Abstract
Members of the Saprolegniaceae are ubiquitous in freshwater environments and can greatly influence populations of aquatic animals, e.g. fish, amphibians and crustaceans. I plan to study the two most important genera, Saprolegnia and Aphanomyces.The proposed work has four specific aims: (1) to study the taxonomy of Saprolegnia and in particular the problematic diclina-parasitica complex, (2) to analyse the role of the fish community on the population biology of Saprolegnia and (3) to study those Aphanomyces species that normally can be encountered on crustaceans and fish with respect to genetics and physiology (4) to study interactions between the parasite A. astaci and its hosts in mixed populations of signal crayfish and noble crayfish. I will try to determine if there are specialised asexual Saprolegnia species (such species are morphologically indistguishable and require a molecular approach) affecting particular types of fish and to which extent the fish community is influencing which types of Saprolegnia and Aphanomyces species are present. These goals are achieved with a combination of sampling in the field, gene sequencing and analysis but in addition also experiments in the laboratory on crucial steps in the reproductive cycles of the organisms.
Sweden