Research projects

 Here are descriptions of the research projects I conducted or participated in. In a nutshell, I'm interested in the evolution of adaptive responses to stressors (especially parasites and pollutants) in wild and domestic animal populations. 

In september 2014, I joined the Evolution & Biological Diversity lab at Toulouse 3 University as a tenured assistant professor. I am conducting long-term projects to better understand the adaptive responses of fish to human-driven perturbations in freshwater ecosystems. My first goal is to understand the evolutionary causes of intra-specific variability of physiology, behaviour and coloration in freshwater fishes exposed to multiple stressors. My second goal is to assess the consequences of such intraspecific variability for population resilience, pathogen spread and ecosystem health in human-altered rivers.

Labex TULIP MICROPOLL (2023-2024): Pollution and multistress effects on fish-microbiota interactions

co-PI with J White. With colleagues from LEFE (S Jean, Q Petitjean) & EDB (J White, Jessica Côte), we investigate how metal pollution  and parasites affect fish microbiota and fish health in realistic multistress conditons. We also explore wether fish skin and gut microbiota could potentially mitigate or amplify the adaptive responses to pollution in heterogenous wild populations.  Stay tuned!

ANR MULTIPAT (2022-2026): Multistress effects on trout-pathogens interactions and disease risk

PI. With colleagues from LEFE (S Hansson, S Jean, P Laffaille), EDB (G Loot, C Jézéquel), and SETE (S Blanchet), we investigate how historic metal pollution in combination with other stressors can affect emerging diseases in brown trout from the Pyrenean moutains in an EcoHealth framework.  Funding: ANR JCJC + PhD grant from Région Occitanie/Université Fédérale de Toulouse to Laurine Gouthier (supervisors: S Hansson/L Jacquin/ G Loot)


ADI POLLPAT (2021-2022) 

(main PI: S Hansson) We also received a pilot grant from the UFT/Région Occitanie to test new non-invasive methods from fish blood. Turns out that  blood is indeed a non lethal way to measure some metals (such as Cd, Pb, Cu...) and useful to assess some aspects of health (immune cells).

Projet Région GAMBOC (2022-2026): La gambusie, une espèce invasive au service de l'étude des mécanismes de tolérance à la pollution en Occitanie

Participante. Coordinatrice/PI: Emilie Farcy, Université Montpellier, MARBEC. L’objectif du projet Région consortium GambOc est d’étudier les déterminants phénotypiques, génomiques et épigénomiques de la tolérance à la pollution organique chez Gambusia holbrooki, un poisson téléostéen invasif. Financeur: Région Occitanie (programme BIODIVOC)  

IUF (2022-2026): Intraspecific variability of responses to multistress effects and emerging disease dynamics

PI. With colleagues from LEFE (S Jean, S Hansson), EDB (G Loot), and SETE (S Blanchet), we are studying the effects of water pollution and other stressors (temperature, pathogens) on fish health and emerging disease dynamics in heterogeneous wild populations, and their effects on fish evolutionary trajectories, using an EcoHealth framework. Funding: Institut Universitaire de France.

MULTIFISH Fyssen (2021): Effects of multiple stressors on fish behaviour and cognition

PI. With colleagues from LEFE (Q Petitjean, S Jean, M Cousseau) we are investigating how pollution in combination with other stressors can affect fish health and fish stable behaviours, aka personalities. Funding: Fyssen fundation

PKD project: determinants of PKD disease in the brown trout

AX project (co-PI: 2017-2021) funded by Agence de l'Eau and PKD project (participant: 2018-2021) funded by OFB. With colleagues from SETE Moulis (S Blanchet, E Duval), EDB (G Loot, C Veyssière), INRAE (E Quéméré), and the Fédération de Pêche Ariège (L Garmendia, A Lautraite), we studied the effects of an emerging pathogen Tetracapsuloides bryosalmonae on brown trout health. We aim at determining how anthropogenic disturbances (such as water warming and eutrophication) and individual characteristics (genetic and phenotypic variability) could favor the spread of the pathogen and shape the evolution of fish resistance/tolerance. 

Funding: Agence de l'Eau Adour-Garonne AEAG, Office Français de la Biodiversité OFB 

Picture: Gaël Grenouillet

PHYPAT project: Variability of responses to multiple stressors in the wild gudgeon

Main PI: 2016-2020. This is a collaborative project with several labs and colleagues (EDB, Ecolab, ENSAT, SETE, METIS). 

We investigated the effects of water pollution (pesticides, trace metals, eutrophication) on fish health at different biological levels, from molecules to the whole organism. We are testing whether some populations developed specific abilities to cope with water pollution, and how this could affect their ability to respond to pathogens in a multistress context. We are using a combination of field and lab approaches (population comparisons, reciprocal transplantations within rivers and controlled exposure in the lab) in the wild gudgeon Gobio occitaniae. Jessica Côte (postdoc) and Quentin Petitjean (PhD candidate) joined the team. Suivez le projet sur le site "Des Poissons et des Hommes" ! (en français) Rapport technique pour les gestionnaires des milieux (en français) ICI

Funding: Agence de l'Eau Adour-Garonne (PI), CNRS EC2CO (co-PI), ZA PYGAR (co-PI)

Intraspecific variability of coloration and alternative strategies in human-altered rivers

co-PI FRAIB (2015). This is a transversal project I have been conducting along side my other projects these last years. With collaborators at EDB (Jessica Côte), EcoLab (S Jean),  INRA St-Pée-sur-Nivelle (J Labonne, C Tentelier) and CNRS SETE Moulis (S Blanchet), we are studying the biological significance of intraspecific variability and melanin-based coloration in natural populations of fish. We are now expanding our study zone to better understand how genetic variations and melanin signals could reflect alternative strategies to multiple stressors in human altered rivers.

For instance, we highlighted strong negative (but reversible) effects of water eutrophication of fish melanin-based coloration through plasticity, suggesting an "economy of pigment" hypothesis in disrupted freshwater habitats. We wish to pursue this line of research, although no specific funding is devoted to this question so far. To be continued...

PAST PROJECTS

Evolution of behavioral responses to parasites and pollution in Trinidadian guppies

Postdoc 2013-2014. McGill University, Montréal, Fyssen fellowship

With Dr Andrew Hendry and Dr Simon Reader

The aim of this postdoctoral project was to better understand the  effects of parasites on the evolution of behavioral strategies across generations. Indeed, parasites can strongly impact the costs and benefits of social and risk-taking strategies. By comparing different populations of guppys and infecting them experimentally with Gyrodactylus ectoparasites we showed that parasites could act as selective agents on host personality traits and social interactions, therefore influencing the evolution of consistent syndromes in the wild. We also showed that oil pollution could act as a selective agent on behavioural evolution in naturally-exposed wild populations of guppies in Trinidad. 


Below are nice Trinidadian guppy fish coevolving with Gyrodactylus ectoparasites in Trinidad rivers. Guppies are easy to breed in captivity and have short life cycles that cause rapid evolutionary responses to environmental changes. Moreover, there are different lineages of guppies having evolved with or without parasites, and with or without oil-pollution, giving us access to totally independent instances of potential evolutionary divergence between contrasting environments

ATER PROJECT: Manipulation of gammarid behavior by acanthocephalan parasites

Some parasites have the ability to manipulate the behavior of their intermediate host, which enhances their transmission to the next hosts. However, it is not clear if such behavioral alterations are true adaptations or merely side-effects of the infection. The aim of this ATER research project was to better understand the adaptive significance of host behavioral manipulation by acanthocephalan parasites. I focused on P. minutus parasite, which has a complex life cycle relying on predation of gammarid intermediate hosts by waterbirds. We combined experiments in the field and in the lab to test the hypothesis that the parasite could trigger fine-tuned alterations that could specifically target definitive bird predators while limiting predation by non-host fish predators at the same time. Contrary to our expectations, the biotic context did not fine-tuned parasite-induced changes. This supports a parsimonious explanation of parasite manipulation, which could have evolved as a side effect of infection to accomodate predation risks in aquatic communities.

Here is an amphipod carrying an acanthocephalan parasite (orange spot visible through the cuticle). Such parasitized amphipods have an aberrant behaviour that facilitates their predation by mallard birds that are definitive hosts for the parasite:

PhD project (2009-2011): Melanin-based coloration and life-history strategies in urban pigeons

The aim of my PhD project (which we continued for several years after my PhD defence in 2011) was to better understand the role of parasites in the evolution of host immunity across generations (maternal effects), and to understand the evolution of coloration polymorphism in heterogeneous environments. Using a combination of field work and experiments in captivity, I compared the immune and life-history strategies of differently coloured individuals to cope with parasites and food limitation in the urban environment. Results suggests that such strategies are closely linked to melanin-based coloration. This opens the exciting possibility coloration could signal alternative strategies to cope with urbanization in pigeons. More details here (PhD dissertation in french): manuscript 10.pdf


Below is a melanic feral pigeon. Our results suggest that such a dark plumage coloration could reflect an adaptation to heavily urbanized conditions: