Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2025
Erindi/veggspjald / Talk/poster E69
Höfundar / Authors: Kalina H. Kapralova (1), Quentin Horta-Lacueva (2), Sigurður S. Sanorrason (2)
Starfsvettvangur / Affiliations: 1. Tilraunastöð Háskóla Íslands í meinafræði að Keldum , 2. Háskóli Íslands
Kynnir / Presenter: Kalina H. Kapralova
In postglacial lakes, pre-zygotic barriers often evolve rapidly as populations adapt to contrasting habitats such as benthic and pelagic zones. These barriers typically arise through differences in spawning time, location, mate choice, or ecological preferences, which reduce interbreeding between morphs. Studying them, however, is difficult since spawning events are brief, often occur in inaccessible habitats, and multiple isolating mechanisms can act simultaneously. We investigated reproductive isolation between two sympatric Arctic charr (Salvelinus alpinus Linnaeus 1758) morphs from Thingvallavatn—the planktivorous and the small benthic—that share a recent evolutionary history but show marked phenotypic and genetic divergence. Using acoustic telemetry, fishing surveys, and mating experiments, we found strong evidence of asymmetric gene flow between the morphs. Reproductive isolation was nearly complete in the planktivorous charr, largely due to temporal differences in spawning habitat use, but was weaker in the small benthic morph. Moreover, barriers between the large benthic and the planktivorous/piscivorous morphs were weaker than previously assumed, underscoring the dynamic nature of isolation. Our results broadly support the prevailing view that premating barriers can evolve early during divergence, but also highlight the potential for intrinsic postzygotic barriers to emerge at the onset of ecological speciation.