title: Human-aided dispersal has altered but not erased the phylogeography of the tench.
abstract: Human-aided dispersal can result in phylogeographic patterns that do not reflect natural historical processes, particularly in species prone to intentional translocations by humans. Here, we use a multiple-gene sequencing approach to assess the effects of human-aided dispersal on phylogeography of the tench Tinca tinca, a widespread Eurasian freshwater fish with a long history in aquaculture. Spatial genetic analysis applied to sequence data from four unlinked loci and 67 geographic localities (38-382 gene copies per locus) defined two groups of populations that were little structured geographically but were significantly differentiated from each other, and it identified locations of major genetic breaks, which were concordant across genes and were driven by distributions of two phylogroups. This pattern most reasonably reflects isolation in two major glacial refugia and subsequent range expansions, with the Eastern and Western phylogroups remaining largely allopatric throughout the tench range. However, this phylogeographic variation was also present in all 17 cultured breeds studied, and some populations at the western edge of the native range contained the Eastern phylogroup. Thus, natural processes have played an important role in structuring tench populations, but human-aided dispersal has also contributed significantly, with the admixed genetic composition of cultured breeds most likely contributing to the introgression.
authors.affiliation: Laboratory of Fish Genetics, Department of Vertebrate Evolutionary Biology and Genetics, Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic Liběchov, Czech Republic ; Department of Zoology, Faculty of Science, Charles University Prague, Czech Republic.
authors.forename: Zdeněk
authors.initials: Z
authors.lastname: Lajbner
authors.affiliation: University of South Bohemia, České Budějovice, Faculty of Fisheries and Protection of Waters, Research Institute of Fish Culture and Hydrobiology at Vodňany Czech Republic.
authors.forename: Otomar
authors.initials: O
authors.lastname: Linhart
authors.affiliation: Laboratory of Fish Genetics, Department of Vertebrate Evolutionary Biology and Genetics, Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic Liběchov, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Kotlík
keywords: Tinca tinca; intron; mtDNA; secondary contact; species range; stocking