

    of a maximum entropy algorithm (Maxent). Two snail observation datasets from Zimbabwe, from 1988 and 2012, were compared in terms of geospatial distribution and potential distributional change over this 24-year period investigated. Climate data, from the two years were identified and used in a species...

  9. The occurrence of the rat lungworm, Angiostrongylus cantonensis, in nonindigenous snails in the Gulf of Mexico region of the United States

    Science.gov (United States)

    Teem, John L.; Qvarnstrom, Yvonne; Bishop, Henry S.; da Silva, Alexandre J.; Carter, Jacoby; White-McLean, Jodi; Smith, Trevor

    2013-01-01

    Nonindigenous apple snails, Pomacea maculata (formerly Pomacea insularum), are currently spreading rapidly through the southeastern United States. This mollusk serves as an intermediate host of the rat lungworm parasite (Angiostrongylus cantonensis), which can cause eosinophilic meningitis in humans who consume infected mollusks. A PCR-based detection assay was used to test nonindigenous apple snails for the rat lungworm parasite in Louisiana, Texas, Mississippi, and Florida. Only apple snails obtained from the New Orleans, Louisiana, area tested positive for the parasite. These results provide the first evidence that Angiostrongylus cantonensis does occur in nonindigenous apple snails in the southeastern United States. Additionally, Angiostrongylus cantonensis was identified in the terrestrial species Achatina fulica in Miami, Florida, indicating that rat lungworm is now established in Florida as well as Louisiana. Although the study suggests that the rat lungworm is not widespread in the Gulf States region, the infected snail population could still pose a risk to human health and facilitate the spread of the parasite to new areas.

  10. Molluscicidal activity of chlorophyll extraction against the freshwater snails

    Institute of Scientific and Technical Information of China (English)

    Mona Said Mahmoud; Peter Richter; Hatem Abdel Mawgoud Shalaby; Omnia Mohamed Kandil; Donat-Peter Hder

    2013-01-01

    Objective: To evaluate the molluscicidal activity of chlorophyll extract as a photodynamic substance against the snails Lymnaea stagnalis, Biomphalaria spp. and Physa marmorata.Methods:Chlorophyllin was extracted from deep-frozen spinach. Snails were incubated in chlorophyllin containing water with 2.5, 5.0, 10.0 and 15.0 µg/mL. All samples were kept in darkness overnight for incubation. After incubation, three samples were irradiated with simulated solar radiation for 3 h. After irradiation, the vitality of the organisms was determined. Results: The photodynamically active chlorophyllin, at low concentrations, was able to kill snails within a few hours under exposure of solar radiation. Besides, it had a killing effect by about 70%and 100% on the snails’ eggs and the newly hatched snails, respectively, after 3 h exposure to solar radiation.Conclusion:The derivates of chlorophyll was a very interesting substance for photodynamic freshwater snail control. Hence, it might be a promising and cheap new strategy which probably had the potential to replace the synthetic molluscicides for snail control.

  11. Molluscicidal activity of chlorophyll extraction against the freshwater snails

    Directory of Open Access Journals (Sweden)

    Mona Said Mahmoud

    2013-09-01

    Full Text Available Objective: To evaluate the molluscicidal activity of chlorophyll extract as a photodynamic substance against the snails Lymnaea stagnalis, Biomphalaria spp. and Physa marmorata. Methods: Chlorophyllin was extracted from deep-frozen spinach. Snails were incubated in chlorophyllin containing water with 2.5, 5.0, 10.0 and 15.0 µg/mL. All samples were kept in darkness overnight for incubation. After incubation, three samples were irradiated with simulated solar radiation for 3 h. After irradiation, the vitality of the organisms was determined. Results: The photodynamically active chlorophyllin, at low concentrations, was able to kill snails within a few hours under exposure of solar radiation. Besides, it had a killing effect by about 70% and 100% on the snails’ eggs and the newly hatched snails, respectively, after 3 h exposure to solar radiation. Conclusion: The derivates of chlorophyll was a very interesting substance for photodynamic freshwater snail control. Hence, it might be a promising and cheap new strategy which probably had the potential to replace the synthetic molluscicides for snail control.

  12. Crawling beneath the free surface: Water snail locomotion

    CERN Document Server

    Lee, Sungyon; Hosoi, A E; Lauga, Eric

    2008-01-01

    Land snails move via adhesive locomotion. Through muscular contraction and expansion of their foot, they transmit waves of shear stress through a thin layer of mucus onto a solid substrate. Since a free surface cannot support shear stress, adhesive locomotion is not a viable propulsion mechanism for water snails that travel inverted beneath the free surface. Nevertheless, the motion of the freshwater snail, Sorbeoconcha physidae, is reminiscent of that of its terrestrial counterparts, being generated by the undulation of the snail foot that is separated from the free surface by a thin layer of mucus. Here, a lubrication model is used to describe the mucus flow in the limit of small amplitude interfacial deformations. By assuming the shape of the snail foot to be a traveling sine wave and the mucus to be Newtonian, an evolution equation for the interface shape is obtained and the resulting propulsive force on the snail is calculated. This propulsive force is found to be non-zero for moderate values of Capillar...

  13. Fascioliasis transmission by Lymnaea neotropica confirmed by nuclear rDNA and mtDNA sequencing in Argentina.

    Science.gov (United States)

    Mera y Sierra, Roberto; Artigas, Patricio; Cuervo, Pablo; Deis, Erika; Sidoti, Laura; Mas-Coma, Santiago; Bargues, Maria Dolores

    2009-12-03

    Fascioliasis is widespread in livestock in Argentina. Among activities included in a long-term initiative to ascertain which are the fascioliasis areas of most concern, studies were performed in a recreational farm, including liver fluke infection in different domestic animal species, classification of the lymnaeid vector and verification of natural transmission of fascioliasis by identification of the intramolluscan trematode larval stages found in naturally infected snails. The high prevalences in the domestic animals appeared related to only one lymnaeid species present. Lymnaeid and trematode classification was verified by means of nuclear ribosomal DNA and mitochondrial DNA marker sequencing. Complete sequences of 18S rRNA gene and rDNA ITS-2 and ITS-1, and a fragment of the mtDNA cox1 gene demonstrate that the Argentinian lymnaeid belongs to the species Lymnaea neotropica. Redial larval stages found in a L. neotropica specimen were ascribed to Fasciola hepatica after analysis of the complete ITS-1 sequence. The finding of L. neotropica is the first of this lymnaeid species not only in Argentina but also in Southern Cone countries. The total absence of nucleotide differences between the sequences of specimens from Argentina and the specimens from the Peruvian type locality at the levels of rDNA 18S, ITS-2 and ITS-1, and the only one mutation at the mtDNA cox1 gene suggest a very recent spread. The ecological characteristics of this lymnaeid, living in small, superficial water collections frequented by livestock, suggest that it may be carried from one place to another by remaining in dried mud stuck to the feet of transported animals. The presence of L. neotropica adds pronounced complexity to the transmission and epidemiology of fascioliasis in Argentina, due to the great difficulties in distinguishing, by traditional malacological methods, between the three similar lymnaeid species of the controversial Galba/Fossaria group present in this country: L. viatrix

  14. Predator-prey interactions between shell-boring beetle larvae and rock-dwelling land snails.

    Directory of Open Access Journals (Sweden)

    Els Baalbergen

    Full Text Available Drilus beetle larvae (Coleoptera: Elateridae are specialized predators of land snails. Here, we describe various aspects of the predator-prey interactions between multiple Drilus species attacking multiple Albinaria (Gastropoda: Clausiliidae species in Greece. We observe that Drilus species may be facultative or obligate Albinaria-specialists. We map geographically varying predation rates in Crete, where on average 24% of empty shells carry fatal Drilus bore holes. We also provide first-hand observations and video-footage of prey entry and exit strategies of the Drilus larvae, and evaluate the potential mutual evolutionary impacts. We find limited evidence for an effect of shell features and snail behavioral traits on inter- and intra-specifically differing predation rates. We also find that Drilus predators adjust their predation behavior based on specific shell traits of the prey. In conclusion, we suggest that, with these baseline data, this interesting predator-prey system will be available for further, detailed more evolutionary ecology studies.

  15. Acidic, neutral and alkaline forest ponds as a landscape element affecting the biodiversity of freshwater snails

    Science.gov (United States)

    Spyra, Aneta

    2017-10-01

    In recent years, the number of areas remaining under the influence of acidity has increased. At all levels of ecosystems, biodiversity decreases with acidification, due to the elimination of species that are most sensitive to low pH. Forest ponds belong to a specific group that varied in location, a huge amount of leaf litter, and isolation from other aquatic environments. They are crucial in the industrial landscape with well-developed industry and human activity. The aim was to investigate the relative importance of water chemistry in explaining snail assemblage compositions and species richness in forest ponds of contrasting pH. Patterns in gastropod communities were determined from an analysis in 26 forest ponds with multivariate gradient analysis. Ponds ranged in a base mean pH from 3.0 to 9.0. pH has been found to be an important factor influencing gastropod fauna. Neutral ponds support diverse communities, typical of small water bodies. In two acidic pond types, snail fauna was different. Among the species characteristic for acidic ponds (pH Current knowledge of pH-associated changes in aquatic ecosystems is still incomplete because anthropogenic acidification is a recent phenomenon. It is extremely important in forest habitats, since they react more intensively to climatic factors and are often used in landscape management and planning.

  16. Origin and diversification of the endemic Hawaiian tree snails (Achatinellidae: Achatinellinae) based on molecular evidence.

    Science.gov (United States)

    Holland, Brenden S; Hadfield, Michael G

    2004-08-01

    Tree snails of the endemic subfamily Achatinellinae comprise a diverse and important component of the Hawaiian fauna. In recent decades anthropogenic impacts have resulted in devastating extinction rates in Hawaiian tree snails. To address long-standing biogeographic, systematic, and evolutionary questions we used cytochrome c oxidase subunit I (COI) gene sequences to reconstruct the phylogeny of 23 extant species spanning the range of the subfamily from five Hawaiian Islands. To investigate family-level relationships, data were analyzed from 11 terrestrial pulmonate families. Although nodal support for monophyly of the endemic Pacific family Achatinellidae and endemic Hawaiian subfamily Achatinellinae was strong, bifurcation order among deeper ingroup nodes was not well-supported by bootstrap resampling. We hypothesize that lineage extinction and rapidity of lineage formation may have rendered evolutionary reconstruction difficult using a standard phylogenetic approach. Use of an optimized evolutionary model, however, improved resolution and recovered three main clades. The diversification pattern inferred contradicts the traditional biogeographic hypothesis of a Maui origin of the achatinelline lineage. Taxa comprising the basal ingroup clade (Achatinella spp.) and seeding lineages for subsequent clades originated on O'ahu. Therefore it appears that the ancestral colonizing species of achatinellines arrived first on O'ahu from an unknown source, and that O'ahu is the Hawaiian origin of the subfamily. Species previously defined by morphological criteria were generally found to be phylogenetically distinct, and the overall colonization pattern follows the island-age progression rule with several instances of generic polyphyly and back-colonization.

  17. Potential schistosome-vector snails and associated trematodes in ricefields of Corrients province, Argentina: preliminary results

    Directory of Open Access Journals (Sweden)

    Alejandra Rumi

    1990-09-01

    Full Text Available Considering the possibility of introduction of schistosomiasis mansoni into Argentina as a consequence of dam construction on the Rio De La Plata basin, preliminary studies have been carried out on agrosystems such as ricefields in Corrientes province with the following purposes: 1 to survey and estimate the relative abundance of planorbids and identify potential vector species; 2 to identify environmental factors capable of influencing Biomphalaria population dynamics; and 3 to find out snail-parasite associations and estimate snail infection rates in order to detect possible competitive interactions between larval stages of native trematodes that could be used in biological control of Schistosoma mansoni. Three potential schistosome vectors were detected in ricefields, namely Biomphalaria straminea, B. tenagophila and B. peregrina, although B. orbignyi, a species refractory to infection with S. mansoni, proved the most frequent and abundant. Positive correlations (P0.05 was found in total iron, phosphates (SRP, pH and soil granulometry. Echinocercariae developed from rediae and belonging to Petasiger sp., Paryphostomum sp., and other undetermined species were found.

  18. Is Galba schirazensis (Mollusca, Gastropoda an intermediate host of Fasciola hepatica (Trematoda, Digenea in Ecuador?

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    Caron Yannick

    2017-01-01

    Full Text Available Fasciolosis is a widely distributed disease in livestock in South America but knowledge about the epidemiology and the intermediate hosts is relatively scarce in Ecuador. For three months, lymnaeid snails were sampled (n = 1482 in Pichincha Province at two sites located in a highly endemic area. Snails were identified (based on morphology and ITS-2 sequences and the infection status was established through microscopic dissection and a multiplex polymerase chain reaction (PCR-based technique. Techniques based on morphology were not useful to accurately name the collected snail species. Comparison with available DNA sequences showed that a single snail species was collected, Galba schirazensis. Live rediae were observed in 1.75% (26/1482 and Fasciola sp. DNA was detected in 6% (89/1482 of collected snails. The COX-1 region permitted identification of the parasite as Fasciola hepatica. The relative sensitivity and specificity of the microscope study, compared to PCR results, were 25.84% and 99.78%, respectively. The mean size of the snails recorded positive for F. hepatica through crushing and microscopy was significantly higher than the mean size of negative snails, but there was no such difference in PCR-positive snails. The role of G. schirazensis as an intermediate host of F. hepatica in Ecuador is discussed and the hypothesis of an adaptation of the parasite to this invasive snail is proposed. For the first time, an epidemiological survey based on molecular biology-based techniques assessed the possible role of lymnaeid snails in the epidemiology of fasciolosis in Ecuador.

  19. Is Galba schirazensis (Mollusca, Gastropoda) an intermediate host of Fasciola hepatica (Trematoda, Digenea) in Ecuador?

    Science.gov (United States)

    Caron, Yannick; Celi-Erazo, Maritza; Hurtrez-Boussès, Sylvie; Lounnas, Mannon; Pointier, Jean-Pierre; Saegerman, Claude; Losson, Bertrand; Benítez-Ortíz, Washington

    2017-01-01

    Fasciolosis is a widely distributed disease in livestock in South America but knowledge about the epidemiology and the intermediate hosts is relatively scarce in Ecuador. For three months, lymnaeid snails were sampled (n = 1482) in Pichincha Province at two sites located in a highly endemic area. Snails were identified (based on morphology and ITS-2 sequences) and the infection status was established through microscopic dissection and a multiplex polymerase chain reaction (PCR)-based technique. Techniques based on morphology were not useful to accurately name the collected snail species. Comparison with available DNA sequences showed that a single snail species was collected, Galba schirazensis. Live rediae were observed in 1.75% (26/1482) and Fasciola sp. DNA was detected in 6% (89/1482) of collected snails. The COX-1 region permitted identification of the parasite as Fasciola hepatica. The relative sensitivity and specificity of the microscope study, compared to PCR results, were 25.84% and 99.78%, respectively. The mean size of the snails recorded positive for F. hepatica through crushing and microscopy was significantly higher than the mean size of negative snails, but there was no such difference in PCR-positive snails. The role of G. schirazensis as an intermediate host of F. hepatica in Ecuador is discussed and the hypothesis of an adaptation of the parasite to this invasive snail is proposed. For the first time, an epidemiological survey based on molecular biology-based techniques assessed the possible role of lymnaeid snails in the epidemiology of fasciolosis in Ecuador. © Y. Caron et al., published by EDP Sciences, 2017.

  20. Metal-metallothioneins like proteins investigation by heteroatom-tagged proteomics in two different snails as possible sentinel organisms of metal contamination in freshwater ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Franca Maltez, Heloisa [Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Julian Claveria 8, 33006 Oviedo (Spain); Villanueva Tagle, Margarita [Faculty of Chemistry, University of La Habana (Cuba); Rosario Fernandez de la Campa, Maria del [Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Julian Claveria 8, 33006 Oviedo (Spain); Sanz-Medel, Alfredo, E-mail: asm@uniovi.es [Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Julian Claveria 8, 33006 Oviedo (Spain)

    2009-09-21

    Metal speciation analysis in MLPs was carried out in two snails, Marisa cornuarietis and Pomacea bridgesi, in order to investigate them as possible sentinel organisms of heavy metal contamination. To carry out this study snails born in a non-contaminated environment were divided into two groups: a control group and a contaminated one with cadmium administered for 40 days. Subsequently, we investigated the speciation of the induced MLPs in exposed animals in relation to controls. In order to obtain the MLP fraction, cytosols from both snail species where subjected to size-exclusion fractionation, monitoring on-line the metal signal (Cd, Cu and Zn) by ICP-MS while protein elution was followed by on-line UV detection. MLP fraction was then separated by anion-exchange (AE)-FPLC using optimal chromatographic conditions for the separation of the different MLP isoforms in both snail species. Specific detection of separated metalloforms was carried out again by the hyphenation of the AE chromatographic system with ICP-MS. The determination of the amount of metal bound to MLPs was carried out by post-column isotope dilution analysis ICP-MS, finding that the snail M. cornuarietis accumulated higher concentrations of cadmium than P. bridgesi. Thus this first snail could therefore be a better candidate sentinel organism of pollution in natural waters. Identification and characterization of the isoforms separated in M. cornuarietis was carried out for the entire or intact isoforms by MALDI-TOF and then conventional triptic digestion was also carried out to identify the nature of the formed peptides. The presence identification of a MLP isoform of relatively low molecular weight in M. cornuarietis is reported.

  1. Scientific Opinion on the environmental risk assessment of the apple snail for the EU

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Plant Health (PLH

    2014-04-01

    Full Text Available At EFSA’s request, the Plant Health Panel (PLH performed an environmental risk assessment (ERA of the apple snail for the EU and validated the ERA approach presented in the PLH ERA guidance document. Improvements and suggestions for simplification of the ERA are provided. One service-providing unit—shallow fresh water areas—was identified for this ERA. The effects of resistance, resilience and management on snail population dynamics in the short (5 years and the long term (30 years were estimated. In line with the PLH ERA guidance rating system, expert judgement was used to evaluate separately the impacts on (i ecosystem traits, (ii ecosystem services and (iii biodiversity components. Snail biomass values were predicted to be higher in the short term than in the long term. For ecosystem services, moderate risk was estimated for genetic resources, climate regulation, pest and disease regulation and pollination in both the short and long term; for food, risk was assessed as moderate in the short term and major in the long term; for water and erosion regulation, risk was assessed as major both in the short term and in the long term; for fresh water, risk was assessed as massive both in the short term and in the long term; and for nutrient cycling and photosynthesis and primary production of macrophytes, risk was assessed as massive in the short term and as major in the long term. For biodiversity components, risk for genetic diversity and native species diversity was estimated as major in both the short and the long term; risk for native habitats was assessed massive in the short term and major in the long term; and for threatened species and habitats of high conservation value, risk was determined as massive in both the short and the long term.

  2. Uranium exposure to the tropical duckweed Lemna aequinoctialis and pulmonate snail Amerianna cumingi: fate and toxicity.

    Science.gov (United States)

    Hogan, Alicia C; van Dam, Rick A; Houston, Melanie A; Harford, Andrew J; Nou, Suthidha

    2010-08-01

    The discharge of catchment-management water from the Ranger uranium (U) mine into Magela Creek upstream of the Ramsar-listed Magela Floodplain in Kakadu National Park is an important part of the mine's water-management system. Because U is one of the primary toxicants associated with this water, a receiving-water trigger value (TV), based on chronic toxicity data from five local native species, was derived for U. To strengthen the data set underpinning the derivation of the TV, the chronic toxicity of U to two additional tropical freshwater species, duckweed Lemna aequinoctialis (96-hour growth rate), and pulmonate gastropod, Amerianna cumingi (96-hour reproduction), was determined. The fate of U within the test systems was an important component of the study because analysis of U concentrations during the snail tests indicated that a substantial proportion of U (approximately 25%) was being lost from the test solutions when integrated during the entire test duration. Analysis of the snails and their food for U indicated that only a small proportion that was lost from solution was being taken up by the snails. Therefore, the majority of U that was lost was considered unavailable to the snails, and thus the exposure concentrations used to calculate the toxicity estimates were adjusted downward. Integrating the loss of U from the L. aequinoctialis test solutions over time showed that only a small proportion (6% to 13%) was lost during the test: Of that, almost half (2-5%) was taken up by the plants (constituting exposure). Uranium was only moderately toxic to L. aequinoctialis, with no observed-effect concentrations, lowest observed-effect concentrations, and inhibition concentrations causing 10% and 50% effects (IC10 and IC50) values of 226, 404, 207, and 1435 microg/l, respectively. A. cumingi was found to be more sensitive to U than L. aequinoctialis, with NOEC, LOEC, IC10, and IC50 values of 60, 61, 15, and 278 microg/l, respectively. The data for these two

  3. Characterisation of Lymnaea cubensis, L. viatrix and L. neotropica n. sp., the main vectors of Fasciola hepatica in Latin America, by analysis of their ribosomal and mitochondrial DNA.

    Science.gov (United States)

    Bargues, M D; Artigas, P; Mera Y Sierra, R L; Pointier, J P; Mas-Coma, S

    2007-10-01

    Although, in the endemic areas throughout the world, human fascioliasis presents varying patterns in its epidemiology, the species of lymnaeid snail that act as intermediate hosts and vectors are always crucial in the transmission of the causative parasites. Species in the Galba/Fossaria group of snails, such as Lymnaea cubensis, L. viatrix var. A ventricosa, L. viatrix var. B elongata and Galba truncatula, appear to be frequently involved in the transmission of Fasciola hepatica in Central and South America, although specific classification within this morphologically and anatomically confusing group is often very difficult. To explore the potential use of molecular analyses in the identification of vector snails, regions of the ribosomal DNA - the small subunit (18S) gene and internal transcribed spacers (ITS-2 and ITS-1) - and of the mitochondrial DNA - the cytochrome c oxidase subunit I (COI) - of wild-caught lymnaeid snails of L. cubensis, L. viatrix var. A ventricosa, L. viatrix var. B elongata and G. truncatula have been sequenced. The samples of the Latin American species included specimens from the respective type localities. The genetic distances observed and the results of phylogenetic analyses demonstrate that two different species exist within L. viatrix. Lymnaea neotropica n. sp. (=L. viatrix var. B elongata) is here proposed for specimens from Lima, Peru, and is differentiated from L. viatrix (=L. viatrix var. A ventricosa), L. cubensis and G. truncatula. The data collected on the 18S ribosomal-RNA gene indicate that the snails investigated may cover more than one supraspecific taxon. The ITS-2, ITS-1 and COI nucleotide sequences are clearly useful markers for the differentiation of these morpho-anatomically similar lymnaeid species. The numerous microsatellite repeats found within ITS-2 are potential tools for differentiation at population level.

  4. Functional changes in the snail statocyst system elicited by microgravity.

    Directory of Open Access Journals (Sweden)

    Pavel M Balaban

    Full Text Available BACKGROUND: The mollusk statocyst is a mechanosensing organ detecting the animal's orientation with respect to gravity. This system has clear similarities to its vertebrate counterparts: a weight-lending mass, an epithelial layer containing small supporting cells and the large sensory hair cells, and an output eliciting compensatory body reflexes to perturbations. METHODOLOGY/PRINCIPAL FINDINGS: In terrestrial gastropod snail we studied the impact of 16- (Foton M-2 and 12-day (Foton M-3 exposure to microgravity in unmanned orbital missions on: (i the whole animal behavior (Helix lucorum L., (ii the statoreceptor responses to tilt in an isolated neural preparation (Helix lucorum L., and (iii the differential expression of the Helix pedal peptide (HPep and the tetrapeptide FMRFamide genes in neural structures (Helix aspersa L.. Experiments were performed 13-42 hours after return to Earth. Latency of body re-orientation to sudden 90° head-down pitch was significantly reduced in postflight snails indicating an enhanced negative gravitaxis response. Statoreceptor responses to tilt in postflight snails were independent of motion direction, in contrast to a directional preference observed in control animals. Positive relation between tilt velocity and firing rate was observed in both control and postflight snails, but the response magnitude was significantly larger in postflight snails indicating an enhanced sensitivity to acceleration. A significant increase in mRNA expression of the gene encoding HPep, a peptide linked to ciliary beating, in statoreceptors was observed in postflight snails; no differential expression of the gene encoding FMRFamide, a possible neurotransmission modulator, was observed. CONCLUSIONS/SIGNIFICANCE: Upregulation of statocyst function in snails following microgravity exposure parallels that observed in vertebrates suggesting fundamental principles underlie gravi-sensing and the organism's ability to adapt to gravity

  5. Functional changes in the snail statocyst system elicited by microgravity.

    Science.gov (United States)

    Balaban, Pavel M; Malyshev, Aleksey Y; Ierusalimsky, Victor N; Aseyev, Nikolay; Korshunova, Tania A; Bravarenko, Natasha I; Lemak, M S; Roshchin, Matvey; Zakharov, Igor S; Popova, Yekaterina; Boyle, Richard

    2011-03-29

    The mollusk statocyst is a mechanosensing organ detecting the animal's orientation with respect to gravity. This system has clear similarities to its vertebrate counterparts: a weight-lending mass, an epithelial layer containing small supporting cells and the large sensory hair cells, and an output eliciting compensatory body reflexes to perturbations. In terrestrial gastropod snail we studied the impact of 16- (Foton M-2) and 12-day (Foton M-3) exposure to microgravity in unmanned orbital missions on: (i) the whole animal behavior (Helix lucorum L.), (ii) the statoreceptor responses to tilt in an isolated neural preparation (Helix lucorum L.), and (iii) the differential expression of the Helix pedal peptide (HPep) and the tetrapeptide FMRFamide genes in neural structures (Helix aspersa L.). Experiments were performed 13-42 hours after return to Earth. Latency of body re-orientation to sudden 90° head-down pitch was significantly reduced in postflight snails indicating an enhanced negative gravitaxis response. Statoreceptor responses to tilt in postflight snails were independent of motion direction, in contrast to a directional preference observed in control animals. Positive relation between tilt velocity and firing rate was observed in both control and postflight snails, but the response magnitude was significantly larger in postflight snails indicating an enhanced sensitivity to acceleration. A significant increase in mRNA expression of the gene encoding HPep, a peptide linked to ciliary beating, in statoreceptors was observed in postflight snails; no differential expression of the gene encoding FMRFamide, a possible neurotransmission modulator, was observed. Upregulation of statocyst function in snails following microgravity exposure parallels that observed in vertebrates suggesting fundamental principles underlie gravi-sensing and the organism's ability to adapt to gravity changes. This simple animal model offers the possibility to describe general

  6. IMPROVEMENT IN LABORATORY REARING OF IMMATURE STAGES OF SNAIL-KILLING FLY SEPEDON SPHEGEA (FABRICIUS AND THEIR SURVIVAL (INSECTA, DIPTERA, SCIOMYZIDAE

    Directory of Open Access Journals (Sweden)

    S.Tirgari

    1978-12-01

    Full Text Available The biology of immature stages of S.sphegea and different techniques for their laboratory rearing has been studied during the past five years (1972-77. This fly is one of the 18 Iranian species of snail-killing flies which is dominant in the focus area of schistosomiasis (Khuzestan Province in the south-west of Iran. The following procedures improved appreciably our laboratory rearin-technics and greatly reduced larval mortality: 1- Large number of fresh aquatic snails required for the progress of this study has been obtained at the entrances of the traditional under ground water canals (Ghanat in Teheran. These canals are almost permanent sources of snails because their water temperatures are rather constant through out the year and the water is by far protected from the surface pollution. In other cases, fresh snail was brought from distant swamp and rice fields. Attempts to maintain and to rear live aquatic snails, in large container equipped with aeration pump were not successful due to infection with coli form bacteria. Although the infected snails did not show any biological ill symptoms, could cause heavy mortality among larvae of flies. 2- Fly larvae were reared in plastic container of 28×32 cm. containing 7 to 8 liters of water (7 to 8 cm.depth. Eight to 12 laboratory vials filled with water were placed vertically in several rows in each container to secure uniform distribution of both snails and fly larvae. Fresh and dried leaves of lettuce were used to feed the snails. 3- Dead snails and their shells were picked out by forceps and half of the volume of water of all containers was drained from the bottom by siphoning every two days. 4- The surface pollution of water in the containers, which caused high mortality in different stages of larval development, was removed every four to five days by strips of blotting paper. The oily missed pollution on the water-surface was mostly due to dead snails, rotten leaves of lettuce and to a lesser

  7. Development and validation of an OECD reproductive toxicity test guideline with the pond snail Lymnaea stagnalis (Mollusca, Gastropoda).

    Science.gov (United States)

    Ducrot, Virginie; Askem, Clare; Azam, Didier; Brettschneider, Denise; Brown, Rebecca; Charles, Sandrine; Coke, Maïra; Collinet, Marc; Delignette-Muller, Marie-Laure; Forfait-Dubuc, Carole; Holbech, Henrik; Hutchinson, Thomas; Jach, Arne; Kinnberg, Karin L; Lacoste, Cédric; Le Page, Gareth; Matthiessen, Peter; Oehlmann, Jörg; Rice, Lynsey; Roberts, Edward; Ruppert, Katharina; Davis, Jessica Elphinstone; Veauvy, Clemence; Weltje, Lennart; Wortham, Ruth; Lagadic, Laurent

    2014-12-01

    The OECD test guideline development program has been extended in 2011 to establish a partial life-cycle protocol for assessing the reproductive toxicity of chemicals to several mollusk species, including the great pond snail Lymnaea stagnalis. In this paper, we summarize the standard draft protocol for a reproduction test with this species, and present inter-comparison results obtained in a 56-day prevalidation ring-test using this protocol. Seven European laboratories performed semi-static tests with cultured snails of the strain Renilys® exposed to nominal concentrations of cadmium chloride (from 53 to 608μgCdL(-1)). Cd concentrations in test solutions were analytically determined to confirm accuracy in the metal exposure concentrations in all laboratories. Physico-chemical and biological validity criteria (namely dissolved oxygen content >60% ASV, water temperature 20±1°C, control snail survival >80% and control snail fecundity >8 egg-masses per snail over the test period) were met in all laboratories which consistently demonstrated the reproductive toxicity of Cd in snails using the proposed draft protocol. Effect concentrations for fecundity after 56days were reproducible between laboratories (68

  8. Screening and Validation of Highly-Efficient Insecticidal Conotoxins from a Transcriptome-Based Dataset of Chinese Tubular Cone Snail

    Directory of Open Access Journals (Sweden)

    Bingmiao Gao

    2017-07-01

    Full Text Available Most previous studies have focused on analgesic and anti-cancer activities for the conotoxins identified from piscivorous and molluscivorous cone snails, but little attention has been devoted to insecticidal activity of conotoxins from the dominant vermivorous species. As a representative vermivorous cone snail, the Chinese tubular cone snail (Conus betulinus is the dominant Conus species inhabiting the South China Sea. We sequenced related venom transcriptomes from C. betulinus using both the next-generation sequencing and traditional Sanger sequencing technologies, and a comprehensive library of 215 conotoxin transcripts was constructed. In our current study, six conotoxins with potential insecticidal activity were screened out from our conotoxin library by homologous search with a reported positive control (alpha-conotoxin ImI from C. imperialis as the query. Subsequently, these conotoxins were synthesized by chemical solid-phase and oxidative folding for further insecticidal activity validation, such as MTT assay, insect bioassay and homology modeling. The final results proved insecticidal activities of our achieved six conotoxins from the transcriptome-based dataset. Interestingly, two of them presented a lot of high insecticidal activity, which supports their usefulness for a trial as insecticides in field investigations. In summary, our present work provides a good example for high throughput development of biological insecticides on basis of the accumulated genomic resources.

  9. Survival and behavior of Chinese mystery snails (Bellamya chinensis) in response to simulated water body drawdowns and extended air exposure

    Science.gov (United States)

    Unstad, Kody M.; Uden, Daniel R.; Allen, Craig R.; Chaine, Noelle M.; Haak, Danielle M.; Kill, Robert A.; Pope, Kevin L.; Stephen, Bruce J.; Wong, Alec

    2013-01-01

    Nonnative invasive mollusks degrade aquatic ecosystems and induce economic losses worldwide. Extended air exposure through water body drawdown is one management action used for control. In North America, the Chinese mystery snail (Bellamya chinensis) is an invasive aquatic snail with an expanding range, but eradication methods for this species are not well documented. We assessed the ability of B. chinensis to survive different durations of air exposure, and observed behavioral responses prior to, during, and following desiccation events. Individual B. chinensis specimens survived air exposure in a laboratory setting for > 9 weeks, and survivorship was greater among adults than juveniles. Several B. chinensis specimens responded to desiccation by sealing their opercula and/or burrowing in mud substrate. Our results indicate that drawdowns alone may not be an effective means of eliminating B. chinensis. This study lays the groundwork for future management research that may determine the effectiveness of drawdowns when combined with factors such as extreme temperatures, predation, or molluscicides.

  10. Mass migration of juvenile Biomphalaria glabrata snails bred under semi-natural conditions

    OpenAIRE

    Frederico Simões Barbosa

    1989-01-01

    For the development of studies on snail interspecific competition special in-door laboratory channels were built. In the all five channels seeded with adult specimens of Biomphalaria glabrata mass migration of juvenile snails outside the water was observed. Most of the migrant snails presented apertural lamellae. Data collected during the period of two years, showed the regression of the migration phenomenon and the disappearance of the lamellate snails.

  11. The freshwater snail lymnaea rubiginosa as an experimental host of Angiostrongylus malaysiensis: a preliminary report.

    Science.gov (United States)

    Dondero, T J; Lim, B L

    1976-03-01

    Preliminary studies have shown that Lymnaea rubiginosa, a common fresh-water snail in Peninsular Malaysia, which is easily colonized and reared in the laboratory, is a capable experimental intermediate host for Angiostrongylus malaysiensis. Overall 73% of the snails tested became infected following 6 hours exposure to infective rat faeces. Higher infection rates, up to 100%, and heavier worm loads, occurred among the larger sized snails. Snail attrition was low except when very heavy worm loads were acquired.

  12. Ringiculid bubble snails recovered as the sister group to sea slugs (Nudipleura)

    Science.gov (United States)

    Kano, Yasunori; Brenzinger, Bastian; Nützel, Alexander; Wilson, Nerida G.; Schrödl, Michael

    2016-08-01

    Euthyneuran gastropods represent one of the most diverse lineages in Mollusca (with over 30,000 species), play significant ecological roles in aquatic and terrestrial environments and affect many aspects of human life. However, our understanding of their evolutionary relationships remains incomplete due to missing data for key phylogenetic lineages. The present study integrates such a neglected, ancient snail family Ringiculidae into a molecular systematics of Euthyneura for the first time, and is supplemented by the first microanatomical data. Surprisingly, both molecular and morphological features present compelling evidence for the common ancestry of ringiculid snails with the highly dissimilar Nudipleura—the most species-rich and well-known taxon of sea slugs (nudibranchs and pleurobranchoids). A new taxon name Ringipleura is proposed here for these long-lost sisters, as one of three major euthyneuran clades with late Palaeozoic origins, along with Acteonacea (Acteonoidea + Rissoelloidea) and Tectipleura (Euopisthobranchia + Panpulmonata). The early Euthyneura are suggested to be at least temporary burrowers with a characteristic ‘bubble’ shell, hypertrophied foot and headshield as exemplified by many extant subtaxa with an infaunal mode of life, while the expansion of the mantle might have triggered the explosive Mesozoic radiation of the clade into diverse ecological niches.

  13. New scope on the relationship between rotifers and Biomphalaria alexandrina snails

    Institute of Scientific and Technical Information of China (English)

    Shereen Farouk Mossallam; Eglal Ibrahim Amer; Iman Fathy Abou-El-Naga

    2013-01-01

    Objective: To investigate the effect of rotifer internalization into snail tissue on the development of schistosomes. Methods:Susceptible laboratory-bred Biomphalaria alexandrina (B. alexandrina) snails were exposed to lab-maintained rotifers; Philodina spp., two weeks before and after being infected with Schistosoma mansoni (S. mansoni) miracidia. The consequent histopathological impact on snail tissues and cercarial biology were investigated before and after emergence from snails. Results:Contamination of B. alexandrina snails with philodina, two weeks before miracidial exposure, was found to hinder the preliminary development of S. mansoni cercariae inside the snail tissues. Furthermore, when snails were contaminated with rotifers two weeks post miracidial exposure; growth of already established cercariae was found to be retarded. The consequent influence of internalized rotifers within the snail tissue was clearly reflected on cercarial emergence, activity and infectivity along the four weeks duration of shedding. In the present study, comparison of snail histopathological findings and altered cercarial biology observed between the experimental and control groups indicated that the rotifers may have affected the levels of snail's energy reservoirs, which eventually was found to have had an adverse impact on reproduction, growth and survival of the parasite within the snail host, coupled with its performance outside the snail. Conclusions:In future biological control strategies of schistosomiasis, ritifers should be considered as a parasitic scourge of humanity.

  14. 75 FR 35424 - Endangered and Threatened Wildlife and Plants; Proposed Reclassification of the Tulotoma Snail...

    Science.gov (United States)

    2010-06-22

    ...; Proposed Reclassification of the Tulotoma Snail From Endangered to Threatened AGENCY: Fish and Wildlife...), propose to reclassify the tulotoma snail (Tulotoma magnifica) from endangered to threatened, under the... no longer correctly reflects the status of this snail. We have documented a substantial...

  15. Effect of pond water depth on snail populations and fish-borne zoonotic trematode transmission in juvenile giant gourami (Osphronemus goramy) aquaculture nurseries.

    Science.gov (United States)

    Thien, P C; Madsen, H; Nga, H T N; Dalsgaard, A; Murrell, K D

    2015-12-01

    Infection with fish-borne zoonotic trematodes (FZT) is an important public health problem in many parts of Southeast Asia. People become infected with FZT when eating raw or undercooked fish that contain the infective stage (metacercariae) of FZT. The parasites require specific freshwater snails as first intermediate host and a variety of fish species, both wild caught and cultured, as second intermediate host. Aquaculture production has grown almost exponentially in SE Asia and in order to produce fish free from FZT metacercariae, it is important to mitigate factors promoting transmission to fish. Here we report results from a cross-sectional study to look at the association between pond depth and infection with FZT in giant gourami nursery ponds. Density of intermediate host snails was positively associated with pond depth (count ratio associated with a 1m increase in pond depth was 10.4 (95% C.L.: 1.61-67.1, p200 fry m(-3)) was associated with lower host snail density (count ratio=0.15) than low stocking density (<100 fry m(3)). Ponds stocked with 100-200 fry m(-3) had snail counts 0.76 (95% C.L.: 0.33-1.75, p n.s.) of those in ponds stocked with fry density of <100 fry m(-3). Since density of intermediate snail hosts was associated with FZT transmission to fish, effort should be taken to reduce snail density prior to stocking the fry, but focus should also be on habitats surrounding ponds as transmission may occur through cercariae produced outside ponds and carried into ponds with water pumped into ponds.

  16. Understanding the regulation of estivation in a freshwater snail through iTRAQ-based comparative proteomics

    KAUST Repository

    Sun, Jin

    2013-11-01

    The apple snail Pomacea canaliculata is a freshwater gastropod with a remarkable ability to withstand seasonal or unpredictable dry conditions by entering estivation. Studies of P. canaliculata using conventional biochemical and the individual gene approaches have revealed the expressional changes of several enzymes and antioxidative genes in response to estivation and arousal. In this study, we applied iTRAQ-coupled two-dimensional LC-MS/MS to identify and quantify the global protein expression during the estivation and arousal of P. canaliculata. A total of 1040 proteins were identified, among which 701 proteins were quantified and compared across four treatments (i.e., control, active snails; short-term estivation, 3 days of exposure to air; prolonged estivation, 30 days of exposure to air; and arousal, 6 h after resubmergence in water) revealing 53 differentially expressed proteins. A comparison of protein expression profiles across treatments indicated that the proteome of this species was very insensitive to initial estivation, with only 9 proteins differentially expressed as compared with the control. Among the 9 proteins, the up-regulations of two immune related proteins indicated the initial immune response to the detection of stress cues. Prolonged estivation resulted in many more differentially expressed proteins (47 compared with short-term estivation treatment), among which 16 were down-regulated and 31 were up-regulated. These differentially expressed proteins have provided the first global picture of a shift in energy usage from glucose to lipid, prevention of protein degradation and elevation of oxidative defense, and production of purine for uric acid production to remove toxic ammonia during prolonged estivation in a freshwater snail. From prolonged estivation to arousal, only 6 proteins changed their expression level, indicating that access to water and food alone is not a necessary condition to reactivate whole-sale protein expression. A

  17. Antioxidant defence and stress protein induction following heat stress in the Mediterranean snail Xeropicta derbentina.

    Science.gov (United States)

    Troschinski, Sandra; Dieterich, Andreas; Krais, Stefanie; Triebskorn, Rita; Köhler, Heinz-R

    2014-12-15

    The Mediterranean snail Xeropicta derbentina (Pulmonata, Hygromiidae), being highly abundant in Southern France, has the need for efficient physiological adaptations to desiccation and over-heating posed by dry and hot environmental conditions. As a consequence of heat, oxidative stress manifests in these organisms, which, in turn, leads to the formation of reactive oxygen species (ROS). In this study, we focused on adaptations at the biochemical level by investigation of antioxidant defences and heat shock protein 70 (Hsp70) induction, both essential mechanisms of the heat stress response. We exposed snails to elevated temperature (25, 38, 40, 43 and 45°C) in the laboratory and measured the activity of the antioxidant enzymes catalase (CAT) and glutathione peroxidase (GPx), determined the Hsp70 level and quantified lipid peroxidation. In general, we found a high constitutive level of CAT activity in all treatments, which may be interpreted as a permanent protection against ROS, i.e. hydrogen peroxide. CAT and GPx showed temperature-dependent activity: CAT activity was significantly increased in response to high temperatures (43 and 45°C), whereas GPx exhibited a significantly increased activity at 40°C, probably in response to high levels of lipid peroxides that occurred in the 38°C treatment. Hsp70 showed a maximum induction at 40°C, followed by a decrease at higher temperatures. Our results reveal that X. derbentina possesses a set of efficient mechanisms to cope with the damaging effects of heat. Furthermore, we demonstrated that, besides the well-documented Hsp70 stress response, antioxidant defence plays a crucial role in the snails' competence to survive extreme temperatures.

  18. Effects of husbandry parameters on the life-history traits of the apple snail, Marisa cornuarietis: effects of temperature, photoperiod, and population density.

    Science.gov (United States)

    Aufderheide, John; Warbritton, Ryan; Pounds, Nadine; File-Emperador, Sharon; Staples, Charles; Caspers, Norbert; Forbes, Valery

    2006-04-01

    These experiments are part of a larger study designed to investigate the influence of husbandry parameters on the life history of the apple snail, Marisa cornuarietis. The overall objective of the program is to identify suitable husbandry conditions for maintaining multi-generation populations of this species in the laboratory for use in ecotoxicological testing. In this article, we focus on the effects of photoperiod, temperature, and population density on adult fecundity and juvenile growth. Increasing photoperiod from 12 to 16 h of light per day had no effect on adult fecundity or egg hatching and relatively minor effects on juvenile growth and development. Rearing snails at temperatures between 22 degrees C and 28 degrees C did not influence the rates of egg production or egg clutch size. However, the rates of growth and development (of eggs and juveniles) increased with increasing temperature in this range, and when temperatures were reduced to 22 degrees C egg-hatching success was impaired. Juvenile growth and development were more sensitive to rearing density than adult fecundity traits. On the basis of the present results, we conclude that rearing individuals of M. cornuarietis at a temperature of 25 degrees C, a photoperiod of 12L:12D, and a density of <0.8 snails L(-1) (with lower densities for juvenile snails) should provide favorable husbandry conditions for maintaining multi-generation populations of this species.

  19. MTA3 regulates CGB5 and Snail genes in trophoblast

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ying [Department of Obstetrics, Gynecology and Reproductive Biology, Michigan State University, Grand Rapids, MI 49503 (United States); Miyazaki, Jun [Department of Obstetrics and Gynecology, Fujita Health University School of Medicine, Fujita Health University, Toyoake (Japan); Division of Molecular Genetics, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake (Japan); Nishizawa, Haruki [Department of Obstetrics and Gynecology, Fujita Health University School of Medicine, Fujita Health University, Toyoake (Japan); Kurahashi, Hiroki [Division of Molecular Genetics, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake (Japan); Leach, Richard, E-mail: Richard.Leach@hc.msu.edu [Department of Obstetrics, Gynecology and Reproductive Biology, Michigan State University, Grand Rapids, MI 49503 (United States); Department of Obstetrics, Gynecology and Women’s Health, Spectrum Health Medical Group, Grand Rapids, MI 49503 (United States); Wang, Kai, E-mail: Kai.Wang@hc.msu.edu [Department of Obstetrics, Gynecology and Reproductive Biology, Michigan State University, Grand Rapids, MI 49503 (United States)

    2013-04-19

    Highlights: •Impaired MTA3, raised CGB5 and Snail expression are associated with preeclampsia. •Knock-down of MTA3 causes up-regulation of CGB5 and Snail genes in BeWo cells. •MTA3 occupies CGB5 and Snail gene promoters in BeWo cells. -- Abstract: Secreted by the placental trophoblast, human chorionic gonadotropin (hCG) is an important hormone during pregnancy and is required for the maintenance of pregnancy. Previous studies have shown that dys-regulation of hCG expression is associated with preeclampsia. However, the exact relationship between altered hCG levels and development of preeclampsia is unknown. Metastasis associated protein 3 (MTA3), a chromatin remodeling protein, is abundantly expressed in the placental trophoblasts, but its function is unknown. In breast cancer, MTA3 has been shown to repress the expression of Snail and cell migration. However, whether MTA3 acts similarly in the trophoblast has not been investigated. In the present study, we examined the role of MTA3 in regulating the hCG β-subunit gene (gene name: CGB5) and Snail expression in the trophoblast cell line, BeWo, as well as its relevance to the high hCG expression levels seen in preeclampsia. First, we investigated MTA3 expression in preeclamptic placenta as compared to normal control placenta via gene expression microarray and qRT-PCR and found that MTA3 was significantly down-regulated, whereas both CGB5 and Snail were up-regulated in preeclamptic placenta. Secondly, we knocked down MTA3 gene in trophoblast cell line BeWo and found Snail and hCG were both up-regulated, suggesting that MTA3 represses Snail and hCG gene expression in trophoblasts. Next, we cloned the CGB5 and Snail promoters into the pGL3-basic vector individually and found that silencing of MTA3 by siRNA resulted in an increase of both CGB5 and Snail promoter activities. To confirm that this MTA3 inhibition is a direct effect, we performed a chromatin immune-precipitation (ChIP) assay and found that MTA3

  20. Compatibility and sex in a snail-schistosome system.

    Science.gov (United States)

    Webster, J P

    2001-04-01

    Knowledge of the genetics underlying resistance to parasitic infection has important repercussions for our understanding of infection dynamics and the mechanisms of host-parasite co-evolution. The aim here was to determine for a Biomphalaria glabrato-Schistosoma mansoni system whether (1) resistance is dominant over susceptibility, (2) it is possible to crossbreed snails to be simultaneously resistant and/or susceptible to more than one parasite strain and (3) compatibility genotype affects reproductive strategy. Using replicate snail strains artificially selected for either resistance or susceptibility to single replicate parasite strains, individual snails from each line were paired with a selected partner of matched or non-matched compatibility status and cross-breeding was identified by RAPD-PCR. The resulting compatibility phenotype of all offspring was determined. Support for all 3 hypotheses were obtained. The results are discussed in terms of their applied and theoretical implications.

  1. Geographic distribution of Angiostrongylus cantonensis in wild rats (Rattus rattus) and terrestrial snails in Florida, USA.

    Science.gov (United States)

    Stockdale Walden, Heather D; Slapcinsky, John D; Roff, Shannon; Mendieta Calle, Jorge; Diaz Goodwin, Zakia; Stern, Jere; Corlett, Rachel; Conway, Julia; McIntosh, Antoinette

    2017-01-01

    The parasitic nematode Angiostrongylus cantonensis is a major cause of eosinophilic meningitis in humans, and has been documented in other incidental hosts such as birds, horses, dogs and non-human primates. It is endemic in Hawaii, and there have been sporadic reports in the southern continental United States. This parasite uses rats as definitive hosts and snails as intermediate hosts. In this study, we collected potential definitive and intermediate hosts throughout Florida to ascertain the geographic distribution in the state: Rats, environmental rat fecal samples, and snails were collected from 18 counties throughout the state. Classical diagnostics and morphological identification, along with molecular techniques were used to identify nematode species and confirm the presence of A. cantonensis. Of the 171 Rattus rattus collected, 39 (22.8%) were positive for A. cantonensis, and 6 of the 37 (16.2%) environmental rat fecal samples collected in three of the surveyed counties were also positive for this parasite by real time PCR. We examined 1,437 gastropods, which represented 32 species; 27 (1.9%) were positive for A. cantonensis from multiple sites across Florida. Three non-native gastropod species, Bradybaena similaris, Zachrysia provisoria, and Paropeas achatinaceum, and three native gastropod species, Succinea floridana, Ventridens demissus, and Zonitoides arboreus, which are newly recorded intermediate hosts for the parasite, were positive for A. cantonensis. This study indicates that A. cantonensis is established in Florida through the finding of adult and larval stages in definitive and intermediate hosts, respectively, throughout the state. The ability for this historically subtropical nematode to thrive in a more temperate climate is alarming, however as the climate changes and average temperatures rise, gastropod distributions will probably expand, leading to the spread of this parasite in more temperate areas. Through greater awareness of host species

  2. Effects of trematode parasitism on the shell morphology of snails from flow and nonflow environments.

    Science.gov (United States)

    Gustafson, Kyle D; Bolek, Matthew G

    2016-03-01

    The primary function of the gastropod shell is protection. However, shells that function well in one environment may be maladaptive in another. Upon infection, the snail shell protects internal parasites and it is to the parasite's advantage to optimize, or not interfere with, shell functionality. However, parasites, particularly trematodes, are often pathogenic and it is not clear if parasitism will induce environment-dependent or -independent changes to gastropod shells. We conducted a field study and a complementary laboratory experiment to examine the effects of trematode parasitism on shell characteristics (shape, size, and crush resistance) of Physa acuta snails in flow and nonflow environments using geometric morphometrics and crush assays. Field results indicate wetland (nonflow) snails had large, crush resistant shells with narrow apertures and tall spires. In contrast, stream (flow) snails had small, weak shells with wide apertures and short spires. Parasitism had no apparent effect on the crush resistance of wetland snails but significantly reduced the crush resistance of stream snails. Parasitism had no significant effect on overall shell shape in stream or wetland snails. Similar to the results of our field study, nonflow tank snails had significantly more crush resistant shells than flow tank snails. Additionally, the shapes of flow and nonflow tank snails significantly differed where nonflow tank snails resembled wetland snails and flow tank snails resembled stream snails. For laboratory snails, parasitism reduced crush resistance regardless of flow/nonflow treatment. Our results demonstrate that habitat and/or flow treatment was the primary factor affecting P. acuta shell morphology and that trematode parasitism played a secondary role.

  3. Negative Regulatory Role of TWIST1 on SNAIL Gene Expression.

    Science.gov (United States)

    Forghanifard, Mohammad Mahdi; Ardalan Khales, Sima; Farshchian, Moein; Rad, Abolfazl; Homayouni-Tabrizi, Masoud; Abbaszadegan, Mohammad Reza

    2017-01-01

    Epithelial-mesenchymal transition (EMT) is crucial for specific morphogenetic movements during embryonic development as well as pathological processes of tumor cell invasion and metastasis. TWIST and SNAIL play vital roles in both developmental and pathological EMT. Our aim in this study was to investigate the functional correlation between TWIST1 and SNAIL in human ESCC cell line (KYSE-30). The packaging cell line GP293T was cotransfected with either control retroviral pruf-IRES-GFP plasmid or pruf-IRES-GFP-hTWIST1 and pGP plasmid. The KYSE-30 ESCC cells were transduced with produced viral particles and examined with inverted fluorescence microscope. DNA was extracted from transduced KYSE-30 cells and analyzed for copy number of integrated retroviral sequences in the target cell genome. The concentration of retroviral particles was determined by Real-time PCR. After RNA extraction and cDNA synthesis, the mRNA expression of TWIST1 and SNAIL was assessed by comparative real-time PCR amplification. Ectopic expression of TWIST1 in KYSE-30, dramatically reduces SNAIL expression. Retroviral transduction enforced TWIST1 overexpression in GFP-hTWIST1 nearly 9 folds in comparison with GFP control cells, and interestingly, this TWIST1 enforced expression caused a - 7 fold decrease of SNAIL mRNA expression in GFP-hTWIST1 compared to GFP control cells. Inverse correlation of TWIST1 and SNAIL mRNA levels may introduce novel molecular gene expression pathway controlling EMT process during ESCC aggressiveness and tumorigenesis. Consequently, these data extend the spectrum of biological activities of TWIST1 and propose that therapeutic repression of TWIST1 may be an effective strategy to inhibit cancer cell invasion and metastasis.

  4. Some quality parameters of land snail meat - Helix pomatia

    Directory of Open Access Journals (Sweden)

    Tojagić Slobodan N.

    2004-01-01

    Full Text Available Considering the tradition in our regions to collect land snails (Helix pomatia for export, which is "disrupted" by social control resulting in limited possibilities to develop this attractive activity, there is a great interest lately for land snail breeding and fattening at farms. For this reason it is necessary to investigate systematically the possibilities to develop this activity in a longer period and in larger areas. The first investigations, although covering only nutritive and health safety aspects of the edible parts yielded the results presented in this work. Chemical composition, the content of some elements and organochlorine insecticides were followed as unavoidable in human living and environment.

  5. One-trial reward learning in the snail Lymnea stagnalis.

    Science.gov (United States)

    Alexander, J; Audesirk, T E; Audesirk, G J

    1984-01-01

    We present evidence that the pond snail Lymnaea stagnalis is capable of aquisition and extensive retention of an appetitively reinforced feeding response after only a single training trial. Food-deprived snails presented with a single pairing of a phagostimulant (a mixture of sucrose and casein digest) and a novel, non-food chemostimulus (amyl acetate) subsequently made feeding responses to the amyl acetate and retained the association for at least 19 days. This demonstration of one-trial, non-aversive classical conditioning enhances the utility of Lymnaea stagnalis as a model system for the detailed analysis of neural mechanisms underlying plasticity.

  6. Snail-induced epithelial-to-mesenchymal transition of MCF-7 breast cancer cells: systems analysis of molecular changes and their effect on radiation and drug sensitivity.

    Science.gov (United States)

    Mezencev, Roman; Matyunina, Lilya V; Jabbari, Neda; McDonald, John F

    2016-03-18

    Epithelial-to-mesenchymal transition (EMT) has been associated with the acquisition of metastatic potential and the resistance of cancer cells to therapeutic treatments. MCF-7 breast cancer cells engineered to constitutively express the zinc-finger transcriptional repressor gene Snail (MCF-7-Snail cells) have been previously shown to display morphological and molecular changes characteristic of EMT. We report here the results of a comprehensive systems level molecular analysis of changes in global patterns of gene expression and levels of glutathione and reactive oxygen species (ROS) in MCF-7-Snail cells and the consequence of these changes on the sensitivity of cells to radiation treatment and therapeutic drugs. Snail-induced changes in global patterns of gene expression were identified by microarray profiling using the Affymetrix platform (U133 Plus 2.0). The resulting data were processed and analyzed by a variety of system level analytical methods. Levels of ROS and glutathione (GSH) were determined by fluorescent and luminescence assays, and nuclear levels of NF-κB protein were determined by an ELISA based method. The sensitivity of cells to ionizing radiation and anticancer drugs was determined using a resazurin-based cell cytotoxicity assay. Constitutive ectopic expression of Snail in epithelial-like, luminal A-type MCF-7 cells induced significant changes in the expression of >7600 genes including gene and miRNA regulators of EMT. Mesenchymal-like MCF-7-Snail cells acquired molecular profiles characteristic of triple-negative, claudin-low breast cancer cells, and displayed increased sensitivity to radiation treatment, and increased, decreased or no change in sensitivity to a variety of anticancer drugs. Elevated ROS levels in MCF-7-Snail cells were unexpectedly not positively correlated with NF-κB activity. Ectopic expression of Snail in MCF-7 cells resulted in morphological and molecular changes previously associated with EMT. The results underscore the

  7. Intraguild predation by shore crabs affects mortality, behavior, growth, and densities of California horn snails

    Science.gov (United States)

    Lorda, J.; Hechinger, R.F.; Cooper, S. D.; Kuris, A. M.; Lafferty, Kevin D.

    2016-01-01

    The California horn snail, Cerithideopsis californica, and the shore crabs, Pachygrapsus crassipesand Hemigrapsus oregonensis, compete for epibenthic microalgae, but the crabs also eat snails. Such intraguild predation is common in nature, despite models predicting instability. Using a series of manipulations and field surveys, we examined intraguild predation from several angles, including the effects of stage-dependent predation along with direct consumptive and nonconsumptive predator effects on intraguild prey. In the laboratory, we found that crabs fed on macroalgae, snail eggs, and snails, and the size of consumed snails increased with predator crab size. In field experiments, snails grew less in the presence of crabs partially because snails behaved differently and were buried in the sediment (nonconsumptive effects). Consistent with these results, crab and snail abundances were negatively correlated in three field surveys conducted at three different spatial scales in estuaries of California, Baja California, and Baja California Sur: (1) among 61 sites spanning multiple habitat types in three estuaries, (2) among the habitats of 13 estuaries, and (3) among 34 tidal creek sites in one estuary. These results indicate that shore crabs are intraguild predators on California horn snails that affect snail populations via predation and by influencing snail behavior and performance.

  8. Microbiological quality of raw and processed wild and cultured edible snails.

    Science.gov (United States)

    Parlapani, Foteini F; Neofitou, Christos; Boziaris, Ioannis S

    2014-03-15

    An increasing interest in snail farming in Greece and other European countries has been observed. Despite the fact that edible snails have been involved with problems of Salmonella spp. contamination, there are to our knowledge only limited studies regarding microbiological safety and hygiene of such products. Enumeration of microbial populations and presence/absence of Salmonella spp. in snail meat and intestines of wild Cornu aspersum, Helix lucorum and cultured Cornu aspersum snails from indoor/outdoor type farms was conducted. Furthermore, snail-processing steps were simulated in the laboratory and the population reduction in snail meat was determined. Microbial populations were higher in intestines than snail meat in almost all cases. Escherichia coli/coliforms and Enterococcus spp. populations were lower in the intestines and snail meat of cultured C. aspersum. Salmonella spp. were detected in the intestines and snail meat of wild snails only. The high levels of bacterial populations were considerably reduced after the appropriate processing. The lower populations of E. coli/coliforms, Enterococcus spp. and especially the absence of Salmonella spp. in cultured snails show that the controlled conditions decrease the possibility of pathogen presence and contribute to food safety and public health. © 2013 Society of Chemical Industry.

  9. Expression and activity of SNAIL transcription factor during Epithelial to Mesenchymal Transition (EMT) in cancer progression.

    Science.gov (United States)

    Papiewska-Pająk, Izabela; Kowalska, Maria A; Boncela, Joanna

    2016-09-19

    Inhibition of E-cadherin gene expression by transcription factor SNAIL is known to be a crucial element of Epithelial to Mesenchymal Transition; EMT. Epigenetic regulation of E-cadherin expression is regulated by SNAIL binding to E-box sequences in the CDH1 gene promoter and recruiting enzymes belonging to repressor complexes that are directly engaged in histone modifications and DNA methylation leading to the modification of chromatin structure. SNAIL involvement in cell acquisition of invasive phenotype is based on direct suppression of tight-junction and gap junction proteins. The nuclear localization of SNAIL is required for SNAIL activity and protects this factor from proteasomal degradation in the cytoplasm. The main factor engaged in that process is GSK- 3β kinase. Expression and stability of SNAIL is regulated on the transctriptional and posttranscriptional levels by a number of signaling molecules and biological factors, for example: TGF-β, TNF-α, ILK and NFκB. The expression of SNAIL in cancer cells is also regulated by micro-RNA, mainly by miR-34. Increased expression of SNAIL, observed in many human cancers, has been correlated with increased resistance to chemio-, radio - or immunotherapy, gain of cancer stem cells features and migrative and invasive characteristics, which leads to tumor metastases. Understanding of the SNAIL's mechanism of action may lead to new treatment strategies in cancer directed to interfere with signaling pathways that either activate SNAIL or are activated by SNAIL.

  10. DNA strand breaks detected in embryos of the adult snails, Potamopyrgus antipodarum, and in neonates exposed to genotoxic chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Vincent-Hubert, Francoise, E-mail: francoise.vincent-hubert@irstea.fr [Unite de Recherche Hydrosystemes et Bioprocedes, equipe BELCA, IRSTEA/CEMAGREF, 1 rue Pierre-Gilles de Gennes, CS10030, 92761 Antony cedex, 92163 Antony (France); Revel, Messika [Unite de Recherche Hydrosystemes et Bioprocedes, equipe BELCA, IRSTEA/CEMAGREF, 1 rue Pierre-Gilles de Gennes, CS10030, 92761 Antony cedex, 92163 Antony (France); Garric, Jeanne [MALY Laboratoire d' ecotoxicologie, IRSTEA/CEMAGREF, 23 bis Quai Chauveau, 69006 Lyon (France)

    2012-10-15

    We tested the freshwater mudsnail Potamopyrgus antipodarum, which is a species that has already been used for endocrine-disrupting compounds (EDCs) to determine whether early life stages of aquatic organisms are sensitive to genotoxic chemicals. For this purpose, we first developed the alkaline comet assay on adults, embryos, and neonates. The comet assay protocol was validated on both embryonic cells exposed in vitro to hydrogen peroxide and adult snails in the reproducing stage exposed to methyl methane sulfonate. During the latter experiment, DNA strand breaks were investigated on both embryonic cells and on adult gill cells. The second part of this study investigated the stability of DNA strand breaks in adult reproducing snails and neonates exposed to cadmium (Cd) and bisphenol A for 8 days. Hydrogen peroxide-induced DNA strand breaks in vitro in isolated embryonic cells. Exposure of adult reproducing snails to methyl methane sulfonate for 24 h induced DNA strand breaks in embryos. Bisphenol A induced a significant increase in the DNA strand-break level in whole embryonic cells and whole neonate cells. Cd was genotoxic for both embryos and neonates during the exposure time and also after 7 days of depuration, suggesting that Cd could inhibit DNA repair enzymes. These preliminary results on this original model have encouraged us to consider the impact of genotoxic environmental contaminants on the F1 generation.

  11. Histamine Immunoreactive Elements in the Central and Peripheral Nervous Systems of the Snail, Biomphalaria spp., Intermediate Host for Schistosoma mansoni.

    Science.gov (United States)

    Habib, Mohamed R; Mohamed, Azza H; Osman, Gamalat Y; Sharaf El-Din, Ahmed T; Mossalem, Hanan S; Delgado, Nadia; Torres, Grace; Rolón-Martínez, Solymar; Miller, Mark W; Croll, Roger P

    2015-01-01

    Histamine appears to be an important transmitter throughout the Animal Kingdom. Gastropods, in particular, have been used in numerous studies establishing potential roles for this biogenic amine in the nervous system and showing its involvement in the generation of diverse behaviours. And yet, the distribution of histamine has only previously been described in a small number of molluscan species. The present study examined the localization of histamine-like immunoreactivity in the central and peripheral nervous systems of pulmonate snails of the genus Biomphalaria. This investigation demonstrates immunoreactive cells throughout the buccal, cerebral, pedal, left parietal and visceral ganglia, indicative of diverse regulatory functions in Biomphalaria. Immunoreactivity was also present in statocyst hair cells, supporting a role for histamine in graviception. In the periphery, dense innervation by immunoreactive fibers was observed in the anterior foot, perioral zone, and other regions of the body wall. This study thus shows that histamine is an abundant transmitter in these snails and its distribution suggest involvement in numerous neural circuits. In addition to providing novel subjects for comparative studies of histaminegic neurons in gastropods, Biomphalaria is also the major intermediate host for the digenetic trematode parasite, which causes human schistosomiasis. The study therefore provides a foundation for understanding potential roles for histamine in interactions between the snail hosts and their trematode parasites.

  12. A preliminary knowledge-driven prediction model of snail distribution in the Poyang Lake region

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Present monitoring and prediction of schistosomiasis's intermediate parasite,snail,are based on remote sensing image's spectral signatures,and the calculation result iS in fact an incomplete-constraints solution.TM image of the Poyang Lake region on October 31,2005 was combined with GIS thematic data(DEM,boundary of the Poyang Lake,vegetation,soil and land use)to make a prediction on snail spatial distribution in the region by remote sensing,geo-informatics and knowledge-driven modeling according to mechanism of snail occurrence.Result shows that with change of overall fuzzy membership of snail occurrence from high to low,snail occurrence of the snail samples of validation group goes up to 81% within 10% high fuzzy membership range,denoting high efficiency of the model in predicting snail occurrence.

  13. Insights into the Evolutionary History of an Extinct South American Freshwater Snail Based on Historical DNA

    Science.gov (United States)

    Strong, Ellen E.; Rumi, Alejandra; Peso, Juana G.

    2016-01-01

    Highly oxygenated freshwater habitats in the High Paraná River (Argentina–Paraguay) were home to highly endemic snails of the genus Aylacostoma, which face extinction owing to the impoundment of the Yacyretá Reservoir in the 1990s. Two species, A. chloroticum and A. brunneum, are currently included in an ongoing ex situ conservation programme, whereas A. guaraniticum and A. stigmaticum are presumed extinct. Consequently, the validity and affinities of the latter two have remained enigmatic. Here, we provide the first molecular data on the extinct A. stigmaticum by means of historical DNA analysis. We describe patterns of molecular evolution based on partial sequences of the mitochondrial 12S ribosomal RNA gene from the extinct species and from those being bred within the ex situ programme. We further use this gene to derive a secondary structure model, to examine the specific status of A. stigmaticum and to explore the evolutionary history of these snails. The secondary structure model based on A. stigmaticum revealed that most polymorphic sites are located in unpaired regions. Our results support the view that the mitochondrial 12S region is an efficient marker for the discrimination of species, and the extinct A. stigmaticum is recognized here as a distinct evolutionary genetic species. Molecular phylogenetic analyses revealed a sister group relationship between A. chloroticum and A. brunneum, and estimated divergence times suggest that diversification of Aylacostoma in the High Paraná River might have started in the late Miocene via intra-basin speciation due to a past marine transgression. Finally, our findings reveal that DNA may be obtained from dried specimens at least 80 years after their collection, and confirms the feasibility of extracting historical DNA from museum collections for elucidating evolutionary patterns and processes in gastropods. PMID:28033407

  14. H+ channels in embryonic Biomphalaria glabrata cell membranes: Putative roles in snail host-schistosome interactions

    Science.gov (United States)

    Wright, Brandon J.; Bickham-Wright, Utibe; Yoshino, Timothy P.; Jackson, Meyer B.

    2017-01-01

    The human blood fluke Schistosoma mansoni causes intestinal schistosomiasis, a widespread neglected tropical disease. Infection of freshwater snails Biomphalaria spp. is an essential step in the transmission of S. mansoni to humans, although the physiological interactions between the parasite and its obligate snail host that determine success or failure are still poorly understood. In the present study, the B. glabrata embryonic (Bge) cell line, a widely used in vitro model for hemocyte-like activity, was used to investigate membrane properties, and assess the impact of larval transformation proteins (LTP) on identified ion channels. Whole-cell patch clamp recordings from Bge cells demonstrated that a Zn2+-sensitive H+ channel serves as the dominant plasma membrane conductance. Moreover, treatment of Bge cells with Zn2+ significantly inhibited an otherwise robust production of reactive oxygen species (ROS), thus implicating H+ channels in the regulation of this immune function. A heat-sensitive component of LTP appears to target H+ channels, enhancing Bge cell H+ current over 2-fold. Both Bge cells and B. glabrata hemocytes express mRNA encoding a hydrogen voltage-gated channel 1 (HVCN1)-like protein, although its function in hemocytes remains to be determined. This study is the first to identify and characterize an H+ channel in non-neuronal cells of freshwater molluscs. Importantly, the involvement of these channels in ROS production and their modulation by LTP suggest that these channels may function in immune defense responses against larval S. mansoni. PMID:28319196

  15. Fascioliasis of livestock and snail host for Fasciola in the Altiplano Region of Bolivia.

    Science.gov (United States)

    Ueno, H; Arandia, R; Morales, G; Medina, G

    1975-01-01

    Fascioliasis caused by Fasciola hepatica was a serious problem for sheep and alpacas in the Altiplano Region of Bolivia. In some provinces close to Lake Titicaca, the raising of sheep was forced to discontinue, because infection with the fluke made it unprofitable and almost impossible. It was proved that in the Altiplano Region, two species of freshwater snails, Lymnaea viatrix and L. cubensis var., served as intermediate hosts for F. hepatica. In some subtropical areas of Bolivia, these snails could not be found, although other Lymnaea sp. was widely distributed there. As it is possible for Lymnaea sp. to be intermediate host for the fluke, further studies are required on the identification. Acute fascioliasis of sheep occurred in the Altiplano Region principally during a period from May to July, or the dry season. In some areas, the mortality rate of infected sheep was roughly estimated as 15 to 25% annually. Contamination with Fasciola metacercariae of herbage and semi-aquatic plants grown in a swamp in one of these areas was biologically assessed, using guinea pigs. Plants of Compositae and Eleocharis sp. were contaminated most intensely and those of Senicio sp. and Vallisneria sp. carried a fairly large number of cysts, while plants of Scirpus sp. and Ranunclaceae carried only a few cysts. No signs of Fasciola infection were observed in any animal given the plants of Liliaceae.

  16. Genetic structure of faucet snail, Bithynia tentaculata populations in North Americal based on microsattelite markers

    Science.gov (United States)

    Perez, Kathryn E.; Werren, Rebecca L.; Lynum, Christopher A.; Hartman, Levi A.; Majoros, Gabor; Cole, Rebecca A.

    2016-01-01

    Bithynia tentaculata is believed to have been extirpated from North America during the last glacial maximum. It was reintroduced into North America via the Great Lakes basin in the 1800’s and has recently been expanding its geographic range. This snail serves as intermediate host for three trematodes that cause extensive recurring morbidity and mortality events in migratory water birds along the Mississippi River. Using twelve microsatellite loci for ~200 individual snails from 11 populations in North America and Europe, we examined one of the three major geographic regions from which founding populations into the Great Lakes typically originate. Our data supports a single recolonization of North America into the Great Lakes Basin followed by subsequent introduction events from the Great Lakes to other large watersheds in North America. However, additional watersheds in Europe require sampling to confirm this result. No populations with genetic signatures indicative of North American glacial relics were found. The initial invasion of North America was likely not from the Ponto-Caspian basin, the usual source of freshwater invasive species to the Laurentian Great Lakes.

  17. Accumulation of aqueous and dietary thallium by the marine snail, Littorina littorea

    Science.gov (United States)

    Turner, Andrew; Pilsbury, Amy

    2013-09-01

    Thallium is a highly toxic metal whose biogeochemical behaviour in the marine environment is poorly understood. The dominant species predicted in sea water (Tl+) is also chemically and biologically analogous to the potassium ion. In this study, the accumulation of Tl(I) by the littorinid snail, Littorina littorea, was examined under carefully controlled laboratory conditions for a period of five days. The snail was exposed to sea water amended with a sub-phytotoxic concentration of Tl (5 μg L-1) and to a food source (the green macroalga, Ulva lactuca) that had been pre-contaminated by Tl in sea water at the same concentration. L. littorina accumulated Tl from sea water relative to food in a ratio of about 20:1 and there were no significant differences in Tl concentrations among the different tissues analysed (head, foot, visceral mass, gonads) for each treatment. When availabilities of Tl in each vector were compared, however, it was found that only 2% of sea water Tl was accumulated compared with about 15% of dietary Tl. Uptake of Tl appears to proceed via both the gills and gut, while at the cellular level accumulation likely involves binding with biomolecules and exchange with K+ in potassium-bearing mineralised granules.

  18. Using larval trematodes that parasitize snails to evaluate a saltmarsh restoration project

    Science.gov (United States)

    Huspeni, Todd C.; Lafferty, Kevin D.

    2004-01-01

    We conducted a Before-After-Control-Impact (BACI) study using larval digeneans infecting the California horn snail, Cerithidea californica, to evaluate the success of an ecological restoration project at Carpinteria Salt Marsh in California, USA. Digenean trematodes are parasites with complex life cycles requiring birds and other vertebrates as final hosts. We tested two hypotheses for prevalence and species richness of larval trematodes in C. californica: (1) prior to the restoration, sites to be restored would have lower trematode prevalence and species richness relative to unimpacted control sites, and (2) that these differences would diminish after restoration. The sites to be restored were initially degraded for trematode species. They had a mean trematode prevalence (12%) and species richness (4.5 species) that were lower than control sites (28% trematode prevalence and 7 species). Despite the differences in prevalence, the proportional representation of each trematode species in the total community was similar between sites to be restored and control sites. Over the six years following restoration, trematode prevalence nearly quadrupled at restored sites (43%) while the prevalence at control sites (26%) remained unchanged. In addition, species richness at restored sites doubled (9 species), while species richness at the control sites (7.8 species) did not change. Immediately after restoration, the relative abundance of trematode species using fishes as second intermediate hosts declined while those using molluscs as second intermediate hosts increased. Trematode communities at restored and control sites gradually returned to being similar. We interpret the increase in trematode prevalence and species richness at restored sites to be a direct consequence of changes in bird use of the restored habitat. This study demonstrates a new comparative technique for assessing wetlands, and while it does not supplant biotic surveys, it informs such taxonomic lists. Most

  19. Effects of copper on the egg development and hatching of a freshwater pulmonate snail Lymnaea luteola L.

    Science.gov (United States)

    Khangarot, B S; Das, Sangita

    2010-07-15

    A freshwater invertebrate egg development and hatching toxicity test with an Indian freshwater pulmonate snail, Lymnaea luteola, comprising the following developmental endpoints was described: mortality, development, formation of eyes and foot structure, heart rate, duration of different larval stages, and hatching time. Developmental stages were morula, and at third, fifth, and eighth days; the trochophore, veliger, and hippo larvae, respectively. At the age of about 9th to 11th days after egg laying; more than 95% young snail hatched in control laboratory conditions. To evaluate effects on embryonic development, the pulmonate snail eggs of 24-h old were exposed to a series of nominal copper concentrations. The percentage survival of embryos treated in 10-32 microg l(-1) of Cu after 240 h of exposure drops sharply at veliger and hippo stages. All embryos died at 100-320 microg l(-1) of Cu within 168 h of exposure at trochophore and early veliger stages. The detected abnormalities were malformation of foot, eyes, thinness and incomplete formation of shell, growth retardation, and slow rotation of embryo within the egg capsule as compared to control embryos. Lethal and sublethal effects in terms of mortality and significant delay in hatching could be found in the 3.2, 5.6 and 10 microg l(-1) of Cu concentrations. This species is widely distributed in the Indian subcontinent freshwater reservoirs and more sensitive to Cu than other tested aquatic test organisms; therefore, could be used as a test model of Cu and possibly other pollutants for rapid risk assessment of environmental pollutants. The snail egg embryo bioassay is simple, rapid, highly sensitive, cost-effective, and easy to test under standardized laboratory conditions.

  20. INTRODUCED LAND SNAILS AND SLUGS IN COLOMBIA.

    Science.gov (United States)

    Hausdorf, BERNHARD

    2002-05-01

    Twelve species of introduced land molluscs, including seven slug species, have been found in the cold zone above 2000 m altitude in the Departamentos Cundinamarca and Boyacá, and the Distrito Especial in Colombia. The introduced land molluscs remain generally restricted to disturbed environments, from which native species are often absent. Most recorded species originated from Europe. Deroceras laeve has been present in Colombia for more than a century, whereas the other species are probably more recent introductions. The records of Boettgerilla pallens, which is indigenous to the Caucasus and has spread over Europe only during the last decades, demonstrates that the process of introduction of alien molluscs is continuing.

  1. Prevalence of Cercariae Infection in Lymnaea auricularia (Linnaeus, 1758 in NorthWest of Iran

    Directory of Open Access Journals (Sweden)

    Abbas Imani-Baran

    2011-06-01

    Full Text Available The pond snail Lymnaea auricularia serves as an intermediate host for many digenian species. In West Azerbaijan province, northwestern Iran, the cercariae infection investigation was undertaken in L. auricularia from May to November 2010. Of 6759 collected Lymnaeid snails, 370(5.5% L. auricularia snails were identified. Cercariae infection was found in a number of 276 (74.56 % snails. The results showed that removed cercariae from L. auricularia belonged to Echinostomcercariae (96.38 % and Furcocercariae (3.62 % which were found in two out of 28 sites during the course of study. In summer and fall, the highest prevalence of cercariae infection was recorded for both identified cercariae. It is concluded that L. auricularia could be an important intermediate host of large group digenian trematodes in the region, which is necessary to take consideration in the control program of trematode infection.

  2. Presumable incipient hybrid speciation of door snails in previously glaciated areas in the Caucasus.

    Science.gov (United States)

    Koch, Eva L; Neiber, Marco T; Walther, Frank; Hausdorf, Bernhard

    2016-04-01

    Homoploid hybrid speciation, speciation by hybridization without a change in chromosome number, may be the result of an encounter of closely related species in a habitat that is different from that usually occupied by these species. In the northwestern Caucasus the land snail species Micropontica caucasica and M. circassica form two distinct entities with little admixture at low and intermediate altitudes. However, at higher altitudes in the Lagonaki plateau, which were repeatedly glaciated, Micropontica populations with intermediate characters occur. Admixture analyses based on AFLP data demonstrated that the populations from the Lagonaki plateau are homoploid hybrids that now form a cluster separate from the parental species. The Lagonaki populations are characterized by a mtDNA haplotype clade that has been found in the parental species only once. The fixation of this haplotype clade in most hybrid populations suggests that these haplotypes are better adapted to the cooler conditions in high altitude habitats and have replaced the haplotypes of the parental species in a selective sweep. The fixation of a presumably adaptive mitochondrial haplotype clade in the Lagonaki populations is an important step towards speciation under the differential fitness species concept.

  3. Thermal tolerance and preference of exploited turbinid snails near their range limit in a global warming hotspot.

    Science.gov (United States)

    Lah, Roslizawati Ab; Benkendorff, Kirsten; Bucher, Daniel

    2017-02-01

    Predicted global climate change has prompted numerous studies of thermal tolerances of marine species. The upper thermal tolerance is unknown for most marine species, but will determine their vulnerability to ocean warming. Gastropods in the family Turbinidae are widely harvested for human consumption. To investigate the responses of turbinid snails to future conditions we determined critical thermal maxima (CTMax) and preferred temperatures of Turbo militaris and Lunella undulata from the tropical-temperate overlap region of northern New South Wales, on the Australian east coast. CTMax were determined at two warming rates: 1°C/30min and 1°C/12h. The number of snails that lost attachment to the tank wall was recorded at each temperature increment. At the faster rate, T. militaris had a significantly higher CTMax (34.0°C) than L. undulata (32.2°C). At the slower rate the mean of both species was lower and there was no significant difference between them (29.4°C for T. militaris and 29.6°C for L. undulata). This is consistent with differences in thermal inertia possibly allowing animals to tolerate short periods at higher temperatures than is possible during longer exposure times, but other mechanisms are not discounted. The thermoregulatory behaviour of the turban snails was determined in a horizontal thermal gradient. Both species actively sought out particular temperatures along the gradient, suggesting that behavioural responses may be important in ameliorating short-term temperature changes. The preferred temperatures of both species were higher at night (24.0°C and 26.0°C) than during the day (22.0°C and 23.9°C). As the snails approached their preferred temperature, net hourly displacement decreased. Preferred temperatures were within the average seasonal seawater temperature range in this region. However, with future predicted water temperature trends, the species could experience increased periods of thermal stress, possibly exceeding CTMax and

  4. Arsenic Trioxide Modulates the Central Snail Neuron Action Potential

    Directory of Open Access Journals (Sweden)

    Guan-Ling Lu

    2009-09-01

    Conclusion: As2O3 at 10 mM elicits BoPs in central snail neurons and this effect may relate to the PLC activity of the neuron, rather than protein kinase A activity, or calcium influxes of the neuron. As2O3 at higher concentration irreversibly abolishes the spontaneous action potentials of the neuron.

  5. SNAILs promote G1 phase in selected cancer cells.

    Science.gov (United States)

    Wu, Ya-Lan; Xue, Jian-Xin; Zhou, Lin; Deng, Lei; Shang, Yan-Na; Liu, Fang; Mo, Xian-Ming; Lu, You

    2015-11-01

    Cells can acquire a stem-like cell phenotype through epithelial-mesenchymal transition (EMT). However, it is not known which of the stem-like cancer cells are generated by these phenotype transitions. We studied the EMT-inducing roles of SNAILs (the key inducers for the onset of EMT) in selected cancer cells (lung cancer cell line with relatively stable genome), in order to provide more implications for the investigation of EMT-related phenotype transitions in cancer. However, SNAILs fail to induce completed EMT. In addition, we proved that Snail accelerates the early G1 phase whereas Slug accelerates the late G1 phase. Blocking G1 phase is one of the basic conditions for the onset of EMT-related phenotype transitions (e.g., metastasis, acquiring stemness). The discovery of this unexpected phenomenon (promoting G1 phase) typically reveals the heterogeneity of cancer cells. The onset of EMT-related phenotype transitions in cancer needs not only the induction and activation of SNAILs, but also some particular heredity alterations (genetic or epigenetic alterations, which cause heterogeneity). The new connection between heredity alteration (heterogeneity) and phenotype transition suggests a novel treatment strategy, the heredity alteration-directed specific target therapy. Further investigations need to be conducted to study the relevant heredity alterations.

  6. Snail arboreality: the microdistribution of Sitalajenyn.si (Gastropoda ...

    African Journals Online (AJOL)

    The vertical shifts of each snail from a horizontal plane passing through the ... carried out during daytime in an air-conditioned room at. 18°C, 24°C, 30°C ..... Tail wagging was circular at lower temperatures but described horizontal strokes at ...

  7. Hydrocarbons in the land snail Cepaea nemoralis (L.) (gastropoda, pulmonata)

    NARCIS (Netherlands)

    Horst, D.J. van der; Oudejans, R.C.H.M.

    1972-01-01

    1. 1. The biosynthesis of hydrocarbons in the snail Cepaea nemoralis was studied after injection of the 14C-labelled precursors acetate, valine, isoleucine and palmitic acid. 2. 2. The highest incorporation was achieved with palmitic acid, although with the other precursors the hydrocarbons were al

  8. Annotated type catalogue of land snails collected from Taiwan (Formosa in the Natural History Museum, London

    Directory of Open Access Journals (Sweden)

    Chungchi Hwang

    2014-07-01

    Full Text Available The present catalogue lists the type specimens of land snail species, collected from Taiwan and deposited in the Natural History Museum, London. Thirty-seven nominal species described by Pfeiffer, Adams, Nevill, Moellendorff, Godwin-Austen and Gude were traced. I present here information on type status, collection data obtained from the registers and labels of each collection, and annotations on the current taxonomic affiliation. Lectotypes of 28 nominal (subspecies were newly designated. One holotype was fixed originally and two holotypes newly fixed by monotypy. Syntypes of two species and paralectotypes of three species were also discovered in the Museum. No specimen of the species Pupina adamsi Sowerby, 1878, which was supposed to be deposited in the NHM, was found. Pictures of the name-bearing types are provided for further research on biodiversity of the island.

  9. Snails in the desert: Assessing the mitochondrial and morphological diversity and the influence of aestivation behavior on lineage differentiation in the Australian endemic Granulomelon Iredale, 1933 (Stylommatophora: Camaenidae).

    Science.gov (United States)

    Criscione, Francesco; Köhler, Frank

    2016-01-01

    Progressive aridification since the mid-Miocene has had a significant influence on the evolution of the biota in the arid zone of central Australia. Especially moisture sensitive groups, such as snails, are often restricted to topographically complex areas, which have acted as refugia in an otherwise inhospitable environment. This historical fragmentation is deemed to be a potent agent of allopatric lineage diversification. Camaenid land snails are amongst only a few terrestrial gastropods that have managed to survive in the arid zone probably due to their ability to escape desiccation through aestivation. Here, we present the first study of the mitochondrial lineage differentiation in an endemic land snail genus from the Australian 'Red Centre', Granulomelon Iredale, 1933. Exposing significant incongruence between mtDNA phylogeny and morphology-based taxonomy, we completely revise the species and genus level taxonomy of this camaenid group. We demonstrate that this genus contains three species, G. grandituberculatum, G. adcockianum and G. squamulosum, which have so far been assigned to different genera: Granulomelon Iredale, 1933 (junior synonym: Baccalena Iredale, 1937), Basedowena Iredale, 1937 and Pleuroxia Ancey, 1887. Two of these species are widespread comprising multiple divergent mitochondrial lineages. Based on a molecular clock estimate, these lineages diverged approximately during the mid-Pleistocene, a period of particularly severe aridification. The phylogeographic patterns are consistent with an isolation-by-distance model in one species but not the other. We suggest that these differences can be attributed to their distinctive aestivation behavior.

  10. Lymnaea glabra: progressive increase in susceptibility to Fasciola hepatica through successive generations of experimentally infected snails.

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    Rondelaud, D; Teukeng, F F Djuikwo; Vignoles, P; Dreyfuss, G

    2015-07-01

    Experimental infections of Lymnaea glabra (two populations) with Fasciola hepatica were carried out during seven successive snail generations, to determine if prevalence and intensity of snail infection increased over time through descendants of snails already infected with F. hepatica. Controls were descendants coming from uninfected parents and infected according to the same protocol. No larval forms were found in the bodies of control snails coming from uninfected parents. In contrast, prevalence and intensity of F. hepatica infection in snails originating from infected parents progressively increased from the F2 or F3 to the F6 generation of L. glabra. In another experiment carried out with the F7 generations of L. glabra and a single generation of Galba truncatula (as controls), the prevalence of F. hepatica infection and the total number of cercariae were lower in L. glabra (without significant differences between both populations). If the number of cercariae shed by infected snails was compared to overall cercarial production noted in snails containing cercariae but dying without emission, the percentage was greater in G. truncatula (69% instead of 52-54% in L. glabra). Even if most characteristics of F. hepatica infection were lower in L. glabra, prevalence and intensity of parasite infection increased with snail generation when tested snails came from infected parents. This mode of snail infection with F. hepatica suggests an explanation for cases of fasciolosis occurring in cattle-breeding farms where paramphistomosis is lacking and G. truncatula is absent.

  11. Snail as a key regulator of PRL-3 gene in colorectal cancer.

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    Zheng, Ping; Meng, Hui-Min; Gao, Wei-Zhe; Chen, Lin; Liu, Xun-Hua; Xiao, Zheng-Quan; Liu, Yong-Xia; Sui, Hong-Mei; Zhou, Jun; Liu, Yu-Hong; Li, Jian-Ming

    2011-10-15

    The regulators of a key metastasis gene PRL-3 in colorectal cancer (CRC) are still largely unknown. We found three potential binding sites of Snail, a key transcriptional factor involved in the epithelial-mesenchymal transition (EMT), in the region of PRL-3 promoter (located at -642 to -383). Moreover, our results showed that one of the Snail binding sites (located at -624 to -619) was the key element to maintain promoter activity of human PRL-3 gene. The transcriptional activity of PRL-3 promoter was abolished after the Snail binding site (located at -624 to -619) was mutated. Both promoter activity and protein expression of PRL-3 in CRC cell lines could be regulated by Snail. In clinical samples of CRC and metastatic lymph node of CRC, expression of PRL-3 protein was correlated with expression of Snail protein. Functional studies using gene over-expression and knockdown methods indicated that Snail promoted proliferation, cell adhesion and migration of human CRC cells. In SW480 cells with PRL-3 stable knockdown, cell proliferation increased after Snail was up-regulated. Our data first reveal transcriptional factor Snail as a key regulator of PRL-3 in CRC. The link between Snail and PRL-3 suggests a new potential mechanism of Snail contributing to progression and metastasis of CRC.

  12. Cten promotes epithelial-mesenchymal transition through the post-transcriptional stabilization of Snail.

    Science.gov (United States)

    Thorpe, Hannah; Asiri, Abdulaziz; Akhlaq, Maham; Ilyas, Mohammad

    2017-07-10

    Cten promotes cell migration however the knowledge of underlying signalling pathways is sparse. We have shown that Cten downregulates E-cadherin, a feature of epithelial to mesenchymal transition (EMT). This prompted us to investigate whether Cten further contributed to EMT processes to regulate cell motility. The regulation of Snail by Cten was investigated following overexpression, knockdown (by RNA-interference) or knockout of Cten in HCT116, Caco-2 and SW620 colorectal cancer (CRC) cell lines. Subsequently, the cycloheximide (CHX) pulse chase assay was used to investigate changes in Snail protein stability and the functional relevance of Cten-Snail signalling was investigated. Snail was identified as a downstream target of Cten signalling using multiple approaches of Cten expression manipulation. Furthermore, this activity was mediated through the SH2 domain of Cten. The CHX assay confirmed that Cten was regulating Snail at a post transcriptional level and this was through the prevention of Snail degradation. Cell migration, invasion and colony formation efficiency were increased following forced expression of GFP-Cten but subsequently lost when Snail was knocked down, demonstrating a functional Cten-Snail signalling axis. In conclusion, we have described a novel Cten-Snail signaling pathway that contributes to cell motility in CRC, mediated by the stabilization of Snail protein. This finding potentially furthers the understanding of EMT regulatory networks in cancer metastasis. © 2017 Wiley Periodicals, Inc.

  13. FBXL5 Inhibits Metastasis of Gastric Cancer Through Suppressing Snail1

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    Weidong Wu

    2015-03-01

    Full Text Available Background/Aims: The Snail family of transcription factors controls epithelial to mesenchymal transition (EMT, a process associated with tumorigenesis originated from epithelial cells. Snail1 is a member from Snail family and upregulation of Snail1 has been detected in gastric cancer (GC, suggesting a potential role of Snail1 in GC metastasis. We have recently reported that FBXL5 regulates cortactin by inducing its ubiquitylation and subsequent proteasomal degradation, resulting in inhibition of metastasis of GC. However, a role of FBXL4 in regulation of other EMT-associated proteins is not unknown. Methods: The levels of FBXL5 and Snail1 as well as their relationship were determined in GC specimen. Co-immunoprecipitation (IP was performed to detect the interaction between Snail1 and FBXL5 in GC cells. The effects on Snail1 by FBXL5 were examined by overexpression of depletion of FBXL5 in GC cells. The invasiveness of the FBXL5-modified GC cells was examined in both scratch wound healing assay and transwell matrix penetration assay. Results: FBXL5 also physiologically interacted with Snail1. FBXL5 inhibited Snail1 to suppress GC cell invasiveness. Conclusion: FBXL5 negatively regulates several EMT-enhancing factors. FBXL5 is an attractive novel target for inhibiting invasion and metastasis of GC cells.

  14. Targeted inactivation of Snail family EMT regulatory factors by a Co(III)-Ebox conjugate.

    Science.gov (United States)

    Harney, Allison S; Meade, Thomas J; LaBonne, Carole

    2012-01-01

    Snail family proteins are core EMT (epithelial-mesenchymal transition) regulatory factors that play essential roles in both development and disease processes and have been associated with metastasis in carcinomas. Snail factors are required for the formation of neural crest stem cells in most vertebrate embryos, as well as for the migratory invasive behavior of these cells. Snail factors have recently been linked to the formation of cancer stem cells, and expression of Snail proteins may be associated with tumor recurrence and resistance to chemotherapy and radiotherapy. We report that Co(III)-Ebox is a potent inhibitor of Snail-mediated transcriptional repression in breast cancer cells and in the neural crest of Xenopus. We further show that the activity of Co(III)-Ebox can be modulated by temperature, increasing the utility of this conjugate as a Snail inhibitor in model organisms. We exploit this feature to further delineate the requirements for Snail function during neural crest development, showing that in addition to the roles that Snail factors play in neural crest precursor formation and neural crest EMT/migration, inhibition of Snail function after the onset of neural crest migration leads to a loss of neural crest derived melanocytes. Co(III)-Ebox-mediated inhibition therefore provides a powerful tool for analysing the function of these core EMT factors with unparalleled temporal resolution. Moreover, the potency of Co(III)-Ebox as a Snail inhibitor in breast cancer cells suggests its potential as a therapeutic inhibitor of tumor progression and metastasis.

  15. The Use of Golden Snail (Pomacea sp. as Animal Feed in the Philippines

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    Serra, AB.

    1997-01-01

    Full Text Available The golden snail is introduced to the Philippines in early 80's for culture as food source. This herbivorous snail, a voracious feeder of live and fresh plant materials become a serious rice pest. Its elimination in the ecosystems is impossible. To use them as animal feed is much better alternative for their control and more environmentally friendly than the use of chemicals. Thus, this mini review paper aimed to collate any existing information on the use of golden snail as animal feed. The different meal forms that can be extracted are golden snail meal (30 % calcium and 15 % crude protein, golden snail meat meal (62 % crude protein and 3336 kcal/kg and golden shell meal (35 % calcium. Feeding trials indicate that golden snail meal can be a part of swine and chicken layer diets up to 15 %. Golden snail meat meal can be a part of broiler chicken diet up to 12 %. Feeding fresh and ground golden snail to ducks can replace 50 % of their diet under total confinement system. Whereas, golden snail meat meal (75 % of the diet plus rice bran can be beneficially fed to tilapia. With the information collated, golden snail can be a promising animal feed in the Philippines.

  16. Patterns of land-snail succession in Central Europe over the last 15,000 years: main changes along environmental, spatial and temporal gradients

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    Juřičková, Lucie; Horsák, Michal; Horáčková, Jitka; Abraham, Vojtěch; Ložek, Vojen

    2014-06-01

    Land snail shell assemblages have been used since the pioneering days of palaeoecology to describe Quaternary environmental changes. Despite the many advantages of this proxy, it has recently been rather overlooked. There are more than 300 mollusc successions from localities throughout the Czech and Slovak Republics, making this a globally unique archive. We selected 91 of these successions for radiocarbon dating and further detailed processing. Based on analyses of 828 mollusc assemblages we found a significant increase in both total species richness and number of forest species since the Lateglacial, with a decrease in both after the Middle Holocene. In contrast, the opposite response was found for open-country species and the proportion of xerophilous species. The proportion of forest and open-country species reversed at the Pleistocene/Holocene transition (approx. 11,500 cal yrs BP). Changes in species richness were rather stable across the study area and at different elevation, contrary to changes in species composition. MDS ordination based on presence/absence data show four main patterns of species composition associated with the number of forest species in a sample, position of site along the west-east direction, the proportion of hygrophilous species and, finally, with the age of the mollusc assemblage. The number of forest species indicates the main pattern of changes in the composition of Central European land snail assemblages from the Lateglacial to the present. We confirmed the application and temporal stability of ecological groups of snails as a useful tool for reconstruction of the terrestrial palaeoenvironment.

  17. Overexpression of Snail in retinal pigment epithelial triggered epithelial–mesenchymal transition

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hui; Li, Min; Xu, Ding; Zhao, Chun; Liu, Guodong; Wang, Fang, E-mail: milwang_122@msn.com

    2014-03-28

    Highlights: • First reported overexpression of Snail in RPE cells could directly trigger EMT. • Further confirmed the regulator role of Snail in RPE cells EMT in vitro. • Snail may be a potential therapeutic target to prevent the fibrosis of PVR. - Abstract: Snail transcription factor has been implicated as an important regulator in epithelial–mesenchymal transition (EMT) during tumourigenesis and fibrogenesis. Our previous work showed that Snail transcription factor was activated in transforming growth factor β1 (TGF-β1) induced EMT in retinal pigment epithelial (RPE) cells and may contribute to the development of retinal fibrotic disease such as proliferative vitreoretinopathy (PVR). However, whether Snail alone has a direct role on retinal pigment epithelial–mesenchymal transition has not been investigated. Here, we analyzed the capacity of Snail to drive EMT in human RPE cells. A vector encoding Snail gene or an empty vector were transfected into human RPE cell lines ARPE-19 respectively. Snail overexpression in ARPE-19 cells resulted in EMT, which was characterized by the expected phenotypic transition from a typical epithelial morphology to mesenchymal spindle-shaped. The expression of epithelial markers E-cadherin and Zona occludin-1 (ZO-1) were down-regulated, whereas mesenchymal markers a-smooth muscle actin (a-SMA) and fibronectin were up-regulated in Snail expression vector transfected cells. In addition, ectopic expression of Snail significantly enhanced ARPE-19 cell motility and migration. The present data suggest that overexpression of Snail in ARPE-19 cells could directly trigger EMT. These results may provide novel insight into understanding the regulator role of Snail in the development of retinal pigment epithelial–mesenchymal transition.

  18. Distribution and habitats of Lymnaea natalensis, snail intermediate host of the liver fluke Fasciola gigantica, in South Africa

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    Editorial Office

    2001-09-01

    Full Text Available This paper focuses on the geographical distribution and the habitats of Lymnaea natalensis, the snail intermediate host of the liver fluke, Fasciola gigantica, as reflected by the collection sites of its 4 552 samples currently on record in the National Freshwater Snail Collection (NFSC of South Africa. Although this species was represented in a variety of waterbodies, the majority of samples(±70%came from rivers, brooks and dams and in 70.8% of the cases the water was described as permanent and in 71.8% as slow flowing or standing. The results of life-table studies conducted by various authors indicated that temperature should be a relatively unimportant factor in determining its geographical distribution, but that the availability of permanent water should be decisive for its presence in a given habitat. These results are in agreement with the finding that only 7.5% of the samples of this species in the NFSC were collected in habitats which were described as seasonal. Furthermore, it gives a logical explanation for the sporadic occurrence, or total absence of this species in the more arid regions of South Africa. Water impoundments and irrigation networks contribute to a large extent towards creating perennial habitats which would be suitable for L. natalensis. As intermediate host for one of the liver fluke species which already is an economic factor in South Africa, this certainly is an aspect which ought to be reckoned within the planning and construction of new irrigation schemes.

  19. The Neotropical land snails (Mollusca, Gastropoda) collected by the ‘Comisión Científica del Pacífico’

    Science.gov (United States)

    Araujo, Rafael

    2017-01-01

    The land snails collected by the ‘Comisión Científica del Pacifíco’ (CCP), a Spanish expedition to South and Central America from 1862–1866, are restudied and revised. The historical context of the expedition and the study of its collected material are described. Biographical data is given for the main persons involved. The land snails were previously studied by Joaquin Hidalgo between 1867 and 1893. A total of 3,470 specimens belonging to 211 species are treated in this paper. Of 34 species mentioned by Hidalgo is his catalogue, the corresponding material could not be located. Bulimus visendus Hidalgo, 1869 is now placed in the genus Synapterpes Pilsbry, 1896, a new combination. PMID:28316885

  20. Stirred, not shaken: genetic structure of the intermediate snail host Oncomelania hupensis robertsoni in an historically endemic schistosomiasis area

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    Hauswald Anne-Kathrin

    2011-10-01

    Full Text Available Abstract Background Oncomelania hupensis robertsoni is the sole intermediate host for Schistosoma japonicum in western China. Given the close co-evolutionary relationships between snail host and parasite, there is interest in understanding the distribution of distinct snail phylogroups as well as regional population structures. Therefore, this study focuses on these aspects in a re-emergent schistosomiasis area known to harbour representatives of two phylogroups - the Deyang-Mianyang area in Sichuan Province, China. Based on a combination of mitochondrial and nuclear DNA, the following questions were addressed: 1 the phylogeography of the two O. h. robertsoni phylogroups, 2 regional and local population structure in space and time, and 3 patterns of local dispersal under different isolation-by-distance scenarios. Results The phylogenetic analyses confirmed the existence of two distinct phylogroups within O. h. robertsoni. In the study area, phylogroups appear to be separated by a mountain range. Local specimens belonging to the respective phylogroups form monophyletic clades, indicating a high degree of lineage endemicity. Molecular clock estimations reveal that local lineages are at least 0.69-1.58 million years (My old and phylogeographical analyses demonstrate that local, watershed and regional effects contribute to population structure. For example, Analyses of Molecular Variances (AMOVAs show that medium-scale watersheds are well reflected in population structures and Mantel tests indicate isolation-by-distance effects along waterways. Conclusions The analyses revealed a deep, complex and hierarchical structure in O. h. robertsoni, likely reflecting a long and diverse evolutionary history. The findings have implications for understanding disease transmission. From a co-evolutionary standpoint, the divergence of the two phylogroups raises species level questions in O. h. robertsoni and also argues for future studies relative to the

  1. An annotated catalogue of type specimens of the land snail genus Cyclophorus Monfort, 1810 (Caenogastropoda, Cyclophoridae) in the Natural History Museum, London.

    Science.gov (United States)

    Nantarat, Nattawadee; Sutcharit, Chirasak; Tongkerd, Piyoros; Ablett, Jonathan; Naggs, Fred; Panha, Somsak

    2014-01-01

    The collection of land caenogastropod snails in the genus Cyclophorus Monfort, 1810 housed in the Natural History Museum, London (NHM), includes 52 type lots. Lectotypes have been designated for 43 available species-level names to stabilize existing nomenclature, two previously designated lectotype, two holotypes, one paratype, one syntype, one possible syntype and two paralectotypes are also listed. A complete catalogue of the Cyclophorus types in NHM, London is provided for the first time.

  2. Modelling the spatial and seasonal distribution of suitable habitats of schistosomiasis intermediate host snails using Maxent in Ndumo area, KwaZulu-Natal Province, South Africa.

    Science.gov (United States)

    Manyangadze, Tawanda; Chimbari, Moses John; Gebreslasie, Michael; Ceccato, Pietro; Mukaratirwa, Samson

    2016-11-04

    Schistosomiasis is a snail-borne disease endemic in sub-Saharan Africa transmitted by freshwater snails. The distribution of schistosomiasis coincides with that of the intermediate hosts as determined by climatic and environmental factors. The aim of this paper was to model the spatial and seasonal distribution of suitable habitats for Bulinus globosus and Biomphalaria pfeifferi snail species (intermediate hosts for Schistosoma haematobium and Schistosoma mansoni, respectively) in the Ndumo area of uMkhanyakude district, South Africa. Maximum Entropy (Maxent) modelling technique was used to predict the distribution of suitable habitats for B. globosus and B. pfeifferi using presence-only datasets with ≥ 5 and ≤ 12 sampling points in different seasons. Precipitation, maximum and minimum temperatures, Normalised Difference Vegetation Index (NDVI), Normalised Difference Water Index (NDWI), pH, slope and Enhanced Vegetation Index (EVI) were the background variables in the Maxent models. The models were validated using the area under the curve (AUC) and omission rate. The predicted suitable habitats for intermediate snail hosts varied with seasons. The AUC for models in all seasons ranged from 0.71 to 1 and the prediction rates were between 0.8 and 0.9. Although B. globosus was found at more localities in the Ndumo area, there was also evidence of cohabiting with B. pfiefferi at some of the locations. NDWI had significant contribution to the models in all seasons. The Maxent model is robust in snail habitat suitability modelling even with small dataset of presence-only sampling sites. Application of the methods and design used in this study may be useful in developing a control and management programme for schistosomiasis in the Ndumo area.

  3. Metabolic acceleration in the pond snail Lymnaea stagnalis?

    Science.gov (United States)

    Zimmer, Elke I.; Ducrot, V.; Jager, T.; Koene, J.; Lagadic, L.; Kooijman, S. A. L. M.

    2014-11-01

    Under constant environmental conditions, most animals tend to grow following the von Bertalanffy growth curve. Deviations from this curve can point to changes in the environment that the animals experience, such as food limitation when the available food is not sufficient or suitable. However, such deviations can also point to a phenomenon called metabolic acceleration, which is receiving increasing attention in the field of Dynamic Energy Budget (DEB) modeling. Reasons for such an acceleration are usually changes in shape during ontogeny, which cause changes in the surface area to volume ratio of the organism. Those changes, in turn, lead to changes in some of the model parameters that have length in their dimension. The life-history consequences of metabolic acceleration as implemented in the DEB theory are an s-shaped growth curve (when body size is expressed as a length measure) and a prolongation of the hatching time. The great pond snail Lymnaea stagnalis was earlier found to be food limited during the juvenile phase in laboratory experiments conducted under classical ecotoxicity test protocols. The pond snail has isomorphic shell growth but yet does not exhibit the expected von Bertalanffy growth curve under food limitation. When applying the standard DEB model to data from such life-cycle experiments, we also found that the hatching time is consistently underestimated, which could be a sign of metabolic acceleration. We here present an application of the DEB model including metabolic acceleration to the great pond snail. We account for the simultaneous hermaphroditism of the snail by including a model extension that describes the relative investment into the male and female function. This model allowed us to adequately predict the life history of the snail over the entire life cycle. However, the pond snail does not change in shape substantially after birth, so the original explanation for the metabolic acceleration does not hold. Since the change in shape

  4. [Proceedings of the symposium 'Molluscan Palaeontology' : 11th International Malacological Congress, Siena (Italy) 30th August - 5th September 1992 / A.W. Janssen and R. Janssen (editors)]: Palaeobiogeographical characteristics of the Miocene land snail fauna of Poland

    NARCIS (Netherlands)

    Stworzewicz, E.

    1992-01-01

    A zoogeographical analysis of the Miocene land snail fauna of Poland was carried out on the basis of the author's field investigations, collections, as well as literature data. Until now about a hundred species are known from ten localities. The distribution pattern of the genus Gastrocopta and a hy

  5. Molecular phylogenetics and comparative anatomy of Kimberleytrachia Köhler, 2011 - a genus of land snail endemic to the coastal Kimberley, Western Australia with description of new taxa (Gastropoda, Camaenidae)

    NARCIS (Netherlands)

    Criscione, F.; Köhler, F.

    2014-01-01

    Kimberleytrachia Köhler, 2011 is a genus of camaenid land snail endemic to the Western Australian Kimberley region. It comprises twelve previously recognised species, all of which occur within the high precipitation zone along the north-western coast between the Admiralty Gulf and King Sound and wit

  6. Biomphalaria glabrata transcriptome: cDNA microarray profiling identifies resistant- and susceptible-specific gene expression in haemocytes from snail strains exposed to Schistosoma mansoni

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    Rollinson David

    2008-12-01

    Full Text Available Abstract Background Biomphalaria glabrata is an intermediate snail host for Schistosoma mansoni, one of the important schistosomes infecting man. B. glabrata/S. mansoni provides a useful model system for investigating the intimate interactions between host and parasite. Examining differential gene expression between S. mansoni-exposed schistosome-resistant and susceptible snail lines will identify genes and pathways that may be involved in snail defences. Results We have developed a 2053 element cDNA microarray for B. glabrata containing clones from ORESTES (Open Reading frame ESTs libraries, suppression subtractive hybridization (SSH libraries and clones identified in previous expression studies. Snail haemocyte RNA, extracted from parasite-challenged resistant and susceptible snails, 2 to 24 h post-exposure to S. mansoni, was hybridized to the custom made cDNA microarray and 98 differentially expressed genes or gene clusters were identified, 94 resistant-associated and 4 susceptible-associated. Quantitative PCR analysis verified the cDNA microarray results for representative transcripts. Differentially expressed genes were annotated and clustered using gene ontology (GO terminology and Kyoto Encyclopaedia of Genes and Genomes (KEGG pathway analysis. 61% of the identified differentially expressed genes have no known function including the 4 susceptible strain-specific transcripts. Resistant strain-specific expression of genes implicated in innate immunity of invertebrates was identified, including hydrolytic enzymes such as cathepsin L, a cysteine proteinase involved in lysis of phagocytosed particles; metabolic enzymes such as ornithine decarboxylase, the rate-limiting enzyme in the production of polyamines, important in inflammation and infection processes, as well as scavenging damaging free radicals produced during production of reactive oxygen species; stress response genes such as HSP70; proteins involved in signalling, such as importin 7

  7. Fasciola gigantica transmission in the zoonotic fascioliasis endemic lowlands of Guilan, Iran: experimental assessment.

    Science.gov (United States)

    Ashrafi, Keyhan; Mas-Coma, Santiago

    2014-09-15

    The lowland flatlands around the city of Bandar-Anzali, at the Caspian Sea shore, Guilan province, are an endemic area where Fasciola gigantica appears to be the fasciolid species involved and past outbreaks affecting around 15,000 people and the highest human infection rates in Iran have been reported. Fascioliasis transmission in that area has been experimentally analysed for the first time, by means of assays of monomiracidial (Group A: 120 snails) and pentamiracidial (Group B: 96 snails) infections of local Radix lymnaeid snails with a local cattle F. gigantica isolate. Ribosomal DNA ITS-2 sequencing proved that Lymnaea (Radix) gedrosiana should henceforth be considered a synonym of Radix auricularia, the haplotype found in Bandar-Anzali being identical to that found in many European countries. Survival rates at day 30 postinfection and metacercarial productivity (both higher in Group A) and longevity of the shedding snails (higher in Group B), were affected by the miracidial dose, whereas prepatent period, patent period, infection rate, and the percentages of shedding and infected non-shedding snails did not. The higher percentage of shedding snails in Group A (51.0% versus 37.7%) counteracts the higher number of metacercariae produced in Group B (243.9 ± 259.2 versus 157.2 ± 153.2). High numbers of shedding snails in both experimental groups passed less than 100 cercariae, and 16% in Group A and 35% in Group B produced more than 300 metacercariae, while only four snails (8%) in Group A and two snails (10%) in Group B shed more than 500 metacercariae. Most metacercariae (94.7% in Group A and 85.1% in Group B) were recorded during the first 15 days of patent period. The comparison with results from other fasciolid/lymnaeid systems indicates that the F. gigantica/R. auricularia system of Guilan is highly susceptible and compatible. Results obtained suggest that increased lymnaeid vector populations and not polymiracidial snail infections most probably underlay

  8. Cancer metastasis is accelerated through immunosuppression during Snail-induced EMT of cancer cells.

    Science.gov (United States)

    Kudo-Saito, Chie; Shirako, Hiromi; Takeuchi, Tadashi; Kawakami, Yutaka

    2009-03-03

    Epithelial-mesenchymal transition (EMT) is a key step toward cancer metastasis, and Snail is a major transcription factor governing EMT. Here, we demonstrate that Snail-induced EMT accelerates cancer metastasis through not only enhanced invasion but also induction of immunosuppression. Murine and human melanoma cells with typical EMT features after snail transduction induced regulatory T cells and impaired dendritic cells in vitro and in vivo partly through TSP1 production. Although Snail(+) melanoma did not respond to immunotherapy, intratumoral injection with snail-specific siRNA or anti-TSP1 monoclonal antibody significantly inhibited tumor growth and metastasis following increase of tumor-specific tumor-infiltrating lymphocytes and systemic immune responses. These results suggest that inhibition of Snail-induced EMT could simultaneously suppress both tumor metastasis and immunosuppression in cancer patients.

  9. The evolution of reproductive isolation in a simultaneous hermaphrodite, the freshwater snail Physa

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    Lydeard Charles

    2011-05-01

    Full Text Available Abstract Background The cosmopolitan freshwater snail Physa acuta has recently found widespread use as a model organism for the study of mating systems and reproductive allocation. Mitochondrial DNA phylogenies suggest that Physa carolinae, recently described from the American southeast, is a sister species of P. acuta. The divergence of the acuta/carolinae ancestor from the more widespread P. pomilia appears to be somewhat older, and the split between a hypothetical acuta/carolinae/pomilia ancestor and P. gyrina appears older still. Results Here we report the results of no-choice mating experiments yielding no evidence of hybridization between gyrina and any of four other populations (pomilia, carolinae, Philadelphia acuta, or Charleston acuta, nor between pomilia and carolinae. Crosses between pomilia and both acuta populations yielded sterile F1 progeny with reduced viability, while crosses between carolinae and both acuta populations yielded sterile F1 hybrids of normal viability. A set of mate-choice tests also revealed significant sexual isolation between gyrina and all four of our other Physa populations, between pomilia and carolinae, and between pomilia and Charleston acuta, but not between pomilia and the acuta population from Philadelphia, nor between carolinae and either acuta population. These observations are consistent with the origin of hybrid sterility prior to hybrid inviability, and a hypothesis that speciation between pomilia and acuta may have been reinforced by selection for prezygotic reproductive isolation in sympatry. Conclusions We propose a two-factor model for the evolution of postzygotic reproductive incompatibility in this set of five Physa populations consistent with the Dobzhansky-Muller model of speciation, and a second two-factor model for the evolution of sexual incompatibility. Under these models, species trees may be said to correspond with gene trees in American populations of the freshwater snail, Physa.

  10. Moorean tree snail survival revisited: a multi-island genealogical perspective

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    Meyer Jean-Yves

    2009-08-01

    Full Text Available Abstract Background The mass extirpation of the island of Moorea's endemic partulid tree snail fauna, following the deliberate introduction of the alien predator Euglandina rosea, represents one of the highest profile conservation crises of the past thirty years. All of the island's partulids were thought to be extirpated by 1987, with five species persisting in zoos, but intensive field surveys have recently detected a number of surviving wild populations. We report here a mitochondrial (mt phylogenetic estimate of Moorean partulid wild and captive lineage survival calibrated with a reference museum collection that pre-dates the predator's introduction and that also includes a parallel dataset from the neighboring island of Tahiti. Results Although severe winnowing of Moorea's mt lineage diversity has occurred, seven of eight (six Partula; two Samoana partulid tip clades remain extant. The extinct mt clade occurred predominantly in the P. suturalis species complex and it represented a major component of Moorea's endemic partulid treespace. Extant Moorean mt clades exhibited a complex spectrum of persistence on Moorea, in captivity, and (in the form of five phylogenetically distinct sister lineages on Tahiti. Most notably, three Partula taxa, bearing two multi-island mt lineages, have survived decades of E. rosea predation on Moorea (P. taeniata and in the valleys of Tahiti (P. hyalina and P. clara. Their differential persistence was correlated with intrinsic attributes, such as taxonomy and mt lineages, rather than with their respective within-island distribution patterns. Conclusion Conservation efforts directed toward Moorean and Tahitian partulids have typically operated within a single island frame of reference, but our discovery of robust genealogical ties among survivors on both islands implies that a multi-island perspective is required. Understanding what genetic and/or ecological factors have enabled Partula taeniata, P. hyalina and P

  11. Central role of Snail1 in the regulation of EMT and resistance in cancer: a target for therapeutic intervention

    OpenAIRE

    Kaufhold, Samantha; Bonavida, Benjamin

    2014-01-01

    Snail1 is the founding member of the Snail superfamily of zinc-finger transcription factors, which also includes Snail2 (Slug) and Snail3 (Smuc). The superfamily is involved in cell differentiation and survival, two processes central in cancer research. Encoded by the SNAI1 gene located on human chromosome 20q13.2, Snail1 is composed of 264 amino acids and usually acts as a transcriptional repressor. Phosphorylation and nuclear localization of Snail1, governed by PI3K and Wnt signaling pathwa...

  12. The Biomphalaria glabrata DNA methylation machinery displays spatial tissue expression, is differentially active in distinct snail populations and is modulated by interactions with Schistosoma mansoni.

    Directory of Open Access Journals (Sweden)

    Kathrin K Geyer

    2017-05-01

    Full Text Available The debilitating human disease schistosomiasis is caused by infection with schistosome parasites that maintain a complex lifecycle alternating between definitive (human and intermediate (snail hosts. While much is known about how the definitive host responds to schistosome infection, there is comparably less information available describing the snail's response to infection.Here, using information recently revealed by sequencing of the Biomphalaria glabrata intermediate host genome, we provide evidence that the predicted core snail DNA methylation machinery components are associated with both intra-species reproduction processes and inter-species interactions. Firstly, methyl-CpG binding domain protein (Bgmbd2/3 and DNA methyltransferase 1 (Bgdnmt1 genes are transcriptionally enriched in gonadal compared to somatic tissues with 5-azacytidine (5-AzaC treatment significantly inhibiting oviposition. Secondly, elevated levels of 5-methyl cytosine (5mC, DNA methyltransferase activity and 5mC binding in pigmented hybrid- compared to inbred (NMRI- B. glabrata populations indicate a role for the snail's DNA methylation machinery in maintaining hybrid vigour or heterosis. Thirdly, locus-specific detection of 5mC by bisulfite (BS-PCR revealed 5mC within an exonic region of a housekeeping protein-coding gene (Bg14-3-3, supporting previous in silico predictions and whole genome BS-Seq analysis of this species' genome. Finally, we provide preliminary evidence for parasite-mediated host epigenetic reprogramming in the schistosome/snail system, as demonstrated by the increase in Bgdnmt1 and Bgmbd2/3 transcript abundance following Bge (B. glabrata embryonic cell line exposure to parasite larval transformation products (LTP.The presence of a functional DNA methylation machinery in B. glabrata as well as the modulation of these gene products in response to schistosome products, suggests a vital role for DNA methylation during snail development/oviposition and

  13. Identification of snails within the Bulinus africanus group from East Africa by multiplex SNaPshotäanalysis of single nucleotide polymorphisms within the cytochrome oxidase subunit I

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    Stothard JR

    2002-01-01

    Full Text Available Identification of populations of Bulinus nasutus and B. globosus from East Africa is unreliable using characters of the shell. In this paper, a molecular method of identification is presented for each species based on DNA sequence variation within the mitochondrial cytochrome oxidase subunit I (COI as detected by a novel multiplexed SNaPshotTM assay. In total, snails from 7 localities from coastal Kenya were typed using this assay and variation within shell morphology was compared to reference material from Zanzibar. Four locations were found to contain B. nasutus and 2 locations were found to contain B. globosus. A mixed population containing both B. nasutus and B. globosus was found at Kinango. Morphometric variation between samples was considerable and UPGMA cluster analysis failed to differentiate species. The multiplex SNaPshotTM assay is an important development for more precise methods of identification of B. africanus group snails. The assay could be further broadened for identification of other snail intermediate host species.

  14. Snail2 is an essential mediator of Twist1-induced epithelial-mesenchymal transition and metastasis

    OpenAIRE

    Casas, Esmeralda; Kim, Jihoon; Bendesky, Andrés; Ohno-Machado, Lucila; Wolfe, Cecily J.; Yang, Jing

    2011-01-01

    To metastasize, carcinoma cells must attenuate cell-cell adhesion to disseminate into distant organs. A group of transcription factors, including Twist1, Snail1, Snail2, ZEB1, and ZEB2, have been shown to induce Epithelial-Mesenchymal Transition (EMT), thus promoting tumor dissemination. However, it is unknown whether these transcription factors function independently or coordinately to activate the EMT program. Here we report that direct induction of Snail2 is essential for Twist1 to induce ...

  15. Effects of engineered nanoparticles on survival, reproduction, and behaviour of freshwater snail, Physa acuta (Draparnaud, 1805)

    CSIR Research Space (South Africa)

    Musee, N

    2010-01-01

    Full Text Available of test specimens P. acuta is a common pulmonate snail mostly found in streams, ponds, and lakes throughout South Africa. The P. acuta snails used in this bioassay were obtained from batch cultures of offspring col- lected from the Rietvlei nature..., and themselves are prey to fish, and other invertebrate predators (Osenberg and Mittelbach, 1989; Underwood, 1991; Bernot and Turner, 2001). In addition, the pulmonate snails are important detritivores in standing and running water. Cummins (1974) devised...

  16. Sensitivity of the sea snail Gibbula umbilicalis to mercury exposure--linking endpoints from different biological organization levels.

    Science.gov (United States)

    Cabecinhas, Adriana S; Novais, Sara C; Santos, Sílvia C; Rodrigues, Andreia C M; Pestana, João L T; Soares, Amadeu M V M; Lemos, Marco F L

    2015-01-01

    Mercury contamination is a common phenomenon in the marine environment and for this reason it is important to develop cost-effective and relevant tools to assess its toxic effects on a number of different species. To evaluate the possible effects of Hg in the sea snail Gibbula umbilicalis, animals were exposed to increasing concentrations of the contaminant in the ionic form for 96 h. After this exposure period, mortality, feeding and flipping behavior, the activity of the biomarkers glutathione S-transferase, superoxide dismutase, catalase, lactate dehydrogenase and cholinesterase, the levels of lipid peroxidation and cellular energy allocation were measured. After 96 h of exposure to the highest Hg concentration (≈LC20), there was a significant inhibition of the cholinesterase activity as well as impairment in the flipping behavior and post-exposure feeding of the snails. Cholinesterase inhibition was correlated with the impairment of behavioral responses also caused by exposure to Hg. These endpoints, including the novel flipping test, revealed sensitivity to Hg and might be used as relevant early warning indicators of prospective effects at higher biological organization levels, making these parameters potential tools for environmental risk assessment. The proposed test species showed sensitivity to Hg and proved to be a suitable and resourceful species to be used in ecotoxicological testing to assess effects of other contaminants in marine ecosystems.

  17. Experimental infections with Fasciola in snails, mice and rabbits.

    Science.gov (United States)

    Hussein, Abdel-Nasser A; Khalifa, R M A

    2008-05-01

    Experimental infection trails of Lymnaea (cailliaudi) natalensis snails with miracidia of Fasciola hepatica revealed neither cercariae nor larval stages shed. Infection of white mice with metacercariae from field-collected snails proved to be negative for Fasciola eggs and immature juveniles or adults after 84 days post infection. The infection of eight rabbits (Oryctolagus cuniculus) has succeeded; two rabbits were infected, with a very low infection rate. Faeces of rabbits were negative for eggs. The worm burden was one and three worms from 40 fed metacercariae. The obtained fluke measures 23 mm in length by 4 mm in width. The tegument is covered with sharp-ending spines. The uterus contains few eggs. The intrauterine eggs measured 158 microm x 80 microm. According to the morphological characters of these flukes, they belong to F. gigantica.

  18. MODULATION OF DEFENSIVE REFLEX CONDITIONING IN SNAILS BY SEROTONIN

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    Vyatcheslav V Andrianov

    2015-10-01

    Full Text Available We studied the role of serotonin in the mechanisms of learning in terrestrial snails. To produce a serotonin deficit, the neurotoxic analogues of serotonin, 5,6- or 5,7-dihydroxytryptamine (5,6/5,7-DHT were used. Injection of 5,6/5,7-DHT was found to disrupt defensive reflex conditioning. Within two weeks of neurotoxin application, the ability to learn had recovered. Daily injection of serotonin before a training session accelerated defensive reflex conditioning and daily injections of 5-HTP in snails with a deficiency of serotonin induced by 5,7-DHT restored the snail’s ability to learn. We discovered that injections of the neurotoxins 5,6/5,7-DHT as well as serotonin, caused a decrease in the resting and threshold potentials of the premotor interneurons LPa3 and RPa3.

  19. Activity of the mangrove snail Cerithidea decollata (Gastropoda: Potamididae) in a warm temperate South African estuary

    Science.gov (United States)

    Hodgson, Alan N.; Dickens, John

    2012-08-01

    A population of Cerithidea decollata, an intertidal marine gastropod usually found within mangroves, was studied within an area of Juncus kraussii in the upper reaches of the warm temperate Knysna estuary, which is at the southern-most limit of the recorded distribution of this snail. Activity (migratory and homing behaviour, distances travelled during foraging) of the snails was monitored over spring and neap tides in four seasons. Migratory patterns of the snails were affected by season, time of low tide (day vs night), tidal magnitude (spring vs neap) and zonation. In the summer and spring, a greater proportion of snails migrated from J. kraussii leaves onto the mud during the day at spring low tide. During neap tides in these two seasons, most snails did not climb J. kraussii leaves and remained on the mud, which was nearly always exposed. In autumn a few snails only were active and in winter snails were almost completely inactive, probably due to low air temperatures. Snails travelled greater distances on the mud on spring tides, during the diurnal low tides, and in the summer. No snails were found to home to individual J. kraussii leaves; however, homing behaviour was recorded to wooden poles within the Juncus wetland.

  20. Action of SNAIL1 in Cardiac Myofibroblasts Is Important for Cardiac Fibrosis following Hypoxic Injury

    Science.gov (United States)

    Biswas, Hirak; Longmore, Gregory D.

    2016-01-01

    Hypoxic injury to the heart results in cardiac fibrosis that leads to cardiac dysfunction and heart failure. SNAIL1 is a zinc finger transcription factor implicated in fibrosis following organ injury and cancer. To determine if the action of SNAIL1 contributed to cardiac fibrosis following hypoxic injury, we used an endogenous SNAIL1 bioluminescence reporter mice, and SNAIL1 knockout mouse models. Here we report that SNAIL1 expression is upregulated in the infarcted heart, especially in the myofibroblasts. Utilizing primary cardiac fibroblasts in ex vivo cultures we find that pro-fibrotic factors and collagen I increase SNAIL1 protein level. SNAIL1 is required in cardiac fibroblasts for the adoption of myofibroblast fate, collagen I expression and expression of fibrosis-related genes. Taken together this data suggests that SNAIL1 expression is induced in the cardiac fibroblasts after hypoxic injury and contributes to myofibroblast phenotype and a fibrotic scar formation. Resultant collagen deposition in the scar can maintain elevated SNAIL1 expression in the myofibroblasts and help propagate fibrosis. PMID:27706205

  1. Fluctuating helical asymmetry and morphology of snails (Gastropoda in divergent microhabitats at 'Evolution Canyons I and II,' Israel.

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    Shmuel Raz

    Full Text Available BACKGROUND: Developmental instability of shelled gastropods is measured as deviations from a perfect equiangular (logarithmic spiral. We studied six species of gastropods at 'Evolution Canyons I and II' in Carmel and the Galilee Mountains, Israel, respectively. The xeric, south-facing, 'African' slopes and the mesic, north-facing, 'European' slopes have dramatically different microclimates and plant communities. Moreover, 'Evolution Canyon II' receives more rainfall than 'Evolution Canyon I.' METHODOLOGY/PRINCIPAL FINDINGS: We examined fluctuating asymmetry, rate of whorl expansion, shell height, and number of rotations of the body suture in six species of terrestrial snails from the two 'Evolution Canyons.' The xeric 'African' slope should be more stressful to land snails than the 'European' slope, and 'Evolution Canyon I' should be more stressful than 'Evolution Canyon II.' Only Eopolita protensa jebusitica showed marginally significant differences in fluctuating helical asymmetry between the two slopes. Contrary to expectations, asymmetry was marginally greater on the 'European' slope. Shells of Levantina spiriplana caesareana at 'Evolution Canyon I,' were smaller and more asymmetric than those at 'Evolution Canyon II.' Moreover, shell height and number of rotations of the suture were greater on the north-facing slopes of both canyons. CONCLUSIONS/SIGNIFICANCE: Our data is consistent with a trade-off between drought resistance and thermoregulation in snails; Levantina was significantly smaller on the 'African' slope, for increasing surface area and thermoregulation, while Eopolita was larger on the 'African' slope, for reducing water evaporation. In addition, 'Evolution Canyon I' was more stressful than Evolution Canyon II' for Levantina.

  2. Bioconcentration ratio of diazinon by freshwater fish and snail.

    Science.gov (United States)

    Kanazawa, J

    1978-11-01

    The bioconcentration ratios of diazinon from water by freshwater fishes were generally larger than that of crayfish and snails. Among fishes, the bioconcentration ratio of diazinon by topmouth gudgeon was the highest value, 152 being average. However, elimination of diazinon from fish body was linearly rapid. The influence of test concentration centration ratio of diazinon in whole body of topmouth gudgeon was increased proportional to the body weight.

  3. Indiscriminate males: mating behaviour of a marine snail compromised by a sexual conflict?

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    Kerstin Johannesson

    Full Text Available BACKGROUND: In promiscuous species, male fitness is expected to increase with repeated matings in an open-ended fashion (thereby increasing number of partners or probability of paternity whereas female fitness should level out at some optimal number of copulations when direct and indirect benefits still outweigh the costs of courtship and copulation. After this fitness peak, additional copulations would incur female fitness costs and be under opposing selection. Hence, a sexual conflict over mating frequency may evolve in species where females are forced to engage in costly matings. Under such circumstance, if females could avoid male detection, significant fitness benefits from such avoidance strategies would be predicted. METHODOLOGY/PRINCIPAL FINDINGS: Among four Littorina species, one lives at very much higher densities and has a longer mating season than the other three species. Using video records of snail behaviour in a laboratory arena we show that males of the low-density species discriminate among male and female mucous trails, trailing females for copulations. In the high-density species, however, males fail to discriminate between male and female trails, not because males are unable to identify female trails (which we show using heterospecific females, but because females do not, as the other species, add a gender-specific cue to their trail. CONCLUSIONS/SIGNIFICANCE: We conclude that there is likely a sexual conflict over mating frequency in the high-density species (L. saxatilis owing to females most likely being less sperm-limited in this species. This has favoured the evolution of females that permanently or optionally do not release a cue in the mucus to decrease excessive and costly matings resulting in unusually high frequencies of male-male copulating attempts in the wild. This is one of few examples of masking gender identity to obtain fewer matings.

  4. Fasciola hepatica: comparative metacercarial productions in experimentally-infected Galba truncatula and Pseudosuccinea columella.

    Science.gov (United States)

    Vignoles, Philippe; Dreyfuss, Gilles; Rondelaud, Daniel

    2015-01-01

    As large numbers of metacercariae of Fasciola hepatica are necessary for research, experimental infections of Galba truncatula and Pseudosuccinea columella with this digenean were carried out to determine the better intermediate host for metacercarial production and, consequently, the most profitable snail for decreasing the cost price of these larvae. Pre-adult snails (4 mm in shell height) originating from two populations per lymnaeid species were individually exposed to two or five miracidia, raised at 23 °C and followed for cercarial shedding up to their death. Compared to values noted in G. truncatula, the survival of P. columella on day 30 post-exposure was significantly greater, while the prevalence of F. hepatica infection was significantly lower. In the four P. columella groups, metacercarial production was significantly greater than that noted in the four groups of G. truncatula (347-453 per cercariae-shedding snail versus 163-275, respectively). Apart from one population of G. truncatula, the use of five miracidia per snail at exposure significantly increased the prevalence of F. hepatica in P. columella and the other population of G. truncatula, whereas it did not have any clear effect on the mean number of metacercariae. The use of P. columella for experimental infections with F. hepatica resulted in significantly higher metacercarial production than that noted with G. truncatula, in spite of a lower prevalence for the former lymnaeid. This finding allows for a significant decrease in the cost price of these larvae for commercial production.

  5. Fasciola hepatica: comparative metacercarial productions in experimentally-infected Galba truncatula and Pseudosuccinea columella

    Directory of Open Access Journals (Sweden)

    Vignoles Philippe

    2015-01-01

    Full Text Available As large numbers of metacercariae of Fasciola hepatica are necessary for research, experimental infections of Galba truncatula and Pseudosuccinea columella with this digenean were carried out to determine the better intermediate host for metacercarial production and, consequently, the most profitable snail for decreasing the cost price of these larvae. Pre-adult snails (4 mm in shell height originating from two populations per lymnaeid species were individually exposed to two or five miracidia, raised at 23 °C and followed for cercarial shedding up to their death. Compared to values noted in G. truncatula, the survival of P. columella on day 30 post-exposure was significantly greater, while the prevalence of F. hepatica infection was significantly lower. In the four P. columella groups, metacercarial production was significantly greater than that noted in the four groups of G. truncatula (347–453 per cercariae-shedding snail versus 163–275, respectively. Apart from one population of G. truncatula, the use of five miracidia per snail at exposure significantly increased the prevalence of F. hepatica in P. columella and the other population of G. truncatula, whereas it did not have any clear effect on the mean number of metacercariae. The use of P. columella for experimental infections with F. hepatica resulted in significantly higher metacercarial production than that noted with G. truncatula, in spite of a lower prevalence for the former lymnaeid. This finding allows for a significant decrease in the cost price of these larvae for commercial production.

  6. Antioxidant defenses and metabolic depression. The hypothesis of preparation for oxidative stress in land snails.

    Science.gov (United States)

    Hermes-Lima, M; Storey, J M; Storey, K B

    1998-07-01

    The roles of enzymatic antioxidant defenses in the natural tolerance of environmental stresses that impose changes in oxygen availability and oxygen consumption on animals is discussed with a particular focus on the biochemistry of estivation and metabolic depression in pulmonate land snails. Despite reduced oxygen consumption and PO2 during estivation, which should also mean reduced production of oxyradicals, the activities of antioxidant enzymes, such as superoxide dismutase and catalase, increased in 30 day-estivating snails. This appears to be an adaptation that allows the snails to deal with oxidative stress that takes place during arousal when PO2 and oxygen consumption rise rapidly. Indeed, oxidative stress was indicated by increased levels of lipid peroxidation damage products accumulating in hepatopancreas within minutes after arousal was initiated. The various metabolic sites responsible for free radical generation during arousal are still unknown but it seems unlikely that the enzyme xanthine oxidase plays any substantial role in this despite being implicated in oxidative stress in mammalian models of ischemia/reperfusion. We propose that the activation of antioxidant defenses in the organs of Otala lactea during estivation is a preparative mechanism against oxidative stress during arousal. Increased activities of antioxidant enzymes have also observed under other stress situations in which the actual production of oxyradicals should decrease. For example, antioxidant defenses are enhanced during anoxia exposure in garter snakes Thamnophis sirtalis parietalis (10 h at 5 degrees C) and leopard frogs Rana pipiens (30 h at 5 degrees C) and during freezing exposure (an ischemic condition due to plasma freezing) in T. sirtalis parietalis and wood frogs Rana sylvatica. It seems that enhancement of antioxidant enzymes during either anoxia or freezing is used as a preparatory mechanism to deal with a physiological oxidative stress that occurs rapidly within the

  7. Impact of the age of Biomphalaria alexandrina snails on Schistosoma mansoni transmission: modulation of the genetic outcome and the internal defence system of the snail

    Directory of Open Access Journals (Sweden)

    Iman Fathy Abou-El-Naga

    2015-08-01

    Full Text Available Of the approximately 34 identified Biomphalariaspecies,Biomphalaria alexandrinarepresents the intermediate host of Schistosoma mansoniin Egypt. Using parasitological and SOD1 enzyme assay, this study aimed to elucidate the impact of the age of B. alexandrinasnails on their genetic variability and internal defence against S. mansoniinfection. Susceptible and resistant snails were reared individually for self-reproduction; four subgroups of their progeny were used in experiment. The young susceptible subgroup showed the highest infection rate, the shortest pre-patent period, the highest total cercarial production, the highest mortality rate and the lowest SOD1 activity. Among the young and adult susceptible subgroups, 8% and 26% were found to be resistant, indicating the inheritance of resistance alleles from parents. The adult resistant subgroup, however, contained only resistant snails and showed the highest enzyme activity. The complex interaction between snail age, genetic background and internal defence resulted in great variability in compatibility patterns, with the highest significant difference between young susceptible and adult resistant snails. The results demonstrate that resistance alleles function to a greater degree in adults, with higher SOD1 activity and provide potential implications for Biomphalariacontrol. The identification of the most susceptible snail age enables determination of the best timing for applying molluscicides. Moreover, adult resistant snails could be beneficial in biological snail control.

  8. Biological studies on the snail intermediate hosts of schistosomiasis with a special emphasis on using larval echinostomes as biocontrol agent against larval schistosomes and snails.

    Science.gov (United States)

    Rashed, A A

    2002-12-01

    The present investigation deals with the infectivity of the two snail intermediate hosts of schistosomiasis, Biomphalaria alexandrina and Bulinus truncatus collected from nine drains in Sharkia Governorate, Egypt. The rate of infection among the snails was general low being 0% in many drains. Regarding B. alexandrina, the rate of infection ranged from 4-16%, and in B. truncatus ranged from 4-8%. Infection with larval echinostomes was dominant over larval schistosomes in the two snail vectors. The distribution of larval schistosomes was restricted to the hepatopancreas of the two snail vectors, while larval echinostomes were distributed in head, foot, kidney, haemocoelic cavity, hepatopancreas...etc. The predation of larval schistosomes by larval echinostomes and the severe histopathological effects induced by larval ecbinostomes strongly enhances using them as biocontrol agent. The physico-chemical parameters and pollution condition in the drains seem to have no effect on the process of snails infectivity. It is concluded that larval echinostomes can resist the polluting conditions in the drain. The two snail vectors exhibit very minimal or rare host response against larval echinostomes. Probably, the toxicants and pollutants in the drain may act as stressor that makes the snails much more susceptible to infection by larval trematodes.

  9. Neuro-endocrine control of reproduction in hermaphroditic freshwater snails: mechanisms and evolution

    Directory of Open Access Journals (Sweden)

    Joris M Koene

    2010-10-01

    Full Text Available Invertebrates are used extensively as model species to investigate neuro-endocrine processes regulating behaviours, and many of these processes may be extrapolated to vertebrates. However, when it comes to reproductive processes, many of these model species differ notably in their mode of reproduction. A point in case are simultaneously hermaphroditic molluscs. In this review I aim to achieve two things. On the one hand, I provide a comprehensive overview of the neuro-endocrine control of male and female reproductive processes in freshwater snails. Even though the focus will necessarily be on Lymnaea stagnalis, since this is the best-studied species in this respect, extensions to other species are made wherever possible. On the other hand, I will place these findings in the actual context of the whole animal, after all these are simultaneous hermaphrodites. By considering the hermaphroditic situation, I uncover a numbers of possible links between the regulation of the two reproductive systems that are present within this animal, and suggest a few possible mechanisms via which this animal can effectively switch between the two sexual roles in the flexible way that it does. Evidently, this opens up a number of new research questions and areas that explicitly integrate knowledge about behavioural decisions (e.g., mating, insemination, egg laying and sexual selection processes (e.g., mate choice, sperm allocation with the actual underlying neuronal and endocrine mechanisms required for these processes to act and function effectively.

  10. Perspectives on land snails - sampling strategies for isotopic analyses

    Science.gov (United States)

    Kwiecien, Ola; Kalinowski, Annika; Kamp, Jessica; Pellmann, Anna

    2017-04-01

    Since the seminal works of Goodfriend (1992), several substantial studies confirmed a relation between the isotopic composition of land snail shells (d18O, d13C) and environmental parameters like precipitation amount, moisture source, temperature and vegetation type. This relation, however, is not straightforward and site dependent. The choice of sampling strategy (discrete or bulk sampling) and cleaning procedure (several methods can be used, but comparison of their effects in an individual shell has yet not been achieved) further complicate the shell analysis. The advantage of using snail shells as environmental archive lies in the snails' limited mobility, and therefore an intrinsic aptitude of recording local and site-specific conditions. Also, snail shells are often found at dated archaeological sites. An obvious drawback is that shell assemblages rarely make up a continuous record, and a single shell is only a snapshot of the environmental setting at a given time. Shells from archaeological sites might represent a dietary component and cooking would presumably alter the isotopic signature of aragonite material. Consequently, a proper sampling strategy is of great importance and should be adjusted to the scientific question. Here, we compare and contrast different sampling approaches using modern shells collected in Morocco, Spain and Germany. The bulk shell approach (fine-ground material) yields information on mean environmental parameters within the life span of analyzed individuals. However, despite homogenization, replicate measurements of bulk shell material returned results with a variability greater than analytical precision (up to 2‰ for d18O, and up to 1‰ for d13C), calling for caution analyzing only single individuals. Horizontal high-resolution sampling (single drill holes along growth lines) provides insights into the amplitude of seasonal variability, while vertical high-resolution sampling (multiple drill holes along the same growth line

  11. Molecular characterisation of Galba truncatula, Lymnaea neotropica and L. schirazensis from Cajamarca, Peru and their potential role in transmission of human and animal fascioliasis.

    Science.gov (United States)

    Bargues, M Dolores; Artigas, Patricio; Khoubbane, Messaoud; Ortiz, Pedro; Naquira, Cesar; Mas-Coma, Santiago

    2012-08-15

    Human and animal fascioliasis is emerging in many world regions, among which Andean countries constitute the largest regional hot spot and Peru the country presenting more human endemic areas. A survey was undertaken on the lymnaeid snails inhabiting the hyperendemic area of Cajamarca, where human prevalences are the highest known among the areas presenting a "valley transmission pattern", to establish which species are present, genetically characterise their populations by comparison with other human endemic areas, and discuss which ones have transmission capacity and their potential implications with human and animal infection. Therefore, ribosomal DNA ITS-2 and ITS-1, and mitochondrial DNA 16S and cox1 were sequenced by the dideoxy chain-termination method. Results indicate the presence of three, morphologically similar, small lymnaeid species belonging to the Galba/Fossaria group: Galba truncatula, Lymnaea neotropica and L. schirazensis. Only one combined haplotype for each species was found. The ITS-1, 16S and cox1 haplotypes of G. truncatula are new. No new haplotypes were found in the other two species. This scenario changes previous knowledge, in which only L. viator (= L. viatrix) was mentioned. Galba truncatula appears to be the most abundant, with high population densities and evident anthropophyly including usual presence in human neighbourhood. Infection by Fasciola hepatica larval stages were molecularly confirmed in two populations of this species. The nearness between G. truncatula populations presenting liver fluke infection and both human settings and schools for children, together with the absence of populations of other lymnaeid species in the locality, suggest a direct relationship with human infection. The geographical overlap of three lymnaeid species poses problems for epidemiological studies and control action. First, a problem in classifying lymnaeid specimens in both field and laboratory activities, given their transmission capacity

  12. Effects of silver nanoparticles on the freshwater snail Physa acuta: The role of test media and snails' life cycle stage.

    Science.gov (United States)

    F Gonçalves, Sandra; D Pavlaki, Maria; Lopes, Rafael; Hammes, Julia; Gallego-Urrea, Julián Alberto; Hassellöv, Martin; Jurkschat, Kerstin; Crossley, Alison; Loureiro, Susana

    2017-01-01

    Silver nanoparticles (AgNPs) are widely used worldwide, most likely leading to their release into the environment and a subsequent increase of environmental concentrations. Studies of their deleterious effects on organisms is crucial to understand their environmental impacts. The freshwater snail Physa acuta was chosen to evaluate the potential deleterious effects of AgNPs and their counterpart AgNO3 , through water-only exposures. The toxicity of AgNPs is greatly influenced by medium composition. Thus, 2 media were tested: artificial pond water (APW) and modified APW (adapted by removing calcium chloride). Acute tests (96 h) were performed with juvenile and adult snails in both media to assess lethality, and egg mass chronic tests were conducted with APW medium only to assess embryo viability and mortality, carried out until 90% hatching success was reached in the control. Acute toxicity increased with decreasing shell length for both silver forms (ion and nanoparticle); that is, juveniles were more sensitive than adults. Different test media led to dissimilar median lethal concentrations, with chloride playing an important role in toxicity, most likely by complexation with silver ions, which would reduce the bioavailability, uptake, and toxicity of silver. Chronic tests showed that hatching success was more sensitive to silver in the ionic form than in the particulate form. Different forms of silver, exposure media, and life cycle stages led to different patterns of toxicity, highlighting an impairment in the snails' life cycle. Environ Toxicol Chem 2017;36:243-253. © 2016 SETAC.

  13. THE BIOCIDE TRIBUTYLTIN REDUCES THE ACCUMULATION OF TESTOSTERONE AS FATTY ACID ESTERS IN THE MUD SNAIL (ILYANASSA OBSOLETA)

    Science.gov (United States)

    Imposex, the development of male sex characteristics by female gonochoristic snails, has been documented globally and is causally associated with exposure to the ubiquitous environmental contaminant tributyltin (TBT). Elevated testosterone levels in snails also are associated wit...

  14. THE BIOCIDE TRIBUTYLTIN REDUCES THE ACCUMULATION OF TESTOSTERONE AS FATTY ACID ESTERS IN THE MUD SNAIL (ILYANASSA OBSOLETA)

    Science.gov (United States)

    Imposex, the development of male sex characteristics by female gonochoristic snails, has been documented globally and is causally associated with exposure to the ubiquitous environmental contaminant tributyltin (TBT). Elevated testosterone levels in snails also are associated wit...

  15. Aquatic snails from mining sites have evolved to detect and avoid heavy metals.

    Science.gov (United States)

    Lefcort, H; Abbott, D P; Cleary, D A; Howell, E; Keller, N C; Smith, M M

    2004-05-01

    Toxicants in polluted environments are often patchily distributed. Hence, rather than being passive absorbers of pollution, some organisms have evolved the ability to detect and avoid toxicants. We studied the avoidance behavior of Physella columbiana, an aquatic pulmonate snail, in a pond that has been polluted with heavy metals for more than 120 years. Populations of this snail are rare at reference sites and are only robust at heavy-metal-polluted sites. We hypothesized that the snails are able to persist because they have evolved the ability to minimize their exposure to metals by actively avoiding metals in their environment. Using a Y-maze flow tank, we tested the avoidance behavior of snails to heavy-metal-polluted sediments and single-metal solutions of cadmium, zinc, or lead. We also tested the avoidance behaviors of the snails' laboratory-reared offspring raised in nonpolluted conditions. In addition, we tested the avoidance behavior of a small population of snails from a reference pond. Although all the snails we tested were able to detect low concentrations of heavy metals, we found that snails from the polluted site were the most sensitive, that their offspring were somewhat less sensitive, and that snails from the reference site were the least sensitive. This suggests that the ability of polluted-site snails to avoid heavy metals is both genetic and environmental. The concentrations of metals avoided by the snails from the polluted site were below the levels found at hot spots within their natal pond. The snails may be able to persist at this site because they decrease their exposure by moving to less-polluted sections of the pond. One application of our findings is the use of aquatic snails and our Y-maze design as an inexpensive pollution detector. Environmental pollutants such as lead, zinc, and arsenic are a problem throughout the world. People in underdeveloped countries often lack sophisticated pollution detection devices. We have developed a

  16. MiR-22 inhibits lung cancer cell EMT and invasion through targeting Snail.

    Science.gov (United States)

    Zhang, K; Li, X-Y; Wang, Z-M; Han, Z-F; Zhao, Y-H

    2017-08-01

    Snail is an important factor in regulating epithelial mesenchymal transition (EMT). Its elevation is related to the enhancement of lung cancer invasion. MicroRNA-22 (MiR-22) plays a role in regulating lung cancer cell invasion. Bioinformatics analysis showed the complementary binding site between miR-22 and Snail. This study aimed to investigate the role of miR-22 in regulating Snail and affecting lung cancer cell invasion and metastasis. Dual luciferase assay confirmed the targeted relationship between miR-22 and Snail. MiR-22 and Snail expressions were compared in MRC-5, Anip973, and AGZY83-a cells. Cell colony formation and invasion were tested in Anip973 and AGYZ83-a cells. Anip973 and AGYZ83-a cells were treated by 5 ng/ml transforming growth factor β1 (TGF-β1) to detect miR-22, Snail, E-cadherin, and N-cadherin expressions. Anip973 cells were cultured in vitro and divided into five groups, including miR-Normal control (miR-NC), miR-22 mimic, small interfering RNA-Normal control (si-NC), si-Snail, and miR-22 mimic + si-Snail groups. MiR-22 targeted inhibited Snail expression. MiR-22 significantly down-regulated, while Snail obviously elevated in Anip973 and AGYZ83-a cells compared with that in MRC-5 cells. Anip973 exhibited markedly stronger invasive and colony formation abilities than AGYZ83-a. TGFβ1 apparently reduced miR-22 and E-cadherin, whereas increased Snail and N-cadherin stronger in Anip973 than that in AGYZ83-a. MiR-22 mimic and/or si-Snail transfection significantly reduced Snail and N-cadherin levels, up-regulated E-cadherin expression, and attenuated cell colony formation and invasion. Down-regulation of miR-22 plays a role in facilitating lung cancer cell EMT and invasion by elevating Snail. MiR-22 over-expression attenuated lung cancer cell EMT and invasion via targeted inhibiting Snail.

  17. A new freshwater snail genus (Hydrobiidae, Gastropoda from Montenegro, with a discussion on gastropod diversity and endemism in Skadar Lake

    Directory of Open Access Journals (Sweden)

    Vladimir Pesic

    2013-03-01

    Full Text Available Karucia sublacustrina a new species of freshwater snails (Hydrobiidae, Gastropoda is described based on material collected from Skadar Lake (Montenegro, Albania. The new species belongs to monotypic genus Karucia gen. n. The shell morphology and body shape of the new genus resembles Radomaniola Szarowska, 2006 and Grossuana Radoman, 1973, from which it differs in the larger shells with relatively slim and a slightly, but clearly shouldered body whorl. The number of gastropods from Skadar Lake basin tallies now 50 species. The adjusted rate of gastropod endemicity for Skadar Lake basin is estimated to be 38%. By compiling faunal and taxonomic data we also aim to provide information of relevance as to conservation efforts.

  18. Snail transcription factor negatively regulates maspin tumor suppressor in human prostate cancer cells

    Directory of Open Access Journals (Sweden)

    Neal Corey L

    2012-08-01

    Full Text Available Abstract Background Maspin, a putative tumor suppressor that is down-regulated in breast and prostate cancer, has been associated with decreased cell motility. Snail transcription factor is a zinc finger protein that is increased in breast cancer and is associated with increased tumor motility and invasion by induction of epithelial-mesenchymal transition (EMT. We investigated the molecular mechanisms by which Snail increases tumor motility and invasion utilizing prostate cancer cells. Methods Expression levels were analyzed by RT-PCR and western blot analyses. Cell motility and invasion assays were performed, while Snail regulation and binding to maspin promoter was analyzed by luciferase reporter and chromatin immunoprecipitation (ChIP assays. Results Snail protein expression was higher in different prostate cancer cells lines as compared to normal prostate epithelial cells, which correlated inversely with maspin expression. Snail overexpression in 22Rv1 prostate cancer cells inhibited maspin expression and led to increased migration and invasion. Knockdown of Snail in DU145 and C4-2 cancer cells resulted in up-regulation of maspin expression,