Hybridization mechanisms between the endangered marble trout (Salmo marmoratus) and the brown trout (Salmo trutta) as revealed by in-stream experiments

Autor: Jean-François Rubin, Patrick Berrebi, Alain J. Crivelli, Gilles Poizat, Torben Meldgaard, Dusan Jesensek
Přispěvatelé: Ecosystèmes lagunaires : organisation biologique et fonctionnement (ECOLAG), Université Montpellier 2 - Sciences et Techniques (UM2)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Centre National de la Recherche Scientifique (CNRS), Station Biologique de la Tour du Valat, Anglers' Society of Tolmin, Society of Tolmin, Ecole d'ingénieurs HES, HES, Institut des Sciences de l'Evolution de Montpellier (UMR ISEM), École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre National de la Recherche Scientifique (CNRS)-Institut de recherche pour le développement [IRD] : UR226
Jazyk: angličtina
Rok vydání: 2007
Předmět:
Zdroj: Biological Conservation
Biological Conservation, Elsevier, 2007, 136 (4), pp.602-611. ⟨10.1016/j.biocon.2007.01.004⟩
ISSN: 0006-3207
DOI: 10.1016/j.biocon.2007.01.004⟩
Popis: International audience; Populations of the marble trout (Salmo marmoratus) are critically declining due to introgression by brown trout (S. trutta) strains. Hybrids between the two forms are fertile and presently predominant in most rivers of the species' range. The involved hybridization mechanisms have been studied through two large scale in-stream experiments (Driselpoh and Stopnikarca) as 50% of each species have been stocked at the age of one year in fishless streams, each fish being individually marked. Diagnostic molecular markers were applied to test a partial reproductive isolation between the two species. Emphasis was put on survival and growth patterns of stocked fish (parental generation) as well as on fish hatched within the stream (F1 generation). No evidence of a partial reproductive barrier between the two species was observed. Survival of the parental generation depended on the year in both streams, as well as on the species in Stopnikarca, but was identical for both species in Driselpoh. In both streams survival of instream hatched individuals measured from 0+ to 2+ was lower for brown trout. In Driselpoh, F1 0+, 1+ and 2+ hybrids were larger than pure individuals. Larger hybrids were only observed in Stopnikarca when analyses focused on individuals in inter-specific competition suggesting that heterosis and stress effects may explain the observed size differences. Our results point out important ecological differences between marble and brown trout and have shown that hybridization can easily take place. The findings indicate that high F1 hybrid presence, survival and heterosis effects may impede marble trout rehabilitation in the area.
Databáze: OpenAIRE
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