Líffræðifélag Íslands
Líffræðiráðstefnan 2015
Erindi/veggspjald / Talk/poster E99
Coralie Delarue(1), Bjarni Kristófer Kristjánssoni(1), Katja Räsänen(2)
1. Hólar University College 2. Swiss Federal Institute of Technology in Zürich
Kynnir / Presenter: Coralie Delarue
Tengiliður / Corresponding author: Coralie Delarue (coralie@mail.holar.is)
Lake Mývatn is one of the most studied systems in Iceland. In the lake there are strong ecological gradients, e.g in temperature, depth, substrate, vegetation and clear spatial and temporal differences in invertebrate composition, which are possible prey for fishes. Adaptive divergence driven by selection is frequently related to diet and/or habitat use. Such adaptive processes which influence individual variation are important to assess as they may promote maintenance of species diversity. In Lake Mývatn, despite gene flow, feeding morphology differs among at least two morphs of threespine stickleback. It is important to study if the phenotypic diversity observed is caused by plasticity, which may inform us about adaptive potential within these populations. Important plastic responses may indicate that environmental conditions promote diversification, while less plastic responses indicate more genetic differentiation. Crosses of threespine sticklebacks from these two morphs that differ in the temperature of their breeding habitat were made and offsprings raised at different diet and temperature. After nine month, behavior and morphology were measured. Differences were found in size, gill raker morphology and sexual maturation. The result strongly indicates a mixture of genetic divergence and phenotypic plasticity. This preliminary data support the existence of two morphs in the lake. The study gives insight in processes influencing diversification of natural populations.