Anthropogenic hybridization between endangered migratory and commercially harvested stationary whitefish taxa (Coregonus spp.)

Evolutionary Applications

Jan Dierking²  Luke Phelps²  Kim Præbel⁴  Gesine Ramm²  Enno Prigge²  Jost Borcherding³  Matthias Brunke¹ 

[1] Landesamt für Landwirtschaft, Umwelt und ländliche Räume (LLUR), Flintbek, Germany;Research Division Marine Ecology, Research Unit Evolutionary Ecology of Marine Fishes, GEOMAR Helmholtz Centre for Ocean Research, Kiel, Germany;General Ecology & Limnology, Ecological Research Station Grietherbusch, Zoological Institute of the University of Cologne, Cologne, Germany;Department of Arctic and Marine Biology, Faculty of Biosciences Fisheries and Economics, University of Tromsø, Tromsø, Norway

关键词: admixture;    anadromous fish;    conservation;    evolutionarily significant unit;    gill raker;    introgression;    stocking;   

DOI  :  10.1111/eva.12166

来源: Wiley

【 摘 要 】

Abstract

Natural hybridization plays a key role in the process of speciation. However, anthropogenic (human induced) hybridization of historically isolated taxa raises conservation issues. Due to weak barriers to gene flow and the presence of endangered taxa, the whitefish species complex is an excellent study system to investigate the consequences of hybridization in conservation. We focused on three naturally reproductively isolated whitefish taxa in Germany: the endangered, anadromous North Sea houting (NSH) and Baltic houting (BH), which were reintroduced after local extinction, and the commercially stocked European whitefish (EW). To evaluate the genetic integrity of each taxon, source and reintroduced populations of NSH and BH, and EW populations were characterized based on two mitochondrial and 17 microsatellite loci. Additionally, we investigated gill raker counts as an adaptive phenotypic trait. Even though clear genetic and phenotypic differentiation confirmed the houtings as separate evolutionarily significant units, admixture analyses revealed an extensive hybrid zone. Hybridizations were introgressive, positively correlated with genetic diversity, and were reflected in the gill raker counts. The BH distribution range showed higher heterogeneity and stronger admixture than the NSH range. Erroneous stocking with non-native genotypes best explained these patterns, which pose challenges for the conservation of the endangered NSH and BH.

【 授权许可】

CC BY   
© 2014 The Authors. Evolutionary Applications published by John Wiley & Sons Ltd.

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