Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2023
Höfundar / Authors: Franka Hemme, Alessandra Schnider, Margaux Vanhussel, Camille Leblanc
Starfsvettvangur / Affiliations: Hólar University
Kynnir / Presenter: Franka Hemme
Variation in reproductive success is a major determinant of fitness and thus a target of natural selection. Especially offspring performance at early life stages is influenced by maternal investment, e.g. in form of egg size and egg composition, as well as by environmental conditions. The majority of studies investigate embryonic performance in stable, simplified laboratory conditions - as to tease apart the effect of single factor - but do not necessarily have high ecological relevance. Here we tested the effect of naturally occurring environmental fluctuations and maternal investment on mean size at hatching and mean hatching success using threespine stickleback from lake Áshildarholtsvatn. Artificially crossed clutches were split in half and incubated in two locations within the lake system that contrasted in temperature and oxygen variability. While female body size and clutch size were positively correlated, mean egg size was not affected by clutch size. Neither egg size nor incubation environment appeared to affect hatching success. However, offspring body length was positively correlated with egg size and varied significantly more under unstable conditions. Thus, increased environmental variation during embryonic development negatively affects mean offspring size. This study shows the potential for incubation in the wild and highlights the importance of in situ experiments to study individuals in a biologically relevant context.