Behaviour is important for the fitness of an individual animal and is a part of its phenotype. Behaviour can change in its form and function over ontogeny and due to environmental factors. The results presented here are from an experiment that investigated changes in behaviour over ontogeny and under varying food levels for individual specimen of Heterandria formosa, a small live bearing fish. The experimental fish were raised individually with food as the only manipulated environmental factor (low-food vs. high-food) and as a potential driver for the shaping of different behaviours. Behavioural differences among individuals were assessed across ontogeny with forced open field tests. Evaluating recorded tracks for movement and considering variables such as swimming speed and zonal positioning of the test fish gave valuable insights into behavioural changes over ontogeny. Furthermore, interactions between food treatments, sex and life-stage that potentially fostered differences in behaviour were identified. Food played a lesser role than expected. It shaped behaviour differently across stages and sexes in rather specific ways. Finally, repeatability of behaviour as a sign of behavioural types and within-individual and among-individual differences in behaviour were compared. These results suggest the consolidation of behaviour with age due to increased among-individual differences. The overall results underline the importance of longitudinal studies to understand the ontogenetic development of behaviour and behavioural types and to identify the role of environmental factors.
Food-dependent development of behavioural types in Heterandria formosa
Theis, S. (2017). Food-dependent development of behavioural types in Heterandria formosa. Master Thesis, Humboldt-Universität zu Berlin / Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB) in Berlin
Erschienen in: Master Thesis, Humboldt-Universität zu Berlin / Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB) in Berlin