ECOLOGY EPIDEMIOLOGY AND EVOLUTION OF PARASITISM IN DAPHNIA PDF

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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I point out which features of parasites make them attractive ecological factors and why the study of parasites may add to our understanding of Daphnia biology. Given these theoretical considerations and the finding that Daphnia parasites seem to be locally adapted, one may speculate that parasites of Daphnia usually have a higher evolutionary potential than their hosts. The growing awareness that parasites are ubiquitous and may abd an important role in most natural ecosystems has changed this, as the increasing number of publications about Daphnia parasites and epibionts confirms Figure 1.

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Interestingly, the well-fed infected hosts also produced more P. A host is part of a host range if it can be infected by the parasite, ecoloby if the parasite does not do well in this host.

Thus, parasites that drastically reduce life span also considerably reduce fecundity fecundity of the living host relative to uninfected hosts of the same agewhereas parasites benign in their effect on survival were also benign in their effect on fecundity.

Arms races are a form of antagonistic coevolution. Biologically speaking, any difference in the degree to which a parasite is associated with different host species indicates some degree of specificity. They tested whether hosts are less able to show adaptive phenotypic changes against predators when parastism to C.

The same is true if fecundity reduction is considered among infected females only Carius daphniw al. When investigating potential hosts, one must consider a number of questions whose answers are not as clear-cut as the relative ease of studying host specificity in Daphnia might suggest.

Chapman and Hall ; Gandon Gandon S Local adaptation and the geometry of host-parasite coevolution.

In a first approximation, the reduction of both fecundity and survival may be seen as a general sign of host morbidity Morbidity: They found no evidence for interactions between fish and parasite with regard to host fecundity and survival. Behavior by which the zooplankton maintains a particular vertical distribution in relation to the stratification of the water light, temperature, food, predation pressure.

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In a parasitological context, transmission stage. In this chapter, I summarize what we know about parasite host ranges and host parasiism. Kairomones from several different predators have been reported to lead to adaptive morphological and life history changes in Daphnia.

Ecology, Epidemiology, and Evolution of Parasitism in Daphnia – NCBI Bookshelf

In evolutionary biology, it is important because a negative genetic correlation between two traits, both of which affect fitness, limits their response to selection a fitness-increasing evoluton in one trait is coupled with a fitness-decreasing change in the associated trait. An animal that kills its victim, the prey item, and then feeds on it to subsist until the next kill. The authors emphasize that this effect weakens parasite-mediated selection Selection: To gain a deeper understanding of a particular system, it is also helpful to take into account the consequences of specificity for the host and for the parasite.

Clonal selection is found when clones differ in their lifetime reproductive success and is epidemoology seen in the form parasitixm genotype frequency changes. From Chapter 4 Parasitism in Natural Populations onward, I end each chapter by posing open questions and highlighting major gaps in our knowledge.

This may still be disadvantageous for the host because the parasite’s interest is in host survival, while the host has to trade-off Trade-off: Often but not always parasites that perform better in their local host than other foreign or novel parasites also perform better in their local hosts than in other hosts Figures 5. This observation has been reported in several experiments Ebert b Ebert D Virulence and local adaptation of a horizontally transmitted parasite. 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.

Infected hosts stay deeper in the water than uninfected controls. Is virulence management feasible?. Some parasites appeared specific in one pond or unspecific in another pond. Much of the conceptual parts are derived from general principles of epidemiology Epidemiology: Furthermore, this parasite effect interacted both with host genotype Genotype: Every parasite has a host, but no parasite Parasite: Seasonal change in phenotype of many plankton species.

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Chapters 8 Epidemiology and 9 Population Dynamics and Community Ecology address aspects of parasitism at the population Population: To my knowledge, every attempt to test for genetic variation Genetic variation: Please review our privacy daphnoa. They include protozoans, small crustaceans, and in early summer, the larval stages of many larger organisms. Whether these findings are explained by local genetic differences or misidentification of parasites presence of cryptic species is not clear.

Transmission of horizontally transmitted parasites is usually host density dependent. Also used to describe change in the demographic structure of the population sex ratio, age and size structure, etc.

Ecology, epidemiology, and evolution of parasitism in Daphnia by Dieter Ebert

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 epldemiology study of parasitism. A central chapter of this book is “Epidemiology. In contrast to typical predators Predator: Using the appropriate statistical test, she found firm support for specificity for only one parasite species. Although there was no significant difference in the survival of infected hosts, evolutioj was a strong effect on fecundity such that C.

Locally adapted parasites show not only higher levels of damage to their local hosts but also have higher levels of transmission-stage production Ebert b Ebert D Virulence and local adaptation of a horizontally transmitted parasite.

Ecology, Epidemiology, and Evolution of Parasitism in Daphnia

Describes the observation that only a subset of hosts is susceptible to infection. Trends Ecol Evol8: Process by which certain phenotypes are favored over other phenotypes.

Author Information Authors Dieter Ebert. Macroparasites are typically parasitic helminths and arthropods. Part of the standard definition of parasitism is that parasites Parasite: Selection leads to adaptation.

By the time infected animals were collected, the ages of their infections were also different.