Trial lecture: 'Symbiosis in Aquatic invertebrates: drivers and ecological functions of parasitism'
Time and place: Mar. 21, 2025 10:15 AM, Nucleus, Bikuben, Kristine Bonnevies hus
Main research findings:
Parasitism profoundly impacts ecosystems yet has historically been neglected in the largest ecosystem on Earth, the marine pelagic waters. Copepods are abundant zooplankton that play important roles in global carbon cycling. Several microbial eukaryotic parasites infect copepods, but the significance of these infections is poorly understood. In my thesis, I used a combination of modelling, field, and experimental approaches to study these parasite-host systems.
The model suggests that parasites can regulate copepod populations and identifies key parasite and host properties that facilitate outbreaks. Using metabarcoding, many of the known parasites of copepods were found in the Oslofjord, Norway, where they remain throughout the year despite a seasonally fluctuating copepod host community. The thesis also provides quantitative data on the fitness costs of an enigmatic parasite, the Yellow-Hyphal Parasite, and describes its biology. Finally, we find that parasites are present in a long-standing copepod culture, which holds great promise for future experimental studies, a major hurdle in this research field. The research helps bridge the gap between parasitology and pelagic ecology, and contributes to the growing consensus that parasitism is widespread and ecologically significant, in copepods and in the pelagic realm at large.
Adjudication committee
Prof. Monika Quinones Winder, Department of Ecology, Environment and Plant Sciences, Stockholm University
Prof. Torkel Gissel Nielsen, Technical University of Denmark, National Institute of Aquatic Resources
Assoc. Prof. Adriana Lopes dos Santos, Department of Biosciences, University of Oslo
Chair of defense
Prof. Bente Edvardsen, Department of Biosciences, University of Oslo
Supervisors
Prof. Josefin Titelman, Department of Biosciences, University of Oslo
Prof. Tom Andersen, Department of Biosciences, University of Oslo
Prof. Lasse Riemann, Department of Biology, University of Copenhagen
Prof. Stein Kaartvedt, Department of Biosciences, University of Oslo