Phylogenetic diversity within the endemic brown trout Duero lineage: implications for conservation and management

• Published in: Marine and freshwater research Vol. 66; no. 11; pp. 1066 - 1071
• Main Authors: Vera, M, García-Marín, J. L, Martinez, P, Bouza, C
• Format: Journal Article
• Language: English
• Published: CSIRO Publishing 01.01.2015
• Subjects: basins; drainage; genetic variation; haplotypes; humans; mitochondrial DNA; phylogeny; restriction fragment length polymorphism; rivers; Salmo trutta; Spain
• ISSN: 1323-1650; 1448-6059
• DOI: 10.1071/MF14286

Brown trout display great phenotypic and genetic variability. Use of mitochondrial DNA (mtDNA) variation has allowed the definition of seven different lineages in this species to date. One of them, the Duero lineage (DU), was initially detected in the inner section of the Duero River in Spain, where it showed a parapatric distribution with the more widely distributed Atlantic lineage (AT). Later mtDNA-RFLP (restriction fragment length polymorphism) studies detected the DU lineage in northern Spanish basins (Galicia). The aim of this work was to ascertain the origin and variability of these DU populations outside the Duero drainage. Using complete mtDNA control region sequencing, 11 novel DU haplotypes were identified. Several of them could be assigned to an endemic group in Galicia consistent with the long-time presence of the DU lineage outside the Duero River, and excluding a recent origin by human translocations. The DU haplotype group observed in north-western Iberian basins was estimated to diverge from that of the Duero River more than 100000 years ago. We therefore advocate for conservation strategies at regional and local scales rather than focussed in a single ESU as proposed in earlier works.