Reference : Stable isotope composition spatial variability at microhabitat scale of macrofauna in...
Scientific congresses and symposiums : Poster
Life sciences : Aquatic sciences & oceanology
Life sciences : Environmental sciences & ecology
Stable isotope composition spatial variability at microhabitat scale of macrofauna inhabiting a tropical freshwater stream (Pérou River, Guadeloupe)
Lepoint, Gilles mailto [Université de Liège - ULiège > Département de Biologie, Ecologie et Evolution > Océanologie >]
Marichal, Nicolas [Université de Liège - ULiège > Biologie, Ecologie, Evolution > Océanologie > >]
Troupin, Charles mailto [Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > GeoHydrodynamics and Environment Research (GHER) >]
Monti, Dominique [University of Antilles and Guyana > DYNECAR > > >]
ISOECOL 2012 (Application of stable isotopes in Ecology
from 20-08-12 to 24-08-12
Institut Universitaire Européen de la Mer
[en] tropical ecosystem ; stable isotopes ; decapods ; Guadeloupe
[en] The spatial variability of isotopic (C and N) composition of freshwater fauna was assessed in a small and pristine tropical stream (Pérou River, Guadeloupe). In order to assess this variability, a section of 80 m was mapped and divided in quadrate (n= 132). Microhabitats (i.e. depth, hydrodynamic facies, presence of litter) were defined for each quadrate. Electric fishing was performed in each quadrate and individual isotopic measurements using EA-IRMS were done using abdominal muscles for crustaceans and lateral muscles for fishes. Isomap was generated for each species. Potential food sources (green ripisylve, macrophytodetritus, epilithic biofilm and deriving organic material) were sampled and analyzed for their isotopic composition. SIAR mixing model was applied to try to delineate isotopic and trophic variability in relation to microhabitat in this river section.
Nine species were recorded belonging to four decapod families (n= 8 species) and one fish family (n= 1 species). This fauna, dominated by crustaceans, is typical of high and medium elevations of Caribbean rivers in relatively pristine area. In these turbulent biotopes, species encountered are strongly linked to the hydrological characteristics of their microhabitat and have well defined preferenda.
Isotopic compositions of ripisylve material, of deriving matter and of autochtonous biofilm were significantly different for both 13C values and 15N values, allowing to discriminate their respective contributions to consumer diet. Epilithic and epiphytic biofilm appeared to contribute significantly to these diets, but most of the species showed evidence for litter material contribution too. Species repartition and their respective diet were evident at microhabitat scale and strongly related to hydrological regime.
DYNECAR (UAG) ; Centre Interfacultaire de Recherches en Océanologie - MARE
Fondation pour la Recherche sur la Biodiversité (FRB - France)
COTEAU : COnnectivité Terre-EAU : Importance des apports terrestres dans le maintien de la biodiversité en crustacés et poissons des rivières antillaises (2010-2012, S. Gobert & G. Lepoint, promoteur : D. Monti, U. Guyane-Antilles)
Researchers ; Students

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