390 research outputs found
Influence de quelques facteurs du milieu sur la fécondité de Biomphalaria glabrata (Say, 1818) (Mollusca, Pulmonata) dans les conditions du laboratoire
A Stylistic Analysis Using Multivariate Statistics of Oneota Pottery from the Upper Mississippi, Blue Earth, and St. Croix River Valleys
Pottery is one of the most abundant artifact types recovered from late pre-contact habitations sites in the upper Midwest. As a material with inherent plasticity, pottery reflects changes in people\u27s preferences and traditions in aspects of its form and design quickly through time and space. Analyzing different facets of pottery has the ability to provide extensive information about people in the past: their resource utilization, technology, traditions, economic exchange, regional interaction, ideology, and or group identity. Yet, a significant challenge in pottery analysis is deriving comprehensive and testable conclusions in terms of types and styles that reflect patterned cultural behavior and the changing nature of the archeological record. In order to infer aspects of patterned behavior, archeologists must be clear about the temporal and spatial boundaries of their classifications as well as qualitative and quantitative parameters of vessel morphology and decoration.
The typologies created throughout the 20th century to describe Oneota pottery from the Upper Mississippi, Blue Earth, and St. Croix River valleys were not explained in great detail and need to be reevaluated. Past classifications of Oneota pottery from these geographical locations were too inclusive, using very few attributes of vessel form and design and little to no quantitative parameters to discern what was or was not included in the defined types. Also, archeologists often used small rim, decorated body, etc., sherds to establish their types, but such small pieces do not provide a sound representation of pottery vessels\u27 morphological form or overall decorative design. In addition, these past types no longer reflect the current state of the archeological record given recently excavated material.
This study focuses on the morphological and decorative aspects of late pre-contact Oneota pottery from the Upper Mississippi, Blue Earth, St. Croix River valleys. This research reevaluates the past typological classifications of Oneota pottery in southern Minnesota and parts of western Wisconsin using quantitative and qualitative data acquired from measuring detailed aspects of form and design of vessels and vessel segments. In addition, it uses different aspects of descriptive, exploratory, and multivariate statistical analyses to create typological classifications that are comprehensive in aspects of overall form and design as well as testable and falsifiable
Interaction between the Intermediate Host of Schistosomiasis in Brazil Biomphalaria glabrata (Planorbidae) and a Possible Competitor Melanoides tuberculata (Thiaridae): I. Laboratory Experiments
La saison sèche en Guadeloupe et ses conséquences sur la démographie des mollusques dans les biotopes A Biomphalaria glabrata (say, 1818), vecteur de la bilharziose intestinale
Resistance of some freshwater snails to drought has been studied in four seasonal ponds, one (temporary) stream and one « mangrove » area on the island of Guadeloupe, West Indies. In such locations a small percentage of the snail population is able to survive the dry season under the shelter of organic debris and rocks. Biomphalaria glabrata, the local intermediate host of human Rilharziasis, is less resistant to dessication than sympatric Eupera viridans, Biomphalaria schrammi, Drepanotrema lucidum and Ampullaria glauca. Physa marmorata, Drepanotrema kermatoides and Pleisiophysa granulata are even more sensitive to drought than Biomphalaria glabrata
Distribution and habitat preferences of the genus Biomphalaria (Gastropoda: Planorbidae) in Cuba
Life tables of freshwater snails of the genus Biomphalaria (B. glabrata, B. alexandrina, B. straminea) and of one of its competitors Melanoides tuberculata under laboratory conditions
International audienceLife tables of several strains of Biomphalariea glabrata, B. alexandreina and B. straminea have been established under laboratory conditions and compared with that of Malanoides tuberculata, a prosobranch snail used as a competitor of snail vectors of schistosomiasis in experiments of biological control. Results indicate a grat range of intraspecific and interspecific variation within the Biomphalaria and a quite distinct demographic strategy of M. tuberculata
Isolation, characterization and population-genetic analysis of microsatellite loci in the freshwater snail <i>Galba cubensis</i> (Lymnaeidae)
The freshwater snail Galba cubensis (Pfeiffer, 1839) has a large distribution in the Americas. Despite being an intermediate host of Fasciola hepatica - the trematode causing fasciolosis in livestock and humans - its population genetics have never been studied. We isolated and characterized 15 microsatellite loci in G. cubensis to evaluate its genetic diversity, population-genetic structure and mating system. We tested the microsatellite loci in 359 individuals from 13 populations of G. cubensis from Cuba, Guadeloupe, Martinique, Puerto Rico, Venezuela, Colombia and Ecuador. We also tested cross-amplification in three closely related species: G. truncatula, G. viator and G. neotropica. We found that G. cubensis has a similar population structure to other selfing lymnaeids that live in temporary habitats: low genetic diversity, large departure from Hardy-Weinberg equilibrium, marked population structure and high selfing rate. We found that seven and six loci amplified in G. truncatula and G. viator, respectively, and that all 15 loci amplified in G. neotropica. This last finding suggests a close relatedness between G. cubensis and G. neotropica, probably being conspecific and synonymous. This new set of microsatellite markers will be a useful tool to study the genetic diversity of this snail species across a large geographical range and, consequently, to understand the emergence and re-emergence of fasciolosis in the Americas.Centro de Estudios Parasitológicos y de VectoresFacultad de Ciencias Naturales y Muse
Bridging gaps in the molecular phylogeny of the Lymnaeidae (Gastropoda: Pulmonata), vectors of Fascioliasis
<p>Abstract</p> <p>Background</p> <p>Lymnaeidae snails play a prominent role in the transmission of helminths, mainly trematodes of medical and veterinary importance (<it>e.g</it>., <it>Fasciola </it>liver flukes). As this family exhibits a great diversity in shell morphology but extremely homogeneous anatomical traits, the systematics of Lymnaeidae has long been controversial. Using the most complete dataset to date, we examined phylogenetic relationships among 50 taxa of this family using a supermatrix approach (concatenation of the 16 S, ITS-1 and ITS-2 genes, representing 5054 base pairs) involving both Maximum Likelihood and Bayesian Inference.</p> <p>Results</p> <p>Our phylogenetic analysis demonstrates the existence of three deep clades of Lymnaeidae representing the main geographic origin of species (America, Eurasia and the Indo-Pacific region). This phylogeny allowed us to discuss on potential biological invasions and map important characters, such as, the susceptibility to infection by <it>Fasciola hepatica </it>and <it>F. gigantica</it>, and the haploid number of chromosomes (n). We found that intermediate hosts of <it>F. gigantica </it>cluster within one deep clade, while intermediate hosts of <it>F. hepatica </it>are widely spread across the phylogeny. In addition, chromosome number seems to have evolved from n = 18 to n = 17 and n = 16.</p> <p>Conclusion</p> <p>Our study contributes to deepen our understanding of Lymnaeidae phylogeny by both sampling at worldwide scale and combining information from various genes (supermatrix approach). This phylogeny provides insights into the evolutionary relationships among genera and species and demonstrates that the nomenclature of most genera in the Lymnaeidae does not reflect evolutionary relationships. This study highlights the importance of performing basic studies in systematics to guide epidemiological control programs.</p
Apparent competition through facilitation between Melanoides tuberculata and Biomphalaria glabrata and the control of schistosomiasis
Distribución actualizada de limneidos vectores de Fasciola hepatica e índice cercárico en la región Arequipa, Perú
Fasciolosis is a zoonotic disease caused by Fasciola hepatica, which is widely distributed in Peru and considered highly endemic in the Arequipa region. Despite this, records of lymnaeid snails in the area remain limited. This study aimed to identify lymnaeid vectors of F. hepatica and to determine their distribution across natural regions, along with their corresponding cercarial index (CI). Lymnaeid snails were manually collected from irrigation canals, wetlands, and other humid environments, identified by their small size and dextral coiling shell. A subset of 10–25 snails was immersed in water at 70°C for 30–40 seconds to facilitate soft tissue extraction. The soft bodies were then removed from the shells and preserved in 70% ethanol. Taxonomic identification was conducted at the Centre de Recherches insulaires et observatoire de L’environnement (CRIOBE), Université de Perpignan, France, based on morphological characteristics of the shell and soft body parts. Sampling locations were categorized according to natural regions: coast (≤2000 m.a.s.l.) and highlands (>2000 m.a.s.l.). Live lymnaeids were examined by compression under a compound microscope (40X and 100X magnification). The criterion for positivity was the presence of rediae and cercariae of F. hepatica. New distribution areas of lymnaeid snails were identified. On the coast, the species detected included Galba cubensis (primary vector) in the provinces of Caravelí, Camaná, Islay, and Arequipa; Pseudosuccinea columella (potential vector) in Caravelí; and G. schirazensis in Santa Rita de Siguas. In the highlands, G. truncatula was identified as the primary vector in the provinces of Caylloma, La Unión, Castilla, Condesuyos, and Arequipa. Cercarial indices were generally low, averaging 0.63% for the Arequipa region. In localities with positive vectors, the distribution was as follows: on the coast, G. cubensis in Vítor showed a CI of 2.13%; in the highlands, G. truncatula exhibited CI values of 1.20% in Huanca, 1.61% in Achoma, 2.63% in Maca, and 2.78% in Taurisma.La fasciolosis es una zoonosis causada por Fasciola hepatica, de amplia distribución en el Perú y particularmente endémica en Arequipa. En esta región, los reportes de limneidos son escasos. Se realizó el estudio en la región Arequipa, con el objetivo de identificar los limneidos vectores de F. hepatica, su distribución de acuerdo con la región natural y el índice cercárico (IC). Se colectaron limneidos, de forma manual en acequias, bofedales o lugares húmedos, reconocidos por su tamaño pequeño y su conchilla dextrógira. Una parte (10-25 caracoles) fue introducida en agua a 70 °C por 30-40 segundos. Posteriormente, se extrajo el cuerpo blando de la conchilla y esta fue fijada en etanol 70%. La identificación taxonómica basada en caracteres morfológicos de las partes blandas y conchilla fue realizada en el Centre de Recherches insulaires et observatoire de L´environnement (CRIOBE), Université de Perpignan, Francia. Las localidades se clasificaron según región natural: costa (hasta 2.000 m s. n. m.) y sierra (sobre 2.000 m s. n. m.). Los limneidos vivos fueron examinados por aplastamiento en microscopio compuesto. El criterio de positividad fue la observación de redias y cercarias compatibles con F. hepatica. Se detectaron nuevas áreas de distribución de limneidos. Las especies identificadas en la costa fueron Galba cubensis vector primario en las provincias de Caravelí, Camaná, Islay y Arequipa; Pseudosuccinea columella vector potencial en Caravelí y G. schirazensis en Santa Rita de Siguas. En la sierra se identificó a G. truncatula como vector primario en las provincias de Caylloma, La Unión, Castilla, Condesuyos y Arequipa. Los índices cercáricos en general fueron bajos con 0,63% para la región Arequipa y por localidades con vectores positivos distribuidos en la costa (G. cubensis) 2,13% en Vítor; y en la sierra (G. truncatula) en Huanca 1,20%, Achoma 1,61%, Maca 2,63% y Taurisma 2,78%
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