Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2019

Erindi/veggspjald / Talk/poster E27

Geographic patterns of genetic variation among populations of Arctic charr and brown trout in Iceland

Höfundar / Authors: Han Xiao (1), Marcos Lagunas (1), Jóhannes Guðbransson (1,2), Bjarni K. Kristjánsson (3), Sigurður H. Árnason (1,3), Magnús Jóhannson (2), Benoný Jónsson (2), Arnar Pálsson (1), Sigurður S. Snorrason (1), Zophonías O. Jónsson (1)

Starfsvettvangur / Affiliations: 1. Líf- og umhverfisvísindastofnun Háskóla Íslands, 2. Hafrannsóknastofnunin, 3. Háskólinn á Hólum

Kynnir / Presenter: Sigurður S. Snorrason

As the glacial ice retreated vast new waterways were formed in the boreal and Arctic region. Northern freshwater fish colonized these new habitats and many populations, especially those occupying inland headwaters, became isolated as impassable waterfalls formed downstream. Iceland harbours a multitude of Arctic charr (Salvelinus alpinus) inland populations and several brown trout (Salmo trutta) populations that presently are isolated from gene flow from lowland populations. Using SNP variation data obtained with ddRADseq we analysed the genetic variation within and among populations of Arcic charr and brown trout in several major watersheds of Iceland. For both species the data show that the major axes of variation represent divergences of isolated headwater populations. This supports the frequently forwarded assumption that impassable waterfalls in many cases formed soon after the ice retreated ca. 10ky ago. Although the lowland populations are in most cases well defined in terms of present genetic variation the differences among them are smaller most probably reflecting a history of gene flow within and between major watersheds. Further analyses, e.g. testing (i) to what extent the genetic differentiation among lowland populations reflects the sea distances between watersheds, (ii) the topography of the shorelines and (iii) major geological events are in progress.