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Letteratura scientifica selezionata sul tema "Ecologie parasite"

Autore: Grafiati

Pubblicato: 5 ottobre 2024

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Articoli di riviste sul tema "Ecologie parasite"

MUÑOZ, G., A. S. GRUTTER e T. H. CRIBB. "Endoparasite communities of five fish species (Labridae: Cheilininae) from Lizard Island: how important is the ecology and phylogeny of the hosts?" Parasitology 132, n. 3 (7 dicembre 2005): 363–74. http://dx.doi.org/10.1017/s0031182005009133.

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The parasite community of animals is generally influenced by host physiology, ecology, and phylogeny. Therefore, sympatric and phylogenetically related hosts with similar ecologies should have similar parasite communities. To test this hypothesis we surveyed the endoparasites of 5 closely related cheilinine fishes (Labridae) from the Great Barrier Reef. They were Cheilinus chlorourus, C. trilobatus, C. fasciatus, Epibulus insidiator and Oxycheilinus diagramma. We examined the relationship between parasitological variables (richness, abundance and diversity) and host characteristics (body weight, diet and phylogeny). The 5 fishes had 31 parasite species with 9–18 parasite species per fish species. Cestode larvae (mostly Tetraphyllidea) were the most abundant and prevalent parasites followed by nematodes and digeneans. Parasites, body size and diet of hosts differed between fish species. In general, body weight, diet and host phylogeny each explained some of the variation in richness and composition of parasites among the fishes. The 2 most closely related species, Cheilinus chlorourus and C. trilobatus, had broadly similar parasites but the other fish species differed significantly in all variables. However, there was no all-encompassing pattern. This may be because different lineages of parasites may react differently to ecological variables. We also argue that adult parasites may respond principally to host diet. In contrast, larval parasite composition may respond both to host diet and predator-prey interactions because this is the path by which many parasites complete their life-cycles. Finally, variation in parasite phylogeny and parasite life-cycles among hosts likely increase the complexity of the system making it difficult to find all-encompassing patterns between host characteristics and parasites, particularly when all the species in rich parasite communities are considered.

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Marques, Livia Castro, e Dimitri Ramos Alves. "Ecologia da comunidade de metazoários parasitos do dourado, Coryphaena hippurus Linnaeus, 1758, (Osteichthyes: Coryphaenidae) do litoral do Estado do Rio de Janeiro, Brasil." Cadernos UniFOA 6, n. 16 (27 marzo 2017): 111. http://dx.doi.org/10.47385/cadunifoa.v6i16.1070.

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From April 2009 and July 2010, 68 specimens of common dolphinfish Coryphaena hippurus Linnaeus, 1758 (Osteichthyes: Coryphaenidae) collected from coast of the state of Rio de Janeiro (21-23° S, 41-45° W), were necropsied to study their infracommunities of metazoan parasites. Seventeen species of metazoan parasites were collected. All fish were parasitized by one or more metazoan. The digeneans were the majority of the specimens collected, with 90.7%. Dinurus tornatus (Rudolphi, 1819) was the dominant species with highest abundance, prevalence, frequency of dominance and mean relative dominance. The parasites species of C. hippurus showed a typical aggregate pattern of distribution. None metazoan parasites species showed correlation between total length and prevalence and parasite abundance. The metazoan parasite infracommunities C. hippurus showed dominance of endoparasites (digeneans) and no correlation between abundance and parasite species richness and the total length of the host.

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Ezenwa, Vanessa O., Elizabeth A. Archie, Meggan E. Craft, Dana M. Hawley, Lynn B. Martin, Janice Moore e Lauren White. "Host behaviour–parasite feedback: an essential link between animal behaviour and disease ecology". Proceedings of the Royal Society B: Biological Sciences 283, n. 1828 (13 aprile 2016): 20153078. http://dx.doi.org/10.1098/rspb.2015.3078.

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Animal behaviour and the ecology and evolution of parasites are inextricably linked. For this reason, animal behaviourists and disease ecologists have been interested in the intersection of their respective fields for decades. Despite this interest, most research at the behaviour–disease interface focuses either on how host behaviour affects parasites or how parasites affect behaviour, with little overlap between the two. Yet, the majority of interactions between hosts and parasites are probably reciprocal, such that host behaviour feeds back on parasites and vice versa. Explicitly considering these feedbacks is essential for understanding the complex connections between animal behaviour and parasite ecology and evolution. To illustrate this point, we discuss how host behaviour–parasite feedbacks might operate and explore the consequences of feedback for studies of animal behaviour and parasites. For example, ignoring the feedback of host social structure on parasite dynamics can limit the accuracy of predictions about parasite spread. Likewise, considering feedback in studies of parasites and animal personalities may provide unique insight about the maintenance of variation in personality types. Finally, applying the feedback concept to links between host behaviour and beneficial, rather than pathogenic, microbes may shed new light on transitions between mutualism and parasitism. More generally, accounting for host behaviour–parasite feedbacks can help identify critical gaps in our understanding of how key host behaviours and parasite traits evolve and are maintained.

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Auld, Stuart K. J. R., Catherine L. Searle e Meghan A. Duffy. "Parasite transmission in a natural multihost–multiparasite community". Philosophical Transactions of the Royal Society B: Biological Sciences 372, n. 1719 (13 marzo 2017): 20160097. http://dx.doi.org/10.1098/rstb.2016.0097.

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Understanding the transmission and dynamics of infectious diseases in natural communities requires understanding the extent to which the ecology, evolution and epidemiology of those diseases are shaped by alternative hosts. We performed laboratory experiments to test how parasite spillover affected traits associated with transmission in two co-occurring parasites: the bacterium Pasteuria ramosa and the fungus Metschnikowia bicuspidata . Both parasites were capable of transmission from the reservoir host ( Daphnia dentifera ) to the spillover host ( Ceriodaphnia dubia ), but this occurred at a much higher rate for the fungus than the bacterium. We quantified transmission potential by combining information on parasite transmission and growth rate, and used this to compare parasite fitness in the two host species. For both parasites, transmission potential was lower in the spillover host. For the bacterium, virulence was higher in the spillover host. Transmission back to the original host was high for both parasites, with spillover influencing transmission rate of the fungus but not the bacterium. Thus, while inferior, the spillover host is not a dead-end for either parasite. Overall, our results demonstrate that the presence of multiple hosts in a community can have important consequences for disease transmission, and host and parasite fitness. This article is part of the themed issue ‘Opening the black box: re-examining the ecology and evolution of parasite transmission’.

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Horn, Collin J., e Lien T. Luong. "Proximity to parasites reduces host fitness independent of infection in a Drosophila–Macrocheles system". Parasitology 145, n. 12 (13 marzo 2018): 1564–69. http://dx.doi.org/10.1017/s0031182018000379.

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AbstractParasites are known to have direct negative effects on host fitness; however, the indirect effects of parasitism on host fitness sans infection are less well understood. Hosts undergo behavioural and physiological changes when in proximity to parasites. Yet, there is little experimental evidence showing that these changes lead to long-term decreases in host fitness. We aimed to determine if parasite exposure affects host fitness independent of contact, because current approaches to parasite ecology may underestimate the effect of parasites on host populations. We assayed the longevity and reproductive output of Drosophila nigrospiracula exposed or not exposed to ectoparasitic Macrocheles subbadius. In order to preclude contact and infection, mites and flies were permanently separated with a mesh screen. Exposed flies had shorter lives and lower fecundity relative to unexposed flies. Recent work in parasite ecology has argued that parasite–host systems show similar processes as predator–prey systems. Our findings mirror the non-consumptive effects observed in predator–prey systems, in which prey species suffer reduced fitness even if they never come into direct contact with predators. Our results support the perspective that there are analogous effects in parasite–host systems, and suggest new directions for research in both parasite ecology and the ecology of fear.

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Sarabian, Cecile, Val Curtis e Rachel McMullan. "Evolution of pathogen and parasite avoidance behaviours". Philosophical Transactions of the Royal Society B: Biological Sciences 373, n. 1751 (4 giugno 2018): 20170256. http://dx.doi.org/10.1098/rstb.2017.0256.

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All free-living animals are subject to intense selection pressure from parasites and pathogens resulting in behavioural adaptations that can help potential hosts to avoid falling prey to parasites. This special issue on the evolution of parasite avoidance behaviour was compiled following a Royal Society meeting in 2017. Here we have assembled contributions from a wide range of disciplines including genetics, ecology, parasitology, behavioural science, ecology, psychology and epidemiology on the disease avoidance behaviour of a wide range of species. Taking an interdisciplinary and cross-species perspective allows us to sketch out the strategies, mechanisms and consequences of parasite avoidance and to identify gaps and further questions. Parasite avoidance strategies must include avoiding parasites themselves and cues to their presence in conspecifics, heterospecifics, foods and habitat. Further, parasite avoidance behaviour can be directed at constructing parasite-retardant niches. Mechanisms of parasite avoidance behaviour are generally less well characterized, though nematodes, rodents and human studies are beginning to elucidate the genetic, hormonal and neural architecture that allows animals to recognize and respond to cues of parasite threat. While the consequences of infection are well characterized in humans, we still have much to learn about the epidemiology of parasites of other species, as well as the trade-offs that hosts make in parasite defence versus other beneficial investments like mating and foraging. Finally, in this overview we conclude that it is legitimate to use the word ‘ disgust' to describe parasite avoidance systems, in the same way that ‘fear' is used to describe animal predator avoidance systems. Understanding disgust across species offers an excellent system for investigating the strategies, mechanisms and consequences of behaviour and could be a vital contribution towards the understanding and conservation of our planet's ecosystems. This article is part of the Theo Murphy meeting issue ‘Evolution of pathogen and parasite avoidance behaviours'.

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Grenfell, B. T., e F. M. D. Gulland. "Introduction: Ecological impact of parasitism on wildlife host populations". Parasitology 111, S1 (gennaio 1995): S3—S14. http://dx.doi.org/10.1017/s0031182000075788.

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The study of parasite population dynamics has been one of the major developments in ecology over the last 15 years (Kennedy, 1975). The seminal articles of Crofton (1971) and Anderson & May (1978, 1979; May & Anderson, 1978, 1979) began this process by illustrating the potential role of parasites in regulating or destabilizing the dynamics of wildlife host populations. Since then, a variety of empirical and theoretical studies (reviewed by Grenfell & Dobson, 1995) have explored the role of parasites in natural populations. In parallel with these population dynamical developments, a growing interest in the evolutionary ecology of parasites has also led to a large literature, examining the evolutionary impact of parasites and the importance of host-parasite coevolution (Hamilton, 1982; May & Anderson, 1990; Lively & Apanius, 1995; Read et al. 1995; Herre, this volume).

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Mahony, Kate E., Sharon A. Lynch, Xavier de Montaudouin e Sarah C. Culloty. "Extrinsic and intrinsic drivers of parasite prevalence and parasite species richness in a marine bivalve". PLOS ONE 17, n. 9 (26 settembre 2022): e0274474. http://dx.doi.org/10.1371/journal.pone.0274474.

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Parasite species richness is influenced by a range of drivers including host related factors (e.g. host size) and environmental factors (e.g. seawater temperature). However, identification of modulators of parasite species richness remains one of the great unanswered questions in ecology. The common cockle Cerastoderma edule is renowned for its diversity and abundance of parasites, yet drivers of parasite species richness in cockles have not been examined to investigate the association of both macro and microparasite communities. Using cockles as a model species, some of the key drivers of parasite prevalence and parasite species richness were investigated. Objectives of this 19-month survey were to determine the influence of the environment, host-parasite dynamics and parasite associations on parasite species richness and prevalence at two different geographic latitudes, chosen based on environmental differences. The highest parasite species richness was recorded in the northern sites, and this was potentially influenced by a range of interactions between the host, the pathogens and the environment. Parasite prevalence increased with host size and age, and parasite species richness increased with reduced salinity. A number of interactions between parasites, and between parasites and pathologies may be influencing parasite infection dynamics. New and concerning information is also presented regarding interactions between parasites and their environment. A number of parasites and potential pathogens (bacteria, Trichodina ciliates, metacercariae, trematode sporocysts) may be advantaged under climate change conditions (warming seas, increased precipitation), increasing disease incidence, which may prove detrimental not just for cockles, but for other bivalve species in the future.

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Walker, Josephine G., Michaela Plein, Eric R. Morgan e Peter A. Vesk. "Uncertain links in host–parasite networks: lessons for parasite transmission in a multi-host system". Philosophical Transactions of the Royal Society B: Biological Sciences 372, n. 1719 (13 marzo 2017): 20160095. http://dx.doi.org/10.1098/rstb.2016.0095.

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For many parasites, the full set of hosts that are susceptible to infection is not known, and this could lead to a bias in estimates of transmission. We used counts of individual adult parasites from historical parasitology studies in southern Africa to map a bipartite network of the nematode parasites of herbivore hosts that occur in Botswana. Bipartite networks are used in community ecology to represent interactions across trophic levels. We used a Bayesian hierarchical model to predict the full set of host–parasite interactions from existing data on parasitic gastrointestinal nematodes of wild and domestic ungulates given assumptions about the distribution of parasite counts within hosts, while accounting for the relative uncertainty of less sampled species. We used network metrics to assess the difference between the observed and predicted networks, and to explore the connections between hosts via their shared parasites using a host–host unipartite network projected from the bipartite network. The model predicts a large number of missing links and identifies red hartebeest, giraffe and steenbok as the hosts that have the most uncertainty in parasite diversity. Further, the unipartite network reveals clusters of herbivores that have a high degree of parasite sharing, and these clusters correspond closely with phylogenetic distance rather than with the wild/domestic boundary. These results provide a basis for predicting the risk of cross-species transmission of nematode parasites in areas where livestock and wildlife share grazing land. This article is part of the themed issue ‘Opening the black box: re-examining the ecology and evolution of parasite transmission’.

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Più fonti

Tesi sul tema "Ecologie parasite"

Garnier, Romain. "Ecologie évolutive de la transmission maternelle d'anticorps". Thesis, Montpellier, SupAgro, 2011. http://www.theses.fr/2011NSAM0045/document.

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Chez les vertébrés, la réponse immunitaire acquise représente un mécanisme sophistiqué de réponse face aux parasites dont l‟une des particularités est la possibilité qu‟il offre aux mères de transférer certains de ses effecteurs à leurs nouveau-nés. Pourtant, malgré un intérêt croissant pour les effets maternels, les déterminants écologiques et évolutifs du transfert d‟anticorps maternels n‟ont pas encore été beaucoup étudiés. L‟analyse d‟un cadre théorique spécialement développé pour inclure le transfert transgénérationnel d‟immunité montre que l‟évolution de la capacité à transférer une immunité temporaire aux jeunes dépend des caractéristiques de l‟hôte et du parasite. En particulier, l‟augmentation de l‟espérance de vie de l‟hôte favorise l‟évolution de réponses immunitaires acquises, et la protection conférée par ces réponses est aussi supposée durer plus longtemps chez les hôtes longévifs. En accord avec cette prédiction, une étude de vaccination transgénérationnelle chez une espèce d‟oiseau de mer longévive a permis de mettre en évidence une demi-vie des anticorps maternels particulièrement longue. Les conditions sociales sont aussi un élément clé, et chez une espèce de mammifère, j‟ai pu montrer qu‟elles permettent un élargissement du répertoire d‟anticorps maternels. Le transfert d‟anticorps maternels est aussi à même de modifier les dynamiques épidémiologiques et pourrait présenter un atout non négligeable si la vaccination était utilisée en conservation. Enfin, ce mécanisme pourrait être mis à profit pour estimer l‟exposition des mères, et ainsi inférer la dispersion entre différentes zones d‟habitat
In vertebrate species, acquired immune response represents a sophisticated protection mechanism against parasites that has the particularity of enabling mothers to transmit part of its effectors to their newborns. Yet, despite an increasing interest in maternal effects, ecological and evolutionary determinants of the transfer of maternal antibodies remain poorly studied. The analysis of a theoretical framework specially developed to include a transgenerational transfer of immunity show that the evolution of an ability to temporarily protect offspring depends on the characteristics of both the host and the parasite. In particular, increasing the life span of the host favors the evolution of acquired immune responses and increases the duration of the protection offered by these mechanisms. Accordingly, a transgenerational vaccination study in a long-lived seabird revealed a particularly long half-life of maternal antibodies. Social conditions also proved important in a mammal species as they can allow for the broadening of the repertoire covered by maternal antibodies. The transfer of maternal antibodies could also modify epidemiological dynamics and could bbe an interesting asset if vaccination was used as a conservation tool. Finally, this mechanism could be used to estimate the exposure of mother and thus infer the dispersal rate between different habitat patches

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Fedna, Jimmy. "Prévalence du parasite Angiostrongylus cantonensis en Haïti chez les rats et gastéropodes". Electronic Thesis or Diss., Bourgogne Franche-Comté, 2024. http://www.theses.fr/2024UBFCD017.

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Ma recherche examine la prévalence et la répartition du parasite Angiostrongylus cantonensis en Haïti, également connu sous le nom de ver pulmonaire du rat, et qui est la première cause de méningite à éosinophiles chez l’homme dans le monde. Ce parasite a un cycle de vie complexe impliquant à la fois des hôtes définitifs (rats) et des hôtes intermédiaires (escargots et les limaces). J’ai documenté l'écologie du parasite et sa persistance deux décennies après sa découverte initiale dans le pays. Trois objectifs ont été fixés : synthétiser les connaissances sur les dimensions spatiales et écologiques d’A. cantonensis, déterminer sa présence et sa répartition en Haïti parmi les populations de rats et de gastéropodes à l'aide d'analyses moléculaires et morphologiques, et identifier les similitudes génétiques entre les souches haïtiennes et celles provenant d’autres régions du monde. Nous avons ciblé deux contextes écologiques contrastés : la vallée de l'Artibonite (milieu rural) et la zone urbaine de Port-au-Prince. L'échantillonnage a eu lieu pendant la saison des pluies et à la fin de la saison des pluies en raison de l'influence potentielle de la saisonnalité hydrologique sur la prévalence du parasite.Une revue systématique utilisant la méthode PRISMA a synthétisé les connaissances existantes sur la niche écologique du parasite, en mettant l'accent sur les facteurs abiotiques et biotiques affectant sa dynamique. Soixante-dix rats ont été capturés :23 Rattus norvegicus et 47 Rattus rattus. Sous la loupe binoculaire, nous avons récupéré des vers adultes chez seulement cinq rats (7%, 5/70) mais la détection moléculaire a révélé une prévalence d'A. cantonensis dans les poumons de rat de 31,4 %, (22/70), le parasite étant détecté dans quatre des huit sites, dont Port-au-Prince. La prévalence du parasite n’était pas reliée de manière significative aux variables prédictives telles que l'âge, la saison, le sexe et l'espèce de rat. Un seul haplotype COX1, le génotype II-G, a été identifié en Haïti, ce qui suggère une large répartition similaire à celle d'autres régions. La technique qPCR AcanR3990 a permis d'identifier deux échantillons positifs d'espèces de gastéropodes : Subulina octona à Port-au-Prince et une limace de la famille des Veronicellidae dans l’Artibonite, concordant avec la présence du parasite retrouvé chez les rats à ces endroits.C'est la première étude sur A. cantonensis en Haïti portant à la fois sur les hôtes définitifs et intermédiaires. Les diagnostics moléculaires par PCR révèlent une prévalence plus élevée que l'identification morphologique, ce qui est prometteur pour l'étude systématique de la contamination potentielle des espèces hôtes. Les résultats indiquent une endémicité du parasite potentiellement principalement liée à deux espèces de gastéropodes : l'escargot terrestre S. octona et les limaces Veronicellidae, ainsi que les rats R. rattus et R. norvegicus, soulignant les risques importants pour la santé des populations locales
My research examines the prevalence and distribution of the parasite Angiostrongylus cantonensis, also known as the rat lungworm, in Haiti. It is the leading cause of eosinophilic meningitis in humans worldwide. This parasite has a complex life cycle involving definitive hosts (rats) and intermediate hosts (snails and slugs). I documented the parasite's ecology and persistence two decades after its initial discovery in the country. Three objectives were set: synthesizing knowledge on the spatial and ecological dimensions of A. cantonensis’ niche, determining its presence and distribution in Haiti among rat and gastropod populations using molecular and morphological analyses, and identifying genetic similarities between Haitian strains and those from other regions of the world. We targeted two contrasting ecological contexts: the Artibonite Valley (rural environment) and the urban area of Port-au-Prince. Sampling occurred during and at the end of the rainy season due to the potential influence of hydrological seasonality on parasite prevalence. A systematic review using the PRISMA method synthesized existing knowledge on the parasite's ecological niche, focusing on abiotic and biotic factors affecting its dynamics. Seventy rats were captured:23 Rattus norvegicus and 47 Rattus rattus. Under a binocular loupe, we recovered adult worms from only five rats (7%, 5/70), but molecular detection revealed a prevalence of A. cantonensis in rat lungs of 31.4% (22/70), with the parasite detected in four of the eight sites, including Port-au-Prince. Parasite prevalence was not significantly related to predictive variables such as age, season, sex, and rat species. Only one COX1 haplotype, genotype II-G, was identified in Haiti, suggesting a widespread distribution similar to other regions. The qPCR technique AcanR3990 identified two positive samples of gastropod species: Subulina octona in Port-au-Prince and a Veronicellidae slug in the Artibonite, indicating the presence of the parasite found in rats at these locations. This is the first study on A. cantonensis in Haiti addressing both definitive and intermediate hosts. Molecular diagnostics by PCR reveal a higher prevalence than morphological identification, promising for the systematic study of potential host species contamination. Results indicate that endemicity of the parasite may primarily be linked to two gastropod species: the land snail S. octona and Veronicellidae slugs, as well as R. rattus and R. norvegicus rats, highlighting significant health risks for local populations

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Jossart, Quentin. "Ecologie moléculaire d'une relation hôte-parasite en contexte insulaire marin: crabes parasites des oursins spatangues en Mer des Caraïbes". Doctoral thesis, Universite Libre de Bruxelles, 2014. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209237.

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Comparer les structures génétiques des populations d’un couple hôte-parasite permet d’évaluer les facteurs qui façonnent la dispersion ainsi que la potentialité d’adaptation locale de ces espèces. Le modèle étudié est le crabe ectoparasite Dissodactylus primitivus et son oursin-hôte Meoma ventricosa, endémiques des Caraïbes et des côtes américaines voisines.

En étudiant des populations le long de l’arc antillais et de la côte panaméenne, ce travail a mis en évidence que la structure génétique des populations du parasite D. primitivus diffère fortement de celle de son hôte M. ventricosa (microsatellites et cytochrome oxydase I). En effet, alors que les populations du parasite présentent une différenciation au sein de cette région, celles de l’hôte sont génétiquement homogènes. Ce contraste peut être expliqué par des caractères biologiques et écologiques (fécondité, habilité à la nage, disponibilité de l’habitat) et suggère des potentialités d’adaptation locale distinctes. La distance géographique semble être importante dans la structuration des populations du crabe mais la courantologie ou encore des évènements passés (glaciations) jouent également un rôle. A l’échelle d’une même île, les crabes ne présentent pas de différenciation entre des sites distincts. En outre, nous avons pu montrer que des crabes issus d’hôtes d’espèces différentes ne sont pas différenciés génétiquement ce qui pourrait être liée à la mobilité des crabes adultes. Par des analyses de paternité, nous avons souligné cette mobilité, démontrant que le mode de reproduction du crabe est de la polygamie mais aussi que des accouplements pouvaient avoir lieu entre crabes d’espèces hôtes distinctes.

Doctorat en Sciences
info:eu-repo/semantics/nonPublished

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GIUDICI, CLAUDIO JUAN. "Correspondances entre les variabilites morphologique et ecologique chez le nematode haemonchus placei, parasite de bovins". Tours, 1999. http://www.theses.fr/1999TOUR4027.

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Les nematodes trichostrongylides ont un cycle en deux phase, l'un parasitaire chez les ruminants, l'autre libre sur le paturage. Ils sont tres repandus de part le monde chez les ruminants domestiques. Leur pathogenicite a amene de nombreuses etudes a etre realisees, le plus souvent sur des problemes tres appliques (impact sur la sante, moyens de lutte etc. ). Des etudes de systematique, de genetique et d'ecologie manquent pour ces nematodes aux capacites evolutives importantes. Le cas d'haemonchus placei est particulierement bien representatif : son statut taxinomique a ete bouleverse plusieurs fois, le polymorphisme morphologique des femelles a ete decrit avec de lourdes incertitudes, et les aptitudes ecologiques de l'espece et de ses morphes, ont ete a peine evoquees. En fait, ce nematode tres frequent n'a jamais ete completement decrit, et c'est donc a cette premiere entreprise que nous nous sommes attache. Au cours de cette description nous avons remarque que trois entites se degageaient nettement, l'une presente en australie, et les deux autres en amerique du nord et du sud et en afrique de l'ouest. L'importance de ces differences nous a conduit a definir trois sous-especes h. Placei placei (australie), et h. Placei argentinensis (ameriques) et h. Placei africanus (afrique). Contrairement a ce que nous supposions, par les quelques travaux realises anterieurement et en raison de la similarite avec haemonchus contortus, seulement deux morphes femelles (linguiforme et boutonnes) sont presents, le morphe lisse etant absent. Les deux morphes sont retrouves en proportions tres differentes d'un site a l'autre : le morphe linguiforme passe ainsi de 10% en mauritanie a 96% en cote d'ivoire (h. P. Africanus) et de 14% au mexique a 76% au bresil (h. P. Argentinensis). Ces proportions sont stables sur un site. Nous avons emis l'hypothese que ces morphes etait controles genetiquement et qu'ils etaient egalement indicateurs d'aptitudes ecologiques bien definies. Nous avons selectionne les deux morphes, en nous fondant sur l'aspect des femelles, les males correspondants n'etant pas differenciables. En 4 a 5 generations de selections menees chez des agneaux, nous obtenons des lignees linguiformes ou boutonnees qui comportent plus de 90% du morphe selectionne. Le mecanisme genetique retenu est celui d'un locus a deux alleles, le morphe linguiforme dominant le morphe boutonne. Nous avons d'ailleurs eu l'occasion de verifier que la fitness (ou succes reproductif) des linguiformes etait superieure dans nos conditions de selection (primo-infestations, hotes non electifs mais immuno-deprimes, et phase libre realisee, en conditions optimales). Dans les conditions naturelles, la fitness dependra vraisemblablement du type d'hote (electif : bovin, ou non : ovin ou caprin) et de l'environnement climatique. Il ressort que le morphe linguiforme a une capacite d'infestation superieure des hotes electifs bovins et que le morphe boutonne par contre s'etablit bien chez les hotes non electifs. Les capacites a se developper au cours de la phase libre sont superieures pour le morphe bouton dans les regions seches et le morphe linguiforme dans les regions humides, ce qui est corrobore par les etudes d'ecologie experimentale. Les assemblages de morphotypes correspondent donc a des adaptation regionales qui pourraient etre appelees ecotypes. H. Placei s'est revele un nematode polymorphe aux aptitudes diversifiees, bien que notre etude n'ait porte que sur des isolats africains et americains et un isolat australien. Il serait interessant de l'etudier a une plus large echelle (australasie comprise) pour definir l'ensemble des sous-especes, de tenter d'expliquer leur apparition par les migrations des bovins hotes a travers les continents. Il serait egalement interessant d'apprecier le polymorphisme et sa fonction adaptative au sein de chaque sous-espece.

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Beltran, S. "Monogamie et changements de partenaires chez un parasite monogame, Schistosoma mansoni". Phd thesis, Université de Perpignan, 2009. http://tel.archives-ouvertes.fr/tel-00939328.

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La monogamie est un système d'appariement qui lie une seule femelle à un seul mâle. Cette monogamie peut être définie comme sociale et génétique (au-delà de l'observation du couple, la descendance est seulement issue de ce couple, aucun changement de partenaire n'apparaît), ou comme sociale et non génétique (dans ce cas, des infidélités ou des divorces peuvent être observés). Ce système d'appariement est très rare dans le monde animal. Il concerne moins de 1% des animaux et la majeure partie des études sur le monogamie a été réalisée sur des vertébrés (notamment sur les oiseaux dont 90% des espèces présentent ce système monogame). Plus rares sont les études réalisées sur les invertébrés (quelques cas de monogamie étudiée chez des crustacés, des insectes ...). Pourtant l'étude de la monogamie à un niveau taxonomique inférieur permet de comprendre ses caractéristiques en éliminant la complexité sociale (apprentissage, imitation ...) présente chez les vertébrés. Schistosoma mansoni est un parasite (responsable de la bilharziose) qui présente plusieurs aspects intéressants du point de vue système d'appariement : (1) la femelle vit dans le canal gynéchophore de son mâle, nous observons bien un couple formé d'une seule femelle et d'un seul mâle, il s'agit donc d'une monogamie sociale ; (2) S. mansoni est l'espèce monogame de rang taxonomique le plus bas à notre connaissance, ce qui permet d'éliminer au maximum les biais de complexité sociale cités précédemment ; (3) enfin, cette espèce parasite présente des avantages d'un point de vue expérimental : les sexes et génotypes des individus utilisés peuvent et sont contrôlés en laboratoire et des populations "naturellement" clonales sont à notre disposition. C'est pourquoi, nous nous sommes intéressés à la monogamie chez cet invertébré parasite monogame. Plusieurs questions sont développées durant cette thèse : qui est monogame parmi les Schistosomatidae et pourquoi ? Est-ce que une monogamie sociale et génétique ou sociale et non génétique (i.e. des changements de partenaires sont-ils observés) ? Quels sont les facteurs impliqués dans ces changements de partenaire (dissimilarité entre les partenaires du couple, biais de sex ratio en faveur des males, différences neutres, fonctionnelles et phénotypiques entre les mâles, effet du système immunitaire de l'hôte vertébré) ? C'est par l'association de réflexions et d'expérimentations que nous tentons de répondre à ces questions.

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De, Garine-Wichatitsky Michel de. "Ecologie des interactions hôtes/vecteurs : analyse du système tiques/ongulés sauvages et domestiques en zone tropicale". Montpellier 2, 1999. http://www.theses.fr/1999MON20114.

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Les hotes peuvent-ils eviter les parasites ? dans une perspective ecologique et evolutive, nous avons etudie l'infestation des ongules par des tiques, ainsi que la distribution spatio-temporelle de ces vecteurs et de leurs hotes. Un modele theorique est presente qui relie (1) les niveaux d'infestation des ongules ; a (2) l'utilisation de l'habitat par les ongules ; et (3) l'abondance des tiques dans la vegetation. Les parametres du modele ont ete mesures sur un ranch mixte faune/betail du zimbabwe en fonction des saisons : (1) les niveaux d'infestation sont variables entre les especes d'ongules ; (2) l'utilisation de l'habitat par les ongules differe entre les especes, mais ne semble pas expliquer les variations d'infestation entre especes ou entre individus-hotes ; (3) l'abondance des larves de tiques dans la vegetation revele deux distributions garantissant le contact avec les ongules : une distribution imprevisible dans le temps et l'espace, et donc inevitable ; une distribution previsible, mais inevitable car associee a des ressources indispensables aux hotes (points d'eau et ressources fourrageres). Les strategies eventuelles d'evitement des tiques par les ongules sont abordees en fonction des compromis qu'elles impliquent pour les hotes, de la previsibilite du risque parasitaire, et de l'agregation des parasites a differentes echelles. Les tiques et les maladies a tiques constituent un frein majeur au developpement de l'elevage en zone tropicale. De plus, face a la multiplication des conflits entre la faune et les activites pastorales en afrique (competition pour les paturages et transmission de maladies), les systemes mixtes faune/betail permettent de concilier des objectifs de conservation et de productions animales. Nos resultats sont discutes en relation avec la spatialisation du risque vectoriel, les methodes de lutte contre les tiques, et l'interet d'une etude genetique des vecteurs pour etablir le role de reservoir eventuel de la faune sauvage.

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Sire, Christel. "Ecologie moléculaire des populations de Schistosama mansori parasite du rongeur Rattus rattus et du mollusque Biompharalaria glabrata en Guadeloupe : échelles spatiales et fonctionnelles". Perpignan, 2000. http://www.theses.fr/2000PERP0384.

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Le fonctionnement dynamique et génétique d'un sysème parasite/hôtes/environnement est étudié en relation avec les différentes échelles spatiales (régionale vs locales) et fonctionnelles (populations de parasites adultes chez les hôtes défénitifs vs populations de parasites larvaires chez les hôtes intermédiaires)
In this study, we investigated the genetic and dynamc organisation of a parasite/hosts/environment system, at two different spatial scales (regional vs local), and at two different functional scales (adult parasite populations within intermediate hosts)

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Lion, Sébastien. "Structuration spatiale et évolution des populations". Paris 6, 2007. http://www.theses.fr/2007PA066354.

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Depuis une vingtaine d'années, le rôle de l'auto-structuration spatiale dans les processus évolutifs est devenu un point d'intérêt majeur en écologie évolutive. Parallèlement, le domaine de l'écologie spatiale a connu une véritable révolution avec l'introduction de nouvelles techniques de modélisation prenant en compte explicitement à la fois la structure spatiale et l'individualité. Le but de cette thèse est de comprendre comment l'interaction entre la dynamique écologique spatiale et l'évolution, grâce à une approche théorique qui combine simulations et modèles analytiques. Cette thèse a trois axes principaux. Dans une première partie, nous passons en revue les progrès théoriques que les modèles spatialisés les plus récents ont apportés à notre compréhension de l'évolution, et nous soulignons que la plupart des résultats se comprend mieux dans le cadre théorique plus large de la sélection multi-niveaux et de la sélection de parentèle. Dans un deuxième temps, nous développons un modèle pour l'évolution de populations structurées dans l'espace et en classes. Nous proposons une technique pour calculer la condition d'invasion d'un mutant rare au moyen d'équations de corrélations (ou approximation des paires), et l'appliquons à un modèle d'interactions entre adultes et jeunes. Ce modèle est adapté à l'étude de l'évolution des soins parentaux et du cannibalisme des jeunes, et nous permet de généraliser les conclusions d'études précédentes sur l'évolution de la coopération dans des populations visqueuses. En utilisant une méthodologie qui ne repose pas sur des approximations de la structure spatiale, nous donnons un éclairage sur les pressions de sélection qui s'appliquent sur les soins parentaux et le cannibalisme, et nous montrons qu'une variante de la règle de Hamilton émerge de la dynamique écologique spatiale. Nous montrons aussi que la forme des compromis évolutifs entre les traits démographiques est un facteur crucial qui détermine l'issue de l'évolution dans le modèle spatialisé, et que le rôle des corrélations spatiales d'ordre supérieur à trois peut avoir une importance quantitative subtile, mai
Over the last two decades, the role of spatial self-structuring as a template for evolution has been a focus of increasing attention. At the same time, the field of spatial ecology has seen radical new developments with the advent of new modelling techniques that explicitely take into account both spatial structure and individuality. The aim of this thesis is to try an understand the interplay between spatial ecological dynamics and evolution, through a theoretical approach that uses both simulations and analytical models. The thesis unfolds along three axes. In a first part, we review the theoretical progress that the latest-spatially explicit models have brought to our understanding of evolution, and argue that most results are best understood in the larger framework of multilevel and kin selection. Secondly, we develop an analytical model for the evolution of populations that are structured both in space and in discrete classes. A technique to derive the invasion condition of a rare mutant is proposed using correlation equations (aka pair approximation), and applied to a model of juvenile-adult interactions. This model is adapted to the study of the evolution of parental care and juvenile cannibalism, and allows us to extend previous studies of the evolution of cooperation in viscous populations to altruistic interactions between different classes of individuals. Using a methodology that does not resort to approximations of the spatial structure, we shed light on the selective pressures on parental care and cannibalism, and show we can recover Hamilton's rule and relatedness as emergent properties of the spatial ecological dynamics. We also show that the shape of trade-off curves is crucial in determining the evolutionary outcome in the spatial model, and that in age-structured populations, the evolutionary role of higher-order spatial moments can be very subtle, but quantitatively important. Finally, we study the evolution of dispersal in host-parasite interactions. Evolution of the manipulation of host dispersal behaviour by parasites is shown to depend both on the scale of dispersal and on th

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GERARD, CLAUDIA. "Ecologie d'une interaction durable : schistosoma mansoni/biomphalaria glabrata. dynamique de l'infrapopulation parasite dans l'ecosysteme mollusque, interactions spatiales et energetiques". Paris 6, 1993. http://www.theses.fr/1993PA066373.

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Le systeme s. Mansoni/b. Glabrata est utilise comme modele pour une approche ecologique des interactions ecosysteme hote-infrapopulation parasite. La dynamique des infrapopulations parasites est etudiee pour differentes tailles (age) d'ecosysteme mollusque et pour des nombres varies d'individus fondateurs de l'infrapopulation parasite, en relation avec les contraintes spatiales et energetiques du systeme. Contrainte spatiale. La taille de l'infrapopulation parasite evolue en fonction de l'augmentation de la taille de son biotope (glandes digestive et genitale); des mecanismes de regulation interviennent pour limiter et stabiliser la croissance de l'infrapopulation parasite a sa valeur d'equilibre par rapport a la capacite biotique de l'hote. Les consequences fonctionnelles du mode d'integration spatiale par remplacement du parasite sont analysees au niveau de l'acquisition des ressources de l'hote. Contrainte energetique. Les modifications des traits de vie de l'hote (survie, croissance, fecondite) qui resultent de la contrainte energetique du parasite sur l'hote, sont interpretees en termes de competition par exploitation ou par interference. L'existence d'une manipulation de la physiologie de l'hote par le parasite est demontree: stimulations precoces de la croissance ou de la fecondite selon l'age du mollusque. La valeur adaptative de ces modifications est discutee par rapport a la performance du systeme trematode/mollusque

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Roy, Lise. "Ecologie évolutive d'un genre d'acarien hématophage : approche phylogénétique des délimitations interspécifiques et caractérisation comparative des populations de cinq espèces du genre Dermanyssus (Acari : Mesostigmata)". Phd thesis, AgroParisTech, 2009. http://pastel.archives-ouvertes.fr/pastel-00005531.

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Les acariens microprédateurs du genre Dermanyssus (espèces du groupe gallinae), inféodés aux oiseaux, représentent un modèle pour l'étude d'association lâche particulièrement intéressant : ces arthropodes aptères font partie intégrante du microécosystème du nid (repas de sang aussi rapide que celui du moustique) et leurs hôtes sont ailés. En outre, D. gallinae est une espèce d'importance économique, ce qui rend possible des comparaisons entre colonisation de milieux anthropisés et sauvages. Au début de l'étude, les espèces du groupe gallinae sont très mal délimitées. Les caractères morphologiques utilisés sont variables au sein de l'espèces, voire de la population, très chevauchants entre espèces. Afin de mieux comprendre les exigences écologiques du développement de D. gallinae et d'appréhender ses voies de dissémination, une investigation comparative basée sur des séquences d'ADN entre espèces du groupe gallinae a été adoptée. Un cheminement d'ordre taxinomique a permis de poser les bases nécessaires. Ensuite, l'exploration de certaines caractéristiques écologiques du groupe gallinae en relation avec sa phylogénie (spécificité d'hôte, flexibilité évolutive) a été menée à bien. Une espèce a été décrite, D. apodis, une lignée de D. gallinae constitue aussi une probable espèce inédite et D. longipes regroupe deux entités. Des différences écologiques marquées entre D. gallinae et les autres espèces semblent résulter non seulement de l'activité humaine, mais aussi de caractéristiques intrinsèques. Aujourd'hui, le rôle des flux commerciaux dans la dispersion de D. gallinae en élevage de pondeuses s'avère primordial, au moins en France, celui des oiseaux sauvages presque nul.

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Libri sul tema "Ecologie parasite"

Poulin, Robert. Evolutionary ecology of parasites. 2^a ed. Princeton, N.J: Princeton University Press, 2007.

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Poulin, Robert. Evolutionary ecology of parasites: From individuals to communities. London: Chapman & Hall, 1998.

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D, Rollinson, Anderson Roy M e Linnean Society of London, a cura di. Ecology and genetics of host-parasite interactions: Papers presented at an International Symposium organized by the Linnean Society of London and the British Society for Parasitology, held at Keele University, 12-13 July 1984. London: Published for the Linnean Society of London [by] Academic, 1985.

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D, Rollinson, Anderson Roy M, Linnean Society of London e British Society for Parasitology, a cura di. Ecology and genetics of host-parasite interactions: Papers presented at an international symposium organized by the Linnean Society of London and the British Society for Parasitology, held at Keele University, 12-13 July 1984. London: Orlando, Fla., 1985.

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Telford, Sam Rountree. The ecology of a symbiotic community. Malabar, Fla: Krieger Pub. Co., 1997.

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Davydov, O. N. Parazito-khozi͡a︡innye otnoshenii͡a︡ pri t͡s︡estodozakh ryb. Kiev: Nauk. dumka, 1991.

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W, Esch Gerald, Bush Albert O. 1948- e Aho John M, a cura di. Parasite communities: Patterns and processes. London: Chapman and Hall, 1990.

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I, Rothstein Stephen, e Robinson Scott Kuehner, a cura di. Parasitic birds and their hosts: Studies in coevolution. New York: Oxford University Press, 1998.

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T, Grenfell B., e Chappell Leslie H, a cura di. Ecology of wildlife: Host-parasite interactions. Cambridge: Cambridge University Press, 1995.

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A, Huffman Michael, e Chapman Colin A, a cura di. Primate parasite ecology: The dynamics and study of host--parasite relationships. Cambridge: Cambridge University Press, 2009.

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Capitoli di libri sul tema "Ecologie parasite"

Hechinger, Ryan F., Kevin D. Lafferty e Armand M. Kuris. "Parasites". In Metabolic Ecology, 234–47. Chichester, UK: John Wiley & Sons, Ltd, 2012. http://dx.doi.org/10.1002/9781119968535.ch19.

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Bandyopadhyay, P. K., N. R. Das e Amit Chattopadhyay. "Ecology of Parasites". In Biochemical, Immunological and Epidemiological Analysis of Parasitic Diseases, 305–8. Singapore: Springer Singapore, 2022. http://dx.doi.org/10.1007/978-981-16-4384-2_10.

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Lambers, Hans, F. Stuart Chapin e Thijs L. Pons. "Parasitic Associations". In Plant Physiological Ecology, 491–503. New York, NY: Springer New York, 2008. http://dx.doi.org/10.1007/978-0-387-78341-3_15.

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Bataille, Arnaud, Iris I. Levin e Eloisa H. R. Sari. "Colonization of Parasites and Vectors". In Disease Ecology, 45–79. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-65909-1_3.

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Santiago-Alarcon, Diego, e Jane Merkel. "New Host-Parasite Relationships by Host-Switching". In Disease Ecology, 157–77. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-65909-1_7.

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Gómez-Gutiérrez, Jaime, e José Raúl Morales-Ávila. "Parasites and Diseases". In Biology and Ecology of Antarctic Krill, 351–86. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-29279-3_10.

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Rizwan, Hafiz Muhammad, Saima Naz, Mohsin Raza, Asif Iqbal, Tahira Iftakhar, Haider Abbas e Tayyaba Akhtar. "Biology and Ecology of Parasites". In Parasitism and Parasitic Control in Animals, 1–20. GB: CABI, 2023. http://dx.doi.org/10.1079/9781800621893.0001.

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Levin, Iris I., e Arnaud Bataille. "Movement Among Islands by Host, Vector, or Parasite". In Disease Ecology, 181–212. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-65909-1_8.

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Thieltges, David W., Kim N. Mouritsen e Robert Poulin. "Ecology of Parasites in Mudflat Ecosystems". In Mudflat Ecology, 213–42. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-99194-8_9.

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Varley, M. J., M. J. W. Copland, S. D. Wratten e M. H. Bowie. "Parasites and Predators". In Video Techniques in Animal Ecology and Behaviour, 33–63. Dordrecht: Springer Netherlands, 1994. http://dx.doi.org/10.1007/978-94-011-0699-3_3.

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Atti di convegni sul tema "Ecologie parasite"

Sivkova, T. N., e P. A. Kosintsev. "FINDING OF ASCARID EGGS IN MAMMOTH". In THEORY AND PRACTICE OF PARASITIC DISEASE CONTROL. All-Russian Scientific Research Institute for Fundamental and Applied Parasitology of Animals and Plant – a branch of the Federal State Budget Scientific Institution “Federal Scientific Centre VIEV”, 2023. http://dx.doi.org/10.31016/978-5-6048555-6-0.2023.24.426-430.

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Mammoth parasites (Mammuthus primigenius Blumenbach, 1799) are currently being studied according to the morphological characteristics of parasite residues due to the lack of established genetic markers for performing genetic tests. A parasitological study of the intestinal contents of two mammoths was carried out – Mongochensky (Gydan Peninsula) and Tadibе (Yamal Peninsula). We conducted a parasitological study of the remains of the intestines of two mammoths - Mongochensky and Tadibe, provided by employees of the Institute of Plant and Animal Ecology of the Ural Branch of the Russian Academy of Sciences. The work was carried out according to the generally accepted in paleoparasitology method with the use of residue rehydration and the subsequent use of the combined and sedimentation method. In a parasitological study of the intestinal contents of the Mongochensky mammoth, no parasites were found, while analysis of the material from the mammoth from Tadibe revealed two nematode eggs. The number of eggs found was small 1.5 eggs per 1 g of feces. Large sizes, rounded shape, the presence of a thick layered shell made it possible to identify these objects as eggs of representatives of the family Ascarididae Baird, 1853. The structure of the eggs was similar to ones from modern horse parascarids. The diameter of the eggs was 78.68±1.19 and 87.94±0.47 mkm, the wall thickness was 4.14±0.29 and 4.48±0.34 microns, which is comparable to similar indicators of modern representatives. This is the first report of the detection of Ascarididae nematode in mammoths.

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Lisovsky, P. A., e N. S. Malysheva. "THE ECOLOGY OF TICKS OF THE FAMILY IXODIDAE IN THE KURSK REGION". In THEORY AND PRACTICE OF PARASITIC DISEASE CONTROL. VNIIP – FSC VIEV, 2024. http://dx.doi.org/10.31016/978-5-6050437-8-2.2024.25.241-245.

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Ixodid ticks are temporary obligate bloodsuckers attacking at all development stages. They pose danger to humans and animals as they are carriers of various natural focal infections. The current climate change trend towards warming creates more favorable conditions for the spread and vital activity of many arthropods including ixodid ticks. This article discusses ecological features of family Ixodidae ticks in the Kursk Region. A comparative analysis of the species ratio and biotopic allocation as well as number dynamics of ixodid ticks was carried out. In the Kursk Region in 2022–2023, 2 species of ixodid ticks were recorded, namely, Dermacentor reticulatus (Fabricius, 1794) and Ixodes ricinus (Linnaeus, 1758). The most numerous species was D. reticulatus. The activity peak periods of the species inhabiting the Region differ. According to our observations, the first D. reticulatus activity peak begins in March followed by a decrease in summer months with the second activity peak in September. The I. ricinus activity begins in March-April depending on weather conditions and lasts until the end of October.

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Didakis, Stavros. "Computationally-Enhanced Ecologies, Organisms, and Parasites. Speculative Explorations of Symbiotic Oscillations". In MAB18: Media Architecture Biennale. New York, NY, USA: ACM, 2018. http://dx.doi.org/10.1145/3284389.3284496.

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Jaenike, John. "Symbiont-mediated shift in the evolutionary ecology of host-parasite interactions". In 2016 International Congress of Entomology. Entomological Society of America, 2016. http://dx.doi.org/10.1603/ice.2016.92973.

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Moskvin, A. S. "DEVELOPMENTAL BIOLOGY FORMULA: NEW STYLIZED CATEGORY TO REPRESENT THE MAIN PARAMETERS OF HELMINTH BIOLOGY AND ECOLOGY". In THEORY AND PRACTICE OF PARASITIC DISEASE CONTROL. All-Russian Scientific Research Institute for Fundamental and Applied Parasitology of Animals and Plant – a branch of the Federal State Budget Scientific Institution “Federal Scientific Centre VIEV”, 2023. http://dx.doi.org/10.31016/978-5-6048555-6-0.2023.24.312-318.

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Within the section of general helminthology, based on the diversity analysis of biological cycles of helminth development, and the objective availability of common algorithms in closely related species, a conceptual proposal has been developed to introduce a new stylized category, the Helminth Developmental Biology Formula (DBF), into theory and scientific practice. The new category, the DBF, is designed for a logically sound, stylized and concise presentation of essential elements of bioecological characteristics of helminths. Basic regulations for the formation of the formula structure have been developed. A number of indicative parameters are proposed which, in accordance with helminthological terminology and pictograms, form the informational basis of the helminth DBF category. The regulation algorithm is universal, and, taking into account the bioecology characteristics of helminths, it is applicable to the DBF formation for representatives from various zoological taxa. On the example of biological cycles of development of trematode Paramphistomum daubneyi Dinnik, 1962, cestode Spirometra erinacei-europaei (Rudolphi, 1819), nematode Avioserpens mosgovoyi Suprjaga, 1965, Acanthocephala Macracanthorhynchus hirudinaceus (Pallas, 1781), and Monogenea Diplozoon paradoxum Nordman, 1832, in a stylized format, the structure and information content of the category Helminth Developmental Biology Formula are presented. The field of practical use of the helminth DBF is the following: 1) scientific and methodological, educational and reference helminthological literature, as an additional subheading within the main Helminth Developmental Biology Section; 2) in computer databases of various thematic orientation, in scientific characterization of the main bioecological parameters of helminths, due to the need to present material in a concise format.

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Kachri, Zeta (Georgia), e Sean Hanna. "Parasitic Ecologies - Algorithmic Space through Diffusion-Limited Aggregation of Truncated Octahedrons". In eCAADe 2014: Fusion. eCAADe, 2014. http://dx.doi.org/10.52842/conf.ecaade.2014.2.539.

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Rusu, Ștefan, Dumitru Erhan, Oleg Chihai, Maria Zamornea, Ion Gologan, Nina Chihai, Mihail Pruteanu e Vadim Rusu. "Diversitatea helmintofaunei la câinii maidanezi în dependență de vârstă și biotop". In International symposium ”Functional ecology of animals” dedicated to the 70th anniversary from the birth of academician Ion Toderas. Institute of Zoology, Republic of Moldova, 2019. http://dx.doi.org/10.53937/9789975315975.58.

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More than 1200 biological samplings were collected from the free-ranging dogs of various ages and biotopes that allowed to study the diversity of their helminth fauna. The results of investigations revealed that 95% of researched dogs are infested with multiple parasites mostly endoparasites (Eimeria canis, Dipilidium caninum, Echinococcus granulosus, Toxocara canis, Toxascaris leonina, Ancylostoma caninum and Trichocephalus vulpis.). It was established that the level of contamination with the all above mentioned parasites in free-ranging dogs is hogher in the adult dogs compared to the young ones. The young dogs were predominantly infested with parasites from the class Sporozoite (Eimeria canis) and the Nematoda class (Toxocara leonina). The level of contamination with parasites of the free-rangeging dogs is higher in the rural regions compared to the urban area.

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Kambarov, S. S., e H. S. Eshova. "PHYTONEMATODES IN CABBAGE (BRASSICA OLERACEA SUBSP. CAPITATA L.) AGROCENOSES IN EASTERN FERGANA". In THEORY AND PRACTICE OF PARASITIC DISEASE CONTROL. VNIIP – FSC VIEV, 2024. http://dx.doi.org/10.31016/978-5-6050437-8-2.2024.25.153-157.

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The article provides data on the species composition, ecological groups, and distribution of plant nematodes in cabbage agrocenoses in Eastern Fergana. The result identified 39 plant nematode species that belonged to two subclasses, 7 orders, 15 families and 25 genera. In terms of species composition, representatives of the orders Rhabditida, Dorylaimida and Tylenchida dominated. Aphelenchida species had an average abundance; species of Plectida, Mononchida and Enoplida orders had the lowest abundance. Most of the identified species were distributed in the root system and rhizosphere. The above-ground organs and the root system of the cabbage mainly contained species of the genera Rhabditis, Panagrolaimus, Chiloplacus, Aphelenchus, and Ditylenchus. In terms of nutrition and ecology, pararhizobionts and devisaprobionts predominated; eusaprobionts, nonspecific and true phytohelminths were less common. Of true parasites, the most common species were Ditylenchus dipsaci, Meloidogyne hapla, and M. incognita. Of which, species of the genus Meloidogyne were more often found in the Jalaquduq and Asakinsky Districts, and the infection of cabbage roots by these nematodes was observed. Plant nematodes in cabbage agrocenoses were uneven in species and quantity. By region, number of species and their composition, the most common parasites were found in agrocenoses of the low adyr zone.

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Lisovsky, P. A., e N. S. Malysheva. "DISTRIBUTION OF IXODES RICINUS AS A VECTOR OF TICK-BORNE BORRELIOSIS PATHOGENS IN THE KURSK REGION". In THEORY AND PRACTICE OF PARASITIC DISEASE CONTROL. All-Russian Scientific Research Institute for Fundamental and Applied Parasitology of Animals and Plant – a branch of the Federal State Budget Scientific Institution “Federal Scientific Centre VIEV”, 2023. http://dx.doi.org/10.31016/978-5-6048555-6-0.2023.24.256-261.

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The article discusses some characteristics of the ecology of the tick Ixodes ricinus, which is often found in the central part of Eastern Europe and in many regions of the Russian Federation including the Kursk Region. Some circulation patterns of tick-borne borreliosis in natural foci of the Kursk Region and cases of infected humans are shown. The main material was the data from the state reports of the Federal Service for Supervision of Consumer Rights Protection and Human WellBeing for 2015–2021. A comparative analysis was conducted of the number of cases infected with ixodid tick-borne borreliosis (ITBB) with the I. ricinus infection rate in natural foci in the Kursk Region from 2015 to 2021. The ITBB circulation is widespread throughout the Kursk Region. According to our observations, the peaks of infection of humans with ITBB may depend on the circulation characteristics of Borrelia among I. ricinus and their feeders. In the results of the study, it can be noted that the I. ricinus population has a temporary downward trend, while the percentage of infected ticks fluctuates slightly and has a cyclic nature. The number of cases of people presenting tick bites is interrelated with the population density and the nature of ixodid ticks spreading in the Kursk Region.

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Chihai, Oleg, Dumitru Erhan, Stefan Rusu, Nina Talambuta, Victoria Nistreanu, Alina Larion, Maria Zamornea e Galina Melnic. "Structura parazitismului la șoarecele scurmător in ecosisteme forestiere". In International symposium ”Functional ecology of animals” dedicated to the 70th anniversary from the birth of academician Ion Toderas. Institute of Zoology, Republic of Moldova, 2019. http://dx.doi.org/10.53937/9789975315975.35.

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Bank vole (Myodes glareolus) is widely spread silvicolous species, inhabiting in woods, forest clearings, shrub vegetation, at forest edge, near ponds with abundant vegebtation. The parasite fauna is structured of 3 classes, 13 families, 14 genera and 15 species, of which 6.6% belong to class Trematoda, 46.7% to class Cestoda and 46.7% to class Nematoda. The results of the parasitological investigations show a prevalence of Plaghiorchis elegans of 13.8% and an average intensity of 3.8 ex, respectively with Mesocestoides lineatus larvae 14.0%, 1.5 ex, Paranoplocephala omphaloides - 10.3%, 2.7 ex, Rodentolipis straminea - 69.0%, 3.0 ex, Hydatigera taeniaeformis larvae - 10.3%, 1.0 ex, Catenotaenia cricetorum - 10.3%, 2.7 ex, Skrewabinotaenia lobata - 3 ex, Taenia pisiformis - 13.7%, 1.0 ex, Capillaria hepatica - 27.5% and liver infestation is about 50.0% (++), Syphacia stroma - 17.2%, 94 ex, Syphacia obvelata - 24,1%, 84,9 ex, Heligmosomoides polygirus - 10,0%, 5,3 ex, Strongyloides ratti - 6,9%, 23,3 ex, Mastophorus muris - 17,2%, 3 , 6 ex and Trichocephalus muris 17.2%, intensity 3.8 ex. The share of the Trematoda species is 6.6%, in the Cestoda class - 46.7%, and in the Nematoda class - 46.7%. The massive abundance of foxes on large land surfaces, including ecological plasticity with tendency toward synantropization, are the primary factors in the formation, maintenance and spreading of parasitosis outbreaks in natural and anthropic ecosystems. The aim of the research is to study the diversity of parasite fauna in Myodes glareolus from forest ecosystems with specifying the parasite taxonomic structure and determining the degree of infestation.

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Rapporti di organizzazioni sul tema "Ecologie parasite"

Leslie, Katie L., Rachel L. Welicky, Maureen A. Williams e Chelsea L. Wood. Parasite Biodiversity. American Museum of Natural History, 2020. http://dx.doi.org/10.5531/cbc.ncep.0150.

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In this module, students have the opportunity to discover the hidden world of parasites: they will come face to face with living parasites, learn about what differentiates parasites from free-living species, observe some common adaptations to a parasitic lifestyle, explore the ecological role of parasites in food webs, and assess how parasite abundance might change in a changing world. To accomplish these goals, this module includes an introductory PowerPoint presentation (including a video of parasite ecologist Dr. Chelsea L. Wood delivering this introductory lecture) and two exercises. The first exercise is a wet lab that involves dissecting an easy (and disturbing) source of live parasite material: fresh fish from your local seafood market. The second exercise is a computer lab that will allow students to engage with real data to answer the question: how do human impacts on ecosystems change the abundance of parasites in wildlife? This module will introduce students to the basics of parasite ecology and provide an opportunity to practice their data analysis and interpretation skills.

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