Marion Fayard PhD thesis

Marion Fayard

Anxiety and parasitism in an aquatic invertebrate: evolutive and mechanistic approaches

Started in october 2017


Funding: French ministry of research

Supervisor: Marie-Jeanne Perrot-Minnot ; cosupervisor: Frank Cézilly



The need to address the existence of emotions in invertebrates such as anxiety, as well as their evolutionary significance, has been recently stressed. In addition, parasites have been evoked as modulators of anxiety in vertebrates. The aim of this research project is precisely to establish the physiological basis and adaptive consequences of anxiety in the freshwater crustacean Gammarus fossarum, as well as the role of manipulative parasites in modulating anxiety. We will first establish whether infection syndrome is comparable to a ‘syndrome of anxiety’, using phenotypic engineering. We will then address the role of the serotonergic pathway in modulating anxiety. Ultimately, we should shed light upon both the adaptive function of anxiety in gammarids, and the evolution of parasitic manipulation through the modulation of such emotional state.



Gammarus fossarum, acanthocephalan parasites, syndrome of anxiety, physiology, serotonergic, adaptive consequences