Genetic patchiness in European eel adults evidenced by molecular genetics and population dynamics modelling

• Published in: Molecular Phylogenetics and Evolution
• Main Authors: Pujolar, José Martin, Bevacqua, Danièle, Andrello, Marco, Capoccioni, Fabrizio, Ciccotti, Eleonora, de Leo, Giulio A., Zane, Lorenzo
• Other Authors: Dipartimento di Biologia, Università degli Studi di Padova = University of Padua (Unipd), Dipartimento di Scienze Ambientali, Università degli studi di Parma = University of Parma (UNIPR), Laboratoire d'Ecologie Alpine (LECA), Université Joseph Fourier - Grenoble 1 (UJF)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Roma Tor Vergata Roma
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2011
• Subjects: adult eels; anguilla anguilla; european eel; genetic patchiness; population dynamics modelling; [SDV]Life Sciences [q-bio]; Anguilla anguilla; European eel
• Online Access: https://hal.inrae.fr/hal-02643645; https://doi.org/10.1016/j.ympev.2010.11.019

International audience Disentangling the demographic processes that determine the genetic structure of a given species is a fundamental question in conservation and management. In the present study, the population structure of the European eel was examined with a multidisciplinary approach combining the fields of molecular genetics and population dynamics modelling. First, we analyzed a total of 346 adult specimens of known age collected in three separate sample sites using a large panel of 22 EST-linked microsatellite loci. Second, we developed a European eel-specific model to unravel the demographic mechanisms that can produce the level of genetic differentiation estimated by molecular markers. This is the first study that reveals a pattern of genetic patchiness in maturing adults of the European eel. A highly significant genetic differentiation was observed among samples that did not follow an Isolation-by-Distance or Isolation-by-Time pattern. The observation of genetic patchiness in adults is likely to result from a limited parental contribution to each spawning event as suggested by our modelling approach. The value of genetic differentiation found is predicted by the model when reproduction occurs in a limited number of spawning events isolated from each other in time or space, with an average of 130-375 breeders in each spawning event. Unpredictability in spawning success may have important consequences for the life-history evolution of the European eel, including a bet-hedging strategy (distributing reproductive efforts over time) which could in turn guarantee successful reproduction of some adults.