Project Details
Projekt
Hazardous host-finding: Comparative study of transmission abilities and predator evasion in parasites
Applicant
Dr. Christian Selbach
Subject Area
Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions
Term
from 2016 to 2019
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 325767530
Parasites are important and integral elements of ecosystems. The successful transmission from one host to another plays a decisive role for the completion of the life cycle (and thus for the fitness) of parasites. Due to the differences in life cycles and environmental conditions, parasite transmission stages have evolved a wide diversity of sizes, shapes or behaviors, even among closely related taxa. With 25,000 species parasitizing a variety of hosts, digenetic trematodes are ideal model systems to study the ecology and evolution of mobile transmission stages because they are the most common eukaryotic pathogens in aquatic systems and there is huge variation in the size and morphology of their free-living transmission stages, known as cercariae. Furthermore, recent studies have stressed the role of the cercariae as important energy resources for possible predators. The short-lived cercariae must therefore be able to find and infect a suitable host within a limited time window whilst evading predators. Both factors influence the success of individual parasite species and should thus shape the parasite communities of ecosystems. However, to what extent this happens under natural conditions is still poorly understood and key issues remain untested, e.g. what role predators have on the transmission success of individual trematode species, and whether or not this may explain different trematode community structures in environments rich in predatory species. Furthermore, climate change is believed to have significant impact on ecosystems and its parasites, and some pathogens might benefit from these developments. However, we do not yet know specifically how parasite transmission strategies will be affected by changing environmental conditions. The project aims at testing the hypotheses that cercarial transmission and predation shape trematode communities, and that temperature changes will have significant effects on these processes. In order test this, standardized laboratory and mesocosm experiments on the specific dispersal capabilities of free-swimming cercariae and the effects of their main predators in freshwater environments will be performed under different temperature scenarios. Connecting these results with available data on host, parasite and predator community structure from well-sampled freshwaters in Otago, New Zealand will provide valuable insight into the structuring forces that determine parasite dispersal and thus shape these ecosystems parasite communities.
DFG Programme
Research Fellowships
International Connection
New Zealand
