Search results for "Parasitism"

Estudio epidemiológico de las parasitosis intestinales en población infantil del departamento de Managua (Nicaragua)

2012

La presente tesis doctoral se enmarca en un macroproyecto que tiene por objeto conocer el estado coproparasitologico, y su correlación con diferentes factores intrínsecos y estrínsecos, de la población infantil nicaragüense. En esta primera contribución se estudia un total de 1936 sujetos (914 niños y 1022 niñas) de edades comprendidas entre 0 y 15 años del Departamento de Managua (Nicaragua), procedentes de diferentes escuelas y barrios, diferenciando la población objeto de estudio según su procedencia (zonas urbanas centro y periférica y zona rural). El estudio coproparasitológico sobre una muestra fecal por sujeto ha permitido detectar un espectro parasitario constituido por 20 especies …

Индивидуальность поведения рыб влияет на риск заражения паразитами [Personality influences risk of parasitism in fish]

2019

Influence of fish personality on infection rate is almost not studied. In the experiments on the young-of-the-year Oncorhynchus mykiss and cercariae of a trematode Diplostomum pseudospathaceum we tested the hypothesis that infection rate differs between more and less active (“bold” and “shy”) fish. Will individual differences in infection persist upon re-infection? Fish serve as a second intermediate host for this trematode. A positive correlation was found between the results of consecutive infections. Accumulation of parasites with successive infections leads to an aggregated distribution of D. pseudospathaceum among the hosts, affecting individual fitness and polymorphism in fish populat…

The endangered freshwater pearl mussel Margaritifera margaritifera shows adaptation to a local salmonid host in Finland

2022

1. The freshwater pearl mussel Margaritifera margaritifera (FPM) is an endangered unionid which has a glochidium larva that attaches to the gills of Atlantic salmon Salmo salar or brown trout S. trutta, although some FPM populations have been shown to exclusively attach to only one of these species. The origin of host fish populations may be crucial for conservation actions for this mussel species, but the relative suitability of local (sympatric) and non- local (allopatric) salmonid populations as the hosts for FPM has been studied only rarely. We hypothesised that FPM glochidia would show adaptation to local salmonid strains and, there-fore, that they would be more successful (abundant, l…

Divergent parasite infections in sympatric cichlid species in Lake Victoria

2018

Parasitism has been proposed as a factor in host speciation, as an agent affecting coexistence of host species in species‐rich communities and as a driver of post‐speciation diversification. Young adaptive radiations of closely related host species of varying ecological and genomic differentiation provide interesting opportunities to explore interactions between patterns of parasitism, divergence and coexistence of sympatric host species. Here, we explored patterns in ectoparasitism in a community of 16 fully sympatric cichlid species at Makobe Island in Lake Victoria, a model system of vertebrate adaptive radiation. We asked whether host niche, host abundance or host genetic differentiatio…

Host Developmental Stage Effects on Parasite Resistance and Tolerance.

2022

Hosts can defend themselves against parasites either by preventing or limiting infections (resistance) or by limiting parasite-induced damage (tolerance). However, it remains underexplored how these defense types vary over host development with shifting patterns of resource allocation priorities. Here, we studied the role played by developmental stage in resistance and tolerance in Atlantic salmon (Salmo salar). This anadromous fish has distinct life stages related to living in freshwater and seawater. We experimentally exposed 1-year-old salmon, either at the freshwater stage or at the stage transitioning to the marine phase, to the trematode Diplostomum pseudospathaceum. Using 56 pedigree…

Interactions between two parasites of brown trout (Salmo trutta): Consequences of preinfection

2018

Preinfection by one parasitic species may facilitate or by contrast hamper the subsequent penetration and/or establishment of other parasites in a host. The biology of interacting species, timing of preinfection, and dosage of subsequent parasite exposure are likely important variables in this multiparasite dynamic infection process. The increased vulnerability to subsequent infection can be an important and often overlooked factor influencing parasite virulence. We investigated how the preinfection by freshwater pearl mussel Margaritifera margaritifera glochidia could influence the success of subsequent infection by the common trematode Diplostomum pseudospathaceum in brown trout Salmo tru…

Evolutionary ecology of complex life cycle parasites : from genotypes to species assemblages

2012

Virulence evolution and immune defence : pathogen-host interactions between an environmentally transmitted bacterium Serratia marcescens and its inse…

2015

Analysis of Prey Composition in Eurasian Reed Warblers' Acrocephalus scirpaceus Droppings at Four Breeding Sites in Italy

2022

Our aim was to investigate the among-populations diversity of prey composition in Eurasian Reed Warblers’ diets via their droppings, both to assess the ecological validity of this sampling method and to test whether the prey species most abundant in fecal samples were also the most present in the Italian study site. We collected fecal samples at four sites throughout Italy, for a total of 144 samples. Within reedbeds, the breeding habitat of the Eurasian Reed Warbler, we also collected arthropods by carrying out entomological sweepings at one of the study sites. Within the fecal samples, we identified dozens of prey species, belonging mainly to Araneae, Coleoptera, Diptera, Hymenoptera and …

Glochidia Infection of Endemic Fishes from Lake Prespa, N. Macedonia

2022

Large freshwater mussels (Unionida) are long-lived, have large bodies, and produce thousands to millions of larvae (glochidia) that usually must attach to host fish tissue to complete their life cycle. This is an obligate parasitic stage of mussel larvae. However, less than one in onemillion find a suitable host and survive. The degree of host specificity varies among unionid species, from specialists that can successfully parasitize only one or a few closely related fish species to generalists that can complete development on a taxonomically broad range of fish species. In addition, freshwater mussels are among the most threatened groups of animals. This is due to habitat destruction, the …