title: Biological influences on inter- and intraspecific isotopic variability among paired chondrostome fishes.
abstract: This study aimed at examining resource partitioning both at the inter- and intraspecific levels between paired chondrostome fishes: Chondrostoma nasus, the nase, C. toxostoma, the sofie, and their hybrid. The study was performed in the south of France and concerned a main river (the Durance River) and a tributary (the Buech River). In these rivers, C. nasus was an introduced species, originating in central Europe, and C. toxostoma was an endemic congener, in the south of France. Stable isotope analysis was used to analyse trophic and spatial niches. Isotopic differences indicated that individuals from the three taxa (C. nasus, C. toxostoma and their hybrid) have different spatial origins. At the interspecific level, the different chondrostomes originating from the Buech River showed a high level of trophic niche overlap. At the intraspecific level, nase individuals originating from the different spatial origins showed a resource polymorphism; differences in morphology were associated with variation in behaviour and life history traits. Their coexistence was a likely outcome of resource polymorphism. This study provides an example of the importance of considering the link between intra- and interspecific interactions to gain an understanding of the mechanisms driving the coexistence of species-pairs.
authors.affiliation: UMR IMEP-CNRS 6116, université de Provence, case 36, 3, place Victor-Hugo, 13331 Marseille cedex 3, France. mdurbec1510@yahoo.fr
authors.forename: Martial
authors.initials: M
authors.lastname: Durbec
authors.forename: Bénédicte Nguyen
authors.initials: BN
authors.lastname: The
authors.forename: Jonathan
authors.initials: J
authors.lastname: Grey
authors.forename: Christopher
authors.initials: C
authors.lastname: Harrod
authors.forename: Nicolas
authors.initials: N
authors.lastname: Stolzenberg
authors.forename: Rémi
authors.initials: R
authors.lastname: Chappaz
authors.forename: Laurent
authors.initials: L
authors.lastname: Cavalli
mesh_terms: D025041:Animal Migration; D000818:Animals; D003530:Cyprinidae / Q000502:physiology*; D017753:Ecosystem; D004777:Environment; D005602:France; D007448:Invertebrates; D007554:Isotopes; D019021:Natural History; D009693:Nucleic Acid Hybridization; D011110:Polymorphism, Genetic; D011153:Population; D013045:Species Specificity; D013048:Specimen Handling
chemical_list: D007554:Isotopes