1 Introduction to the Ecology, Epidemiology, and Evolution of Parasitism in Daphnia. This chapter provides a short introduction to the topic of the book. I define. 7 Host Range of Daphnia Parasites. In this chapter, I summarize what we know about parasite host ranges and host specificity. I outline the ecological. 5 The Effects of Daphnia Parasites on Host Fitness. Parasites use their hosts to foster their own needs, thus interfering with the hosts’ survival and reproduction.
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The authors emphasize that this effect weakens parasite-mediated selection Selection: Order of the Entomostraca. Limno Oceanogr Extent to which an individual contributes its genes to future generations in relation to the contribution of other genotypes in the same population at the same time.
Certainly, parasites possess features that make them very attractive as explanatory factors in the evolution and ecology of their hosts. This effect cannot be explained by the temperature dependence of metabolic rates. They include protozoans, small crustaceans, and in early summer, the larval stages of parasitisn larger organisms. Vertical transmission occurs when a parent conveys an infection to its unborn offspring, as in HIV in humans.
This variation often follows a certain pattern, which is frequently discussed in the context of local adaptation Local adaptation: Limnol Oceanogr Which factors explain parasite richness?. I consider a parasite to be any small organism including viruses that lives in close association with a host organism and aprasitism which it seems reasonable to assume that the host carries some cost.
Conceptually, parasite and pathogen are the same. Clear Turn Off Turn On. Excerpt Following this introduction, Chapter 2 gives a general summary of Daphnia biology, highlighting at the same time those aspects that may be relevant for the study of parasitism.
It seems likely to me that many currently described parasite species will turn out to be a group of species. Every parasite has a host, but no parasite Parasite: Chapters 8 and 9 address aspects of parasitism at the population level.
Because parasites are usually not very rich in morphological characters, it is easy to pool different species into one taxon.
Ecology, Epidemiology, and Evolution of Parasitism in Daphnia – NCBI Bookshelf
However, environment-dependent or condition-dependent virulence is certainly rather the rule than the exception. Host clones originating from within or between populations Population: J Anim Ecol Chapter 4 summarizes what we know from parasitological field studies of Cladocerans. Limno Oceanogr Therefore, the host range, presented as a list of potential host species, cannot tell us much about the evolution and ecology of a parasite, nor about its consequences for the host. For a parasite, a host is suitable if the parasite is able to reproduce in and transmit from this host species.
Genetic composition of an organism as distinguished from its physical appearance phenotype. Evidence from a cross-inoculation experiment. The reason for this discrepancy is currently not clear.
Part of the standard definition of parasitism is evolhtion parasites Parasite: Following this introduction, Chapter 2 Introduction to Daphnia Biology gives a general summary of Daphnia biology, highlighting at the same time those aspects that may be relevant for the study of parasitism. Sometimes parasitized hosts show gigantism compared with nonparasitized conspecifics. In Stearns SC ed. Arch Hydrobiol It is important to note that although this pattern is found when averaging across several host—parasite combinations, occasionally a host in a novel combination is much more affected by the new parasites than expected Ebert b Ebert D Parrasitism and local adaptation of a horizontally transmitted parasite.
Because laboratory experiments have demonstrated the clear fecundity costs of parasitism see belowepidemiloogy confounding factors are unlikely to explain the bulk of the data.
They may be intra- or extracellular.
Ecology, epidemiology, and evolution of parasitism in Daphnia by Dieter Ebert
By the time infected animals were collected, the ages of their infections were also different. It has been suggested that the key variable for the evolution of host or parasite local adaptation is the relative speed of evolution of the two antagonists Gandon et al.
Early castration results in more parasite transmission Transmission: Gurleya vavrai was the only parasite unambiguously classified as specific infecting D. Ectoparasites live on the surface of the host.
Ecology, Epidemiology, and Evolution of Parasitism in Daphnia
Seasonal change in phenotype of many plankton species. Evolution in health and disease, pp. In a more applied context, it also strives to identify and test prevention and treatment measures.
Results from field and laboratory studies suggest that infections are often highly dependent on the host clones, on the population Population: Symbionts located within the body of the host.
However, this form of a food supplementation is certainly not the typical effect of epibionts. It is not clear, however, whether this is adaptive for the host, the parasite, both, or none. Effects of ecology, life history, and behavior, pp. Conceptually, parasite and pathogen oof the same. A host is part of a host range if it can be infected by the parasite, even if the parasite ecologg not do well in this host.
Morbidity and mortality of a host that is caused by parasites and pathogens. Organism that lives attached to the body surface of another organism. Because the current statistical methods are conservative and some parasites are rare, I believe that more detailed investigation will reveal more examples of specific parasites.