Auteurs, date et publication :
Auteurs J. F. Le Galliard , J. M. Guarini , F. Gaill
Date : 2025
Catégorie(s)
#CNRS #Ecotron IleDeFrance #ENS #PLANAQUAAuteurs, date et publication :
Auteurs B. Gauzens , E. Thebault , G. Lacroix , S. Legendre
Publication : Journal of The Royal Society Interface
Date : 2015
Volume : 12
Issue : 106
Pages : 20141176-20141176
Catégorie(s)
#CNRS #ENS #PLANAQUARésumé
Un ensemble coordonné de plateformes ouvertes la recherche internationale en écotoxicologie : Analyse et Expérimentation sur les Ecosystèmes – France. Colloque « Construire le réseau ANTIOPES 2.0 - La toxicologie et l’écotoxicologie prédictives : de l’appliqué à l’opérationnel »
Auteurs, date et publication :
Auteurs Christian Mougin , Didier Azam , Thierry Caquet , Nathalie Cheviron , Samuel Dequiedt , Jean-François Le Galliard , Olivier Guillaume , Sabine Houot , Gérard Lacroix , Francois Lafolie , Pierre-Alain Maron , Radika Michniewicz , Christian Pichot , Lionel Ranjard , Jacques Roy , Bernhard ZELLER , Jean Clobert , Andre Chanzy
Date : 2016
Catégorie(s)
#CNRS #Ecotron IleDeFrance #ENS #PLANAQUARésumé
The "PLAteforme expérimentale Nationale d'écologie
AQUAtique" is a multi-scale experimental infrastructure created in 2011
to make possible the analysis of human disturbance on aquatic
biodiversity, community structure, and ecosystem functioning. It is
funded by the "Investissements d'avenir Equipex" program and is partner
of the ANAEE-France research infrastructure. PLANAQUA provides the
scientific community with access to experimental highly instrumented
platforms available year round through calls for projects open to all
researchers around the world. It includes: 1) Microcosms (1-6 L),
developed for studying plankton ecology and physiology under highly
controlled environmental conditions in the dedicated laboratory or in
the climatic rooms of the Ecotron IleDeFrance. Organisms and ecosystems
activity and dynamics are precisely monitored by a series of dedicated
sensors and instruments. 2) Mesocosms (1-15 m3), have a high degree of
replication. They are installed outdoors and can house complex
communities of organisms. Among them a series of twelve is equipped with
beaters that generate waves, making possible to control the physical
structure of the water column thus to study the link between physical
constraints and functioning of aquatic systems. 3) Macrocosms, sixteen
artificial lakes (650 m3) dedicated to understand the functioning of
complex natural communities with heterogeneous spatial distributions;
they will allow ascertaining the consequences of anthropogenic pressures
on biodiversity, up to the top of the food chains. They are equipped
with automated sensors and data loggers for high-frequency data
collection of the main physical-chemical parameters. PLANAQUA is located
at the CEREEP research center (CNRS-ENS, UMS 3194) near Paris.
Keywords: Aquatic ecosystems functioning and dynamics, plankton
eco-physiology, biodiversity, environmental changes, experimental
platform, multi-scale studies, instruments and sensors
Auteurs, date et publication :
Auteurs Sarah Fiorini , Alexis Millot , Simon Chollet , Florent Massot , Jean-François Le Galliard , Emma Rochelle-Newall , Gerard Lacroix
Date : 2018
Volume : 20
Pages : 9724
Catégorie(s)
#CNRS #Ecotron IleDeFrance #ENS #PLANAQUARésumé
Although the impacts of eutrophication on freshwater biodiversity are
relatively well known, how eutrophication impacts the quality of
dissolved organic carbon (DOC) is less known, despite its importance for
microbial nutrition. Chromophoric dissolved organic matter (CDOM) is the
fraction of the bulk DOC pool that absorbs light and shifts in the
absorption and fluorescence of this component indicate an alteration in
the quality of the DOC present. Here we looked at the impact of small
phosphorus additions on CDOM absorption and fluorescence in a series of
16, newly constructed and filled, experimental lakes (Plateforme
Planaqua, UMS CEREEP, France). Eight of the lakes received small
additions (+ 100 µM) of phosphorus during late spring and summer
2015. We show that there was a distinct seasonal pattern to DOC and to
all measured CDOM parameters, regardless of nutrient status. We also
show that despite a lack of significant difference between the lakes in
terms of DOC concentrations, there were striking differences in the
carbon-normalised CDOM parameters. For example, we observed a
significant increase in the carbon normalized absorption at 254 nm
(SUVA254) in the lakes with addition of P, this was also the case for
fluorescence (ex350/em450) normalized to carbon concentration. These
changes were also accompanied by shifts in the relative intensities of
the components in the fluorescence excitation-emission matrices (EEM).
We propose that even small shifts in phosphorus availability can induce
strong shifts in carbon quality and that this may well have
repercussions up the food web should this more aromatic CDOM prove to be
less bioavailable. These results also imply that the brownification
observed in lakes in northern Europe may also be partially due to small
shifts in nutrient concentrations combined with increased carbon and
suspended solids imports from the surrounding catchments.
Auteurs, date et publication :
Auteurs Emma Rochelle-Newall , Lydie Blottière , Colombe Consortium
Date : 2018
Volume : 20
Pages : 9464
Catégorie(s)
#CNRS #ENS #PLANAQUARésumé
A trophic radiation in the South-American annual killifish genus Austrolebias has led to the evolution of large specialized piscivores from small generalized carnivores. It has been proposed that this occurred in a single series of vicariant speciation events. An alternative hypothesis is denoted giant-dwarf speciation: piscivores would have evolved in sympatry by character displacement and cannibalism. We test the plausibility of both scenarios using size measures combined with distributional data and new phylogenetic trees based on mitochondrial and nuclear molecular markers. Our analysis uses historical biogeography models and Ornstein-Uehlenbeck processes describing trait evolution across the posterior distributions of phylogenetic trees. Large species most likely evolved three times from small ones. For the clade containing A. elongatus, we argue that vicariance was not involved in the origin of these large and specialized piscivores. They experience stabilizing selection with an optimum shifted towards larger bodies and longer jaws. The branch leading to this clade has the fastest evolving jaw lengths across the phylogeny, in agreement with expectations for giant-dwarf speciation. For A. wolterstorffi, the support for giant-dwarf speciation is weaker. When the species is placed at the root of Austrolebias, ancestral reconstructions are unreliable and vicariance cannot be ruled out. For the remaining large species, we can reject vicariance and giant dwarf speciation. Our results give rise to two new additional scenarios for the evolution of specialized piscivores. In the first, two successive speciation events in sympatry or parapatry produced large and piscivorous species. In the second, the immigration of a different annual killifish genus (Cynopoecilus) in the Patos area of endemism has contributed to in-situ diversification of Austrolebias species.
Auteurs, date et publication :
Auteurs Tom Van Dooren , Henri A. Thomassen , Femmie Smit , Andrew J. Helmstetter , Vincent Savolainen
Publication : bioRxiv
Date : 2018
Pages : 121806
Catégorie(s)
#CNRS #ENS #PLANAQUARésumé
Reconstructions of evolutionary and historical biogeographic processes can improve our understanding of how species assemblages developed and permit inference of ecological drivers affecting coexistence. We explore this approach in Austrolebias, a genus of annual fishes possessing a wide range of body sizes. Regional assemblages composed of different species with similar size distributions are found in four areas of eastern South America. Using phylogenetic trees, species distribution models and size data we show how trait evolution and historical biogeography have affected the composition of species assemblages. We extend age-range correlations to improve estimates of local historical biogeography. We find that size variation principally arose in a single area and infer that ecological interactions drove size divergence. This large-size lineage spread to two other areas. One of these assemblages was likely shaped by adaptation to a new environment, but this was not associated with additional size divergence. We found only weak evidence that environmental filtering has been important in the construction of the remaining assemblage with the smallest range of sizes. The repeated assemblage structures were the result of different evolutionary and historical processes. Our approach sheds light on how species assemblages were built when typical clustering approaches may fall short.
Auteurs, date et publication :
Auteurs Andrew J. Helmstetter , Tom J. M. Van Dooren , Alexander S. T. Papadopulos , Javier Igea , Armand M. Leroi , Vincent Savolainen
Publication : bioRxiv
Date : 2018
Pages : 436808
Catégorie(s)
#CNRS #ENS #PLANAQUARésumé
Studying variation in life-history traits and correlated behaviours, such as boldness and foraging (i.e., pace-of-life syndrome), allows us to better understand how these traits evolve in a changing environment. In fish, it is particularly relevant studying the interplay of resource abundance and size-selection. These are two environmental stressors affecting fish in natural conditions, but also associated with human-induced environmental change. For instance, fishing, one of the most important threats for freshwater and marine populations, results in both higher mortality on large-sized fish and reduced population density.
Auteurs, date et publication :
Auteurs Beatriz Diaz Pauli , Sarah Garric , Charlotte Evangelista , L. Asbjørn Vøllestad , Eric Edeline
Publication : BMC Evolutionary Biology
Date : 2019
Volume : 19
Issue : 1
Pages : 127
Catégorie(s)
#CNRS #ENS #PLANAQUARésumé
Anthropogenic perturbations such as harvesting often select against a large body size and are predicted to induce rapid evolution toward smaller body sizes and earlier maturation. However, body-size evolvability and, hence, adaptability to anthropogenic perturbations remain seldom evaluated in wild populations. Here, we use a laboratory experiment over 6 generations to measure the ability of wild-caught medaka fish (Oryzias latipes) to evolve in response to bidirectional size-dependent selection mimicking opposite harvest regimes. Specifically, we imposed selection against a small body size (Large line), against a large body size (Small line) or random selection (Control line), and measured correlated responses across multiple phenotypic, life-history, and endocrine traits. As expected, the Large line evolved faster somatic growth and delayed maturation, but also evolved smaller body sizes at hatch, with no change in average levels of pituitary gene expressions of luteinizing, follicle-stimulating, or growth hormones (GH). In contrast, the Small medaka line was unable to evolve smaller body sizes or earlier maturation, but evolved smaller body sizes at hatch and showed marginally significant signs of increased reproductive investment, including larger egg sizes and elevated pituitary GH production. Natural selection on medaka body size was too weak to significantly hinder the effect of artificial selection, indicating that the asymmetric body-size response to size-dependent selection reflected an asymmetry in body-size evolvability. Our results show that trait evolvability may be contingent upon the direction of selection and that a detailed knowledge of trait evolutionary potential is needed to forecast population response to anthropogenic change.
Auteurs, date et publication :
Auteurs Clémentine Renneville , Alexis Millot , Simon Agostini , David Carmignac , Gersende Maugars , Sylvie Dufour , Arnaud Le Rouzic , Eric Edeline
Publication : Ecology and Evolution
Date : 2025
Volume : 10
Issue : 19
Pages : 10571-10592
Catégorie(s)
#CNRS #ENS #PLANAQUARésumé
Anthropogenic change in the abundance or identity of dominant top predators may induce reorganizations in whole food webs. Predicting these reorganizations requires identifying the biological rules that govern trophic niches. However, we still lack a detailed understanding of the respective contributions of body size, behaviour (e.g. match between predator hunting mode and prey antipredator strategy), phylogeny and/or ontogeny in determining both the presence and strength of trophic interactions. Here, we address this question by measuring zooplankton numerical response to fish predators in lake enclosures. We compared the fit to zooplankton count data of models grouping zooplankters based either on 1) body sizes, 2) antipredator behaviour, 3) body size combined with antipredator behaviour, or on 4) phylogeny combined with ontogeny (i.e. different life stages of copepods). Body size was a better predictor of zooplankton numerical response to fish than antipredator behaviour, but combining body size and behaviour provided even better predictions. Models based on phylogeny combined with ontogeny clearly outperformed those based on other zooplankton grouping rules, except when phylogeny was poorly resolved. Removing ontogenetic information plagued the predictive power of the highly-resolved (genus-level) phylogenetic grouping but not of medium-resolved or poorly-resolved phylogenetic grouping. Our results support the recent use of phylogeny as a superior surrogate for traits controlling trophic niches, and further highlight the added value of combining phylogeny with ontogenetic traits. Further improvements in our mechanistic understanding of how trophic networks are shaped are bound to uncovering the trophic traits captured by phylogeny and ontogeny, but that currently remain hidden to us. This article is protected by copyright. All rights reserved.
Auteurs, date et publication :
Auteurs Florian Vincent , Andrea Bertolo , Gérard Lacroix , Maud Mouchet , Eric Edeline
Publication : Oikos
Date : 2025
Volume : n/a
Issue : n/a