Annemie Doliwa

Scientist

Faculty of Biology
Aquatic Ecology
Universitätsstrasse 5
D-45141 Essen
Germany

PhD thesis: Identifing protistan parasite communities to estimate the degradation and recovery of rivers under the analyzed stressors

Not only do parasites play various important roles in ecosystems, but they can also offer valuable information about their environment and can be used as bioindicators for environmental stressors. Presumably their diversity and infection rates in an ecosystem can reflect its condition.

The CRC 1439 RESIST opens up the opportunity to investigate the connections between protistan parasites, their hosts and environmental stressors. This leads to the central question for project A07 of what influence these stressors have on the species richness of the protistan parasite communities and on their infection rates in metazoan hosts. It can be assumed that an increase in stressors reduces species richness, but more metazoan individuals will be infected with certain protistan parasite species. The extent to which a parasite is affected could depend on its traits, such as the number of hosts it needs to complete its life cycle, how specialized the parasite is on its hosts, or whether it is an internal or external parasite. A broad spectrum of parasitic groups is taken into account, namely the classical or “long-branch” Microsporidia, as well as the “short-branch” Microsporidia, Apicomplexa, Chytridiomycetes, Oomycetes and the Vampyrellida.

The aim of this project is to identify the main players within these protistan parasite communities that can be used to estimate the degradation and recovery of rivers under the analyzed stressors.