Coordinator : Catherine Souty-Grosset
Reproduction strategies. Sex ratio biases induced by Wolbachia can potentially affect host reproduction. This question is investigated through the angle of sexual selection to predict the consequences of a shortage of males in populations. The aim is to understand host strategies and identify life history traits that are sensitive to the consequences of Wolbachia presence.
Gene flow, Strategies & population dynamics. In the Armadillidium vulgare / Wolbachia system, feminization can favor instability in host population dynamics by inducing both phases of populations expansion or extinction. High density phases induce a risk increase in individual survival by a decrease in available resources at the time of reproduction, which can favor individuals that are capable of higher dispersion. Hence, in populations harboring Wolbachia, dispersion behavior can become an alternative response: studies are conducted by direct (dispersion in semi-natural conditions) and indirect methods (analysis of genetic structuration of host populations and Wolbachia at metapopulation and regional scales). In addition, experiments related to dispersion behavior are conducted in artificial environments to follow colonization dynamcis and characterize genetic and symbiotic status of migrants. Modelling approaches are also used.
Biodiversity & Quality of ecosystems: meadows, agricultural practices and terrestrial isopod diversity. We are conducting studies on the values of terrestrial isopods as bioindicators and management tools of meadows. This project is linked to the study of the impact of human activities on water quality (see below). In isopod communities, we analyze Wolbachia diversity and prevalence.
Biodiversity & Quality of ecosystems: conservation of crayfish in Europe. One of the goals of conservation biology is to maintain the evolutionary potential of endangered species. In this context, the use of molecular markers allows us to characterize population groups with independent evolutionary histories, thus requiring independent management programmes. The degree of population subdivision and the degree of genetic variability help us to identify population with high risks of extinction. We use as a model the white-clawed crayfish Austropotamobius pallipes. These studies, based on international collaborations promoted by the CRAYNET network, are conducted in Ireland, France, Italy and Spain.
The European CRAYNET network “European crayfish as keystone species-linking science, management and economics with sustainable environmental quality” has permitted to encourage management strategies based on the knowledge of autochtonous species, their interactions with introduced crayfish species, the control of introduced species, habitat restoration, reintroduction, law and education in Europe. Many publications are available, including the “Atlas of crayfish in Europe”.