R Poulin

..We suggest using this measure as a surrogate of web maturity or saturation as phylogenetic constraints can drive webs toward intervality...

..This previously unrecognized pattern of vector use is of importance for the persistence and transmission of the disease...

..This conclusion supports the view that the biological features of parasite species can potentially override local environmental conditions in driving parasite population dynamics...

..Each of the main collecting canals had 10-11 pairs of bilateral diverticula between the anterior edge of the ventral sucker and anterior body end. A brief discussion of its possible life cycle and ecology is also provided...

..This has important but previously overlooked implications for the interpretation of correlation coefficients, and the detection of competition in natural parasite communities...

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..In this system, the site of encystment within the fish host both promotes and constrains the adoption of a facultative, truncated life-cycle by the parasite...

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..Still, these results suggest that host specificity may have tended to decrease in many flea lineages, a process that could have been driven by the benefits of exploiting a wide range of host species...

..Due to the amphipods' ecological importance, their population decline may impact the coastal ecosystem as a whole...

..In this article, we focus on the spatial fragmentation of parasites and the population genetics processes behind their diversification in an effort to bridge the micro- and macro-scales...

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..Because the variables we investigated only explained about 10-11% of the variation in year of description among flea species, other factors must be important, such as temporal variability in the activity of flea taxonomists...

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..Abundance thus appears to be a true species trait in fleas, although it varies somewhat within bounds set by species-specific life history traits...

..This method should be extremely useful for experimental studies using trematode-host systems as models for addressing a range of ecological and evolutionary questions...

..The time has come to transform fish parasite ecology from a mostly descriptive discipline into a predictive science, capable of integrating complex ecological data to generate forecasts about the future state of host-parasite systems...

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..Interaction frequency may be a key determinant of specialisation and abundance in host-parasite systems...

..Understanding the links between anthropogenic changes and parasite evolution needs to become a cornerstone of public health planning, economic development and conservation biology...

..Here, the prospects offered by both approaches, as well as their limitations, are highlighted...

..The indices presented here capture essential features of resource use in parasite communities, and can be useful tools for comparative analyses...

..Possible alternative reasons for the pattern of positive association between the gymnophallid and the echinostomes are proposed...

..e. the parasite community level, appear highly contingent and far from universal. The general laws uncovered to date are proving valuable, as they offer glimpses of the underlying processes shaping parasite ecology and diversity...

..The presence of a large number of infected snails and tidal mixing of cercariae prior to infection results in crabs potentially harbouring hundreds of parasite genotypes despite the crabs' territorial behaviour...

..75, suggests that parasites are not like host tissues: they are able to appropriate more host resources than expected from metabolically derived host growth rates...

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..Our results demonstrate that the parasite species known at any given point in time are not a random subset of existing species, but rather a biased subset with respect to the parasites' biological properties...

..Topics include species identification, phylogeography, host specificity and speciation, population genetic structure, modes of reproduction and transmission patterns, and searching for loci under selection...

..If the number of parasite species exploiting a host population is not regulated by processes arising from within the parasite community, external factors such as host characteristics may be the main determinants of parasite diversity...

..Both these feeding behaviours of birds are known to occur in the field...

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..These relationships also suggest that adult size is to some extent determined by cystacanth size, and that the characteristics of the definitive host are not the sole determinants of parasite life history traits...

..We recommend the use of our new index in future comparative studies of host specificity, in particular when the focus is on the evolutionary history of parasites and of their past colonizations of host lineages...

..truncatus than the mass of any other species taken on its own. These results illustrate the importance of considering helminth interactions and helminth growth in a natural setting...

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..The results suggest that the anemone-cockle symbiosis is a non-obligate mutualistic relationship in which the former is provided with a suitable substrate for attachment whereas the latter obtains protection against parasitic infections...

..This is the first known marine host of a member of the family Mermithidae. Published records of mermithid nematodes from amphipods are presented...

..These results suggest that there is an increasing gap in the quantity and general importance of the research carried out on different helminth taxa...

..There may be some general, large-scale processes acting to structure helminth communities, but local or seasonal influences can often either mask their action, or play more important roles themselves...

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..The main consequence of this phenomenon is that worm sizes in the mermithid population are more homogeneous than they would be if intraspecific competition had stronger effects on worm growth...

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..The study of shorter life cycles offers an opportunity to understand the forces shaping the evolution of life cycles in general...

..Although the results are based on a limited number of parasite taxa, they suggest that parasites may be opportunistic in their colonization of new hosts, and not severely constrained by evolutionary baggage...

..We conclude that generalist parasites achieve higher abundance because of a combination of resource availability and stability...

..Finally, the definitive host, the gull, L. n. scopulinus, harbors the adult worms in its intestine...

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..Our results shed light on the conditions that may favour switching among intermediate hosts in digeneans, and on the presence/absence of host specificity in these parasites...

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..Finally, we present a method recently proposed for variation partitioning in a phylogenetic context, i.e. the phylogenetically structured environmental variation...

..The use of the index in comparative studies may help in determining whether interactive helminth communities are, as widely believed, more common in endothermic vertebrate hosts than in fish hosts...

..These findings are discussed with respect to the evolution of host specificity, its measurement, and historical differences between the two geographic areas considered...

..Apparently, crabs play a role as intermediate hosts of these nematode species. This is the first record of larval representatives of Cystidicolidae and Acuariidae from invertebrates in the Australasian Region...