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Sample records for pseudosuccinea columella snails

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

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    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.

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

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    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

  3. Effect of Fascioloides magna (Digenea) on fecundity, shell height, and survival rate of Pseudosuccinea columella (Lymnaeidae).

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    Pankrác, Jan; Novobilský, Adam; Rondelaud, Daniel; Leontovyč, Roman; Syrovátka, Vít; Rajský, Dušan; Horák, Petr; Kašný, Martin

    2016-08-01

    Infection with Fascioloides magna (Digenea) causes serious damage to liver tissue in definitive hosts represented by ruminants, especially cervids. The distribution of F. magna includes the indigenous areas in North America, and the areas to which F. magna was introduced-Central Europe, Southeast Europe, and Italy. The North American intermediate host of F. magna, the freshwater snail Pseudosuccinea columella (Lymnaeidae), is an invasive species recorded in South America, the Caribbean, Africa, Australia, and west and Southeast Europe. In Europe, Galba truncatula is the snail serving for transmission, but P. columella has potential to become here a new intermediate host of F. magna. Little is known about interactions between F. magna and P. columella. In this study, the susceptibility of P. columella (Oregon, USA) to the infection by a single miracidium of the Czech strain of F. magna and the influence of F. magna on snail fecundity, shell height, and survival were evaluated. The data show that the Oregon strain of P. columella is a highly suitable host for the Czech strain of F. magna, with the infection rate of 74 %. In addition, a negative effect on survival rate of infected snails was recorded only in the late phase of infection. The infection was accompanied by a major reduction in egg mass production and by a decrease in the number of eggs per egg mass. The shell height of infected snails did not significantly differ from that in unexposed controls.

  4. The effect of isolation on the life-history traits of Pseudosuccinea columella (Pulmonata: Lymnaeidae

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    Alfredo Gutiérrez

    2001-05-01

    Full Text Available A population of Pseudosuccinea columella was raised under laboratory conditions and its life tables were determined in isolated and paired snails. Isolated snails were significantly larger in shell size than paired snails from five weeks of age onward. Also, statistically significant differences were found for the number of eggs per mass per individual from week 5 to 9, isolated snails exhibiting the highest values. The intrinsic and finite rates of increase were greater in isolated than in paired snails. Either an inhibition of the reproductive output between individuals or the advantage of selfing may be the cause of the differences in this species, acting as a possible mechanism that increase the fitness of isolated snails.

  5. Fasciola hepatica: comparative metacercarial productions in experimentally-infected Galba truncatula and Pseudosuccinea columella

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    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. The effect of spirulina (Arthrospira platensis (Oscillatoriales: Cyanobacteria on the experimental breeding of Pseudosuccinea columella (Basommatophora: Lymnaeidae

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    Lucila Prepelitchi

    2015-06-01

    Full Text Available Snails of the family Lymnaeidae, as Pseudosuccinea columella, are the intermediate hosts of Fasciola hepatica, the causative agent of fasciolosis in human and livestock all over the world. A thorough knowledge of snail biology is essential for describing the transmission dynamics and for controlling this disease. Since food quality has had a significant effect on snail growth, fecundity and fertility, in this study we evaluated the use of spirulina (Arthrospira platensis as a food resource for the artificial breeding of P. columella, an invasive snail and the main intermediate host of F. hepatica in Northeastern Argentina. The main purpose was to measure the effect of spirulina on fitness parameters such as survival rate, growth rate, size at first reproduction, lifetime fecundity and viable offspring. A total of 20 676 newly-laid F2 eggs were used; half of them were fed with lettuce (treatment L and the other half with lettuce plus spirulina (treatment L+S. In comparison with P. columella snails fed only with lettuce, we found that P. columella fed with lettuce plus spirulina: 1 showed higher survival rates, 2 grew faster and showed higher growth increments, 3 attained sexual maturity earlier in time (L+S:60 days vs. L:120 days and at a smaller size (L+S:4.8mm vs. L:8.2mm, 4 had a longer reproductive period (L+S:150 days vs. L:90 days, 5 produced a higher number of eggs/snail (L+S:29.6 vs. L:13.3, and 6 showed a higher offspring hatching rate (L+S:70% vs. L:40%. The supplementation of P. columella diet with commercial spirulina enhances it fitness and improved the artificial breeding of this species. Spirulina may have a direct positive effect on P. columella development by consuming it, along with an indirect positive effect by improving the water quality. This rearing technique provided large number of reproducing adults and a continuous production of offspring, which are essential for developing future experimental studies in order to

  7. 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

  8. 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

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    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

  9. Ocorrência de infecção natural de Fasciola hepatica Linnaeus, 1758 em Lymnaea columella Say, 1817 no Vale do Paraíba, SP, Brasil Natural infection by Fasciola hepatica in Lymnaea columella in the Paraíba river valley, S. Paulo, Brazil

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    Marlene Tiduko Ueta

    1980-06-01

    Full Text Available Foram registradas em Piquete, no vale do rio Paraíba do Sul (SP, Brasil, taxas de 1,22% e 0,14% de infecção natural em Lymnaea columella, por Fasciola hepatica. Em um único exemplar de Lymnaea columella dentre os 1.052 examinados, foram observadas rédias com xifidiocercárias, rédias com cercárias de Fasciola hepatica e metacercárias de Echinostomatidae.Infection rates of 1.22% and 0.14% were obtained in Lymnaea columella snails naturally infected by Fasciola hepatica. Samples of the snails were collected in Piquete, a municipality of Paraíba do Sul, a river valley area in the State of S. Paulo. Also observed was one of the 1052 specimen of the Lymnaea columella rediae which had xiphidiocercariae and rediae with Fasciola hepatica cercariae and metacercariae of Echinostomatidae.

  10. First report of Lymnaea columella Say, 1817 (Pulmonata: Lymnaeidae naturally infected with Fasciola hepatica (Linnaeus,1758 (Trematoda: Digenea in Argentina

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    Prepelitchi Lucila

    2003-01-01

    Full Text Available We report the first evidence of natural infection of Lymnaea columella with Fasciola hepatica in Argentina. A sample of 601 snails was collected in May 2003 in northeastern Corrientes, a province bounded on the north by Paraguay, on the east by Brazil and on the southeast by Uruguay. Among 500 examined snails, 44 (8.8% were exclusively infected with F. hepatica. Parasite identification was based on morphological features of cercariae from snails, and of eggs and adult flukes from Wistar rats. We discuss the events suggesting that an enzootic transmission cycle of F. hepatica has been recently established in northeastern Corrientes.

  11. Aspects of the Maintenance of the Life Cycle of Fasciola hepatica in Lymnaea columella in Minas Gerais, Brazil

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    Souza Cecília Pereira de

    2002-01-01

    Full Text Available Fascioliasis is a parasitic disease of domestic ruminants that occurs worldwide. The lymnaeid intermediate hosts of Fasciola hepatica include Lymnaea columella, which is widely distributed in Brazil. A colony of L. columella from Belo Horizonte, MG, was reared in our laboratory to be used in studies of the F. hepatica life cycle, the intermediate host-parasite relationship and development of an anti-helminthic vaccine. In the first experiment 1,180 snails were exposed to miracidia of F. hepatica eggs removed from the biliary tracts of cattle from the State of Rio Grande do Sul. In the second and third experiments the snails were exposed to miracidia that had emerged from F. hepatica eggs from Uruguay, maintained in rabbits. The rates of infection in the first, second and third experiments were 0, 42.1 and 0% respectively. Over 15,806 metacercariae were obtained and stored at 4ºC. Four rabbits weighing 1.5 kg each were infected with 32-44 metacercariae and two with 200. Three rabbits begin to eliminate eggs of the parasite in the feces from 84 days after infection onwards. The biological cycle of F. hepatica in L. columella and the rabbit was completed within 124 days.

  12. Molluscicidal potential of Heterorhabditis baujardi (Rhabditida: Heterorhabditidae), strain LPP7, on Lymnaea columella (Gastropoda: Pulmonata): An alternative for biological control of fasciolosis.

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    Tunholi, Victor Menezes; Lorenzoni, P O; da Silva, Ygor Henrique; Tunholi-Alves, Vinícius Menezes; Boeloni, Jankerle Neves; da Silva, Maria Aparecida; Monteiro, Caio Oliveira; Prata, M C A; Pinheiro, J; Martins, Isabella Vilhena Freire

    2017-09-01

    This study elucidated for the first time, under laboratory conditions, the susceptibility of Lymnaea columella to infective juveniles of Heterorhabditis baujardi LPP7. Exposure to the nematodes induced an average mortality rate of 66.66% in the population of L. columella, with the highest values attained from the second week after exposure onward. In addition, all the reproductive parameters analyzed (total number of eggs, number of egg masses, number of eggs laid/snail, embryo hatching rate and content of galactogen stored in the albumen gland) changed as a result of the infection. The results indicate the occurrence of the phenomenon of parasitic castration in L. columella infected by H. baujardi LPP7, probably through depletion of energy reserves such as galactogen, necessary to meet the intense metabolic demands of the nematode's larval stages. Finally, histopathological analysis demonstrated an intense process of cell disorganization, characterized by the occurrence of granulomatous inflammatory reactions in tissues of exposed snails, induced by the spoliative action of the bacteria/nematode. The results suggest the use of H. baujardi LPP7 as an alternative for biological control of the population of this intermediate host, and thus of the diseases in whose epidemiological chain it participates, especially fasciolosis, in line with the recommendations of the World Health Organization (WHO). Copyright © 2017. Published by Elsevier B.V.

  13. Calcium movement, graviresponsiveness and the structure of columella cells and columella tissues in roots of Allium cepa L

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    Moore, R.

    1985-01-01

    Roots of Allium cepa L. cv. Yellow are differentially responsive to gravity. Long (e.g. 40 mm) roots are strongly graviresponsive, while short (c.g. 4 mm) roots are minimally responsive to gravity. Although columella cells of graviresponsive roots are larger than those of nongraviresponsive roots, they partition their volumes to cellular organelles similarly. The movement of amyloplasts and nuclei in columella cells of horizontally-oriented roots correlates positively with the onset of gravicurvature. Furthermore, there is no significant difference in the rates of organellar redistribution when graviresponsive and nongraviresponsive roots are oriented horizontally. The more pronounced graviresponsiveness of longer roots correlates positively with (1) their caps being 9-6 times more voluminous, (2) their columella tissues being 42 times more voluminous, (3) their caps having 15 times more columella cells, and (4) their columella tissues having relative volumes 4.4 times larger than those of shorter, nongraviresponsive roots. Graviresponsive roots that are oriented horizontally are characterized by a strongly polar movement of 45Ca2+ across the root tip from the upper to the lower side, while similarly oriented nongraviresponsive roots exhibit only a minimal polar transport of 45Ca2+. These results indicate that the differential graviresponsiveness of roots of A. cepa is probably not due to either (1) ultrastructural differences in their columella cells, (2) differences in the rates of organellar redistribution when roots are oriented horizontally. Rather, these results indicate the graviresponsiveness may require an extensive columella tissue, which, in turn, may be necessary for polar movement of 45Ca2+ across the root tip.

  14. The morphogenesis of the avian Columella auris with special ...

    African Journals Online (AJOL)

    The columella auris of the ostrich is derived as in the crocodile from three sources; the two upper segments of the hyoid arch (pharyngohyal and epihyal) and a laterohyal component. The latter contributes the homologue of the crocodilian suprastapedial (or lacertilian intercalary) as well as the tympanic process and the ...

  15. Root graviresponsiveness and columella cell structure in carotenoid-deficient seedlings of Zea mays

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    Moore, R.; McClelen, C. E.

    1985-01-01

    Root graviresponsiveness in normal and carotenoid-deficient mutant seedlings of Zea mays was not significantly different. Columella cells in roots of mutant seedlings were characterized by fewer, smaller, and a reduced relative volume of plastids as compared to columella cells of normal seedlings. Plastids in columella cells of mutant seedlings possessed reduced amounts of starch. Although approximately 10 per cent of the columella cells in mutant seedlings lacked starch, their plastids were located at the bottom of the cell. These results suggest that (i) carotenoids are not necessary for root gravitropism, (ii) graviresponsiveness is not necessarily proportional to the size, number, or relative volume of plastids in columella cells, and (iii) sedimentation of plastids in columella cells may not result directly from their increased density due to starch content. Plastids in columella cells of normal and mutant seedlings were associated with bands of microtubule-like structures, suggesting that these structures may be involved in 'positioning' plastids in the cell.

  16. Snails home

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    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.

  17. The influence of gravity on the formation of amyloplasts in columella cells of Zea mays L

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    Moore, R.; Fondren, W. M.; Koon, E. C.; Wang, C. L.

    1986-01-01

    Columella (i.e., putative graviperceptive) cells of Zea mays seedlings grown in the microgravity of outer space allocate significantly less volume to putative statoliths (amyloplasts) than do columella cells of Earth-grown seedlings. Amyloplasts of flight-grown seedlings are significantly smaller than those of ground controls, as is the average volume of individual starch grains. Similarly, the relative volume of starch in amyloplasts in columella cells of flight-grown seedlings is significantly less than that of Earth-grown seedlings. Microgravity does not significantly alter the volume of columella cells, the average number of amyloplasts per columella cell, or the number of starch grains per amyloplast. These results are discussed relative to the influence of gravity on cellular and organellar structure.

  18. Detection of Lymnaea columella infection by Fasciola hepatica through Multiplex-PCR

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    Kelly Grace Magalhães

    2004-06-01

    Full Text Available From complete mitochondrial DNA sequence of Fasciola hepatica available in Genbank, specific primers were designed for a conserved and repetitive region of this trematode. A pair of primers was used for diagnosis of infected Lymnaea columella by F. hepatica during the pre-patent period simultaneously with another pair of primers which amplified the internal transcribed spacer (ITS region of rDNA from L. columella in a single Multiplex-PCR. The amplification generated a ladder band profile specific for F. hepatica. This profile was observed in positive molluscs at different times of infection, including adult worms from the trematode. The Multiplex-PCR technique showed to be a fast and safe tool for fascioliasis diagnosis, enabling the detection of F. hepatica miracidia in L. columella during the pre-patent period and identification of transmission areas.

  19. Models of Snail Locomotion

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    Chan, Brian; Hosoi, Anette

    2003-11-01

    All snails move over a thin layer of mucus using periodic deformations of their muscular foot. This unusual mode of locomotion can be modeled as a thin film of viscous fluid sandwiched between a flexible membrane and a rigid substrate. We present theoretical, numerical and experimental studies of locomotion via viscous stresses generated in thin films. Study of snail locomotion led us to design and construct several mechanical models: RoboSnail 1 which mimics snail locomotion incorrectly, but still proves to be a valid propulsion device over a thin viscous fluid layer and RoboSnail 2 which mimics land snails and uses forward-propagating compression waves on the base of the foot. Experimental results from the prototype machines are compared with long wavelength numerical and theoretical models.

  20. The Classroom Animal: Snails.

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    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)

  1. Influence of microgravity on root-cap regeneration and the structure of columella cells in Zea mays

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    Moore, R.; McClelen, C. E.; Fondren, W. M.; Wang, C. L.

    1987-01-01

    We launched imbibed seeds and seedlings of Zea mays into outer space aboard the space shuttle Columbia to determine the influence of microgravity on 1) root-cap regeneration, and 2) the distribution of amyloplasts and endoplasmic reticulum (ER) in the putative statocytes (i.e., columella cells) of roots. Decapped roots grown on Earth completely regenerated their caps within 4.8 days after decapping, while those grown in microgravity did not regenerate caps. In Earth-grown seedlings, the ER was localized primarily along the periphery of columella cells, and amyloplasts sedimented in response to gravity to the lower sides of the cells. Seeds germinated on Earth and subsequently launched into outer space had a distribution of ER in columella cells similar to that of Earth-grown controls, but amyloplasts were distributed throughout the cells. Seeds germinated in outer space were characterized by the presence of spherical and ellipsoidal masses of ER and randomly distributed amyloplasts in their columella cells. These results indicate that 1) gravity is necessary for regeneration of the root cap, 2) columella cells can maintain their characteristic distribution of ER in microgravity only if they are exposed previously to gravity, and 3) gravity is necessary to distribute the ER in columella cells of this cultivar of Z. mays.

  2. Limnaea peregrina Clessin, 1882, Synonym of Lymnaea columella Say, 1817 (Gastropoda: Lymnaeidae

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    W Lobato Paraense

    1994-12-01

    Full Text Available A description is given of the shell, radula, renal region, reproductive system and egg capsules of topotypic specimens of limnaea peregrina Clessin, 1882. This investigation intends contributing to define the specific identity of that nominal species. A close anatomical comparison with Lymnaea columella Say, 1817 from Michigan, USA, shows that both forms are indistinguishable, giving support to previous inferences from some authors. Data on egg hatching are presented.

  3. Photometric evaluation of bilateral cleft lip and palate patients after primary columella lengthening.

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    Meazzini, Maria Costanza; Rossetti, Giulia; Morabito, Alberto; Garattini, Giovanna; Brusati, Roberto

    2010-01-01

    To evaluate the results in terms of nasal esthetics of children with bilateral cleft lip and palate, operated with the Cutting primary columella lengthening technique, associated with Grayson orthopedic nasoalveolar molding, and to compare them with the nasal aspects of children with bilateral cleft lip and palate operated with a traditional approach and to an age-matched sample of normal Caucasian children. Normalized photogrammetry. Regional Center for CLP, Department of Maxillo-Facial Surgery, San Paolo Hospital, Milan. Three groups of patients 5 years of age. Cutting group: 18 patients treated with the Grayson-Cutting technique. Delaire group: 18 patients treated with the traditional Delaire technique. Normal children: 40 normal preschool children. With the Cutting-Grayson technique, the columella length, nasal tip angle, and protrusion are greatly improved compared with the previous protocol and are close to normal. On the other hand, the nasolabial angle and interalar distances are still excessively wide in both samples. Although this is not a long-term study, at this time none of the patients operated with this technique have needed secondary columella lengthening. On the other hand, although certainly improved, the nasal anatomy obtained is far from normal.

  4. Microgravity and clinorotation cause redistribution of free calcium in sweet clover columella cells

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    Hilaire, E.; Paulsen, A. Q.; Brown, C. S.; Guikema, J. A.; Spooner, B. S. (Principal Investigator)

    1995-01-01

    In higher plants, calcium redistribution is believed to be crucial for the root to respond to a change in the direction of the gravity vector. To test the effects of clinorotation and microgravity on calcium localization in higher plant roots, sweet clover (Melilotus alba L.) seedlings were germinated and grown for two days on a slow rotating clinostat or in microgravity on the US Space Shuttle flight STS-60. Subsequently, the tissue was treated with a fixative containing antimonate (a calcium precipitating agent) during clinorotation or in microgravity and processed for electron microscopy. In root columella cells of clinorotated plants, antimonate precipitates were localized adjacent to the cell wall in a unilateral manner. Columella cells exposed to microgravity were characterized by precipitates mostly located adjacent to the proximal and lateral cell wall. In all treatments some punctate precipitates were associated with vacuoles, amyloplasts, mitochondria, and euchromatin of the nucleus. A quantitative study revealed a decreased number of precipitates associated with the nucleus and the amyloplasts in columella cells exposed to microgravity as compared to ground controls. These data suggest that roots perceive a change in the gravitational field, as produced by clinorotation or space flights, and respond respectively differently by a redistribution of free calcium.

  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. A morphometric analysis of the redistribution of organelles in columella cells of horizontally-oriented roots of Zea mays

    Science.gov (United States)

    Moore, R.

    1986-01-01

    In order to determine what structural changes in graviperceptive cells are associated with onset of root gravicurvature, the redistribution of organelles in columella cells of horizontally-oriented, graviresponding roots of Zea mays has been quantified. Root gravicurvature began by 15 min after reorientation, and did not involve significant changes in the (i) volume of individual columella cells or amyloplasts, (ii) relative volume of any cellular organelle, (iii) number of amyloplasts per columella cell, or (iv) surface area of cellular location of endoplasmic reticulum. Sedimentation of amyloplasts began within 1 to 2 min after reorientation, and was characterized by an intensely staining area of cytoplasm adjacent to the sedimenting amyloplasts. By 5 min after reorientation, amyloplasts were located in the lower distal corner of columella cells, and, by 15 min after reorientation, overlaid the entire length of the lower cell wall. No consistent contact between amyloplasts and any cellular structure was detected at any stage of gravicurvature. Centrally-located nuclei initially migrated upward in columella cells of horizontally-oriented roots, after which they moved to the proximal ends of the cells by 15 min after reorientation. No significant pattern of redistribution of vacuoles, mitochondria, dictyosomes, or hyaloplasm was detected that correlated with the onset of gravicurvature. These results indicate that amyloplasts and nuclei are the only organelles whose movements correlate positively with the onset of gravicurvature by primary roots of this cultivar of Zea mays.

  7. Lymnaea viatrix and Lymnaea columella in the neotropical region: a distributional outline

    Directory of Open Access Journals (Sweden)

    W. Lobato Paraense

    1982-06-01

    Full Text Available A review of lymnaeid samples collected by the author from 106 localities in Mexico, Cuba, Jamaica, Haiti, Dominican Republic, Puerto Rico, Martinique, Saint Lucia, Guatemala, Costa Rica, Panamá, Ecuador, Peru, Bolivia, Chile, Argentina, Uruguay andBrazil showed that one of them (from Ecuador belonged to Lymnaea cousini Jousseaume, 1887, and all the others to either L. viatrix Orbigny, 1835 or l. columella Say, 1817. The ranges of L. viatrix and L. columella overlap in Middle America, and in northern and southern South America (Venezuela-Colombia-Ecuador and northeastern Argentina-Uruguay-southernmost Brazil, respectively. L. viatrix was the only species found in Peru west of the Andes and in Chile, and is supposed to have migrated eastward to Argentina via the Negro river basin. The range of L. columella in South America is discontinuous. The species has been recorded from Venezuela, Colombia and Ecuador and, east of the Andes, from latitudes 15º S (central-west Brazil to 35º S (La Plata, Argentina. Such a gap may be attributed to either introduction from the northern into the southern area, or migration along the unsampled region on the eastern side of the Andes, or extinction in the now vacant area. No lymnaeids have been found so far in Brazil north of latitude 15º S and in the Guianas.A revisão de amostras de limneídeos coletados pelo autor em 106 localidades no México, Cuba, Jamaica, Haiti, República Dominicana, Porto Rico, Martinica, Santa Lúcia, Guatemala, Costa Rica, Panamá, Equador, Peru, Bolívia, Chile, Argentina, Uruguai e Brasil mostrou que uma delas (do Equador pertencia a Lymnaea cousini Jousseaume, 1887, e que todas as outras pertenciam a L. viatrix Orbigny, 1835 ou a L. columella Say, 1817. As distribuições da L. viatrix e da l. columella sobrepõem-se na Meso-América e na América do Sul setentrional (Venezuela-Colômbia-Equador e meridional (nordeste da Argentina-Uruguai-extremo sul do Brasil. A L. viatrix foi a

  8. Gravity-regulated differential auxin transport from columella to lateral root cap cells

    Science.gov (United States)

    Ottenschlager, Iris; Wolff, Patricia; Wolverton, Chris; Bhalerao, Rishikesh P.; Sandberg, Goran; Ishikawa, Hideo; Evans, Mike; Palme, Klaus

    2003-01-01

    Gravity-induced root curvature has long been considered to be regulated by differential distribution of the plant hormone auxin. However, the cells establishing these gradients, and the transport mechanisms involved, remain to be identified. Here, we describe a GFP-based auxin biosensor to monitor auxin during Arabidopsis root gravitropism at cellular resolution. We identify elevated auxin levels at the root apex in columella cells, the site of gravity perception, and an asymmetric auxin flux from these cells to the lateral root cap (LRC) and toward the elongation zone after gravistimulation. We differentiate between an efflux-dependent lateral auxin transport from columella to LRC cells, and an efflux- and influx-dependent basipetal transport from the LRC to the elongation zone. We further demonstrate that endogenous gravitropic auxin gradients develop even in the presence of an exogenous source of auxin. Live-cell auxin imaging provides unprecedented insights into gravity-regulated auxin flux at cellular resolution, and strongly suggests that this flux is a prerequisite for root gravitropism.

  9. Lichen Endozoochory by Snails

    Science.gov (United States)

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

    2011-01-01

    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. PMID:21533256

  10. 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.

  11. Stabilization technique for columella using trimmed autologous temporal fascia in type III and IV tympanoplasty--Muffler method.

    Science.gov (United States)

    Kanemaru, Shin-Ichi; Ito, Juichi; Tsuji, Jun; Fujino, Kiyohiro; Hiraumi, Harukazu; Omori, Koichi

    2007-02-01

    High success rates of recovery of hearing level in type III and IV tympanoplasty could be achieved by this stabilization technique for columella using trimmed autologous temporal fascia. The aim of this study was to evaluate a new stabilization technique for columella using trimmed autologous temporal fascia in type III and IV tympanoplasty. A total of 55 patients (21 male, 34 female, aged 4-85 years) with chronic otitis media (n=16) and cholesteatoma (n=39) underwent tympanoplasty using this new stabilization technique for columella. Thirty-one patients underwent type III tympanoplasty and 24 patients underwent type IV tympanoplasty. Forty-two patients underwent a staged operation and 13 patients underwent a single operation. The observation period was 3.5 years from 6 months after the last operation. The overall success rates in type III and IV tympanoplasty were 87.1% (27/31) and 83.3% (20/24), respectively. Two of eight patients for whom the procedure was unsuccessful underwent reoperation and they acquired good hearing.

  12. Statolith Sedimentation Kinetics and Force Transduction to the Cortical Endoplasmic Reticulum in Gravity-Sensing Arabidopsis Columella Cells[W][OA

    Science.gov (United States)

    Leitz, Guenther; Kang, Byung-Ho; Schoenwaelder, Monica E.A.; Staehelin, L. Andrew

    2009-01-01

    The starch statolith hypothesis of gravity sensing in plants postulates that the sedimentation of statoliths in specialized statocytes (columella cells) provides the means for converting the gravitational potential energy into a biochemical signal. We have analyzed the sedimentation kinetics of statoliths in the central S2 columella cells of Arabidopsis thaliana. The statoliths can form compact aggregates with gap sizes between statoliths approaching <30 nm. Significant intra-aggregate sliding motions of individual statoliths suggest a contribution of hydrodynamic forces to the motion of statoliths. The reorientation of the columella cells accelerates the statoliths toward the central cytoplasm within <1 s of reorientation. During the subsequent sedimentation phase, the statoliths tend to move at a distance to the cortical endoplasmic reticulum (ER) boundary and interact only transiently with the ER. Statoliths moved by laser tweezers against the ER boundary experience an elastic lift force upon release from the optical trap. High-resolution electron tomography analysis of statolith-to-ER contact sites indicate that the weight of statoliths is sufficient to locally deform the ER membranes that can potentially activate mechanosensitive ion channels. We suggest that in root columella cells, the transduction of the kinetic energy of sedimenting statoliths into a biochemical signal involves a combination of statolith-driven motion of the cytosol, statolith-induced deformation of the ER membranes, and a rapid release of kinetic energy from the ER during reorientation to activate mechanosensitive sites within the central columella cells. PMID:19276442

  13. Optimal stocking densities of snails [ Archachatina marginata ...

    African Journals Online (AJOL)

    5 snails per cage was uneconomic. 6 to 12 snails per cage (22 to 44 snails per m2) was recommended as the optimal stocking density of breeding snails of A.m.s. Experiment II had 2, 3, 4, 5 and 6 A.m.s. fattening snails per cage of 20cm x 20cm.Treatments I to III with mean daily weight gains of 3.3g, 2.6g and 3.0g mean ...

  14. 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

  15. 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.

  16. 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

  17. SHORT COMMUNICATION Challenges to increased Snail ...

    African Journals Online (AJOL)

    Snails for human consumption in numerous forms are from the people who raise or gather them from nearby bushes and sell them along road sides or in the local market. The commercial production of snails has not kept pace with the demand for it in Ibarapa Local Government Areas (ILGA) of Oyo State, Nigeria. A study ...

  18. Current Situation of Edible Snails in Indonesia

    Directory of Open Access Journals (Sweden)

    Schneider, K.

    1999-01-01

    Full Text Available From March 7, 1995 to April 16, 1995 du ring the rainy season the utilisation of edible snails was investigated in Indonesia. To assess the current situation, the focus was put to answer the following questions : - Is it feasible under the present circumstances to domesticate these snails with the aim to conserve the natural resources ? - Could any individual or private initiative be enhanced or utilized ? - Would local disadvantaged groups (traditional animal farmers, women oryouths be benefitted through domestication of these snails ? - Is there any existing private organisation or NGO, which already gathers and trades the snails or would be interested to do this in the future ? Snails gatherers, -dealers and -farmers were visited and interviewed on the following topics using standardised questionnaires : Spreading and ecology ways of marketing, consumption habits, breeding and rearing. Diotopes were also visited and investigated. Results Spreading and ecology : Achatina fulica, Pomacea canaliculata, Pila ampullacea and Bellamia javanica are eaten. The snails can be found ail overJava. Ways of marketing : The snails gathered in the biotope are either marketed directly or through various marketing paths. A. fulica is exported in large quantifies. The population is therefore endangered. Consumption habits : Snails are not eaten regularly. Snail meat is known to be healthy. The consumption depends on the consumer's ethnie background. Breeding and rearing experience : with simple breeding systems for A. fulica and P. canaliculata are seldom found. The breeding of P. canaliculata is forbidden in Indonesia. There is no interest in breeding P. ampullacea or B. javanica. The breeding of A. fulica can ben-efit disadvantaged groups financially and help to conserving the natural snail population.

  19. Public Health Implications of Aquatic Snails around Fish Ponds in ...

    African Journals Online (AJOL)

    A survey of aquatic snails around fish ponds in Okwe, Delta State was conducted to identify snails and their public health implications in the area. Snails were collected fortnightly within an hour of active snail search for a period of twelve months from randomly selected eight fish ponds using a scoop net attached to a long ...

  20. Seasonal dynamics of snail populations in coastal Kenya: Model calibration and snail control

    Science.gov (United States)

    Gurarie, D.; King, C. H.; Yoon, N.; Wang, X.; Alsallaq, R.

    2017-10-01

    A proper snail population model is important for accurately predicting Schistosoma transmission. Field data shows that the overall snail population and that of shedding snails have a strong pattern of seasonal variation. Because human hosts are infected by the cercariae released from shedding snails, the abundance of the snail population sets ultimate limits on human infection. For developing a predictive dynamic model of schistosome infection and control strategies we need realistic snail population dynamics. Here we propose two such models based on underlying environmental factors and snail population biology. The models consist of two-stage (young-adult) populations with resource-dependent reproduction, survival, maturation. The key input in the system is seasonal rainfall which creates snail habitats and resources (small vegetation). The models were tested, calibrated and validated using dataset collected in Msambweni (coastal Kenya). Seasonal rainfall in Msambweni is highly variable with intermittent wet - dry seasons. Typical snail patterns follow precipitation peaks with 2-4-month time-lag. Our models are able to reproduce such seasonal variability over extended period of time (3-year study). We applied them to explore the optimal seasonal timing for implementing snail control.

  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 (population...

  2. 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...

  3. 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...

  4. Schistosomes and snails: a molecular encounter

    Directory of Open Access Journals (Sweden)

    Matty eKnight

    2014-07-01

    Full Text Available Biomphalaria glabrata snails play an integral role in the transmission of Schistosoma mansoni, the causative agent for human schistosomiasis in the Western hemisphere. For the past two decades, tremendous advances have been made in research aimed at elucidating the molecular basis of the snail/parasite interaction. The growing concern that there is no vaccine to prevent schistosomiasis and only one effective drug in existence provides the impetus to develop new control strategies based on eliminating schistosomes at the snail-stage of the life cycle. To elucidate why a given snail is not always compatible to each and every schistosome it encounters, B. glabrata that are either resistant or susceptible to a given strain of S. mansoni have been employed to track molecular mechanisms governing the snail/schistosome relationship. With such snails, genetic markers for resistance and susceptibility were identified. Additionally, differential gene expression studies have led to the identification of genes that underlie these phenotypes. Lately, the role of schistosomes in mediating non-random relocation of gene loci has been identified for the first time, making B. glabrata a model organism where chromatin regulation by changes in nuclear architechture, known as spatial epigenetics, orchestrated by a major human parasite can now be investigated. This review will highlight the progress that has been made in using molecular approaches to describe snail/schistosome compatibility issues. Uncovering the signaling networks triggered by schistosomes that provide the impulse to turn genes on and off in the snail host, thereby controlling the outcome of infection, could also yield new insights into anti-parasite mechanism(s that operate in the human host as well.

  5. Growth, Age Determination and Longevity in the Giant African Snail ...

    African Journals Online (AJOL)

    Growth, Age Determination and Longevity in the Giant African Snail Archachatina marginata (Swainson) ... The implication of this studies for snail culture is that, in semi-intensive systems with minimal input, giant snails can be kept up to 11/2 years for them to reach competitive market sizes. Key Words: Archachatina ...

  6. Characteristics of snail farmers and constraints to increased ...

    African Journals Online (AJOL)

    Administrator

    impediment to increased snail supply. All farmers interviewed in Ghana reported feeding of snails to be less of a problem, as the giant snail which they rear is essentially vegetarian and browses on a wide range of leaves. In Cameroon, farmers complained of slow growth rates using local diets. Of all the farmers interviewed,.

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

    African Journals Online (AJOL)

    SARAH

    2014-12-01

    Dec 1, 2014 ... markets of Abidjan (Côte d'Ivoire). 7633 this activity, often, since adolescence with aunts with whom they have been learning snail trade. To reach the final consumer, the snail go through the collectors, wholesalers and retailers. The general scheme of marketing snail is almost the same as those of rattan.

  8. Profitability of Snail Production in Osun State,Nigeria | Baba ...

    African Journals Online (AJOL)

    The costs and returns analysis revealed that variable costs accounted for 96% of the production costs. Labour was the most costly single item in snail production in the area. The results further showed that snail farming was highly profitable, with the average farmer earning a net return of 40 naira per snail. There was a profit ...

  9. Occurrence of digenean larvae in freshwater snails in the Ruvu ...

    African Journals Online (AJOL)

    Occurrence of digenean larvae in freshwater snails in the Ruvu basin, Tanzania. G Nkwengulila, ESP Kigadye. Abstract. A survey was carried out on digenean larvae infecting freshwater snails in five habitats in Dar es Salaam, Ruvu and Morogoro. 9424 snails belonging to 12 species from five families were examined for ...

  10. Growth performance of African Giant Land Snails (Archachatina ...

    African Journals Online (AJOL)

    This experiment was set up to assess the sensory evaluation of African giant land snails (Archachatina marginata) fed dried kola nut testa (DKT) and palm kernel cake mixture (PKC). A total of 72 snails were randomly distributed into four (4) dietary treatments which were replicated 3 times with 6 snails per replicate in a ...

  11. Characteristics of snail farmers and constraints to increased ...

    African Journals Online (AJOL)

    A study was carried out to characterize snail farmers, identify constraints to increased snail production and suggest strategies required to conserve edible snail species and sustain livelihoods. Structured questionnaires and focus group discussions were used for data collection in selected locations in Cameroon and Ghana.

  12. Effects of artificially induced aestivation on edible tropical land snail ...

    African Journals Online (AJOL)

    The effects of artificially induced aestivation on edible tropical land snail species Achatina achatina under controlled laboratory conditions for 12 weeks in plastic snaileries was studied, comparing active (control) snails given water and food ad libitum with aestivated snails without food and water. Parameters determined ...

  13. the occurrence of digenean larvae in freshwater snails at mbezi ...

    African Journals Online (AJOL)

    numbers and distribution (spatial and temporal) of snail hosts. Snails could be flushed out of their habitats, thus, affecting prevalence of digenean larvae (see. Jordan et al. 1980). Snail habitats could be obliterated by floods and increased velocity of water current might sweep away the infective stages (miracidia). 61 ...

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

    Directory of Open Access Journals (Sweden)

    Jiun-Jye Wang

    2011-05-01

    Full Text Available 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.

  15. 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...... 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...

  16. Modeling snail breeding in a bioregenerative life support system

    Science.gov (United States)

    Kovalev, V. S.; Manukovsky, N. S.; Tikhomirov, A. A.; Kolmakova, A. A.

    2015-07-01

    The discrete-time model of snail breeding consists of two sequentially linked submodels: "Stoichiometry" and "Population". In both submodels, a snail population is split up into twelve age groups within one year of age. The first submodel is used to simulate the metabolism of a single snail in each age group via the stoichiometric equation; the second submodel is used to optimize the age structure and the size of the snail population. Daily intake of snail meat by crewmen is a guideline which specifies the population productivity. The mass exchange of the snail unit inhabited by land snails of Achatina fulica is given as an outcome of step-by-step modeling. All simulations are performed using Solver Add-In of Excel 2007.

  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. 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.

  19. 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...

  20. Learning from a Sea Snail: Eric Kandel

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 6. Learning from a Sea Snail: Eric Kandel. Rohini Balakrishnan. Research News Volume 6 Issue 6 June 2001 pp 86-90. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/006/06/0086-0090 ...

  1. BHC80 is Critical in Suppression of Snail-LSD1 Interaction and Breast Cancer Metastasis

    Science.gov (United States)

    2014-04-01

    LSD1 were amplified from HeLa cDNA and respectively cloned into pCMV- Tag2B with an N-terminal Flag tag. Snail mutant was generated using the...QSRKAFNCKYC Snail (Canine) QTRKAFNCKYC Snail ( Monkey ) QSRKAFNCKYC Snail (Opossum) QPRKAFICKVC A D E F CHX 0 1 3 5 7 0 1 3 5 7 WT Snail

  2. Parasites of edible land snails in Edo State, Nigeria

    Directory of Open Access Journals (Sweden)

    Igbinosa I. B.

    2016-12-01

    Full Text Available Land snails are sources of protein to man and are hosts to a number of parasites. It is imperative that the roles of the snail hosts and parasites are clearly defined. Before then however, the parasites of the different land snails collected in any locality should be identified. Land snails were collected in the wild in both dry and wet seasons. The internal organs and the faeces were examined for the presence of parasite. In the rainy season of 2015, a total of 272 snails were collected across four major towns (Benin, Uromi, Ekpoma and Auchi in Edo State, Nigeria, while in the dry season, fewer snails (n=91 were handpicked. The snail species seen are: Achatina achatina (Linnaeus, 1758, Achatina fulica (Férussac, 1821, Acharchatina marginata (Swainson, 1982, Limicolaria aurora (Jay, 1839, L. flammea (Müller, 1774 and Limicolariopsis spp. The larvae of Strongyloides stercoralis were isolated from the various snail species with overall prevalence of 54.04 %. Snails positive with Alaria mesocercariae were L. aurora, L. flammea and Limicolariopsis spp. Additionally, few L. flammea were positive of the cercariae of Drocoelium dedriticum. Meanwhile, some samples of A. fulica harboured larvae of Angiostrongylus cantonesis, sporocysts of Fasciola gigantica and Schistosoma mansoni. Therefore, these edible snails could pose serious health hazard to man and animals by serving as a possible alternative parasite transmission route.

  3. 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.

  4. 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.

  5. Crawling beneath the free surface: Water snail locomotion

    OpenAIRE

    Lee, Sungyon; Bush, John W. M.; 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 g...

  6. 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.

  7. 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.

  8. Nutritive potentials and utilization of garden snail (Limicolaria aurora ...

    African Journals Online (AJOL)

    The possibility of using garden snail (Limicolaria aurora) meat meal as a protein source in fish feeds was tested in Clarias gariepinus fingerlings. Five isonitrogenous (43% crude protein) diets in which garden snail meat meal was used to replace fish meal at 0%, (control diet), 25, 50, 75 and 100% inclusion levels were used ...

  9. Effects of feeding adult snails Stylosanthes guianensis or Lablab ...

    African Journals Online (AJOL)

    The feeding trial assessed the performance, carcass and sensory evaluation of adult snails fed solely on leaves of Stylosanthes guianensis or Lablab purpureus as substitute for pawpaw leaf. Ninety-six (96) adult snails were used for the trial, and they were shared into three groups. Each group was replicated four times with ...

  10. The role of snail aestivation in transmission of schistosomiasis in ...

    African Journals Online (AJOL)

    This review assesses the possible impacts of climate change on the temporal and spatial distribution of schistosomiasis-transmitting snails with special emphasis on aestivation, and discusses the effect of schistosome infection on aestivation ability. The impacts of parasite development on snails, as well as physiological ...

  11. Nutritive potentials and utilization of garden snail (Limicolaria aurora ...

    African Journals Online (AJOL)

    AJB SERVER

    2006-10-16

    Oct 16, 2006 ... The possibility of using garden snail (Limicolaria aurora) meat meal as a protein source in fish feeds was tested in ... garden snail meat meal was used to replace fish meal at 0%, (control diet), 25, 50, 75 and 100% inclusion levels ..... in a diet could provide the essential amino acid requirement of the fish ...

  12. 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…

  13. Biochemical evaluation of aestivation and starvation in two snail ...

    African Journals Online (AJOL)

    The agents transmitting this disease are the Bulinus snails which employ aestivation to survive conditions of unfavourable weather such as lack of food and water. The mechanism ... All the snails were fed on lettuce ad libitum for 28 days during which water was completely drained out in the aestivation slope. The aestivation ...

  14. 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

  15. Oxygen consumption and responses of the freshwater snail Bulinus ...

    African Journals Online (AJOL)

    replenish the air bubble in the mantle cavity, if necessary. The total duration of the experiment per snail was eight hours: 30 minutes gas mixture water equilibration, 30 minutes for thermo-barometric stabilization and one hour measurement at a particular oxygen tension. It means that each snail was exposed for one hour to ...

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

    African Journals Online (AJOL)

    The socio-economic characteristic of snail farmers in Oyo State Agricultural Development Programme (ADP) was evaluated in two out of the four zones that were available. The two zones selected were Ibadan/Ibarapa and Oyo zones, to determine the factors related to snail production, consumption and marketing in the ...

  17. CYTOGENETIC STUDY OF FOUR SPECIES OF LAND SNAILS OF ...

    African Journals Online (AJOL)

    (O.F.Muller, 1774) ( Bivalvia: Veneroidea: Corbiculidae) : Taxonomic status. Assessment of a frteshwater clam. Folia biologica(Krakow) 57:3-4. Solem, A. 1984. A world model of land snail diversity and abundance, in Solem, A., van. Bruggen, A.C.(eds), World-wide snails: biogeographical studies on non-marine Mollusca.

  18. Haemolymph Biochemical Parameters of the African Giant Snail ...

    African Journals Online (AJOL)

    A comparative analysis of the biochemical profiles of the haemolymph of 50 each of apparently normal captive African giant snail, (Achatina achatina) and the big black snail, (Achachatina marginata) was carried out. The mean protein (total protein, albumin, globulin and albumin:globulin ratio) levels, excretory products ...

  19. Nutritional Assessment of Some Nigerian Land and Water Snail ...

    African Journals Online (AJOL)

    Choice-Academy

    rapidly increasing human population. The food deficit situation is more intense with protein deficiency ... research to commercial snail resource farming which could additionally generate revenue to augment the ... demands, commercial snail farming as could be found in Europe, South East Asia and the. United States of ...

  20. Proximate and chemical composition of three species of snails in ...

    African Journals Online (AJOL)

    This trial was conducted to determine the proximate and chemical composition of three common species of snails in Nigeria. The species were Archachatina marginata (T1), Achatina achatina (T2), and Achatina fulica (T3). The three species constituted the three treatments and thirty-six adult snails were used for this trial ...

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

    African Journals Online (AJOL)

    Objective: this study aimed to estimate the amount of snail's shells produced in the Abidjan City and the mode of management of empty shells for possible reuse. Methodology and Results: An investigation was carried out by a questionnaire on 120 snail retailers' in the markets of Abidjan. The data was stripped by Sphinx ...

  2. Ecology and distribution of gastropod snails of medical and ...

    African Journals Online (AJOL)

    Ecology and distribution of gastropod snails of medical and veterinary importance in Municipal Area Council, FCT, Abuja. ... of the snails which are intermediate hosts of medical/ veterinary importance under suitable physicochemical parameters which determines the extent of their population and distribution in the area.

  3. Dispersion factors in the arboreal snail Sitala jenynsi (Gastropoda ...

    African Journals Online (AJOL)

    Sitala jenynsi snails from the University and Wazo populations of Dar es Salaam, Tanzania, were released on grass, and on forest terrain, in both regions during the dry (February, March) and the rainy seasons (April). Snail dispersion was assessed as weekly quadratic means and as the overall Diffusion Coefficient 0.423 ...

  4. 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 scale. The results show that only 23.90% of the respondents are females while about 74% of the respondents had herd size of less than 1000 snails. Snail farmers with tertiary education are more in the distribution (44.10%) while civil ...

  5. 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...

  6. 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.

  7. 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.

  8. 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

  9. Land Snail Extinctions at Kalaeloa, O`ahu

    Directory of Open Access Journals (Sweden)

    T.S. Dye

    2001-06-01

    Full Text Available In this article we show that the interpretation of Polynesian influence drawn from the stratigraphic record of sub-fossil land snails at Kalaeloa (O'ahu, Hawai'i is based on a unique stratigraphic sequence at a single sinkhole. The interpretation was then applied to other land snail sequences, despite their lack of evidence for Polynesian influence. We present a reanalysis of the stratigraphic record to conclude that Polynesians had little, if any, effect on land snail populations in sinkholes. We show that directional change in land snail populations was underway before Polynesians colonised the islands. Decreases in the diversity of snail populations, possibly indicative of environmental stress, do occur near the end of the stratigraphic sequence. Based on available dating evidence, however, these changes probably took place in the post-Contact period when the regional environment was radically altered by sugar cane cultivation.

  10. SPATIAL DISTRIBUTION OF LYMNAEIDAE (MOLLUSCA, BASOMMATOPHORA), INTERMEDIATE HOST OF Fasciola hepatica LINNAEUS, 1758 (TREMATODA, DIGENEA) IN BRAZIL

    Science.gov (United States)

    Medeiros, Camilla; Scholte, Ronaldo Guilherme Carvalho; D'ávila, Sthefane; Caldeira, Roberta Lima; Carvalho, Omar dos Santos

    2014-01-01

    Snails of the family Lymnaeidae act as intermediate hosts in the biological cycle of Fasciola hepatica, which is a biological agent of fasciolosis, a parasitic disease of medical importance for humans and animals. The present work aimed to update and map the spatial distribution of the intermediate host snails of F. hepatica in Brazil. Data on the distribution of lymnaeids species were compiled from the Collection of Medical Malacology (Fiocruz-CMM, CPqRR), Collection of Malacology (MZUSP), “SpeciesLink” (CRIA) network and through systematic surveys in the literature. Our maps of the distribution of lymnaeids show that Pseudosuccinea columella is the most common species and it is widespread in the South and Southeast with few records in the Midwest, North and Northeast regions. The distribution of the Galba viatrix, G. cubensis and G. truncatula showed a few records in the South and Southeast regions, they were not reported for the Midwest, North and Northeast. In addition, in the South region there are a few records for G. viatrix and one occurrence of Lymnaea rupestris. Our findings resulted in the first map of the spatial distribution of Lymnaeidae species in Brazil which might be useful to better understand the fasciolosis distribution and delineate priority areas for control interventions. PMID:24879003

  11. 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

    National Research Council Canada - National Science Library

    Awah, AA; Obehi Edeoghon, C; Lalabe, BC; Omo-Erigbe, P

    2001-01-01

    ...) 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...

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

    Science.gov (United States)

    Clausen, Jesper Hedegaard; Madsen, Henry; Murrell, K Darwin; Phan Thi, Van; Nguyen Manh, Hung; Viet, Khue Nguyen; Dalsgaard, Anders

    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 to juvenile fish raised in carp nurseries. Snail population density and prevalence of trematode (Heterophyidae) infections were determined in 48 carp nurseries producing Rohu juveniles, (Labeo rohita) in the Red River Delta area. Fish samples were examined at 3, 6 and 9 weeks after the juvenile fish were introduced into the ponds. There was a significant positive correlation between prevalence of FZT metacercariae in juvenile fish and density of infected snails. Thus, the odds of infection in juvenile fish were 4.36 and 11.32 times higher for ponds with medium and high density of snails, respectively, compared to ponds where no infected snails were found. Further, the intensity of fish FZT infections increased with the density of infected snails. Interestingly, however, some ponds with no or few infected snails were collected also had high prevalence and intensity of FZT in juvenile fish. This may be due to immigration of cercariae into the pond from external water sources. The total number and density of potential host snails and density of host snails infected with heterophyid trematodes in the aquaculture pond is a useful predictor for infections in juvenile fish, although infection levels in juvenile fish can occur despite low density or absence infected snails. This suggests that intervention programs to control FZT infection of fish should include not only intra

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

    Directory of Open Access Journals (Sweden)

    Jesper Hedegaard Clausen

    Full Text Available BACKGROUND: 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 to juvenile fish raised in carp nurseries. METHODOLOGY/PRINCIPAL FINDINGS: Snail population density and prevalence of trematode (Heterophyidae infections were determined in 48 carp nurseries producing Rohu juveniles, (Labeo rohita in the Red River Delta area. Fish samples were examined at 3, 6 and 9 weeks after the juvenile fish were introduced into the ponds. There was a significant positive correlation between prevalence of FZT metacercariae in juvenile fish and density of infected snails. Thus, the odds of infection in juvenile fish were 4.36 and 11.32 times higher for ponds with medium and high density of snails, respectively, compared to ponds where no infected snails were found. Further, the intensity of fish FZT infections increased with the density of infected snails. Interestingly, however, some ponds with no or few infected snails were collected also had high prevalence and intensity of FZT in juvenile fish. This may be due to immigration of cercariae into the pond from external water sources. CONCLUSIONS/SIGNIFICANCE: The total number and density of potential host snails and density of host snails infected with heterophyid trematodes in the aquaculture pond is a useful predictor for infections in juvenile fish, although infection levels in juvenile fish can occur despite low density or absence infected snails. This suggests that

  14. A survey of snail farms in Cross River State, Nigeria | Ogogo | Global ...

    African Journals Online (AJOL)

    The existence of snail in the wild has become threatened, and information on the efficiency and effectiveness of ex - situ management of snails in many areas is urgently needed for consistent supply of snails. This work, therefore surveyed the practice and adoption of snail farming technology in Cross River State, Nigeria.

  15. 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

  16. 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

    OpenAIRE

    Awah, AA.; Obehi Edeoghon, C.; Lalabe, BC.; Omo-Erigbe, P.

    2001-01-01

    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...

  17. Interactions between freshwater snails and tadpoles: competition and facilitation.

    Science.gov (United States)

    Brönmark, Christer; Rundle, Simon D; Erlandsson, Ann

    1991-06-01

    Freshwater snails and anuran tadpoles have been suggested to have their highest population densities in ponds of intermediate size where abiotic disturbance (e.g. desiccation) is low and large predators absent. Both snails and tadpoles feed on periphytic algae and, thus, there should be a large potential for competitive interactions to occur between these two distantly related taxa. In a field experiment we examined the relative strength of competition between two closely related snail species, Lymnaea stagnalis and L. peregra, and between L. stagnalis and tadpoles of the common frog, Rana temporaria. Snail growth and egg production and tadpole size at and time to metamorphosis were determined. Effects on the common food source, periphyton, were monitored with the aid of artificial substrates. Periphyton dry weight was dramatically reduced in the presence of snails and/or tadpoles. There were no competitive effects on growth or egg production of the two snail species when they were coexisting. Mortality of L. peregra was high (95%) after reproduction, but independent of treatment. Growth of L. stagnalis was reduced only at the highest tadpole densities, whereas egg production was reduced both by intraspecific competition and by competition with tadpoles. Differences in egg production were retained after tadpole metamorphosis. Tadpole larval period increased, weight of metamorphosing frogs decreased and growth rate was reduced as a function of increasing tadpole density. However, contrary to expectation, snails had a positive effect on tadpole larval period, weight and growth rate. Further, in experimental containers without snails there was a dense growth of the filamentous green alga Cladophora sp. We suggest that the facilitative effects of snails on tadpoles are due to an "indirect mutualistic" mechanism, involving competition between food sources of different quality (microalgae and Cladophora sp.) and tadpoles being competitively dominant over snails for the

  18. [Simulation experiment of survival and reproduction of artificially imported Oncomelania snails in Qingpu District, Shanghai].

    Science.gov (United States)

    Tian, Jian-Guo; Li, Gui-Fu; Li, Jun; Zhang, Xiao-Ping; Jin, Yan-Jun; Cai, Li; Peng, Li-Xia; Xu, Hai-Yan; Xu, Rui-Fang

    2013-06-01

    To understand the survival of imported Oncomelania snails in new environments with different densities in waterway net region, Qingpu District, Shanghai. The snails collected from Guichi, Anhui Province were put into the ponds of 4 square meters and each had 25, 50, 100, 200, 400 and 800 pairs of snails, respectively. During the next 2 years, the temperature, humidity, the activities of snails and their second birth snails were investigated each day. All the data were analyzed statistically. The highest number of snails appeared from May to June on the surface of soils in different densities. The average numbers of snails were 2.0%-12.7% of whole put in snails, and the numbers of offspring were less than 2% of the whole put in snails. The survival and reproduction of artificially imported Oncomelania snails from Guichi, Anhui Province is not good in Qingpu District, Shanghai.

  19. [Establishment of Oncomelania hupensis snail database based on smartphone and Google Earth].

    Science.gov (United States)

    Wang, Wei-chun; Zhan, Ti; Zhu, Ying-fu

    2015-02-01

    To establish an Oncomelania hupensis snail database based on smartphone and Google Earth. The HEAD GPS software was loaded in the smartphone first. The GPS data of the snails were collected by the smartphone. The original data were exported to the computer with the format of KMIUKMZ. Then the data were converted into Excel file format by using some software. Finally, the results based on laboratory were filled, and the digital snail data were established. The data were converted into KML, and then were showed by Google Earth visually. The snail data of a 5 hm2-beach along the Yangtze River were collected and the distribution of the snails based on Google Earth was obtained. The database of the snails was built. The query function was implemented about the number of the total snails, the living snails and the schistosome infected snails of each survey frame. The digital management of the snail data is realized by using the smartphone and Google Earth.

  20. 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.

  1. Transfer of lead by freshwater snails in Ullswater, Cumbria

    Energy Technology Data Exchange (ETDEWEB)

    Everard, M.; Denny, P.

    1984-01-01

    The cycling of lead by freshwater snails from primary producers and detritus, through the snails and snail-predators, and back into the sediment was investigated. The concentrations of lead in snails collected from Ullswater, Cumbria, correlated with the degree of contamination at particular sites. When snails were fed on lead-enriched food in the laboratory, their digestive glands, feet and shells all accumulated the metal to some extent. It was not distributed equally among the tissues of Lymnaea peregra; the foot and digestive gland normally contained 2 to 4 and 3 to 10 times more lead than the shell, respectively. It appears that lead is laid down inexchangeably in the structural material of the shell while in soft tissues lead-containing granules are induced. These may be relocated and excreted and, when snails are transferred to lead-free conditions, their total lead content falls back to near-background levels. In Ullswater, contaminated snails, containing up to 5.6 mg Pb/g dry weight, are grazed by eels almost exclusively for some periods of the year but the majority of lead ingested by the fish passes straight through the gut. 17 references, 5 figures, 1 table.

  2. The Helix aspersa (brown garden snail) allergen repertoire.

    Science.gov (United States)

    Martins, Luís Miguel Lourenço; Peltre, Gabriel; da Costa Faro, Carlos José Fialho; Pires, Euclides Manuel Vieira; da Cruz Inácio, Filipe Fernando

    2005-01-01

    Ingestion of snails can induce strong asthmatic or anaphylactic responses, mainly in house-dust-mite-sensitized patients. The aim of this study was to identify the Helix aspersa (Hel a), Theba pisana (The p) and Otala lactea (Ota l) allergens and the extent of their cross-reactivity with the Dermatophagoides pteronyssinus (Der p) mite. In 60 atopic patients, skin prick tests (SPT) to snail and D. pteronyssinus, total and specific IgE, specific IgE immunoblots, RAST and immunoblot inhibition assays were performed. Mean total IgE was >1,000 kU/l. Mean specific IgE (class 6 for Der p and class 2 for Hel a) SPT were positive in 44 patients for snail and in 56 for mite. Isoelectric focusing (IEF) and SDS-PAGE followed by immunoblotting of H. aspersa extract enabled the identification of 27 and 20 allergens, respectively. Myosin heavy chains from snails (molecular weight >208 kDa) disclosed two major allergens. Hel a and Der p RAST were strongly inhibited by their homologous extracts, with Hel a RAST being inhibited by the Der p extract to a much greater extent (72.6%) than the inverse (5.6%). A complete inhibition of the immunoblots by their homologous extract was obtained. However, Hel a extract did not inhibit Der p IEF separated recognition. On the other hand, mite extract extensively inhibited snail immunoblots from both IEF and SDS-PAGE separations. Immune detection on chicken, pig, rabbit, cow and horse myosins did not reveal any IgE cross recognition with snail. In most cases of snail allergy, mite appeared to be the sensitizing agent. Nevertheless, snails may also be able to induce sensitization by themselves. This hypothesis is supported by the finding of specific IgE to Hel a in 2 patients who did not show specific IgE to Der p, and one of them was suffering from asthma after snail ingestion.

  3. 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.

  4. 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

  5. Chemical mediation of egg capsule deposition by mud snails.

    Science.gov (United States)

    Rittschof, Dan; Sawardecker, Prasad; Petry, Caroline

    2002-11-01

    Mud snails (Ilyanassa obsoleta = Nassarius obsoletus = Nassa obsoleta) deposit eggs in protective capsules on hard substrata in soft bottom environments. We studied sites of egg capsule deposition and snail movement responses to odors to determine if chemoreception plays a role in deposition site selection. From results of field surveys, laboratory experiments, and field experiments, we conclude that mud snails use chemoreception for capsule deposition. Attractive odors originate from mud snail and whelk egg capsules and from living bivalves. Evidence for attractive odors from conspecifics is equivocal. Capsules are deposited on living odor sources and nearby hard substrates. We hypothesize that deposition of capsules on living substrates increases the likelihood that embryos will survive by decreasing the chance of smothering of embryos by sediments.

  6. Comparative Studies of two Fresh Water Snail Distributions and ...

    African Journals Online (AJOL)

    chemical properties of fresh water on snail hosts population. The methods in Water Engineering and Development Centre (WEDC) Analytical methods Manual were used in water analysis. Fresh water bodies namely: Kanye and Rimin Gado Dams ...

  7. 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...

  8. Differences in predatory pressure on terrestrial snails by birds and ...

    Indian Academy of Sciences (India)

    by birds and mammals. ZUZANNA M ROSIN( PAULINA OLBORSKA( ADRIAN SURMACKI AND PIOTR TRYJANOWSKI. Supplementary table 1. Number of analysed individuals of particular species with specification of undamaged and damaged snails. Species. Total number of individuals. Undamaged individuals.

  9. Predation of schistosomiasis vector snails by ostracoda (crustacea)

    Science.gov (United States)

    Sohn, I.G.; Kornicker, L.S.

    1972-01-01

    An ostracod species of Cypretta is an effective predator in laboratory experiments on 1- to 3-day-old Biomphalaria glabrata, a vector snail of the blood fluke that causes the tropical and subtropical disease schistosomiasis.

  10. 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.

  11. [Monitoring report of Oncomelania hupensis snails in Huizhou District in 2013].

    Science.gov (United States)

    Ling, Zhi-li; Hu, Zao-yuan; Fang, Yi-min

    2014-06-01

    To further master the Oncomelania hupensis snail situation in Huizhou District, so as to provide the evidence for improving the prevention and control work. According to the prevalence of schistosomiasis in history and the characteristics of residual snail points in recent years, the snail surveys were carried out with the environmental sampling and systematic sampling method in history snail environments and their surrounding suspicious environments. Totally 5,298,940 m2 in 12 administrative villages of 3 townships were investigated and there were 24 406 m2 snail areas at 5 remaining snail spots in 4 administrative villages. The highest snail density was 283 snails/0.1 m2, and the average density of living snails was 2.31 snails/0.1 m2. A total of 4,303 snails were captured, 1,534 were checked by microscopy, and no infected snails were found. The snail situation is still not stable in Huizhou District, and the monitoring of snail situation still need to be strengthened.

  12. Preparation and evaluation of appertized from snail helix aspersa m

    OpenAIRE

    Loyola López, Nelson Eduardo; Moraga Recabal, Gladys; Acuña Carrasco, Carlos

    2014-01-01

    This study includes the development and evaluation of snails (Helix aspersa M.) appertized, collected at a heliciculture breeding center, located in Los Niches sector, Curico, Maule region, South-central of Chile. The test was conducted at the Laboratory of Sciences of the Catholic University of Maule, Nuestra Señora del Carmen Campus, Curico. The main objective of this work was to study the influence of appertized on sensory attributes and commercial durability of snail Helix aspersa M. A...

  13. Preparation and evaluation of appertized from snail Helix aspersa M

    OpenAIRE

    Nelson Loyola López; Gladys Moraga Recabal; Carlos Acuña Carrasco

    2015-01-01

    This study includes the development and evaluation of snails (Helix aspersa M.) appertized, collected at a heliciculture breeding center, located in Los Niches sector, Curico, Maule region, South-central of Chile. The test was conducted at the Laboratory of Sciences of the Catholic University of Maule, Nuestra Señora del Carmen Campus, Curico. The main objective of this work was to study the influence of appertized on sensory attributes and commercial durability of snail Helix aspersa M. Addi...

  14. Toxicity appraisement of methaldehyde, ferricol®, snail repellent ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-19

    Oct 19, 2009 ... LSD and Tukay-Test among the above treatments has shown that repellent band and methaldehyde with 5 ± 1.3 and 10.6 ± 0.9 percentage of the alive snail on trees, respectively, were more effective than repellent color and biological toxin with 14.2 ± 2.6 and 31.3 ± 3.9 percentage alive snail on citrus trees ...

  15. 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.

  16. Modulation of defensive reflex conditioning in snails by serotonin

    Science.gov (United States)

    Andrianov, Vyatcheslav V.; Bogodvid, Tatiana K.; Deryabina, Irina B.; Golovchenko, Aleksandra N.; Muranova, Lyudmila N.; Tagirova, Roza R.; Vinarskaya, Aliya K.; Gainutdinov, Khalil L.

    2015-01-01

    Highlights Daily injection of serotonin before a training session accelerated defensive reflex conditioning in snails.Daily injection of 5-hydroxytryptophan before a training session in snails with a deficiency of serotonin induced by the “neurotoxic” analog of serotonin 5,7-dihydroxytryptamine, restored the ability of snails to learn.After injection of the “neurotoxic” analogs of serotonin 5,6- and 5,7-dihydroxytryptamine as well as serotonin, depolarization of the membrane and decrease of the threshold potential of premotor interneurons was observed. We studied the role of serotonin in the mechanisms of learning in terrestrial snails. To produce a serotonin deficit, the “neurotoxic” analogs 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 2 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. PMID:26557063

  17. Differential expression of Snail1 transcription factor and Snail1-related genes in alveolar and embryonal rhabdomyosarcoma subtypes

    Directory of Open Access Journals (Sweden)

    Miroslawa Püsküllüoglu

    2010-04-01

    Full Text Available Rhabdomyosarcoma (RMS represents the most common sarcoma of soft tissue among children. Two main RMSsubtypes are alveolar (ARMS and embryonal (ERMS. The major goal of this study was to find differentially expressedgenes between RMS subtypes that could explain higher metastatic potential in ARMS and would be useful for the differentialdiagnosis. Using RQ-PCR analysis we compared expression of Snail1 and Snail-related genes among 7 ARMS and 8ERMS patients' samples obtained from the primary tumors and among 2 alveolar and 2 embryonal cell lines. Our resultsshow that Snail1 is highly expressed both in ARMS patients' samples and the alveolar cell lines. We also found that theexpression of E-Cadherin was downregulated and the expression of Matrix Metalloproteinases 2 and 9 (MMP-2 and MMP-9 was upregulated in ARMS. We assume that, as in many tumors, also in RMS Snail1 acts as a regulator for pathwaysknown for their role in cells' metastasis and that Snail1 activity results in increased MMPs and decreased E-Cadherin expression.Our findings may explain higher ARMS aggressiveness. Moreover, we suggest that further studies should be performedto verify if Snail1 can be considered as a potential target for ARMS therapy.

  18. [Natural growth and decline of Oncomelania hupensis snails in marshland of Qianliang Lake District in Eastern Dongting Lake area, China].

    Science.gov (United States)

    Li, Lin-han; Zhou, Yi-biao; Yao, Bao-dong; Wu, Jin-yi; Zheng, Sheng-bang; Song, Xiu-xia; He, Zhongz; You, Jia-bian; Cai, Bin; Zhao, Gen-ming; Jiang, Qing-wu

    2013-08-01

    To understand the change trend of Oncomelania hupensis snails in the bottomland areas of Qian Liang Lake district in Eastern Dongting Lake area so as to provide the evidence for formulating a schistosomiasis control strategy. The monitoring data of snails of Qianliang Lake district from 1988 to 2011 were collected retrospectively and analyzed by using the method of the trend Chi-square test. The correlations among the snail density indicators were analyzed. 1988 to 2011, the area of snails surveyed did not change and was 433.2 hm(2). The monitoring data showed that the change trend of the density of living snails and the schistosome infection rates of snails were not obvious (P > 0.05), but the mortality of snails showed a falling trend (P snails and the mortality of snails (r = 0.640, P snails (r = 0.639, P snails (r = 0.646, P snail indicators. In 1999, only 7 snails were found, of them, only one snail was alive. The alive snails were not found after 2000. In the bottomland areas of Qianliang Lake district, the change trend of the density of alive snails were not obvious from 1988 to 1998, but the number of snails underwent a sharp drop in 1999 and snails have been not found till now.

  19. 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

    2011-01-01

    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 changes. This

  20. 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

  1. COMPOSITION OF FAUNA AND DISTRIBUTION OF LAND SNAILS IN INTRAMONTANE DAGESTAN

    National Research Council Canada - National Science Library

    L. J. Harutyunova; M. Z. Magomedova

    2016-01-01

    Aim. Taxonomy of Caucasian land snails has been studied well enough, but at the same time, the question remains concerning the distribution of some species of snails on the main areas of the Caucasus...

  2. [Relationship between snails and recent water level in different marshlands in Xingzi County, Jiangxi Province].

    Science.gov (United States)

    Wang, Zeng-Liang; Zhao, Fei; Zhang, Zhi-Jie; Yao, Bao-Dong; Jiang, Qiu-Lin; Tao, Bo; Zhai, Min-Ling; Jiang, Qing-Wu

    2013-02-01

    To study the longitudinal change of data on Oncomelania hupensis surveillance in different marshlands and the impact of recent water level in Xingzi County, Jiangxi Province. All information including water level of hydrometric station and the data of snails at the marshlands of Xiguanhu, Majiawan and Ximiaoqian was collected to explore the longitudinal change of snails and analyze the relationship between snail distribution and recent water level with Spearman rank correlation analysis. The highest proportion of frames with living snails and living snail densities at Majiawan and Ximiaoqian was 89.66% (442/493) in 2002 and 66.72% (872/1 307) in 2007, 8.33 in 2001 and 7.39 snails per frame in 2006, respectively, and the lowest was 13.26% (126/950) in 2010 and 4.60% (55/1 195) in 2005, 0.42 in 2010 and 0.22 snails per frame in 2002, respectively, and tended to decrease gradually after 2007. At Majiawan, infected snails were found in 2005 and 2009, the density and proportion of infected snails were 0.0033 and 0.0025 snails per frame, 0.09% (3/3 306) and 0.22% (3/1 389). Infected snails were found in Ximiaoqian in 2001, 2003, 2005 and 2009, the highest density and proportion of infected snails were 0.005 0 snails per frame and 0.88% (6/684) in 2005. Infected snails were found in Xiguanhu in 2002 and 2003 with a density and proportion of 0.0029 and 0.0027 snails per frame, 0.10% (1/974) and 0.32% (1/312), respectively. The correlation analysis between proportion of frames with living snails and density at Xiguanhu with the average water level of the first and second month before snail survey showed statistical significance, the correlation coefficient was 0.76, 0.71, 0.82 and 0.78 (Psnails and density at Majiawan showed no statistical significance with the average water level of recent three months before snail survey. The proportion of frames with living snails and density at Xiguanhu were negatively correlated with the average water level of the first and second

  3. Fluorescent pigment distinguishes between sibling snail species.

    Science.gov (United States)

    Seki, Keiichi; Wiwegweaw, Amporn; Asami, Takahiro

    2008-12-01

    Traditional taxonomy of shell-bearing molluscs does not generally use soft-body coloration. However, the land snails Bradybaena pellucida and B. similaris have been distinguished only on the basis of the color of the soft-body visible through the shell. Thus, the taxonomic status of the two species has traditionally been questionable. We found that dense spots of pigments embedded in the dorsal mantle are responsible for the yellow coloration of B. pellucida . Similar spots in B. similaris are white and less densely aggregated in whorls further from the apex, and the brown color of the hepatopancreas is visible through the shell. The yellow pigments of B. pellucida seep out with mucus from the body in natural and laboratory conditions. The two species became externally indistinguishable after 30 days of laboratory feeding, because the yellow spots disappeared in B. pellucida and the color of the hepatopancreas changed from dark brown to pale brown in both species. Irradiation with ultraviolet A demonstrated that the yellow pigment of B. pellucida fluoresces. Adult specimens of the two species were distinct in penial microsculpture, with F(1) hybrids intermediate in form. Populations of the two species differed significantly in allelic frequencies at four allozyme loci. Therefore, B. pellucida and B. similaris are morphologically and genetically distinct. The fluorescent yellow pigment distinguishes B. pellucida from B. similaris under natural conditions despite its environmental dependence.

  4. The feeding habits of the snail kite in Florida, USA

    Science.gov (United States)

    Sykes, P.W.

    1987-01-01

    The feeding habits of the Snail Kite (Rostrhamus sociabilis) were observed intermittently from 1967-1980 in Florida, USA. Approximately 97% of all observed foraging bouts were over marshes having sparse emergent vegetation. The visually-hunting kite was unable to forage over floating mats of exotic water hyacinth (Eichhornia crassipes). Male kites had shorter hunting bouts than females. For still-hunting, the birds' perches ranged from 0.15-4.6 m high and captures occurred an average of 5.8 m from perches. Females were significantly more successful (70%) for course-hunting than males (48%), but I found no difference for still-hunting. Birds tended to forage throughout the day, except for occasional inactive periods by some individuals during midday. On cooler days, foraging commenced slightly later in the morning than on warmer days. Kites probably capture freshwater apple snails (Pomacea paludosa) as deep as 16 cm. Capture rates for adults generally ranged from 1.7-3.4 snails per hour. Kites usually foraged over a common hunting area, and defense of foraging sites was rare. Handling of snails, from the kite's arrival at the feeding perch unit consumption, averaged 2.7 min, with no significant difference between sexes. However, adult females were more efficient at the extraction portion of this process than were adult males. Snails were usually extracted before being brought to the nest, except in the latter part of the nestling period when some snails were extracted at or near the nest and some were brought intact. Adults feed small chicks bill to bill, and both parents generally shared equally in care of the young, except at two nests where the females did 67% or more of the feeding. Mean length of snails taken by kites was 42.8 mm (range 25.2-71.3 n=697) and mean diameter was 45.8 mm (range 27.4-82.4, n=697). The most common size classes tkaen were 30-60 mm in length and diameter. Nutritional and gross energy values were determined for apple snails. Female

  5. Snails Composition in the Southern Part of Gunung Halimun National Park

    OpenAIRE

    Heryanto, Heryanto

    2001-01-01

    Snails inventory in the southern part of Gunung Halimun National Park (GHNP) was conducted in two locations i.e., Ciptarasa and Simaresmi,in July and November 2000.It was found 36 species of snails that belongs to 16 families.It means that snails in the southern part of GHNP differs from that of the central part of the Park. Those snails were discovered in 9 habitat types.

  6. Helix and Drugs: Snails for Western Health Care From Antiquity to the Present

    OpenAIRE

    Bruno Bonnemain

    2005-01-01

    The land helix, or snail, has been used in medicine since antiquity and prepared according to several formulations. This historical report traces the understanding of their properties from the time of Hippocrates, who proposed the use of snail mucus against protoccle and Pliny who thought that the snail increased the speed of delivery and was “a sovereign remedy to treat pain related to burns, abscesses and other wounds”, Galien recommended snails against hydrops foetails. In the 18th centu...

  7. [Study on shell shape changes of filial generation Oncomelania hupensis snails in Weishan Lake region, Shandong Province].

    Science.gov (United States)

    Miao, Feng; Liu, Xin; Wang, Li-Lei; Deng, Xu-Li; Chen, Xi-Xin; Fu, Zhao-Yi; Wang, Yong-Bin

    2014-02-01

    To explore the shape change characteristics of Oncomelania hupensis snail shell after the snails being passively migrated into Shandong intake area of the South-to-North Water Diversion Project. The snails raised on the Dushan island in Weishan Lake region were captured, and 115 the first filial generation snails and 107 the second filial generation ones were selected. The length and width of shells and apertures, and the labial ridge thickness of those snails were measured, the longitudinal rib number of snail spiral was counted, and 107 parental snails were chosen as controls. The labial ridge thickness of the filial generation snail was significantly reduced with the increase of algebras, and the labial ridge thickness among the 3 generations had a significant difference (P snail shell and the width of snail apertures were decreased, while the width of snail shell, the length of snail apertures, the multiplication product of snail aperture's length and width and the longitudinal rib number of snail spiral were all increased. The body size of Oncomelania snails in Weishan Lake region becomes smaller, and their shells become thinner, which indicates that the environment of the lake region is not suitable for snail breeding, and the snails have natural decay tendency with the extension of time.

  8. Snails promote methane release from a freshwater lake ecosystem

    Directory of Open Access Journals (Sweden)

    Xiao eXu

    2014-05-01

    Full Text Available Benthic fauna, as ecosystem engineers, can strongly affect microbial-driven ecosystem biogeochemical cycling. However, the effects of benthic fauna, especially epifauna, on CH4 cycling remain still elusive. In this study, CH4 effluxes were both measured along a gradient of snail density in a freshwater lake ecosystem in China, and monitored in manipulated laboratory microcosms with and without snails. Field CH4 efflux was significantly increased with snail density. Likewise, the stimulating effects of freshwater snails on CH4 effluxes were evident in the homogenised indoor microcosms. These results show that snails can stimulate CH4 efflux in the freshwater lake ecosystem. Moreover, the average efflux of CH4 emitted from snails’ habitats has reached 15.33 mg CH4-C m-2 d-1. By comparing with those emitted from vegetated coastal marsh and alpine wetland, this data indicates that snails’ habitats are strong sources of CH4 in a freshwater ecosystem. This study suggests identifying and modeling epifauna activity as a function of CH4 cycling could improve the mechanistic understanding of wetland biogeochemical cycling responses to climate change.

  9. Implication of Snail in Metabolic Stress-Induced Necrosis

    Science.gov (United States)

    Ju, Min Kyung; Moon, Ji Young; Park, Hye Gyeong; Yoo, Mi-Ae; Choi, Byung Tae; Yook, Jong In; Lim, Sung-Chul; Han, Song Iy; Kang, Ho Sung

    2011-01-01

    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. PMID:21448462

  10. Aquatic snail species of two adjoining rivers in Owerri, Imo State ...

    African Journals Online (AJOL)

    Aquatic snail species of two adjoining Rivers (Otamiri and Nwaorie Rivers) in Owerri Southeastern Nigeria was surveyed between December 2008 and May 2009. The study identified 231 aquatic snail species. Snail species collected were Bulinus globosus (29.9%), Lymnaea natalensis (59.3%), and Melanoides sp.

  11. Vineyard snail allergy possibly induced by sensitization to house-dust mite (Dermatophagoides pteronyssinus)

    NARCIS (Netherlands)

    de Maat-Bleeker, F.; Akkerdaas, J. H.; van Ree, R.; Aalberse, R. C.

    1995-01-01

    A female patient experienced a severe allergic reaction after consumption of vineyard snails. The patient proved to be sensitized to house-dust mite (HDM) and demonstrated a positive skin test and specific IgE to snail (Eobania vermiculata, Lofarma). The snail RAST was > 80% inhibited by HDM,

  12. New scope on the relationship between rotifers and Biomphalaria alexandrina snails

    Science.gov (United States)

    Mossallam, Shereen Farouk; Amer, Eglal Ibrahim; Abou-El-Naga, Iman Fathy

    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. PMID:23905015

  13. Helix and Drugs: Snails for Western Health Care From Antiquity to the Present.

    Science.gov (United States)

    Bonnemain, Bruno

    2005-03-01

    The land helix, or snail, has been used in medicine since antiquity and prepared according to several formulations. This historical report traces the understanding of their properties from the time of Hippocrates, who proposed the use of snail mucus against protoccle and Pliny who thought that the snail increased the speed of delivery and was "a sovereign remedy to treat pain related to burns, abscesses and other wounds", Galien recommended snails against hydrops foetails. In the 18th century, various snail "preparations" were also recommended for external use with dermatological disorders and internally for symptoms associated with tuberculosis and nephritis. Surprisingly, the 19th century saw a renewed interest in the pharmaceutical and medical use of snails with numerous indications for snail preparations. This interest in snails did not stop at the end of the 19th century. The 1945 edition of Dorvault devotes an entire paragraph to snails, indicating that the therapeutic usage of snails was still alive at that time. Recently the FDA has also shown an interest in snails. Ziconotide (SNXIII), a synthetic peptide coming from snail venom, has been under FDA review since 1999. Pre-clinical and clinical studies of this new drug are promising.

  14. Helix and Drugs: Snails for Western Health Care From Antiquity to the Present

    Directory of Open Access Journals (Sweden)

    Bruno Bonnemain

    2005-01-01

    Full Text Available The land helix, or snail, has been used in medicine since antiquity and prepared according to several formulations. This historical report traces the understanding of their properties from the time of Hippocrates, who proposed the use of snail mucus against protoccle and Pliny who thought that the snail increased the speed of delivery and was “a sovereign remedy to treat pain related to burns, abscesses and other wounds”, Galien recommended snails against hydrops foetails. In the 18th century, various snail “preparations” were also recommended for external use with dermatological disorders and internally for symptoms associated with tuberculosis and nephritis. Surprisingly, the 19th century saw a renewed interest in the pharmaceutical and medical use of snails with numerous indications for snail preparations. This interest in snails did not stop at the end of the 19th century. The 1945 edition of Dorvault devotes an entire paragraph to snails, indicating that the therapeutic usage of snails was still alive at that time. Recently the FDA has also shown an interest in snails. Ziconotide (SNXIII, a synthetic peptide coming from snail venom, has been under FDA review since 1999. Pre-clinical and clinical studies of this new drug are promising.

  15. Survey of snail intermediate hosts of trematodes in Jos South Local ...

    African Journals Online (AJOL)

    Streams and irrigation schemes in selected areas of Jos South Local Government Area, Plateau State, Nigeria were surveyed for snail intermediate hosts of Trematodes. A total of 1045 snails were collected from streams with long handled scoop net and in some areas manually with hand in gloves. The snails were put in ...

  16. Evaluation Of Snail Mucin Dispersed In Brachystegia Gum Gel As A ...

    African Journals Online (AJOL)

    Snail mucin was obtained from the mucilage of Archachatina marginata (Family Arionidae). The wound healing effect of the snail mucin was evaluated wth special attention to the effect when combined with honey in Brachystegia eurychoma gel preparation. Brachystegia eurycoma gum, snail mucin and honey were ...

  17. Analysis of land snail marketing in Owerri agricultural zone of Imo ...

    African Journals Online (AJOL)

    The study was conducted in Owerri Agricultural Zone of Imo state, Nigeria to assess the profitability of snail marketing during wet and dry seasons, examine the socioeconomic characteristics of the traders, identify and described the snail marketing channels and determine the economic efficiency of snail marketing for the ...

  18. Survey of snail intermediate hosts of trematodes in Jos South Local ...

    African Journals Online (AJOL)

    No snail was found in the irrigation schemes. The infected Lymnea snails were collected from a stream at the National Institute for Policy and Strategic Studies Kuru/Vom, while the Lymnea snails collected from other sites were not infected. The result indicated that the inhabitants of these areas may not harbor schistosomes ...

  19. New scope on the relationship between rotifers and Biomphalaria alexandrina snails.

    Science.gov (United States)

    Mossallam, Shereen Farouk; Amer, Eglal Ibrahim; Abou-El-Naga, Iman Fathy

    2013-08-01

    To investigate the effect of rotifer internalization into snail tissue on the development of schistosomes. 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. 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. In future biological control strategies of schistosomiasis, ritifers should be considered as a parasitic scourge of humanity.

  20. 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...

  1. Allocative efficiency constraints in snail (Archachatina marginata production by small scale snail farmers in Cross River State, Nigeria

    Directory of Open Access Journals (Sweden)

    Ignatius B. Adinya

    2011-11-01

    Full Text Available This study examined constraints militating against the profitability potentials of snail (Archachatina marginata production by small-scale snail farmers in Cross River State, Nigeria. Data were obtained from a random sample of 120 respondents in the study area by means of structured and semi-structured questionnaire. The first stage involved random selection of three (Ogoja, Ikom and Odukpani local government areas from eighteen local government areas in Cross River State, Nigeria. This was followed by random selection of three villages (Igoli in Ogoja Local Government Area, Alesi in Ikom Local Government Area and Adiabo in Odukpani Local Government Area in Cross River State. The respondents were randomly selected from each of the villages, 40 respondents were selected each from three villages, making a total number of 120 respondents. Data collected were analyzed using descriptive statistics and costs returns analysis. The results indicated that Cobb-Douglas production function had the best fit in explaining the relationship between output of snail and inputs used, the coefficient of multiple determinant (R2=0.60 indicates that sixty percent of the variability in output of snail is explained by the independent variables. Results from the analysis revealed that the marginal value products of farm size, labour, farm management practices and operating costs were N1080, N20.6, N972.8, N14.84 respectively, there existed allocative inefficiency, there is a high potential for snail farmers to increase their yields and income. Further analysis of results revealed that net returns on snail is N2,935,000.00 with return on every naira invested of N0.14 is also positive indicating a profit from the business, with attractive net return on investment. This study shows that snail farmers are faced with several problems in their production activities. These problems or constraints affect the efficiency of snail production in the study area. Notable among them

  2. [Classification and grading of environments with Oncomelania hupensis snails inside embankment of marshland and lake areas].

    Science.gov (United States)

    Peng, Xiao-Wu; Rong, Xian-Bing; Zhang, Hua-Ming; Liu, Heng-Wu; Wang, Jia-Song; Liu, Xiong; Zhang, Xia; Chen, Mei; Cui, Cai-Xia; Dong, Juan; Guo, Shu

    2014-02-01

    To classify and grade the environments with Oncomelania hupensis snails inside embankment in marshland and lake areas, so as to improve the work efficiency and realize the systematic management. The schistosomiasis endemic area Liaodi and Xiongdi villages in Jiangling County, Hubei Province were selected as the experiment villages, and the environments with snails in the two villages were divided into sections with a length of 500 m, then the snail situation were surveyed by the systematic sampling method with 10 m and 50 m a frame respectively. The environments were classified according to the discovery of infected snails and wild fecal contamination, and the numbers of sites with snails and their areas in different classes were recorded. Meanwhile, the data of sites with infected snails in Jingzhou City during the recent 5 years were collected and graded according to the average density of snails, so as to discuss the correlativity between the grades of environments with snails and the numbers of sites with infected snails and the occurrence rate of frames with snails. There were 1 967 sites with infected snails in Jingzhou City during the recent 5 years, and there was a positive correlation between the grades of environments with snails and the occurrence rate of frames with snails (r(s) = 0.77, P snails was 3.1%, and when the grade was 2-3, the ratio raised to 56.3%. There were 39 sites with snails in the two villages, the Class 1, 2 and 3 environments included 1, 18 and 20 sites, with the areas of 1080, 51,640 m2 and 41,220 m2, respectively. There were no statistically significant difference between the grades divided by snail survey with 10 m and 50 m a frame ( chi2 = 4.667, P > 0.05), but the time-consuming of the former was 3 times of the latter. The classification and grading of the environments with snails inside embankment in marshland and lake areas can master the key point of the snail survey. The subsection and setting frames at a suitable distance

  3. Hitchhiking behaviour in the obligatory upstream migration of amphidromous snails

    Science.gov (United States)

    Kano, Yasunori

    2009-01-01

    Migratory animals endure high stress during long-distance travel in order to benefit from spatio-temporally fluctuating resources, including food and shelter or from colonization of unoccupied habitats. Along with some fishes and shrimps, nerite snails in tropical to temperate freshwater systems are examples of amphidromous animals that migrate upstream for growth and reproduction after a marine larval phase. Here I report, to my knowledge, the first example of ‘hitchhiking’ behaviour in the obligatory migration of animals: the nerite snail Neritina asperulata appears to travel several kilometres as minute juveniles by firmly attaching to the shells of congeneric, subadult snails in streams of Melanesian Islands, presumably to increase the success rate of migration. PMID:19411267

  4. 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

  5. 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. © 2015 Wiley Periodicals, Inc.

  6. 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.

  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. [Spatial regression analysis of relationship between schistosome infection rate of Oncomelania hupensis snails and climate factors].

    Science.gov (United States)

    Chen, Yan-yan; Iu, Jian-bing; Xiao, Ying; Zhou, Xiao-rong; Jiang, Yong; Dai, Ling-feng; Cai, Shun-xiang

    2015-04-01

    To explore the relationship between the schistosome infection rate of O. hupensis snails and the climate factors in endemic areas of schistosomiasis, so as to provide the evidence for improving the snail control. The snail and climate data of 18 counties in Hubei Province in 2009 were collected to obtain the infection rate of O. hupensis snails and to fit the spatial regression models. The multiple linear regression model showed that the residuals were autocorrelated (Moran's I = 0.182 8, P snails was positively correlated with the annual average temperature (P 0.05). The spatial regression models could be well applied in the analysis of the relationship between the O. hupensis snails and climate factors. The annual average temperature is the primary climate factor influencing the infection of O. hupensis snails.

  9. 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

  10. Differences in predatory pressure on terrestrial snails by birds and ...

    Indian Academy of Sciences (India)

    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.

  11. Snail abundance in freshwater canals in the eastern province of ...

    African Journals Online (AJOL)

    Ksu-network

    2012-07-19

    Jul 19, 2012 ... succincta historia. Volumen alterum. pp. I-XXVI [= 1-36], 1-214, [1-. 10]. Havniæ & Lipsiæ. (Heineck & Faber). page 191. Opisa S, Odiere MR, Jura WGZO, Karanja DMS, Mwinzi PNM (2011). Malacological survey and geographical distributionof vector snails for schistosomiasis within informal settlements of ...

  12. 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.

  13. Biochemical evaluation of aestivation and starvation in two snail ...

    African Journals Online (AJOL)

    hope&shola

    2010-11-08

    Nov 8, 2010 ... aestivation and starvation on endogenous metabolic reserves in haemolymph of two snail species namely: Bulinus globosus (Morelet) and ..... predicator of kidney function/disorder as urea level in the blood indicates kidney disorder. .... Urea and uric acid contents in the hepatopencreas, kidney and lung of ...

  14. Macro-invertebrate predatorsof freshwater pulmonate snails in Africa ...

    African Journals Online (AJOL)

    A range of African and alien macro-invertebrates has been reported preying on freshwater pulmonate snails, including those that serve as intermediate hosts for bloodflukes of the genus Schistosoma. Predation by five molluscivorous taxa is reviewed here: indigenous leeches (Glossiphoniidae), marsh fly larvae ...

  15. Snail Shells in a Practical Application of Statistical Procedures

    Science.gov (United States)

    Banks, Stephen W.; Shepherd, Deborah K.; Williams-Hart, Tara; Gossett, Dalton R.; Crnkovic, Amanda C.

    2007-01-01

    This paper is based upon a laboratory exercise designed for biology students in secondary schools or those taking introductory biology laboratory courses in colleges and universities. This exercise requires a set of calipers, a calculator and populations of snail shells collected either from the wild or obtained from a biological supply house. The…

  16. Molecular diversity of avian schistosomes in Danish freshwater snails

    DEFF Research Database (Denmark)

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

    2016-01-01

    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...

  17. Aspects of Water Quality of Freshwater Systems Harbouring Snail ...

    African Journals Online (AJOL)

    A study of some aspects of water quality of freshwater systems harbouring snail vectors of schistosome parasites was conducted in Jos, Nigeria. Calcium ion concentration of the water bodies was a mean value of 31 mg.l-1. The range of temperature was 15 - 30OC. The occurrence of Biomphalaria pferifferi was attributed to ...

  18. Shell colouration and parasite tolerance in two helicoid snail species.

    Science.gov (United States)

    Scheil, Alexandra E; Hilsmann, Stefanie; Triebskorn, Rita; Köhler, Heinz-R

    2014-03-01

    The polymorphism of shell colouration in helicoid snails is a well-known phenomenon attributed to different factors such as predation and climatic effects. Another aspect contributing to this polymorphism could be the interplay of melanin production and phenoloxidase-related immunity. Therefore, in this study we aimed at answering the questions whether there is a differential sensitivity of different snail shell colour morphs to nematode infection, and whether this can be related to differences in phenoloxidase (PO) activity levels using the two helicoid, polymorphic snail species Cepaea hortensis and Cernuella virgata. Snails of both species were artificially infected with the parasitic nematode Phasmarhabditis hermaphrodita, and analysed for mortality and PO activity levels. We found C. virgata to be more severely affected by P. hermaphrodita infection than C. hortensis, and the dark C. virgata morphs to be more resistant to lethal effects of this infection than pale morphs. However, these differences in sensitivity to the parasite could not clearly be related to different PO activity levels. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Prevalence of Snail Vectors of Schistosomiasis in the Kpong Head ...

    African Journals Online (AJOL)

    Administrator

    Introduction. Schistosomes (blood flukes) are digenetic trematodes of the super family Schistoso- matoidea. They cause the disease schistoso- miasis, which is commonly called bilharziasis. The parasites undergo part of their developmental phase into infective forms in water borne planorbid snails. Hence, schistosomiasis ...

  20. Food Choice in the Common Snail (Helix Aspersa).

    Science.gov (United States)

    Gill, John; Howell, Pauline

    1985-01-01

    The easily obtained common snail shows interesting dietary preferences which can be the source of several simple experiments. Specific student instructions are given for quantitative and comparative studies using cabbage, lettuce, carrot, rutabaga, and onion. Suggestions for laboratory setup and further work are included. (DH)

  1. Reproductive anomalies in stenoglossan snails related to pollution from marinas

    Energy Technology Data Exchange (ETDEWEB)

    Smith, B.S.

    1981-02-01

    Over 3090 snails of the dioecious intertidal species Nassarius obsoletus Say were collected from a total of 71 localities. Their reproductive anatomy was examined for a superimposition of male characteristics on to the normal female anatomy, an abnormality called 'imposex'. Imposex was rated numerically in terms of the fraction of the population affected and the intensity of expression in bearer snails. An initial survey of 22 localities in Fairfield and Westport, Connecticut, led to the hypothesis that imposex was related to a substance arising from marinas. This was tested at nine pairs of marina and control localities in Long Island Sound, as well as six pairs along a transect ranging from Rhode Island to Georgia. Imposex scores were significantly higher at the marina locality in every pair. Further confirmation was found in a detailed survey of the estuarine harbor at Southport, Connecticut, which showed that adjacent populations could differ in the amount of imposex to the extent that both the snails and the waters they lived in remained separated by natural or man-made barriers. Imposex has been found in populations of N. obsoletus ranging from Damariscotta, Maine, to Savannah, Georgia, and it has been reported from San Francisco Bay, California. Similar anatomical abnormalities have been reported in at least 27 other species of taenioglossan and stenoglossan snails, extending the range to the Atlantic and Mediterranean coast of Europe and the British Isles. Concern is raised regarding the possible existence of another global pollutant with novel effects on marina biota.

  2. Response of Oncomelania snail distribution on land use in Sichuan ...

    African Journals Online (AJOL)

    Response of Oncomelania snail distribution on land use in Sichuan, China. Q Sun, Z Peng, J Zhang, J Jiang. Abstract. Schistosomiasis is one of the four major infectious diseases that require prevention and control in China. It is mainly distributed along the middle and downstream areas of the Yangtze River and some hilly ...

  3. Effects of feeding adult snails Stylosanthes guianensis or Lablab ...

    African Journals Online (AJOL)

    SERVER

    2007-08-20

    Aug 20, 2007 ... with the use of electric weighing balance. Shell length and width were measured on weekly basis with the use of vernier caliper while shell thickness was measured every week with micrometer screw gauge. Feed conversion ratio was calculated as the ratio of feed intake to weight gain. Twelve snails from ...

  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. Oxygen consumption and responses of the freshwater snail Bulinus ...

    African Journals Online (AJOL)

    A gradient or choice apparatus, based on the 'fluvarium' principle and suitable for testing the responses of the freshwater snail Bulinus (Physopsis) globosus to different partial oxygen tensions was used. In a gradual oxygen gradient established with this apparatus, B. (P.) globosus shows a significant preference for ...

  6. Studies on seasonal variations in the gut contents of snail ...

    African Journals Online (AJOL)

    ... and various forms of algae, macrophyte tissue and spore-like materials. For the two species, the quality as well as quantity was seen to vary probably with seasonal changes in their habitat flora and fauna. Keywords: Bulinus rohlfsi, Bulinus globosus, schistosomiasis, gastropod snails. Nigerian Journal of Parasitology Vol.

  7. Foraging Behaviour Responses in the African Giant Land Snail ...

    African Journals Online (AJOL)

    Results indicated T1 with highest tentacle lowering; T2 indicated an acquisition effect; T3 indicated latent inhibition effect; T4 indicated over shadowing effect between paired odour. The A. achatina demonstrated at least 7 days of odour memory retention. The immediate significance of this study is that snail farmers should ...

  8. Distribution and habitats of Biomphalaria pfeifferi , snail intermediate ...

    African Journals Online (AJOL)

    This snail is well represented in the Northern Province, Mpumalanga and the coastal areas of KwaZulu-Natal, that represent the bilharzia endemic areas of South Africa. Details of each habitat, as well as mean altitude and mean annual temperature and rainfall of each locality, were processed to determine chi-square and ...

  9. Differences in predatory pressure on terrestrial snails by birds and ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Biosciences; Volume 36; Issue 4. Differences in predatory ... Articles Volume 36 Issue 4 September 2011 pp 691-699 ... larger individuals. Significant differences in their predatory pressure can influence the evolution and maintenance of shell size and polymorphism of shell colouration in snails.

  10. Zoonotic helminths in fresh water snail ( Melanoides tuberculata ...

    African Journals Online (AJOL)

    We investigated 3 study sites of rural wetland communities of Ikpa, Ibikpe and Ikot Udo for helminth parasites using water snail Melanoides tuberculata fresh ... helminth egg/L. Helminths co-infection as outlined is a neglected emerging zoonosis, as these could increase livestock and public health disease burden in wetland ...

  11. 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...... to juvenile fish raised in carp nurseries....

  12. Expression and activity of SNAIL transcription factor during Epithelial to Mesenchymal Transition (EMT in cancer progression

    Directory of Open Access Journals (Sweden)

    Izabela Papiewska-Pająk

    2016-09-01

    Full Text Available 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 fromproteasomal 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.

  13. [Effect of modified crushing-cercariae escaping method on detection of infected Oncomelania snails in field].

    Science.gov (United States)

    He, Liang-Cai; Wang, Jia-Song; Li, Hua-Zhong; Rong, Xian-Bing; Yuan, Mei-Zhi; Peng, Xiao-Wu; Zhu, Shao-Liang; Wang, Lu; He, Zheng-Wen; Yang, Zhi-Qiang; Hong, Min; Su, Wen; Li, Jun

    2012-02-01

    To evaluate the effect of a modified crushing-cercariae escaping method on the detection of infected Oncomelania snails in the field. A snail survey was carried out in Jingzhou City in the spring of 2011, and the villages were randomly divided into several groups, the coincidence rates, detection rates and the labour cost of the modified crushing-cercariae escaping method and crushing method were compared. A total of 14 snail spots were surveyed, and the coincidence rate of the two methods was 100%. In the spring snail survey, 539 villages and 3 536 spots with snails were detected by the modified crushing-cercariae escaping method, and 671 villages and 11 375 spots with snails were detected by the crushing method. The detection rates of villages with infected snails of the two methods were 25.79% and 28.46%, respectively, the difference between them was not statistically significant (chi2 = 1.079 5, P > 0.05); and those of spots with infected snails were 5.57% and 3.66%, respectively, which had no significant difference between them (chi2 = 95.464 1, P snails quickly and accurately with less labour cost, therefore, it is suitable for detecting environments with infected snails in batch in endemic areas.

  14. [Causes of re-emergence of Oncomelania snails in hardened ditches].

    Science.gov (United States)

    Ding, Zhao-Jun; Wui, Jia-Ping; Wang, Dao-Fen; Wei, Zhang-Yong; He, Bin; He, Ya-Lan; Yu, Yun-Song; Wan, Jun

    2013-04-01

    To understand the impact factors of the re-emergence of Oncomelania snails in hardened ditches so as to find out the measures to improve the effect of snail eradication. Thirteen infected townships from Jingmen City were randomly selected and investigated with the retrospective method and the field survey. All the data were analyzed for evaluating the effect of the hardened ditches on snail eradication and finding out the causes of the re-emergence of snails in hardened ditches After on-site investigation of 151 hardened ditches, the eradication rate of snail areas was 78.79%, and 71 ditches were founded with snails and the re-emergence rate was 47.02%. The major factors of the snail re-emergence were the spread of the snails from the upstream, the dilapidation of the hardened ditches, no using molluscicides before the hardened ditches, and the snails being brought by the engineering construction. The only hardened ditches can not eradicate the snails. We should manage an overall plan when processing the ditches hardening project, implementation with molluscicides before the project and strengthen the maintenance of the hardened ditches.

  15. Snail and serpinA1 promote tumor progression and predict prognosis in colorectal cancer.

    Science.gov (United States)

    Kwon, Chae Hwa; Park, Hye Ji; Choi, Jin Hwa; Lee, Ja Rang; Kim, Hye Kyung; Jo, Hong-Jae; Kim, Hyun Sung; Oh, Nahmgun; Song, Geun Am; Park, Do Youn

    2015-08-21

    The role of Snail and serpin peptidase inhibitor clade A member 1 (serpinA1) in tumorigenesis has been previously identified. However, the exact role and mechanism of these proteins in progression of colorectal cancer (CRC) are controversial. In this study, we investigated the role of Snail and serpinA1 in colorectal cancer (CRC) and examined the mechanisms through which these proteins mediate CRC progression. Immunohistochemical analysis of 528 samples from patients with CRC showed that elevated expression of Snail or serpinA1 was correlated with advanced stage, lymph node metastasis, and poor prognosis. Moreover, we detected a correlation between Snail and serpinA1 expression. Functional studies performed using the CRC cell lines DLD-1 and SW-480 showed that overexpression of Snail or serpinA1 significantly increased CRC cell invasion and migration. Conversely, knockdown of Snail or serpinA1 expression suppressed CRC cell invasion and migration. ChIP analysis revealed that Snail regulated serpinA1 by binding to its promoter. In addition, fibronectin mediated Snail and serpinA1 signaling was involved in CRC cell invasion and migration. Taken together, our data showed that Snail and serpinA1 promoted CRC progression through fibronectin. These findings suggested that Snail and serpinA1 were novel prognostic biomarkers and candidate therapeutic targets in CRC.

  16. Lentivirus-delivered short hairpin RNA targeting SNAIL inhibits HepG2 cell growth.

    Science.gov (United States)

    Liu, Jing; Jiang, Gang; Liu, Shihai; Liu, Zimin; Pan, Huazheng; Yao, Ruyong; Liang, Jun

    2013-09-01

    Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related mortality worldwide, and the highest incidence rates are reported in East Asia. We previously showed that SNAIL is upregulated in HCC tissues. In the present study, we aimed to investigate RNA interference-mediated targeting of SNAIL on the growth of HepG2 cells. We constructed three RNA interference plasmids targeting the SNAIL gene and selected the most efficient shRNA expression cassette. After the lentivirus (LV)-SNAIL small interfering (si)RNA vector was transfected into the HepG2 cell line, cell proliferation was measured using the MTT assay. E-cadherin mRNA and protein expression levels were examined by quantitative PCR and western blotting, respectively. We successfully constructed an LV-SNAIL siRNA lentiviral vector and demonstrated that it suppressed the expression of the SNAIL gene in HepG2 cells. RNA interference of SNAIL by the LV-SNAIL siRNA construct significantly inhibited the growth of HepG2 cells, in addition to significantly increasing E-cadherin mRNA and protein expression. Our findings strongly suggest that SNAIL and E-cadherin play a significant role in HCC progression, and exhibit a negative correlation. Furthermore, the expression of E-cadherin may be responsible for the reduced proliferation and survival of HepG2 cells. Thus, the SNAIL signaling pathway may provide a novel therapeutic target for the treatment of HCC.

  17. The Use of Golden Snail (Pomacea sp. as Animal Feed in the Philippines

    Directory of Open Access Journals (Sweden)

    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.

  18. 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. Copyright © 2011 Australian Society for Parasitology Inc. All rights reserved.

  19. 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.

  20. 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

    Science.gov (United States)

    Abou-El-Naga, Iman Fathy; Sadaka, Hayam Abd El-Monem; Amer, Eglal Ibrahim; Diab, Iman Hassan; Khedr, Safaa Ibrahim Abd El-Halim

    2015-01-01

    Of the approximately 34 identified Biomphalaria species,Biomphalaria alexandrina represents the intermediate host of Schistosoma mansoni in Egypt. Using parasitological and SOD1 enzyme assay, this study aimed to elucidate the impact of the age of B. alexandrina snails on their genetic variability and internal defence against S. mansoni infection. 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 Biomphalaria control. 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. PMID:26061235

  1. In Vitro Effects of Mucus from the Mantle of Compatible (Lymnaea elodes) and Incompatible (Helisoma trivolvis) Snail Hosts on Fascioloides magna Miracidia

    National Research Council Canada - National Science Library

    Kathyrn Coyne; Jeffrey R. Laursen; Timothy P. Yoshino

    2015-01-01

    The epidermal mucus covering the surface of a snail represents an important barrier to trematode larvae attempting to penetrate the snail and may play a role in mediating snail-trematode compatibility...

  2. Lumican Inhibits SNAIL-Induced Melanoma Cell Migration Specifically by Blocking MMP-14 Activity.

    Directory of Open Access Journals (Sweden)

    Marta Stasiak

    Full Text Available Lumican, a small leucine rich proteoglycan, inhibits MMP-14 activity and melanoma cell migration in vitro and in vivo. Snail triggers epithelial-mesenchymal transitions endowing epithelial cells with migratory and invasive properties during tumor progression. The aim of this work was to investigate lumican effects on MMP-14 activity and migration of Snail overexpressing B16F1 (Snail-B16F1 melanoma cells and HT-29 colon adenocarcinoma cells. Lumican inhibits the Snail induced MMP-14 activity in B16F1 but not in HT-29 cells. In Snail-B16F1 cells, lumican inhibits migration, growth, and melanoma primary tumor development. A lumican-based strategy targeting Snail-induced MMP-14 activity might be useful for melanoma treatment.

  3. [Dynamics and diffusion of Oncomelania snails in Danyang City, Jiangsu Province].

    Science.gov (United States)

    Jiang, Tao; Wang, Zhi-Jian; Zhu, Tao; Chao, Nong; Zhang, Xiao-Zhong; Wang, Jian-Ming

    2013-04-01

    To understand the dynamics and the diffusion trend of Oncomelania snails in Danyang City, Jiangsu Province, so as to explore effective control measures. The data of historical records and routine surveillance of snails were collected and analyzed according to the river systems. The snails were imported from external river systems and spread from the rivers to inland. The diffusion trend was from the upstream to downstream and from the rivers to irrigation canals. The inland rivers connecting with the Yangtze River are the main routes where marshland snails can spread from outside to the inland. The irrigation system plays an important role in snail spreading to the irrigation areas. The regular surveillance in combination with the basic construction of farmland and irrigation system is needed to prevent the spread of the snails and the retransmission of schistosomiasis japonica in Danyang.

  4. [Optimization of time of artificial population schistosome infected Oncomelania hupensis snails].

    Science.gov (United States)

    Xiong, Chun-Rong; Yao, Yun-Yi; Yang, Kun

    2013-12-01

    To explore the optimizational time of artificial population schistosome infected Oncomelania hupensis snails. Under laboratory conditions, the snails were infected with the miracidia of Schistosoma japonicum for 2 h, 3 h and 4 h respectively, and the death rates and the infection rates of the snails, and the quantities of cercariae of each group were observed 60-120 d after the infection, and all the data observed were analyzed to get the optimizational time of artificial population schistosome infected snails. Of the 3 h group, the snail infection rate was the highest and the mortality was the lowest among the 3 groups (P0.05). Under laboratory conditions, the optimizational time is 3 h in artificial population schistosome infected O. hupensis snails.

  5. Arsenic transfer and impacts on snails exposed to stabilized and untreated As-contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Coeurdassier, M.; Scheifler, R.; Mench, M.; Crini, N.; Vangronsveld, J.; de Vaufleury, A. [Universite de Franche-Comte, Besancon (France)

    2010-06-15

    An As-contaminated soil (Unt) was amended with either iron grit (Z), a coal fly ash (beringite, B) or B + Z (BZ) and placed in lysimeters in 1997. An uncontaminated soil (R) was also studied. In summer and autumn 2003, lettuces were cultivated in the lysimeters and snails were caged for one month. Lettuce As concentrations were higher during the summer, while no differences occurred in snails between seasons. Snail As concentrations ({mu} g g{sup -1} DW) ranged from 2.5 to 7.0 in B, Z and BZ, and peaked at 17.5 in Unt. In summer, snail survival was affected in Unt and Z compared to R and B while no mortality was noticed in autumn. Snail growth decreased only in B, BZ and Unt in autumn. Snail As concentrations suggest a risk for their predators even on the remediated soils.

  6. 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

  7. Nutritional and sensory profiling of the African giant land snail fed ...

    African Journals Online (AJOL)

    Meancholesterol level was very low (0.003 ± 0.0006 mg/100 g) in the snail. Negative correlation (r = -0.99; P < 0.05) was recorded between diet CF and moisture content of the snail meat, while feed EE had a positive correlation (r = 0.98; P < 0.05) with snail cholesterol level. Based on tastiness, toughness and tenderness of ...

  8. 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. MODULATION OF DEFENSIVE REFLEX CONDITIONING IN SNAILS BY SEROTONIN

    Directory of Open Access Journals (Sweden)

    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.

  10. Utilization Of Cassava and Pawpaw Diets By Growing Snails ...

    African Journals Online (AJOL)

    Two hundred and twenty five (225) growing snails of an average weight of 70g were used for the feeding trial, with five dietary treatments. The trial lasted fourteen weeks. The diets were isonitrogenous (18.30% crude protein) and Isocaloric (2500kcal/kg M. E). The treatments were T1, T2, T3, T4 and T5. The rations had 10% ...

  11. Molecular Identification of First Putative Aquaporins in Snails

    OpenAIRE

    Pieńkowska, Joanna R.; Kosicka, Ewa; Wojtkowska, Małgorzata; Kmita, Hanna; Lesicki, Andrzej

    2014-01-01

    Aquaporins (AQPs), also known as water channel proteins, are members of a large protein family termed Major Intrinsic Proteins (MIP). The mammalian AQPs have been most comprehensively described, while knowledge about AQPs in invertebrates is limited mainly to insects. Not a single AQP protein has been described in snails to date. Consequently, we decided to search for the proteins in gastropod representatives, namely Lymnaea stagnalis, Catascopia occulta, and Stagnicola palustris (Mollusca; G...

  12. 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

  13. Hitchhiking behaviour in the obligatory upstream migration of amphidromous snails

    OpenAIRE

    Kano, Yasunori

    2009-01-01

    Migratory animals endure high stress during long-distance travel in order to benefit from spatio-temporally fluctuating resources, including food and shelter or from colonization of unoccupied habitats. Along with some fishes and shrimps, nerite snails in tropical to temperate freshwater systems are examples of amphidromous animals that migrate upstream for growth and reproduction after a marine larval phase. Here I report, to my knowledge, the first example of ‘hitchhiking’ behaviour in the ...

  14. 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.

  15. [Effect of agroforestry model on inhibition of Oncomelania snails in plateau mountainous area of Yunnan Province].

    Science.gov (United States)

    Zhang, Chun-Hua; Tang, Guo-Yong; Liu, Fang-Yan; Li, Kun

    2012-10-01

    To evaluate the effect of agroforestry models on the inhibition of Oncomelania snails in the plateau mountainous area of Yunnan Province. The experimental field was established at Sanying Village of Eryuan County, Yunnan Province, where the "Flourishing Forest and Controlling Snails Project" was implemented. Different drought crops (alfalfa, vegetables, broad bean, garlic, lettuce, celery, green onions, and wheat) were intercropped under walnut forest in experimental groups, and the crops were not intercropped under walnut forest in a control group. The growth of forest, the change of snails and short-term income of residents were investigated. Agroforestry models promoted the forestry growth and effectively inhibited the growth of snails. There was a little snail in one of the experimental group that forest was intercropped with alfalfa (the occurrence rate of frames with living snails was 3.33%, the average density of living snails was 0.004/0.1 m2, and the declining rates were both 50.00%). The snails were not found in other intercropped models. The income of residents in the experimental groups increased (900-6 800 Yuan per year) compared with that in the control group. The model of walnut forest intercropped with crops not only has the obvious effect on inhibition of snails, but also has good economic and ecological benefits in the plateau mountainous area of Yunnan Province.

  16. Potential future applications of spermatheca extract from the marine snail Telescopium telescopium

    National Research Council Canada - National Science Library

    ROY, Subhasis; ROYCHOWDHURY, Uttio; DASGUPTA, Partha Sarathi; DATTA, Uttam; MUKHERJEE, Prasenjit; GHOSH, Debaki

    2010-01-01

    Cytosol fraction of spermatheca and/or the ovotestis gland from the marine snail Telescopium telescopiumwas found to have antimicrobial, antiprotozoal, antifertility, and immunomodulation properties...

  17. [Performance evaluation of small snail control projects in Hubei Province in 2009 and 2010].

    Science.gov (United States)

    Yang, Rui; Zhu, Zhi-Hua; Huang, Xi-Bao; Tan, Xiao-Dong

    2012-08-01

    To evaluate the performance of small Oncomelania snail control projects in Hubei Province in 2009 and 2010, so as to explore the best snail control project in different areas. The expense-effect, expense-efficiency and cost-utility analyses were carried out to analyze the small snail control projects with reference to the relevant schistosomiasis japonica prevention and control index system. The coverage rate of snail control was 40.15%, the decrease rate of the snail areas was 32.86%, the unit cost for the snail control was 0.39 Yuan/m2, the cost of reducing 1% of the snail area was 67.34 ten thousand Yuan, the total benefit was 15 554.14 ten thousand Yuan, the ratio of cost to benefit was 7.03, the net benefit was 13 341.44 ten thousand Yuan, and the ratio of cost to net benefit was 6.03, and the investment ratio was 1 : 2.11 in the 183 small snail control projects. There is an obvious and respectable short-period effect of the small snail control projects.

  18. Twist and Snail expression in tumor and stromal cells of epithelial odontogenic tumors.

    Science.gov (United States)

    Oh, Kyu-Young; Yoon, Hye-Jung; Lee, Jae-Il; Ahn, Sun-Ha; Hong, Seong-Doo

    2017-02-01

    The aims of this study were to evaluate expression of Twist and Snail in tumor and stromal cells of epithelial odontogenic tumors and to analyze relationships between Twist and Snail expression and between tumor and stromal expression. Immunohistochemistry was performed using Twist and Snail antibodies in 60 ameloblastomas (AMs; 20 solid/multicystic, 20 unicystic, and 20 recurrent), six ameloblastic carcinomas (ACs), 10 adenomatoid odontogenic tumors (AOTs), and six calcifying epithelial odontogenic tumors (CEOTs). A higher rate of tumor cells strongly positive for Twist was observed in AC compared to the other tumors (P = 0.019). The rate of tumor cells strongly positive for Snail tended to be higher in AC than in AM (P = 0.060). AM and AC showed a higher rate of Twist-positive stromal cells than AOT and CEOT (P Tumor cells of recurrent AM showed stronger expression of Twist (P tumor expression of Twist and Snail (r = 0.376, P = 0.001) and between tumor and stromal expression of Snail (r = 0.334, P = 0.002). Twist and Snail may affect the epithelial-mesenchymal transition in AC and be involved in recurrence of AM. Stromal Twist expression may be associated with aggressive clinical behavior of epithelial odontogenic tumors. A Twist-Snail pathway may participate in the development and progression of odontogenic tumors, and tumor-stroma interaction in odontogenic tumors may be mediated by Snail. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Effects of an invasive ant on land snails in the Ogasawara Islands.

    Science.gov (United States)

    Uchida, Shota; Mori, Hideaki; Kojima, Tsubasa; Hayama, Kayo; Sakairi, Yuko; Chiba, Satoshi

    2016-12-01

    We investigated how Pheidole megacephala has affected endemic achatinellid snails because these snails are excellent indicators of the impact of ants and they have high conservation value in Ogasawara. In 2015 we surveyed the Minamizaki area of Hahajima Island of Ogasawara, designated a core zone of the World Heritage Site, for P. megacephala. In Minamizaki, we determined the distribution and density of achatinellid snails in 2015 and compared these data with their distribution and density in 2005. Land cover in the survey area was entirely forest. We also tested whether P. megacephala preyed on achatinellid snails in the laboratory. P. megacephala was present in the forested areas of Minamizaki. Achatinellid snails were absent in 19 of 39 sites where P. megacephala was present, whereas in other areas densities of the snails ranged from 2 to 228 individuals/site. In the laboratory, P. megacephala carried 6 of 7 achatinellid snails and a broken shell was found. Snail distribution and density comparisons and results of the feeding experiments suggest that the presence of P. megacephala has contributed to the decline of achatinellid snails in forests in the survey area. Yet, P. megacephala is not on the official list of invasive non-native species. Stakeholders using the list of invasive species to develop conservation programs should recognize that invasiveness of non-native species differs depending on the ecosystem and that official lists may not be complete. © 2016 Society for Conservation Biology.

  20. TREMATODE INFECTION OF FRESHWATER SNAIL, FAMILY BITHYNIIDAE IN THAILAND.

    Science.gov (United States)

    Kulsantiwong, Jutharat; Prasopdee, Sattrachai; Piratae, Supawadee; Khampoosa, Panita; Thammasiri, Chalida; Suwannatrai, Apiporn; Boonmars, Thidarut; Viyanant, Vithoon; Ruangsitichai, Jiraporn; Tarbsripair, Pairat; Tesana, Smarn

    2015-05-01

    Opisthorchis viverrini is restricted to and requires for its aquatic life cycle only Bithynia snail as first intermediate host but many species of cyprinid fish as second intermediate hosts. A survey in Thailand of trematode infection in freshwater snails of the family Bithyniidae carried out during October 2008 - July 2009 found a total of 5,492 snails, classified into ten species distributed in various geographic areas. Bithyniafuniculata and Gabbia pygmaea were localized to the north, B. s. goniomphalos, Wattebledia siamensis and W. crosseana to northeast and B. s. siamensis, Hydrobioides nassa and G. wykoffi to central region. W. baschi and G. erawanensis was found only in the south and Erawan waterfall, Kanchanaburi Province, respectively. Trematode infection rate was 3.15%. Cercariae were identified as belonging to six types, namely, amartae , monostome, mutabile, O. viverrini, virgulate, and unknown. The prevalence of cercarial infection in B. s. goniomphalos of amartae, mutabile, O. viverrini, virgulate, and unknown type cercaria was 0.55%, 0.74%, 1.07%, 2.87%, and 0.37%, respectively, and in B. s. siamensis monostome (1.10%) and virgulate (0.55%). Only virgulate cercariae were shed from W. crosseana (3.85%) and W. siamensis (5.19%). Cercariae of the unknown type were found in G. wykoffi (1.69%). No infection of O. viverrini cercariae was detected in the other species.

  1. Phenoloxidase activity of Helix aspersa maxima (garden snail, gastropod) hemocyanin.

    Science.gov (United States)

    Raynova, Yuliana; Doumanova, Lyuba; Idakieva, Krassimira Nikolova

    2013-12-01

    The oxygen-transporting protein, hemocyanin (Hc), of the garden snail Helix aspersa maxima (HaH) was isolated and kinetically characterized. Kinetic parameters of the reaction of catalytic oxidation of catechol to quinone, catalyzed by native HaH were determined: the V max value amounted to 22 nmol min(-1) mg(-1), k cat to 1.1 min(-1). Data were compared to those reported for other molluscan Hcs and phenoloxidases (POs). The o-diphenoloxidase activity of the native HaH is about five times higher than the activity determined for the Hcs of the terrestrial snail Helix pomatia and of the marine snail Rapana thomasiana (k cat values of 0.22 and 0.25 min(-1), respectively). The K m values obtained for molluscan Hcs from different species are comparable to those for true POs, but the low catalytic efficiency of Hcs is probably related to inaccessibility of the active sites to potential substrates. Upon treatment of HaH with subtilisin DY, the enzyme activity against substrate catechol was considerably increased. The relatively high proteolytically induced o-diPO activity of HaH allowed using it for preparation of a biosensor for detection of catechol.

  2. 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. 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.

  4. 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

  5. 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...

  6. Snails from heavy-metal polluted environments have reduced sensitivity to carbon dioxide-induced acidity.

    Science.gov (United States)

    Lefcort, Hugh; Cleary, David A; Marble, Aaron M; Phillips, Morgan V; Stoddard, Timothy J; Tuthill, Lara M; Winslow, James R

    2015-01-01

    Anthropogenic atmospheric CO2 reacts with water to form carbonic acid (H2CO3) which increases water acidity. While marine acidification has received recent consideration, less attention has been paid to the effects of atmospheric carbon dioxide on freshwater systems-systems that often have low buffering potential. Since many aquatic systems are already impacted by pollutants such as heavy metals, we wondered about the added effect of rising atmospheric CO2 on freshwater organisms. We studied aquatic pulmonate snails (Physella columbiana) from both a heavy-metal polluted watershed and snails from a reference watershed that has not experienced mining pollution. We used gaseous CO2 to increase water acidity and we then measured changes in antipredatory behavior and also survival. We predicted a simple negative additive effect of low pH. We hypothesized that snails from metal-polluted environments would be physiologically stressed and impaired due to defense responses against heavy metals. Instead, snails from populations that acclimated or evolved in the presence of heavy metal mining pollution were more robust to acidic conditions than were snails from reference habitats. Snails from mining polluted sites seemed to be preadapted to a low pH environment. Their short-term survival in acidic conditions was better than snails from reference sites that lacked metal pollution. In fact, the 48 h survival of snails from polluted sites was so high that it did not significantly differ from the 24 h survival of snails from control sites. This suggests that the response of organisms to a world with rising anthropogenic carbon dioxide levels may be complex and difficult to predict. Snails had a weaker behavioral response to stressful stimuli if kept for 1 month at a pH that differed from their lake of origin. We found that snails raised at a pH of 5.5 had a weaker response (less of a decrease in activity) to concentrated heavy metals than did snails raised at their natal pH of

  7. 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.

  8. 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.

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

    OpenAIRE

    Adrian Toader-Williams; Aurel Şara

    2010-01-01

    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 ...

  10. [Analysis of relationship between natural death of Oncomelania hupensis snails and water level in Eastern Dongting Lake district].

    Science.gov (United States)

    Gao, Jian-chuan; Zhou, Yi-biao; Li, Lin-han; Wu, Jin-yi; Zheng, Sheng-bang; Song, Xiu-xia; He, Zhong; Cai, Bin; You, Jia-bian; Jiang, Qing-wu

    2015-06-01

    To study the reasons of natural death of Oncomelania hupensis snails by comparing the differences of the indicator days covered with water (DCW) in snail marshland and non-snail marshland around the build of Three Gorges Dam in Eastern Dongting Lake areas. Two marshlands were selected, one was a non-snail marshland (Qianliang Lake) and another was a snail marshland (Junshan Park). The measuring points were set through the mechanical sampling. The snails and elevation of the points were surveyed, and the data of the water levels from the hydrological station were collected, and then DCWs were calculated. From 1995 to 2013, DCWs of the marshland of natural death of snails were all more than that of the snail marshland (P snails was more than that after the build of the dam (P = 0.013), and there was the same situation in Junshan Park marshland (P = 0.005). The relationship between snail density and DCW was not significant in Junshan Park marshland (r(s) = 0.008, P = 0.914), and the reference range of DCW of all the measuring points was 76-251 days. In the eastern Dongting Lake district, the build of Three Gorges Dam and DCW may be not the direct factors affecting the natural death of snails and the latter may change the distribution of snails.

  11. Measuring Animal Movements in a Natural Ecosystem: A Mark-Recapture Investigation Using Stream-Dwelling Snails

    Science.gov (United States)

    Stewart, Timothy W.

    2007-01-01

    In this investigation, students measure and describe movements of animals in a natural ecosystem. Students mark stream-dwelling snails with nail polish, then search for these snails 1-7 days later. Distances and directions moved by recaptured snails are recorded. Simple statistical techniques are used to answer specific research questions and…

  12. 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.

  13. Infection with schistosome parasites in snails leads to increased predation by prawns: implications for human schistosomiasis control.

    Science.gov (United States)

    Swartz, Scott J; De Leo, Giulio A; Wood, Chelsea L; Sokolow, Susanne H

    2015-12-01

    Schistosomiasis - a parasitic disease that affects over 200 million people across the globe - is primarily transmitted between human definitive hosts and snail intermediate hosts. To reduce schistosomiasis transmission, some have advocated disrupting the schistosome life cycle through biological control of snails, achieved by boosting the abundance of snails' natural predators. But little is known about the effect of parasitic infection on predator-prey interactions, especially in the case of schistosomiasis. Here, we present the results of laboratory experiments performed on Bulinus truncatus and Biomphalaria glabrata snails to investigate: (i) rates of predation on schistosome-infected versus uninfected snails by a sympatric native river prawn, Macrobrachium vollenhovenii, and (ii) differences in snail behavior (including movement, refuge-seeking and anti-predator behavior) between infected and uninfected snails. In predation trials, prawns showed a preference for consuming snails infected with schistosome larvae. In behavioral trials, infected snails moved less quickly and less often than uninfected snails, and were less likely to avoid predation by exiting the water or hiding under substrate. Although the mechanism by which the parasite alters snail behavior remains unknown, these results provide insight into the effects of parasitic infection on predator-prey dynamics and suggest that boosting natural rates of predation on snails may be a useful strategy for reducing transmission in schistosomiasis hotspots. © 2015. Published by The Company of Biologists Ltd.

  14. Increased response to cadmium and Bacillus thuringiensis maize toxicity in the snail Helix aspersa infected by the nematode Phasmarhabditis hermaphrodita.

    Science.gov (United States)

    Kramarz, Paulina E; de Vaufleury, Annette; Zygmunt, Piotr M S; Verdun, Cyrille

    2007-01-01

    To determine the effect of nematode infection on the response of snails to selected toxins, we infected Helix aspersa with 0-, 0.25-, 1-, or 4-fold the recommended field dose of a commercial nematode application for agricultural use. In the first experiment, the snails also were exposed to cadmium via food and soil at concentrations of 0, 30, 60, 120, or 240 mg/kg in a full-factorial design. In the second experiment, snails were infected with nematodes and also fed either Bt (expressing Bacillus thuringiensis toxin) maize or non-Bt maize. The snails were weighed at the beginning and end (after four weeks) of the experiments, and mortality was checked daily. Neither exposure of snails to nematodes nor exposure of snails to cadmium or Bt toxin affected the survival rates of snails. The number of dead snails was highest for combinations of nematode treatments with cadmium concentrations of 120 and 240 mg/kg. In both experiments (Bt and cadmium), the growth rate decreased with increasing nematode dose. The Bt maize was not harmful to the snails in the absence of nematodes, but infected snails grew faster when fed non-Bt maize. The growth rate of snails exposed to cadmium decreased with exposure to increasing Cd concentrations and differed significantly between the no-nematode treatment and the treatments with nematode doses of one- and fourfold the recommended field dose. Snails treated with the highest dose of nematodes accumulated the highest cadmium concentrations.

  15. Snail Enhances Glycolysis in the Epithelial-Mesenchymal Transition Process by Targeting FBP1 in Gastric Cancer.

    Science.gov (United States)

    Yu, Jie; Li, Jing; Chen, Yong; Cao, Wenmiao; Lu, Yuanyuan; Yang, Jianqi; Xing, Enmin

    2017-01-01

    Snail is a key regulator of epithelial-mesenchymal transition (EMT) in cancer. However, the regulatory role and underlying mechanisms of Snail in gastric cancer metabolism are unknown. In this study, we characterized the regulation of aerobic glycolysis by Snail in gastric cancer. The impact of Snail on glucose metabolism was studied in vitro. Combining maximum standardized uptake value (SUVmax), which was obtained preoperatively via a PET/CT scan, with immunohistochemistry staining, we further analyzed the correlation between SUVmax and Snail expression in gastric cancer tissues. Increased expression of Snail promoted lactate production, glucose utilization, and decreased FBP1 expression at both mRNA and protein level. The expression level of Snail was positively associated with SUVmax in gastric cancer patients (P=0.022). Snail and FBP1 expression were inversely correlated at both mRNA and protein level (P=0.002 and P=0.015 respectively) in gastric cancer tissues. Further studies demonstrated that Snail inhibited the FBP1 gene expression at the transcriptional level. Restoring FBP1 expression reversed the effects of glycolysis and EMT induced by Snail in gastric cancer cells. Our results thus reveal that Snail serves as a positive regulator of glucose metabolism through regulation of the FBP1 in gastric cancer. Disrupting the Snail-FBP1 signaling axis may be effective to prevent primary tumor EMT and glycolysis process. © 2017 The Author(s). Published by S. Karger AG, Basel.

  16. Microbial flora associated with the soils of edible snail farms in ...

    African Journals Online (AJOL)

    Microbial analysis of soil samples collected from snail farms in two different locations (Ughelli, Delta State and Obokofia, Imo State) in southern Nigeria were carried out and compared with that of soil samples collected from ordinary farmlands in these locations.The snail species encountered in this study were Achatina ...

  17. 50 CFR 17.45 - Special rules-snails and clams. [Reserved

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 2 2010-10-01 2010-10-01 false Special rules-snails and clams. 17.45 Section 17.45 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR... Special rules—snails and clams. ...

  18. Studies on the molluscicidal activity of Agave angustifolia and Pittosporum tobira on schistosomiasis transmitting snails.

    Science.gov (United States)

    Ibrahim, Abdalla M; Abdel-Gawad, Mahfouz M; El-Nahas, Hanan A; Osman, Nadia S

    2015-04-01

    In the search for new molluscicidal plants for controlling the snail vectors of schistosomiasis, laboratory evaluation was made to assess the molluscicidal activity of Agave angustifolia and Pittosporum tobira plants against Biomphalaria alexandrina snails. Results indicated that both plants have promising molluscicidal activity as the LC90 of the dry powder of both plants was 120 ppm. Both plants showed marked cercaricidal and miracidicidal potencies against S. mansoni larvae. The LC90 of both plants (120 ppm) killed most B. alexandrina eggs within 24 h of exposure. The sub-lethal concentrations of both plants markedly suppressed the survival rate of B. alexandrina snails and the mortality increased with increasing the concentrations and the exposure period up to 10 successive weeks. The accumulative toxic effect of these concentrations was continuous during the recovery period. Also, the reproductive rates of exposed snails were greatly affected even through the recovery period. This depression in reproductive ability of snails was accompanied by histological damage in the hermaphrodite glands of exposed snails. Meanwhile, the growth of snails was estimated weekly and it showed great inhibition in exposed snails comparing with the control ones.

  19. [Susceptibilities of Oncomelania hupensis snails to Schistosoma japonicum miracidia from different hosts].

    Science.gov (United States)

    Tian, Yue; Wang, Tian-Ping; Wang, Qi-Zhi; Lv, Da-Bing; Yin, Xiao-Mei; Zhou, Li; Wang, Zhen-Li; Wang, Feng-Feng; Wang, Yue; Zhang, Le-Sheng

    2011-08-01

    To understand the susceptibilities of Oncomelania hupensis snails to Schistosoma japonicum miracidia from different hosts. The Schistosoma japonicum eggs from different hosts, such as rabbits, cattle and mice were collected. These eggs were incubated for miracidia, respectively. Each snail from the same site was exposed to 5 miracidia of Schistosoma japonicum from different hosts. The infected snails were fed in the laboratory for two months. Then all the snails were dissected and observed under the dissecting microscope in order to know the infection rate of snails. In the experiment group, the infection rates of snails infected with miracidia from rabbits, cattle and mice were 1.42%, 8.67% and 19.87%, respectively, the mortality rates were 29.5%, 13.5% and 24.5%, respectively. However, the infection rates of snails in the control group were 2.63%, 2.02% and 11.66%, respectively, and the mortality rates were 24.0%, 49.5% and 18.5%, respectively. The susceptibilities of Oncomelania snails to Schistosoma japonicum miracidia from 3 kinds of hosts are significantly different.

  20. 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.

  1. Removal of cadmium from aqueous solution using waste shells of golden apple snail

    Science.gov (United States)

    Benliang Zhao; Jia-en Zhang; Wenbin Yan; Xiaowu Kang; Chaogang Cheng; Ying Ouyang

    2016-01-01

    Golden apple snail (GAS) is one of the 100 worst invasive alien species. With the application of molluscicides to kill and control the spreading of these snails, a large amount of dead GAS shells are remained in many farms. This study ascertained the characteristics and removal of cadmium (Cd) by the GAS shell (GASS) powders and the associate mechanisms....

  2. Analysis of land snail marketing in Owerri agricultural zone of Imo ...

    African Journals Online (AJOL)

    Ten snail marketers were randomly selected from a list of snail marketers compiled for each Market. This gave a total of 70 respondents used for the study. Structured questionnaire was used to collect data, while profitability principle, descriptive statistics and flow chart were employed to analyzing the data. Results showed ...

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

    Science.gov (United States)

    Bdir, Sami; Adwan, Ghaleb

    2011-06-01

    To detect the species of larval trematodes (cercariae) in Melanopsis praemorsa snails from 5 different fresh water bodies in Palestine. 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. 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. These results have been recorded for the first time and these cercariae may be of medical and veterinary importance.

  4. The butterflies and land snails of Ndere Island National Park, Kenya ...

    African Journals Online (AJOL)

    After a survey of Ndere Island National Park between October and November 2004, we recorded 18 species of butterflies and 3 species of land snails. Eurema brigitta brigitta was the most abundant butterfly whereas Thapsia karamwegasensis was the most abundant land snail. Majority of the butterfly species are found in ...

  5. Unpredictable responses of garden snail (Helix aspersa) populations to climate change

    NARCIS (Netherlands)

    Bezemer, T.M.; Knight, K.J.

    2001-01-01

    We studied the impact of climate change on the population dynamics of the garden snail (Helix aspersa) in the Ecotron controlled environment facility. The experimental series ran for three plant generations, allowing the snails to reproduce. We investigated the isolated and combined effects of

  6. Local adaptation of the trematode Fasciola hepatica to the snail Galba truncatula

    Directory of Open Access Journals (Sweden)

    Dreyfuss G.

    2012-08-01

    Full Text Available Experimental infections of six riverbank populations of Galba truncatula with Fasciola hepatica were carried out to determine if the poor susceptibility of these populations to this digenean might be due to the scarcity or the absence of natural encounters between these snails and the parasite. The first three populations originated from banks frequented by cattle in the past (riverbank group whereas the three others were living on islet banks without any known contact with local ruminants (islet group. After their exposure, all snails were placed in their natural habitats from the end of October up to their collection at the beginning of April. Compared to the riverbank group, snails, which died without cercarial shedding clearly predominated in the islet group, while the other infected snails were few in number. Most of these last snails released their cercariae during a single shedding wave. In islet snails dissected after their death, the redial and cercarial burdens were significantly lower than those noted in riverbank G. truncatula. Snails living on these islet banks are thus able to sustain larval development of F. hepatica. The modifications noted in the characteristics of snail infection suggest the existence of an incomplete adaptation between these G. truncatula and the parasite, probably due to the absence of natural contact between host and parasite.

  7. Loss of Snail2 favors skin tumor progression by promoting the recruitment of myeloid progenitors

    DEFF Research Database (Denmark)

    Villarejo, Ana; Molina-Ortiz, Patricia; Montenegro, Yenny

    2015-01-01

    fully reproduces the tumor behavior of the Snail2 null mice and triggers the accumulation of myeloid precursors in the BM, blood and tumor lesions. These results indicate a new role for Snail2 in preventing myeloid precursors recruitment impairing skin chemical carcinogenesis progression....

  8. Effect of feed on the growth rate of African giant land snail ...

    African Journals Online (AJOL)

    The effects of three feed combinations on the growth rate of the African Giant snail, Archachatina marginata, were investigated at the snailery unit of Forestry and Wildlife Department of University of Uyo, Akwa Ibom State, Nigeria. Growth parameters measured included; changes in snail weight, shell length and shell height.

  9. 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.

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

    National Research Council Canada - National Science Library

    Masaki Hoso

    2017-01-01

    .... A remarkable exception is known in the snail-eating snakes of 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...

  11. Land snail species richness in a cocoa agroforest in Ile-Oluji, Ondo ...

    African Journals Online (AJOL)

    The land snail community of an agro-forest in Ile-Oluji, Ondo State, Nigeria, was studied using a combination of direct search and leaf litter sieving techniques. A total of 33 ... The land snail species inventory will increase our knowledge of the molluscan fauna of the forest region and assist in conservation management.

  12. Dinâmica de Lymnaea columella (Say, 1817, hospedeiro intermediário de Fasciola hepatica (Linnaeus, 1758 em municípios do Estado de São Paulo, Brasil

    Directory of Open Access Journals (Sweden)

    Edwin Alberto Pile Maure

    1998-01-01

    Full Text Available A dinâmica populacional de Lymnaea columella na pastagem foi estudada por um período de seis anos em fazendas de exploração leiteira positivas para Fasciola hepatica. A pesquisa foi desenvolvida nos municípios de Piquete e Redenção da Serra, Estado de São Paulo. Os resultados obtidos foram diferentes em cada fazenda, revelando que a dinâmica da população de moluscos está estreitamente relacionada a fatores ecológicos e climáticos. No município de Piquete, o aumento da variação da densidade populacional flutua em relação inversa à temperatura e à pluviosidade, encontrando maior número de moluscos no período seco do ano (maio-outubro. No município de Redenção da Serra, a grande quantidade de matéria orgânica observada no biótopo foi responsável pela captura do maior número de moluscos no período de altas temperaturas e chuvas (janeiro-março.

  13. Land snails as experimental animals: a study of the variability and distribution of individual weights in Helix aspersa snails born from the same clutch

    National Research Council Canada - National Science Library

    Sanz Sampelayo, R; Fonolla, J; Gil Extremera, F

    1990-01-01

    A study was carried out to examine the distribution of individual weights in Helix aspersa snails, the aims being to establish the best estimate of the ponderal growth and also to obtain a model growth curve...

  14. Juveniles of Lymnaea 'smart' snails do not perseverate and have the capacity to form LTM.

    Science.gov (United States)

    Shymansky, Tamila; Protheroe, Amy; Hughes, Emily; Swinton, Cayley; Swinton, Erin; Lukowiak, Kai S; Phillips, Iain; Lukowiak, Ken

    2017-02-01

    Previously, it was concluded that the nervous systems of juvenile snails were not capable of mediating long-term memory (LTM). However, exposure and training of those juvenile snails in the presence of a predator cue significantly altered their ability to learn and form LTM. In addition, there are some strains of Lymnaea which have been identified as 'smart'. These snails form LTM significantly better than the lab-bred strain. Here, we show that juveniles of two smart snail strains not only are capable of associative learning but also have the capacity to form LTM following a single 0.5 h training session. We also show that freshly collected 'wild' 'average' juveniles are also not able to form LTM. Thus, the smart snail phenotype in these strains is expressed in juveniles. © 2017. Published by The Company of Biologists Ltd.

  15. OCCURRENCE OF SALMONELLA, VIBRO AND E. COLI IN EDIBLE LAND SNAIL IN NIGER DELTA, NIGERIA

    Directory of Open Access Journals (Sweden)

    Ime Ebenso

    2012-10-01

    Full Text Available We determined the presence of foodborne pathogens from proximal gut of edible land snail (Archachatina marginata sampled from Itam, Akpan Andem, Afaha and Ikpa markets in Uyo metropolis during the dry season. Fresh snail samples were collected from open market tables presented for sale were screened in the laboratory for microbial load. The total bacteria, Salmonella, Vibrio and Escherichia coli pathogens were measured. The results showed (p<0.05 pathogens in snail meat were found to be above 102cfu-g recommended microbiological limits. The foodborne pathogenic bacteria rating of sampled markets was Itam < Akpan Andem < Afaha < Ikpa. Edible snail can be a bioindicator and vector of foodborne pathogens. It is critical that producers, retailers, processors and consumers take responsibility to prevent contamination, cross-contamination, mishandling, as well as proper holding, storage and cooking of snail meat to eradicate foodborne pathogenic incidence.

  16. Phoresis between the snail Oxytrema (=Elima)carinifera and aquatic insects, especially Rheotanytarsus (Diptera: Chironomidae)

    Energy Technology Data Exchange (ETDEWEB)

    Vinikour, W.S.

    Insects, especially the midge Rheotanytarsus, were found to be phoretically associated with the snail Oxytrema (=Elimia) carinifera. Maximum incidence and density occurred at a shaded headwater site. This association provided the midge with food resources through its filtration of organic matter suspended by the snail. The midge optimized filtration by orientating its tube opening toward the aperture of the snail. This association also provided the midge with a measure of protection from sedimentation, dislodgement, and predation. Rarely, the midge Thienemanniella, the blackfly Simulium tuberosum, and the hydroptilid Ochrotrichia were observed as phoronts of Oxytrema. Their low incidence indicates a nonselective colonization of the snail over other available substrates. Rheotanytarus may be unique among the midges in its preferential phoretic association with snails, especially in less suitable habitats.

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

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    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.

  18. Responses of mud snails from low and high imposex sites to sex pheromones.

    Science.gov (United States)

    Straw, Jessica; Rittschof, Dan

    2004-06-01

    Imposex, male secondary sexual characteristics in female snails, is a morphological indicator of sub-lethal exposure to organotin compounds. The relation between imposex and behavioral responses to sex pheromones was studied. Responses of snails to sex specific pheromones were determined in laboratory assays. Females and males from a low imposex site and females, imposex females and males from a high imposex site were tested. The snails from the low imposex site showed the expected strong behavioral dimorphism with females responding to male pheromone and males responding to female pheromone. In assays using snails from the high imposex site, female and imposex females showed no dimorphism in response to pheromones and males showed a relatively weak dimorphism. As there was no breeding or egg capsule deposition at the high imposex site, we conclude that even the morphologically normal snails were behaviorally and reproductively compromised.

  19. To reduce the global burden of human schistosomiasis, use ‘old fashioned’ snail control

    Science.gov (United States)

    Sokolow, Susanne H.; Wood, Chelsea L.; Jones, Isabel J.; Lafferty, Kevin D.; Kuris, Armand; Hsieh, Michael H.; De Leo, Giulio A.

    2018-01-01

    Control strategies to reduce human schistosomiasis have evolved from ‘snail picking’ campaigns, a century ago, to modern wide-scale human treatment campaigns, or preventive chemotherapy. Unfortunately, despite the rise in preventive chemotherapy campaigns, just as many people suffer from schistosomiasis today as they did 50 years ago. Snail control can complement preventive chemotherapy by reducing the risk of transmission from snails to humans. Here, we present ideas for modernizing and scaling up snail control, including spatiotemporal targeting, environmental diagnostics, better molluscicides, new technologies (e.g., gene drive), and ‘outside the box’ strategies such as natural enemies, traps, and repellants. We conclude that, to achieve the World Health Assembly’s stated goal to eliminate schistosomiasis, it is time to give snail control another look.

  20. 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

    2017-05-01

    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.

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

    Directory of Open Access Journals (Sweden)

    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

  2. Snails and slugs damaging the cut foliage, Cordyline fruticosa and use of biorationals towards their management.

    Science.gov (United States)

    Karthiga, S; Jegathambigai, V; Karunarathne, M D S D; Svinningen, A; Mikunthan, G

    2012-01-01

    Snails and slugs became a serious molluscan pests and damaging leaves of purple compacta, Cordyline fruticosa extensively grown for export at Green Farm Ltd, Sri Lanka. The export quality of leaves of C. fruticosa is lowered due to feeding of snails, Achantina fulica (Bowditch), Opeas pyrgula Schmacker and Boettgerx and Helix aspersa Muller and slugs incurring great loss to cut foliage industry. Paucity of information is available to understand snails and slugs damage and their host range that limits to develop suitable management practices. Therefore this study was aimed to determine damage, alternate hosts and to develop possible management practices. Snails and slugs damaged mainly fresh leaves of C. fruticosa. The severity of damage was 44.5% in infested field based on the visual rating method. Leaves of cassava, sting bean, okra, cucumber, passion fruit, papaya, Glyricidia and shoe flower were identified as alternate hosts and neem, Ixora and Dracaena spp were not served as alternate hosts. Among the plant materials tested for their repellence against snails and slugs revealed that neem seed powder was an irritant; neem leaves, mint leaves and Lantana leaves were acted as anti-feedant and Salt as chemical repellent. Among the barrier and bait experiments Bordeaux mixture exhibited a significant barrier effect against horizontal movement of snails. Baits made out of Metaldehyde bait, vegetables bait and jaggery had a strong effect in repelling the snails and slugs. Mulching with Madhuca longifolia punnac was the best to reduce the snails and slugs population compared to M. longifolia seed kernel powder. Oil from M. longifolia failed to reduce their population. Hence the results revealed that saponin containing M. longifolia punnac helped to eliminate snails and slugs when used as mulch. Metaldehyde, vegetable and jaggery baits are also useful to minimize their colonization further. Hence combination of these methods will help to prevent snails and slugs from

  3. Refuge function of marine algae complicates selection in an intertidal snail.

    Science.gov (United States)

    Kemppainen, Petri; van Nes, Solveig; Ceder, Christofer; Johannesson, Kerstin

    2005-04-01

    Species with restricted gene flow often show trait-shifts from one type of environment to another. In those rock-dwelling marine gastropods that lack larval dispersal, size generally decreases in wave-exposed habitats reducing risk of dislodgement, while increases in less exposed habitats to resist crab-crushing. In Littorina fabalis, however, snails of moderately exposed shores are generally much larger (11-14 mm) than snails of sheltered shores (5-8 mm). Observations from the White Sea (where crabs are not present) indicate that in the absence of crabs snails are small (6-7 mm) in both habitats. We assumed that the optimal size for L. fabalis in the absence of crabs is less than 8 mm, and thus that increased size in moderately exposed habitats in areas with crabs might be a response to crab predation. In a crab-rich area (Sweden) we showed that crab predation is an important mortality factor for this snail species in both sheltered and moderately exposed habitats. In sheltered habitats, snails were relatively more protected from crab-predation when dwelling on their habitual substrate, fucoid algae, than if experimentally tethered to rocks below the algae. This showed that algae function as snail refuges. Snail dislodgement increased, however, with wave exposure but tethering snails in moderately exposed habitats showed that large snails survived equally well on rocks under the algae as in the canopy of the algae. Thus in sheltered habitats a small snail size is favored, probably due to life-history reasons, while increased risk of being dislodged from the algae refuges promotes a large size in moderately exposed habitats. This study shows an example of selection of a trait depends on complex interactions of different factors (life-history optimization, crab predation, wave induced dislodgement and algal refuges).

  4. Changes in frequency of spontaneous oscillations in procerebrum correlate to behavioural choice in terrestrial snails

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    Elena Samarova

    2009-08-01

    Full Text Available The aim of our study was to understand functional significance of spontaneous oscillations of local field potential in the olfactory brain lobe of terrestrial snail, the procerebrum (PC. We compared changes in frequency of oscillations in semi-intact preparations from snails trained to percept the same conditioned odor as positive (associated with food reinforcement or negative (associated with noxious reinforcement. In vivo recordings in freely behaving naïve snails showed a significant decrease of spontaneous PC oscillations frequency during a stage of tentacle withdrawal to odor presentation. In in vitro preparations from naïve snails, a similar decrease in frequency of the PC oscillations to odor presentation was observed. Changes in frequency of the oscillations to cineole presentations in the “aversive” group of snails (demonstrating withdrawal were much more pronounced than in naïve snails. No significant difference in responses to 5 and 20% cineole was noted. Changes in the spontaneous oscillations frequency in the snails trained to respond with positive reaction (approach to cineole depended on the concentration of the applied odor, and these responses were qualitatively similar to responses of other groups during the first 10 s of responses to odor, but significantly different (increase in PC oscillations frequency from the responses of the aversively trained and naïve snails in the interval 11-30 s, which corresponds to the end of the tentacle withdrawal and timing of decision making (approach or escape in the free behaving snails. Obtained results suggest that frequency of the PC lobe spontaneous oscillations correlate to the choice of behavior in snails: withdrawal (decrease in frequency or approach (increase in frequency to the source of odor.

  5. Toxic effects of Cadmium on the garden snail (Helix aspersa)

    Energy Technology Data Exchange (ETDEWEB)

    Russell, L.K. (Northrop Services Inc., Corvallis, OR); DeHaven, J.I.; Botts, R.P.

    1981-05-01

    Spreading treated municipal wastes on agricultural and forest lands is becoming an established method of disposal. However, there is concern about the deleterious effects of toxicants, particularly cadmium, in the sludges. Cadmium concentrations in sewage sludge have been reported as high as 1500 ppM. The work reported here is a part of a larger project to investigate the ecological effects of municipal wastes on forest lands. Snails, Helix aspersa, were chosen to examine the entrance of cadmium into terrestrial food chains. This experiment was designed to determine cadmium accumulation, acute toxicity, and behavioral, reproductive and growth responses with increasing levels of cadmium.

  6. 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. © 2016 SETAC.

  7. 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

  8. 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

  9. 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

  10. THE USE OF Pomacea canaliculata SNAILS IN FEED TO IMPROVE QUALITY OF ALABIO DUCK (Anas plathyrinchos Borneo MEAT

    Directory of Open Access Journals (Sweden)

    A. Subhan

    2016-03-01

    Full Text Available This research was aimed to improve the physical and chemical quality of Alabio ducks which was fed with Pomacea canaliculata snails. Those ducks were raised intensively. There were nine treatments  included R0 (control feed, R1 (control feed + 2.5% Pomacea canaliculata snails from swampy area, R2 (control feed + 5% Pomacea canaliculata snails from swampy area, R3 (control feed + 7.5% Pomacea canaliculata snails from swampy area R4 (control feed + 10% Pomacea canaliculata snails from swampy area R5 (control feed + 2.5% Pomacea canaliculata snails from tidal swampy area, R6 (control feed + 5% Pomacea canaliculata snails from tidal swampy area, R7 (control feed + 7.5% Pomacea canaliculata snails from tidal swampy area, and R8 (control feed + 10% Pomacea canaliculata snails from tidal swampy area. The variables observed included meat chemical and physical quality. A Completely Randomized Design was used in this study. Analysis of variance and Duncan’s multiple range test were used to analyze data. The research results revealed that using Pomacea canaliculata snails in duck feed had a significant effect (P<0.05 towards the physical characteristics (water holding capacity, cooking loss, and tenderness, and chemical characteristics of Alabio duck meat (water, protein, collagen, fat, and cholesterol content. However, there was no significant effect towards meat pH. It can be concluded that using 5% Pomacea canaliculata snails in a mixture of Alabio duck feed decreased cooking loss and meat cholesterol content.

  11. [Effect of land consolidation project on detention of Oncomelania hupensis snails in flood at Yangtze River beach].

    Science.gov (United States)

    Gao, Guang-ting; Liu, Yi-xin; Sun, Zhen; Hu, Jian-guo; Hu, Qiong

    2013-10-01

    To explore the effect of land consolidation project on the detention of Oncomelania hupensis snails in the flood at the Yangtze River beach. The land consolidation project including removing wild willow groves, cutting the high and filling the low, and improving the slope was carried out at the Yangtze River beach in 2011, and the status of snails was investigated before and after the project, respectively, at the end of the flood season. Before the project (2010), at the end of the flood season, the rate of the frames with snails was 96.5% and the snail density was 3.655/0.1 m2. After the project (2012), at the end of the flood season in the same area, the rate of the frames with snails was 2.0% and the snail density was 0.015/0.1 m2 (chi2 = 357.29, P snails in the flood at the Yangtze River beach.

  12. [Relationship between changes of herbaceous plants and Oncomelania hupensis snail distribution under walnut forest of inhibition of snails in mountainous regions of Yunnan Province].

    Science.gov (United States)

    Zhang, Chun-Hua; Liu, Fang-Yan; Liu, Guang-Fu; Sun, Yong-Yu; Tang, Guo-Yong; Li, Kun

    2013-12-01

    To explore the relationship between the changes of herbaceous plants and Oncomelania hupensis snail distribution under the walnut forest of inhibition of snails in mountainous regions of Yunnan Province. The experimental field was established at Sanying Village of Eryuan County, Yunnan Province, where the "Flourishing Forest and Controlling Snails Project" was implemented. The different stand ages (2, 4, 6, 8, 10 years)of walnut forest in experimental groups were selected based on the method of space replacing time, and the non-stocked land was served as a control group. The growth of forest, change of snails, number, biomass, overcast, height of the herbaceous plant and the soil moisture were investigated. The crown closure of 6-year-old walnut forest of inhibition of snails was 0.65. There were 11 species of herbaceous plant belonging to 11 genera, 6 families in 10-year-old forest and its crown closure was 0.77. Compared with the control group, the numbers of families, genera, and species of the 10-year-old forest were decreased by 64.71%, 69.44%, and 77.08%, and the biomass, overcast, and height of it decreased by 12.63%, 19%, and 22.18%, respectively. The soil moisture content (0-20 cm) monthly changes were increased obviously with the increase of stand age. There were no snails besides the control group and 2-year-old walnut forest. Compare with the control group, the occurrence rate of frames with living snails in the 2-year-old walnut forest was decreased by 50%, which was 1.25%. The density of living snails was decreased by 60.16%. The construction of walnut forest of inhibition of snails in mountainous regions of Yunnan Province are suitable for controlling the growth of herbaceous plants and altering the environment of snails. If the coalescence intercropped with crops is carried out, it is not only beneficial to the construction of good ecological environment, but also improves the utilization efficiencies of land, light, and thermal resource, and the

  13. Parasites, sex, and clonal diversity in natural snail populations.

    Science.gov (United States)

    King, Kayla C; Jokela, Jukka; Lively, Curtis M

    2011-05-01

    Under the Red Queen hypothesis, host-parasite coevolution selects against common host genotypes. Although this mechanism might underlie the persistence of sexual reproduction, it might also maintain high clonal diversity. Alternatively, clonal diversity might be maintained by multiple origins of parthenogens from conspecific sexuals, a feature in many animal groups. Herein, we addressed the maintenance of overall genetic diversity by coevolving parasites, as predicted by the Red Queen hypothesis. We specifically examined the contribution of parasites to host clonal diversity and the frequency of sexually reproducing individuals in natural stream populations of Potamopyrgus antipodarum snails. We also tested the alternative hypothesis that clonal diversity is maintained by the input of clones by mutation from sympatric sexuals. Clonal diversity and the frequency of sexual individuals were both positively related to infection frequency. Surprisingly, although clones are derived by mutation from sexual snails, parasites explained more of the genotypic variation among parthenogenetic subpopulations. Our findings thus highlight the importance of parasites as drivers of clonal diversity, as well as sex. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.

  14. 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.

  15. Studies on the Adhesive Property of Snail Adhesive Mucus.

    Science.gov (United States)

    Newar, Janu; Ghatak, Archana

    2015-11-10

    Many gastropod molluscs are known to secrete mucus which allow these animals to adhere to a substrate while foraging over it. While the mucus is known to provide strong adhesion to both dry and wet surfaces, including both horizontal and vertical ones, no systematic study has been carried out to understand the strength of such adhesion under different conditions. We report here results from preliminary studies on adhesion characteristics of the mucus of a snail found in eastern India, Macrochlamys indica. When perturbed, the snail was found to secrete its adhesive mucus, which was collected and subjected to regular adhesion tests. The hydrated mucus was used as such, and also as mixed with buffer of different pH. These experiments suggest that the mucus was slightly alkaline, and showed the maximum adhesion strength of 9 kPa when present in an alkaline buffer. Preliminary studies indicate that adhesive force is related to the ability of the mucus to incorporate water. In alkaline condition, the gel like mass that it forms, incorporate water from a wet surface and enable strong adhesion.

  16. MYCOTOXINS CONTAMINATION IN EDIBLE LAND SNAIL AT GRAZING PADDOCK ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    Ime Ebenso

    2013-02-01

    Full Text Available Mycotoxins contamination of animal products is under reported. Juvenile edible land snails (Archachatina marginata were exposed as sentinels in bottomless metal drums for 1 week at abandoned, new and reference sites respectively at grazing paddock environment, to assess the presence of foodborne microbiological mycotoxins contamination during the dry season. Mycological analysis of A. marginata samples revealed high (p<0.05 contamination at all paddocks ranged from 1.2-1.3 x 105 cfu-g. Results revealed values that were found to be unacceptable by FAO/WHO standards. The presence of Aspergillus niger, A. fumigatus and Penicillum expansum were noted as potential toxicogenic mycoflora. Snails were tolerant to all levels of contamination with no clinical signs of infection or mortality. This finding could serve as basis for assessing pre-slaughter microbial contamination of livestock farm/field environment in order to establish data with comparative epidemiological value, which could highlight early warning signals of food safety risk and cross-contamination of mycotoxins in the food chain.

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

    Science.gov (United States)

    Chontananarth, Thapana; Wongsawad, Chalobol

    2013-03-01

    To investigate the epidemiological situation of cercarial trematodes infection in freshwater snails from different water resources in Chiang Mai province, Thailand. 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. 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%). 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.

  18. [Relationship between Yangtze River floodplain micro ecological environment and distribution of Oncomelania hupensis snails].

    Science.gov (United States)

    Zhao, Jin-song; Wang, An-yun; Zhou, Shu-lin

    2014-04-01

    To explore the relationship between the Yangtze River floodplain ecological environment (vegetation, soil, water and light intensity) and the distribution of Oncomelania hupensis snails, so as to provide the evidence for ecological snail control. Three regions (the Lu-Gang Bridge, Dragon Nest Lake in the bund, and Dragon Nest lake beach) were selected to investigate the plant characteristics (species, height, coverage, frequency and strain of clusters), soil characteristics (temperature, humidity, light intensity) and pH value. All the results were analyzed statistically with SPSS 18 software. A total of 920 boxes were investigated. The vegetation coverage was 3.7%-63.5%, and the dominant population was Cyperusrotundus L. cluster on the marshland. The soil temperature was 19.0 degrees C-24.0 degrees C, pH 5.0-5.7, and humidity 53%-75%. There were statistical significants in average number of living snails and dead snails among 3 groups (P snails were in the back surface in summer and front surface in winter respectively. The average number of living snails was the most near the water. The difference was statistical significant (P snail survival and distribution have close relations with micro ecological environment factors, such as vegetation, soil, water and light intensity.

  19. Snail intermediate host/Schistosoma haematobium relationships from three transmission sites in Benin (West Africa).

    Science.gov (United States)

    Ibikounlé, Moudachirou; Mouahid, Gabriel; Mintsa Nguema, Rodrigue; Sakiti, Nestor; Massougbodji, Achille; Moné, Hélène

    2013-01-01

    The relationships between three strains of Schistosoma haematobium (Doh, Sô-Tchanhoué and Toho-Todougba; from Benin, West Africa) and their snail hosts were assessed by measurement of several life-history traits, including the infection rate; pre-patent period; cercarial production of each parasite strain; and growth, fecundity and survival of the host snails. Adaptations to its local snail host was found for the Toho-Todougba strain and included a short pre-patent period, a long patent period and production of more cercariae in its local snail host. In contrast, the life-history traits of the Doh and Sô-Tchanhoué strains indicated non-local adaptations, as some sympatric host-parasite combinations were not compatible, the highest infection rates occurred in the allopatric snail Bulinus wrighti, and the duration of cercarial production was short because of the high level of mortality of the snails. Furthermore, snail reproduction ceased following infection by each of the three parasite strains, and the life-history traits were not influenced by the miracidial dose.

  20. Kinetic and dynamic aspects of soil-plant-snail transfer of cadmium in the field

    Energy Technology Data Exchange (ETDEWEB)

    Gimbert, Frederic [University of Franche-Comte, Department of Environmental Biology, EA 3184 MR UsC INRA, Place Leclerc, 25030 Besancon Cedex (France); Mench, Michel [UMR BIOGECO INRA 1202, Ecology of Communities, University Bordeaux 1, Avenue des Facultes, 33405 Talence (France); Coeurdassier, Michael; Badot, Pierre-Marie [University of Franche-Comte, Department of Environmental Biology, EA 3184 MR UsC INRA, Place Leclerc, 25030 Besancon Cedex (France); Vaufleury, Annette de [University of Franche-Comte, Department of Environmental Biology, EA 3184 MR UsC INRA, Place Leclerc, 25030 Besancon Cedex (France)], E-mail: annette.devaufleury@univ-fcomte.fr

    2008-04-15

    The proper use of bioaccumulation in the assessment of environmental quality involves accounting for chemical fluxes in organisms. Cadmium (Cd) accumulation kinetics in a soil-plant-snail food chain were therefore investigated in the field under different soil contamination (from 0 to 40 mg kg{sup -1}), soil pH (6 and 7) and season. Allowing for an accurate and sensitive assessment of Cd transfer to snails, toxicokinetics appears an interesting tool in the improvement of risk assessment procedures and a way to quantify metal bioavailability for a defined target. On the basis of uptake fluxes, snails proved to be sensitive enough to distinguish moderate soil contaminations. The soil pH did not appear, in the range studied, as a modulating parameter of the Cd transfer from soil to snail whereas the season, by influencing the snail mass, may modify the internal concentrations. The present data specifying a time integrated assessment of environmental factors on metal bioavailability and transfer to terrestrial snails should ensure their rational use in environmental biomonitoring. - Toxicokinetics and uptake fluxes can be used to describe the environment contamination by Cd, its bioavailability and transfer to Helix aspersa snails in the field.

  1. Male characteristics on female mud snails caused by antifouling bottom paints

    Energy Technology Data Exchange (ETDEWEB)

    Smith, B.S.

    1981-02-01

    This study continues an investigation of an anatomical abnormality, named 'imposex', which consists of a superimposition of male characteristics on to a functionally normal female reproductive anatomy of the dioecious snail Nassarius obsoletus Say. Imposex is prevalent in natural populations living near yacht basins and rarely found distant from them. In the current study caged snails were transferred between a yacht basin and a distant 'clean' locality where the natural population of snails was normal. Imposex was induced in some normal snails kept at the marina and suppressed, but not lost in abnormal snails kept at the clean locality. A similar positive result was obtained in the laboratory by exposing normal snails to organotin-containing antifouling paints and abnormal snails to clean sea water. Results were negative in parallel tests of various marina-associated materials which did not contain organotin. The laboratory studies have thus identified a causative factor for the anatomical abnormalities common near yacht basins in the natural environment. They also provide a rare, if not unique, example of a chemical agent which causes the appearance of superfluous anatomical features in an animal.

  2. Herbivorous snails can increase water clarity by stimulating growth of benthic algae.

    Science.gov (United States)

    Zhang, Xiufeng; Taylor, William D; Rudstam, Lars G

    2017-11-01

    Eutrophication in shallow lakes is characterized by a switch from benthic to pelagic dominance of primary productivity that leads to turbid water, while benthification is characterized by a shift in primary production from the pelagic zone to the benthos associated with clear water. A 12-week mesocosm experiment tested the hypothesis that the herbivorous snail Bellamya aeruginosa stimulates the growth of pelagic algae through grazing on benthic algae and through accelerating nutrient release from sediment. A tube-microcosm experiment using 32P-PO4 as a tracer tested the effects of the snails on the release of sediment phosphorus (P). The mesocosm experiment recorded greater total nitrogen (TN) concentrations and a higher ratio of TN:TP in the overlying water, and a higher light intensity and biomass of benthic algae as measured by chlorophyll a (Chl a) in the snail treatment than in the control. Concentrations of total phosphorus (TP), total suspended solids (TSSs), and inorganic suspended solids (ISSs) in the overlying water were lower in the snail treatment than in the control, though no significant difference in Chl a of pelagic algae between the snail treatment and control was observed. In the microcosm experiment, 32P activity in the overlying water was higher in the snail treatment than in the control, indicating that snails accelerated P release from the sediment. Our interpretation of these results is that snails enhanced growth of benthic algae and thereby improved water clarity despite grazing on the benthic algae and enhancing P release from the sediment. The rehabilitation of native snail populations may therefore enhance the recovery of eutrophic shallow lakes to a clear water state by stimulating growth of benthic algae.

  3. Radix natalensis: the effect of Fasciola hepatica infection on the reproductive activity of the snail

    Science.gov (United States)

    Dar, Yasser; Vignoles, Philippe; Rondelaud, Daniel; Dreyfuss, Gilles

    2014-01-01

    Experimental infections of Egyptian Radix natalensis (shell height at miracidial exposure: 4 mm) with a French isolate of Fasciola hepatica were carried out under laboratory conditions at 22 °C to specify the characteristics and follow the dynamics of their egg-laying. Controls constituted unexposed R. natalensis of the same size. No significant difference between controls and the uninfected snails of the exposed group was noted, whatever the parameter considered. In controls and exposed snails, the dates of the first egg masses were close to each other (56.4–65.3 days). In contrast, the life span of snails and the length of the egg-laying period were significantly shorter and egg production was significantly lower in infected R. natalensis than in controls and uninfected snails. In infected R. natalensis, but without cercarial shedding (NCS snails), egg production was irregular throughout the egg-laying period. In cercarial-shedding (CS) snails, the first egg masses were laid before the first cercarial emergence (at a mean of 56 days and 67 days, respectively). Thereafter, egg mass production of CS snails was irregular up to day 72 of the experiment, stopped during the following two weeks and started again after day 88 for a single snail. In conclusion, the F. hepatica infection of R. natalensis reduced the reproductive activity in both NCS and CS snails. The pattern noted for egg production in infected R. natalensis seems to be species-specific because of the high shell size of this lymnaeid and its role as an atypical intermediate host in the life cycle of the parasite. PMID:24871866

  4. Novel snail1 target proteins in human colon cancer identified by proteomic analysis.

    Directory of Open Access Journals (Sweden)

    María Jesús Larriba

    2010-04-01

    Full Text Available The transcription factor Snail1 induces epithelial-to-mesenchymal transition (EMT, a process responsible for the acquisition of invasiveness during tumorigenesis. Several transcriptomic studies have reported Snail1-regulated genes in different cell types, many of them involved in cell adhesion. However, only a few studies have used proteomics as a tool for the characterization of proteins mediating EMT.We identified by proteomic analysis using 2D-DIGE electrophoresis combined with MALDI-TOF-TOF and ESI-linear ion trap mass spectrometry a number of proteins with variable functions whose expression is modulated by Snail1 in SW480-ADH human colon cancer cells. Validation was performed by Western blot and immunofluorescence analyses. Snail1 repressed several members of the 14-3-3 family of phosphoserine/phosphothreonine binding proteins and also the expression of the Proliferation-associated protein 2G4 (PA2G4 that was mainly localized at the nuclear Cajal bodies. In contrast, the expression of two proteins involved in RNA processing, the Cleavage and polyadenylation specificity factor subunit 6 (CPSF6 and the Splicing factor proline/glutamine-rich (SFPQ, was higher in Snail1-expressing cells than in controls. The regulation of 14-3-3epsilon, 14-3-3tau, 14-3-3zeta and PA2G4 by Snail1 was reproduced in HT29 colon cancer cells. In addition, we found an inverse correlation between 14-3-3sigma and Snail1 expression in human colorectal tumors.We have identified a set of novel Snail1 target proteins in colon cancer that expand the cellular processes affected by Snail1 and thus its relevance for cell function and phenotype.

  5. A distinct lethal neonatal chondrodysplasia with snail-like pelvis: Schneckenbecken dysplasia.

    Science.gov (United States)

    Borochowitz, Z; Jones, K L; Silbey, R; Adomian, G; Lachman, R; Rimoin, D L

    1986-09-01

    We describe the clinical, radiographic, histopathologic, and ultrastructural features of a distinct neonatal lethal chondrodysplasia inherited as an autosomal recessive trait. The characteristic radiographic findings consist of flattened, hypoplastic vertebral bodies; short ribs; hypoplastic iliac bones with "a snail-like" configuration; short, broad long-bones with dumbbell-like appearance; short and wide fibula; and precocious ossification of the tarsus. Chondro-osseous histology is characteristic with hypervascularity, increased cellular density, and normal size chondrocytes with a centrally located round nucleus and absence of lacunar space. Because of the snail-like radiographic appearance of the pelvis in this disorder, we propose the name "Schneckenbecken dysplasia" (ie, German for snail pelvis).

  6. Large-scale facilitation of a sessile community by an invasive habitat-forming snail

    DEFF Research Database (Denmark)

    Thyrring, Jakob; Thomsen, Mads Solgaard; Wernberg, Thomas

    2013-01-01

    Abstract We provide an example of extensive facilitation of a sessile community throughout an invaded estuary by the invasive snail Batillaria australis. We show that B. australis greatly increases a limiting resource (attachment space) to a community of sessile organisms and estimate that a large...... part of the invaded estuary now contain ca. 50 times more sessile individuals associated with the invader than all native snails combined. We argue that native snails are unlikely to have been dramatically reduced by the invader, and we therefore suggest that the shell-attached sessile community...

  7. Spermatheca gland extract of snail (Telescopium telescopium) has wound healing potential: an experimental study in rabbits.

    Science.gov (United States)

    Kumar, Saurabh; Ghosh, Debaki; Biswas, Tuhin Kanti; Dutta, Uttam; Das, Partho; Kundu, Subarna

    2008-12-01

    The effects of spermatheca gland extract of snail (Telescopium telescopium) to promote wound healing were studied in an animal model. The spermatheca gland extract of the snail was used as a topical medicament to treat experimentally created full thickness wounds in 12 rabbits (Oryctologous cuniculus). Wound healing was assessed on the basis of physical, histomorphological, and histochemical changes on days 0, 3, 7, and 14. Statistically significant differences were observed between the groups in all measured parameters. These exciting findings suggest that the data should be further tested in animal models to better understand the potential for wound healing in the spermatheca gland extract of the marine snail.

  8. Effects of Endosulfan on Predator-Prey Interactions Between Catfish and Schistosoma Host Snails.

    Science.gov (United States)

    Monde, Concillia; Syampungani, Stephen; Van den Brink, Paul J

    2016-08-01

    The effect of the pesticide endosulfan on predator-prey interactions between catfish and Schistosoma host snails was assessed in static tank experiments. Hybrid catfish (Clarias gariepinus × C. ngamensis) and Bulinus globosus were subjected to various endosulfan concentrations including an untreated control. The 48- and 96-h LC50 values for catfish were 1.0 and Schistosoma host snails using fish may be affected in endosulfan-polluted aquatic systems of Southern Africa because it has been found present at concentrations that are indicated to cause lethal effects on the evaluated hybrid catfish and to inhibit the predation of snails by this hybrid catfish.

  9. Scientific Opinion on the assessment of the potential establishment of the apple snail in the EU

    OpenAIRE

    EFSA Panel on Plant Health (PLH)

    2013-01-01

    EFSA requested the PLH Panel to review the current state of the art of the biology and ecology of apple snails, reported in this opinion, and to perform an environmental risk assessment for validation of the Plant Health environment guidance document, which will be provided in a second opinion. The Panel presents in this opinion the current state of the art of the biology of apple snails, and develops and uses a population dynamics model to assess the potential establishment of apple snails i...

  10. 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.

  11. The Use of Golden Snail (Pomacea sp.) as Animal Feed in the Philippines

    OpenAIRE

    Serra, AB.

    1997-01-01

    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 ...

  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. Single- or mixed-sex Schistosoma japonicum infections of intermediate host snails in hilly areas of Anhui, China.

    Science.gov (United States)

    Shi, Hui-Ping; Lu, Da-Bing; Shen, Lei; Shi, Tan; Gu, Jian

    2014-02-01

    Schistosomiasis japonicum is one of the most serious communicable diseases, and the transmission of the parasite is dependent of its complex life cycle on which many factors can have an impact. Multiple infections comprising both male and female schistosome within snail intermediate hosts, for example, would facilitate parasite transmission. However, no research on Schistosoma japonicum communities in field-collected Oncomelania hupensis hupensis in relation to schistosome sex has been reported. Therefore, snail survey was performed in a hilly region of Anhui, China, and single- or mixed-sex schistosome infections of snails were detected with final host mouse infection. A total of 8,563 snails were sampled in the field, and 67 were identified with schistosome infections. Of these infected snails, 46 were selected for final host infection. From this, 21 snails were infected with female schistosome, 23 with males and 2 with both males and females. More worms were recovered for snails with mixed-sex infections than with single-sex infection and for snails with male schistosome infection than with female infection (Psnails was significantly higher than would be expected if randomly distributed (Psnails was nearly equal and up to 95.65 % (44/46) of infected snails were single-sex infection. Schistosome infections in snails collected from the hilly area of Anhui Province were not randomly distributed but over-dispersed.

  14. Nuclear expression of Snail1 in borderline and malignant epithelial ovarian tumours is associated with tumour progression

    Directory of Open Access Journals (Sweden)

    Tuhkanen Hanna

    2009-08-01

    Full Text Available Abstract Background Transcription factor Snail1 has a central role in induction of epithelial-mesenchymal transition (EMT. The aim of the present study was to elucidate the expression of Snail1 protein during epithelial ovarian tumourigenesis and to study the association of Snail1 expression with clinicopathological factors and prognosis. Methods Epithelial and stromal fibroblast-like fusiform cells of 14 normal ovarian samples, 21 benign, 24 borderline and 74 malignant epithelial ovarian tumours were studied for Snail1 protein using immunohistochemistry. Results Nuclei of surface peritoneal cells of normal ovaries (n = 14 were regarded as negative for Snail1. Nuclear expression of Snail1 protein in epithelial ovarian tumours was increased during tumour progression from precursor lesions into carcinomas both in epithelial (p = 0.006 and stromal cells (p = 0.007. Nuclei of benign tumours (n = 21 were negative for Snail1. In borderline tumours (n = 24 occasional positive epithelial cells were found in 2 (8% samples and in 3 (13% samples stromal cells were focally positive for Snail1. In carcinomas (n = 74 focal Snail1 staining in epithelial cells was present in 17 (23% tumours, and in stromal cells in 18 (24% tumours. Nuclear expression of Snail1 in epithelial or stromal cells was not associated with clinicopathological factors or prognosis. Conclusion Nuclear Snail1 expression seems to be related to tumour progression, and expression in borderline tumours indicates a role for Snail1 in early epithelial ovarian tumour development. Snail1 also appears to function more generally in tissue remodelling as positive staining was demonstrated in stromal cells.

  15. 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.

  16. Microbiological and Chemical Analysis of Land Snails Commercialised in Sicily.

    Science.gov (United States)

    Cicero, Antonello; Giangrosso, Giuseppe; Cammilleri, Gaetano; Macaluso, Andrea; Currò, Vittoria; Galuppo, Lucia; Vargetto, Daniela; Vicari, Domenico; Ferrantelli, Vincenzo

    2015-05-28

    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.

  17. Associative learning phenomena in the snail (Helix aspersa): conditioned inhibition.

    Science.gov (United States)

    Acebes, Félix; Solar, Patricia; Moris, Joaquín; Loy, Ignacio

    2012-03-01

    Two experiments using garden snails (Helix aspersa) showed conditioned inhibition using both retardation and summation tests. Conditioned inhibition is a procedure by which a stimulus becomes a predictor of the absence of a relevant event--the unconditioned stimulus (US). Typically, conditioned inhibition consists of pairings between an initially neutral conditioned stimulus, CS(2), and an effective excitatory conditioned stimulus, CS(1), in the absence of the US. Retardation and summation tests are required in order to confirm that CS(2) has acquired inhibitory properties. Conditioned inhibition has previously been found in invertebrates; however, these demonstrations did not use the retardation and summation tests required for an unambiguous demonstration of inhibition, allowing for alternative explanations. The implications of our results for the fields of comparative cognition and invertebrate physiological models of learning are discussed.

  18. 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.

  19. THE BIOCIDE TRIBUTYLTIN ALTERS TESTOSTERONE ESTERIFICATION IN MUD SNAILS (ILYANASSA OBSOLETA)

    Science.gov (United States)

    The Biocide Tributyltin Alters Testosterone Esterification in Mud Snails (Ilyanassa obsoleta)Meredith P. Gooding and Gerald A. LeBlanc Department of Environmental and Molecular Toxicology, North Carolina State University, Raleigh, NC 27695-7633Tributyltin (TBT...

  20. Survey of Endangered Tree Snails on Navy-Owned Land in Guam

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The objectives of this survey are to determine the location of Guam tree snails on Navy-owned lands in Guam and to identify the location of suitable habitat and...

  1. 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.

  2. The production of mammalian trematode infective stages by the snail Galba truncatula.

    Science.gov (United States)

    Rondelaud, D; Mouzet, R; Vignoles, P; Dreyfuss, G; Cabaret, J

    2014-03-01

    Several experiments on the breeding of trematode-infected Galba truncatula for obtaining and packaging Fasciola hepatica and Paramphistomum daubneyi metacercariae were carried out to determine the more convenient methods to use for commercial production of these infective stages. Compared to the breeding of infected snails in aquaterraria, the use of 14-cm Petri dishes allowed a greater prevalence of snail infection and a higher number of metacercariae. The production of these larvae was still 2.3-3.4 times greater if infected snails were dissected during the patent period. The aspiration of these metacercariae at the extremity of a Pasteur pipette significantly shortens the time necessary for their transfer from Petri dishes to Eppendorf tubes. Using 14-cm Petri dishes, snail dissection and metacercarial aspiration for their transfer strongly reduce the cost price for metacercarial production of the trematodes Fasciola hepatica and Paramphistomum daubneyi.

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

    National Research Council Canada - National Science Library

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

    2016-01-01

    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...

  4. Wet adhesion and adhesive locomotion of snails on anti-adhesive non-wetting surfaces.

    Directory of Open Access Journals (Sweden)

    Neil J Shirtcliffe

    Full Text Available Creating surfaces capable of resisting liquid-mediated adhesion is extremely difficult due to the strong capillary forces that exist between surfaces. Land snails use this to adhere to and traverse across almost any type of solid surface of any orientation (horizontal, vertical or inverted, texture (smooth, rough or granular or wetting property (hydrophilic or hydrophobic via a layer of mucus. However, the wetting properties that enable snails to generate strong temporary attachment and the effectiveness of this adhesive locomotion on modern super-slippy superhydrophobic surfaces are unclear. Here we report that snail adhesion overcomes a wide range of these microscale and nanoscale topographically structured non-stick surfaces. For the one surface which we found to be snail resistant, we show that the effect is correlated with the wetting response of the surface to a weak surfactant. Our results elucidate some critical wetting factors for the design of anti-adhesive and bio-adhesion resistant surfaces.

  5. Wet adhesion and adhesive locomotion of snails on anti-adhesive non-wetting surfaces.

    Science.gov (United States)

    Shirtcliffe, Neil J; McHale, Glen; Newton, Michael I

    2012-01-01

    Creating surfaces capable of resisting liquid-mediated adhesion is extremely difficult due to the strong capillary forces that exist between surfaces. Land snails use this to adhere to and traverse across almost any type of solid surface of any orientation (horizontal, vertical or inverted), texture (smooth, rough or granular) or wetting property (hydrophilic or hydrophobic) via a layer of mucus. However, the wetting properties that enable snails to generate strong temporary attachment and the effectiveness of this adhesive locomotion on modern super-slippy superhydrophobic surfaces are unclear. Here we report that snail adhesion overcomes a wide range of these microscale and nanoscale topographically structured non-stick surfaces. For the one surface which we found to be snail resistant, we show that the effect is correlated with the wetting response of the surface to a weak surfactant. Our results elucidate some critical wetting factors for the design of anti-adhesive and bio-adhesion resistant surfaces.

  6. Hyperdiverse gene cluster in snail host conveys resistance to human schistosome parasites.

    Directory of Open Access Journals (Sweden)

    Jacob A Tennessen

    2015-03-01

    Full Text Available Schistosomiasis, a neglected global pandemic, may be curtailed by blocking transmission of the parasite via its intermediate hosts, aquatic snails. Elucidating the genetic basis of snail-schistosome interaction is a key to this strategy. Here we map a natural parasite-resistance polymorphism from a Caribbean population of the snail Biomphalaria glabrata. In independent experimental evolution lines, RAD genotyping shows that the same genomic region responds to selection for resistance to the parasite Schistosoma mansoni. A dominant allele in this region conveys an 8-fold decrease in the odds of infection. Fine-mapping and RNA-Seq characterization reveal a 25% haplotypes across the GRC, a significantly non-neutral pattern, suggests that balancing selection maintains diversity at the GRC. Thus, the GRC resembles immune gene complexes seen in other taxa and is likely involved in parasite recognition. The GRC is a potential target for controlling transmission of schistosomiasis, including via genetic manipulation of snails.

  7. Life history studies and habitat requirements of the apple snail at Lake Woodruff National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This study discusses habitat requirements and life history of the apple snail at Lake Woodruff National Wildlife Refuge. A study was initiated during 1971 to gather...

  8. The transcription factor snail controls epithelial-mesenchymal transitions by repressing E-cadherin expression

    DEFF Research Database (Denmark)

    Cano, A; Pérez-Moreno, M A; Rodrigo, I

    2000-01-01

    , occurring concomitantly with the cellular acquisition of migratory properties following downregulation of expression of the adhesion protein E-cadherin. Here we show that mouse Snail is a strong repressor of transcription of the E-cadherin gene. Epithelial cells that ectopically express Snail adopt...... a fibroblastoid phenotype and acquire tumorigenic and invasive properties. Endogenous Snail protein is present in invasive mouse and human carcinoma cell lines and tumours in which E-cadherin expression has been lost. Therefore, the same molecules are used to trigger epithelial-mesenchymal transitions during......The Snail family of transcription factors has previously been implicated in the differentiation of epithelial cells into mesenchymal cells (epithelial-mesenchymal transitions) during embryonic development. Epithelial-mesenchymal transitions are also determinants of the progression of carcinomas...

  9. Behavioural responses of the snail Lymnaea acuminata to carbohydrates and amino acids in bait pellets.

    Science.gov (United States)

    Agrahari, P; Singh, D K

    2010-12-01

    Snail control could play an important role in programmes against fascioliasis, especially if the methods used for molluscicide delivery could be improved, such as by the development of bait formulations containing both an effective attractant and a molluscicide, to ensure good levels of contact between the molluscicide and the target snail populations. In a recent study, the attractiveness to Lymnaea acuminata (an intermediate host of the digenean trematode Fasciola gigantica) of potential components of snail-attractant pellets was investigated. Carbohydrates (glucose, maltose, sucrose or starch, each at 10 mM) and amino acids (citrulline, tryptophan, proline or serine, each at 20 mM), were tested in aquaria, with the snails initially placed 22.5, 30 or 45 cm from an agar pellet containing the component under test. Under these conditions, starch and proline emerged as the strongest attractants for L. acuminata, followed by maltose and serine.

  10. 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...

  11. Mesenchymal cells reactivate Snail1 expression to drive three-dimensional invasion programs

    DEFF Research Database (Denmark)

    Rowe, R.G.; Li, X.Y.; Hu, Y.

    2009-01-01

    Epithelial-mesenchymal transition (EMT) is required for mesodermal differentiation during development. The zinc-finger transcription factor, Snail1, can trigger EMT and is sufficient to transcriptionally reprogram epithelial cells toward a mesenchymal phenotype during neoplasia and fibrosis. Whet...

  12. Preparation and evaluation of appertized from snail Helix aspersa M

    Directory of Open Access Journals (Sweden)

    Nelson Loyola López

    2015-01-01

    Full Text Available This study includes the development and evaluation of snails (Helix aspersa M. appertized, collected at a heliciculture breeding center, located in Los Niches sector, Curico, Maule region, South-central of Chile. The test was conducted at the Laboratory of Sciences of the Catholic University of Maule, Nuestra Señora del Carmen Campus, Curico. The main objective of this work was to study the influence of appertized on sensory attributes and commercial durability of snail Helix aspersa M. Additionally, some specific objectives were proposed as follow: to provide this mollusc with a commercial alternative for it consume, to evaluate its organoleptic characteristics and guarantee the product from both the microbiological and nutritional points of view. Three media cover were used (T0: water + NaCl 2%; T1: Water + NaCl 2% + citric acid 0.5% + kilol and T2: extra virgin olive oil + spices + tocopherol. The product was assessed at two different times, after 30 and 90 days of storage. Two sensory evaluations were conducted to measure various organoleptic attributes and acceptability of the appertized by 14 trained panelists. Amino acid, vitamins, cholesterol, acidity, heavy metals, phosphorus and organochlorines analysis were performed. The presence of both total and fecal contaminant microorganisms was determined. Attributes such as color, flavor, aroma, texture and overall acceptability were also measured. Preserves made by T0 and T1 treatments were equally accepted by the panelists. However, preserve from treatment T2 was rejected because of the detection in them of a very dark color, odor and mealy texture. Positive results regarding the content of amino acids, vitamin C and low cholesterol, as well as the absence of pathogenic microorganisms were obtained for the three treatments.

  13. Lead reduces shell mass in juvenile garden snails (Helix aspersa).

    Science.gov (United States)

    Beeby, Alan; Richmond, Larry; Herpé, Florian

    2002-01-01

    In an earlier paper examining inherited tolerance to Pb, the shell growth of laboratory-bred offspring of Helix aspersa from contaminated sites was compared with that ofjuveniles from naive populations on dosed and undosed diets. Eight-week-old snails were fed either 500 microg g(-1) Pb or a control food in competitive trials between two populations. In the first series of trials, a parental history of exposure to Pb did not confer any advantage to either of two populations (BI and MI) competing with a naïve population (LE). whether Pb was present in the diet or not. However, in the analysis of their metal concentrations reported here, LE are found to retain higher levels of Pb in the soft tissues than either BI or MI. Compared to their siblings on the unleaded diet, dosed LE and BI juveniles had lower soft tissue concentrations of Ca and Mg. Although the growth in shell height is unaffected by diet, LE and BI juveniles build lighter shells on the Pb-dosed diet, achieving around 75% of the shell mass of their controls. In contrast, the shell weights of dosed MI juveniles are depressed by only 15% and show no change in the essential metal concentrations of their soft tissues. A second experiment using five populations fed only the dosed food show that the shell weight/soft tissue weight ratios are comparable to the dosed snails of the previous experiment. Building a lighter shell thus appears to be the common response of all Helix populations to a high Pb diet, at least amongst juveniles. The reduction in its mass means that less Ca and Mg is added to the shell and, along with the lowered soft tissue concentrations observed in some populations. may be a consequence of an increased effort to excrete Pb. The possibility that the MI population shows a genotypic adaptation. perhaps as some form of modification of its Ca metabolism, is briefly discussed.

  14. Bioaccumulative and conchological assessment of heavy metal transfer in a soil-plant-snail food chain

    Directory of Open Access Journals (Sweden)

    Nica Dragos V

    2012-06-01

    Full Text Available Abstract Background Copper (Cu, zinc (Zn, cadmium (Cd, and lead (Pb can pose serious threats to environmental health because they tend to bioaccumulate in terrestrial ecosystems. We investigated under field conditions the transfer of these heavy metals in a soil-plant-snail food chain in Banat area, Romania. The main goal of this paper was to assess the Roman snail (Helix pomatia usefulness in environmental monitoring as bioindicator of heavy metal accumulation. Eight sampling sites, selected by different history of heavy metal (HM exposure, were chosen to be sampled for soil, nettle leaves, and newly matured snails. This study also aimed to identify the putative effects of HM accumulation in the environment on phenotypic variability in selected shell features, which included shell height (SH, relative shell height (RSH, and whorl number (WN. Results Significantly higher amounts of HMs were accumulated in snail hepatopancreas and not in foot. Cu, Zn, and Cd have biomagnified in the snail body, particularly in the hepatopancreas. In contrast, Pb decreased when going up into the food chain. Zn, Cd, and Pb correlated highly with each other at all levels of the investigated food chain. Zn and Pb exhibited an effective soil–plant transfer, whereas in the snail body only foot Cu concentration was correlated with that in soil. There were significant differences among sampling sites for WN, SH, and RSH when compared with reference snails. WN was strongly correlated with Cd and Pb concentrations in nettle leaves but not with Cu and Zn. SH was independent of HM concentrations in soil, snail hepatopancreas, and foot. However, SH correlated negatively with nettle leaves concentrations for each HM except Cu. In contrast, RSH correlated significantly only with Pb concentration in hepatopancreas. Conclusions The snail hepatopancreas accumulates high amounts of HMs, and therefore, this organ can function as a reliable biomarker for tracking HM bioavailability

  15. 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.

  16. 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.

  17. The Effect of Aquatic Plant Abundance on Shell Crushing Resistance in a Freshwater Snail

    Science.gov (United States)

    Chaves-Campos, Johel; Coghill, Lyndon M.; García de León, Francisco J.; Johnson, Steven G.

    2012-01-01

    Most of the shell material in snails is composed of calcium carbonate but the organic shell matrix determines the properties of calcium carbonate crystals. It has been shown that the deposition of calcium carbonate is affected by the ingestion of organic compounds. We hypothesize that organic compounds not synthesized by the snails are important for shell strength and must be obtained from the diet. We tested this idea indirectly by evaluating whether the abundance of the organic matter that snails eat is related to the strength of their shells. We measured shell crushing resistance in the snail Mexipyrgus churinceanus and the abundance of the most common aquatic macrophyte, the water lily Nymphaea ampla, in ten bodies of water in the valley of Cuatro Ciénegas, Mexico. We used stable isotopes to test the assumption that these snails feed on water lily organic matter. We also measured other factors that can affect crushing resistance, such as the density of crushing predators, snail density, water pH, and the concentration of calcium and phosphorus in the water. The isotope analysis suggested that snails assimilate water lily organic matter that is metabolized by sediment bacteria. The variable that best explained the variation in crushing resistance found among sites was the local abundance of water lilies. We propose that the local amount of water lily organic matter provides organic compounds important in shell biomineralization, thus determining crushing resistance. Hence, we propose that a third trophic level could be important in the coevolution of snail defensive traits and predatory structures. PMID:22970206

  18. Cytokines and mother sporocysts in susceptible and resistant Bulinus truncatus snails infected with Schistosoma haematobium.

    Science.gov (United States)

    El-Din, Abdel Hakim Saad; Gawish, Fathiya Ali; Abu El Einin, Hanaa Mohamed; Mansour, Shereen Mahfouz

    2014-08-01

    The presence of immunoreactive interleukin (IL-2), interferon gamma (IFN-γ) and tumor necrosis factor alpha (TNF-α) in addition to the citation of mother sporscytes in cephalopodal musculature in the susceptible and resistance Bulinus truncatus the specific intermediate host for the trematode Schistosoma haematobium were investigated,. Using ELISA tests, Results indicated that the concentration of IL-2-like activity in the susceptible and resistant snails decreased significantly after infection then persisted at low levels until the 4th week post exposure (WPE) in susceptible snails, while in resistant snails elevated during the second WPE, and returned to initial level at 3 and 4 WPE. Susceptible snails had low detectable levels of TNF-α and INF-γ like-activity after infection. However, the resistant snails had significant low levels of TNF-α and INF-γ like-activity from 3 WPE until the 4th WPE without any sign of normalization. Histological sections in the head- foot region of susceptible and resistance B. truncatus infected with S. haematobium, mother sporocysts exists from 1 to 7(day post exposure) DPE, in the susceptible snail the mother sporocysts were found as single, multiple and mature types. No mother sporocysts were appear in the lip and mantle of the snail on 2, 5, 7 DPE and on 1-3, 6 DPE respectively. In the resistant snails few mother sporocysts were found in the lip, mantle and tentacles. The results showed that schistosome-resistant Bulinus can be an alternative strategy for the control of schistosomiasis.

  19. Searching the Human Genome for Snail and Slug With DNA@Home

    OpenAIRE

    Zarns, Kristopher; Desell, Travis; Nechaev, Sergei; Dhasarathy, Archana

    2015-01-01

    DNA@Home is a volunteer computing project that aims to use Gibbs Sampling for the identification and location of DNA control signals on full genome-scale datasets. A fault tolerant and asynchronous implementation of Gibbs sampling using the Berkeley Open Infrastructure for Network Computing (BOINC) was used to identify the location of binding sites of the SNAI1 (Snail) and SNAI2 (Slug) transcription factors across the human genome. Genes regulated by Slug but not Snail, and genes regulated by...

  20. Comparative ORESTES-sampling of transcriptomes of immune-challenged Biomphalaria glabrata snails

    OpenAIRE

    Hanelt, Ben; Lun, Cheng Man; Adema, Coen M.

    2008-01-01

    The snail Biomphalaria glabrata (Gastropoda, Mollusca) is an important intermediate host for the human parasite Schistosoma mansoni (Digenea, Trematoda). Anti-pathogen responses of B. glabrata were studied towards a better understanding of snail immunity and host-parasite compatibility. Open reading frame ESTs (ORESTES) were sampled from different transcriptomes of M line strain B. glabrata, 12 hours post challenge with Escherichia coli (Gram-negative), Micrococcus luteus (Gram-positive) bact...

  1. Mucus trail tracking in a predatory snail: olfactory processing retooled to serve a novel sensory modality

    OpenAIRE

    Patel, Kinjal; Shaheen, Nagma; Witherspoon, Jessica; Robinson, Natallia; Melissa A Harrington

    2013-01-01

    Introduction The rosy wolfsnail (Euglandina rosea), a predatory land snail, finds prey snails and potential mates by following their mucus trails. Euglandina have evolved unique, mobile lip extensions that detect mucus and aid in following trails. Currently, little is known of the neural substrates of the trail-following behavior. Methods To investigate the neural correlates of trail following we used tract-tracing experiments in which nerves were backfilled with either nickel-lysine or Lucif...

  2. Effect of 2450 MHz microwave radiation on the ultrastructure of snail neurons

    Energy Technology Data Exchange (ETDEWEB)

    Arber, S.L.; Neilly, J.P.; Lin, J.C.; Kriho, V.

    1986-01-01

    An electron microscopical study of snail neurons was undertaken to verify whether any ultrastructural alterations accompany microwave-induced electrophysiological changes observed in these neurons. Subesophageal ganglia from Helix aspersa snails were exposed to 2450 MHz microwave radiation in vitro at SAR 12.9 mW/g for 60 minutes. It was found that exposure at 21 degrees C causes minor changes in Golgi complexes and slight swelling of the endoplasmic reticulum.

  3. 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.

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

    Science.gov (United States)

    2011-01-01

    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 snails collected shed schistosome cercariae. Interestingly, the proportion of infected 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

  5. 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.

  6. COMPOSITION OF FAUNA AND DISTRIBUTION OF LAND SNAILS IN INTRAMONTANE DAGESTAN

    Directory of Open Access Journals (Sweden)

    L. J. Harutyunova

    2016-01-01

    Full Text Available Aim. Taxonomy of Caucasian land snails has been studied well enough, but at the same time, the question remains concerning the distribution of some species of snails on the main areas of the Caucasus, especially its eastern part. In this regard, we have set the goal of a more detailed study of the species composition and characteristics of the geographical distribution of land snails of the mountain areas of eastern Caucasus, intramontane Dagestan. Methods. All materials were collected during expeditions of 2011-2015 in the major areas of intramontane Dagestan. We made collections and identified the species according to standard procedures. When determining the species we used common identifiers. Results. As a result of our research we registered, for the territory of intramontane Dagestan, 20 species of land snails belonging to 17 genera of 12 families, among which the most richly repre sented in species diversity can be found the Hygromiidae Tryton family, 1886, which includes in its community 35% of species of land snails of the study area. Conclusion. The findings allow obtaining complete information on the species diversity and characteristics of the geographical distribution of land snails in the intramontane part of Dagestan.

  7. Cloning, isolation, and IgE-binding properties of Helix aspersa (brown garden snail) tropomyosin.

    Science.gov (United States)

    Asturias, Juan A; Eraso, Elena; Arilla, M Carmen; Gómez-Bayón, Nuria; Inácio, Filipe; Martínez, Alberto

    2002-06-01

    Gastropod consumption is quite frequent in the Mediterranean countries and cross-reactivities with crustaceans have been described, but the mechanism of this allergenic cross-reactivity has not been studied in detail. This study aimed to produce recombinant Helix aspersa (brown garden snail) tropomyosin and investigate its implication for cross-reactivity among invertebrates. A tropomyosin-specific cDNA encoding H. aspersa tropomyosin was synthetized, and recombinant allergen was overexpressed in Escherichia coli as nonfusion protein. IgE-binding reactivity was studied by immunoblotting and immunoblot inhibition experiments with sera from snail-allergic patients. Cloned brown garden snail tropomyosin shares high homology with other edible mollusk tropomyosins (84-69% identity) as well as with those from arthropods (65-62%), and less homology with vertebrate ones (56% identity). Tropomyosin reacted with 18% of the sera from patients with snail allergy. Inhibition experiments, using natural and recombinant tropomyosins, showed different degrees of cross-reactivity between invertebrate tropomyosins. Sera from snail-allergic subjects recognized tropomyosins in both mollusks and crustacean extracts. Tropomyosin represents a minor allergen in snail extracts, but it is clearly involved in invertebrate cross-reactivity. Copyright 2002 S. Karger AG, Basel

  8. Effects of dietary exposure to forest pesticides on the brown garden snail Helix aspersa mueller

    Energy Technology Data Exchange (ETDEWEB)

    Schuytema, G.S.; Nebeker, A.V.; Griffis, W.L.

    1994-01-01

    Brown garden snails, Helix aspersa, were fed prepared diets with 12 pesticides used in forest spraying practices where endangered arboreal and terrestrial snails may be at risk. Acephate, atrazine, glyphosate, hexazinone, and picloram were not lethal at concentrations of 5,000 mg/kg in 14-day screening tests. The remaining seven pesticides, lethal to 13-100% of the tested snails at 5,000 mg/kg, were evaluated in 10-day definitive feeding tests. Azinphosmethyl (Guthion) and aminocarb were the most toxic, with 10-day LC50s of 188 and 313 mg/kg, respectively. Paraquat, trichlorfon and fenitrothion had 10-day LC50s of 659, 664, and 7,058 mg/kg respectively. Avoidance of pesticide-containing foods occurred, e.g., 10-day LC50s of >10,000 mg/kg for carbaryl and ethyl parathion. Significant descreases (p<0.05) in snail weight (total, shell-only, body-only) or shell diameter were accompanied by a significant decrease in the amount of food consumed/snail/day. Concentrations of pesticide in tissues were measured in snails exposed to atrazine and azinphosmethyl; there was no bioaccumulation. (Copyright (c) 1994 Springer-Verlag New York Inc.)

  9. Polycomb complex 2 is required for E-cadherin repression by the Snail1 transcription factor

    DEFF Research Database (Denmark)

    Herranz, Nicolás; Pasini, Diego; Díaz, Víctor M

    2008-01-01

    The transcriptional factor Snail1 is a repressor of E-cadherin gene (CDH1) expression essential for triggering epithelial-mesenchymal transition (EMT). Snail1 represses CDH1 directly binding its promoter and inducing the synthesis of Zeb1 repressor. In this article we show that repression of CDH1...... by Snail1, but not by Zeb1, is dependent on the activity of the Polycomb repressive complex 2 (PRC2). ES cells null for Suz12, one of the components of PRC2, show higher levels of Cdh1 mRNA than control ES cells. In tumour cells, interference of PRC2 activity prevents the ability of Snail1 to down......-regulate CDH1 and partially de-represses CDH1. Chromatin immunoprecipitation assays demonstrated that Snail1 increases the binding of Suz12 to CDH1 promoter and the tri-methylation of lysine 27 in the histone 3. Moreover, Snail1 interacts with Suz12 and Ezh2 as shown by coimmunoprecipitation experiments...

  10. 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.

  11. 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.

  12. Snail/Slug binding interactions with YAP/TAZ control skeletal stem cell self-renewal and differentiation.

    Science.gov (United States)

    Tang, Yi; Feinberg, Tamar; Keller, Evan T; Li, Xiao-Yan; Weiss, Stephen J

    2016-09-01

    Bone-marrow-derived skeletal stem/stromal cell (SSC) self-renewal and function are critical to skeletal development, homeostasis and repair. Nevertheless, the mechanisms controlling SSC behaviour, particularly bone formation, remain ill-defined. Using knockout mouse models that target the zinc-finger transcription factors Snail or Slug, or Snail and Slug combined, a regulatory axis has been uncovered wherein Snail and Slug cooperatively control SSC self-renewal, osteoblastogenesis and bone formation. Mechanistically, Snail/Slug regulate SSC function by forming complexes with the transcriptional co-activators YAP and TAZ in tandem with the inhibition of the Hippo-pathway-dependent regulation of YAP/TAZ signalling cascades. In turn, the Snail/Slug-YAP/TAZ axis activates a series of YAP/TAZ/TEAD and Runx2 downstream targets that control SSC homeostasis and osteogenesis. Together, these results demonstrate that SSCs mobilize Snail/Slug-YAP/TAZ complexes to control stem cell function.

  13. [Occurrence of the flagellated protozoan, Cryptobia helicis Leidy, 1846 (Kinetoplasta: Bodonea: Cryptobiidae) in the garden snail, Helix aspersa].

    Science.gov (United States)

    Göçmen, Bayram; Gürelli, Gözde

    2008-01-01

    In this survey, the prevalence and cytological features of the flagellated protozoan, Cryptobia helicis living in the bursa copulatrix of the garden snail, Helix aspersa Müller 1774 found in the vicinity of Izmir, Turkey was investigated. The prevalence of Cryptobia helicis in garden snails collected in the spring of 2005 was found to be 68.65%. This study is the first record of the occurrence of Cryptobia helicis in the garden snail Helix aspersa found in Turkey.

  14. Insights into the evolution of the snail superfamily from metazoan wide molecular phylogenies and expression data in annelids

    Directory of Open Access Journals (Sweden)

    Le Gouar Martine

    2009-05-01

    Full Text Available Abstract Background An important issue concerning the evolution of duplicated genes is to understand why paralogous genes are retained in a genome even though the most likely fate for a redundant duplicated gene is nonfunctionalization and thereby its elimination. Here we study a complex superfamily generated by gene duplications, the snail related genes that play key roles during animal development. We investigate the evolutionary history of these genes by genomic, phylogenetic, and expression data studies. Results We systematically retrieved the full complement of snail related genes in several sequenced genomes. Through phylogenetic analysis, we found that the snail superfamily is composed of three ancestral families, snail, scratchA and scratchB. Analyses of the organization of the encoded proteins point out specific molecular signatures, indicative of functional specificities for Snail, ScratchA and ScratchB proteins. We also report the presence of two snail genes in the annelid Platynereis dumerilii, which have distinct expression patterns in the developing mesoderm, nervous system, and foregut. The combined expression of these two genes is identical to that of two independently duplicated snail genes in another annelid, Capitella spI, but different aspects of the expression patterns are differentially shared among paralogs of Platynereis and Capitella. Conclusion Our study indicates that the snail and scratchB families have expanded through multiple independent gene duplications in the different bilaterian lineages, and highlights potential functional diversifications of Snail and ScratchB proteins following duplications, as, in several instances, paralogous proteins in a given species show different domain organizations. Comparisons of the expression pattern domains of the two Platynereis and Capitella snail paralogs provide evidence for independent subfunctionalization events which have occurred in these two species. We propose that the

  15. Distribution of trematodes in snails in ponds at integrated small-scale aquaculture farms.

    Science.gov (United States)

    Boerlage, Annette S; Graat, Elisabeth A M; Verreth, Johan A; de Jong, Mart C M

    2013-03-01

    In integrated small-scale aquaculture farming, animal and human excreta maybe used as fish feed and pond fertilizer, thereby enhancing transmission of fish-borne zoonotic trematodes (FZTs) from final hosts, like humans, pigs and chickens, to snails. Areas within a pond could vary in trematode egg-load due to the immediate bordering land, and this might provide implications for control of these trematodes or sampling in field studies measuring FZT prevalence in snails. We therefore estimated the effect of bordering land use on prevalence and FZT burden in snails in different areas within small-scale aquaculture ponds. Nine sampling areas within a pond were assigned in six ponds. For each sampling area, about 120 Melanoides tuberculata snails were collected. Based on land use bordering a sampling area, these were categorized in 5 risk-categories: low-risk (road, rice planted in pond, agriculture, or middle of pond), human access point to pond, livestock sty (pigs or poultry), both human access point and livestock sty, and water connection to canal. In total, 5392 snails were collected. Percentages of snails with parapleurolophocercous cercariae varied between 6% in areas categorized as low-risk and areas with livestock sty only to 15% in areas with both human access point and livestock sty; only this 15% was significantly different from the prevalence in the low-risk category. Percentages of snails with xiphidio cercariae did not differ between risk-categories and varied between 5% and 10%. Mean snail size was 15.2mm, and was significantly associated with both the probability of infection as well as parasite burden. Very small differences in parasite burden were found at different land use areas; the maximum difference was about 11 cercariae. This study demonstrated only small differences between areas surrounding a pond on risk of snails to be infected with fish-borne trematodes within different pond areas. In field studies on FZTs in M. tuberculata snails in ponds

  16. Soil parameters are key factors to predict metal bioavailability to snails based on chemical extractant data

    Energy Technology Data Exchange (ETDEWEB)

    Pauget, B.; Gimbert, F., E-mail: frederic.gimbert@univ-fcomte.fr; Scheifler, R.; Coeurdassier, M.; Vaufleury, A. de

    2012-08-01

    Although soil characteristics modulate metal mobility and bioavailability to organisms, they are often ignored in the risk assessment of metal transfer. This paper aims to determine the ability of chemical methods to assess and predict cadmium (Cd), lead (Pb) and zinc (Zn) environmental bioavailability to the land snail Cantareus aspersus. Snails were exposed in the laboratory for 28 days to 17 soils from around a former smelter. The soils were selected for their range of pH, organic matter, clay content, and Cd, Pb and Zn concentrations. The influence of soil properties on environmental availability (estimated using HF-HClO{sub 4}, EDTA, CaCl{sub 2}, NH{sub 4}NO{sub 3}, NaNO{sub 3}, free ion activity and total dissolved metal concentration in soil solution) and on environmental bioavailability (modelled using accumulation kinetics) was identified. Among the seven chemical methods, only the EDTA and the total soil concentration can be used to assess Cd and Pb environmental bioavailability to snails (r Superscript-Two {sub adj} = 0.67 and 0.77, respectively). For Zn, none of the chemical methods were suitable. Taking into account the influence of the soil characteristics (pH and CEC) allows a better prediction of Cd and Pb environmental bioavailability (r Superscript-Two {sub adj} = 0.82 and 0.83, respectively). Even though alone none of the chemical methods tested could assess Zn environmental bioavailability to snails, the addition of pH, iron and aluminium oxides allowed the variation of assimilation fluxes to be predicted. A conceptual and practical method to use soil characteristics for risk assessment is proposed based on these results. We conclude that as yet there is no universal chemical method to predict metal environmental bioavailability to snails, and that the soil factors having the greatest impact depend on the metal considered. - Highlights: Black-Right-Pointing-Pointer New approach to identify chemical methods able to predict metal bioavailability

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

    Science.gov (United States)

    Giannelli, Alessio; Colella, Vito; Abramo, Francesca; do Nascimento Ramos, Rafael Antonio; Falsone, Luigi; Brianti, Emanuele; Varcasia, Antonio; Dantas-Torres, Filipe; Knaus, Martin; Fox, Mark T; Otranto, Domenico

    2015-04-01

    Gastropod-borne parasites may cause debilitating clinical conditions in animals and humans following the consumption of infected intermediate or paratenic hosts. However, the ingestion of fresh vegetables contaminated by snail mucus and/or water has also been proposed as a source of the infection for some zoonotic metastrongyloids (e.g., Angiostrongylus cantonensis). In the meantime, the feline lungworms Aelurostrongylus abstrusus and Troglostrongylus brevior are increasingly spreading among cat populations, along with their gastropod intermediate hosts. The aim of this study was to assess the potential of alternative transmission pathways for A. abstrusus and T. brevior L3 via the mucus of infected Helix aspersa snails and the water where gastropods died. In addition, the histological examination of snail specimens provided information on the larval localization and inflammatory reactions in the intermediate host. Twenty-four specimens of H. aspersa received ~500 L1 of A. abstrusus and T. brevior, and were assigned to six study groups. Snails were subjected to different mechanical and chemical stimuli throughout 20 days in order to elicit the production of mucus. At the end of the study, gastropods were submerged in tap water and the sediment was observed for lungworm larvae for three consecutive days. Finally, snails were artificially digested and recovered larvae were counted and morphologically and molecularly identified. The anatomical localization of A. abstrusus and T. brevior larvae within snail tissues was investigated by histology. L3 were detected in the snail mucus (i.e., 37 A. abstrusus and 19 T. brevior) and in the sediment of submerged specimens (172 A. abstrusus and 39 T. brevior). Following the artificial digestion of H. aspersa snails, a mean number of 127.8 A. abstrusus and 60.3 T. brevior larvae were recovered. The number of snail sections positive for A. abstrusus was higher than those for T. brevior. Results of this study indicate that A

  18. 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

    Full Text Available Gastropod-borne parasites may cause debilitating clinical conditions in animals and humans following the consumption of infected intermediate or paratenic hosts. However, the ingestion of fresh vegetables contaminated by snail mucus and/or water has also been proposed as a source of the infection for some zoonotic metastrongyloids (e.g., Angiostrongylus cantonensis. In the meantime, the feline lungworms Aelurostrongylus abstrusus and Troglostrongylus brevior are increasingly spreading among cat populations, along with their gastropod intermediate hosts. The aim of this study was to assess the potential of alternative transmission pathways for A. abstrusus and T. brevior L3 via the mucus of infected Helix aspersa snails and the water where gastropods died. In addition, the histological examination of snail specimens provided information on the larval localization and inflammatory reactions in the intermediate host.Twenty-four specimens of H. aspersa received ~500 L1 of A. abstrusus and T. brevior, and were assigned to six study groups. Snails were subjected to different mechanical and chemical stimuli throughout 20 days in order to elicit the production of mucus. At the end of the study, gastropods were submerged in tap water and the sediment was observed for lungworm larvae for three consecutive days. Finally, snails were artificially digested and recovered larvae were counted and morphologically and molecularly identified. The anatomical localization of A. abstrusus and T. brevior larvae within snail tissues was investigated by histology. L3 were detected in the snail mucus (i.e., 37 A. abstrusus and 19 T. brevior and in the sediment of submerged specimens (172 A. abstrusus and 39 T. brevior. Following the artificial digestion of H. aspersa snails, a mean number of 127.8 A. abstrusus and 60.3 T. brevior larvae were recovered. The number of snail sections positive for A. abstrusus was higher than those for T. brevior.Results of this study

  19. Release of Lungworm Larvae from Snails in the Environment: Potential for Alternative Transmission Pathways

    Science.gov (United States)

    Giannelli, Alessio; Colella, Vito; Abramo, Francesca; do Nascimento Ramos, Rafael Antonio; Falsone, Luigi; Brianti, Emanuele; Varcasia, Antonio; Dantas-Torres, Filipe; Knaus, Martin; Fox, Mark T.; Otranto, Domenico

    2015-01-01

    Background Gastropod-borne parasites may cause debilitating clinical conditions in animals and humans following the consumption of infected intermediate or paratenic hosts. However, the ingestion of fresh vegetables contaminated by snail mucus and/or water has also been proposed as a source of the infection for some zoonotic metastrongyloids (e.g., Angiostrongylus cantonensis). In the meantime, the feline lungworms Aelurostrongylus abstrusus and Troglostrongylus brevior are increasingly spreading among cat populations, along with their gastropod intermediate hosts. The aim of this study was to assess the potential of alternative transmission pathways for A. abstrusus and T. brevior L3 via the mucus of infected Helix aspersa snails and the water where gastropods died. In addition, the histological examination of snail specimens provided information on the larval localization and inflammatory reactions in the intermediate host. Methodology/Principal Findings Twenty-four specimens of H. aspersa received ~500 L1 of A. abstrusus and T. brevior, and were assigned to six study groups. Snails were subjected to different mechanical and chemical stimuli throughout 20 days in order to elicit the production of mucus. At the end of the study, gastropods were submerged in tap water and the sediment was observed for lungworm larvae for three consecutive days. Finally, snails were artificially digested and recovered larvae were counted and morphologically and molecularly identified. The anatomical localization of A. abstrusus and T. brevior larvae within snail tissues was investigated by histology. L3 were detected in the snail mucus (i.e., 37 A. abstrusus and 19 T. brevior) and in the sediment of submerged specimens (172 A. abstrusus and 39 T. brevior). Following the artificial digestion of H. aspersa snails, a mean number of 127.8 A. abstrusus and 60.3 T. brevior larvae were recovered. The number of snail sections positive for A. abstrusus was higher than those for T. brevior

  20. [Distribution of univalvia molluscs in area with natural decline of Oncomelania hupensis snails in Eastern Dongting Lake area].

    Science.gov (United States)

    Li, Lin-Han; Zhou, Yi-Biao; Zheng, Sheng-Bang; Wu, Jin-Yi; Song, Xiu-Xia; He, Zhong; You, Jia-Bian; Cai, Bin; Zhao, Gen-Ming; Jiang, Qing-Wu

    2014-02-01

    To understand the distribution of univalvia molluscs in Eastern Dongting lake area where the Oncomelania hupensis is extinct, so as to explore the causes of extinction and to provide the evidence for formulating schistosomiasis control strategy. The univalvia molluscs of the Qianliang Lake district, Jianxin District and Junshan Park were investigated in August of 2013. All the collected snails were classified and identified. The data were analyzed by using the method of Shapiro-Wilk normality test and non-parametric test. The ecological biodiversity differences from each district were compared by the biodiversity indexes. The univalvia molluscs collected were from 6 species in 3 families in Gastropoda class, namely Oncomelania hupensis Gredler in Pomatiopsidae family, Parafossarulus striatulus, Alocinma longicornis, Parafossarulus sineasis, Bithynia fuchsisana in Bithyniidae family, and one genus provisioy nally named Radix in Lymaneidae family. In Junshan Park, a total of 4553 snails were collected, among which 1264 were Oncomelania snails. In Jianxin District, 336 univalvia molluscs were collected, and no Oncomelania snails were found. In Qianliang Lake district, there were only 7 Alocinma longicornis snails, 2 Parafossarulus sinensis snails and 1 Parafossarulus striatulus snail collected. There were significant differences among the distributions of the samples from the three districts (chi2 = 166.225, P snails, the species and quantities of other snails become rare in Qianliang Lake area. Whether their causes are relevant is worth further studying.

  1. [Studies on standardization of methods for screening molluscicides in laboratory IV sensitivity of Oncomelania snails from different months to niclosamide].

    Science.gov (United States)

    Li, You-Zi; Xing, Yun-Tian; Li, Hong-Jun; Qu, Guo-Li; Wang, Wei; Wei, Jian-Ying; Liang, You-Sheng; Dai, Jian-Rong

    2012-02-01

    To understand the sensitivity of Oncomelania snails collected from different months to niclosamide, so as to provide the scientific evidence for the standardization of methods for molluscicide screening and efficacy evaluation in laboratory. The snails collected from the marshland of Zhenjiang City, Jiangsu Province month by month from June 2010 to May 2011. After being raised in laboratory for 24 h, the snails were randomly grouped, and then immersed in different concentrations of 50% wettable powder formulation of niclosamide ethanolamine salt at (25 +/- 1) degrees C with a humidity of 60%. The dead snails were identified and counted, and the mortality rate of snails and median lethal concentration (LC50) were calculated. When the snails were immersed in the solutions of niclosamide at concentrations of more than 0.5 mg/L for 24 h, all the snails collected from different months were dead, while 60%-100% of the snail mortality was achieved for 0.250 mg/L niclosamide, 3%-27% for 0.125 mg/L niclosamide, and 3%-20% for 0.062 5 mg/L niclosamide. When the concentration was lower than 0.032 mg/L, the niclosamide was not toxic to the snails within 24 h. The LC50 value was 0.140-0.209 mg/L for 24 h. When the snails were immersed in the solutions of niclosamide at concentrations of more than 0.5 mg/L for 48 h, all the snails collected from different months were dead, while 90%-100% of the snail mortality was achieved for 0.250 mg/L niclosamide, 3%-57% for 0.125 mg/L niclosamide, 3%-13% for 0.062 5 mg/L niclosamide, and 0-10% for 0.032 mg/L niclosamide. When the concentration was lower than 0.016 mg/L, the niclosamide was not toxic to the snails within 48 h. The LC50 value was 0.112-0.170 mg/L for 48 h. There were no significant differences in the mortality of snails caused by niclosamide treatment observed at 24 and 48 h (P values = 0.374 and 0.267, respectively). There are little changes in the sensitivity of snails collected from different months to niclosamide, with

  2. Selenium, copper, and zinc concentrations in the raw and processed meat of edible land snails harvested in Poland

    Directory of Open Access Journals (Sweden)

    Drozd Łukasz

    2017-09-01

    Full Text Available Introduction: The objective of the present research was to carry out a comparative assessment of copper, zinc, and selenium concentrations in the meat of edible land snails collected in Poland (Helix pomatia, Cornu aspersum maxima, and Cornu aspersum aspersum, as well as to determine the effect of preliminary processing of Roman snails (Helix pomatia on the content of the aforementioned elements. Material and Methods: In the first stage, determinations were made on unprocessed snail meat. In the second stage, the study focused on Roman snails and consisted in an additional evaluation of frozen meat after full processing. Zinc and copper contents were determined by flame atomic absorption spectrometry and the selenium content was established by graphite furnace atomic absorption spectrometry. Results: The selenium content differed significantly among all three species. The copper content in Roman snails differed significantly from that in farmed snails. No significant difference in the zinc level was noted among the three snail species. The selenium content in raw and processed meat of Roman snails did not show any significant difference while the copper and zinc level was significantly higher in processed meat samples. Conclusion: The present research on the meat of edible snails showed different levels of selenium, copper, and zinc, depending on the species, collection site, and subjection to processing.

  3. Historical biogeography of the land snail Cornu aspersum: a new scenario inferred from haplotype distribution in the Western Mediterranean basin

    National Research Council Canada - National Science Library

    Guiller, Annie; Madec, Luc

    2010-01-01

    .... We investigated here the phylogeography of this land snail to reassess the evolutionary scenario we previously considered for explaining its scattered distribution in the western Mediterranean...

  4. 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

  5. Lead reduces shell mass in juvenile garden snails (Helix aspersa)

    Energy Technology Data Exchange (ETDEWEB)

    Beeby, Alan; Richmond, Larry; Herpe, Florian

    2002-12-01

    A high Pb diet causes differential depression of juvenile shell mass in populations of Helix. - In an earlier paper examining inherited tolerance to Pb, the shell growth of laboratory-bred offspring of Helix aspersa from contaminated sites was compared with that of juveniles from naieve populations on dosed and undosed diets. Eight-week-old snails were fed either 500 {mu}g g{sup -1} Pb or a control food in competitive trials between two populations. In the first series of trials, a parental history of exposure to Pb did not confer any advantage to either of two populations (BI and MI) competing with a naieve population (LE), whether Pb was present in the diet or not. However, in the analysis of their metal concentrations reported here, LE are found to retain higher levels of Pb in the soft tissues than either BI or MI. Compared to their siblings on the unleaded diet, dosed LE and BI juveniles had lower soft tissue concentrations of Ca and Mg. Although the growth in shell height is unaffected by diet, LE and BI juveniles build lighter shells on the Pb-dosed diet, achieving around 75% of the shell mass of their controls. In contrast, the shell weights of dosed MI juveniles are depressed by only 15% and show no change in the essential metal concentrations of their soft tissues. A second experiment using five populations fed only the dosed food show that the shell weight/soft tissue weight ratios are comparable to the dosed snails of the previous experiment. Building a lighter shell thus appears to be the common response of all Helix populations to a high Pb diet, at least amongst juveniles. The reduction in its mass means that less Ca and Mg is added to the shell and, along with the lowered soft tissue concentrations observed in some populations, may be a consequence of an increased effort to excrete Pb. The possibility that the MI population shows a genotypic adaptation, perhaps as some form of modification of its Ca metabolism, is briefly discussed.

  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. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  7. Discrete movements of foot epithelium during adhesive locomotion of a land snail.

    Science.gov (United States)

    Tyrakowski, Tomasz; Kaczorowski, Piotr; Pawłowicz, Wojciech; Ziółkowski, Marcin; Smuszkiewicz, Piotr; Trojanowska, Iwona; Marszałek, Andrzej; Zebrowska, Małgorzata; Lutowska, Monika; Kopczyńska, Ewa; Lampka, Magdalena; Hołyńska-Iwan, Iga; Piskorska, Elzbieta

    2012-01-01

    During the adhesive locomotion of land snails a series of short dark transverse bands, called pedal or foot waves, is visible ifa moving snail's ventral surface is observed through a sheet of glass. Moreover, the mucus secreted from the pedal glands and some pedal epithelial cells forms a thin layer which acts as a glue augmenting adherence, while also acting as a lubricant under the moving parts of the snail's foot. The relationships between velocity and the frequency of pedal waves as well as changes in the volume of small air bubbles under foot waves were analyzed by means of digital recordings made through a glass sheet on which the snails were moving. On the ventral surface of a moving snail foot, the adhering parts of the foot constituted about 80% of the total area, while several moving parts only about 20%. The single moving region of the foot (the pedal wave) amounted to about 3% of snail length. The epithelium in the region of the pedal wave was arched above the substrate and was also more wrinkled than the stationary epithelium, which enabled the forward motion of each specific point of epithelium during the passage of a pedal wave above it. The actual area of epithelium engaged by a pedal wave was at least 30% greater than the area of the epithelium as recorded through a glass sheet. In the region of the pedal wave, the tiny subepithelial muscles acting on the epithelium move it up in the front part of the wave, and then down at the end of the wave, operating vertically in relation to the substrate. In the middle part of the wave, the epithelium only moves forward. In summary, during the adhesive locomotion of snails, the horizontal movement of the ventral surface epithelium proceeds as temporally separate phases of upward, forward and downward movement.

  8. Population genetics of the Schistosoma snail host Bulinus truncatus in Egypt.

    Science.gov (United States)

    Zein-Eddine, Rima; Djuikwo-Teukeng, Félicité F; Dar, Yasser; Dreyfuss, Gilles; Van den Broeck, Frederik

    2017-08-01

    The tropical freshwater snail Bulinus truncatus serves as an important intermediate host of several human and cattle Schistosoma species in many African regions. Despite some ecological and malacological studies, there is no information on the genetic diversity of B. truncatus in Egypt. Here, we sampled 70-100 snails in ten localities in Upper Egypt and the Nile Delta. Per locality, we sequenced 10 snails at a partial fragment of the cytochrome c oxidase subunit 1 gene (cox1) and we genotyped 25-30 snails at six microsatellite markers. A total of nine mitochondrial haplotypes were detected, of which five were unique to the Nile Delta and three were unique to Upper Egypt, indicating that snail populations may have evolved independently in both regions. Bayesian clustering and hierarchical F-statistics using microsatellite markers further revealed strong population genetic structure at the level of locality. Observed heterozygosity was much lower compared to what is expected under random mating, which could be explained by high selfing rates, population size reductions and to a lesser extent by the Wahlund effect. Despite these observations, we found signatures of gene flow and cross-fertilization, even between snails from the Nile Delta and Upper Egypt, indicating that B. truncatus can travel across large distances in Egypt. These observations could have serious consequences for disease epidemiology, as it means that infected snails from one region could rapidly and unexpectedly spark a new epidemic in another distant region. This could be one of the factors explaining the rebound of human Schistosoma infections in the Nile Delta, despite decades of sustained schistosomiasis control. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Characterization of hemolymph phenoloxidase activity in two Biomphalaria snail species and impact of Schistosoma mansoni infection.

    Science.gov (United States)

    Le Clec'h, Winka; Anderson, Timothy J C; Chevalier, Frédéric D

    2016-01-22

    Biomphalaria snails are the intermediate host of the blood fluke Schistosoma mansoni, which infect more than 67 million people in tropical areas. Phenoloxidase enzymes (POs), including tyrosinases, catecholases, and laccases, are known to play a role in the immune defenses of arthropods, but the PO activity present in Biomphalaria spp. hemolymph has not been characterized. This study was designed to characterize substrate specificity and reaction optima of PO activity in Biomphalaria spp. hemolymph as a starting point to understand the role of this important invertebrate enzyme activity in snail biology and snail-schistosome interactions. We used spectrophotometric assays with 3 specific substrates (L-tyrosine for tyrosinase, L-DOPA for catecholase, and PPD for laccase) and diethylthiocarbarmate (DETC) as specific PO inhibitor to characterize PO activity in the hemolymph of uninfected snails from two Biomphalaria species, and to determine the impact of the parasite Schistosoma mansoni on the PO activity of its B. glabrata vector. We identified laccase activity in hemolymph from uninfected B. glabrata and B. alexandrina. For both species, the activity was optimal at 45 °C and pH 8.5, and located in the plasma. The K m and V max of PO enzymes are 1.45 mM and 0.024 OD.min(-1) for B. glabrata, and 1.19 mM and 0.025 OD.min(-1) for B. alexandrina. When the snail vector is parasitized by S. mansoni, we observed a sharp reduction in laccase activity seven weeks after snail infection. We employed a highly specific spectrophotometric assay using PPD substrate which allows accurate measurement of laccase activity in Biomphalaria spp. hemolymph. We also demonstrated a strong impact of the parasite S. mansoni on laccase activity in the snail host.

  10. 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. © 2014 SETAC.

  11. Toxicity of Metals to a Freshwater Snail, Melanoides tuberculata

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    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.

  12. Antimicrobial Activity of Molluscan Hemocyanins from Helix and Rapana Snails.

    Science.gov (United States)

    Dolashka, Pavlina; Dolashki, Aleksander; Van Beeumen, Jozef; Floetenmeyer, Matthias; Velkova, Lyudmila; Stevanovic, Stefan; Voelter, Wolfgang

    2016-01-01

    For the first time the antimicrobial activities of hemocyanins from the molluscs Rapana venosa (RvH) and Helix aspersa (HaH) have been tested. From the hemolymph of the garden snail H. aspersa one structural subunit (βc-HaH ) and eight functional units (FUs, βc-HaH-a to βc-HaH-h) were isolated, and their N-terminal sequences and molecular weights, ranging between 45 and 65 kDa, determined. The antimicrobial test of the hemocyanins against different bacteria showed that only two FUs from Rapana, RvH1-b and RvH1-e, exhibit a low inhibition effect against Staphylococcus aureus. In contrast and surprisingly, the structural subunit βc-HaH of H. aspersa not only shows strong antimicrobial activities against S. aureus and the likewise Gram-positive Streptococcus epidermidis, but also against the Gram-negative bacterium Escherichia coli. We suggest that this subunit therefore has the potential to become a substitute for the commonly used antibiotics against which bacterial resistance has gradually been developed.

  13. Sensory innervation of the ovotestis in the snail Helix aspersa.

    Science.gov (United States)

    Antkowiak, Tomasz; Chase, Ronald

    2003-11-01

    Because oviposition in the land snail Helix aspersa is a metabolically expensive process coupled to a high fixed cost, one expects oviposition to occur only when the clutch size surpasses a minimum value at which the reproductive benefit exceeds the cost. We propose that neural innervation of the gonad allows H. aspersa to monitor oocyte production and ensure an adequate supply of gametes prior to ovulation. The ovotestis is innervated by a branch of the intestinal nerve in which the majority of axon fibres measure <0.2 microm in diameter. We found a strong positive correlation between the number of mature oocytes in the ovotestis and the frequency of spontaneous afferent spikes in the nerve branch. Tactile stimulation of the ovotestis resulted in a 20-fold increase in afferent spikes and an efferent reflex directed towards the ovotestis and the pericardium. Afferent activity also increased 10-fold after an experimentally induced increase in the volume of the ovotestis. These results suggest that the growing oocytes expand the walls of the acini and trigger action potentials in the mechanosensitive nerve terminals that lie within the acinar walls. We hypothesize that the resulting tonic signal is permissive for ovulation. In addition, a phasic sensory signal may occur during ovulation to trigger CNS motor output related to oviposition.

  14. Methamphetamine enhances memory of operantly conditioned respiratory behavior in the snail Lymnaea stagnalis.

    Science.gov (United States)

    Kennedy, Colin D; Houmes, Stephen W; Wyrick, Katherine L; Kammerzell, Samuel M; Lukowiak, Ken; Sorg, Barbara A

    2010-06-15

    Amphetamines have been used as cognitive enhancers to promote learning and memory. Amphetamines are also drugs of abuse that may promote the initiation of strong memories that ultimately lead to addiction. To understand how methamphetamine (Meth) may be augmenting learning and memory, we chose a relatively simple system, the pond snail, Lymnaea stagnalis. We studied the effects of Meth exposure on the long-term memory (LTM), extinction and reinstatement of operantly conditioned aerial respiratory behavior in Lymnaea. We first determined doses of Meth that would acutely alter respiratory behavior. Next, we measured the impact of training snails in Meth solution or water (control group) using a training procedure that produces LTM (>6 h) in control conditions. Meth exposure impaired the expression of LTM 21 h after two training sessions, but this appeared to be a context-dependent effect only. However, snails exposed to 3.3 mumol l(-1) Meth during training had a decreased rate of extinction of the operantly conditioned memory. We then tested whether this decreased ability of snails to extinguish memory was due to enhanced LTM or impaired extinction of that memory. Snails were operantly conditioned in water and exposed to Meth 16 h after their last trial but 4-5 h prior to extinction. Meth produced an increase rather than a decrease in extinction rate. Thus, Meth impaired extinction only when snails were exposed to Meth during training. Last, we tested the effect of Meth on the ability to form LTM using a single training procedure that is suboptimal for LTM formation. Control snails did not demonstrate LTM, as expected, but pre-exposure of snails to 3.3 micromol l(-1) Meth 24 h prior to the single training session produced LTM 24 h later, indicating that Meth pre-exposure primed snails for LTM formation. Taken together, our studies suggest that LTM is strengthened by Meth such that extinction training is less effective. Lymnaea provides a simple and useful model

  15. Experimental evidence for a new transmission route in a parasitic mite and its mucus-dependent orientation towards the host snail

    OpenAIRE

    SCHÜPBACH, H. U.; BAUR, B.

    2017-01-01

    The route of transmission and host finding behaviour are fundamental components of a parasite's fitness. Riccardoella limacum, a haematophagous mite, lives in the mantle cavity of helicid land snails. To date it has been assumed that this parasitic mite is transmitted during courtship and mating of the host. Here we present experimental evidence for a new transmission route in the host snail Arianta arbustorum. Parasite-free snails were kept on soil on which previously infected host snails ha...

  16. Reproductive Potential of Lola Snail (Trochus niloticus in Saparua Island, Central Maluku

    Directory of Open Access Journals (Sweden)

    HANDY ERWIN PIER LEIMENA

    2006-06-01

    Full Text Available Lola (Trochus niloticus is one of the largest sea snails that lives in the shallow water in Eastern Indonesia and the Pacific. In Saparua Island (Central Maluku, lola population tends to decline due to its exploitation for industrial need. The aim of this study is to determine the reproductive potential of lola snail in Saparua Island, Central Maluku. Lola snails were collected from six locations i.e Booi, Haria, Ullath, Ouw, Itawaka, and Nolloth (03.29o-03.80o LT dan 128.32o-128.43o BT. In each location a strip transect 100 x 2 m was made perpendicular to the coastline started from the lower tide level. Lola snail populations were grouped into different age classes based on the shell diameter using Bhattacharya method. The reproductive potential of lola snail was analyzed by the value of the net reproductive rate. Gonad histology analyses were made by using paraffin methods and stained by Ehrlich’s Haematoxylin-Eosin. The results showed that the net reproductive rate of lola population is 226 individuals and its generation time is 2.88 years. The histological observations showed that the oocyte consist of proliferation, early developing and mature stages.

  17. [Lysozyme activities of Oncomelania hupensis in different seasons and ages of snails].

    Science.gov (United States)

    Huang, Chun-lan; Zhou, Shu-lin; Li, Chao-pin

    2013-10-01

    To explore the relationship between the lysozyme activities of Oncomelania hupensis snails among different seasons, and the difference of the lysozyme activities among the different ages of the snails. The homogenate soft tissues of O. hupensis were dissolved with Tris-HCl-TritonX-114 buffer and concentrated, and the enzyme was extracted by centrifugation. There were significant differences of lysozyme activities among different seasons (Spring, Summer, Autumn, Winter) with the results of 71.33 +/- 4.16 U/mg, 93.67 +/- 7.10 U/mg, 150.33 +/- 10.01 U/mg, 358 +/- 35.38 U/mg,respectively (F = 144.455, P snails) with the results of 93.67 +/- 7.10 U/mg and 69.33 +/- 5.03 U/mg,respectively (t = 4.845, P snails, and the highest lysozyme activity is in winter. The lysozyme activity of adult snails is higher than that of the youth.

  18. NUTRITIONAL VALUE OF CHICKEN OFFAL AS REPLACEMENT FOR LOCAL FISH MEAL IN GROWING SNAILS

    Directory of Open Access Journals (Sweden)

    A OMOLE

    2009-03-01

    Full Text Available A total of ninety six growing snails of mean weight 91.23±2.4g were used to determine the effects of partial or total replacement of local fish meal, a source of protein but expensive to a less expensive, alternative source, chicken offal in the diet of growing snails. Completely randomized design was used for the study. The feeding trial had four treatments, C1, C2, C3 and C4 in which fish meal fraction of the diets was replaced at 0, 50, 75 and 100% with chicken offal respectively. The parameters taken were weight gain, feed intake. Feed conversion ratio, total feed cost, and cost per weight gain were calculated. The trial lasted for twelve weeks. Significant differences were not observed in the mean weekly feed intake of the snails in all the treatments. The mean weight gain in all the treatments were not significantly influenced by the inclusion of chicken offal in the diet (P>0.005. Total feed cost and cost/weight gain reduced as the level of the chicken offal increased while the lowest cost/weight gain was observed in C4. The inclusion of Chicken offal in all the diets had no detrimental effect on the snails in all the treatments. Based on the present results chicken offal could replace local fish meal in the diet of growing snail up to 100% and hereby reduce feed cost

  19. Genetic variation between Biomphalaria alexandrina snails susceptible and resistant to Schistosoma mansoni infection.

    Science.gov (United States)

    El-Nassery, Suzanne M F; Abou-El-Naga, Iman F; Allam, Sonia R; Shaat, Eman A; Mady, Rasha F M

    2013-01-01

    Much effort has been made to control schistosomiasis infection in Egypt. However, enduring effects from such strategies have not yet been achieved. In this study, we sought to determine the genetic variability related to the interaction between Biomphalaria alexandrina snails and Schistosoma mansoni. Using RAPD-PCR with eight (10 mers) random primers, we were able to determine the polymorphic markers that differed between snails susceptible and resistant to Schistosoma mansoni infection using five primers out of the eight. Our results suggest that the RAPD-PCR technique is an efficient means by which to compare genomes and to detect genetic variations between schistosomiasis intermediate hosts. The RAPD technique with the above-noted primers can identify genomic markers that are specifically related to the Biomphalaria alexandrina/Schistosoma mansoni relationship in the absence of specific nucleotide sequence information. This approach could be used in epidemiologic surveys to investigate genetic diversity among Biomphalaria alexandrina snails. The ability to determine resistant markers in Biomphalaria alexandrina snails could potentially lead to further studies that use refractory snails as agents to control the spread of schistosomiasis.

  20. Tales of two snails: sexual selection and sexual conflict in Lymnaea stagnalis and Helix aspersa.

    Science.gov (United States)

    Koene, Joris M

    2006-08-01

    Sexual selection and sexual conflict have been shown to play key roles in the evolution of species with separate sexes. Experimental evidence is accumulating that this is also true for simultaneous hermaphrodites. For example, many species of land snails forcefully stab their mating partners with love darts. In the brown garden snail (Helix aspersa, now called Cantareus asperses), this dart increases sperm storage and paternity, probably via the transfer of an allohormone that inhibits sperm digestion. A recent interspecies comparison of dart-possessing land snails revealed coevolution between darts and spermatophore-receiving organs that is consistent with counteradaptation against an allohormonal manipulation. The great pond snail (Lymnaea stagnalis) seems to use a seminal product to manipulate its partner and mates in the male role when enough seminal fluid is available in the prostate gland. Receipt of semen not only initiates egg laying in virgin animals, but also feminizes the mating partner later in life. These increases in the female function have been shown to go at the expense of growth and seminal fluid production of the sperm recipient. Although in Helix, and probably also Lymnaea, the sperm donor benefits from the induced changes through increased fertilization success, the sperm recipient may experience injury, imposed reallocation of resources, and altered sperm storage. These findings support the existence of sexual conflict in simultaneously hermaphroditic snails, and its importance for the evolution of mating behaviors and reproductive morphologies is discussed.

  1. 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.

  2. 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. Copyright © 2013 Elsevier Inc. All rights reserved.

  3. Polyethyleneimine (PEI mediated siRNA gene silencing in the Schistosoma mansoni snail host, Biomphalaria glabrata.

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    Matty Knight

    2011-07-01

    Full Text Available An in vivo, non-invasive technique for gene silencing by RNA interference (RNAi in the snail, Biomphalaria glabrata, has been developed using cationic polymer polyethyleneimine (PEI mediated delivery of long double-stranded (ds and small interfering (si RNA. Cellular delivery was evaluated and optimized by using a 'mock' fluorescent siRNA. Subsequently, we used the method to suppress expression of Cathepsin B (CathB with either the corresponding siRNA or dsRNA of this transcript. In addition, the knockdown of peroxiredoxin (Prx at both RNA and protein levels was achieved with the PEI-mediated soaking method. B. glabrata is an important snail host for the transmission of the parasitic digenean platyhelminth, Schistosoma mansoni that causes schistosomiasis in the neotropics. Progress is being made to realize the genome sequence of the snail and to uncover gene expression profiles and cellular pathways that enable the snail to either prevent or sustain an infection. Using PEI complexes, a convenient soaking method has been developed, enabling functional gene knockdown studies with either dsRNA or siRNA. The protocol developed offers a first whole organism method for host-parasite gene function studies needed to identify key mechanisms required for parasite development in the snail host, which ultimately are needed as points for disrupting this parasite mediated disease.

  4. 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.

  5. Genetic Variation between Biomphalaria alexandrina Snails Susceptible and Resistant to Schistosoma mansoni Infection

    Directory of Open Access Journals (Sweden)

    Suzanne M. F. El-Nassery

    2013-01-01

    Full Text Available Much effort has been made to control schistosomiasis infection in Egypt. However, enduring effects from such strategies have not yet been achieved. In this study, we sought to determine the genetic variability related to the interaction between Biomphalaria alexandrina snails and Schistosoma mansoni. Using RAPD-PCR with eight (10 mers random primers, we were able to determine the polymorphic markers that differed between snails susceptible and resistant to Schistosoma mansoni infection using five primers out of the eight. Our results suggest that the RAPD-PCR technique is an efficient means by which to compare genomes and to detect genetic variations between schistosomiasis intermediate hosts. The RAPD technique with the above-noted primers can identify genomic markers that are specifically related to the Biomphalaria alexandrina/Schistosoma mansoni relationship in the absence of specific nucleotide sequence information. This approach could be used in epidemiologic surveys to investigate genetic diversity among Biomphalaria alexandrina snails. The ability to determine resistant markers in Biomphalaria alexandrina snails could potentially lead to further studies that use refractory snails as agents to control the spread of schistosomiasis.

  6. 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.

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

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    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.

  8. Characterisation of Reproduction-Associated Genes and Peptides in the Pest Land Snail, Theba pisana.

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    Michael J Stewart

    Full Text Available Increased understanding of the molecular components involved in reproduction may assist in understanding the evolutionary adaptations used by animals, including hermaphrodites, to produce offspring and retain a continuation of their lineage. In this study, we focus on the Mediterranean snail, Theba pisana, a hermaphroditic land snail that has become a highly invasive pest species within agricultural areas throughout the world. Our analysis of T. pisana CNS tissue has revealed gene transcripts encoding molluscan reproduction-associated proteins including APGWamide, gonadotropin-releasing hormone (GnRH and an egg-laying hormone (ELH. ELH isoform 1 (ELH1 is known to be a potent reproductive peptide hormone involved in ovulation and egg-laying in some aquatic molluscs. Two other non-CNS ELH isoforms were also present in T. pisana (Tpi-ELH2 and Tpi-ELH3 within the snail dart sac and mucous glands. Bioactivity of a synthetic ELH1 on sexually mature T. pisana was confirmed through bioassay, with snails showing ELH1-induced egg-laying behaviours, including soil burrowing and oviposition. In summary, this study presents a detailed molecular analysis of reproductive neuropeptide genes in a land snail and provides a foundation for understanding ELH function.

  9. The use of Phytolacca dodecandra berries in the control of trematode-transmitting snails in Zimbabwe.

    Science.gov (United States)

    Ndamba, J; Chandiwana, S K; Makaza, N

    1989-10-01

    Phytolacca dodecandra, a plant with berries of a known molluscicidal potency, was cultivated in Chiweshe. Studies on the snail population density of Bulinus globosus and Lymnaea natalensis as well as schistosome infection rates in the former were carried out in two streams, in one of which a water extract of P. dodecandra berries was applied in late April and May 1987. Snail sampling was carried out twice a month from April 1986 to April 1988, that is for 12 months prior to and after the mollusciciding exercise. B. globosus snails obtained from both streams were examined for infection by cercarial shedding before they were returned to their sites of collection. The 8-h water extract of P. dodecandra was applied to human watercontact points. The two applications were aimed at achieving a concentration of 50 mg/l. No snails were recovered from the experimental sites for a period of 7 months after the mollusciciding exercise. Snails were recovered in the treated sites only after the onset of the rainy season.

  10. Snail/Slug-YAP/TAZ complexes cooperatively regulate mesenchymal stem cell function and bone formation.

    Science.gov (United States)

    Tang, Yi; Weiss, Stephen J

    2017-03-04

    Snail and Slug are zinc-finger transcription factors that play key roles in directing the epithelial-mesenchymal transition (EMT) programs associated with normal development as well as disease progression. More recent work suggests that these EMT-associated transcription factors also modulate the function of both embryonic and adult stem cells. Interestingly, YAP and TAZ, the co-transcriptional effectors of the Hippo pathway, likewise play an important role in stem cell self-renewal and lineage commitment. While direct intersections between the Snail/Slug and Hippo pathways have not been described previously, we recently described an unexpected cooperative interaction between Snail/Slug and YAP/TAZ that controls the self-renewal and differentiation properties of bone marrow-derived mesenchymal stem cells (MSCs), a cell population critical to bone development. Additional studies revealed that both Snail and Slug are able to form binary complexes with either YAP or TAZ that, together, control YAP/TAZ transcriptional activity and function throughout mouse development. Given the more recent observations that MSC-like cell populations are found in association throughout the vasculature where they participate in tissue regeneration, fibrosis and cancer, the Snail/Slug-YAP/TAZ axis is well-positioned to regulate global stem cell function in health and disease.

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

    Science.gov (United States)

    Hoso, Masaki

    2017-01-01

    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. To test this, I compared the morphology and behavior of two sympatric species of Taiwanese snail-eating snakes, Pareas atayal and P. formosensis. 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. 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.

  12. Do ice nucleating agents limit the supercooling ability of the land snail Cornu aspersum?

    Science.gov (United States)

    Ansart, A; Nicolai, A; Vernon, P; Madec, L

    2010-01-01

    The supercooling ability of adults and eggs of the partially freezing tolerant land snail Cornu aspersum remains limited to high subzero temperatures (ca. -5 degree C) whatever the conditions, suggesting the presence of ice nucleating agents (INAs). In this study, we investigated the nucleation activity of the digestive tract of adult snails, eggs and their direct environment: food, faeces and soil. The mucous ribbon always present in the distal intestine of adults exhibited a heat-sensitive (i.e. organic) nucleation activity, close to that of the entire snails during dormant states (aestivation and hibernation). However, a microbial nature of these INAs could not be established in inactive snails. The food provided to active snails contained ice nucleating bacteria, which followed the digestive tract to be found in the intestine and in the faeces, but with a decreasing concentration along the transit. Eggshells also presented a heat-sensitive nucleation activity, which could be related to its structure. Moreover, eggs are laid directly in the soil which contained both organic and mineral INAs. This study is the first to demonstrate the implication of organic INAs in the cold hardiness of a terrestrial gastropod.

  13. Metagonimoides oregonensis (Heterophyidae:Digenea) Infection in pleurocerid snails and Desmognathus quadramaculatus salamander larvae in southern Appalachian streams

    Science.gov (United States)

    Lisa K. Belden; William E. Peterman; Stephen A. Smith; Lauren R. Brooks; E.F. Benfield; Wesley P. Black; Zhaomin Yang; Jeremy M. Wojdak

    2012-01-01

    Metagonimoides oregonensis (Heterophyidae) is a little-known digenetic trematode that uses raccoons and possibly mink as definitive hosts, and stream snails and amphibians as intermediate hosts. Some variation in the life cycle and adult morphology in western and eastern populations has been previously noted. In the southern Appalachians, Pleurocera snails and stream...

  14. Food intake, growth, and reproduction as affected by day length and food availability in the pond snail Lymnaea stagnalis

    NARCIS (Netherlands)

    Maat, ter A.; Zonneveld, C.; Visser, de J.A.G.M.; Jansen, R.F.; Montagne-Wajer, K.; Koene, J.M.

    2007-01-01

    With the aim of integrating the physiology and evolutionary ecology of Lymnaea stagnalis (Linnaeus, 1758), we studied the effects of day length and food availability on the energy budget. Snails were assigned to two different photoperiods and three levels of food availability. The snails were kept

  15. 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...

  16. The potential for using red claw crayfish and hybrid African catfish as biological control agents for Schistosoma host snails

    NARCIS (Netherlands)

    Monde, C.; Syampungani, S.; Rico, A.; Brink, van den P.J.

    2017-01-01

    The potential of red claw crayfish and hybrid African catfish (Clarias gariepinus and Clarias ngamensis) as predators for Schistosoma host snails was evaluated in 2014 by monitoring the consumption of snails by crayfish and catfish in experimental tanks over time under laboratory conditions. After

  17. Common effect of the mucus transferred during mating in two dart-shooting snail species from different families

    NARCIS (Netherlands)

    Kimura, Kazuka; Chiba, Satoshi; Koene, J.M.

    2014-01-01

    Several taxa of pulmonate land snails exhibit a conspicuous mating behaviour, the shooting of so-called love darts. During mating, such land snail species stab a mating partner with a mucus-coated dart. It has previously been shown that the sperm donor physiologically influences the sperm recipient

  18. Performance of broilers fed with snail (Pomacea caniculata meal as substitute to fish meal or meat and bone meal

    Directory of Open Access Journals (Sweden)

    Ulep, LJL.

    1991-01-01

    Full Text Available Snail meal was used as a substitution to fish meat and bone meal in broiler rations. Final weightand feed conversion efficiency of the birds, profit and return on investment differed significantly among treatments. Feed consumption and production costs were comparable. Results show that snail meal can replace fish or meat and bone meal in broiler diets.

  19. Performance of broilers fed with snail (Pomacea caniculata) meal as substitute to fish meal or meat and bone meal

    OpenAIRE

    Ulep, LJL.; Buenafe, MM.

    1991-01-01

    Snail meal was used as a substitution to fish meat and bone meal in broiler rations. Final weightand feed conversion efficiency of the birds, profit and return on investment differed significantly among treatments. Feed consumption and production costs were comparable. Results show that snail meal can replace fish or meat and bone meal in broiler diets.

  20. Shell of snail Helix aspersa maxima (Helicidae) as a protection of bioaccumulation toxic sodium fluoride in soft tissue.

    Science.gov (United States)

    Rać, Monika Ewa; Stachowska, Ewa; Machoy, Zygmunt

    2005-01-01

    The aim of this work was to determine the extent of bioaccumulation of sodium fluorides in tissues of snails under strictly controlled conditions, and also to determine resistance and tolerance to sodium fluoride load in these organisms. The study was performed on snails removed from aestivation. Quantitation of fluoride levels was done in soft tissues (foot, hepatopancreas) and shells of mature snails. Results show that long exposure to sodium fluoride pollution at a low level results in accumulation principally in the soft tissues of the snails. Because of the possibility of fluoride accumulation in the foot, the number of snails used for culinary purposes must be controlled, as it can potentially cause chronic toxemia caused by this trace element. Results also show that the shells of snails offer protection against the bioaccumulation of toxic fluoride in the soft tissue. The Helix aspersa maxima snail is characterised by high resistance and tolerance to fluoride load. Fluoride levels in soft tissues of the snail cannot serve as an indicator for biomonitoring purposes. In contrast, levels in the shell rose significantly with the concentration of fluoride and can be used in biomonitoring of sodium fluoride pollution.

  1. Exploring the effect of drought extent and interval on the Florida snail kite: interplay between spatial and temporal scales

    NARCIS (Netherlands)

    Mooij, W.M.; Bennetts, R.E.; Kitchens, W.M.; DeAngelis, D.L.

    2002-01-01

    The paper aims at exploring the viability of the Florida snail kite population under various drought regimes in its wetland habitat. The population dynamics of snail kites are strongly linked with the hydrology of the system due to the dependence of this bird species on one exclusive prey species,

  2. Analgetic effects of non-thermal GSM-1900 radiofrequency electromagnetic fields in the land snail Helix pomatia.

    Science.gov (United States)

    Nittby, Henrietta; Moghadam, Mehri Kaviani; Sun, Wenjun; Malmgren, Lars; Eberhardt, Jacob; Persson, Bertil R; Salford, Leif G

    2012-03-01

    To investigate whether mobile phone radiation might affect snail nociception, employing radiofrequency (RF) electromagnetic fields (EMF) which, to our knowledge, have hitherto not been studied in a snail model. Exposure to extremely low frequency (ELF) magnetic fields has however been shown to significantly affect nociceptive responses. In the present study, we exposed 29 land snails of the strain Helix pomatia to global system for mobile communications (GSM) EMF at 1900 MHz at the non-thermal level 48 mW/kg for 1 hour each and 29 snails were sham controls. The experiments took place during the onset of summer, with all snails being well out of hibernation. Before and after GSM or sham exposure, the snails were subjected to thermal pain by being placed on a hot plate. The reaction time for retraction from the hot plate was measured by two blinded observers. Comparing the reaction pattern of each snail before and after exposure, the GSM-exposed snails were less sensitive to thermal pain as compared to the sham controls, indicating that RF exposure induces a significant analgesia (Mann-Whitney p < 0.001). This study might support earlier findings, describing beneficial effects of EMF exposure upon nociception.

  3. 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.

  4. Tropomyosin or not tropomyosin, what is the relevant allergen in house dust mite and snail cross allergies?

    Science.gov (United States)

    Bessot, J C; Metz-Favre, C; Rame, J M; De Blay, F; Pauli, G

    2010-02-01

    Since tropomyosin is cross reactive in many arthropods, it was assumed that this highly conserved protein could be responsible for cross reactions in house dust mite (HDM) allergic patients who experienced adverse reactions after crustacean and mollusc ingestion. Here we report two clinical cases where the role of tropomyosin is a matter of debate. In the first case, the clinical history, as well as the results of in vivo and in vitro investigations, are in favour of a shrimp allergy without any snail allergy in a patient sensitized to HDM. In the second, the clinical history and the cutaneous tests are in favour of an allergy to snails without any allergy to shrimps in a patient suffering from HDM allergies. The clinical presentation is different in shrimp and snail allergies. In shrimp allergy, symptoms are mainly urticaria or angio-oedema. In snail allergies, adverse reactions are especially severe asthma. Shrimp tropomyosin is a dominant allergen in crustaceans whereas has a much less prominent role in HDM sensitization. Cross reactivities between HDM and snails have been confirmed by inhibition experiments. However, tropomyosin appears to be a minor allergen or even is not involved in snail allergy. It is necessary to clarify the allergens shared between HDMI and snails. The effects of HDM immunotherapy in snail allergy are questioned. Knowledge of taxonomy can contribute to more precise evaluation of cross reactivities between crustaceans and molluscs.

  5. COMPARATIVE STUDY OF THE MOTHER SPOROCYST OF SCHISTOSOMA MANSONI IN THE SUSCEPTIBLE AND RESISTANT SNAILS OF BIOMPHALARIA GLABRATA

    Directory of Open Access Journals (Sweden)

    I. B. KALHORO, S. JALALI1 AND S. A. SHAMI

    2007-04-01

    Full Text Available The comparative studies of the susceptible and resistant snails of Biomphalaria glabrata mass exposed to miracidia of Schistosoma mansoni were conducted from 1 to10 days post-exposure (DPE. Histological sections of 50 susceptible and 50 resistant snails revealed that many single, multiple, mature and migratory mother sporocysts were observed in the foot, head, lip, tentacle, mantle, anus, buccal mass, neck, kidney, oesophagus, respiratory epithelium of the lung and pericardial cavity of the heart of susceptible snails. Whereas, few single and multiple mother sporocysts were visible in the earlier mentioned first eight organs of the resistant snails throughout infection period. Single mother sporocyst was located in the foot, head, lip and tentacles of susceptible snails at 1-2 DPE. At 3 DPE, multiple mother sporocysts were found in the above organs, and very few of them were observed in the mantle and muscles of the anus of these snails. In the resistant snails, such mother sporocysts were only found in the tentacle and columellar muscles at 9 DPE. At few mother sporocysts reached the buccal mass of the susceptible snails at 4 DPE. Increasing in the number of the single and multiple mother sporocysts were observed in the foot, head and tentacles, whereas a few of them were also visible in the neck and kidney of these snails at 5 DPE. Most of the mother sporocysts grew further in the foot, head, tentacles, mantle and kidney and developed into the mature form at 6 DPE onwards. At 8 DPE, some mature mother sporocysts were observed in the above mentioned organs and oesophagus of these snails. In the foot, head, lip and tentacle at 8 DPE, tegument of mature mother sporocyst was ruptured due to the increase number, and size of the embryos, and a few of them migrated towards the deeper tissues of the organs of the body of the snails. At 9 and 10 DPE, most of the above types of mother sporocyst remained in the earlier mentioned organs, very few were

  6. Molluscicidal effect of nicotinanilide and its intermediate compounds against a freshwater snail Lymnaea luteola, the vector of animal schistosomiasis

    Directory of Open Access Journals (Sweden)

    D Sukumaran

    2004-03-01

    Full Text Available The molluscicidal effect of nicotinanilide was evaluated and compared with niclosamide (2',5-dichloro-4'-nitrosalicylanilide, ethanolamide salt against different stages of the freshwater snail Lymnaea luteola i.e., eggs, immature, young mature, and adults. Calculated values of lethal concentrations (LC50 and LC90 showed that both nicotinanilide and niclosamide as toxic against eggs, immature, and adults. The young mature stage of the snails was comparatively more tolerant to both molluscicides than the other stages. The toxicity of the intermediate compounds of nicotinanilide against the young mature stage of the snails showed them as ineffective. The mortality pattern of the snails exposed to LC90 concentration of these molluscicides showed niclosamide to kill faster (within 8 to 9 h than nicotinanilide (26 to 28 h. In view of the above studies it may be concluded that both molluscicides are toxic against all the stages of the L. luteola snails.

  7. Growth Performance of Pekin Ducks Fed with Golden Snail and Fresh Banana Peelings

    Directory of Open Access Journals (Sweden)

    Ulep, LJL.

    1995-01-01

    Full Text Available The growth performance and economics of feeding confined Pekin ducks with three different levels of golden snail fresh meat and banana peelings in equal percentage for replacing 50 %, 70 % or 90 % of the commercial feed of the diet was studied. Body weight gains and feed consumption of ducks, cost of feed and profit above feed and stock cost different significantly among treatments. Feed conversion varied during the first month of feeding but became comparable after the second month. Ducks fed the diet with 45 % banana peel and 45 % golden snail meat gave the best performance, were the most economical and yielded the highest profit. Snail meat and banana peeling utilization as replacement to commercial diet for ducks is advantageaous in terms of growth performance and cost benefit.

  8. 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

    , paralysis and sensory overload. Most conotoxins target the prey's nervous system but evidence of venom peptides targeting neuroendocrine processes is emerging. Examples include vasopressin, RFamide neuropeptides and recently also insulin. To investigate the diversity of hormone/neuropeptide-like molecules...... 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......, including peptides similar to the bee brain hormone prohormone-4, the mollusc ganglia neuropeptide elevenin, and thyrostimulin, a member of the glycoprotein hormone family, and confirmed the presence of insulin. We confirmed that at least two of these peptides are not only expressed in the venom gland...

  9. Large-scale facilitation of a sessile community by an invasive habitat-forming snail

    Science.gov (United States)

    Thyrring, Jakob; Thomsen, Mads Solgaard; Wernberg, Thomas

    2013-12-01

    We provide an example of extensive facilitation of a sessile community throughout an invaded estuary by the invasive snail Batillaria australis. We show that B. australis greatly increases a limiting resource (attachment space) to a community of sessile organisms and estimate that a large part of the invaded estuary now contain ca. 50 times more sessile individuals associated with the invader than all native snails combined. We argue that native snails are unlikely to have been dramatically reduced by the invader, and we therefore suggest that the shell-attached sessile community, as a functional group, has benefitted significantly from this invasion. These results expand the current understanding of how invaded marine systems respond to habitat-forming invaders.

  10. 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...... richness and schistosomiasis risk. We discuss the limitations of the data and methods used to test the decoy hypothesis for schistosomiasis, and highlight key future research directions that can facilitate more powerful tests of the decoy effect in snail-borne infections, at geographical scales...

  11. Bugs as drugs, part two: worms, leeches, scorpions, snails, ticks, centipedes, and spiders.

    Science.gov (United States)

    Cherniack, E Paul

    2011-03-01

    In this second of a two-part series analyzing the evidence for the use of organisms as medicine, the use of a number of different "bugs" (worms, leeches, snails, ticks, centipedes, and spiders) is detailed. Several live organisms are used as treatments: leeches for plastic surgery and osteoarthritis and the helminths Trichuris suis and Necator americanus for inflammatory bowel disease. Leech saliva is the source of a number of anticoagulants, including the antithrombin agent hirudin and its synthetic analogues, which have been approved for human use. Predatory arthropods, such as certain species of snails, spiders, scorpions, centipedes, and ticks provide a trove of potential analgesic peptides in their venom. A synthetic analogue of a snail venom peptide, ziconotide, has been approved for human use and is used as an alternative to opioids in severe pain cases. Arthropods, such as ticks, have venom that contains anticoagulants and centipede venom has a protein that corrects abnormalities in lipid metabolism.

  12. The potential of snail (Pila leopoldvillensis meal as protein supplement in broiler diets

    Directory of Open Access Journals (Sweden)

    Barcelo, PM.

    1991-01-01

    Full Text Available The chemical analysis revealed that raw golden snail meal (R. GSM had 53.22 %, 6.01 % and 0.49 % crudeprotein, calcium and phosphorus respectively. The cooked golden snail meal (C. GSM had 52.25 % CP, 6.51 % Ca and 0.41 % P. Birds fed with fish meal (control had significantly the highest feed conversion ratio followed by the birds fed the (C. GSM (P 0.05. The gain in weight of the birds fed the (C. GSM had comparable gain in weight with the birds fed the control diet. There were no significant differences observed in a second experiment because the somme feed ingredients had compensated for the deficiency of the nutrients to meet the requirements of the birds. Results reveal that the ingredients of golden snail meal in broiler diets is just as good as incorporating the imported fish meal.

  13. 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.

  14. Physiological, Diurnal and Stress-Related Variability of Cadmium-Metallothionein Gene Expression in Land Snails.

    Directory of Open Access Journals (Sweden)

    Veronika Pedrini-Martha

    Full Text Available The terrestrial Roman snail Helix pomatia has successfully adapted to strongly fluctuating conditions in its natural soil habitat. Part of the snail's stress defense strategy is its ability to express Metallothioneins (MTs. These are multifunctional, cysteine-rich proteins that bind and inactivate transition metal ions (Cd(2+, Zn(2+, Cu(+ with high affinity. In Helix pomatia a Cadmium (Cd-selective, inducible Metallothionein Isoform (CdMT is mainly involved in detoxification of this harmful metal. In addition, the snail CdMT has been shown to also respond to certain physiological stressors. The aim of the present study was to investigate the physiological and diurnal variability of CdMT gene expression in snails exposed to Cd and non-metallic stressors such as desiccation and oxygen depletion. CdMT gene expression was upregulated by Cd exposure and desiccation, whereas no significant impact on the expression of CdMT was measured due to oxygen depletion. Overall, Cd was clearly more effective as an inducer of the CdMT gene expression compared to the applied non-metallic stressors. In unexposed snails, diurnal rhythmicity of CdMT gene expression was observed with higher mRNA concentrations at night compared to daytime. This rhythmicity was severely disrupted in Cd-exposed snails which exhibited highest CdMT gene transcription rates in the morning. Apart from diurnal rhythmicity, feeding activity also had a strong impact on CdMT gene expression. Although underlying mechanisms are not completely understood, it is clear that factors increasing MT expression variability have to be considered when using MT mRNA quantification as a biomarker for environmental stressors.

  15. Experimental Quantification of Long Distance Dispersal Potential of Aquatic Snails in the Gut of Migratory Birds

    Science.gov (United States)

    van Leeuwen, Casper H. A.; van der Velde, Gerard; van Lith, Bart; Klaassen, Marcel

    2012-01-01

    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. PMID:22403642

  16. Physiological, Diurnal and Stress-Related Variability of Cadmium-Metallothionein Gene Expression in Land Snails.

    Science.gov (United States)

    Pedrini-Martha, Veronika; Niederwanger, Michael; Kopp, Renate; Schnegg, Raimund; Dallinger, Reinhard

    2016-01-01

    The terrestrial Roman snail Helix pomatia has successfully adapted to strongly fluctuating conditions in its natural soil habitat. Part of the snail's stress defense strategy is its ability to express Metallothioneins (MTs). These are multifunctional, cysteine-rich proteins that bind and inactivate transition metal ions (Cd(2+), Zn(2+), Cu(+)) with high affinity. In Helix pomatia a Cadmium (Cd)-selective, inducible Metallothionein Isoform (CdMT) is mainly involved in detoxification of this harmful metal. In addition, the snail CdMT has been shown to also respond to certain physiological stressors. The aim of the present study was to investigate the physiological and diurnal variability of CdMT gene expression in snails exposed to Cd and non-metallic stressors such as desiccation and oxygen depletion. CdMT gene expression was upregulated by Cd exposure and desiccation, whereas no significant impact on the expression of CdMT was measured due to oxygen depletion. Overall, Cd was clearly more effective as an inducer of the CdMT gene expression compared to the applied non-metallic stressors. In unexposed snails, diurnal rhythmicity of CdMT gene expression was observed with higher mRNA concentrations at night compared to daytime. This rhythmicity was severely disrupted in Cd-exposed snails which exhibited highest CdMT gene transcription rates in the morning. Apart from diurnal rhythmicity, feeding activity also had a strong impact on CdMT gene expression. Although underlying mechanisms are not completely understood, it is clear that factors increasing MT expression variability have to be considered when using MT mRNA quantification as a biomarker for environmental stressors.

  17. Differential Spatial Repositioning of Activated Genes in Biomphalaria glabrata Snails Infected with Schistosoma mansoni

    Science.gov (United States)

    Arican-Goktas, Halime D.; Ittiprasert, Wannaporn; Bridger, Joanna M.; Knight, Matty

    2014-01-01

    Schistosomiasis is an infectious disease infecting mammals as the definitive host and fresh water snails as the intermediate host. Understanding the molecular and biochemical relationship between the causative schistosome parasite and its hosts will be key to understanding and ultimately treating and/or eradicating the disease. There is increasing evidence that pathogens that have co-evolved with their hosts can manipulate their hosts' behaviour at various levels to augment an infection. Bacteria, for example, can induce beneficial chromatin remodelling of the host genome. We have previously shown in vitro that Biomphalaria glabrata embryonic cells co-cultured with schistosome miracidia display genes changing their nuclear location and becoming up-regulated. This also happens in vivo in live intact snails, where early exposure to miracidia also elicits non-random repositioning of genes. We reveal differences in the nuclear repositioning between the response of parasite susceptible snails as compared to resistant snails and with normal or live, attenuated parasites. Interestingly, the stress response gene heat shock protein (Hsp) 70 is only repositioned and then up-regulated in susceptible snails with the normal parasite. This movement and change in gene expression seems to be controlled by the parasite. Other differences in the behaviour of genes support the view that some genes are responding to tissue damage, for example the ferritin genes move and are up-regulated whether the snails are either susceptible or resistant and upon exposure to either normal or attenuated parasite. This is the first time host genome reorganisation has been seen in a parasitic host and only the second time for any pathogen. We believe that the parasite elicits a spatio-epigenetic reorganisation of the host genome to induce favourable gene expression for itself and this might represent a fundamental mechanism present in the human host infected with schistosome cercariae as well as in

  18. Second intermediate host land snails and definitive host animals of Brachylaima cribbi in southern Australia

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    Butcher A.R.

    2005-03-01

    Full Text Available This study of infection of southern Australian land snails with Brachylaima cribbi metacercariae has shown that all commonly encountered native and introduced snails are susceptible second intermediate hosts. The range of infected snails is extensive with metacercariae-infected snails being present in all districts across southern Australia. C. virgata has the highest average natural metacercarial infection intensity of 6.1 metacercariae per infected snail. The susceptibility of birds, mammals and reptiles to B. cribbi infection was studied in South Australia by capturing, dissecting and examining the intestinal tract contents of animals which commonly eat land snails as a food source. Indigenous Australian little ravens (Corvus mellori, which are a common scavenger bird, and two other passeriform birds, the black bird (Turdus merula and the starling (Sturnus vulgaris, which are both introduced European birds, were found to have the highest infection rates of all animals examined. Other birds found infected with B. cribbi were an emu (Dromaius novaehollandiae, chickens (Gallus gallus and a pigeon (Columba livia. Natural infections were also detected in field mice (Mus domesticus and shingleback lizards (Tiliqua rugosa although the intensity of infection was lower than that observed in birds. Susceptibility studies of laboratory mice, rats and ducks showed that mice developed patent infections which persisted for several weeks, rats developed a short-lived infection of three weeks’ duration and ducks did not support infection. This study has shown for the first time that a brachylaimid can infect a wide host range of birds, mammals and reptiles in nature.

  19. 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

    Abstract 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. PMID:28769723

  20. Mucus trail tracking in a predatory snail: olfactory processing retooled to serve a novel sensory modality.

    Science.gov (United States)

    Patel, Kinjal; Shaheen, Nagma; Witherspoon, Jessica; Robinson, Natallia; Harrington, Melissa A

    2014-01-01

    The rosy wolfsnail (Euglandina rosea), a predatory land snail, finds prey snails and potential mates by following their mucus trails. Euglandina have evolved unique, mobile lip extensions that detect mucus and aid in following trails. Currently, little is known of the neural substrates of the trail-following behavior. To investigate the neural correlates of trail following we used tract-tracing experiments in which nerves were backfilled with either nickel-lysine or Lucifer yellow, extracellular recording of spiking neurons in snail procerebra using a multielectrode array, and behavioral assays of trail following and movement toward the source of a conditioned odor. The tract-tracing experiments demonstrate that in Euglandina, the nerves carrying mucus signals innervate the same region of the central ganglia as the olfactory nerves, while the electrophysiology studies show that mucus stimulation of the sensory epithelium on the lip extensions alters the frequency and pattern of neural activity in the procerebrum in a manner similar to odor stimulation of the olfactory epithelium on the optic tentacles of another land snail species, Cantareus aspersa (previously known as Helix aspersa). While Euglandina learn to follow trails of novel chemicals that they contact with their lip extensions in one to three trials, these snails proved remarkably resistant to associative learning in the olfactory modality. Even after seven to nine pairings of odorant molecules with food, they showed no orientation toward the conditioned odor. This is in marked contrast to Cantareus snails, which reliably oriented toward conditioned odors after two to three trials. The apparent inability of Euglandina to learn to associate food with odors and use odor cues to drive behavior suggests that the capability for sophisticated neural processing of nonvolatile mucus cues detected by the lip extensions has evolved at the expense of processing of odorant molecules detected by the olfactory system.

  1. Predator-induced morphological plasticity across local populations of a freshwater snail.

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    Christer Brönmark

    Full Text Available The expression of anti-predator adaptations may vary on a spatial scale, favouring traits that are advantageous in a given predation regime. Besides, evolution of different developmental strategies depends to a large extent on the grain of the environment and may result in locally canalized adaptations or, alternatively, the evolution of phenotypic plasticity as different predation regimes may vary across habitats. We investigated the potential for predator-driven variability in shell morphology in a freshwater snail, Radix balthica, and whether found differences were a specialized ecotype adaptation or a result of phenotypic plasticity. Shell shape was quantified in snails from geographically separated pond populations with and without molluscivorous fish. Subsequently, in a common garden experiment we investigated reaction norms of snails from populations' with/without fish when exposed to chemical cues from tench (Tinca tinca, a molluscivorous fish. We found that snails from fish-free ponds had a narrow shell with a well developed spire, whereas snails that coexisted with fish had more rotund shells with a low spire, a shell morphology known to increase survival rate from shell-crushing predators. The common garden experiment mirrored the results from the field survey and showed that snails had similar reaction norms in response to chemical predator cues, i.e. the expression of shell shape was independent of population origin. Finally, we found significant differences for the trait means among populations, within each pond category (fish/fish free, suggesting a genetic component in the determination of shell morphology that has evolved independently across ponds.

  2. Seasonal modulation of free radical metabolism in estivating land snails Helix aspersa.

    Science.gov (United States)

    Ramos-Vasconcelos, Gabriella R; Cardoso, Luciano A; Hermes-Lima, Marcelo

    2005-02-01

    We investigated the regulation of free radical metabolism in Helix aspersa snails during a cycle of 20-day estivation and 24-h arousal in summer in comparison with estivation/arousal in winter-snails. In winter-snails (J. Exp. Biol. 206, 675-685, 2003), we had already observed an increase in the selenium-dependent glutathione-peroxidase (Se-GPX) activity in foot muscle and hepatopancreas and in the contents of hepatopancreas GSH-equivalents (GSH-eq=GSH+2 GSSG) during estivation compared with 24-h aroused snails. Summer-estivation prompted a 3.6-fold increase in Se-GPX activity in hepatopancreas, though not in foot muscle. Total-superoxide dismutase and catalase activities in hepatopancreas decreased (by 30-40%) during summer-estivation; however, no changes occurred in the activities of glutathione reductase, glutathione S-transferase and glucose-6-phosphate dehydrogenase in the two organs. GSH-eq levels were increased (by 54%) in foot muscle during estivation, but were unchanged in hepatopancreas. In contrast with winter-snails, oxidative stress markers (lipid peroxidation, carbonyl protein, and the GSSG/GSH-eq ratio) were unaltered during estivation/arousal in summer. These results demonstrate that seasonality modulates not only the absolute activities/levels of antioxidants (enzymes and GSH-eq) in H. aspersa, but also the regulatory process that controls the snail's antioxidant capacity during estivation/arousal. These results suggest that H. aspersa has an "internal clock" controlling the regulation of free radical metabolism in the different seasons.

  3. Mucus trail tracking in a predatory snail: olfactory processing retooled to serve a novel sensory modality

    Science.gov (United States)

    Patel, Kinjal; Shaheen, Nagma; Witherspoon, Jessica; Robinson, Natallia; Harrington, Melissa A

    2014-01-01

    Introduction The rosy wolfsnail (Euglandina rosea), a predatory land snail, finds prey snails and potential mates by following their mucus trails. Euglandina have evolved unique, mobile lip extensions that detect mucus and aid in following trails. Currently, little is known of the neural substrates of the trail-following behavior. Methods To investigate the neural correlates of trail following we used tract-tracing experiments in which nerves were backfilled with either nickel-lysine or Lucifer yellow, extracellular recording of spiking neurons in snail procerebra using a multielectrode array, and behavioral assays of trail following and movement toward the source of a conditioned odor. Results The tract-tracing experiments demonstrate that in Euglandina, the nerves carrying mucus signals innervate the same region of the central ganglia as the olfactory nerves, while the electrophysiology studies show that mucus stimulation of the sensory epithelium on the lip extensions alters the frequency and pattern of neural activity in the procerebrum in a manner similar to odor stimulation of the olfactory epithelium on the optic tentacles of another land snail species, Cantareus aspersa (previously known as Helix aspersa). While Euglandina learn to follow trails of novel chemicals that they contact with their lip extensions in one to three trials, these snails proved remarkably resistant to associative learning in the olfactory modality. Even after seven to nine pairings of odorant molecules with food, they showed no orientation toward the conditioned odor. This is in marked contrast to Cantareus snails, which reliably oriented toward conditioned odors after two to three trials. Conclusions The apparent inability of Euglandina to learn to associate food with odors and use odor cues to drive behavior suggests that the capability for sophisticated neural processing of nonvolatile mucus cues detected by the lip extensions has evolved at the expense of processing of odorant

  4. 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.

  5. Transcriptomic responses of Biomphalaria pfeifferi to Schistosoma mansoni: Investigation of a neglected African snail that supports more S. mansoni transmission than any other snail species.

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    Sarah K Buddenborg

    2017-10-01

    Full Text Available Biomphalaria pfeifferi is highly compatible with the widespread human-infecting blood fluke Schistosoma mansoni and transmits more cases of this parasite to people than any other snail species. For these reasons, B. pfeifferi is the world's most important vector snail for S. mansoni, yet we know relatively little at the molecular level regarding the interactions between B. pfeifferi and S. mansoni from early-stage sporocyst transformation to the development of cercariae.We sought to capture a portrait of the response of B. pfeifferi to S. mansoni as it occurs in nature by undertaking Illumina dual RNA-Seq on uninfected control B. pfeifferi and three intramolluscan developmental stages (1- and 3-days post infection and patent, cercariae-producing infections using field-derived west Kenyan specimens. A high-quality, well-annotated de novo B. pfeifferi transcriptome was assembled from over a half billion non-S. mansoni paired-end reads. Reads associated with potential symbionts were noted. Some infected snails yielded fewer normalized S. mansoni reads and showed different patterns of transcriptional response than others, an indication that the ability of field-derived snails to support and respond to infection is variable. Alterations in transcripts associated with reproduction were noted, including for the oviposition-related hormone ovipostatin and enzymes involved in metabolism of bioactive amines like dopamine or serotonin. Shedding snails exhibited responses consistent with the need for tissue repair. Both generalized stress and immune factors immune factors (VIgLs, PGRPs, BGBPs, complement C1q-like, chitinases exhibited complex transcriptional responses in this compatible host-parasite system.This study provides for the first time a large sequence data set to help in interpreting the important vector role of the neglected snail B. pfeifferi in transmission of S. mansoni, including with an emphasis on more natural, field-derived specimens. We

  6. Susceptibility of Snails to Infection with Schistosomes is influenced by Temperature and Expression of Heat Shock Proteins

    Science.gov (United States)

    Knight, Matty; Elhelu, O; Smith, M; Haugen, B; Miller, A; Raghavan, N; Wellman, C; Cousin, C; Dixon, F; Mann, V; Rinaldi, G; Ittiprasert, W; Brindley, PJ

    2015-01-01

    The freshwater snail, Biomphalaria glabrata is the obligate intermediate host for the transmission of the parasitic trematode, Schistosoma mansoni the causative agent of the chronic debilitating neglected tropical disease, schistosomiasis. We showed previously that in juvenile snails, early and significant induction of stress manifested by the expression of stress proteins, Hsp 70, Hsp 90 and reverse transcriptase (RT) of the non- LTR retrotransposon, nimbus, is a characteristic feature of juvenile susceptible NMRI but not resistant BS-90 snails. These latter, however, could be rendered susceptible after mild heat shock at 32°C, revealing that resistance in the BS-90 resistant snail to schistosomes is a temperature dependent trait. Here we tested the hypothesis that maintenance of BS-90 resistant snails at the permissive temperature for several generations affects the resistance phenotype displayed at the non-permissive temperature of 25°C. The progeny of BS-90 snails bred and maintained through several generations (F1 to F4) at 32°C were susceptible to the schistosome infection when returned to room temperature, shedding cercariae at four weeks post-infection. Moreover, the study of expression levels of the heat shock protein (Hsp) 70 protein by ELISA and western blot analysis, showed that this protein is also differentially expressed between susceptible and resistant snails, with susceptible snails expressing more protein than their resistant counterparts after early exposure to wild-type but not to radiation-attenuated miracidia. These data suggested that in the face of global warming, the ability to sustain a reduction in schistosomiasis by using refractory snails as a strategy to block transmission of the disease might prove challenging since non-lethal elevation in temperature, affects snail susceptibility to S. mansoni. PMID:26504668

  7. Snail transcription factor NLS and importin β1 regulate the subcellular localization of Cathepsin L and Cux1.

    Science.gov (United States)

    Burton, Liza J; Henderson, Veronica; Liburd, Latiffa; Odero-Marah, Valerie A

    2017-09-09

    Several recent studies have highlighted an additional unexpected localization and site of action for Cathepsin L (Cat L) protease within the nucleus in breast, colon and prostate cancer, however, its role in the nucleus was unclear. It was proposed to mediate proteolytic processing of the transcription factor CCAAT-displacement protein/cut homeobox transcription factor (Cux1) from the full-length p200 isoform to generate the p110 and p90 isoforms, of which the p110 isoform was shown to act as a cell cycle regulator to accelerate entry into the S phase. The p110 isoform has also been shown to bind to the promoter regions of Snail and E-cadherin to activate Snail and inactivate E-cadherin transcription, thus promoting epithelial mesenchymal transition (EMT). Mechanistic studies on what drives Cat L nuclear localization have not been reported. Our hypothesis is that Snail shuttles into the nucleus with Cat L through binding to importin-β. Snail knockdown with siRNA in MDA-MB-468 breast cancer cells led to nuclear to cytoplasmic shuttling of Cat L and decreased levels of Cux1, while overexpression of Snail in MCF-7 breast cancer cells or HEK-293 human embryonic kidney cells led to increased nuclear expression of both Cat L and Cux1. Additionally, transient transfection of Snail NLS mutants not only abrogated Snail nuclear localization but also nuclear localization of Cat L and Cux1. Interestingly, importin β1 knockdown with siRNA decreased Snail and Cux1 levels, as well as nuclear localization of Cat L. Therefore, we show for the first time that the nuclear localization of Cat L and its substrate Cux1can be positively regulated by Snail NLS and importin β1, suggesting that Snail, Cat L and Cux1 all utilize importin β1 for nuclear import. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Mitogenomic phylogeny of cone snails endemic to Senegal.

    Science.gov (United States)

    Abalde, Samuel; Tenorio, Manuel J; Afonso, Carlos M L; Zardoya, Rafael

    2017-07-01

    Cone snails attain in Senegal one of their highest peaks of species diversity throughout the continental coast of Western Africa. A total of 15 endemic species have been described, all placed in the genus Lautoconus. While there is ample data regarding the morphology of the shell and the radular tooth of these species, virtually nothing is known regarding the genetic diversity and phylogenetic relationships of one of the most endangered groups of cones. In this work, we determined the complete or near-complete (only lacking the control region) mitochondrial (mt) genomes of 17 specimens representing 11 endemic species (Lautoconus belairensis, Lautoconus bruguieresi, Lautoconus cacao, Lautoconus cloveri, Lautoconus cf. echinophilus, Lautoconus guinaicus, Lautoconus hybridus, Lautoconus senegalensis, Lautoconus mercator, Lautoconus taslei, and Lautoconus unifasciatus). We also sequenced the complete mt genome of Lautoconus guanche from the Canary Islands, which has been related to the cones endemic to Senegal. All mt genomes share the same gene arrangement, which conforms to the consensus reported for Conidae, Neogastropoda and Caenogastropoda. Phylogenetic analyses using probabilistic methods recovered three major lineages, whose divergence coincided in time with sea level and ocean current changes as well as temperature fluctuations during the Messinian salinity crisis and the Plio-Pleistocene transition. Furthermore, the three lineages corresponded to distinct types of radular tooth (robust, small, and elongated), suggesting that dietary specialization could be an additional evolutionary driver in the diversification of the cones endemic to Senegal. The reconstructed phylogeny showed several cases of phenotypic convergence (cryptic species) and questions the validity of some species (ecotypes or phenotypic plasticity), both results having important taxonomic and conservation consequences. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Keanekaragaman Keong Di Pulau Enggano, Bengkulu Utara [the Snails Diversity in Enggano Island, Northern Bengkulu

    OpenAIRE

    Heryanto, Heryanto

    2017-01-01

    Research on the diversity of snails in Enggano, Central Bengkulu was held on 16 April 2015 to 5 May 2015 by taking three sampling sites that are north-western part of Enggano (Kampung Bendung at Desa Banjarsari and Desa Meok), the centralpart of Enggano (Desa Malakoni) and the south-easternpart of Enggano (Desa Kaana). Sampling was conducted using purposive sampling while the analysis using graphical method and statistical cluster and t-test. This study found 722 specimens of snails which co...

  10. Are land snail a signature for the Mesolithic-Neolithic transition

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    David Lubell

    2004-12-01

    Full Text Available Edible land snails, representing food remains, are frequently very abundant in late Pleistocene and early-middle Holocene archaeological sites throughout the circum-Mediterranean region. As such, they appear to represent a signature for a broad spectrum subsistence base as first conceived by Flannery in 1969, and therefore must be in some way related to the transition from foraging to food production. This paper investigates the implications that can be drawn from the presence of these snails through information on their ecology, biology, behaviour and nutritional value as well as the behaviour of the prehistoric human groups who collected and consumed them.

  11. The neuropeptide APGWamide induces imposex in the mud snail, Ilyanassa obsoleta.

    Science.gov (United States)

    Oberdörster, E; McClellan-Green, P

    2000-09-01

    We investigated whether neuropeptides which control sexual differentiation in mollusks can induce imposex-a condition where female snails grow male accessory sex organs after exposure to tributyltin (TBT). Mud snails, Ilyanassa obsoleta, were dosed with one of four neuropeptides: APGWamide, conopressin, LSSFVRIamide, or FMRFamide for seven or fourteen days. TBT and testosterone (T) were used as positive controls and induced imposex as expected. APGWamide significantly induced imposex, with a threshold dose near 10(-)(16) moles. The other neuropeptides had no effect on imposex induction. We propose that TBT could act as a neurotoxin to induce imposex via abnormal release of APGWamide.

  12. Evaluation of cytotoxic effects of atrazine and glyphosate herbicides on Biomphalaria glabrata snails

    OpenAIRE

    Mona, Mohamed H.; Gaafar, Reda M.; Helal, Ibrahim B.; Omran, Nahla E.; Salama, Wesam M.

    2013-01-01

    Biomphalaria glabrata snails were used as bio-indicators for freshwater, atrazine, and glyphosate herbicides. SDS–PAGE protein profiles of B. glabrata snails, isozyme analysis (α- and β-esterase, peroxidase and catalase) and RAPD-PCR were used to detect the genotoxicity caused by the two tested herbicides. SDS–PAGE protein profiles showed bands with different molecular weights (53–220 and 1.82–12.5 KDa). The low molecular weight bands appeared in all treated groups except those exposed to 5 p...

  13. [Surveillance of Oncomelania hupensis snails in Baoying and Gaoyou sections of Li Canal in east route of South-to-North Water Diversion Project].

    Science.gov (United States)

    Li, Wei; Gao, Jin-Bin; Zheng, Bo; Huang, Yi-Xin; Hang, De-Rong; Zhang, Jian-Feng; Lu, Jia-Xiang; He, Yong; Wan, Zhong; Huang, Ya-Ming; Gao, Yang; Zuo, Yin-Ping

    2011-08-01

    To understand the distribution and diffusion of Oncomelania hupensis snails in the Baoying and Gaoyou sections of the Li Canal in the east route of the South-to-North Water Diversion Project. The retrospective survey method was used to investigate the distribution and diffusion of snails in the Baoying and Gaoyou sections of the Li Canal, the conventional survey and the methods of salvage of water and attracting snails were used to detect the distribution of snails in river banks and water. The earliest findings of snails in the Gaoyou section of the Li Canal was in 1955, the northernmost distribution of snails was Dilong ferry at the west dam and east slope of the Li Canal. The dynamic surveillance in the Gaoyou section of the Li Canal from 2001 to 2010 showed that the snail status was of low density and low fluctuation of area, and the distribution range was 119 degrees 24' 36" -119 degrees 25' 34", 32 degrees 48' 30" -32 degrees 54' 05". From 2006 to 2010, the snails were not found by the methods of salvage of water and attracting snails in the surveillance in the Baoying and Gaoyou sections of the Li Canal. So far, there is no evidence showing that the snails spread to northward in the Li Canal, however, it is still necessary to carry out the surveillance of snails and schistosomiasis in the east route of the South-to-North Water Diversion Project.

  14. Copper desorption in flooded agricultural soils and toxicity to the Florida apple snail (Pomacea paludosa): Implications in Everglades restoration

    Energy Technology Data Exchange (ETDEWEB)

    Hoang, Tham C. [Florida International University, Department of Environmental Studies, Ecotoxicology and Risk Assessment, Southeast Environmental Research Center, 3000 NE 151st Street, North Miami, FL 33181 (United States); Rogevich, Emily C. [Florida International University, Department of Environmental Studies, Ecotoxicology and Risk Assessment, Southeast Environmental Research Center, 3000 NE 151st Street, North Miami, FL 33181 (United States); Florida Atlantic University, Department of Biological Sciences, Boca Raton, FL 33431 (United States); Rand, Gary M. [Florida International University, Department of Environmental Studies, Ecotoxicology and Risk Assessment, Southeast Environmental Research Center, 3000 NE 151st Street, North Miami, FL 33181 (United States)], E-mail: randg@fiu.edu; Gardinali, Piero R. [Florida International University, Department of Chemistry, Southeast Environmental Research Center, Miami, FL 33199 (United States); Frakes, Robert A.; Bargar, Timothy A. [U.S. Fish and Wildlife Service, South Florida Ecological Services Office, Vero Beach, FL 32960 (United States)

    2008-07-15

    Copper (Cu) desorption and toxicity to the Florida apple snail were investigated from soils obtained from agricultural sites acquired under the Comprehensive Everglades Restoration Plan. Copper concentrations in 11 flooded soils ranged from 5 to 234 mg/kg on day 0 and from 6.2 to 204 mg/kg on day 28 (steady-state). The steady-state Cu concentration in overlying water ranged from 9.1 to 308.2 {mu}g/L. In a 28-d growth study, high mortality in snails occurred within 9 to 16 d in two of three soil treatments tested. Growth of apple snails over 28 d was affected by Cu in these two treatments. Tissue Cu concentrations by day 14 were 12-23-fold higher in snails exposed to the three soil treatments compared to controls. The endangered Florida snail kite and its main food source, the Florida apple snail, may be at risk from Cu exposure in these managed agricultural soil-water ecosystems. - Copper desorbs from agricultural soils and is toxic to the Florida apple snail.

  15. [Study on spatio-temporal pattern of mountainous Oncomelania hupensis snails at village scale in Eryuan County, Yunnan Province].

    Science.gov (United States)

    Huang, Ning-bo; Yang, Kun; Shi, Xue-wen; Li, Hong-jun; Zhou, Xiao-nong; Dong, Xing-qi

    2014-04-01

    To develop a spatio-temporal model of mountainous Oncomelania hupensis snails based on the Bayesian model, and to analyze and identify the spatio-temporal pattern at a village scale. The data including the intensity and spatial distribution of live and infected snails from 2000 to 2006 and the village boundary were collected. The independent and interactive spatio-temporal models were established, and then the best fitness model was selected to analyze the spatio-temporal pattern of live and infected snails. The interactive model of live snails and the independent model of infected snails were relative fitness models, and the models showed 95% CI (confidence interval) of the spatial and temporal coefficient included zero, and indicated that the spatial and temporal correlation of live and infected snails was not significant at a village scale. There is no significant spatial and temporal correlation of live and infected mountainous snails at a village scale, and the furthermore study should be carried out at a small scale.

  16. Field studies on the transmission and survival of Cyclocoelum mutabile (Digenea) infections in natural snail populations in southern Manitoba, Canada.

    Science.gov (United States)

    McKindsey, C W; McLaughlin, J D

    1995-08-01

    The transmission of Cyclocoelum mutabile to snails was examined under natural conditions by sampling the snail communities of 4 natural ponds that had been exposed experimentally to infection by laboratory-infected coots (Fulica americana). Five of 6 snail species in the ponds, Physa jennessi, Promenetus exacuous, Armiger crista, Gyraulus parvus, and Stagnicola elodes, became infected. No natural infections were found in the few Helisoma trivolvis examined. The second most abundant species Promenetus exacuous was infected most often, whereas Physa jennessi, the most abundant species present, was rarely infected. The temporal pattern of infections in the snail community suggests the transmission window of this parasite in southern Manitoba is limited by both the 14 C hatching threshold of the fluke eggs and the seasonality of ovigerous infections in the coot host. No naturally overwintering infections were found in snails from these ponds, which were examined the following spring. None of the 1,120 laboratory-infected snails placed in cages and held overwinter in the ponds survived, whereas 14 of the 1,120 uninfected control snails kept in the same cages survived. These results are consistent with the hypothesis that C. mutabile must be reestablished in northern waterfowl breeding areas each spring.

  17. Study on the relationship of abnormal transcription factors OCT4, HBP1 and Snail expression with progression of osteosarcoma

    Directory of Open Access Journals (Sweden)

    Li Li

    2016-09-01

    Full Text Available Objective: To study the relationship of abnormal transcription factors OCT4, HBP1 and Snail expression with progression of osteosarcoma. Methods: Surgical removed osteosarcoma tissue specimens were selected as pathology group, surgically removed osteoid osteoma specimens were selected as control group, and the expression levels of gene transcription factors OCT4, HBP1 and Snail, proliferation genes, epithelial-mesenchymal transition marker molecules in tissue specimens were determined. Results: Oct4 and Snail protein levels of pathology group were significantly higher than those of control group and HBP1 protein level was significantly lower than that of control group; C-myc and cyclinD1 protein levels of pathology group were significantly higher than those of control group, positively correlated with OCT4 and negatively correlated with HBP1; p16 and p53 protein levels were significantly lower than those of control group, negatively correlated with OCT4 and positively correlated with HBP1; N-cadherin and Vimentin protein levels of pathology group were significantly higher than those of control group and positively correlated with Snail while E-cadherin and Occludin protein levels were significantly lower than those of control group and negatively correlated with Snail. Conclusion: Oct4 and Snail are highly expressed and HBP1 is lowly expressed in osteosarcoma tissue, Oct4 and Snail can participate in the regulation of cell proliferation, and HBP1 can participate in the regulation of epithelial-mesenchymal transition of cells.

  18. Heavy metal concentrations in a soil-plant-snail food chain along a terrestrial soil pollution gradient

    Energy Technology Data Exchange (ETDEWEB)

    Notten, M.J.M. [Institute of Ecological Science, Department of Systems Ecology, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV, Amsterdam (Netherlands)]. E-mail: martje.notten@ecology.falw.vu.nl; Oosthoek, A.J.P. [Institute of Ecological Science, Department of Systems Ecology, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV, Amsterdam (Netherlands); Rozema, J. [Institute of Ecological Science, Department of Systems Ecology, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV, Amsterdam (Netherlands); Aerts, R. [Institute of Ecological Science, Department of Systems Ecology, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV, Amsterdam (Netherlands)

    2005-11-15

    We investigated concentrations of Zn, Cu, Cd and Pb in the compartments of a soil-plant (Urtica dioica)-snail (Cepaea nemoralis) food chain in four polluted locations in the Biesbosch floodplains, the Netherlands, and two reference locations. Total soil metal concentrations in the polluted locations were 4-20 times higher than those in the reference locations. Positive relationships between the generally low leaf concentrations and the soil concentrations were found for Zn only (r {sup 2} = 0.20). Bioaccumulation of Zn, Cu and Cd was observed in the snail tissues. We found positive relationships between the snail and leaf concentrations for all metals (range r {sup 2} = 0.19-0.46). The relationships between soil and snail concentrations were also positive, except for Cu (range r {sup 2} = 0.15-0.33). These results suggest transfer of metals to C. nemoralis snails from U. dioica leaves and from the soil. Metal transfer from polluted leaves to C. nemoralis is more important than transfer from the soil. - Bioaccumulation and positive snail-leaf relationships suggest metal transfer from Urtica dioica leaves to Cepaea nemoralis snails.

  19. [Retrospective investigation of formation of large-scale Oncomelania snail-ridden area in Maogang Town, Songjiang District, Shanghai City].

    Science.gov (United States)

    Jin, Yan-Jun; Cai, Li; Fei, Sheng-Jun; Sun, Cai-Ying; Shen, Li; Yu, Rui-Fang; Wang, Huai-Xian

    2012-06-01

    To explore the influencing factors of the formation of large-scale Oncomelania snail situation in Maogang Town, so as to provide the scientific evidence for improving snail surveillance in Shanghai. The data about the geography, construction and use of floodgate, and snail status of Maogang Town and its surrounding areas, as well as the meteorology and hydrology of Songjiang District were collected and reviewed, and the factors influencing the formation of snail status were analyzed. The condition of water, soil and temperature in Maogang Town was suitable for snail breeding. By 1993, 75% (18/24) of the mouths flowing to Huangpu River and its branches had been built. From 1991 to 2001, the average annual precipitation of Songjiang District was 7.44% higher than the usual condition. There were two basin-wide floods occurring in 1991 and 1999, respectively. The occurrence of tides reaching or exceeding the warning level (3.50 m) of Mishidu hydrology station was positively correlated with the rainfall in the flood season (between June and September, r = 0.903, P analysis and utilization about schistosomiasis-related natural and social factors. In addition, regular snail surveys are suggested in schistosomiasis non-endemic areas adjacent to snail-infested area.

  20. Survival of the faucet snail after chemical disinfection, pH extremes, and heated water bath treatments

    Science.gov (United States)

    Mitchell, A.J.; Cole, Rebecca A.

    2008-01-01

    The faucet snail Bithynia tentaculata, a nonindigenous aquatic snail from Eurasia, was introduced into Lake Michigan in 1871 and has spread to the mid-Atlantic states, the Great Lakes region, Montana, and most recently, the Mississippi River. The faucet snail serves as intermediate host for several trematodes that have caused large-scale mortality among water birds, primarily in the Great Lakes region and Montana. It is important to limit the spread of the faucet snail; small fisheries equipment can serve as a method of snail distribution. Treatments with chemical disinfection, pH extremes, and heated water baths were tested to determine their effectiveness as a disinfectant for small fisheries equipment. Two treatments eliminated all test snails: (1) a 24-h exposure to Hydrothol 191 at a concentration of at least 20 mg/L and (2) a treatment with 50°C heated water for 1 min or longer. Faucet snails were highly resistant to ethanol, NaCl, formalin, Lysol, potassium permanganate, copper sulfate, Baquacil, Virkon, household bleach, and pH extremes (as low as 1 and as high as 13).

  1. Application of Biosynthesized Silver Nanoparticles for the Control of Land Snail Eobania vermiculata and Some Plant Pathogenic Fungi

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    Safaa M. Ali

    2015-01-01

    Full Text Available The land snail Eobania vermiculata is an important crop pest causing considerable damage in agriculture. The aim of the present work is to evaluate the possibilities of using silver nanoparticles (AgNPs to control the land snail. The AgNPs have been synthesized biologically using white radish (Raphanus sativus var. aegyptiacus. The biosynthesis was regularly monitored by UV-Vis spectroscopy. X-ray diffraction spectra revealed peaks of crystalline nature of AgNPs and the transmission electron micrographs further confirmed the size of the synthesized nanoparticles ranging from 6 to 38 nm. The exposure of the snails and soil matrix to AgNPs in a laboratory experiment reduced the activity and the viability of the land snail (20% of AgNPs treated snails died as well as the frequency of fungal population in the surrounding soil. Moreover histology and ultrastructure alterations have been found in both kidney and the digestive gland of AgNPs treated land snails. The synergistic effect of synthesized AgNPs as antifungal was evaluated and clearly revealed that AgNPs can be effectively used against various plant pathogenic fungi. The present study results may open a new avenue to use the snail as bioindicator organism of environmental pollution.

  2. Blocking of p53-Snail Binding, Promoted by Oncogenic K-Ras, Recovers p53 Expression and function

    Directory of Open Access Journals (Sweden)

    Sun-Hye Lee

    2009-01-01

    Full Text Available Differentially from other kinds of Ras, oncogenic K-Ras, which is mutated approximately 30% of human cancer, does not induce apoptosis and senescence. Here, we provide the evidence that oncogenic K-Ras abrogates p53 function and expression through induction of Ataxia telangiectasia-mutated and Rad3-related mediated Snail stabilization. Snail directly binds to DNA binding domain of p53 and diminishes the tumor-suppressive function of p53. Thus, elimination of Snail through si-RNA can induce p53 in K-Ras-mutated cells, whereas Snail and mutant K-Ras can suppress p53 in regardless of K-Ras status. Chemicals, isolated from inhibitor screening of p53-Snail binding, can block the Snail-mediated p53 suppression and enhance the expression of p53 as well as the transcriptional activity of p53 in an oncogenic K-Ras-dependent manner. Among the chemicals, two are very similar in structure. These results can answer why K-Ras can coexist with wild type p53 and propose the Snail-p53 binding as the new therapeutic target for K-Ras-mutated cancers including pancreatic, lung, and colon cancers.

  3. Schistosoma haematobium detection in snails by DraI PCR and Sh110/Sm-Sl PCR: further evidence of the interruption of schistosomiasis transmission in Morocco.

    Science.gov (United States)

    Amarir, Fatima; Sebti, Faiza; Abbasi, Ibrahim; Sadak, Abderrahim; Fellah, Hajiba; Nhammi, Haddou; Ameur, Btissam; El Idrissi, Abderrahman Laamrani; Rhajaoui, Mohamed

    2014-06-24

    This is the first study in Morocco to estimate snail infection rates at the last historic transmission sites of schistosomiasis, known to be free from new infection among humans since 2004. Screening of large numbers of snails for infection is one way to confirm that Schistosoma haematobium transmission has stopped and does not resurge. A total of 2703 Bulinus truncatus snails were collected from 24 snail habitats in five provinces of Morocco: Errachidia, El Kelaa des Sraghna, Tata, Beni Mellal, and Chtouka Ait Baha. All visible snails were collected with a scoop net or by hand. We used waders and gloves as simple precautions. Snails were morphologically identified according to Moroccan Health Ministry guide of schistosomiasis (1982).All snails were analyzed in pools by molecular tool, using primers from the newly identified repeated DNA sequence, termed DraI, in the S. haematobium group. To distinguish S. bovis and S. haematobium, the snails were analyzed by Sh110/Sm-Sl PCR that was specific of S. haematobium. The results showed that snails from Errachidia, Chtouka Ait Baha, sector of Agoujgal in Tata and sector of Mbarkiya in El kelaa des Sraghna were negative for DraI PCR; but, snails from remaining snail habitats of El Kelaa des Sraghna, Tata and Beni Mellal were positive. This led to suggest the presence of circulating schistosome species (S. haematobium, S. bovis or others) within these positive snail habitats. Subsequently, confirmation with S. haematobium species specific molecular assay, Sh110/Sm-Sl PCR, showed that none of the collected snails were infected by S. haematobium in all historic endemic areas. The absence of S. haematobium infection in snails supports the argument of S. haematobium transmission interruption in Morocco.

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

    Science.gov (United States)

    Robinson, Samuel D; Li, Qing; Bandyopadhyay, Pradip K; Gajewiak, Joanna; Yandell, Mark; Papenfuss, Anthony T; Purcell, Anthony W; Norton, Raymond S; Safavi-Hemami, Helena

    2017-04-01

    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, paralysis and sensory overload. Most conotoxins target the prey's nervous system but evidence of venom peptides targeting neuroendocrine processes is emerging. Examples include vasopressin, RFamide neuropeptides and recently also insulin. To investigate the diversity of hormone/neuropeptide-like molecules 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, including peptides similar to the bee brain hormone prohormone-4, the mollusc ganglia neuropeptide elevenin, and thyrostimulin, a member of the glycoprotein hormone family, and confirmed the presence of insulin. We confirmed that at least two of these peptides are not only expressed in the venom gland but also form part of the injected venom cocktail, unambiguously demonstrating their role in envenomation. Our findings suggest that hormone/neuropeptide-like toxins are a diverse and integral part of the complex envenomation strategy of Conus. Exploration of this group of venom components offers an exciting new avenue for the discovery of novel pharmacological tools and drug candidates, complementary to conotoxins. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. 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. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. A new alien snail species from the Eger stream, Hungary (Mollusca, Ampullariidae

    Directory of Open Access Journals (Sweden)

    Frisóczki, B.

    2016-11-01

    Full Text Available Our macrozoobenthon samplings carried out in the Eger stream during 2015–2016 resulted in recording an alien species Marisa cornuarietis (Linneaus, 1758 the giant ramshorn snail which has not been reported so far from outdoorwaters in Hungary. Here we report on collecting several specimens from the urban section of the stream close to the outflow of the Eger thermal spa.

  7. Searching the Human Genome for Snail and Slug With DNA@Home.

    Science.gov (United States)

    Zarns, Kristopher; Desell, Travis; Nechaev, Sergei; Dhasarathy, Archana

    2015-01-01

    DNA@Home is a volunteer computing project that aims to use Gibbs Sampling for the identification and location of DNA control signals on full genome-scale datasets. A fault tolerant and asynchronous implementation of Gibbs sampling using the Berkeley Open Infrastructure for Network Computing (BOINC) was used to identify the location of binding sites of the SNAI1 (Snail) and SNAI2 (Slug) transcription factors across the human genome. Genes regulated by Slug but not Snail, and genes regulated by Snail but not Slug provided two datasets with known motifs. These datasets contained up to 994 DNA sequences which to our knowledge is largest scale use of Gibbs sampling for discovery of binding sites. 1000 parallel sampling walks were used to search for the presence of 1, 2 or 3 possible motifs using small, medium, and full size sets of these sequences. These runs were performed over a period of two months using over 1500 volunteered computing hosts and generated over 2.2 Terabytes of sampling data. High performance computing resources were used for post processing. This paper presents intra and inter walk analyses used to determine walk convergence. The results were validated against current biological knowledge of the Snail and Slug promoter regions and present avenues for further biological study.

  8. Comparative reproductive anatomy in the South African giant land snails (Gastropoda: Pulmonata: Achatinidae)

    NARCIS (Netherlands)

    Mead, A.R.

    2004-01-01

    The history and current taxonomic status of 62 nominal taxa are revised that have been associated in the literature with the subgenus Tholachatina Bequaert, 1950, of genus Archachatina Albers, 1850, and the genus Cochlitoma Férussac, 1821, in the land snail family Achatinidae Swainson, 1840.

  9. Effects of Endosulfan on Predator–Prey Interactions Between Catfish and Schistosoma Host Snails

    NARCIS (Netherlands)

    Monde, Concillia; Syampungani, Stephen; Brink, van den Paul J.

    2016-01-01

    The effect of the pesticide endosulfan on predator–prey interactions between catfish and Schistosoma host snails was assessed in static tank experiments. Hybrid catfish (Clarias gariepinus × C. ngamensis) and Bulinus globosus were subjected to various endosulfan concentrations including an

  10. Fasciola hepatica: Infection Status of Freshwater Snails Collected from Gangwon-do (Province), Korea.

    Science.gov (United States)

    Lee, Jae-Hyung; Quan, Juan-Hua; Choi, In-Wook; Park, Gab-Man; Cha, Guang-Ho; Kim, Hyun-Ju; Yuk, Jae-Min; Lee, Young-Ha

    2017-02-01

    Fasciola hepatica is a trematode that causes zoonosis, mainly in cattle and sheep, and occasionally in humans. Few recent studies have determined the infection status of this fluke in Korea. In August 2015, we collected 402 samples of freshwater snails at Hoenggye-ri (upper stream) and Suha-ri (lower stream) of Song-cheon (stream) in Daegwalnyeong-myeon, Pyeongchang-gun in Gangwon-do (Province) near many large cattle or sheep farms. F. hepatica infection was determined using PCR on the nuclear ribosomal internal transcribed spacer 2 (ITS-2). Among the 402 samples, F. hepatica 1TS-2 marker was detected in 6 freshwater snails; thus, the overall prevalence in freshwater snails was 1.5%. The prevalence varied between collection areas, ranging from 0.0% at Hoenggye-ri to 2.9% at Suha-ri. However, F. gigantica ITS-2 was not detected in the 6 F. hepatica-positive samples by PCR. The nucleotide sequences of the 6 F. hepatica ITS-2 PCR-positive samples were 99.4% identical to the F. hepatica ITS-2 sequences in GenBank, whereas they were 98.4% similar to F. gigantica ITS-2 sequences. These results indicated that the prevalence of F. hepatica in snail intermediate hosts was 1.5% in Gangwon-do, Korea; however the prevalence varied between collection areas. These results may help us to understand F. hepatica infection status in natural environments.

  11. 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.

  12. Drought, Snails, and Large-Scale Die-Off of Southern U.S. Salt Marshes

    NARCIS (Netherlands)

    Silliman, Brian R.; Koppel, Johan van de; Bertness, Mark D.; Stanton, Lee E.; Mendelssohn, Irving A.

    2005-01-01

    Salt marshes in the southeastern United States have recently experienced massive die-off, one of many examples of widespread degradation in marine and coastal ecosystems. Although intense drought is thought to be the primary cause of this die-off, we found snail grazing to be a major contributing

  13. Drought, snails, and large-scale die-off of Southern U.S. salt marshes

    NARCIS (Netherlands)

    Silliman, B.R.; Van de Koppel, J.; Bertness, M.D.; Stanton, L.; Mendelssohn, I.A.

    2005-01-01

    Salt marshes in the southeastern United States have recently experienced massive die-off, one of many examples of widespread degradation in marine and coastal ecosystems. Although intense drought is thought to be the primary cause of this die-off, we found snail grazing to be a major contributing

  14. Studying Land Snails: Inquiry with K-W-L or Four Question Strategies.

    Science.gov (United States)

    Coleman, Pamela; Thiessen, Ronda; Wilson, Debbie; Arey, Beth; Barrow, Lloyd H.

    1999-01-01

    Summarizes how a group of teachers prepared a series of elementary-level inquiry experiences that focused on the study of land snails. Recommends and describes the K-W-L and Four Question inquiry strategies for younger and older students respectively. (WRM)

  15. 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

  16. Distribution of trematodes in snails in ponds at integrated small-scale aquaculture farms

    NARCIS (Netherlands)

    Boerlage, A.S.; Graat, E.A.M.; Verreth, J.A.J.; Jong, de M.C.M.

    2013-01-01

    In integrated small-scale aquaculture farming, animal and human excreta maybe used as fish feed and pond fertilizer, thereby enhancing transmission of fish-borne zoonotic trematodes (FZTs) from final hosts, like humans, pigs and chickens, to snails. Areas within a pond could vary in trematode

  17. A checklist of land snails from the west coast islands of Sabah, Borneo (Mollusca, Gastropoda

    Directory of Open Access Journals (Sweden)

    Chee-Chean Phung

    2017-05-01

    Full Text Available Sabah, situated in one of the world’s biodiversity hotspots, has the largest number of islands in Malaysia with more than 500 of various sizes and degrees of isolation. However, information on the islands’ biodiversity is limited. This study provides an up-to-date checklist of land snail species found on 24 west coast islands in Sabah. A total of 67 species (nearly 20% of the total number of land snail species in the state representing 37 genera and 19 families is enumerated based on systematic field surveys of 133 sampling plots, BORNEENSIS database records and species checklists published between 2000 and 2016. The number of species on the islands ranges from four to 29. Labuan Island has the highest number of species (29, followed by Tiga Island (25, Mantanani Besar Island (24 and Gaya Island (23. However, the populations of some land snail species may have declined as several previously recorded species on the islands were not found in a recent systematic field sampling. This checklist is provided as a baseline inventory for future island land snail studies and to better inform biodiversity conservation plans of marine parks and other islands on the Sabah west coast.

  18. Non-adaptive speciation of snails by left-right reversal is facilitated on oceanic islands

    NARCIS (Netherlands)

    Hoso, M.

    2012-01-01

    The nearly neutral theory of molecular evolution predicts that small population size is essential for non-adaptive evolution. Evolution of whole-body left-right reversal in snails is generally a compelling example of non-adaptive speciation, because variants with reversed chirality would suffer from

  19. Brooding in a temperate zone land snail: seasonal and regional patterns

    NARCIS (Netherlands)

    Sulikowska-Drozd, A.; Maltz, T.K.; Kappes, H.

    2013-01-01

    The goal of this study is to assess if the reproductive strategy of a brooding land snail shifts along a climatic gradient. We focused on the following traits: timing and length of the reproductive season, brood size, ontogenetic dynamics of embryos, and reproductive mode (viviparity versus

  20. Pseudoglessula Libera, a new Subulinid land snail from Guinea, West Africa (Mollusca, Gastropoda Pulmonata)

    NARCIS (Netherlands)

    Solem, A.; Bruggen, van A.C.

    1976-01-01

    Study of some land snails collected in Guinea, West Africa, by Ms. Diane deVry has led to the description of a new species, Pseudoglessula libera. It is currently known only from several localities near Conakry, but probably has a wide distribution. Detailed comparisons with previously described

  1. A checklist of land snails from the west coast islands of Sabah, Borneo (Mollusca, Gastropoda).

    Science.gov (United States)

    Phung, Chee-Chean; Yu, Fred Tuh Yit; Liew, Thor-Seng

    2017-01-01

    Sabah, situated in one of the world's biodiversity hotspots, has the largest number of islands in Malaysia with more than 500 of various sizes and degrees of isolation. However, information on the islands' biodiversity is limited. This study provides an up-to-date checklist of land snail species found on 24 west coast islands in Sabah. A total of 67 species (nearly 20% of the total number of land snail species in the state) representing 37 genera and 19 families is enumerated based on systematic field surveys of 133 sampling plots, BORNEENSIS database records and species checklists published between 2000 and 2016. The number of species on the islands ranges from four to 29. Labuan Island has the highest number of species (29), followed by Tiga Island (25), Mantanani Besar Island (24) and Gaya Island (23). However, the populations of some land snail species may have declined as several previously recorded species on the islands were not found in a recent systematic field sampling. This checklist is provided as a baseline inventory for future island land snail studies and to better inform biodiversity conservation plans of marine parks and other islands on the Sabah west coast.

  2. Effects of snails, submerged plants and their coexistence on eutrophication in aquatic ecosystems

    Directory of Open Access Journals (Sweden)

    Mo Shuqing

    2017-01-01

    Full Text Available Eutrophication resulting from nutrient loading to freshwater habitats is a severe problem, leading to degradation of ecosystems, including deterioration of water quality, water clarity and loss of biodiversity. Measures enacted to restore degraded freshwater ecosystems often involve the reintroduction of submerged plants and aquatic animals with beneficial ecological functions. In a mesocosm experiment, three treatments (planting with Vallisneria natans, introduction of the snail Bellamya aeruginosa and a combined treatment with both plants and snails were compared with controls to evaluate their effects on trophic state. The total nitrogen (TN, total phosphorus (TP and chlorophyll a (Chl a concentrations of planktonic and benthic algal samples were determined every two weeks, along with light intensity at the sediment surface. The plant-only treatment significantly reduced the TN levels and planktonic and benthic algal biomass and increased the light intensity at the sediment surface. The snail-only treatment reduced the concentrations of TN and reduced planktonic and benthic algal biomass. The combined treatment decreased the concentrations of TN and TP, reduced planktonic algal biomass and increased the light intensity on the sediment surface. The results indicate that while submerged plants and snails can both improve water quality, the most pronounced effect in aquatic ecosystems is achieved by their presence in combination. A combined reintroduction approach may provide enhanced benefits in restoring the eutrophic ecosystems, following the reduction of external nutrient loading.

  3. PLCE1 Promotes Esophageal Cancer Cell Progression by Maintaining the Transcriptional Activity of Snail

    Directory of Open Access Journals (Sweden)

    Shicong Zhai

    2017-03-01

    Full Text Available Esophageal cancer is among the most deadly malignant diseases. However, the genetic factors contributing to its occurrence are poorly understood. Multiple studies with large clinic-based cohorts revealed that variations of the phospholipase C epsilon (PLCE1 gene were associated with esophageal cancer susceptibility. However, the causative role of PLCE1 in esophageal cancer is not clear. We inactivated the functional alleles of PLCE1 by CRISPR/Cas9 genome editing technology. The resultant PLCE1 inactivated cells were analyzed both in vitro and in vivo. Our results showed that loss of PLCE1 dramatically decreased the invasion and proliferation capacity of esophageal carcinoma cells in vitro. Moreover, such PLCE1 inactivated tumor grafts exhibited significantly decreased tumor size in mice. We found that PLCE1 was required to maintain protein level of snail a key transcription factor responsible for invasion. Our further transcriptomic data revealed that deficient cells were significantly decreased in expression of genes enriched as targets of Snail. Strikingly, recovery of Snail protein at least partially rescued the invasion and proliferation capacity in PLCE1 inactivated cells. In ESCC clinical specimens, PLCE1 was correlated with tumor stage (P < .0001. Interestingly, PLCE1 expression was positively correlated Snail by immunohistochemistry in such specimens (P < .0001. Therefore, our functional experiments showed the essential roles of PLCE1 in esophageal carcinoma cells and provided evidences that targeting PLCE1 and its downstream molecules could be effective therapies for esophageal cancer.

  4. Tropical sea snail shells: Possible exotic sources for ceramic biomaterial synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Oktar, F. N. [Bioengineering Dept., Faculty of Engineering, Marmara Univ., Istanbul, Turkey, and Medical Imaging Technics Dept., School of Health Related Professions, Marmara Univ., Istanbul, Turkey, and Nanotechnology and Biomaterials Research and Application Cen (Turkey); Kiyici, I. A. [Graduate School of Natural and Applied Sciences, Biomedical Engineering, Kocaeli University, Kocaeli (Turkey); Gökçe, H. [Metallurgical and Materials Engineering Dept., Istanbul Technical Univ., Istanbul, Turkey, and Prof. Dr. Adnan Tekin Material Sciences and Production Technologies Applied Research Center, Istanbul Technical Univ., Istanbul (Turkey); Ağaogulları, D.; Kayali, E. S. [Metallurgical and Materials Engineering Dept., Istanbul Technical Univ., Istanbul (Turkey)

    2013-12-16

    In this study, chemical and structural properties of sea snail shell based bioceramic materials (i.e. hydroxyapatite, whitlockite and other phases) are produced by using mechano-chemical (ultrasonic) conversion method. For this purpose, differential thermal and gravimetric analysis (DTA/TG), X-ray diffraction, infra-red (IR) and scanning electron microscope (SEM) studies are performed.

  5. Use of the dart apparatus by the hermaphroditic land snail Polymita muscarum (Lea, 1834).

    NARCIS (Netherlands)

    Reyes-Tur, B.; Koene, J.M.

    2007-01-01

    Many species of pulmonate land snails are equipped with one or more so-called "love darts". Even though the number and shape of these calcareous darts vary considerably between species, dart use has only been investigated in very few species. Here, we redescribe the mating behaviour of Polymita

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

    NARCIS (Netherlands)

    Schilthuizen, M.

    2003-01-01

    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

  7. Turning snails into slugs: induced body plan changes and formation of an internal shell.

    Science.gov (United States)

    Osterauer, Raphaela; Marschner, Leonie; Betz, Oliver; Gerberding, Matthias; Sawasdee, Banthita; Cloetens, Peter; Haus, Nadine; Sures, Bernd; Triebskorn, Rita; Köhler, Heinz-R

    2010-01-01

    The archetypal body plan of conchiferan molluscs is characterized by an external calcareous shell, though internalization of shells has evolved independently in a number of molluscan clades, including gastropod families. In gastropods, the developmental process of torsion is regarded as a hallmark that is associated with a new anatomical configuration. This configuration is present in extant prosobranch gastropod species, which predominantly bear external shells. Here, we show that short-term exposure to platinum during development uncouples at least two of the processes associated with torsion of the freshwater snail Marisa cornuarietis. That is, the anus of the treated snails is located anteriorly, but the gill and the designated mantle tissue remains in a posterior location, thus preventing the formation of an external shell. In contrast to the prosobranchian archetype, platinum treatment results in the formation of a posterior gill and a cone-shaped internal shell, which persists across the lifetime. This first finding of artificially induced snail-slug conversion was also seen in the pulmonate snail Planorbarius corneus and demonstrates that selective alteration of embryonic key processes can result in fundamental changes of an existing body plan and-if altered regulation is inherited-may give rise to a new one. © 2010 Wiley Periodicals, Inc.

  8. Page 1 Structure & Life-History of C. andhraensis from Apple Snail P ...

    Indian Academy of Sciences (India)

    those of Sewell (1922), Faruqui (1930), Chatterji (1932) and Peter (1955). It would appear that the trematode infestation in the apple snail P. globosa has not hitherto received adequate attention in India. Among the echino- stome cercariae so far known from this country the present cercaria resem- bles C. indicae XII Sewell, ...

  9. Effect of Sources of Fibre on Performance of Growing Snail | Mayaki ...

    African Journals Online (AJOL)

    The effect of feeds produced with cassava leaf and peel meals on the performance of growing snails was also investigated. Feeds (F1, F2 and F3) were formulated to contain 240, 235 and 230 g/kg cassava root meal each and 85, 85 and 90 g/kg cassava peel meal, wheat offal meal and cassava leaf meal respectively.

  10. Ecology and conservation of the land-snails of the Eastern Arc ...

    African Journals Online (AJOL)

    In contrast, diversity and abundance is low in the forests of the Nguru Mountains. A similarity analysis is used to identify several clusters of sites that are related to geographical position and altitude. The significance of these findings for the conservation of East African land snails is discussed. Journal of East African Natural ...

  11. 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.

  12. Diagnostic of Biomphalaria snails and Schistosoma mansoni: DNA obtained from traces of shell organic materials

    Directory of Open Access Journals (Sweden)

    Roberta L Caldeira

    2004-08-01

    Full Text Available Freshwater snails belonging to the genus Biomphalaria act as intermediate hosts for the parasite trematode Schistosoma mansoni in Africa and in the neotropical region. Identification of such molluscs is carried out based on morphological characters and the presence of cercariae is verified through squeezing snails between two glass slides or by exposing them to artificial light. However, sometimes, the material collected includes molluscs with decomposed bodies or, yet, only empty shells, which precludes their identification and S. mansoni detection. Due to these difficulties, we have developed a methodology in which DNA may be extracted from traces of organic material from inside shells in order to identify molluscs through polymerase chain reaction and restriction fragment length polymorphism and to detect S. mansoni into these snails, by using low stringency polymerase chain reaction. Species-specific profiles obtained from B. glabrata, B. straminea, and B. tenagophila snails and their shells, maintained in laboratory for ten years, showed the same profiles. S. mansoni profiles showed to be present in shell specimens as far as the eighth week after being removed from aquarium.

  13. The love-darts of land snails: integrating physiology, morphology and behaviour

    NARCIS (Netherlands)

    Lodi, M.; Koene, J.M.

    2016-01-01

    Several land-snail species of the helicoid and limacoid superfamilies possess one or more love-darts, which seem to have evolved as a result of conflict over the fate of donated sperm and/or as a way to select the most fit sperm donor. A love-dart is a calcareous stylet used during mating encounters

  14. Tales of two snails: sexual selection and sexual conflict in Lymnaea stagnalis and Helix aspersa.

    NARCIS (Netherlands)

    Koene, J.M.

    2006-01-01

    Sexual selection and sexual conflict have been shown to play key roles in the evolution of species with separate sexes. Experimental evidence is accumulating that this is also true for simultaneous hermaphrodites. For example, many species of land snails forcefully stab their mating partners with

  15. Larval development of Angiostrongylus vasorum in the land snail Helix aspersa.

    Science.gov (United States)

    Di Cesare, Angela; Crisi, Paolo Emidio; Bartolini, Roberto; Iorio, Raffaella; Talone, Tonino; Filippi, Laura; Traversa, Donato

    2015-10-01

    The metastrongyloid nematode Angiostrongylus vasorum affects the heart and pulmonary arteries of dogs and wild animals. Over the recent years, dog angiostrongylosis has gained great attention in the veterinary community for the expansion of its geographic range and for a rise in the number of clinical cases. Global warming, changes in phenology of mollusc intermediate hosts and movements of wild reservoirs have been evocated in the spreading of mollusc-borne parasites, including A. vasorum. The land snail Helix aspersa, a vector of other respiratory metastrongyloids, is endemic in most regions of the World, where it is a pest outside its native Mediterranean range. In the present study, the susceptibility and suitability of H. aspersa as an intermediate host of A. vasorum were investigated along with the characteristics of larval recovery and development following two different ways of inoculation, i.e. experimental (group A) vs natural infection (group B). After infections, the snails were kept at environmental conditions for 2 months. Five snails from groups A and B were randomly selected, digested and examined at 15-day intervals for 2 months. L1s, L2s and L3s were microscopically identified based on key morphological and morphometric characteristics and their identity was genetically confirmed. The results showed that A. vasorum may reach the infective stage in H. aspersa and that uptake of larvae and parasitic burden within the snails depend on the grazing capability of the molluscs. Biological and epidemiological implications are discussed.

  16. STUDY REGARDING HELIX ASPERSA SNAIL WINTERTIME PROTECTION IN OPEN AIR REARING TECHNOLOGY

    Directory of Open Access Journals (Sweden)

    D. NICA

    2007-10-01

    Full Text Available In Italy the standard wintertime protecting solution used for brown garden snail(Helix aspersa aspersa inside open air rearing technology is to cut the plants to 20cm and to protect the rearing pen with agryl-sheet, named in italian language Tessuto-NonTessuto or for short TNT. But this method isn`t suited for our country colderwinters. Low temperatures registered during 2005 - 2006 winter and hibernationbehaviour inadequate understanding led to high mortality rates, estimated to over85%, in most of the outdoor snail farms all around Romania.In order to solve the problem we studied some aspects of brown garden snail ecologicplasticity, his hibernation behavior inside outdoor snail farms and researched thepossibilities of implementing some alternative wintertime protective methods. As aresult we developed the “sandwich” system based on straw non-conducting propertiesconceived in such a manner to provide an efficient adiabatic protection while theinside aeration is enough to limit as much as possible the straw mass moistening.

  17. Snails as indicators of pesticide drift, deposit, transfer and effects in the vineyard.

    Science.gov (United States)

    Druart, Coline; Millet, Maurice; Scheifler, Renaud; Delhomme, Olivier; Raeppel, Caroline; de Vaufleury, Annette

    2011-09-15

    This paper presents a field-study of real pesticide application conditions in a vineyard. The objective was to measure the exposure, the transfer and the effects of pesticides on a non-target soil invertebrate, the land snail Helix aspersa. There was no drift of the herbicides (glyphosate and glufosinate) whereas the fungicides (cymoxanil, folpet, tebuconazole and pyraclostrobin) were detected up to 20 m from the treated area. For folpet and particularly tebuconazole, spray deposits on soil (corresponding to losses for the intended target i.e. the vine leaves) were high (41.1% and 88.8% loss of applied dose, respectively). For herbicides, the target was the soil and losses (percentage of compounds which did not reach the soil) were of 22% for glufosinate and 52% for glyphosate. In the study plot, glyphosate was transferred to and accumulated in snail tissues (4 mg kg(-1) dry weight, dw), as was its metabolite AMPA (8 mg kg(-1) dw) which could be in relation with the reduced growth observed in snails. No effects on snail survival or growth were found after exposure to the other organic compounds or to copper and sulphur-fungicides, although transfer of tebuconazole, pyraclostrobin and copper occurred. This study brings original field data on the fate of pesticides in a vineyard agro-ecosystem under real conditions of application and shows that transfer and effects of pesticides to a non-target organism occurred. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Unpredictable responses of garden snail ( Helix aspersa) populations to climate change

    Science.gov (United States)

    Bezemer, T. Martijn; Knight, Kevin J.

    2001-08-01

    We studied the impact of climate change on the population dynamics of the garden snail ( Helix aspersa) in the Ecotron controlled environment facility. The experimental series ran for three plant generations, allowing the snails to reproduce. We investigated the isolated and combined effects of elevated CO 2 (current + 200 μmol mol -1) and warming (current + 2ºC) in three consecutive runs (CO 2, Temperature and Combined). In the CO 2 Run, the number of juvenile snails recorded at the end of the experiment did not differ between ambient and elevated CO 2, whereas in the Temperature Run, fewer juveniles were found at elevated temperatures. An opposite response was observed in the Combined Run, where significantly more juveniles were found in elevated temperature and CO 2 compared to elevated CO 2 on its own. Within each run, juvenile emergence was not affected by treatments but juvenile presence was first observed about 70 days earlier in the Combined Run than in the Temperature Run. The differences in snail performance in the different runs were not correlated with differences in community structure or leaf quality measured as C:N ratios and neither with the abundance of the most preferred host plant species, Cardamine hirsuta. The abundance of this species, however, was significantly altered in all runs. The results illustrate clearly the degree of difficulty in making predictable generalisations about the consequences of climate change for certain species.

  19. Evidence for genetic control of adult weight plasticity in the snail Helix aspersa

    DEFF Research Database (Denmark)

    Ros, Mathieu; Sorensen, Daniel; Waagepetersen, Rasmus Plenge

    2004-01-01

    of adult weight in the snail Helix aspersa. Several models of heterogeneous variance are fitted using a Bayesin, MCMC approach. Exploratory analyses using posterior predictive model checking and model comparisons based on the deviance information criterion favor a model postulating a genetically structured...

  20. Coolidge effect in pond snails: male motivation in a simultaneous hermaphrodite.

    NARCIS (Netherlands)

    Koene, J.M.; ter Maat, A.

    2007-01-01

    Background. The simultaneously hermaphroditic pond snail, Lymnaea stagnalis, can mate in the male and female role, but within one copulation only one sexual role is performed at a time. Previous work has shown that male motivation is determined by the availability of seminal fluid in the prostate

  1. Nutrient availability modulates both host and parasite life histories in a snail-trematode interaction.

    Science.gov (United States)

    Sandland, Gregory J; Josephson, Katherine A

    2017-10-18

    Host nutrient availability can have important life history consequences for hosts and their parasites. The responses of each participant within the association can vary extensively across host-parasite systems. In this paper, we outline the life history responses of the aquatic snail Biomphalaria glabrata and its trematode parasite Echinostoma caproni during host nutrient restriction. The onset of host starvation had rapid and strong effects on snail reproduction, significantly reducing egg output in control snails and eliminating egg production in infected individuals. The combination of E. caproni infection and nutrient restriction also had a dramatic effect on B. glabrata survival, with starved infected snails dying at a faster rate than hosts from any other treatment. In terms of parasite reproduction, host nutrient restriction did not influence the quantity of parasite larvae produced after starvation onset but did influence parasite quality, reducing both larval swimming time and overall longevity. Together these results demonstrate that nutrient restriction can strongly influence both host and parasite life histories, and therefore should be considered in future studies attempting to understand patterns of disease in host populations.

  2. Effects of glyphosate-based herbicides on survival, development and growth of invasive snail (Pomacea canaliculata).

    Science.gov (United States)

    Xu, Yanggui; Li, Adela Jing; Li, Kaibin; Qin, Junhao; Li, Huashou

    2017-12-01

    This study tests the hypotheses that whether environmental relevance of glyphosate would help control spread of the invasive snail Pomacea canaliculata, or benefit its population growth worldwide. Our results showed that glyphosate induced acute toxicity to the snail only at high concentrations (96h LC50 at 175mg/L) unlikely to occur in the environment. Long-term exposures to glyphosate at sublethal levels (20 and 120mg/L) caused inhibition of food intake, limitation of growth performance and alterations in metabolic profiles of the snail. It is worth noting that glyphosate at 2mg/L benefited growth performance in P. canaliculata. Chronic exposures of glyphosate significantly enhanced overall metabolic rate and altered catabolism from protein to carbohydrate/lipid mode. Cellular responses in enzyme activities showed that the exposed snails could increase tolerance by their defense system against glyphosate-induced oxidative stress, and adjustment of metabolism to mitigate energy crisis. Our study displayed that sublethal concentrations of glyphosate might be helpful in control of the invasive species by food intake, growth performance and metabolic interruption; whether environmental relevance of glyphosate (≤2mg/L) benefits population growth of P. canaliculata is still inconclusive, which requires further field study. Copyright © 2017 Elsevier B.V. All rights reserved.

  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...... families and their medical and veterinary importance in Asia but with main focus on Vietnam....

  4. Micro-distribution of freshwater snails before and after water flow ...

    African Journals Online (AJOL)

    Aggregation at the corners of the boxes could be among the factors that enable snail species to avoid the detrimental effect of turbulent water flow during irrigation. The relevance of changes in density and micro-distribution following an irrigation cycle in the control of B. truncatus is discussed. African Journal of Aquatic ...

  5. Characterization of gelatin/chitosan scaffold blended with aloe vera and snail mucus for biomedical purpose.

    Science.gov (United States)

    López Angulo, Daniel Enrique; do Amaral Sobral, Paulo José

    2016-11-01

    Biologically active scaffolds used in tissue engineering and regenerative medicine have been generating promising results in skin replacement. The present study aims to test the hypothesis that the incorporation of Aloe vera and snail mucus into scaffolds based on gelatin and chitosan could improve their structure, composition and biodegradability, with a potential effect on bioactivity. Homogeneous pore diameter as well as pore walls in the composite scaffold could be seen in the SEM image. The pores in the scaffolds were interconnected and their sizes ranged from 93 to 296μm. The addition of Aloe vera and snail mucus enlarged the mean pore size with increased porosity and caused changes in the pore architecture. The FTIR analysis has shown good affinity and interaction between the matrix and the Aloe, which may decrease water-binding sites, so this fact hindered the water absorption capacity of the material. The mechanical properties could explain the highest swelling capacity of the snail scaffold, because the high percentage of elongation could facilitate the entry of liquid in it, generating a matrix with plenty of fluid retention. The real innovation in the present work could be the use of these substances (Aloe and snail mucus) for tissue engineering. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Effect of snails (Elimia clavaeformis) on phosphorus cycling in stream periphyton and leaf detritus communities

    Energy Technology Data Exchange (ETDEWEB)

    Jay, Elizabeth A. [North Carolina Univ., Chapel Hill, NC (United States)

    1993-01-01

    In this study, the author examined the effect of grazing on phosphorus cycling in stream periphyton and leaf detritus communities using the snail Elimia clavaeformis. Phosphorus cycling fluxes and turnover rates were measured in a laboratory and in a natural stream, respectively, using radioactive tracer techniques.

  7. Symptoms of behavioural anapyrexia--reverse fever as a defence response of snails to fluke invasion.

    Science.gov (United States)

    Zbikowska, Elżbieta; Cichy, Anna

    2012-03-01

    The subject of the research was the thermal preferences of Planorbarius corneus individuals infected by larvae of digenetic trematodes. Snails were obtained over two consecutive years, 2009 and 2010, from 10 water bodies located in central Poland. The relationship between the seasons and the occurrence of patent invasions in hosts found in the shore-zone of lakes was observed. Behavioural experiments conducted on P. corneus individuals placed in a thermal gradient demonstrated that parasite infection had an impact on the thermal preferences of the snails. Individuals that shed cercariae of Bilharziella polonica, Cotylurus sp., Notocotylus ephemera, Rubenstrema exasperatum/Neoglyphe locellus, Rubenstrema opisthovitellinum, or Tylodelphys excavata displayed symptoms of behavioural anapyrexia, similarly to experimentally injured snails. This response increased the survival of infected individuals while simultaneously prolonging the period of shedding of dispersive forms of parasites. This point of view was upheld by the observation that infected snails bred at 19°C lived longer than at 26°C and the shedding rate of cercariae at a lower temperature was lower than at a higher one. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. Snail involves in the transforming growth factor β1-mediated epithelial-mesenchymal transition of retinal pigment epithelial cells.

    Directory of Open Access Journals (Sweden)

    Hui Li

    Full Text Available BACKGROUND: The proliferation of retinal pigment epithelium (RPE cells resulting from an epithelial-mesenchymal transition (EMT plays a key role in proliferative vitreoretinopathy (PVR, which leads to complex retinal detachment and the loss of vision. Genes of Snail family encode the zinc finger transcription factors that have been reported to be essential in EMT during embryonic development and cancer metastasis. However, the function of Snail in RPE cells undergoing EMT is largely unknown. PRINCIPAL FINDINGS: Transforming growth factor beta(TGF-β-1 resulted in EMT in human RPE cells (ARPE-19, which was characterized by the expected decrease in E-cadherin and Zona occludin-1(ZO-1 expression, and the increase in fibronectin and α-smooth muscle actin (α-SMA expression, as well as the associated increase of Snail expression at both mRNA and protein levels. Furthermore, TGF-β1 treatment caused a significant change in ARPE-19 cells morphology, with transition from a typical epithelial morphology to mesenchymal spindle-shaped. More interestingly, Snail silencing significantly attenuated TGF-β1-induced EMT in ARPE-19 cells by decreasing the mesenchymal markers fibronectin and a-SMA and increasing the epithelial marker E-cadherin and ZO-1. Snail knockdown could effectively suppress ARPE-19 cell migration. Finally, Snail was activated in epiretinal membranes from PVR patients. Taken together, Snail plays very important roles in TGF-β-1-induced EMT in human RPE cells and may contribute to the development of PVR. SIGNIFICANCE: Snail transcription factor plays a critical role in TGF-β1-induced EMT in human RPE cells, which provides deep insight into the pathogenesis of human PVR disease. The specific inhibition of Snail may provide a new approach to treat and prevent PVR.

  9. New insight in lymnaeid snails (Mollusca, Gastropoda) as intermediate hosts of Fasciola hepatica (Trematoda, Digenea) in Belgium and Luxembourg.

    Science.gov (United States)

    Caron, Yannick; Martens, Koen; Lempereur, Laetitia; Saegerman, Claude; Losson, Bertrand

    2014-02-13

    The present study aims to assess the epidemiological role of different lymnaeid snails as intermediate hosts of the liver fluke Fasciola hepatica in Belgium and Luxembourg. During summer 2008, 7103 lymnaeid snails were collected from 125 ponds distributed in 5 clusters each including 25 ponds. Each cluster was located in a different biogeographic area of Belgium and Luxembourg. In addition, snails were also collected in sixteen other biotopes considered as temporary wet areas. These snails were identified as Galba truncatula (n = 2474) (the main intermediate host of F. hepatica in Europe) and Radix sp. (n = 4629). Moreover, several biological and non-biological variables were also recorded from the different biotopes. DNA was extracted from each snail collected using Chelex® technique. DNA samples were screened through a multiplex PCR that amplifies lymnaeid internal transcribed spacer 2 gene sequences (500-600 bp) (acting as an internal control) and a 124 bp fragment of repetitive DNA from Fasciola sp. Lymnaeid snails were found in 75 biotopes (53.2%). Thirty individuals of G. truncatula (1.31%) and 7 of Radix sp. (0.16%) were found to be positive for Fasciola sp. The seven positive Radix sp. snails all belonged to the species R. balthica (Linnaeus, 1758). Classification and regression tree analysis were performed in order to better understand links and relative importance of the different recorded factors. One of the best explanatory variables for the presence/absence of the different snail species seems to be the geographic location, whereas for the infection status of the snails no obvious relationship was linked to the presence of cattle. Epidemiological implications of these findings and particularly the role of R. balthica as an alternative intermediate host in Belgium and Luxembourg were discussed.

  10. Population genetics and the effects of a severe bottleneck in an ex situ population of critically endangered Hawaiian tree snails.

    Science.gov (United States)

    Price, Melissa R; Hadfield, Michael G

    2014-01-01

    As wild populations decline, ex situ propagation provides a potential bank of genetic diversity and a hedge against extinction. These programs are unlikely to succeed if captive populations do not recover from the severe bottleneck imposed when they are founded with a limited number of individuals from remnant populations. In small captive populations allelic richness may be lost due to genetic drift, leading to a decline in fitness. Wild populations of the Hawaiian tree snail Achatinella lila, a hermaphroditic snail with a long life history, have declined precipitously due to introduced predators and other human impacts. A captive population initially thrived after its founding with seven snails, exceeding 600 captive individuals in 2009, but drastically declined in the last five years. Measures of fitness were examined from 2,018 captive snails that died between 1998 and 2012, and compared with genotypic data for six microsatellite loci from a subset of these deceased snails (N = 335), as well as live captive snails (N = 198) and wild snails (N = 92). Surprisingly, the inbreeding coefficient (Fis) declined over time in the captive population, and is now approaching values observed in the 2013 wild population, despite a significant decrease in allelic richness. However, adult annual survival and fecundity significantly declined in the second generation. These measures of fitness were positively correlated with heterozygosity. Snails with higher measures of heterozygosity had more offspring, and third generation offspring with higher measures of heterozygosity were more likely to reach maturity. These results highlight the importance of maintaining genetic diversity in captive populations, particularly those initiated with a small number of individuals from wild remnant populations. Genetic rescue may allow for an increase in genetic diversity in the captive population, as measures of heterozygosity and rarified allelic richness were higher in wild tree

  11. Field and laboratory evaluation of the influence of copper-diquat on apple snails in southern Florida

    Science.gov (United States)

    Winger, P.V.; Imlay, M.J.; McMillan, W.E.; Martin, T.W.; Takekawa, Jean E.; Johnson, W.W.

    1984-01-01

    The recent decline of apple snail (Pomacea paludosa) populations in canals surrounding Loxahatchee National Wildlife Refuge in southern Florida coincided with the use of copper-diquat for the control of the aquatic weed hydrilla (Hydrilla verticillata). Field and laboratory studies were designed to assess the effects of copper-diquat on apple snails, which are the primary food of the endangered snail kite Rostrhamus sociabilis (formerly known as the Everglade kite). Acute toxicities (96-h LC50 values) of Cutrine-Plus and Komeen (chelated formulations of copper) to immature apple snails were 22 and 24 μg/L, respectively. Diquat was toxic at a concentration of 1,800 μg/L and did not increase the toxicity of copper when the chemicals were used in combination. Evaluation of field samples indicated that copper concentrations were higher in detritus than in water, plants and mud, and that there was a gradient of copper concentration from the canal to the interior, the highest residues being in samples from the canal. Copper associated with detritus (up to 150 μg/g) had no effect on growth or survival of apple snails in field cage and tank studies. Also, field applications of copper-diquat to hydrilla had no effect on survival of caged adult and immature snails. Copper from field applications was rapidly taken out of solution by plants and organic material in the water and subsequently incorporated into the bottom detritus. Although the effects of repeated applications of copper-diquat and high body burdens of copper (accumulated during exposure to herbicidal treatment) on survival and reproduction of apple snails are not known, the information available indicates that treatment of hydrilla with copper-diquat was probably not responsible for the decline in the apple snail population. Application at recommended rates should pose no threat to these snails in the organically rich waters of southern Florida.

  12. New insight in lymnaeid snails (Mollusca, Gastropoda) as intermediate hosts of Fasciola hepatica (Trematoda, Digenea) in Belgium and Luxembourg

    Science.gov (United States)

    2014-01-01

    Background The present study aims to assess the epidemiological role of different lymnaeid snails as intermediate hosts of the liver fluke Fasciola hepatica in Belgium and Luxembourg. Methods During summer 2008, 7103 lymnaeid snails were collected from 125 ponds distributed in 5 clusters each including 25 ponds. Each cluster was located in a different biogeographic area of Belgium and Luxembourg. In addition, snails were also collected in sixteen other biotopes considered as temporary wet areas. These snails were identified as Galba truncatula (n = 2474) (the main intermediate host of F. hepatica in Europe) and Radix sp. (n = 4629). Moreover, several biological and non-biological variables were also recorded from the different biotopes. DNA was extracted from each snail collected using Chelex® technique. DNA samples were screened through a multiplex PCR that amplifies lymnaeid internal transcribed spacer 2 gene sequences (500–600 bp) (acting as an internal control) and a 124 bp fragment of repetitive DNA from Fasciola sp. Results Lymnaeid snails were found in 75 biotopes (53.2%). Thirty individuals of G. truncatula (1.31%) and 7 of Radix sp. (0.16%) were found to be positive for Fasciola sp. The seven positive Radix sp. snails all belonged to the species R. balthica (Linnaeus, 1758). Classification and regression tree analysis were performed in order to better understand links and relative importance of the different recorded factors. One of the best explanatory variables for the presence/absence of the different snail species seems to be the geographic location, whereas for the infection status of the snails no obvious relationship was linked to the presence of cattle. Conclusions Epidemiological implications of these findings and particularly the role of R. balthica as an alternative intermediate host in Belgium and Luxembourg were discussed. PMID:24524623

  13. 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.

  14. The identity, distribution, and impacts of non-native apple snails in the continental United States

    Directory of Open Access Journals (Sweden)

    Hayes Kenneth A

    2007-06-01

    Full Text Available Abstract Background Since the mid 1990s populations of non-native apple snails (Ampullariidae have been discovered with increasing frequency in the continental United States. Given the dramatic effects that introduced apple snails have had on both natural habitats and agricultural areas in Southeast Asia, their introduction to the mainland U.S. is cause for concern. We combine phylogenetic analyses of mtDNA sequences with examination of introduced populations and museum collections to clarify the identities, introduced distributions, geographical origins, and introduction histories of apple snails. Results Based on sampling to date, we conclude there are five species of non-native apple snails in the continental U.S. Most significantly, we recognize three species within what has been called the channeled apple snail: Pomacea canaliculata (California and Arizona, Pomacea insularum, (Florida, Texas, and Georgia and Pomacea haustrum (Florida. The first established populations of P. haustrum were discovered in the late 1970s in Palm Beach County Florida, and have not spread appreciably in 30 years. In contrast, populations of P. insularum were established in Texas by 1989, in Florida by the mid to late 1990s, and in Georgia by 2005, and this species continues to spread rapidly. Most introduced P. insularum haplotypes are a close match to haplotypes from the Río Uruguay near Buenos Aires, indicating cold tolerance, with the potential to spread from Florida, Georgia, and Texas through Louisiana, Alabama, Mississippi, and South Carolina. Pomacea canaliculata populations were first discovered in California in 1997. Haplotypes of introduced P. canaliculata match native-range haplotypes from near Buenos Aires, Argentina, also indicating cold tolerance and the potential to establish farther north. Conclusion The term "channeled apple snail" is descriptive of a morphology found in many apple snail species. It does not identify a single species or a

  15. Pulsed-field gel electrophoresis profiles of aeromonads isolated from healthy and diseased Helix aspersa from French snail farms.

    Science.gov (United States)

    Kiebre-Toe, M B; Lacheretz, A; Villard, L; Richard, Y; Kodjo, A

    2005-09-01

    The XbaI digestion patterns of chromosomal DNA of 42 aeromonads isolated from French breeding snails during a new epizootic disease, which rapidly progressed to death during the summer of 1994, were analyzed by pulsed-field gel electrophoresis. Biochemical identification to species level was also performed. Interestingly, we found that 76% of the aeromonads isolated from diseased snails clustered into a unique pulsotype (P1) whatever their geographic origin, and were assessed to belong to Aeromonas hydrophila. Other strains belonged to Aeromonas caviae or remained unspecified. Our results provide retrospective supplementary epidemiological evidence for implication of A. hydrophila strains in the snail summer disease.

  16. Blocking of p53-Snail Binding, Promoted by Oncogenic K-Ras, Recovers p53 Expression and function

    OpenAIRE

    Lee, Sun-Hye; Lee, Su-Jin; Jung, Yeon Sang; Xu, Yongbin; Kang, Ho Sung; Ha, Nam-Chul; Park, Bum-Joon

    2009-01-01

    Differentially from other kinds of Ras, oncogenic K-Ras, which is mutated approximately 30% of human cancer, does not induce apoptosis and senescence. Here, we provide the evidence that oncogenic K-Ras abrogates p53 function and expression through induction of Ataxia telangiectasia-mutated and Rad3-related mediated Snail stabilization. Snail directly binds to DNA binding domain of p53 and diminishes the tumor-suppressive function of p53. Thus, elimination of Snail through si-RNA can induce p5...

  17. Effects of shorebird predation and snail abundance on an intertidal mudflat community

    Science.gov (United States)

    Cheverie, Anne V.; Hamilton, Diana J.; Coffin, Michael R. S.; Barbeau, Myriam A.

    2014-09-01

    Top-down effects of predation are well documented in a variety of ecological communities, including marine soft-sediment systems. It has been proposed that intertidal mudflats in the upper Bay of Fundy, Canada, which host a large population of foraging shorebirds each summer, may exhibit this community dynamic. Biofilm (consisting mainly of diatoms) forms the base of the mudflat community food web, which is dominated by the amphipod Corophium volutator. To assess the potential for a trophic cascade, we conducted a manipulative field experiment examining individual and combined effects of the shorebird Calidris pusilla, a primary predator of C. volutator, and the eastern mudsnail (Nassarius obsoletus), an intraguild predator, on community structure (including macrofauna and large meiofauna retained by a 250-μm screen). Snails exhibited density-dependent top-down effects, primarily from strong negative interactions with juvenile and adult C. volutator, likely due to interference, consumption and emigration. Medium and high densities of snails reduced chlorophyll a concentration (a measure of diatom abundance), likely through consumption and disturbance of the sediment. When present at higher densities, snails also increased variability in community structure. Shorebirds were less influential in determining community structure. They reduced C. volutator biomass through consumption, but there was no resulting effect on primary production. Top-down effects of snails and birds were cumulative on C. volutator, but did not generate a trophic cascade. We suggest that a combination of omnivory and intraguild predation by shorebirds and snails, coupled with relatively low grazing pressure by C. volutator, prevented transmission of top-down effects.

  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. Copyright © 2011 Elsevier Inc. All rights reserved.

  19. Molecular Diversity and Gene Evolution of the Venom Arsenal of Terebridae Predatory Marine Snails.

    Science.gov (United States)

    Gorson, Juliette; Ramrattan, Girish; Verdes, Aida; Wright, Elizabeth M; Kantor, Yuri; Rajaram Srinivasan, Ramakrishnan; Musunuri, Raj; Packer, Daniel; Albano, Gabriel; Qiu, Wei-Gang; Holford, Mandë

    2015-05-28

    Venom peptides from predatory organisms are a resource for investigating evolutionary processes such as adaptive radiation or diversification, and exemplify promising targets for biomedical drug development. Terebridae are an understudied lineage of conoidean snails, which also includes cone snails and turrids. Characterization of cone snail venom peptides, conotoxins, has revealed a cocktail of bioactive compounds used to investigate physiological cellular function, predator-prey interactions, and to develop novel therapeutics. However, venom diversity of other conoidean snails remains poorly understood. The present research applies a venomics approach to characterize novel terebrid venom peptides, teretoxins, from the venom gland transcriptomes of Triplostephanus anilis and Terebra subulata. Next-generation sequencing and de novo assembly identified 139 putative teretoxins that were analyzed for the presence of canonical peptide features as identified in conotoxins. To meet the challenges of de novo assembly, multiple approaches for cross validation of findings were performed to achieve reliable assemblies of venom duct transcriptomes and to obtain a robust portrait of Terebridae venom. Phylogenetic methodology was used to identify 14 teretoxin gene superfamilies for the first time, 13 of which are unique to the Terebridae. Additionally, basic local algorithm search tool homology-based searches to venom-related genes and posttranslational modification enzymes identified a convergence of certain venom proteins, such as actinoporin, commonly found in venoms. This research provides novel insights into venom evolution and recruitment in Conoidean predatory marine snails and identifies a plethora of terebrid venom peptides that can be used to investigate fundamental questions pertaining to gene evolution. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  20. 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.

  1. 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.

  2. Oxygen stable isotopic disparities among sympatric small land snail species from northwest Minnesota, USA

    Science.gov (United States)

    Yanes, Yurena; Nekola, Jeffery C.; Rech, Jason A.; Pigati, Jeffery S.

    2017-01-01

    The oxygen isotopic composition (δ18O) of land snail shells can be a valuable paleoenvironmental archive if the climatic parameters that influence the isotopic system are fully understood. Previous calibration studies have examined a limited number of species or individuals, and most have focused on larger (> 10 mm) taxa, which do not represent the dominant shell material in the Quaternary fossil record. In this study, we evaluate the δ18O values of small land snails (USA), which exhibits extremely abundant and diverse terrestrial malacofauna in North America. We did not observe significant correlations between shell δ18O values and the type of ecosystem (forest/grassland) or hydrologic setting (upland/lowland). However, the majority of species differed significantly in shell δ18O values. Larger taxa (Catinella, Succinea, Discus) consistently yielded higher δ18O values than smaller taxa (Euconulus, Gastrocopta, Hawaiia, Vallonia), by up to ~ 3‰. These isotopic offsets among sympatric taxa could be attributed to a number of physical, behavioral, and/or evolutionary traits, including the ability of larger species to tolerate drier conditions better than their smaller counterparts, differences in their preferred microhabitats or phylogentic non-independence. Regardless of the reason, our results imply that researchers should not combine isotopic data from different types of land snails without first investigating modern specimens to determine if it is appropriate. Moreover, our data suggest that combining instrumental climate data, a snail flux-balance model, and shell δ18O values can help us to better understand the ecology of land snails.

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

    Directory of Open Access Journals (Sweden)

    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.

  4. Modelling chronic exposure to contaminated soil: a toxicokinetic approach with the terrestrial snail Helix aspersa.

    Science.gov (United States)

    Gimbert, Frédéric; de Vaufleury, Annette; Douay, Francis; Scheifler, Renaud; Coeurdassier, Michaël; Badot, Pierre-Marie

    2006-09-01

    To enlarge the possibilities of using organisms of the soil fauna to assess the bioaccumulative potential of chemicals, the kinetic of soil cadmium (Cd) transfer to the terrestrial gastropod Helix aspersa was investigated under laboratory conditions during a long-term experiment (6 months). During the exposure phase (3 months), juvenile snails were subjected to three different concentrations of Cd spiked in artificial ISO soil (ISO 0, 20 and 100 mg Cd kg(-1)) and to a field soil (ME4) industrially contaminated by 20 mg Cd kg (-1). For both soils, internal steady-state Cd concentrations were reached in the viscera of the snails, the main storage organ for Cd, after 2 weeks of exposure whatever the Cd concentration in soil. The equilibrium concentrations in the viscera were 0.7 (+/-0.1), 11.3 (+/-2.4), 73.3 (+/-4.8) and 6.3 (+/-1.3) mg Cd kg(-1) dry mass for ISO 0, ISO 20, ISO 100 and ME4, respectively. During the depuration phase (3 months), from 0 to 52% of the accumulated Cd in the viscera were removed by excretion or relocation in the foot. However, the snails were not able to depurate down to initial concentrations. Data were modelled by integrating a specific growth rate constant into one-compartment toxicokinetic models. This allowed the calculation of Cd uptake rates that can be used as indicators of metal bioavailability. Since this parameter was found to be lower for snails exposed to the field soil ME4, we concluded that lower Cd bioavailability in this field soil was responsible of the lower transfer to the snails compared to the ISO 20 soil, even though they were polluted to similar extents. Internal validation showed that the toxicokinetic models could be applied for predictive purposes, promising for the development of a bioaccumulation directive for terrestrial environment.

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

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    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].

  6. 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

  7. Impairment of context memory by β-amyloid peptide in terrestrial snail

    Directory of Open Access Journals (Sweden)

    2008-09-01

    Full Text Available We examined influence of the β-amyloid peptide (25-35 neurotoxic fragment (βAP on Helix lucorum food-aversion learning. Testing with aversively conditioned carrot showed that 2, 5, and 14 days after training the βAP-injected group responded in a significantly larger number of cases and with a significantly smaller latency than the sham-injected control group. The results demonstrate that the amyloid peptide partially impairs the learning process. In an attempt to specify what component of memory is impaired we compared responses in a context in which the snails were aversively trained, and in a neutral context. It was found that the sham-injected learned snails significantly less frequently took the aversively conditioned food in the context in which the snails were shocked, while the βAP-injected snails remembered the aversive context 2 days after associative training, but were not able to distinguish two contexts 5, and 14 days after training. In a separate series of experiments a specific context was associated with electric shock, and changes in general responsiveness were tested in two contexts several days later. It was found that the βAP-injected snails significantly increased withdrawal responses in all tested contexts, while the sham-injected control animals selectively increased responsiveness only in the context in which they were reinforced with electric shocks. These results demonstrate that the β-amyloid peptide (25-35 interferes with the learning process, and may play a significant role in behavioral plasticity and memory by selectively impairing only one

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

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    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.

  9. 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

  10. Tradeoff between establishing an infection and killing the host: response of snails ( Physa acuta) to a gradient of trematode (Halipegus eccentricus) exposures.

    Science.gov (United States)

    Gustafson, K D; Bolek, M G

    2015-02-01

    Pond snails ( Physa acuta ) were exposed to a gradient (0, 1, 3, 5, 10, 15, 20, 25, 30, 35, 40, and 50) of trematode (Halipegus eccentricus) eggs and observed to determine egg dose effects on the survival of snails through the prepatent period, snail reproduction, and the production of cercariae. The probability of snail survival through the prepatent period significantly decreased with increasing egg exposures, where the odds of snail survival was 0.94 per trematode egg. Similarly, the probability of snail reproduction significantly decreased with increasing egg exposures, where the odds of snail reproduction was 0.85 per trematode egg. In contrast, the probability of a snail shedding cercariae significantly increased with increasing egg exposures, where the odds of reaching a patent infection were 1.64 per trematode egg. However, snails shedding cercariae that were exposed to higher doses of trematode eggs tended to die sooner. Thus, there appears to be a tradeoff between infecting a snail and killing the host.

  11. Sanitary diagnosis in different snail breeding places in Colombia: main pathogen agents affecting the snail Helix aspersa (O.F. Muller, 1774 in every phase of its biological process

    Directory of Open Access Journals (Sweden)

    Felipe A. Moncada Reyes

    2007-12-01

    Full Text Available The snail culture is an activity that requires of investigative processes for his optimal development. In Colombia the advances documented on the subject are almost inexistent. Therefore, it is responsibility of the veterinary doctor to create studies that generate a real knowledge on topics as the disease prevention within the snail breeding place. This investigation tries to make a sanitary diagnosis in each phase of the biological cycle of the snail Helix aspersa (O.F. Muller, 1774 bred in captivity. It also determines how different environmental factors (temperature, humidity, altitude above sea level, etc., and different forms of handling can be or no implied in the presentation of any disease. Thus, it identifies and classifies the main pathogenic agents of the land Helix snails in different environmental conditions of regions appropriate for the snail culture in Colombia. This study also makes an analysis of nonparametric observations studies, by observing particular pathological cases, exposed or not, to different risk factors. They measure the prevalence of every disease after applying a survey epidemiologist of risks, determining the pathologies related to the presented symptomatology and carrying out a microbiological isolation of the main contained pathogenic agents in each snail breeding place. The most significant pathologies will be documented inside the snail breeding place, based on the analysis of results through associations, and the rates of incidence for each disease, the presented relative risk, and the main factors of risk will be determined. Finally, with suitable breeding practices established after this study, we can foresee the presence of these alterations in the production of the snail in Colombia.

  12. Proposal: Documenting freshwater snail and trematode parasite diversity in the Wheeler Refuge Complex: baseline inventories and implications for animal health

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This proposal has 3 main objectives: Objective 1: Create a baseline inventory of freshwater snails for the Wheeler Refuge Complex. Objective 2: Identify target areas...

  13. 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.

    2015-01-01

    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 snails infected with O. viverrini s.l. were significantly smaller (P 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. PMID:25918210

  14. Transforming growth factor beta-1 induces snail transcription factor in epithelial cell lines: mechanisms for epithelial mesenchymal transitions

    National Research Council Canada - National Science Library

    Peinado, Hector; Quintanilla, Miguel; Cano, Amparo

    2003-01-01

    .... We show here that transforming growth factor beta-1 (TGFbeta1) induces Snail expression in Madin-Darby canine kidney cells and triggers epithelial-mesenchymal transitions by a mechanism dependent on the MAPK signaling pathway...

  15. A new sperm agglutinin factor from marine snail Telescopium telescopium : An evaluation with goat (Capra hircus) cauda epididymal spermatozoa

    National Research Council Canada - National Science Library

    Maji, Samata; Datta, Uttam; Hembram, Manik Lal

    2010-01-01

    ...(s) on the physiology of sperm cells if any. Materials and Methods: A protein factor, SF50 was obtained from spermatheca/ ovotestis gland of marine snail Telescopium telescopium by precipitation with 50% ammonium sulfate...

  16. Monthly trematode infections of the snail Cerithideopsis (Cerithidea) californica at Carpinteria Salt Marsh, California USA, February 2012 to January 2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Each month (except March 2012), we collected detailed data on the infection status of intertidal snails from ten fixed sites as part of a broader effort to...

  17. Is the interspecific variation of body size of land snails correlated with rainfall in Israel and Palestine?

    Science.gov (United States)

    Hausdorf, Bernhard

    2006-11-01

    The hypothesis that body size of land snail species increases with aridity in Israel and Palestine because large snails lose relatively less water due to their lower surface to volume ratio has been investigated. Data on rainfall amplitudes of 84 land snail species in Israel and Palestine and on their body sizes were used to test for interspecific correlations between body size and rainfall. Four methods, means of body sizes in rainfall categories, the midpoint method, the across-species method, and a phylogenetically controlled analysis (CAIC) showed that there is no significant correlation between body size of land snail species and their rainfall amplitude in Israel and Palestine. The lack of an interspecific correlation between body size and rainfall amplitude may be the result of conflicting selective forces on body size.

  18. On the effect specificity of accessory gland products transferred by the love-dart of land snails

    National Research Council Canada - National Science Library

    Lodi, Monica; Koene, Joris M

    2016-01-01

    .... These effects are mainly well documented for separate-sexed species. In simultaneous hermaphrodites, one of the most peculiar examples of transfer of such substances is via stabbing a so-called love-dart in land snails...

  19. Evaluation of different methods for the experimental infection of the land snail Helix aspersa with Aelurostrongylus abstrusus lungworm

    National Research Council Canada - National Science Library

    Napoli, Ettore; Falsone, Luigi; Gaglio, Gabriella; Colella, Vito; Otranto, Domenico; Giannetto, Salvatore; Brianti, Emanuele

    2016-01-01

    .... The land snail Helix aspersa (syn. Cornu aspersum), an intermediate host of feline lungworms Aelurostrongylus abstrusus and Troglostrongylus brevior, is adopted to produce infective stages of those nematodes in laboratory condition...

  20. THE BIOCIDE TRIBUTYLTIN REDUCES THE RETENTION OF TESTOSTERONE AS FATTY ACID ESTERS IN THE MUD SNAIL (ILYANASSA OBSOLETA)

    Science.gov (United States)

    ABSTRACT Imposex, the development of male sex characteristics by female gonochoristic snails, has been causally associated with exposure to the ubiquitous environmental contaminant tributyltin (TBT). Documentation of imposex distribution indicates that this masculinizat...

  1. Invasiveness does not predict impact: response of native land snail communities to plant invasions in riparian habitats

    Czech Academy of Sciences Publication Activity Database

    Horáčková, J.; Juřičková, L.; Šizling, A. L.; Jarošík, Vojtěch; Pyšek, Petr

    2014-01-01

    Roč. 9, č. 9 (2014), s. 1-10, e108296 E-ISSN 1932-6203 Institutional support: RVO:67985939 Keywords : plant invasions * land snails * impact Subject RIV: EF - Botanics Impact factor: 3.234, year: 2014

  2. Adaptive Changes in the Vestibular System of Land Snail to a 30-Day Spaceflight and Readaptation on Return to Earth

    Directory of Open Access Journals (Sweden)

    Nikolay Aseyev

    2017-11-01

    Full Text Available The vestibular system receives a permanent influence from gravity and reflexively controls equilibrium. If we assume gravity has remained constant during the species' evolution, will its sensory system adapt to abrupt loss of that force? We address this question in the land snail Helix lucorum exposed to 30 days of near weightlessness aboard the Bion-M1 satellite, and studied geotactic behavior of postflight snails, differential gene expressions in statocyst transcriptome, and electrophysiological responses of mechanoreceptors to applied tilts. Each approach revealed plastic changes in the snail's vestibular system assumed in response to spaceflight. Absence of light during the mission also affected statocyst physiology, as revealed by comparison to dark-conditioned control groups. Readaptation to normal tilt responses occurred at ~20 h following return to Earth. Despite the permanence of gravity, the snail responded in a compensatory manner to its loss and readapted once gravity was restored.

  3. Adaptive Changes in the Vestibular System of Land Snail to a 30-Day Spaceflight and Readaptation on Return to Earth.

    Science.gov (United States)

    Aseyev, Nikolay; Vinarskaya, Alia Kh; Roshchin, Matvey; Korshunova, Tatiana A; Malyshev, Aleksey Yu; Zuzina, Alena B; Ierusalimsky, Victor N; Lemak, Maria S; Zakharov, Igor S; Novikov, Ivan A; Kolosov, Peter; Chesnokova, Ekaterina; Volkova, Svetlana; Kasianov, Artem; Uroshlev, Leonid; Popova, Yekaterina; Boyle, Richard D; Balaban, Pavel M

    2017-01-01

    The vestibular system receives a permanent influence from gravity and reflexively controls equilibrium. If we assume gravity has remained constant during the species' evolution, will its sensory system adapt to abrupt loss of that force? We address this question in the land snail Helix lucorum exposed to 30 days of near weightlessness aboard the Bion-M1 satellite, and studied geotactic behavior of postflight snails, differential gene expressions in statocyst transcriptome, and electrophysiological responses of mechanoreceptors to applied tilts. Each approach revealed plastic changes in the snail's vestibular system assumed in response to spaceflight. Absence of light during the mission also affected statocyst physiology, as revealed by comparison to dark-conditioned control groups. Readaptation to normal tilt responses occurred at ~20 h following return to Earth. Despite the permanence of gravity, the snail responded in a compensatory manner to its loss and readapted once gravity was restored.

  4. Distribution and mapping of the snail Cerithideopsis (Cerithidea) californica at Carpinteria Salt Marsh, California USA, June to August 2012

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — We collected detailed spatial data on the density and size distribution of intertidal snails as part of a broader effort to understand food webs in California...

  5. Monthly densities of the snail Cerithideopsis (Cerithidea) californica at Carpinteria Salt Marsh, California USA, February 2012 to January 2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Each month (except March 2012), we collected detailed data on the density, size distribution, and infection status of intertidal snails from ten fixed sites as part...

  6. Transforming Growth Factor-β Promotes Liver Tumorigenesis in Mice via Up-regulation of Snail.

    Science.gov (United States)

    Moon, Hyuk; Ju, Hye-Lim; Chung, Sook In; Cho, Kyung Joo; Eun, Jung Woo; Nam, Suk Woo; Han, Kwang-Hyub; Calvisi, Diego F; Ro, Simon Weonsang

    2017-11-01

    Transforming growth factor beta (TGF-β) suppresses early stages of tumorigenesis, but also contributes to migration and metastasis of cancer cells. A large number of human tumors contain mutations that inactivate its receptors, or downstream proteins such as Smad transcription factors, indicating that the TGF-β signaling pathway prevents tumor growth. We investigated the effects of TGF-β inhibition on liver tumorigenesis in mice. C57BL/6 mice received hydrodynamic tail-vein injections of transposons encoding HRAS G12V and a short hairpin RNA (shRNA) to down-regulate p53, or those encoding HRAS G12V and MYC, or those encoding HRAS G12V and TAZ S89A , to induce liver tumor formation; mice were also given injections of transposons encoding SMAD7 or shRNA against SMAD2, SMAD3, SMAD4, or SNAI1 (Snail), with or without ectopic expression of Snail. Survival times were compared, and livers were weighted and examined for tumors. Liver tumor tissues were analyzed by quantitative reverse-transcription PCR, RNA sequencing, immunoblots, and immunohistochemistry. We analyzed gene expression levels in human hepatocellular carcinoma samples deposited in The Cancer Genome Atlas. A cell proliferation assay was performed using human liver cancer cell lines (HepG2 and Huh7) stably expressing Snail or shRNA against Snail. TGF-β inhibition via overexpression of SMAD7 (or knockdown of SMAD2, SMAD3, or SMAD4) consistently reduced formation and growth of liver tumors in mice that expressed activated RAS plus shRNA against p53, or in mice that expressed activated RAS and TAZ. TGF-β signaling activated transcription of the Snail gene in liver tumors induced by HRAS G12V and shRNA against p53, and by activated RAS and TAZ. Knockdown of Snail reduced liver tumor formation in both tumor models. Ectopic expression of Snail restored liver tumorigenesis suppressed by disruption of TGF-β signaling. In human hepatocellular carcinoma, Snail expression correlated with TGF-β activation. Ectopic

  7. Food Utilisation in a Laboratory Colony of the Giant African Land Snail, Archachatina marginata (Swainson) (Pulmonata: Achatinidae)

    OpenAIRE

    Rosemary I. Egonmwan

    2007-01-01

    This study investigates food consumption by juveniles and adults of the edible giant land snail Archachatina marginata under laboratory conditions. In one experiment, the snails were fed weekly from hatching for 13 months with weighed amounts of lettuce (Lactuca sativa), carrot (Daucus carota), potato (Solanum tuberosum), apple (Malus pumila), and calcium. Another group of 2-month-old A. marginata ovum was fed singly for 3 days on each of the test food items. The results show that, when given...

  8. Endogenous growth factor stimulation of hemocyte proliferation induces resistance to Schistosoma mansoni challenge in the snail host.

    Science.gov (United States)

    Pila, Emmanuel A; Gordy, Michelle A; Phillips, Valerie K; Kabore, Alethe L; Rudko, Sydney P; Hanington, Patrick C

    2016-05-10

    Digenean trematodes are a large, complex group of parasitic flatworms that infect an incredible diversity of organisms, including humans. Larval development of most digeneans takes place within a snail (Gastropoda). Compatibility between snails and digeneans is often very specific, such that suitable snail hosts define the geographical ranges of diseases caused by these worms. The immune cells (hemocytes) of a snail are sentinels that act as a crucial barrier to infection by larval digeneans. Hemocytes coordinate a robust and specific immunological response, participating directly in parasite killing by encapsulating and clearing the infection. Hemocyte proliferation and differentiation are influenced by unknown digenean-specific exogenous factors. However, we know nothing about the endogenous control of hemocyte development in any gastropod model. Here, we identify and functionally characterize a progranulin [Biomphalaria glabrata granulin (BgGRN)] from the snail B. glabrata, a natural host for the human blood fluke Schistosoma mansoni Granulins are growth factors that drive proliferation of immune cells in organisms, spanning the animal kingdom. We demonstrate that BgGRN induces proliferation of B. glabrata hemocytes, and specifically drives the production of an adherent hemocyte subset that participates centrally in the anti-digenean defense response. Additionally, we demonstrate that susceptible B. glabrata snails can be made resistant to infection with S. mansoni by first inducing hemocyte proliferation with BgGRN. This marks the functional characterization of an endogenous growth factor of a gastropod mollusc, and provides direct evidence of gain of resistance in a snail-digenean infection model using a defined factor to induce snail resistance to infection.

  9. Lysozyme-like activity in eggs and in some tissues of land snails Helix aspersa maxima and Achatina achatina.

    Science.gov (United States)

    Fiołka, Marta J; Witkowski, Andrzej

    2004-01-01

    Antibacterial lysozyme-like activity against Micrococcus luteus in eggs and some tissues of snails Helix aspers maxima and Achatina achatina was detected in a turbidimetric standard assay. The bacteriolytic activity in Helix aspersa maxima was higher than in Achatina achatina. After the application of the bioautography technique, several lytic zones of Micrococcus luteus were observed in both studied species. Electrophoresis in denaturing conditions followed by immunodetection of lysozyme using EWL antibodies indicated the presence of several lysozyme forms in the tested snails.

  10. Evaluation of different methods for the experimental infection of the land snail Helix aspersa with Aelurostrongylus abstrusus lungworm.

    Science.gov (United States)

    Napoli, Ettore; Falsone, Luigi; Gaglio, Gabriella; Colella, Vito; Otranto, Domenico; Giannetto, Salvatore; Brianti, Emanuele

    2016-07-30

    The laboratory maintenance of parasitic life cycles is crucial to support research in many fields of parasitology. The land snail Helix aspersa (syn. Cornu aspersum), an intermediate host of feline lungworms Aelurostrongylus abstrusus and Troglostrongylus brevior, is adopted to produce infective stages of those nematodes in laboratory condition. The aim of this study was to compare the most common methods of experimental infection of H. aspersa with first stage larvae (L1) of A. abstrusus (i.e., contact of the snail foot with the L1) with the injection of these larvae in the foot of the snail, instrumental to reduce the infection time and to maximize the output of third-stage larvae (L3). Three groups (i.e., A, B, C) of 15 H. aspersa snails were infected with L1 of A. abstrusus (n=250 for each snail), whereas a fourth group (group D) was not infected (control). Snails were individually placed for 48h on a microfilm containing L1 (group A), on a potato slice previously irrigated with a suspension of L1 (group B), or they were inoculated by injection of L1 in the posterior-ventral portion of the foot (group C). Eighteen days after the infection all snails were analyzed and tissues were digested to recover L3. No difference in mortality rate was recorded among snail groups and the mean number of retrieved L3 was significantly larger in group C (71.5±52.9) compared to group B (38.2±44.9; p=0.0161) and group A (19±23.3; paspersa proved to be a fast, easy to apply and effective method, resulting in the largest number of infective larvae retrieved. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Distribution, habitats and role as intermediate host of the freshwater snail, Bulinus forskalii, in South Africa

    OpenAIRE

    K. N. de Kock; C.T. Wolmarans

    2005-01-01

    This paper focuses on the geographical distribution and habitats of Bulinus forskalii, the snail intermediate host of the conical fluke of equids, Gastrodiscus aegyptiacus as reflected by the 1 209 samples in the database of the National Freshwater Snail Collection of South Africa. The 362 different loci on record represent an extensive distribution in KwaZulu-Natal Province, the Limpopo Province, the coastal areas of the Eastern Cape Province and the south-eastern part of the North Wes...

  12. 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.

  13. Expression and localization of transcription factors SNAIL and SLUG in mouse ovaries and pre-implantation embryos.

    Science.gov (United States)

    Guo, Cui; Meng, Xiaoqian; Bai, Jing; Chen, Cheng; Liu, Tao; Liu, Shuzhen; Zhang, Cong; Li, Wei-Ping

    2014-11-01

    SNAIL and SLUG are zinc-finger transcription factors that participate in the regulation of cell division, cell survival, mesoderm formation and epithelial-to-mesenchymal transition. We investigate the expression of SNAIL and SLUG during follicular maturation, ovulation and luteinization in the ovaries of both neonatal mice and gonadotropin-induced immature mice. Furthermore, we examine the expression and localization of these transcription factors during early embryonic cleavage. Our data demonstrate that both SNAIL and SLUG are present in the epithelial cells of the ovarian surface in immature mice. SNAIL is first evident in the interstitial cells and theca cells by postnatal day (PD) 6 and then appears in the oocytes by PD 8, remaining at a constant expression level for all stages studied thereafter. SLUG is expressed in oocytes as early as PD 1. Its expression also increases with the development of the follicles in theca and interstitial cells but not in granulosa cells. In gonadotropin-induced immature mice, both SNAIL and SLUG are expressed in the corpora lutea. During early embryo cleavage, SNAIL occurs in the nucleus and cytoplasm of the majority of the embryo, excluding the nucleolus from the germinal vesicle breakdown (GVBD) to the 8-cell stage and is then localized in the cytoplasm during the morula stage and in the nucleus during the blastocyst stage. SLUG has an identical expression pattern as SNAIL from GVBD until the morula stage, except that it is localized in the cytoplasm during the blastocyst stage. Taken together, these different localization patterns suggest that SNAIL and SLUG probably play important roles during follicular development, luteinization and early embryonic development.

  14. The clinical significance of snail protein expression in gastric cancer: a meta-analysis.

    Science.gov (United States)

    Chen, Xiaoya; Li, Jinjun; Hu, Ling; Yang, William; Lu, Lili; Jin, Hongyan; Wei, Zexiong; Yang, Jack Y; Arabnia, Hamid R; Liu, Jun S; Yang, Mary Qu; Deng, Youping

    2016-07-25

    Snail is a typical transcription factor that could induce epithelial-mesenchymal transition (EMT) and cancer progression. There are some related reports about the clinical significance of snail protein expression in gastric cancer. However, the published results were not completely consistent. This study was aimed to investigate snail expression and clinical significance in gastric cancer. A systematic review of PubMed, CNKI, Weipu, and Wanfang database before March 2015 was conducted. We established an inclusion criterion according to subjects, method of detection, and results evaluation of snail protein. Meta-analysis was conducted using RevMan4.2 software. And merged odds ratio (OR) and 95 % CI (95 % confidence interval) were calculated. Also, forest plots and funnel plot were used to assess the potential of publication bias. A total of 10 studies were recruited. The meta-analysis was conducted to evaluate the positive rate of snail protein expression. OR and 95 % CI for different groups were listed below: (1) gastric cancer and para-carcinoma tissue [OR = 6.15, 95 % CI (4.70, 8.05)]; (2) gastric cancer and normal gastric tissue [OR = 17.00, 95 % CI (10.08, 28.67)]; (3) non-lymph node metastasis and lymph node metastasis [OR = 0.40, 95 % CI (0.18, 0.93)]; (4) poor differentiated cancer, highly differentiated cancer, and moderate cancer [OR = 3.34, 95 % CI (2.22, 5.03)]; (5) clinical stage TI + TII and stage TIII + TIV [OR = 0.38, 95 % CI (0.23, 0.60)]; (6) superficial muscularis and deep muscularis [OR = 0.18, 95 % CI (0.11, 0.31)]. Our results indicated that the increase of snail protein expression may play an important role in the carcinogenesis, progression, and metastasis of gastric cancer. And this result might provide instruction for the diagnosis, therapy, and prognosis of gastric cancer.

  15. Copper desorption in flooded agricultural soils and toxicity to the Florida apple snail (Pomacea paludosa): implications in Everglades restoration.

    Science.gov (United States)

    Hoang, Tham C; Rogevich, Emily C; Rand, Gary M; Gardinali, Piero R; Frakes, Robert A; Bargar, Timothy A

    2008-07-01

    Copper (Cu) desorption and toxicity to the Florida apple snail were investigated from soils obtained from agricultural sites acquired under the Comprehensive Everglades Restoration Plan. Copper concentrations in 11 flooded soils ranged from 5 to 234 mg/kg on day 0 and from 6.2 to 204 mg/kg on day 28 (steady-state). The steady-state Cu concentration in overlying water ranged from 9.1 to 308.2 microg/L. In a 28-d growth study, high mortality in snails occurred within 9 to 16 d in two of three soil treatments tested. Growth of apple snails over 28 d was affected by Cu in these two treatments. Tissue Cu concentrations by day 14 were 12-23-fold higher in snails exposed to the three soil treatments compared to controls. The endangered Florida snail kite and its main food source, the Florida apple snail, may be at risk from Cu exposure in these managed agricultural soil-water ecosystems.

  16. Implications of Changing Temperatures on the Growth, Fecundity and Survival of Intermediate Host Snails of Schistosomiasis: A Systematic Review.

    Science.gov (United States)

    Kalinda, Chester; Chimbari, Moses; Mukaratirwa, Samson

    2017-01-13

    Climate change has been predicted to increase the global mean temperature and to alter the ecological interactions among organisms. These changes may play critical roles in influencing the life history traits of the intermediate hosts (IHs). This review focused on studies and disease models that evaluate the potential effect of temperature rise on the ecology of IH snails and the development of parasites within them. The main focus was on IH snails of schistosome parasites that cause schistosomiasis in humans. A literature search was conducted on Google Scholar, EBSCOhost and PubMed databases using predefined medical subject heading terms, Boolean operators and truncation symbols in combinations with direct key words. The final synthesis included nineteen published articles. The studies reviewed indicated that temperature rise may alter the distribution, optimal conditions for breeding, growth and survival of IH snails which may eventually increase the spread and/or transmission of schistosomiasis. The literature also confirmed that the life history traits of IH snails and their interaction with the schistosome parasites are affected by temperature and hence a change in climate may have profound outcomes on the population size of snails, parasite density and disease epidemiology. We concluded that understanding the impact of temperature on the growth, fecundity and survival of IH snails may broaden the knowledge on the possible effects of climate change and hence inform schistosomiasis control programmes.

  17. The alien invasive land snail Theba pisana in the West Coast National Park: Is there cause for concern?

    Directory of Open Access Journals (Sweden)

    Lizelle J. Odendaal

    2008-05-01

    Full Text Available The distribution, abundance, size distribution and diurnal activity patterns of invasive land snails, Theba pisana, in the West Coast National Park (WCNP, South Africa, were investigated. The park was divided into 1 km2 grids, within each of which five 1 m2 quadrat counts of live snails were recorded. Of 106 grids sampled, 19% contained live snails. The average density of snails was 4.04 m-2 ± 24.9, significantly lower than in disturbed habitats adjacent to the park (57 m-2 ± 96.25, but very high densities were recorded at two sites. Snails were most abundant along roadsides and densities decreased dramatically with distance from roads. T. pisana in the WCNP appear to have an annual lifecycle, breeding in autumn to winter and growing to adult size of about 14 mm diameter by the end of the following summer. Snails were observed on a wide variety of endemic and introduced plant species and appeared to have a catholic diet. They are active mostly at night and especially during periods of high humidity, irrespective of temperature. Given the very high densities that T. pisana can attain at some sites, plus their apparently catholic feeding habits, their potential impact on the vegetation of the park is cause for concern and should be further investigated. Control of the main colonies should also be considered.

  18. Implications of Changing Temperatures on the Growth, Fecundity and Survival of Intermediate Host Snails of Schistosomiasis: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Chester Kalinda

    2017-01-01

    Full Text Available Climate change has been predicted to increase the global mean temperature and to alter the ecological interactions among organisms. These changes may play critical roles in influencing the life history traits of the intermediate hosts (IHs. This review focused on studies and disease models that evaluate the potential effect of temperature rise on the ecology of IH snails and the development of parasites within them. The main focus was on IH snails of schistosome parasites that cause schistosomiasis in humans. A literature search was conducted on Google Scholar, EBSCOhost and PubMed databases using predefined medical subject heading terms, Boolean operators and truncation symbols in combinations with direct key words. The final synthesis included nineteen published articles. The studies reviewed indicated that temperature rise may alter the distribution, optimal conditions for breeding, growth and survival of IH snails which may eventually increase the spread and/or transmission of schistosomiasis. The literature also confirmed that the life history traits of IH snails and their interaction with the schistosome parasites are affected by temperature and hence a change in climate may have profound outcomes on the population size of snails, parasite density and disease epidemiology. We concluded that understanding the impact of temperature on the growth, fecundity and survival of IH snails may broaden the knowledge on the possible effects of climate change and hence inform schistosomiasis control programmes.

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

    Directory of Open Access Journals (Sweden)

    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.

  20. Schistosoma mansoni: changes in the albumen gland of Biomphalaria glabrata snails selected for nonsusceptibility to the parasite.

    Science.gov (United States)

    Cousin, C; Ofori, K; Acholonu, S; Miller, A; Richards, C; Lewis, F; Knight, M

    1995-12-01

    The LAC-line strain of the snail Biomphalaria glabrata has very low susceptibility to the parasite Schistosoma mansoni and a very low reproductive potential. Upon examination of the reproductive tract of these snails, light and electron microscopy revealed obvious abnormalities in the albumen gland. Secretory cells that are normally cuboidal in susceptible NMRI (F0) snails were squamous in LAC-line snails. These LAC-line cells contained small secretory granules and negligible rough endoplasmic reticulum and Golgi, compared to large granules and an extensive array of both organelles in F0 albumen gland cells. Comparative analyses of soluble protein extracts of F0 and LAC-line albumen glands showed several qualitative differences. Among the most prominent was an 18-kDa protein in F0 snails that was remarkably reduced in the soluble protein extracts of LAC-line snails. Also, metabolic incorporation of [35S]-methionine was impaired in LAC-line albumen glands. Whether these albumen gland changes are caused by decreased susceptibility to parasitism is yet to determined.