Asymmetric reproductive isolation in sympatric Arctic charr morphs revealed by a comprehensive examination of reproductive barriers

Datasets to characterise reproductive isolation and the absolute and relative strengths of reproductive barriers between two sympatric populations with a recent evolutionary history but extensive phenotypic and genetic differences: the planktivorous and the small-benthic morphs of Arctic charr (Salvelinus alpinus, Linneaeus 1758) from Thingvallavatn, Iceland. We estimated the importance of reproductive barriers through a fishing survey, a mate choice experiment and a common-garden experiment involving the offspring of each morph and F1 hybrids.