Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2025
Erindi/veggspjald / Talk/poster E72
Höfundar / Authors: Franka Hemme (1), Camille Leblanc (2), Margaux Vanhussel (3,4), Alessandra Schnider (2,5)
Starfsvettvangur / Affiliations: 1) Lund University, Lund, Sweden. 2) Hólar University, Sauðárkrókur, Iceland. 3) Université de Liège, Liège, Belgium. 4) University of Exeter, Exeter, United Kingdom. 5) University of Iceland, Reykjavik, Iceland
Kynnir / Presenter: Alessandra Schnider
Reproductive success is a key determinant of fitness and a direct target of natural selection. Offspring performance at early life stages depends on maternal investment and environmental conditions. Increasing environmental fluctuations due to climate change place additional stress on egg quality during maturation and embryonic development, yet most studies still test embryonic performance under stable laboratory conditions with limited ecological relevance. We tested the effects of naturally occurring environmental fluctuations on hatching success and offspring size in threespine stickleback from Lake Áshildarholtsvatn, Iceland. Using a split-clutch design, eggs from 15 families were incubated in two lake sites differing in temperature and dissolved oxygen variability. Hatching success and body length were measured at the end of embryonic development (swim-up and complete yolk absorption). Mean hatching success and mean offspring size did not differ between stable and unstable environments. However, offspring size exhibited substantially greater variation under fluctuating conditions, resulting in more phenotypic diversity within and among clutches. Thus, environmental fluctuations during embryonic development can increase variance in early-life traits without necessarily altering average traits. Fitness consequences of greater body size variation at this stage are unknown but may increase resilience to environmental variability and improve fitness for offspring and mothers.